The burden of type 2 diabetes and related complications has steadily increased over the last few decades and is one of the foremost global public health threats in the 21st century. Diabetes is one of the leading causes of chronic kidney disease and kidney failure and is an important contributor to the cardiovascular morbidity and mortality in this population. In addition, up to one in three patients who have received kidney transplants develop post-transplant diabetes, but the management of this common complication continues to pose a significant challenge for clinicians. In this review, we will describe the global prevalence and temporal trend of kidney failure attributed to diabetes mellitus in both developing and developed countries. We will examine the survival differences between treated kidney failure patients with and without type 2 diabetes, focusing on the survival differences in those on maintenance dialysis or have received kidney transplants. With the increased availability of novel hypoglycemic agents, we will address the potential impacts of these novel agents in patients with diabetes and kidney failure and in those who have developed post-transplant diabetes. The number of people with diabetes has more than doubled over the last two decades, and diabetes has become one of the predominant global health threats of the 21st century. It is estimated that more than 50 million people worldwide have diabetes, and diabetes-related complications and disability are associated with substantial economic healthcare cost and loss of productivity , with the eventual consequence of progressive kidney function decline and ensuing kidney failure . The preThe global incidence of treated kidney failure from diabetic kidney disease varies widely between countries, with the incidence ranging from as low as 10% reported in Romania up to almost 70% in Singapore and Malaysia . FigurePopulation cohort studies have consistently shown that the presence of type 2 diabetes is associated with an excess risk of mortality in patients with chronic kidney disease and kidney failure compared to those without diabetes , 34–36. The prevalence of newly diagnosed diabetes following dialysis initiation varies between 4% and 16%, with the prevalence rate generally higher in patients maintained on peritoneal dialysis –45. HoweThere is often uncertainty with regard to the suitability of kidney transplantation in patients with diabetes and kidney failure, balancing between the expected improved health outcomes from transplantation versus the reduced life expectancy of this population compared to patients without diabetes. Nevertheless, clinicians must be cognizant of the projected incremental gains in survival and improved quality of life following successful kidney transplantation compared with maintenance dialysis treatment, with modeled data showing a substantial survival benefit for patients with diabetes.In the United States Renal Data System study of 252,358 patients with treated kidney failure under the age of 70 years, kidney transplantation reduced the risk of mortality by over 70% compared to remaining on the waiting list . The projected survival gain after transplantation was over 11 years among patients with diabetes, considerably higher than the survival gain in other kidney failure patients without diabetes . Similarp = 0.28)] ] . These f= 0.28)] , 54. How= 0.28)] . The disPTDM is an established and frequent complication after kidney transplantation, occurring in between 10% and 50% of recipients in the first 12 months post-transplantation –60, withThe optimal screening method for PTDM remains unknown, with the Kidney Disease Improving Global Outcomes (KDIGO) 2009 guideline advocating fasting blood glucose, oral glucose tolerance test (OGTT), and/or glycated hemoglobin  but the frequency of screening remains unknown (level 2D evidence) . HoweverThe pathogenesis of PTDM is likely to be multifactorial, with traditional  and transplant-related risk factors contributing to this high risk Table 1.The association between abnormal glucose regulation and adverse long-term health outcomes in kidney transplant recipients is well established, with an incremental risk of allograft loss, all-cause mortality, fatal and non-fatal CVD, and/or reduced quality of life being apparent from the pre-diabetes stage to the onset of PTDM , 98–104.The landscape of diabetic kidney disease treatment has changed significantly over the past decade, particularly with the emergent evidence of the cardiac and nephroprotective benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors. The availability of SGLT2 inhibitors and other novel agents may potentially slow the upward trend of the incidence of diabetic kidney disease and improvement in diabetes-related complications 3. FiguThe optimal HBA1c target associated with a reduction in the risk of hard clinical outcomes in kidney failure patients remains unclear. A systematic review published in 2017 showed a lack of superiority of more intensive (HbA1c < 7%) compared to liberal glycemic control (HbA1c > 7%) for the outcomes of kidney failure, death, or cardiovascular complications, whereas the Action to Control Cardiovascular Risk in Diabetes (ACCORD) post-hoc analysis showed that intensive glycemic control in high-risk patients with type 2 diabetes and mild/moderate chronic kidney disease was significantly associated with over 30% increased risk of cardiovascular and all-cause mortality , 186. Thvia activity through glucagon-like peptide-1 (GLP1) receptor, improvement of sodium excretion; and reduction of tubular injury, oxidative stress, inflammation, fibrosis, and apoptosis  . In 1993GLP-1 agonists and dipeptidyl peptidase 4 (DPP4) inhibitors were developed in the mid-2000s. Systematic reviews have shown that GLP-1 agonists improved cardiovascular outcomes with reduction in MACE  and all-cause mortality  , whereas2, independent of diabetes status  trial showed that the exposure to canagliflozin reduced the risk of the primary composite endpoint of end-stage kidney disease, doubling of serum creatinine level, and death from renal or cardiovascular causes by over 30% compared to placebo . This las status , 201. Ans status . Despites status .Several novel agents  were assessed for the potential nephroprotective effect in patients with diabetic kidney disease, but these trials have been disappointing –207. StuThe optimal management strategies for the prevention or treatment PTDM remain unknown, with clinical practice guidelines generally informed by non-trial observational data . There in = 399 kidney transplant recipients with pre-transplant diabetes or PTDM) concluded that the studies were of poor quality and exhibited a high risk of bias, and the findings were unable to inform the superiority of any treatment options (n = 115), with no demonstrable benefit in improving glycemic control, allograft function, or outcome with DPP4-inhibitor (n = 67) (n = 23) (n = 110) (n = 92)  . However options . Only thnhibitor –227. Ta(n = 67) –230, rep(n = 23) , GLP1 ag(n = 23) –238, DPPn = 110) , 231–233(n = 92) –246 appeGiven the recent trial evidence on the efficacy of novel oral hypoglycemic agents in the treatment of type 2 diabetes in the general population, there is a considerable knowledge gap regarding the safety, tolerability, and efficacy of these newer agents in patients with advanced chronic kidney disease, including those maintained on dialysis or have received kidney transplants. A global collaborative effort composed of epidemiologists, clinicians, trialists, and basic science researchers is required to collect retrospective and prospective data reporting on the use of these and other novel agents in patients with kidney failure, in order to enhance our understanding of the similarities and differences in the pathogenesis of diabetes and related complications in those with kidney failure, identify and validate potential predictive biomarkers to guide evidence-based treatments, and coordinate adequately powered clinical trials to address the knowledge deficiency in the optimal treatment of patients with kidney failure and type 2 diabetes and those with PTDM.Our understanding of the incidence and prevalence of type 2 diabetes and related complications among patients with treated kidney failure has significantly advanced with the availability and analysis of big data repositories that showed that diabetic nephropathy has become one of the dominant causes of treated kidney failure worldwide. Data from multiple major linkage projects have shown that treated kidney failure patients with type 2 diabetes have a survival disadvantage compared to those without diabetes, but the magnitude of these risks remains inconsistent. Even though important progress has been made in the understanding of the mechanistic insights into the pathogenesis and ensuing novel treatments to impede kidney disease progression and reduce the burden of vascular complications attributed to diabetes in the last decade, a similar understanding of these novel treatment strategies in patients with diabetes and kidney failure maintained on dialysis or having received kidney transplants remains an elusive goal. Future global collaborative efforts are urgently required to accurately map the disease incidence and prevalence, collating precise age-, gender-, and race-specific data to inform the risk of diabetes-related complications in patients with kidney failure and to provide evidence-based recommendations in the optimal treatment strategies for these patients, including those who have developed PTDM. These data will then inform the development of a global action plan to counteract diabetic kidney disease and provide meaningful knowledge to improve outcomes for the thousands of people with treated kidney failure and diabetes.All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Myocardial regeneration in patients with cardiac damage is a long-sought goal of clinical medicine. In animal species in which regeneration occurs spontaneously, as well as in neonatal mammals, regeneration occurs through the proliferation of differentiated cardiomyocytes, which re-enter the cell cycle and proliferate. Hence, the reprogramming of the replicative potential of cardiomyocytes is an achievable goal, provided that the mechanisms that regulate this process are understood. Cardiomyocyte proliferation is under the control of a series of signal transduction pathways that connect extracellular cues to the activation of specific gene transcriptional programmes, eventually leading to the activation of the cell cycle. Both coding and non-coding RNAs  are involved in this regulation. The available information can be exploited for therapeutic purposes, provided that a series of conceptual and technical barriers are overcome. A major obstacle remains the delivery of pro-regenerative factors specifically to the heart. Improvements in the design of AAV vectors to enhance their cardiotropism and efficacy or, alternatively, the development of non-viral methods for nucleic acid delivery in cardiomyocytes are among the challenges ahead to progress cardiac regenerative therapies towards clinical application.  •Cardiac regeneration through the reprogramming of the endogenous cardiomyocyte proliferation potential is an attainable goal•Cardiomyocyte proliferation is controlled by extracellular cues through at least four signal transduction pathways•Administration of both protein coding genes and non coding RNAs can stimulate cardiomyocyte proliferation•Significant advances are needed to deliver the pro-proliferative nucleic acids to the heart using viral on non viral vectors This condition now affects 8.52 per 1000 individuals from the general population . Heart f14C‑carbon dating, to be less than 50% renewal in a 70-year lifetime [This sudden or progressive loss of cells is not accompanied by significant new cardiomyocyte generation after birth. The regenerative capacity of the normal adult human heart was estimated, through lifetime . This eslifetime  or usinglifetime ,16, mammThe repair of damaged hearts thus remains a holy grail in clinical medicine. One appealing possibility to achieve cardiac regeneration is to stimulate the proliferation of endogenous cardiomyocytes, as opposed to the implantation of cardiac progenitor cells  or diffe21)Regulators of the cardiomyocyte cell cycle.Over the last few years, a number of molecules and pathways have been reported to regulate cardiomyocyte proliferation acting both inside and outside the cells. The molecules acting intracellularly include cell cycle and metabolic regulators, microRNAs and activators of at least 4 different signalling pathways. The extracellular cues include factors acting from the extracellular matrix to the cardiomyocyte sarcolemma and a few cytokines. These are visually summarised in The arrest of cardiomyocyte proliferation after birth is contextual to the downregulation of essential cell cycle factors and the upregulation of cell cycle inhibitors. Cell cycle activators, such as cyclins, cyclin-dependent kinases (CDKs), c-Myc oncogene and E2F transcription factors are repressed ,21,22, wE-CDK2 complexes phosphorylate and inactivate the E2F repressor Rb. E2F factors also control the transcription of their own genes and the G1/S-phase Cyclin E, resulting in a positive cross-regulation. As an upstream regulator of Cyclin E and Cyclin A, overexpression of E2F1 in the heart stimulates DNA synthesis but results in an increased rate of cell death [Similar to other replicating cells in the body, most of the regulation of cardiomyocyte proliferation is exerted in the G1 phase of the cell cycle . In earlll death ,30, whilll death . In a coll death .Fig. 2MoE-CDK2 complexes are responsible for the initiation of the S phase. Cardiomyocyte-restricted Cyclin D1 overexpression increases DNA synthesis without progression through cytokinesis, resulting in augmented multinucleation [By triggering progression through the G1 restriction point, Cyclin D-CDK4/CDK6 and Cyclin cleation ,34 wherecleation  and reducleation . Cyclin cleation  and pig cleation  infarctscleation .S phase progression is assisted by the Cyclin A-CDK2 complex, which stimulates chromosome duplication and helps in controlling early mitotic events. Moreover, Cyclin A, this time in concert with CDK1, stimulates the entry in mitosis at the G2/M checkpoint; the Cyclin B-CDK1 complex also has a similar role. Cardiomyocyte-restricted overexpression of Cyclin A2 induces mitosis both in non-injured  and infaCyclin-dependent kinase activities are modulated by interactions with Cyclins and Cyclin-dependent kinase inhibitors (CKIs). Mice knock out for the p21 or p27 CKIs show failure in cell cycle exit at G1-phase and endoreduplication without successful cell division . AAV9-meMeis1, which belongs to the TALE (three amino acid loop extension) family of homeodomain transcription factors, is one of the central regulators of cardiac differentiation. Its expression increases postnatally in the heart where it activates transcription of p15, p16 and p21, which in turn switch off CDK6, 4 and 2 and arrest the cell cycle. Conditional knockout mice for Meis1 show extended postnatal proliferation and reactivation of mitosis in the adult heart, whereas overexpression of Meis1 impairs neonatal cardiomyocyte proliferation and regeneration . CardiomAnother transcription factor that interferes with the same cell cycle regulatory pathways is Tbx20, which is essential for cardiomyocyte proliferation during embryonic development. Overexpression of Tbx20 in adult cardiomyocytes promotes proliferation  due to tTogether, the above-mentioned studies provide proof-of-principle evidence that the cardiomyocyte cell cycle can be stimulated by the exogenous administration of positive cell cycle regulators, or the inhibition of those that exert a negative role. However, the impact of such treatments only seems to arise in a very small percentage of cells. This likely implies that a single regulator is not sufficient and that multiple pathways must be turned on to breach the diverse walls that block cardiomyocyte cell division. An attempt at multifactorial targeting was made through a combinatorial screening of the most differentially expressed cell cycle regulators between embryonic and adult mouse hearts, followed by the administration of a cocktail of four factors (Cyclin D-CDK4 and Cyclin B-CDK1) after myocardial infarction in mice . The resWhether all cardiomyocytes can re-enter the cell cycle or only a subset of cardiac cells participates in the regenerative process is still unclear. Single nucleus RNA sequence analysis indicates that only a specific subgroup of cardiomyocytes becomes proliferative after myocardial injury in neonate mice, which disappears as the heart loses the ability to regenerate . ConsistAn important problem in the field is to understand the molecular pathways that regulate entry into the S-phase, nuclear division and cell cytokinesis, as the three processes appear to be loosely correlated given that cardiomyocytes are often polypoid and/or multinucleated. Rodents are born with almost all cardiomyocytes that are mononucleated and diploid . By the In humans, the extent of multinucleation is much lower (around 10–25%) and is established during the first year of life , as most2)Signal transduction pathways that regulate cardiomyocyte proliferation.The mechanisms that drive polyploidy in favour of binucleation in cardiomyocytes from different species remain unclear. Both processes appear to occur as a response to different cellular stressors, as further discussed below. Similarities with other cell types, such as hepatocytes and keratinocytes, suggest that multinucleation and polyploidization could be ways to increase longevity and tolerance to genomic stress and apoptosis, as well as to sustain high levels of mRNA and protein synthesis . More spThe cardiomyocyte cell cycle is regulated by a variety of different signalling pathways, most of which are involved in heart development. Interest for these regulatory mechanisms focuses on both understanding the biology of cardiomyogenesis and exploiting this knowledge to stimulate regeneration. There are at least four signal transduction pathways that are involved in the regulation of cardiomyocyte proliferation - the Hippo, Wnt/β-catenin, Notch and PI3K/AKT pathways .Fig. 3MaThe Hippo pathway plays a pivotal role in the regulation of several organ size and growth, controlling cell proliferation, apoptosis and differentiation. Activation of this pathway by a protein kinase cascade leads to the phosphorylation and inactivation of the transcriptional coactivator YAP (Yes-associated protein). In its active form, YAP translocates into the nucleus where it associates with the transcriptional enhanced associate domain (TEAD) 1–4 transcription factors to drive gene expression and eventually stimulate cell proliferation. Deletion of YAP during development results in myocardial hypoplasia and early embryonic lethality ,64. TranNotch signalling controls cell fate specification and mesodermal commitment during development, regulating genes involved in proliferation, stem cell renewal, differentiation and apoptosis. In particular, Notch sustains the proliferation of immature cardiomyocytes during foetal and post-natal life . AlthougThe Wnt/β-catenin pathway not only is important for second heart field development , but als3)Regulation of cardiomyocyte proliferation by microRNAs.Finally, the PI-3-Kinase (PI3K)/AKT pathway is crucial to promote the growth and survival of several cell types, including cardiomyocytes. AKT inactivates pro-apoptotic proteins, activates Cyclin D1 and CDK2, inhibits p27 and regulates cell growth through mTOR activity (reviewed in ref. ). AKT caSeveral microRNAs (miRNAs) that tune cardiomyocyte proliferation have been identified by both transcriptional profiling in pre- and post-natal hearts  and highOther miRNAs act in an opposite manner by inhibiting cardiomyocyte proliferation. The role of miR-195 was unveiled by microarray analysis of RNA from ventricular samples from P1 and P10 mice . miR-1954)Extracellular cues that regulate cardiomyocyte proliferation.Collectively, these studies reinforce the possibility of achieving cardiac regeneration by the exogenous activation of the cell cycle through the modulation of microRNA levels. From a translational perspective, miRNA mimics or inhibitors are appealing because of their transient action, simple chemistry and low cost.The above-described mechanisms that control cardiomyocyte replication by signal transduction pathways and cell cycle regulators act inside the cells but are under the control of a few extracellular cues, by which cardiomyocyte replication is regulated by events occurring in the outside environment. Deciphering how this extracellular regulation links to the intracellular pathways is crucial for both understanding why cardiomyocyte replication stops at birth and developing regenerative therapies. A few of the extracellular cues that impact on cardiomyocyte replication are discussed here.2.1The newly born heart faces a sudden increase in circulatory demand due to sustained systemic blood flow, increased blood pressure and augmented ventricular afterload. This leads to ventricular wall stress, against which the postnatal heart reacts with an extensive structural remodelling of cytoskeleton and sarcomere, by increasing both the number of fibres and contractile units and switching on the expression of some components from the foetal to the adult isoforms (reviewed in ref. ). The mo2.2During development, mammals are exposed to relatively low oxygen tension. With birth, the heart experiences a sudden increase in oxygen level due to pulmonary respiration and shunt closure. In parallel, the postnatal metabolism adapts to this context and the growing energy demand by switching from lactate anaerobic glycolysis to fatty acid oxidative phosphorylation, which ensures a more efficient production of ATP. Together, these mechanisms cause increased mitochondrial biogenesis, accumulation of reactive oxygen species (ROS) and induced oxidative stress . The str2.3An emerging area of investigation links specific metabolic pathways to the control of cell proliferation, including in cardiomyocytes. Neonatal mice fed with fatty-acid-deficient milk, to revert metabolic substrates to those in the foetal environment, show prolongation of the postnatal cardiomyocyte proliferative window . Along tThe link between the activation of certain metabolic pathways and cell cycle regulation is well established in cancer cells. In particular, the muscle pyruvate kinase isoenzyme 2 (PKM2) interacts with β-catenin to enhance the activation of its downstream targets, which include c-Myc and Cyclin D1. In addition, PKM2 redirects glucose carbon flow into the pentose phosphate pathway resulting in less oxidative DNA damage ,116. PKMDuring ischemia, the citric acid cycle intermediate succinate accumulates from reversal of succinate dehydrogenase, which in turn is driven by fumarate overflow from purine nucleotide breakdown and partial reversal of the malate/aspartate shuttle. After reperfusion, the accumulated succinate is rapidly re-oxidized by succinate dehydrogenase (SDH), driving extensive ROS generation by reverse electron transport at mitochondrial complex I . In canc2.4The extracellular matrix (ECM) is a fundamental component of cardiac tissue and defines the mechano-physical properties of the cardiomyocyte extracellular milieu, as well as regulates the distribution and activation of secreted growth factors. Culturing neonatal rat cardiomyocytes on a soft matrix promotes dedifferentiation, myofibrillar disassembly and increased cell division, whereas a rigid matrix facilitates differentiation, cell cycle arrest and binucleation, with stiffness specifically affecting cardiomyocyte cytokinesis . In mice2.5While a large body of information now exists on the mechanisms that regulate cardiomyocyte proliferation, translation of this information into the clinic remains challenging. This is also