Acute disseminated encephalomyelitis and mild encephalopathy with reversible splenial lesion are autoimmune demyelinating disorders of central nervous system. Diagnosis remains clinical, aided by neuroimaging confirmation and excluding other causes. In the absence of a biological marker, the diagnosis of these entities based on clinical and imaging criteria could overlap.  We describe a 22-year-old woman developing mild neurological signs after an upper tract infection, a brain magnetic resonance image revealed confluent, symmetrical white matter lesions with corpus callosum involvement; after extensive ancillary testing that ruled out secondary causes we concluded that this subject had a post infectious encephalitis sharing clinical and imaging criteria for acute disseminated encephalomyelitis. However, mild encephalopathy with reversible splenial lesion could be an alternate diagnosis for this subject. Treatment with methylprednisolone completely solved both the clinical and image abnormalities without relapsing for more than 3 years of follow-up.  Both acute disseminated encephalomyelitis and mild encephalopathy with reversible splenial lesion share clinical and radiological features. A biological marker is needed to differentiate among these entities, since overlap is seen according to current criteria. Acute disseminated encephalomyelitis (ADEM) is a multifocal inflammatory demyelinating disease of the central nervous system (CNS) which occurs most commonly in children after a bacterial, viral process or vaccination. It is thought that an immune response against these infectious agents cross-react with self-myelin peptides, hence leading to an autoimmune response .In most cases the disease has a monophasic course, although it can also present as a relapsing illness. ADEM usually begins from 2 days to 4 weeks after infection or vaccination. The typical course begins with a sudden onset of encephalopathy and several focal neurological deficits such as weakness of extremities, ataxia, cranial nerve palsies, seizures, myelitis and optic neuritis among others. Subjects also develop systemic symptoms such as headache, fever and vomiting [Magnetic resonance imaging (MRI) of the brain and spine is the most useful ancillary test for acute demyelination . The newAn important differential diagnosis of ADEM is mild encephalopathy with reversible splenial lesion (MERS), this entity is a clinico-radiological syndrome characterized by a transient mild encephalopathy and a reversible lesion in the splenium of the corpus callosum on MRI. This syndrome has almost universally been described in children from Japan and East Asia . The aimA 22-year-old woman was admitted into the hospital for a 2-week course of diplopia, frontal headache and retro-ocular pain following an unspecified self-limited upper respiratory tract infection 15 day prior to the appearance of these neurological symptoms. Neurologic exam showed conjugated primary-gaze diplopia and generalized hyperreflexia. Fundoscopy showed optic nerve pallor bilaterally. Brain MRI was performed which showed extensive T2 and FLAIR white matter hyperintense lesions as well as in brainstem and splenium of corpus callosum . LaboratADEM in adults is a rare manifestation of post infectious disease , howeverThe diagnosis of ADEM remains clinical, aided by neuroimaging confirmation and the exclusion of other causes . ClinicaFive patterns of cerebral involvement have been proposed to classify the MRI findings in ADEM among children and adolescents: 1. ADEM with small lesions (less than 5 mm); 2. ADEM with large, confluent, or tumefactive lesions; 3. ADEM with additional symmetrical bithalamic involvement; 4. Acute hemorrhagic encephalomyelitis (AHEM); and 5. ADEM with pseudo-leukodystrophic pattern, with a diffuse, bilateral, symmetrical, and usually non-enhanced white matter involvement [The diffuse, symmetrical, and usually non-enhancing white matter involvement can be rarely found in subjects with ADEM, with all the reported cases seen during infancy and adolescence. Clinically, most of them were associated with seizures, fever and aggressive neurologic involvement. Although these findings in neuroimaging are not the most typical pattern of ADEM, the exclusion of other entities such as a history of previous infection or vaccination points toward a diagnosis of ADEM. Also, the response to methylprednisolone supports the diagnosis in a retrospective manner –13.Since ADEM is a diagnosis of exclusion , other dClinical clues in the present case favoring a diagnosis of ADEM are: prior upper tract infection, unremarkable laboratory studies, confluent symmetrical white matter lesions, the complete response to methylprednisolone and the monophasic course, remaining symptomatically free for more than 3 years of follow up. Nevertheless, atypical MRI findings such as corpus callosum involvement, a confluent, symmetrical white matter lesions and subtle neurological involvement makes also MERS type 2 a feasible diagnosis.MERS is a clinical and radiological syndrome characterized by transient lesions at the splenium and associated frontal white matter . The diaCurrently, availability of biomarkers have been made possible not only with the diagnosis of complex entities but also understanding of their pathophysiological processes. In the case of demyelinating diseases, the presence of antibodies against myelin oligodendrocyte glycoprotein (anti-MOG) have been associated with acute disseminated encephalomyelitis, recurrent and bilateral optic neuritis and transverse myelitis in both children and adults; however, they have not been tested in the differential diagnosis of ADEM and MERS (in case they are different and not just part of a spectrum of the same disease). Additionally, the sensitivity of this antibody for a diagnosis of ADEM is as low as of 40% . We did A recent article that summarizes the evidence of rotavirus associated MERS found a total of 13 reported cases of MERS and showed that 10 were from Japan, one from Korea, one from China and one from Poland; the median age at presentation was 2 years (range 1–6 years) and in all cases, MERS was preceded by symptoms of gastroenteritis, such as vomiting, diarrhea and fever; Seizures  and disturbance of consciousness  were the most common neurological signs. Twelve patients (92%) had an isolated lesion in the splenium of the corpus callosum, and one patient (8%) had lesions in the splenium and genu of the corpus callosum . AnotherAs our subject of study did not have all the clinical features  or the demographic characteristics of the reported cases of MERS (Asian ethnicity), it does not seem to fulfill all the criteria for that entity, besides that, our case has also imaging features not previously described for MERS such as infratentorial hyperintense images and confluent, symmetrical white matter lesions in MRI; it is important to note that the involvement of corpus callosum and restricted diffusion has also been described in the acute phase of ADEM  and the Taking together the demographic, clinical and imaging features seen in our subject makes the diagnosis of ADEM and MERS overlap, a well-known condition in the scenario of post infectious encephalitis , in factIn this respect, and possibly related with the same spectrum of disease, tumefactive lesions (demyelinating lesions of greater than 2 cm) involving the corpus callosum can also occur in ADEM but are most closely related with MS where they often occur at the time of first presentation, either isolated or in association with other typical MS demyelinating lesions. In the largest published series of tumefactive demyelinating lesions among 168 patients, 10 patients (7%) exhibited a so-called “butterfly” appearance with symmetrical involvement of the corpus callosum and both cerebral hemispheres , 22.“Transient splenial lesions” of the corpus callosum have been used to describe more restricted lesions among MERS cases, however, this term has also been employed to describe not only CNS inflammatory diseases such as Kawasaki disease, systemic lupus erythematosus and CNS infections, but also, non-inflammatory entities such as seizures (including status epilepticus), anticonvulsant use, hypoglycemia and other metabolic disturbances , 23.Regarding pharmacological management, most of the published evidence for ADEM suggests high-dose corticosteroids as the first-line of treatment. Either methylprednisolone (20–30 mg/kg/day to a maximum dose of 1 g/day), or dexamethasone (1 mg/kg/day), followed by oral prednisone tapering for 4–6 weeks are the suggested schemas . In the The prognosis in ADEM is more severe in adults with respect to hospitalization, intensive-care unit admission, recovery and mortality . The benThe present case showing confluent, symmetrical white matter lesions and corpus callosum involvement after an infectious disease shares clinical and radiological features of acute disseminated encephalomyelitis and mild encephalopathy with reversible splenial lesion. If MERS and ADEM are not part of the same spectrum, it is necessary to develop a biological marker that clearly distinguishes between these two entities, however due to the overlap they may be part of the same spectrum of disease.