indirectly indicated by the relative paucity of studies that have progressed towards proving cardiac regeneration in large animals, compared to those in cells and rodents . Two mai2.6One of the overarching problems in cardiac regeneration is how to find a master gene or gene cocktail that stimulates effective endogenous cardiomyocyte proliferation. It is becoming progressively clear that new cardiomyocyte formation is more complex than the regulation of cell division, and that cardiac regeneration is more complex than the formation of new cardiomyocytes. Compared to other tissues, adult cardiac fibres are formed of spatially and functionally arranged cardiomyocytes that are electrically and mechanically interconnected, with a highly hypertrophic cytoplasm enlarged in the transition from birth and adulthood to sustain increased organ mass, and containing a massive number of spatially arranged sarcomeric units and of active mitochondria. As discussed above, the physiological division of cardiomyocytes must cope with this complexity, and it does so not without molecular and spatial problems also in physiological conditions, if one has to judge from the level of polyploidy and multinucleation that most likely ensues from the problem of completing mitosis and cytokinesis respectively. In addition, the epigenetic structure of cardiomyocytes has a defined arrangement, in which several genes expressed during development are silenced by compacted chromatin conformation and cytosine methylation ,28,129.Stimulating the replication of cardiomyocytes requires overcoming all these layers of complexity, hence the need of “reprogramming” these cells towards a regenerative state rather than, more simply, stimulating their replication. The more effective treatments appear those that mimic the physiological signals  that stimulate spontaneous regeneration in the neonatal mammalian heart or in the fish and amphibian hearts throughout life, or the treatments that lead to marked cell de-differentiation, such as the administration of transcription factor cocktails that transiently reprogram the cells towards an embryonic phenotype . Of noteHow can we find such master regulators of complex new cardiomyocyte generation? It is possible that the identification of such genes could come through the investigation of specific pathways , but most likely they should be sought by ex vivo and in vivo screenings for cardiomyocyte replication using genomic and ncRNA libraries with high complexity. Of note, such broad screenings have the potential to identify new factors with therapeutic function irrespective of their natural involvement in the physiological process of cardiomyocyte replication during development or in other species. In terms of activating a complex biological programme, microRNAs are of particular interest, as each of these molecules can target tens or hundreds of different cellular mRNAs. For instance, for cardiomyocyte proliferation to occur, there is a need for disassembling the sarcomere, reactivating the expression of cell cycle proteins, and reforming the centrosomes, all of which are require modulation of several different genes .2.7cap gene [14 vector genomes per kg. This high dose can end up in inflammation and both innate and acquired immunity activation [A master problem that has affected gene therapy since its early days, and still hampers its development, is how to deliver nucleic acids efficiently into the cells and in vivo . Some nacap gene . Despitetivation . This istivation .Delivery of nucleic acids using non-viral systems has advanced significantly over the last couple of decades, with a few nanoparticles that have reached clinical trials. Non-viral delivery of mRNA is currently experiencing a period of excitement after the development of lipid nanoparticles (LNPs) formed using the Stable Nucleic Acid Lipid Particle (SNALP) technology . This teProgress in at least three areas related to nucleic acid administration would bring the cardiac gene therapy field forward, including applications for endogenous cardiac regeneration. First, the efficiency of viral vectors needs to be improved. The gold standard remains AAV vectors, but, as noted above, the efficiency of these vectors depends on the administration of large amounts of viral particles. This is required to overcome a series of stumbling blocks in the AAV vector life cycle, most notably virion trapping in unproductive endosomal routes, exit from endosomal vesicles and transport to the nucleus, and escape from the cellular DNA damage response machinery that limits conversion of single-stranded vector genome into transcription-proficient double-stranded DNA (reviewed in ref. ). All thA second long-sought improvement, which still relates to viral vectors, is the development of pharmacologically inducible promoters for controlled transgene expression. The current generation of viral vectors does not permit transcriptional regulation. This can be acceptable for applications in heart failure, in which chronic production of a therapeutic protein or ncRNA might be beneficial, but not for applications aimed to induce cardiomyocyte proliferation. Our own study with an AAV vector constitutively expressing the pro-regenerative miR-199a microRNA shows that the cardiac remuscularization that occurs in the first month from administration can be followed by hyperproliferation and the generation of fatal arrhythmias when transgene expression is not controlled . SimilarN-acetylgalactosamine  trimers, which bind the cellular asialoglycoprotein receptor [A third holy grail of nucleic acid-based therapies for the heart is cell specific targeting. This applies to both viral and non-viral methods for gene transfer. The most efficient method for in vivo targeting is epitomized by targeting hepatocytes using receptor . Both onreceptor , GalNac receptor ). HoweveIn the absence of targeting, an approachable way forward for heart specific delivery is through catheter-mediated administration. Intramyocardial injections can be performed through a mini thoracotomy or during coronary bypass surgery, followed by trans-epicardial delivery. Less invasively, an intramyocardial injection can follow percutaneous intraventricular catheterisation by trans-endocardial delivery. Several catheters are already available for human application (reviewed in ref. ), often 3Cardiac regeneration through the stimulation of the cardiomyocyte endogenous proliferative potential is a realistically attainable goal, provided that a series of conceptual and technical barriers are overcome. The possibility of exploiting the potential of both coding and non-coding RNAs and the development of highly processive methods for their functional screening can provide master treatments that reprogramme cardiomyocytes towards a replicative state. A major barrier remains the delivery of these regenerative nucleic acids specifically to the heart. Improvements in the design of AAV vectors, with the inclusion of pharmacologically inducible promoters, cell manipulation to transiently improve permissivity to these vectors or, alternatively, the development of non-viral methods for nucleic acid delivery that are specifically targeted to the heart are among the challenges ahead to render cardiac regenerative therapies closer to clinical application.


Background and Objectives: One’s quality of life depends on overall health, and in particular, oral health, which has been and continues to become a public health issue through frequent manifestations in various forms, from simple oral stomatitis  to the complicated oral health pathologies requiring medical interventions and treatments . The aim of this study focused on the preparation and evaluation of vitamins  incorporated into several silicone-based lining materials as a new alternative to therapeutically loaded materials designed as oral cavity lining materials in prosthodontics. Materials and Methods: Silicone-based liners containing vitamins were prepared by mixing them in solution and becoming crosslinked, and then they were characterized using Fourier-transform infrared (FT-IR) spectroscopy to confirm the incorporation of the vitamins into the silicone network; scanning electron microscopy (SEM) to evidence the morphology of the liner materials; dynamic vapor sorption (DVS) to evaluate their internal hydrophobicity, swelling in environments similar to biological fluids and mechanical test to demonstrate tensile strength; MTT to confirm their biocompatibility on normal cell cultures (fibroblast) and mucoadhesivity; and histopathological tests on porcine oral mucosa to highlight their potential utility as soft lining materials with improved efficiency. Results: FT-IR analysis confirmed the structural peculiarities of the prepared lining materials and the successful incorporation of vitamins into the silicone matrix. The surface roughness of the materials was lower than 0.2 μm, while in cross-section, the lining materials showed a compact morphology. It was found that the presence of vitamins induced a decrease in the main mechanical parameters  and hydrophobicity, which varied from one vitamin to another. A swelling degree higher than 8% was found in PBS 6.8  and water. Hydrolytic stability studies in an artificial saliva medium showed the release of low concentrations of silicone and vitamin fragments in the first 24 h, which increased the swelling behavior of the materials, diffusion and solubility of the vitamins. The microscopic images of fibroblast cells incubated with vitamin liners revealed very good biocompatibility. Also, the silicone liners incorporating the vitamins showed good mucoadhesive properties. The appearance of some pathological disorders with autolysis processes was more pronounced in the case of vitamin A liners. Conclusions: The addition of the vitamins was shown to have a beneficial effect that was mainly manifested as increased biocompatibility, hydrolytic stability and mucoadhesiveness with the mucosa of the oral cavity and less of an effect on the mechanical strength. The obtained lining materials showed good resistance in simulated biological media but caused a pronounced autolysis phenomenon, as revealed by histopathological examination, showing that these materials may have broad implications in the treatment of oral diseases. Often, different types of lesions can occur in the oral mucosa while making an impression or extracting teeth from the oral cavity. Other injuries are due to patients’ pre-existing natural oral pathologies and mucosal diseases, which are not injuries caused by medical procedures or techniques. Like any procedure that aims to replace or bring new biomaterials into contact with oral tissues, the process of oral prosthetics represents a trauma to the patient. Regardless of the source of the lesion, all patients undergoing prosthetics need a rapid healing time of the oral tissues, not only for the success of the procedure but also for the overall well-being of the oral mucosa. The use of soft restorative materials can eliminate the risks associated with prosthetic injuries but cannot heal pre-existing ones .2, but easy access to this site makes it a preferred site for drug administration. This site provides an opportunity to systemically deliver pharmacologically active agents by avoiding first-pass hepatic metabolism, in addition to the local treatment of pre-existing oral lesions, such as ulcerations, gingivitis, periodontal diseases or those produced during dental medical interventions .,22.21,222 for 2 h, and then the MTT solution was removed and the formed formazan crystals were solubilized with DMSO. The absorbance of the resulting formazan solution (blue-violet) was measured at λ = 570 nm using a plate reader . The assay was performed at 24, 48 and 120 h.The cells with the MTT solution were incubated at 37 °C in 5% COAbs material) were compared with the control wells (Abs control) in which no film aliquots were present, resulting in the cell viability values V (%) (Equation(5)):The results from the experimental wells  by using a synthetic open-pore cellulose membrane obtained via boiling and step-cooling and a biologic mucosal tissue of porcine oral tissue. Prior to testing, all silicone lining materials were cut to a standard size (pieces of 4 cm2). For measurements, PBS pH 7.4 and artificial saliva (pH 6.8) were used to mimic physiological body conditions.Experiments were performed within the predefined software experimental settings: a holding instrument speed of 1 mm/s to reach the synthetic and biological mucosa, a contact force of 9.8 mN, and a contact time between the lining materials and biological mucosa or cellulose membrane of 30 s. The results obtained as detachment force and work of adhesion parameters were automatically calculated using TA.XT Plus® texture equipment Exponent Connect software. The results from triplicate measurements were plotted with standard deviation.Histological analysis was performed on harvested oral mucosal biopsies, which were first fixed in 10% buffered formalin solution for 24 h, then sections were placed in hematoxylin for 2 min and in 0.5% ammonia for 1 min, and then washed and placed in eosin for 2 min using Thermo Scientific Microm HMS 70. The dehydration, cleaning, capping and paraffin embedding procedures were performed using a 120-3 Thermo Scientific STP tissue processor. Biopsy fragments were examined using an Olympus BX 41 microscope  coupled with an Olympus DP25 video camera.