Vascular stiffening in the pulmonary arterial bed is increasingly recognized as an early disease marker and contributor to right ventricular workload in pulmonary hypertension. Changes in pulmonary artery stiffness throughout the pulmonary vascular tree lead to physiologic alterations in pressure and flow characteristics that may contribute to disease progression. These findings have led to a greater focus on the potential contributions of extracellular matrix remodeling and mechanical signaling to pulmonary hypertension pathogenesis. Several recent studies have demonstrated that the cellular response to vascular stiffness includes upregulation of signaling pathways that precipitate further vascular remodeling, a process known as mechanobiological feedback. The extracellular matrix modifiers, mechanosensors, and mechanotransducers responsible for this process have become increasingly well-recognized. In this review, we discuss the impact of vascular stiffening on pulmonary hypertension morbidity and mortality, evidence in favor of mechanobiological feedback in pulmonary hypertension pathogenesis, and the major contributors to mechanical signaling in the pulmonary vasculature. Pulmonary Hypertension is characterized by progressive pulmonary vascular remodeling that leads to exertional dyspnea, severe hypoxemia, and ultimately to right heart failure. The most severe form of the disease, PAH, initially and primarily affects the pulmonary arterial tree, and is associated with a 5-year survival of 61% . Other fin vivo, including vascular smooth muscle tone, arrangement and structure of arterial laminae, local composition of extracellular matrix, and alterations in arterial geometry .Pulmonary arterial stiffness is increasingly appreciated as an important marker and predictor of disease severity and poor functional status in PH . MultiplThis review will briefly address our current understanding of the clinical impact of pulmonary vascular stiffness. We will then focus on evidence for PA stiffening as a critical early driver of vascular remodeling – a process known as mechanobiological feedback. A close examination of the molecular mechanisms by which vascular cells promote, sense, and pathologically respond to stiffening is critical for our understanding of this process. Therapeutic targeting of key mechanotransduction mediators offers the potential to disrupt mechanobiological feedback and prevent or reverse pathologic vascular remodeling.Increased vascular stiffness in the systemic circulation is strongly associated with incident systemic hypertension, and has been convincingly shown to precede the development of hypertension in multiple cohorts . FurtherSeveral groups have examined associations between mortality and non-invasive measures of proximal pulmonary vascular stiffness. Measurement techniques have varied across groups, and include intravascular ultrasound  or MRI  to measuBeyond its utility as a marker of mortality, PA stiffness may better predict early disease and functional status in PH than PVR and other traditional clinical parameters . One groFigure 1). Physiologically, there is strong evidence that arterial stiffening contributes significantly to RV afterload and RV failure. Standard measurements of RV afterload using PVR account for only the steady-flow component of RV work, however, arterial stiffness is the critical determinate of RV pulsatile afterload  have an inverse hyperbolic relationship . In partIncreasing evidence from disease models also implicates a critical role for PA stiffening in a positive feedback cycle of pathologic vascular remodeling. Distal vasculopathy can promote increased mean pressures, resulting in large vessel wall thickening, vessel dilation, and extensive alterations in ECM content . Stiffenex vivo biaxial strain testing and accompanying two-photon microscopy in explanted human tissues demonstrated severe elastin fragmentation and collagen accumulation in PH that correlated well with collagen-predominant (stiff) mechanics even under low-strain conditions . They found a significant (∼25%) increase in effective elastic modulus and decreased compliance of proximal mouse PAs that correlated histologically with proportional thickening of both collagen and elastin elements of the arterial wall  rat model of PH within the first few days after injection, and weeks before the development of hemodynamic changes . Serine in vivo lead to compensatory vascular remodeling that functions to maintain shear stresses near physiologic levels, but may also contribute to pathological processes such as atherosclerosis  on human PAECs. Compared to normal flow pulsatility, high flow pulsatility led to attenuated release of the pulmonary vasodilators NO and prostaglandin-F1α (PGF1α) and enhanced release of the potent vasoconstrictor endothelin  by Meyrick and Reid in their initial studies of hypoxia- and Crotolaria-induced PH in rats ,b. This Our recent work has added to the field by directly characterizing the stiffness of the pulmonary vasculature locally at the micron scale in models of PH and human PAH. To do so, we developed a methodology to characterize the local elastic properties of the lung using atomic force microscopy (AFM) . OptimalUsing this AFM approach, we examined the spatial and temporal distribution of PA stiffening in both the MCT and sugen-hypoxia rat models of PH . We founFigure 1; These changes in the local mechanical environment in early PH suggest a potential role for PA stiffness in the progression of disease. From a physiologic standpoint, smaller vessels contribute significantly to total arterial compliance as well as to vascular resistance; thus, increased stiffness and muscularization will impact both static and oscillatory RV workload . Due to in vitro using discrete stiffness polyacrylamide hydrogels .Human PASMCs and PAECs grown on hydrogels that span the range from normal parenchyma to highly remodeled vessels (shear modulus 0.1–25.6 kPa) show a robust proliferative response to matrix stiffness . In PASMfeedback . Over thFigure 2).Vascular stiffness ultimately arises from a combination of factors, including increased ECM deposition, matrix stiffening, vascular cell proliferation/hypertrophy, and active smooth muscle contraction. The major structural ECM components and their role in large vessel stiffness were discussed previously, however, matrix composition and mechanical properties are also altered by enzymatic activity that is closely regulated at the cellular level  that likely play a role in altering the vascular mechanical microenvironment. MMP2 and MMP9 are metalloproteinases with diverse ECM cleavage functions which were initially identified by their ability to degrade collagen IV of the basement membrane; they are also referred to as gelatinases based on their efficient cleavage of denatured collagen I. Elevated MMP2 expression and collagen IV degradation are seen in PH neointimal lesions , and gelex vivo . Much reMMPs also have extensive non-matrix secondary effects via cytokine processing and release from the ECM that likely contribute to the complexity of their regulation and their role in disease . On a moin vivo. We verified the impact of LOX inhibition on hypoxia-induced PH, and tied it directly to inhibition of this mechanotransduction circuit. More importantly, we closely examined the impact of LOX inhibition in the MCT PH model, and demonstrated decreased collagen deposition and remodeling, reduced medial thickening, and directly decreased arterial stiffness as assessed by AFM  is a calcium-dependent crosslinking enzyme that is known to remodel collagen I and other components of the ECM, resulting in increased matrix stability and tissue rigidity . In the All adherent cells derive critical signals from their interactions with the ECM and their mechanical microenvironment in order to regulate cell shape, survival, proliferation, and other phenotypes. Mechanical disruption can be converted to chemical signaling directly via mechanosensitive ion channels. In endothelial cells, a number of mechanosensitive channels, including the TRPV4 and PIEZO1 calcium channels and the inwardly rectifying potassium (Kir) channels, are responsible for shear-flow induced vasodilation through activation of eNOS . AlthougThe transmission of mechanical information from the ECM to the cell cytoskeleton and signal transduction machinery is mediated primarily through integrin-based adhesions . Integri1, αv, and α8 signaling are increased in both MCT and chronic hypoxia, whereas α5 and β1 are decreased in chronic hypoxia and α5 and β3 are decreased in the MCT model . For instance, the Src family of tyrosine kinases and FAK are both recruited to focal adhesions, modulate integrin-cytoskeletal links, and regulate each other’s activity . β-catenin is a well-known transcriptional coactivator that is normally targeted for degradation in the cytosol via phosphorylation by glycogen synthase kinase-3β (GSK3β), the