−1, respectively. The stretching vibrations from 2962 to 2830 cm−1 are characteristic of asymmetric and symmetric stretching vibrations of C-H groups attached to silicon atoms. The corresponding deformations of these groups occurred at 1258 cm−1, while the rocking vibrations of Si-CH3 groups occurred at 789 cm−1  caused a higher degree of swelling of the reference lining material and vitamin B6 liner (6%), with lower values being found for the vitamin A liner and the vitamin B1 liner (4%), but higher values in water, than the other two, similar to other literature reports . The cheAfter 72 h, all lining materials showed a swelling degree greater than 8% in PBS 6.8 and water, followed by equilibration at a longer time.The stability of silicone-based lining materials was studied in PBS 7.4 and artificial saliva (PBS 6.8) for 72 h because, as shown in the swelling data, these materials sustained different degrees of swelling and it is important to determine whether these media can cause hydrolysis by-products. Using the IR subtracting procedure, the main spectral changes can be observed after immersion in these media. Thus, the studied IR difference spectra between the initial spectra and those that resulted after immersion for 24 h, 48 h and 72 h are shown in The analysis of the hydrolytic stability in artificial saliva medium revealed a similar behavior to in the PBS 7.4 medium, with the release of small silicone fragments in all samples being more pronounced for the reference and vitamin A liner a,b, whilThe results of the cytotoxicity assay are shown in Microscopic images  of fibroThe vitamin B1 silicone dental lining material tested using MTT showed high cell viability and good biocompatibility for all incubation periods (24 to 120 h), highlighting that it is safe for clinical use. The tested liner materials showed a higher adhesion force on the oral mucosa tissue, especially for the vitamin-based materials . The samExamination of the mucosa before and after exposure to vitamin-containing silicone liners indicated auto-inflammatory processes, especially by treatment with vitamin A liner, as can be seen in The use of dental soft lining materials and silicone-based gels has often shown itself to be a good alternative to acrylic-based materials. Silicones are biocompatible and have good resistance to variable conditions, good shape and color stability , and canIn this study, we aimed to improve the effectiveness of silicone-based lining materials by incorporation of the vitamins A, B1 and B6, which are involved in caries and periodontitis prevention and oral health. In general, there is little evidence to support the relation between vitamins and both gingival/periodontal disease and dental hard pathological processes, despite current literature suggesting that vitamins are helpful in the prevention and treatment of oral diseases. Future research on the effects of vitamins on the mouth, as well as specific studies of complex biological mechanisms, would have wider applications in dentistry and medicine .−1 spectral range; 1258 and 789 cm−1 were specific to the Si-O-Si and Si-CH3 groups, respectively; and the specific absorptions of the vitamins were identified in the 1800–1300 cm−1 spectral range  were for the first time encapsulated in soft Mollosil dental lining materials to improve their biocompatibility and mucoadhesiveness for better tolerance of prosthetic devices. The new composition of the resulting lining materials was analyzed using IR spectroscopy, highlighting the interaction of vitamins with the silicone matrix. The addition of vitamins was found to have a beneficial effect that was mainly manifested as improved biocompatibility, hydrolytic stability and mucoadhesiveness with the oral mucosa, and less as mechanical strength. The obtained lining materials showed good resistance in simulated biological environments but caused a pronounced autolysis phenomenon, as revealed by histopathological examination, supporting the fact that these materials have far-reaching implications in the treatment of oral diseases.


CHD3 (Chromodomain Helicase DNA Binding Protein 3), which seems to be involved in chromatin remodeling by deacetylating histones. Here, we report 20 additional patients with clinical features compatible with SNIBCPS from 17 unrelated families with confirmed likely pathogenic/pathogenic variants in CHD3. Patients were analyzed by whole exome sequencing and segregation studies were performed by Sanger sequencing. Patients in this study showed different pathogenic variants affecting several functional domains of the protein. Additionally, none of the variants described here were reported in control population databases, and most computational predictors suggest that they are deleterious. The most common clinical features of the whole cohort of patients are global developmental delay (98%) and speech disorder/delay (92%). Other frequent features (51–74%) include intellectual disability, hypotonia, hypertelorism, abnormality of vision, macrocephaly and prominent forehead, among others. This study expands the number of individuals with confirmed SNIBCPS due to pathogenic or likely pathogenic variants in CHD3. Furthermore, we add evidence of the importance of the application of massive parallel sequencing for NDD patients for whom the clinical diagnosis might be challenging and where deep phenotyping is extremely useful to accurately manage and follow up the patients.Snijders Blok–Campeau syndrome  is an extremely infrequent disease with only approximately 60 cases reported so far. SNIBCPS belongs to the group of neurodevelopmental disorders (NDDs). Clinical features of patients with SNIBCPS include global developmental delay, intellectual disability, speech and language difficulties and behavioral disorders like autism spectrum disorder. In addition, patients with SNIBCPS exhibit typical dysmorphic features including macrocephaly, hypertelorism, sparse eyebrows, broad forehead, prominent nose and pointed chin. The severity of the neurological effects as well as the presence of other features is variable among subjects. SNIBCPS is caused likely by pathogenic and pathogenic variants in  CHD3) gene. The disorder shows an autosomal dominant pattern of inheritance. The most common clinical findings in affected patients include a neurodevelopmental disorder, characterized by global or speech delay, followed by either intellectual disability (ID) or specific learning difficulties, behavioral disorders like autism spectrum disorder (ASD) or attention deficit hyperactivity disorder (ADHD), and dysmorphic features including macrocephaly, prominent forehead, hypertelorism, face asymmetry, deeply set eyes, strabismus, epicanthus, wide nasal bridge, prominent nose, pointed chin, high palate and joint laxity among others [CHD3 gene [CHD3 gene, and one patient was found to have a large duplication of the CHD3 gene [Snijders Blok–Campeau syndrome (SNIBCPS) MIM #618205) is a notably infrequent autosomal dominant disease, first described by Snijders Blok et al. in 2018 [8205 is aHD3 gene ,5,6. TheCHD3 encodes for a protein involved in late neural radial migration and cortical layer specification [Mammalian chromodomains helicase DNA-binding (CHDs) comprises a large family of proteins that have an indispensable role in developmental processes. Specifically, these proteins are involved in transcriptional regulation, and they can exert their chromatin remodeling activity to form the core ATPase subunit of the complex Nucleosome Remodeling Deacetylase (NuRD), which is associated with multiple cellular processes such as genomic integrity, cell cycle progression, or embryonic stem cell differentiation. Specifically, fication . All thefication   and highlights the importance of an early diagnosis and the implementation of massive parallel sequencing technologies such as whole exome sequencing as the first tier for the diagnosis of these highly heterogeneous disorders.Here, we describe 20 additional patients from 17 unrelated families with confirmed novel pathogenic variants in CHD3 from laboratories and hospitals in Spain, India, Italy and France. Informed consent was obtained from all patients and/or their legal guardians. Neuropsychiatric findings were evaluated by a specialist for each patient. Some of the patients from Hospital Universitario La Paz are part of the Spanish Overgrowth Registry Initiative (SOGRI) database.All patients were recruited based upon either their clinical findings or the molecular defect in Patients were mostly analyzed by whole exome sequencing (WES). Segregation analysis was performed in parental samples by Sanger sequencing when samples were available. Variants are described using the HGVS nomenclature and classified according to the ACMG guidelines . The in CHD3. Segregation analysis showed that variants were de novo in 16 out of 20 patients (80%), inherited in 3 others (15%), and segregation analysis was not possible for one of them.By means of the application of massive parallel sequencing technologies, as well as international collaboration through scientific networks, we have identified 20 additional cases with SNIBCPS with pathogenic or likely pathogenic variants in At the clinical level, all 20 patients were phenotyped, and the identified clinical features are summarized in CHD3 gene. Both mother and daughter presented with initial global developmental delay but had no ID and a diagnosis of developmental coordination disorder. The son presented with ASD and moderate ID.In addition, in our cohort we present a family  observed were: intellectual disability, hypotonia, hypertelorism, abnormality of vision, macrocephaly and prominent forehead.At the molecular level, 16 out the 20 variants detected were missense and the other four included a nonsense, a frameshift deletion, and two in-frame deletions. All variants were heterozygous.The majority of the detected variants were located within or between the helicase ATP-binding domain, the helicase C-terminal domain and the DUF domain except for the frameshift variant, which is located before the C-terminal 2 domain and the transcript encoded is predicted to be degraded by the nonsense-mediated decay (NMD) mechanism .After ACMG variant classification, eight variants were classified as pathogenic and 12 as likely pathogenic. None of the variants reported herein were previously reported and/or associated with SNIBCPS. Moreover, none of the variants described in our series have previously been reported in pseudo-control population databases  and the majority of the computational evidence support a deleterious/pathogenic effect for all the