core member of the β-catenin destruction complex. β-catenin activation canonically occurs via wingless/integrase (Wnt) signaling pathways, and leads to β-catenin-dependent activation of processes involved in proliferation, survival, and migration in many cell types. In epithelial cells, mechanical stretch and tissue stiffness lead to activation of β-catenin downstream of RhoA and ROCK activation  is a transcription factor most well-known for its involvement in inflammatory and immune responses, including flow-mediated inflammatory responses in endothelial cells . The SteOne critical link between stiffness-mediated cytoskeletal remodeling and gene expression are the MRTFs. The MRTFs form stable complexes with monomeric soluble actin (G-actin), leading to the sequestration of these complexes in the cytoplasm. Polymerization of G-actin into F-actin filaments and stress fibers in the setting of increased mechanical stress or migration liberates these factors to translocate to the nucleus, where they act as cofactors for serum response factor . ActivitYAP and TAZ are closely related transcriptional modifiers that have recently emerged as powerful effectors of mechanical signaling . YAP/TAZRecent investigations into the complex signaling that regulates YAP/TAZ activity have only now begun to make this process clear. As members of the Hippo pathway, YAP and TAZ are biochemically regulated by phosphorylation by the serine-threonine kinases LATS1 and LATS2, with phosphorylation leading to cytoplasmic sequestration or degradation . HoweverYAP activation is also dependent on sufficient force-loading of integrins to allow talin unfolding and reinforcement of cell-matrix adhesions after integrin-ligand binding . Based uUpon nuclear translocation, YAP and TAZ associate with a number of promoter-specific transcription factors to drive mechanical signaling. The most notable and canonical of these factors are members of the transcriptional enhancer activator domain (TEAD) family, whose downstream products drive cellular proliferation and survival . HoweverRecent studies have revealed important roles for YAP and TAZ in vascular pathology and PH development. In vascular smooth muscle, YAP is induced after injury and promotes cellular migration, proliferation, and neointimal formation . In PH, Recent studies of the nuclear lamina have identified several key mechanosensing proteins that connect the nucleus to the actin cytoskeleton (now identified as the LINC complex) . Beyond Like most significant cellular inputs, mechanical forces are likely to induce epigenetic changes in chromatin remodeling via DNA methylation and histone modifications; however, this process is relatively understudied. Some recent examinations have found that matrix stiffness and mechanical inputs can alter chromatin organization  and incrin vivo, demonstrating disruption of mechanobiological feedback  biology has led to the examination of miR regulation by mechanical signaling. A recent elegant investigation by feedback . This trfeedback .Naturally, given the numerous miRs and their vast networks of targets, there are many miRs that have been found to modulate mechanical signaling pathways, including ECM components , FAK Es, β-catenOver the past several years, the increasing evidence for early development of PA stiffening and its contribution to RV workload in PH has led to an increased focus on arterial stiffness changes in the pathogenesis and potential early treatment of disease. Arterial stiffening has been found to occur fairly early throughout the pulmonary vasculature, affecting both large elastic arteries and small distal vessels. The downstream effects of this vascular stiffening include alterations in flow characteristics and changes in ECM composition that predispose to inflammation and continued pathologic vascular remodeling. The molecular mechanosensors that facilitate this process are now beginning to be understood, and their links to downstream signaling that locally reinforce matrix stiffening and force transmission delineated. Multiple recent studies have highlighted this process during PH development, and in so doing have demonstrated a potential therapeutic effect of disrupting this feedback loop. Further study of mechanobiological feedback in PH will be needed to more thoroughly interrogate these pathways and ultimately identify optimal targets for future therapy.Review conception and design was by PD, LF, and DT. The figures were illustrated by MM. The manuscript was drafted by PD and LF and was approved by all authors.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.


Ongoing concerns about the quality of care provided to nursing home (NH) residents have led the federal government to develop quality measures (QMs) for NHs. Many of these QMs are included in the NH 5-star ratings and reported online via Nursing Home Compare. However, we know little about how NH providers view the QMs, challenges they experience in addressing the measures, and strategies they use to achieve better scores. As part of a broader mixed-methods study to understand how NHs are responding to the 5-star ratings, we conducted interviews with NH personnel (n=110) and observed organizational processes in 12 NHs in three states. We also interviewed policy and industry leaders (n=34) to gain their perspectives. Interviews focused on perceptions of the 5-star ratings, organizational strategies to improve 5-star scores, experiences with the survey/regulatory process, and perceptions and responses to individual QMs. Key themes show that a) NH providers view the QMs as important indicators of quality, but there is variability across indicators; b) providers face challenges related to measurement and definitions for certain QMs ; and c) there are potentially conflicting goals, where some QMs aim to promote safety at the expense of resident autonomy and quality of life and vice versa. This work provides organizational context to the 5-star measures and the balancing act providers engage in to assess and improve their scores. The findings also identify several potentially unintended consequences related to the QMs, which can adversely affect residents, particularly those with more complex care needs.


There is increasing epidemiologic and animal evidence that a low calcium diet increases blood pressure. The aim of this review is to compile the information on the link between low calcium intake and blood pressure. Calcium intake may regulate blood pressure by modifying intracellular calcium in vascular smooth muscle cells and by varying vascular volume through the renin–angiotensin–aldosterone system. Low calcium intake produces a rise of parathyroid gland activity. The parathyroid hormone increases intracellular calcium in vascular smooth muscles resulting in vasoconstriction. Parathyroidectomized animals did not show an increase in blood pressure when fed a low calcium diet as did sham-operated animals. Low calcium intake also increases the synthesis of calcitriol in a direct manner or mediated by parathyroid hormone (PTH). Calcitriol increases intracellular calcium in vascular smooth muscle cells. Both low calcium intake and PTH may stimulate renin release and consequently angiotensin II and aldosterone synthesis. We are willing with this review to promote discussions and contributions to achieve a better understanding of these mechanisms, and if required, the design of future studies. The relationship between calcium intake and blood pressure has been widely studied since the 1980s ,3. DietaThe effect of calcium supplementation on SBP was higher in people aged less than 35 years −2.11 mmHg) and with doses of calcium equal to or over 1500 mg/day (−2.79 mmHg). The higher impact on BP reduction observed in these cases seem to be diluted in the overall revision due to these studies only representing approximately 20% of the participants i) through the PTH receptor (PTHr-1) in vascular smooth muscle, (b) increase calcitriol concentration, and (c) a cross-talk with the renin–angiotensin–aldosterone system (RAAS). The last two will be described in its corresponding sections.Several mechanisms have been proposed to explain the effect of PTH on blood pressure: (a) an increase in cytosolic free calcium concentration , trypsin-inactivated and boiled-resistant peptide . Years lAlthough the existence of PHF may explain the blood pressure changes induced by alterations in a calcium diet, there is still much to know about this mediator. First, the published results have been poorly replicated outside the group that described PHF . On the 2+]i in vascular smooth muscle cells and consequently a rise in blood pressure  or diastolic blood pressure (DBP)  nor in subgroup analysis via basal vitamin D or blood pressure levels i by increasing calcium uptake in many types of cells, including rat vascular smooth muscle cells and aorta-derived cell lines [2+]i  plays a key role in the physiologic regulation of blood pressure. As shown below, several interactions between calcium intake, calcium homeostatic hormones and the RAAS have been described. Renin enzymatic activity consists in the hydrolysis of angiotensinogen to angiotensin I. The acute incubation or infusion of high concentrations of calcium has an inhibitory effect on renin secretion, both in isolated cells and animals ,95,96,97Angiotensin II is the primary active product of the RAAS and a potent vasoconstrictor whose actions are mediated by the type I angiotensin II receptor (AT-1R). Low calcium diets have been shown to increase angiotensin II ,102. In It has also been described that the infusion of angiotensin II produced a significant dose-dependent increase in PTH serum levels . MoreoveAldosterone, a steroid hormone, is synthesized by the zona glomerulosa of the adrenal cortex (CZG) in the adrenal gland. Its primary effect is the regulation of blood pressure through the reabsorption of sodium and excretion of potassium in the distal tubules and the collecting ducts of the nephron , increas2+]i. Angiotensin II, via AT-1R activating the PLC/IP3 cascades, and high extracellular potassium levels via depolarizing the plasma membrane of the cell activating calcium voltage-dependent channels, increase [Ca2+]i and thus aldosterone synthesis i [It has been shown that PTHr-1 stimulates basal steroid secretion  from adrenal cells through both AC/PKA- and PLC/PKC-dependent signaling mechanisms . Adrenal2+]i . In summary, it has been shown that both low calcium intake and PTH stimulate renin release, and consequently, angiotensin II and aldosterone synthesis. In this manuscript, we reviewed the literature exploring the mechanisms involved in the relationship between calcium intake and blood pressure. It has been shown that, particularly in individuals with low calcium intake, an increase in calcium intake reduces blood pressure. We consider that in view of hypertension being a major factor involved in the global burden of disease, the study of interventions that could prevent the development of hypertension should be prioritized . The lin


Oryza sativa L.), including crown roots, lateral roots, root hairs, and root length. Genes involved in the adaptation of roots to the environmental nutrient status are reviewed, and strategies for further study and agricultural applications are discussed. The growth and development of rice roots are controlled by both genetic factors and environmental cues. Plant hormones, especially auxin and cytokinin, play important roles in root growth and development. Understanding the molecular mechanisms regulating root architecture and response to environmental signals can contribute to the genetic improvement of crop root systems, enhancing their adaptation to stressful environmental conditions.Roots are fundamentally important for growth and development, anchoring the plant to its growth substrate, facilitating water and nutrient uptake from the soil, and sensing and responding to environmental signals such as biotic and abiotic stresses. Understanding the molecular mechanisms controlling root architecture is essential for improving nutrient uptake efficiency and crop yields. In this review, we describe the progress being made in the identification of genes and regulatory pathways involved in the development of root systems in rice (The online version of this article (10.1186/s12284-018-0262-x) contains supplementary material, which is available to authorized users. A major challenge for plants is the complexity of the environment in which they must survive. Root systems are vital for addressing this complexity. Roots not only provide structural support to the aerial organs of the plant, and enable the acquisition of water and nutrients that are required for plant growth, but also can monitor environmental conditions in the soil, such as the water content, nutrient levels, and the presence of toxic elements. To ensure an optimal response to changing environmental situations, root systems are continuously reshaped by the initiation and elongation of new roots throughout the growth period, facilitating the plant’s adaptation to biotic and abiotic stresses , and pea (Pisum sativa), while fibrous root systems occur in monocots such as rice (Oryza sativa), wheat (Triticum aestivum), and maize (Zea mays)  analyses. Here, we review the current progress in identifying genes regulating the development of the rice root system, including the primary root, crown root, lateral root, and root hairs. This research will improve our understanding of root system architecture (RSA) development and ultimately enable breeders to select for ideal root architectures promoting higher-yielding crops.qRT9, was found to encode a basic helix-loop-helix (bHLH) transcription factor, OsbHLH120. OsbHLH120 expression was strongly induced by polyethylene glycol, salt, and the drought-response hormone abscisic acid (ABA), suggesting an association with drought avoidance , which encodes a cell wall-localized protein expressed predominantly in the root and shoot, resulted in a shorter primary root, fewer LRs, and short root hairs, supporting the hypothesis that expansins are involved in root growth by mediating cell wall loosening  in early seedlings  when grown in hydroponic culture  had shorter primary roots  and AUXIN SIGNALING F-Box 2 (AFB2), which interact with OsIAA1, an AUXIN/INDOLE ACETIC ACID (AUX/IAA) regulatory protein , an essential manipulator of DNA topology during RNA transcription and DNA replication, strongly reduced rice root elongation and gravitropism by mis-regulating auxin signalling and its associated transporters  formed a shorter root than the WT, while silencing OsERF2 leads to a long-root phenotype. Further experiments revealed that OsERF2 is required for the root response to both ABA and ethylene signalling  accumulation , encoding a LOB-domain transcription factor  and Osgnom1, were found to be allelic lines with mutations in a membrane-associated guanine-nucleotide exchange factor of the ADP-ribosylation factor G protein (GNOM). GNOM1 regulates the traffic of PIN-FORMED 1 (PIN1) auxin efflux carrier proteins, and consequently mediates polar auxin transport, suggesting that appropriate polarized auxin transport mediated by CRL4/OsGNOM1 is required for crown root initiation , suggesting a role for OsPIN1 in the regulation of adventitious root development via auxin pathway , resulted in undeveloped adventitious roots and LRs, and a reduced RAM caused by lower expression of most OsPIN genes, suggesting that OsRPK1 also functions in an auxin-related pathway  in the root tip , was also found to mediate rice crown root development, as the loss-of-function mutant nal1 produced fewer adventitious roots. NAL1 encodes a putative trypsin-like serine/cysteine protease that affects the expression levels of many genes associated with leaf development and auxin transport; consequently, exogenous auxin treatment rescued the nal1 phenotype , is also required for the emergence of crown roots  during crown root initiation; the OsERF3-OsWOX11 interaction likely represses OsRR2 expression during crown root elongation , have provided further evidence that CK signalling plays an important role in crown root emergence and development  family gene, also plays a positive role in crown root formation; overexpressing OsCKX4 was found to increase the number of crown roots but reduce the overall height of the plant. OsCKX4 is a direct target of both the auxin response factor OsARF25 and the CK response regulators OsRR2 and OsRR3  are also essential for crown root development in rice. The WUSCHEL-related homeobox gene brd1 mutant possesses a dysfunctional BR biosynthesis gene, OsBR6ox, and produces fewer crown roots  mutants with impaired SL biosynthesis and signalling produce fewer adventitious roots than the WT  and SL have been implicated in crown root initiation and development. The Though many genes involved in rice crown root development have been identified Fig. , our knoArabidopsis, which revealed a major role for auxin signalling in this process  and lrt2, were identified by their lack of LRs, and were found to be less sensitive to auxin  mutant also formed significantly shorter LRs and was less sensitive to exogenous auxin than the WT  and arm2, failed to produce LRs  and NAL3, a pair of duplicated genes encoding WUSCHEL-RELATED HOMEOBOX 3A (OsWOX3A), also mediate LR development via the auxin signalling pathway. The nal2 nal3 double mutant showed a severe reduction in LR number and an increase in root hair number and length, and the expression of the OsPIN genes was also significantly affected  was cloned and functionally identified, and the loss-of-function mutant Oscyp2 was found to exhibit defects in LR formation  is regulated by jasmonic acid (JA) to control the formation of LRs through the production of carbon monoxide , the Arabidopsis ortholog of which encodes a putative calcium-binding protein, produce