variants reported in this study .NDDs comprise a large and highly heterogeneous group of disorders, caused by a variety of pathogenic and likely pathogenic variants in >1000 genes and in which there might by a highly clinical presentation overlap. With the advances in massive parallel sequencing technologies, it has become possible to identify and confirm or discard initial clinical suspicions in this group of patients.CHD3, it may have phenotypic overlap with other human diseases caused by mutations in CHD proteins. Some of these may include CHD7 causing CHARGE syndrome (MIM #214800), CHD4 as causative of Sifrim–Hitz–Weiss syndrome (MIM #603277), or CHD8 causing autism spectrum disorder (MIM #610528).SNIBCPS was first described in 2018 by Snijders Blok et al. [One of the challenges in the recognition of the SNIBCPS syndrome is the highly phenotypic overlap with other genetic disorders, especially NDDs and overgrowth syndromes, because the most common findings are macrocephaly and neurodevelopmental problems. Besides NDDs and enlarged head circumference, some dysmorphic features such as pointed chin or frontal bossing may resemble syndromes such as Sotos, Malan, Tenorio, or Simpson–Golabi–Behmel syndromes ,11,12,13CHD3 and CHD4, which are important for the activity of the NuRD complex, as they provide the energy and helicase function necessary for chromatin remodeling. This complex has important functions in cellular processes such as peripheral nerve myelination and cortical development in the brain. CHD3 is an ATP-dependent chromatin remodeling protein that serves as core member of the NuRD complex [NuRD is an ATP-dependent chromatin remodeling complex. It consists of multiple proteins, including  complex  and it h complex .CHD3 gene was identified. Thus, thanks to the increase in the number of patients with CHD3 defects, it was possible to expand the SNIBCPS phenotype.In this study, we report 20 patients from 17 unrelated families with a clinical phenotype compatible with SNIBCPS in whom a pathogenic/likely pathogenic variant in the Reviewing our cohort of patients, we observed that global developmental delay and speech disorder/delay are the most common (>75%) clinical features. The clinical characteristics observed in 50–75% of individuals were intellectual disability, hypotonia, hypertelorism, abnormality of vision, macrocephaly and prominent forehead. Less common clinical features (25–50%) were abnormality of CNS, autism and some dysmorphic features such as pointed chin or wide nasal bridge, among others . In addiCHD3 gene [We found 20 likely pathogenic/pathogenic variants. On the other hand, it has previously been reported that most of the variants described are located within the ATPase/helicase domain of the Of the 20 individuals in our cohort, eight of them had pathogenic variants in the ATPase/helicase domain, with 12 variants being outside this domain. It has previously been reported that there are no phenotypic differences between patients with variants within the ATPase/helicase domain and individuals with variants outside this domain [In our series, we also found no phenotypic differences between patients with a variant within the ATPase/helicase domain and those with a variant outside of this domain.CHD3 is extremely intolerant to LoF (loss-of-function) and missense variation based on in silico analysis . These values suggest that a haploinsufficiency mechanism may be the cause of the disease, as other studies have already suggested [uggested . We analCHD3 using an ATPase assay. A clear decrease in ATPase activity was observed in two variants (p.Arg1121Pro and p.Arg1172Gln) [CHD3  may affect critical functions of the protein, such as impacting the ability of the protein to interact with other molecules or proteins involved in chromatin remodeling processes. On the other hand, it can influence the stability and folding capacity of the protein to adopt its three-dimensional structure, leading to protein misfolding and/or instability. In order to fully understand the consequences of the different variants in CHD3, further functional analysis and protein modeling techniques are needed.In addition, previous studies have sought to determine the effect of variants in 1172Gln) . Our hypIn our series, segregation analysis showed that three of the patients had a variant inherited from one of their parents (15%). In one of these families, the transmitting parent was apparently healthy. It has been reported that most of the variants inherited in other cohorts were maternally inherited, suggesting that female gender protects against genetic variations in this disease. This observation may indicate incomplete penetrance and variable expressivity in this syndrome .CHD3 gene. The main clinical manifestations are the presence of neurodevelopmental problems without intellectual disability in half of the patients as well as dysmorphic features, such as macrocephaly. At the molecular level, we found in our cohort, as well as in the cohorts described above, that most of the variants are located in the ATPase/helicase functional domain. Thus, we have increased the number of patients with SNIBCPS as well as expanded the phenotypic features of this unusual disorder. Further studies may help to elucidate genotype–phenotype correlations and to understand the mechanism by which a CHD3 gene defect causes Snijders Blok–Campeau syndrome (OMIM #518205).In conclusion, we herein report 20 additional patients with novel variants along the


Alzheimer’s disease (AD) is one of the most prevalent age-related neurodegenerative diseases and accounts for the majority of dementia cases worldwide. Tremendous ongoing efforts of basic and clinical research have expanded our knowledge on AD and its complex multifactorial pathogenesis. For sporadic AD, it is widely assumed that silent and early symptomatic stages initiate decades before the irreversible decline in cognitive abilities that ultimately lead to debilitating conditions. In addition to amyloid plaques and tau-containing neurofibrillary tangles as the most prominent hallmarks of AD lesions within the affected brain areas, we now possess a broader collection of pathological signatures that are associated with AD development and progression. In this regard, there is a substantial body of evidence suggesting that hypometabolism occurs in the brains of individuals at the prodromal stage before dementia is diagnosed, which may reflect an early role of metabolic dysfunction in AD. This perspective surveys the vast literature and critically assesses the current evidence demonstrating a mitochondrial contribution to AD. Additionally, we discuss our interpretations of the reported mitochondrial signatures and consider how altered mitochondrial bioenergetics may be an additional risk factor for AD pathogenesis. Alzheimer’s disease (AD) is an idiopathic, non-communicable neurodegenerative disease with progressive behavioral changes and cognitive impairment, including severe memory decline as the most prominent deficit. As for other neurodegenerative conditions, one of the main features of AD is the long preclinical disease stage in which pathological changes occur in patients, although affected individuals initially do not exhibit striking cognitive symptoms and other clinical manifestations , 2. CompPSEN1 and PSEN2, respectively) or amyloid-precursor protein (APP) genes. Postmortem studies have reported that individuals affected by familial AD feature an abnormal accumulation of Aβ plaques, as well as other neuropathological lesions  commonly observed in idiopathic AD patients [AD is a complex multifactorial neurological disorder of old age, with a prevalence that dramatically increases in people age 65 years or older , 8. As tpatients –15. Thespatients , 17. Morpatients –21.Another characteristic feature of AD is the progressive decline of glucose metabolic rate in certain areas of the brain. In patients with early signs of mild cognitive impairment, multiple longitudinal studies indicate that brain hypometabolism may correlate with the development of tau deposition and atrophy of the temporal and parietal lobes –24. DespWith this perspective, we aim to assess the most convincing findings suggesting a mitochondrial involvement in AD pathogenesis.Mitochondria are intracellular double membrane organelles providing energy in the form of ATP as well as a variety of metabolic intermediates that are exported to the cytosol or transferred to other intracellular organelles . The conPITRM1 mutations develop progressive spinocerebellar ataxia and functional changes of mitochondrial bioenergetics in muscle biopsy. In transgenic mice, yeast and cultured cells, PITRM1 deficiency seems to negatively affect the ability of cells to degrade Aβ peptide [PITRM1 mutations confirmed low levels of Aβ1–42 in the cerebrospinal fluid (CSF) that are comparable to those in AD patients [Consistent with these pleiotropic functions, aberrant mitochondrial activities have been linked to several human disorders, including metabolic syndromes and neurodegenerative diseases. However, while the genetic link between mitochondria, inherited neuropathies and metabolic disorders is well-described and widely observed in clinical practice and experimental biology –42, a co peptide , 51. As  peptide , 52. Alt peptide –56, in-dpatients . Future ECHDC3, COX7C and NDUFAF6 genes encoding enoyl-CoA hydratase domain-containing protein 3, cytochrome c oxidase subunit 7C and NADH:ubiquinone oxidoreductase complex assembly factor 6, respectively [Over the past years, many genome-wide association studies (GWAS) have reported single nucleotide variants associated with a higher risk of late-onset AD. Some of these genetic variants are located near genes contributing to mitochondrial bioenergetics, such as ectively , 57, 58.ectively , 28, 44.Using positron emission tomography (PET), longitudinal assessments of patients with early AD have recently revealed progressive reduction of Complex I radioligand binding . These dUsing isobaric labeling for quantitative proteomics, it was shown that significant changes in Complex I subunits as well as a few additional components of other respiratory complexes can be detected in postmortem brain tissues  of AD patients compared to aged-matched non-demented women . As thesTaken together, these experimental data indicate a strong association between aberrant mitochondrial bioenergetics and AD, although its precise contribution to the development of the disease requires further mechanistic evidence.This perspective aims to survey the currently available data obtained from recent studies of subjects at risk of AD as well as postmortem assessments of tissues from healthy and cognitively impaired donors. We recognize the impressive advances in the field, despite the substantial limitations in current detection methods and the availability of properly collected postmortem samples. We cover studies of the last decade and report the most convincing data suggesting a correlation between the expression changes of mitochondrial components and the progressive age-related development of AD. On purpose, we did not review the abundant literature on transgenic mice and other in vivo and in vitro experimental models, from which we learnt how modulation of mitochondrial behaviors can influence several aspects of Aβ and tau pathology. Despite the uncertainty about the contribution of mitochondria in AD, we think that altered glucose and oxygen metabolism may develop first and become a prominent signature during the course of aging. Due to circulatory and/or other risk factors, the diminished supply of substrates would then undermine mitochondrial bioenergetics and lead to energy production defects, ROS generation, aberrant intracellular signaling and impaired mitochondrial biosynthetic activities. In such a pathological scenario, defective mitochondria would compromise even further the resilience mechanisms of neurons and neural circuitry that, in aging, could become more susceptible and vulnerable to injuries , 65–67.