much shorter LRs when grown in media containing ABA, suggesting that OsDSR-1 may act as a positive regulator during the ABA-mediated inhibition of LR development , encoding a stearoyl-acyl carrier protein from the fatty acid desaturase family, affects overall fatty acid desaturation and also functions as a positive regulator of LR growth , exhibited defective crown root and embryonic seminal root initiation, but the development of the primary and lateral roots were not affected  contain an auxin responsive element (ARE), suggesting that they are responsive to auxin just like ARL1/CRL1  mutant; however, this gene, which is expressed only in root hair cells, is required for their elongation  and Osrhl1–2 produced very short root hairs without affecting root length or the number of LRs and adventitious roots, suggesting that OsRHL1 functions specifically in root hair elongation  was also found to regulate rice root hair elongation; the loss-of-function mutant osfh1 exhibited root hair defects when grown submerged in solution, but produced normal root hairs in contact with the air. This root hair phenotype could not be rescued by an external supply of hormones or carbohydrates , encoding a phosphatidylinositol transfer protein (PITP), promotes root hair elongation via phospholipid signalling and metabolism, suggesting that the mediation of these processes by PITP is required for root hair elongation in rice  produced longer root hairs, while plants overexpressing OsABI-LIKE 2 (OsABIL2) had attenuated ABA signalling and shorter root hairs  is believed to regulate RSA by regulating the growth angle of the crown roots to adapt to drought conditions; higher levels of DRO1 expression result in deeper rooting that may maintain higher yields under drought conditions , encoding OsPIN2, was also recently identified to regulate root growth angle in rice; the lra1 mutant displays a shallow root system, which may benefit nutrient uptake


Signaling of the receptor tyrosine kinase Axl and its ligand Gas6 is crucially involved in the development of liver fibrosis and hepatocellular carcinoma (HCC) by activation of hepatic stellate cells and modulation of hepatocyte differentiation. Shedding of Axl’s ectodomain leads to the release of soluble Axl (sAxl), which is increased in advanced fibrosis and in early-to-late stage HCC in the presence and absence of cirrhosis. Here, we focus on the dynamics of Axl receptor shedding and delineate possible scenarios how Axl signaling might act as driver of fibrosis progression and HCC development. Based on experimental and clinical data, we discuss the consequences of modifying Axl signaling by sAxl cleavage, as well as cellular strategies to escape from antagonizing effects of Axl shedding by the involvement of the hepatic microenvironment. We emphasize a correlation between free Gas6 and free sAxl levels favoring abundant Gas6/Axl signaling in advanced fibrosis and HCC. The raised scenario provides a solid basis for theranostics allowing the use of sAxl as an accurate diagnostic biomarker of liver cirrhosis and HCC, as well as Axl receptor signaling for therapeutic intervention in stratified HCC patients. Hepatocellular carcinoma (HCC) represents the predominant type of primary liver malignancy showing the sixth most frequent incidence globally and the third most abundant cause of cancer mortality ,2. AboutCTNNB1 (β-catenin), telomerase reverse transcriptase, and TP53, among others, leading to aberrant Wnt signaling, chromosomal instability and escape from cell death . In. In28]. Proteolytic cleavage of extracellular domains of transmembrane proteins is mainly performed by sheddases. This process referred to as ectodomain shedding is a posttranslational mechanism critically required for generating and regulating the active form of multiple growth factors, membrane-bound precursor ligands, adhesion molecules, cell surface receptors and ligand-independent signaling. All these functions of shedding facilitate signaling on host and neighboring cells ,107. ItsShedding of pro-TGF-α by ADAM17 drives tumorigenesis by the release of soluble TGF-α and activation of the epidermal growth factor receptor (EGFR) signaling ,117. ADAIn line, the RTK Axl undergoes a γ-secretase-dependent cleavage after ectodomain shedding generating a soluble ICD . A compaOf note, the extracellular domain of ErbB2 is shedded by ADAMs and MMPs upon receptor activation. Notably, the resulting serum-detectable soluble fragment is able to reflect the activity state of the receptor since the ICD of ErbB2 is shown to be constitutively active ,128. An A previous study by Ekman et al. showed that Gas6 is bound to sAxl in human serum and plasma by an excess of sAxl . The autSNAI1, MMP9 and TGF-β1 in HCC, which are crucially involved in cell invasion and trans-endothelial migration of EMT-transformed hepatocytes [In this scenario, it is also conceivable that Axl transduces an anti-oncogenic signal, which is dampened by sAxl leading to an oncogenic phenotype A. Yet, Gatocytes ,28. Moreatocytes . Consequatocytes ,135. Sinatocytes , the hypRecent findings support the idea of Gas6-dependent Axl signaling in liver fibrosis which has been revealed by Gas6 KO and Axl KO studies, showing reduced fibrogenesis ,102. In If the Gas6 levels exceed the sAxl values, it will indicate that Gas6 overcomes the inhibitory feedback mechanism. This scenario suggests that there might be a switch predisposing fibrosis, cirrhosis or HCC development, where the inhibitory Axl shedding mechanism is circumvented. In the case that serum Gas6 is lower than sAxl, the Gas6/Axl signaling would be dampened, which would rather lead to the abrogation of an anti-fibrotic or anti-oncogenic signal driving fibrosis or HCC. We propose that cleavage of Axl does not contribute to the development or progression of liver fibrosis/cirrhosis and HCC due to the presence of abundant non-shedded Axl receptors overcoming the loss of proteolytically cleaved Axl. Available free Gas6 is then able to bind increasingly expressed Axl receptor and stimulate Gas6/Axl signaling driving HCC progression (The Gas6-independent signaling hypothesis implicates that proteases are recruited to cleave the Axl ectodomain after Gas6-mediated Axl activation (Patients with early diagnosed HCC achieve a five-year survival rate of 60% after liver resection and a five-year survival rate of 67% post transplantation . UnfortuWith respect to the therapeutic intervention, the Gas6/Axl signaling pathway represents a promising target in HCC. For instance, an engineered Axl decoy receptor that was shown to trap Gas6 with higher affinity than the wildtype Axl receptor could lead to effective sequestration of Gas6 and thus, to a decrease of Axl signaling . TargetiEctodomain shedding is a posttranslational mechanism that either acts through the released extracellular domain, the soluble ICD, or bidirectionally through both. Proteolytic cleavage of Axl has not been sufficiently studied yet, which raises multiple questions. In particular, the role of Gas6/Axl signaling in liver fibrosis and HCC requires further elucidation in order to test several hypotheses. As suggested by Ekman et al., ectodomain shedding of Axl could serve as an inhibitory feedback mechanism to shut down the Gas6/Axl signaling route . In thisIn conclusion, the emerging role of Axl in theranostics of HCC is reflected by the promising results of sAxl as an innovative diagnostic biomarker. Beyond, sAxl levels are able to stratify patients according to liver disease stages indicating that Axl as well as sAxl are valuable tools for precision medicine. In addition, CXCL5 might be a promising therapeutic target in Axl/TGF-β-positive patients. To further elucidate the role and mechanism of Gas6/Axl signaling, the Gas6 as well as the Gas6/sAxl complex levels have to be analyzed in blood samples of fibrosis and HCC patients. Examining the combination of Gas6 and Axl will clarify the role and mechanism of ectodomain shedding and might strengthen diagnostic and therapeutic strategies to combat liver fibrosis and HCC.


Understanding the mechanisms underlying the pathogenesis of Sjögren's syndrome (SS) is crucially important in order to be able to discriminate the steps that lead to B cell transformation and promptly identify the patients at risk of lymphomagenesis. The aim of this narrative review is to describe the evidence concerning the role that infections or dysbiosis plays in the epigenetic control of gene expression in SS patients and their possible involvement in B cell lymphomagenesis.  We searched the PubMed and Google Scholar databases and selected a total of 92 articles published during the last 25 years that describe experimental and clinical studies of the potential associations of microbiota and epigenetic aberrations with the risk of B cell lymphoma in SS patients.  The genetic background of SS patients is characterized by the hyperexpression of genes that are mainly involved in regulating the innate and adaptive immune responses and oncogenesis. In addition, salivary gland epithelial cells and lymphocytes both have an altered epigenetic background that enhances the activation of proinflammatory and survival pathways. Dysbiosis or chronic latent infections may tune the immune response and modify the cell epigenetic machinery in such a way as to give B lymphocytes an activated or transformed phenotype. It is also worth noting that transposable integrated retroelements may participate in the pathogenesis of SS and B cell lymphomagenesis by inducing DNA breaks, modulating cell gene expression, or generating aberrant transcripts that chronically stimulate the immune system.  Microorganisms may epigenetically modify target cells and induce their transcriptome to generate an activated or transformed phenotype. The occurrence of lymphoma in more than 15% of SS patients may be the end result of a combination of genetics, epigenetics, and dysbiosis or latent infections. Sjögren's syndrome (SS) is a connective tissue disease that is characterized by chronic inflammation of the exocrine glands  and, in some cases, systemic involvement . It can The initial trigger of SS is still unknown, but subjects with a permissive genetic background are more likely to develop the disease following a microbial infection. Polymorphic variants of the genes involved in the immune response have been associated with susceptibility to SS, and microorganisms such as hepatitis C virus (HCV), Epstein-Barr virus (EBV), and T lymphotropic virus type I have been considered putative inducers of the disease as well as being implicated in carcinogenesis. The mechanisms by means of which viruses can induce precancerous modifications in infected cells are still debated but may include epigenetic alterations or aberrant gene transcription following a viral genome insertion in host cell DNA. SS patients are characterized by an altered epigenetic background that may vary widely depending on the anatomical site and clinical manifestations. Epigenetic alterations  added to genetic predisposition may be explained on the basis of a complex crosstalk between host cells and the microbiome. It has been recently hypothesised that dysbiosis  is a crucial step in the pathogenesis of many autoimmune diseases as it can guide the differentiation and the activation of cells belonging to the innate and adaptive immune system. Studies of patients and experimental models of SS have described oral and gut dysbiosis in terms of its bacterial composition , but theThe aim of this narrative review is to describe the current evidence concerning the role that infections or dysbiosis plays in the epigenetic control of gene expression in SS patients and their possible implication in B cell lymphomagenesis.We searched the PubMed and Google Scholar databases for experimental and clinical studies on the potential associations of microbiota and epigenetic aberrations with the risk of B cell lymphoma in SS patients using a combination of words  to select the most pertinent articles. Priority was given to systematic reviews or meta-analyses and recently published original reports. Articles written in languages other than English were excluded.Ninety-two papers published during the last 25 years were selected. The results were divided into those concerning the pathogenesis of SS, with particular focus on the epigenetic machinery that may be the means by which pathogens control the final phenotype of host cells and those concerning the role of microbial agents in determining SS and SS-associated lymphoma.SS is a chronic autoimmune “epithelitis” whose pathogenesis seems to be triggered by an environmental agent acting on a permissive genetic background . In geneAdaptive immunity is the most involved part of the immune response, and B lymphocytes are the hallmark of the disease. The production of autoantibodies against the ribonucleoprotein complexes Ro/SSA and La/SSB may appear several years before symptom onset, and the presence of classical infiltrates of B and T lymphocytes and plasma cells in minor salivary gland biopsies  is mandatory for making a diagnosis and scoring disease severity . UnderstGenome-wide association studies (GWAS) of SS patients have identified an interferon-I (IFN-I) and IFN-II signature that is possibly induced by a microbial trigger and stimulates autoimmunity . The thrγ) can overpass the type I IFN signature (represented by the IFN-α/β cascade) [γ, secreted by T lymphocytes, natural killer cells and macrophages, plays an antimicrobial role, and its increased levels during lymphomagenesis may represent the attempt of the immune system to counteract a chronic infection.It is worth noting that the association with IRF5 highlights its presumable role in the pathogenesis of SS insofar as this mediator is involved in both viral infections and lymphomagenesis. IRF5 binds cellular DNA to its amino-terminal domain and regulates the transcription of some of the genes involved in inflammation, such as type I IFNs and other cytokines including interleukin-17 (IL-17). Some studies have shown that IRF5 may induce a permissive background to latent viral infections such as those due to EBV and favours the process of B cell transformation into malignant clones , whereascascade) . IFN-γ, BAFF gene were associated to an incremental risk of developing lymphoma in SS patients, with the rs9514828 T allele in the BAFF gene promoter conferring a high risk compared to healthy controls [BAFF-R gene was associated with SS and SS-associated MALT lymphoma, especially in younger patients [Once the inflammatory cascade has been triggered, glandular epithelial cells undergo apoptotic and proinflammatory processes that recruit cells belonging to both innate and acquired immunity. Histological studies of salivary glands have demonstrated the presence of infiltrates of macrophages, dendritic cells, natural killer cells, and B and T lymphocytes. B lymphocytes are the main protagonists as they are responsible for cytokine release, antigen presentation, and the production of autoantibodies in a T cell-dependent or T cell-independent manner. The release of large amounts of antibodies in the circulation leads to the deposition of immune complexes and the development of systemic complications in 15% of cases . At the controls . A similpatients .Immune system cells may contribute to counteract the escape of malignant clones. For example, the presence of autoreactive T cells in the autoimmune infiltrates of the minor salivary glands is usually associated with a better prognosis and a limited risk of lymphoma. T cells can be divided into cluster of differentiation 4+ (CD4+) and CD8+ cells, with the latter being more numerous in the most aggressive forms of SS that are usually associated with lymphoma risk. A multiomics study of whole-blood transcriptomes, serum proteins, and peripheral immunophenotypes in 30 Japanese SS patients and 30 controls revealed a CD8+ lymphocyte signature associated with the expression of a disintegrin and metalloprotease (ADAM), thus indicating an activated phenotype . CD8+ lyAmong the CD4+ lymphocytes, T helper 17 (Th17) cells have been associated with most severe pictures of glandular inflammation and are known to be highly pathogenic in other autoimmune diseases such as RA and spondyloarthritides . They arAlthough their exact role in lymphomagenesis is still controversial, increased percentages of circulating Th17 lymphocytes have been reported in patients with B cell lymphoma and are inversely related to treatment response . AccordiIn addition to acquired immunity, the activation of innate immune system cells may further amplify local and systemic inflammation and provide a direct link between infections and autoimmunity or lymphomagenesis. Toll-like receptors (TLRs) are abundantly expressed in cells belonging to the innate immune system and may cross-recognize molecules from damaged cells, including cancer cells (damage-associated molecular patterns (DAMPs)) and pathogens (pathogen-associated molecular patterns (PAMPs)). In SS patients, the stimulation of TLR2 and TLR4 on the plasma membrane of peripheral blood mononuclear cells (PBMCs) by bacterial compounds such as lipopolysaccharide (LPS) induces the production of IL-17, whose effects on B lymphocytes have been discussed above. Salivary epithelial gland cells recognize viral genome by means of intracellular TLR3 and induce the expression of CD40, intercellular adhesion molecule 1 (ICAM-1), MHC class I, and BAFF, which promote the activation and proliferation of B cells . The actAlu sequences or long interspersed elements (LINEs), which are usually sites of retroviral integration, whereas up to 40% involved 5′—C—phosphate—G—3′ (CpG) islands that are usually associated with the promoter region. Altorok et al. described different patterns of methylation in peripheral CD4+ T cells in 11 Caucasian patients with pSS and controls [A number of studies have demonstrated that patients with SS and other autoimmune diseases have an impaired epigenetic profile consisting of aberrant DNA methylation, histone deacetylation, and/or the production of noncoding micro-RNA . Miceli-controls . They focontrols . TherefoκB) and activator protein-1 (AP-1) pathway and the NLR family pyrin domain-containing 3 (NLRP3) inflammasome [Other authors found nearly 40% homology in the methylation patterns of genes taken from salivary gland epithelial cells and peripheral B and T lymphocytes obtained from 16 SS patients and 4 controls  but demoammasome . Inflammammasome , 36. Theammasome .Finally, other authors have described the hypomethylation of the genes involved in the IFN pathway in whole blood, CD19+ B lymphocytes, and minor salivary gland biopsies of pSS patients . It is nInterestingly, all of these studies agree on the hyperexpression of interferon-induced protein 44-like (IFI44L) in the B and T lymphocytes and whole blood of SS patients: this protein prevents the replication of various human viruses, including HCV, yellow fever virus, West Nile virus, chikungunya virus, and human immunodeficiency virus-1 , thus suMTHFR c.677C>T T allele and a reduced expression of the MTHFR 1298 A>C C allele compared to healthy controls, whereas no significant differences in MTHFR gene polymorphisms emerged when SS patients with MALT lymphoma were considered [The methylation of CpG islands is the main mechanism underlying the inactivation of the X chromosome in females. As SS is prevalent in women, impaired methylation of the X chromosome  has been suggested and demonstrated in salivary gland epithelial cells of SS patients . The X cnsidered . These gHelicobacter pylori seem to modulate the expression of some micro-RNAs controlling cell proliferation and survival. Floch et al. have demonstrated in a gastric MALT lymphoma mouse model that chronic Helicobacter pylori infection may induce the overexpression of micro-RNAs 21a, 135b, 142a, 150, and 155, which prevents the transcription of the gene coding for the proapoptotic protein tumor protein P53-inducible nuclear protein 1 (TP53INP1) [In addition to DNA methylation, aberrant micro-RNA expression has also been described in the pathogenesis of SS . Micro-RP53INP1) . Some ofP53INP1) . Viral mper se that is capable of interacting with host cells and guiding the differentiation of the immune system [phyla, lies at the basis of many autoimmune diseases as it may elicit sterile inflammation and prime the innate and acquired immune system [The human microbiome, which consists of 100 trillion commensal bacteria, protozoa, fungi, and viruses living inside and on the human body, is now widely considered an independent organ e system , and thie system , 58. Alte system . Pathogee system .Staphylococcus aureus and Escherichia coli, and as a result of molecular mimicry, these can cross-react against mitochondrial self-antigens, which may explain their symptoms of fatigue [Enterobacteriaceae over Bifidobacteriaceae that is finally responsible for autoimmunity [Various studies of SS patients and animal models have demonstrated dysbiosis in the gut and oral mucosa . Patient fatigue . A conti fatigue , althougimmunity .Viral infections  are quite frequent in SS patients. These viruses share the ability to integrate themselves into the host cell genome and use its transcriptional machinery to change latent to lytic infection , 64. ThiRetroviruses can insert themselves into host cell DNA, modulate the transcription of cellular genes, or generate aberrant transcripts that activate the innate immune response. Infections due to human immunodeficiency virus-1 (HIV-1) and type 1 human T lymphotropic virus can induce the onset of sicca syndrome, and studies of animal models and patients with SS have shown the presence of retroviral antigens or genomic sequences in salivary glands as well as serum antibodies reacting against retroviral Gag proteins .In addition to viral infections, the human virome (which mainly consists of bacteriophages) may induce bacterial dysbiosis, which is associated with the development of autoimmune diseases such as inflammatory bowel diseases or type I diabetes . HoweverAlu). Most cannot retrotranscribe but they can affect the transcription of genes adjacent to their insertional site. Cells are usually capable of distinguishing exogenous nucleic acids and their own genome on the basis of the molecular structure (length or nucleotide composition), but there is some evidence indicating that endogenous Alu retroelements can form complexes with cellular ribonucleoproteins such as Ro60 and activate TLR pathways [κB pathway, and generate a type I IFN signature [The cellular genome also contains retroelements or latent viral insertions that may activate inflammasomes . These epathways  and SINEpathways . Interespathways . It has pathways , 75 and pathways . Accordiignature . The reaignature . HoweverdimCD138+ plasmablasts following H1N1 influenza vaccination as a result of hyperactive B cells [It is still unclear whether the epigenetic changes induced by chronic latent infections can trigger the development of SS and SS-associated lymphomas in genetically predisposed subjects. Pathogenic and sterile infections may both contribute to the disease by chronically stimulating B lymphocyte clones. Patients with pSS produce polyclonal antibodies and have increased levels of C19 B cells . Like ot B cells . In addi B cells .κB, which promotes the survival and activation of B cells. It is worth noting that the TNFAIP3 somatic mutation is found in approximately 28% of all MALT lymphomas and the dysregulation of this gene has also been associated with SS in GWAS [The most frequent SS-associated lymphoma is MALT lymphoma , but SS  in GWAS –9, 83. O in GWAS .+/+ mice carrying insertions at the heavy and light chains of autoantibody 564, which reacts against nucleic acids and nucleoproteins, has shown that lymphomagenesis may be related to autoimmunity and that both may be prevented by the antibiotic treatment of gut microbiota [An interesting experiment involving homozygous 564Igicrobiota . More spChlamydophila psittaci, Campylobacter jejuni, and Helicobacter pylori and they can be sometimes eradicated by antibiotic therapy in the earlier phases of development [de novo onset or relapse of cancer in SLE patients [There is much evidence that MALT lymphomas may follow infections due to elopment . Bacteripatients .A fascinating alternative to chronic infectious stimulation of B cells is the possibility of alterations in gene transcription due to transposable retroviral elements or latent virus infections. Latent EBV transcripts (including EBNAs and LMPs) epigenetically regulate the transcription of viral oncoproteins by means of CpG methylation, histone deacetylation, micro-RNA pairing, or super enhancer activation , and thecis, by transcribing the HERV proteins responsible for the formation of autoantigens or inducing RER stress, and, finally, by cooperating with infections due to common viruses such as EBV or influenza virus [Emv2, which may have acquired infectiousness following the recombination of genomic strands.Human endogen retroviruses (HERVs) represent the “ghosts” of long-latent viral infections whose fully integrated genome accounts for 8% of human DNA. It has been hypothesised that HERVs favour disease onset in a pathogenic model of multiple sclerosis (MS) by inducing or repressing the transcription of the MS causative gene in za virus . HERVs aza virus . The autCancer cells can escape immunosurveillance as a result of T cell exhaustion and the increased expression of the immune checkpoints that prevent immune cell activation (programmed death (PD-1) or cytotoxic T lymphocyte antigen 4 (CTLA4)). Cancer patients treated with the new antitumoral agents known as checkpoint inhibitors may develop autoimmune symptoms. SS has been reported in four patients treated with ipilimumab and nivolumab, although it is interesting to note that none of the patients was positive for anti-Ro/SSA antibodies, thus suggesting a different pathogenesis . Latent Like that of other autoimmune diseases, the pathogenesis of SS is due to interactions between a favourable genetic background and an environmental trigger such as infections or dysbiosis. Microorganisms may induce epigenetic modifications in target cells and tune their transcriptome to generate an activated or transformed phenotype. The establishment of lymphoma in more than 15% of SS patients may be the end result of a combination of genetics, epigenetics, dysbiosis, or latent infections. Interestingly, there is increasing evidence that retroelements integrated in cell DNA participate in the process of lymphomagenesis and autoimmunity, perhaps by modulating the expression of key genes; however, there is still a lack of studies specifically investigating their precise role in the pathogenesis of SS and SS-associated B cell lymphoma.