In the last decades the prevalence of obesity has increased dramatically, and the worldwide epidemic of obesity and related metabolic diseases has contributed to an increased interest for the adipose tissue (AT), the primary site for storage of lipids, as a metabolically dynamic and endocrine organ. Subcutaneous AT is the depot with the largest capacity to store excess energy and when its limit for storage is reached hypertrophic obesity, local inflammation, insulin resistance and ultimately type 2 diabetes (T2D) will develop. Hypertrophic AT is also associated with a dysfunctional adipogenesis, depending on the inability to recruit and differentiate new mature adipose cells. Lately, cellular senescence (CS), an aging mechanism defined as an irreversible growth arrest that occurs in response to various cellular stressors, such as telomere shortening, DNA damage and oxidative stress, has gained a lot of attention as a regulator of metabolic tissues and aging-associated conditions. The abundance of senescent cells increases not only with aging but also in hypertrophic obesity independent of age. Senescent AT is characterized by dysfunctional cells, increased inflammation, decreased insulin sensitivity and lipid storage. AT resident cells, such as progenitor cells (APC), non-proliferating mature cells and microvascular endothelial cells are affected with an increased senescence burden. Dysfunctional APC have both an impaired adipogenic and proliferative capacity. Interestingly, human mature adipose cells from obese hyperinsulinemic individuals have been shown to re-enter the cell cycle and senesce, which indicates an increased endoreplication. CS was also found to be more pronounced in mature cells from T2D individuals, compared to matched non-diabetic individuals, with decreased insulin sensitivity and adipogenic capacity.Factors associated with cellular senescence in human adipose tissue Due to the worldwide epidemic of obesity and type 2 diabetes (T2D), the adipose tissue (AT) biology and physiology has received increased attention. Nowadays, AT has gone from being only considered as a fat storing tissue to a highly active metabolic and endocrine organ with impact on the whole-body  is induced as a stress response and defined as an irreversible cell cycle arrest with antitumorigenic effects. Senescent cells cease to proliferate but are still metabolic active and they adopt specific characteristics, with increased cellular growth and secretion of various factor called the senescence-associated secretory phenotype (SASP). Senescent cells have also impact on several other processes, such as wound healing, fibrosis and aging. Lately, CS has also gained a lot of attention due to its involvement in the development and progression of metabolic disorders, such as obesity and T2D .AT is distributed throughout the whole body and divided into the main adipose depots, subcutaneous AT (SAT), located under the skin, and visceral AT (VAT), within the abdominal wall and surrounding the internal organs , microvascular endothelia cells (MVEC), and different immune cells. Even though mature adipose cells only account for 20–40% of AT resident cells they occupy more or less the whole tissue  and hyperplasia (recruitment and differentiation of APC). Mature adipose cell growth per se is a necessary mechanism to be able to accommodate excess nutrients and store as triglycerides. SAT is the depot that has the largest capacity to store lipids and, if needed, recruiting new APC will protect against metabolic disease by preventing hypertrophic expansion , solute carrier family 2 member 4 , and adiponectin, which suggests an impaired adipogenesis  signaling pathways, which have negative impacts on insulin signaling as well as increased expression of several proinflammatory genes. This also increases the infiltration and activation of inflammatory macrophages, known to produce and secrete chemokines and proinflammatory cytokines, such as interleukin 6 (IL6) and tumor necrosis factor-α (TNFα), where both have been shown to directly inhibit insulin signaling , a key trigger of global chromatin reconfiguration, as well as chromatin reorganization  ) and/or retinoblastoma (RB) tumor suppressor pathways play a central role, which leads to the accumulation of the cyclin dependent kinase (CDK) 2 inhibitor p21 (encoded by cyclin dependent kinase inhibitor (CDKN) 1A) and CDK4/6 inhibitor p16 (encoded by CDKN2A). As a consequence of this, RB will be activated and result in a persistent cell-cycle arrest , and CVD  compared to lean individuals  and serpin family E member 1 (SERPINE1), were increased in hypertrophic obesity and further increased in similarly obese T2D individuals. For APC to enter the adipogenic program p53 must be downregulated, which turned out to be impaired in human senescent APC, as discussed above  as one of the top-ranked genes  were increased in mature adipose cells from obese hyperinsulinemic individuals , p53 and the phosphorylation of mitogen-activated protein kinase 8  were increased in mature adipose cells, which corresponded to decreased levels of adipogenic markers, PPARγ and GLUT4, and insulin sensitivity measured as serine 473 phosphorylation of AKT in T2D compared to lean individuals , an important regulator of cell cycle progression, was detected in obese individuals with hyperinsulinemia  are decreased as markers of de-differentiation of the cells  can remain quiescent for years but, when needed, they become activated and initiate new vessel formation (angiogenesis), which is essential for the function of mature adipose cells as well as adipogenesis  (Briot et al. Interestingly, it was found that VAT-derived MVEC from obese individuals had a more pronounced senescent phenotype than SAT-derived MVEC together with a decreased expression of PPARγ (Villaret et al. Senescent cells have left the cell cycle and become proinflammatory through secretion of SASP factors which include cytokines, chemokines, miRNA, DNA and other factors which can target ambient cells and induce senescence in these as well. Like many other cells, adipose tissue cells; both progenitor cells, mature adipose cells and microvascular endothelial cells, undergo senescence with aging but it is also increased with other common conditions like obesity and T2D. We only know some factors which can contribute to this including genetic factors and development of hyperinsulinemia. Adipose tissue cell senescence is associated with reduced adipogenesis, impaired adipose cell function, reduced PPARγ and reduced insulin sensitivity. Treating cell senescence in animal models improve many aging-associated conditions including insulin resistance, hyperglycemia and cardiovascular conditions. The current development of senomorphic agents may allow treatment of common aging-associated conditions in man as well but firm proof of this is currently not yet available.


Selecting a suitable and preferable method for endometrial preparation in frozen embryo transfer (FET) cycles for women with adenomyosis is still challenging in infertility treatment.To compare 2 artificial endometrial preparation regimens with and without gonadotropin-releasing hormone agonist (GnRHa) pretreatment in women with adenomyosis undergoing FET cycles.This randomized clinical trial study was conducted on 140 adenomyosis cases who underwent FET cycles at Arash Women's hospital, Tehran, Iran from May 2020 to March 2021. Participants were randomly allocated into hormonal replacement therapy (HRT) and HRT+GnRHa pretreatment groups (n = 70/each). Endometrial preparation with 2-6 mg daily estradiol was started in the HRT+GnRHa group, taking after down-regulation with the GnRHa. Within the HRT group, the same dose of estradiol was commenced within the early follicular stage. The main  and auxiliary results  were compared between groups.The demographic characteristics and severity of adenomyosis, endometrial thickness, and pattern at starting progesterone administration were similar in the 2 groups, and triple-line endometrium was found to be the dominant pattern in both groups (p = 0.65). No significant differences were observed in chemical, clinical, and twin pregnancy rates as well as miscarriage and live birth rates between groups . However, the total estrogen dose and duration of estrogen consumption were significantly higher in the pretreatment group . These results indicated that the hormonal endometrial preparation with estrogen and progestin for FET cycles is as efficacious as a protocol involving preceding pituitary suppression with a GnRHa. Further large randomized clinical studies are required to confirm these findings. Adenomyosis is a benign disease of the uterus defined by the growth of the basal endometrium into the sub-endometrial myometrium (1). Due to postponing pregnancy until the third decade of a woman's life, it is much more recognized among infertile cases who underwent assisted reproductive technology (2). Adenomyosis manifests with dysmenorrhea, menorrhagia, pelvic pain, and an enlarged and tender uterus (3). The conceivable etiology is recommended as disturbance of the typical boundary between the endometrium and the myometrium during physiological recovery and mending of the endometrium, driving to myometrial intrusion by endometrium (4). Endometrial healing activates the immune system, resulting in increased estrogen following microtrauma to the endometrial-myometrial junction and increased uterine peristalsis activity .Adenomyosis's effects on fertility remains unclear, even though uterine peristalsis activity negatively affects sperm and embryo transfer (5). Based on the last meta-analysis published on the effect of adenomyosis on pregnancy outcomes following assisted reproductive technology, it is concluded that adenomyosis hurts in vitro fertilization clinical outcomes; therefore, pretreatment with the use of long-term gonadotropin-releasing hormone agonist (GnRHa) or long protocol could be advantageous (6).Hormonal replacement therapy (HRT) is a common protocol for frozen embryo transfer (FET) cycles because of its more flexible program, enabling physicians to choose the day of embryo transfer suitable for women with or without regular ovulation. This protocol uses estrogen supplementation for endometrial preparation . Pretreatment with a GnRHa added to the HRT protocol, results in better pituitary downregulation (9). The GnRHa protocol reduces tissue inflammation and angiogenesis and increases the apoptotic index, which improves endometrial receptivity in adenomyosis .Local hypoestrogenism is effective in myometrial hyperperistalsis activities and benefits implantation . There is insufficient evidence to support preferring an endometrial preparation protocol with or without GnRHa for FET in these women. Li and colleagues, in a retrospective study, reported that pretreatment with GnRHa in an HRT cycle did not improve the clinical pregnancy or live birth rates of following FET among infertile women with adenomyosis (13).Due to the deficiency of clinical trial studies on endometrial preparation using HRT cycles with and without GnRHa pretreatment in adenomyosis cases, we designed a randomized clinical trial to compare the pregnancy outcomes in infertile women with adenomyosis who underwent HRT cycles with and without long-term pituitary downregulation with GnRHa.A phase III randomized clinical trial study was conducted on 140 adenomyosis cases, who underwent FET cycles at Arash Women's hospital , Tehran, Iran from May 2020 to March 2021.The diagnostic criteria of adenomyosis in vaginal ultrasonography included: the presence of myometrial cysts, echogenic striation, nodules, cystic striation, myometrial thickening, enlarged global uterus, disrupted myometrial-endometrial junction, and posterior diameter of the myometrium that is larger than its anterior diameter , which was accomplished by exclusively an expert gynecology sonographer using a PHILIPS EPIQ-7 3D ultrasonography machine (Netherlands). Adenomyosis was classified as diffuse and focal according to the ultrasonographic characteristics defined earlier (16).The participants aged between 30-45 yr, who had a normal uterine cavity that underwent the 1The history of menorrhagia, dysmenorrhea, or dyspareunia and other concomitant diseases, such as endometriosis and myoma diagnosis, have been examined and recorded.The sample size was estimated to be a minimum of 130 (n = 65/ each) by considering the significance level of 5%, the power of 80%, according to the rate of clinical pregnancy between 2 groups (p1 = 51.35%) (p2 = 24.83%), and used the following formula based on the previous study (11). Participants were allocated randomly into HRT and HRT+GnRHa pretreatment group (HRT+GnRHa) (n = 70/ each). The block randomization method was designed by the epidemiologist using STATA software, version 13. The type of study group was placed in a sealed envelope, and when the physicians approved the participants' eligibility for the study, the midwife then delivered the envelope to them. The researcher who followed up on the pregnancy results and the statistician did not know about the study grouping of the participants.All top-quality embryos were frozen by the vitrification strategy 3 days after ovum pick-up for the research. Briefly, the embryo morphology was defined according to the criteria of previous study by evaluating the number and normality of blastomeres arrangement and the degree of fragmentation on the 3Due to the need for less hormonal monitoring, fewer women visit for ultrasound monitoring, and greater flexibility is observed in determining the day of embryo transfer according to the physician and individual preferences, HRT cycles were used instead of natural processes for FET embryo transfer.In the HRT+GnRHa group, 2 doses of leuprolide acetate  3.75 mg were prescribed through the early follicular stage of the menstrual cycle and 28 days afterward, and the HRT protocol was initiated in the following 10-14 days. In both groups, 2 mg estradiol valerate  was administered daily, increasing the dose to 6 mg daily. A vaginal ultrasound was performed 10-14 days after estrogen supplementation to monitor endometrial thickness. When endometrial thickness exceeded The number of transferred embryos was chosen based on the maternal age and embryo quality. 2 or a maximum of 3 cleavage-stage embryos were for the most part transferred on the 4Embryo transfer was canceled if the optimal endometrial thickness was not achieved after 20 days. Serum β-human chorionic gonadotropin levels were measured 14-16 days after ET. If the test was positive, daily estradiol valerate  and progesterone supplementation  were continued until the 12The endometrial pattern was determined 10-14 days after estradiol administration by transvaginal ultrasound, which was classified into 3 patterns;  (18).The primary outcomes were chemical (positive beta human chorionic gonadotropin test 14 days after ET) and clinical pregnancy (the presence of at least 1 fetus with heart activity at 4-6 wk following ET) rates. Secondary outcomes, including twin pregnancy, miscarriage, and live birth rates, were followed up and reported. A twin pregnancy was detected on observation of 2 gestational sacs and the fetal poles with heartbeat in an ultrasound examination at 6-7 wk following ET. The miscarriage rate is considered as the loss of a clinical pregnancy before 20 wk of gestation. Live birth was defined as the delivery of a fetus that shows evidence of life after being entirely outside of the uterus, regardless of the duration of pregnancy. The pregnancy outcomes were reported per ET cycles, and twin births were considered as one live birth.The intention of the research was clarified to the samples, and all of them completed the informed agreement form, which was ready according to the Declaration of Helsinki. This study was approved by the Ethics Committee of Arash hospital of Tehran University of Medical Sciences, Tehran, Iran (Code: IR.TUMS.MEDICINE.REC.1399.034) and is registered on the IRCT website, which has been updated on January 01, 2023.t test, and if data were skewed Mann-Whitney U test was used. To analyze categorical variables, we used Chi-square or Fisher's exact test as needed. Univariable and multivariable logistic regression analysis were performed to detect significant related factors to clinical pregnancy rate individually and in a group model. All statistical analyses were performed using statistical package for the social sciences , and statistical significance was assumed at p Mean Among 140 participants, 5 and 4 FET cycles were canceled in HRT with and without GnRHa pretreatment groups, respectively, and one woman avoided participating in the study plan. The final analysis included 130 cases with adenomyosis .The demographic and baseline clinical characteristics of the cases were compared between groups. The means of women's age at transfer time had no significant difference between groups (p = 0.63). Also, no significant difference was observed between groups in terms of body mass index, type of infertility, cause of infertility, duration of infertility, and ET failure history. The women in pretreatment with the GnRHa group were more likely to have a previous history of FET cycles. In addition, the means of endometrial thickness at starting progesterone administration day were similar in both groups, and the predominant pattern in both groups was the triple line pattern (p = 0.56). No significant differences were observed between groups in the number of transferred embryos and embryo quality. Total estrogen dose and duration of its consumption were significantly higher in HRT with the GnRHa pretreatment group .The pregnancy outcomes have been compared after fresh ET cycles with and without GnRHa pretreatment and FET cycles following GnRHa pretreatment in a retrospective study. GnRHa pretreatment are associated with higher duration of the stimulation and total dose of gonadotropin, which led to a notably higher number of recovered oocytes in fresh cycles. The clinical pregnancy rate in group C (FET cycles) tended to be higher than those in groups B (fresh with) and A (fresh without), but without a significant difference (19). Recently, the pregnancy outcomes between women who underwent HRT cycles with and without GnRHa pretreatment have been compared in a large retrospective cohort study. They suggested GnRHa pretreatment may improve clinical pregnancy and live birth rate in women with endometriosis (20).Adenomyosis is an estrogen-responsive disease, and pituitary downregulation with GnRHa for 1-3 months might increase the pregnancy rate (5). GnRHa decreases the inflammatory reaction and angiogenesis in adenomyosis tissues. Also, as GnRHa suppress the hypothalamus–pituitary–ovarian axis and induce a hypoestrogenic situation, leading to adenomyosis cell apoptosis and reducing the uterine size . Supraphysiologic estrogen concentrations lead to decreased integrin β3, osteopontin, and leukemia-inhibiting factor as endometrial receptivity markers during the endometrium implantation window in adenomyosis .In the current study, no superiority was observed between HRT+GnRHa and HRT cycles in pregnancy outcomes. On the other hand, we showed that the HRT cycle with GnRHa pretreatment causes significantly prolonged days and doses of estradiol consumption. In agreement with the present finding, in a retrospective study, it was concluded that GnRHa downregulation based on an HRT for the endometrial preparation in the FET cycle among infertile women with adenomyosis did not improve the rates of clinical pregnancy or live birth compared to HRT alone (13).Due to the shorter time reaching embryo transfer in the HRT group and a lower rate of side effects and costs compared with GnRHa, this protocol is more patient-friendly than the HRT+GnRHa protocol, simultaneously the GnRHa could result in the delayed resumption of spontaneous ovulation after the FET cycle failures .The design of a clinical trial with a significant sample size is the strength of the present study. It was ideal to transfer a single euploid blastocyst to control the embryo quality factor; however, we could not apply this factor in our study due to limitations. Since the 2 groups were homogeneous in terms of baseline characteristics and no significant variable affecting clinical pregnancy was found in logistic regression tests, the findings of the present study are reliable.The present study indicated that endometrial preparation for FET with and without suppression by GnRHa provides similar results in pregnancy outcomes. Moreover, the HRT cycle time interval to embryo transfer is shorter, so this protocol is much simpler, better, and more cost-effective than the HRT cycle with GnRHa pretreatment. Furthermore, prospective RCTs are needed to validate the optimal protocol for FET cycles in cases with adenomyosis.The authors declare that there is no conflict of interest.


Since the beginning of SESN protein development, they have attracted highly progressive attention due to their regulatory role in multiple signalling pathways. Through their antioxidant activity and autophagy regulation implication, they can function as powerful antioxidants to reduce oxidative stress in cells. SESN proteins received special attention in the field of regulation of reactive oxygen species level in the cell and its interplay with signalling pathways determining energy and nutrient homeostasis. Since perturbations in these pathways are implicated in cancer onset and development, SESNs might constitute potential novel therapeutic targets of broad interest. In this review, we discuss the impact of SESN proteins on anti-cancer therapy based on naturally occurring compounds and conventionally used drugs that influence oxidative stress and autophagy-induced cellular signalling pathways. The significant changes in reactive oxygen species level and nutrient status in cancer cells generate subsequent biological effect through the regulation of SESN-dependent pathways. Thus, SESN may serve as the key molecule for regulating anti-cancer drugs’ induced cellular response. Sestrin (SESN) protein family is composed of three distinct members: SESN1, SESN2 and SESN3. These highly conserved proteins are encoded by genes whose expression is regulated by various conditions including hypoxia, oxidative stress, metabolic stress, or DNA damage , mTORC1, nuclear factor erythroid 2-related factor 2 (Nrf2), mitogen-activated protein kinases (MAPKs) and transforming growth factor β (TGF-β)   in an active form  in Similar structural resemblance SESN2 protein to AhpD in a sense of catalytic Cys125 was proved by Budanov et al. . As propTo understand the regulatory function of SESN 2 protein towards mTORC1, it is worth taking a closer look at the Sesn-C domain, which was revealed by crystallographic studies of Kim et al. , so far Based on these findings, we could speculate that SESN2 protein has two independently working domains, which could explain such diverse functionalities of SESN2 proteins. The open issue is that the crystal structure of SESN2 protein is also characteristic for the SESN1 and SESN3 proteins. It is observed that the Sesn-C domain sequence is conserved among all SESN proteins that suggest its importance for the mTORC1-regulating function  tissues and HT-29, SW480, SW620 and LoVo cell lines. Moreover, the expression of SESN2 in SW620 and LoVo cells, derived from the metastatic site of CRC, was significantly lower than that in the HT‑29 and SW480 cells, derived from the primary lesion of CRC  tissue and correlated with shorter overall survival and disease-free survival in patients with endometrial cancer  tissues among them 114 samples were characterized by low expression of SESN2 and 96 samples were characterized by high expression of SESN2. Moreover, low SESN2 expression was correlated with the characteristic of aggressive NSCLC including poor tumour differentiation, advanced TNM stage and lymph node metastasis, in contrast to high SESN2 expression. Further, patients with low SESN2 expression had worse overall survival compared with those with high SESN2 expression . Thus, the expression level of SESN2 could be important in the observation of prognosis in NSCLC. Complementary to these results, Ding and co-workers have shown that the expression levels of the Altogether, SESN proteins and SESN2 in particular are implicated in tumour onset and progression of the several types of human cancer. Their expression level could be used as a prognostic marker and clinicopathological characteristics of patients. However, the complex nature of cancer makes it difficult to judge whether SESN proteins are solely anti-cancerous or pro-cancerous and poses challenging questions about the role of SESNs in tumour biology. The potency of SESN proteins to cross talk with a plethora of regulating targets in a specific cellular context pose only a few obstacles to overcome before SESNs become an effective anti-cancer therapy. Nevertheless, we made the attempt to demonstrate the evidence for an eminent role of SESN proteins in anti-cancer therapy in the following section.SESN are stress-inducible proteins that modulate the antioxidant and autophagy signalling pathways that protect cells from various harmful stimuli. Since perturbations in these pathways are implicated in cancer onset and development, SESNs might constitute potential novel therapeutic targets of broad interest. In this section, we discuss the contribution of SESNs regulatory networks to the pharmacological effects of different anti-cancer substances.Naturally occurring compounds from dietary sources are frequently investigated for their anti-cancer activities. Some of them are reported to exert their activities through direct modulation of SESN proteins expression. One of them is cucurbitacin B, a tetracyclic triterpenoid present in plants of the Cucurbitaceae family, i.e. pumpkins, gourds and squashes  cells. The phenomenon, reported by Hua et al. , occurs SESN proteins hold great potential to become a beneficial target for completely novel compounds and also for well-known anti-cancer therapies. The potential antitumour activity of SESN proteins lies in their possibility to control ROS and regulate cell metabolism and autophagy. Complementary to these observations, Kim et al.  reportedAnother study looked at phytochemicals present in rosemary, especially carnosol which has the potential to promote gastrointestinal health by activating the antioxidant SESN2 , SESN1 and Nrf2 -induced Akt–mTOR signalling and acts as a radiation sensitizer in breast cancer cells. Moreover, they have shown that SESN2 mediates IR-induced AMPK expression and facilitates the radiosensitization of breast cancer cells , a chemotherapeutic agent widely used in the treatment of colorectal cancer, and SESN2 expression. The authors clearly demonstrated that colon cancer HCT116 and HT29 cell lines treated with 5-FU expressed a higher level of SESN2 and increased transcripts of SESN1, but not of SESN3 protein. In contrast to the previous study, 5-FU did not induce the ROS production in colon cancer cell lines; thus, a different molecular mechanism was implicated in SESN2 upregulaion. The authors proposed that 5-FU induces the expression of SESN2 in p53-dependent manner  stress-inducing drugs such as nelfinavir, bortezomib and HSP90 inhibitors for the treatment of cancer. The observed interest is due to a pro-apoptotic feature of ER stress and the induction of autophagy  such as suberoylanilide hydroxamic acid (SAHA), trichostatin A (TSA), and depsipeptide. They are a class of compounds that interfere with the function of histone deacetylase and induce cell cycle arrest, differentiation and apoptosis Emanuele . The maiIn our review, we have discussed various aspects of the interplay between anti-cancer substances and SESN proteins’ abnormal expression and how cancer cells respond to these interactions. The presented studies revealed that multiple cancer cells differ with respect to a complex interaction network of SESN proteins implicated in anti-cancer therapy. A detailed insight into the oxidative stress–autophagy–SESNs network is of importance for the application of SESN-modulating anti-cancer drugs in the future. Anti-cancer drugs that manipulate the level of ROS, and in this way influence oxidative stress and autophagy-induced cellular signalling pathways, may be used alone or in combination with other biological response modifiers such as SESN proteins. SESN proteins may be the determinants of sensitivity to anti-cancer treatments as they are activated in response to radiotherapy and many chemotherapeutic drugs and may support cell death in response to certain treatment conditions. The proposed mechanism could be that anti-cancer drugs or radiotherapy administration causes a dysregulation of intracellular signalling pathways and increases oxidative stress. It is important to bear in mind that cancerous cells may try to adapt to a new oxidative stress condition and are capable of dealing with cellular ROS by rapid induction of survival mechanisms promoting carcinogenesis. Given the ability of oxidative stress to activate the SESN proteins, they could be beneficial for tumour cell survival at an early stage of anti-cancer therapy. The mechanisms, such as attenuation of oxidative stress and augmentation of autophagy, which SESN proteins could implicate to promote tumour growth under stress conditions triggered by chemotherapy and radiotherapy, are relatively complex. However, the persistent and severe oxidative stress elicited by proper doses and regime of anti-cancer therapy could overcome the cancerous defence mechanisms at least until new mutations and genetic adaptation occur, which gives a considerable advantage to the new cancer cell population. For this purpose, future preclinical and clinical studies are needed to fully clarify the clinical utility of SESN proteins.Another important issue is to understand which factors determine whether SESN proteins work as anti-cancerous or pro-cancerous agent in complex process of carcinogenesis. Moreover, it remains controversial and needs further explanation why the expression of SESN proteins is inconsistent in different tumours. Comprehensive studies have shown that low expression of SESN proteins is characteristic of aggressive and primary invasive lung cancer, bladder cancer, colon cancer and prostate cancer. The suggested explanation could be that cancer cells have to silence the antioxidant defence system to sustain proper ROS level which further activates the EMT process and allows for cancer progression. Moreover, the low expression of SESNs in cancer cells could be the consequence of the coexistence of a mutated p53 protein, which regulates their expression. Finally, the inhibition of SESN protein activity could be one of the mechanisms that allows to overstimulate mTORC1 signalling pathways and accelerate the cancer cell proliferation in unfavourable conditions such as nutrient deficiency or ATP depletion. Nevertheless, the controversial issue is why aggressive and metastatic endometrial cancer is characterized by an increased expression of SESN proteins. Bearing in mind the complex and insidious nature of carcinogenesis, the answer to this challenging question could bring some dilemma. One of the proposed explanations could be that higher SESN proteins are a compensatory mechanism and/or adaptive response to specific circumstances of endometrial cancer. However, it requires further validation to fully understand the detailed mechanism responsible for such phenomenon.In conclusion, SESN proteins seem to deserve the researchers’ attention due to their potential to uncover interesting facts about carcinogenesis and anti-cancer therapy. Their pro-survival role in cancer cells could be used as one of the strategies to nullify the pathways controlled by SESN proteins to alleviate cancer progression. Additionally, developing new comprehensive strategies for the treatment of a particular type of cancer based on the levels of SESN proteins’ expression at different stages of cancer development and progression would be an interesting challenge.This study is primarily based on the review of the experiments that show SESN proteins as potential modifiers of cancer cells’ response to anti-cancer therapy, but not as direct molecular targets of the applied anti-cancer therapy. We speculate that the observed phenomenon could be attributed to the emerging interest in SESN proteins and a very early stage of research over the SESN proteins’ role in cancer biology. However, diverse functions of SESN proteins, cross talk with a plethora of signalling pathways in a specific cellular context and the complex nature of cancer create only a few obstacles to overcome before SESNs become an effective target of anti-cancer therapy.