Identifying putative biomarkers of clinical outcomes in cancer is crucial for successful enrichment, and for the selection of patients who are the most likely to benefit from a specific therapeutic approach. Indeed, current research in personalized cancer therapy focuses on the possibility of identifying biomarkers that predict prognosis, sensitivity or resistance to therapies. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor gene that regulates several crucial cell functions such as proliferation, survival, genomic stability and cell motility through both enzymatic and non-enzymatic activities and phosphatidylinositol 3-kinase (PI3K)-dependent and -independent mechanisms. Despite its undisputed role as a tumor suppressor, assessment of PTEN status in sporadic human tumors has yet to provide clinically robust prognostic, predictive or therapeutic information. This is possibly due to the exceptionally complex regulation of PTEN function, which involves genetic, transcriptional, post-transcriptional and post-translational events. This review shows a brief summary of the regulation and function of PTEN and discusses its controversial aspects as a prognostic/predictive biomarker. Cancer is a very complex and dynamic disease, characterized by both genetic and microenvironmental features. Decades of genetic studies have allowed the identification of a landscape of somatic mutations in a large collection of genes involved in tumor development. Recently, Sondka et al. described 719 cancer-associated genes in humans: 574 genes were classified in the catalogue of somatic mutations in cancer Tier 1 genes (genes whose mutation is associated with the promotion of neoplastic transformation) and 145 in Tier 2 genes  .The identification of new biomarkers and the development of gene expression signatures are necessary to improve early diagnoses and accurate prognoses, as well as to provide an opportunity to better match the most effective drugs with the molecular characteristics of each individual patient. Studies over the years have clearly indicated that prognostic and predictive biomarkers are often molecules involved in the regulation of cellular mechanisms, including proliferation, apoptosis, angiogenesis, metastasis and in therapeutic resistance . AccumulGermline mutations of the PTEN gene cause the well-known PTEN hamartoma tumor syndromes. These syndromes, which are molecularly characterized, include Cowden, Proteus, Proteus-like and Bannayan–Riley–Ruvalcaba syndromes . PTEN geMoreover, loss of PTEN tumor suppressor activity may represent a cancer vulnerability, which could be exploited therapeutically. Indeed, our group has recently shown that combined mitogen-activated protein kinase (MAPK) and PI3K inhibition is selectively synergistic in tumors with PTEN loss. Therefore, the recent failure of mitogen-activated protein kinase kinase (MEK)-/AKT-inhibition combination in advanced pancreatic cancer could have been predicted preclinically. All this evidence suggests an urgent need to devise more efficient translational strategies to bring new therapies to the patients’ bedsides in pancreatic and other cancers ,12,13.Despite its undisputed role as a tumor suppressor, assessment of PTEN status in sporadic human tumors has yet to provide clinically robust prognostic, predictive or therapeutic information. This is possibly due to the exceptionally complex regulation of PTEN function, which includes, for example, transcriptional, post-transcriptional and post-translation mechanisms. Thus, loss of PTEN function bears a great, but yet unfulfilled, potential as a prognostic and predictive biomarker to prospectively select groups of patients at the highest chance of benefit for specific therapeutic interventions. In this review, we summarize recent advances in PTEN regulation and function, specifically focusing on relationships with cancer clinicopathological features and on factors that could make PTEN a new biomarker for diagnosis, prognosis and prediction of response in cancer therapy.PTEN is a tumor suppressor gene mapping to chromosomal region 10q23 and encoding for a 403-amino acid protein that plays a pivotal role in signal transduction  14]. . 14]. Loss of PTEN function can occur through a mix of genetic/epigenetic mechanisms including point mutations, chromosomal deletions, promoter hypermethylation and post-translational modifications, leading to a wide spectrum of human diseases . FurtherThe PTEN gene contains 9 exons, which harbor many variations at the germline level. Even if a lot of those are found in exon 5 (which encodes for the phosphatase core motif) and the other relevant variations are clustered mainly in exon 7 and 8, they are scattered along the whole gene . PTEN muTranscriptional regulation of PTEN occurs through both epigenetic and transcriptional mechanisms. Epigenetic modulation of PTEN expression leads to the silencing of the gene through the presence of hypermethylated CpG islands. This mechanism of silencing is observed in numerous cancers , hepatocellular carcinoma, melanoma, breast and thyroid cancers) ,19. PTENα and the unspliced nuclear localized PTENpg1 asRNA α suppress PTEN transcription, whereas sense PTENpg1 promotes PTEN transcription. Sense PTENpg1 binds PTENpg1 asRNA β, thereby increasing the activity of sense PTENpg1. Sense PTENpg1 binds miRNA targeting of PTEN with its 3′ UTR, thereby increasing PTEN messenger RNA stability and the consequent amounts of the protein [MicroRNAs (miRNAs) are critical regulators of PTEN abundance at the post-transcriptional level. Different miRNAs can increase or decrease PTEN levels—including those derived from miRNA precursors containing a single hairpin structure , as well as those with a polycistronic structure —thus playing a role as a tumor suppressor or tumor promoter, respectively [ protein .In addition, numerous post-translational modifications  modify the properties of PTEN as a tumor suppressor and impact PTEN localization in the cell ,25,26. MIncreasing evidence also shows that PTEN can interact with both itself and other protein partners, modulating its activity . PandolfPTEN acts as a non-redundant negative regulator of the PI3K/AKT pathway with a specificity for both protein and lipid substrates. The two main functional domains identifiable in the PTEN structure are the phosphatase domain and the C2 domain. While the phosphatase domain is responsible for enzymatic activity of the tumor suppressor, the C2 domain allows its membrane association by promoting the positioning of the catalytic domain on the plasma membrane . C-termiPTEN also has several lipid- and phosphatase-independent functions involved in cell-cycle regulation, migration and tumor progression ,48. IndeIn addition, distinct functions of PTEN are associated with the extracellular environment through its secretion and export. Cellular non-autonomous effects of PTEN are mediated by two main mechanisms, direct (through the release from the cell of a membrane-permeable PTEN isoform (PTEN-L)) and indirect (through the release of PTEN into exosomes) . PTEN-L Recent evidence has also highlighted a potential role of PTEN in regulating tumor microenvironment (TME) features. Experiments in mice demonstrated that deletion of PTEN in fibroblasts creates a tumor-permissive stroma in mammary gland tumors, with a consequent recruitment of innate immunity cells, remodeling of the extracellular matrix and tumor vasculature, thus increasing malignancy . TME remSeveral studies have shown that the PI3K/AKT pathway can modulate immune cell activities, thereby impacting the potential effectiveness of cancer immunotherapy . Among tOver the last decades, a wealth of prognostic and/or predictive biomarkers have been studied with the aim to more accurately predict outcomes of individual patients, on the one hand, and to improve treatment response on the other. A handful of such predictive biomarkers have proven so crucial in the cancer drug development process that specific tests to accurately measure relevant biomarkers have been approved by regulatory agencies together with their matching drugs, so that selected drugs can be prescribed only in biomarker-positive patients (companion diagnostics) ,70,71,72PTEN loss has been found to occur in approximately 20% of prostate tumors, and its mutation or deletion is currently recognized as one of the critical factors in hormone-naïve and castration-resistant prostate cancer . Recent Given its role in genomic stability, PTEN loss also correlates with higher levels of chromosome instability and increased aneuploidy in prostate cancer. Viadotto et al. recently demonstrated that the mechanisms of PTEN deletion are not random, but fall into five distinct classes with a conserved clustering of somatic copy number alterations and specific acquired features . PreclinQue et al. have recently carried out a meta-analysis identifying PTEN loss as a prognostic factor for worse overall survival (OS) in patients affected with kidney cancer due its role in increasing aggressiveness and the progression of this type of tumor . Tang etSeveral data have shown that PTEN mutations are associated with pancreatic cancer development in animal models and that, even if its mutation is rarely identified in pancreatic cancer, PTEN protein expression is often low or completely absent ,83,84. MCRC is one of the main causes of cancer death and is often associated with the mutation of oncogenes and tumor suppressors downstream the epidermal growth factor receptor (EGFR) such as BRAF, Kirsten rat sarcoma (KRAS), PI3KCA and PTEN . CRCs caSomatic PTEN mutations are rare (around 5%) in sporadic breast carcinoma; however, the frequency of PTEN gene loss is approximately 30%–40%, and accounts for approximately 20%–25% of HER2-positive breast cancers ,95. IndeEC is one of the most common female neoplasia. PTEN mutations are found in approximately 25% of cases of hyperplasia and up to 80% of endometrioid EC (EEC) cases ,100. In Glioma represents the most frequent (around 40%) brain neoplasm of the central nervous system, displaying a very high incidence of PTEN gene mutations (from 25% to 40% of glioma cases). Given the key role of PTEN activity in physiological mechanisms of the development of brain cells and of the maintenance of cerebral homeostasis, its activity has also been investigated in processes such as tumor progression and grade of glioma malignancy ,105. ConPTEN gene alteration is not among the most frequent mutational events in melanoma (10%), but PTEN loss co-occurs with BRAF activating mutations  in 44% of BRAF mutant melanoma . DespiteThe PI3K/mammalian target of rapamycin (mTOR) pathway is one of the most frequently deregulated pathways in leukemia. Even though PTEN mutations are not frequently observed in myeloid malignancies (1%), PTEN protein is often inactivated in acute myeloid leukemia (AML) and chronic myeloid leukemia . Cheong The inactivation of the PTEN gene also occurs in many cases of pediatric and adult T cell acute lymphoblastic leukemia. Paganin et al. recently demonstrated that PTEN mutations, alone or in combination with NOTCH1 mutations, might identify patients with a higher probability of relapsing . NeverthIn order to present the current status of PTEN loss as a prognostic biomarker in currently available genomic and clinical data, we performed an automated survival analysis on all 31 datasets of The Cancer Genome Atlas (TCGA) through the cBioPortal R package cancer genomics data server at the time of the writing  9,10,11,1110,117p < 0.05). Overall, among 124 tests of survival separations for 31 datasets and 4 conditions (PTEN loss/del and OS/DFS), 13 did not have available clinical data and only a subset of 26 combinations resulted significantly in separating survival curves . Indeed, even though trastuzumab is highly effective in patients, many HER2- positive tumors become resistant to treatment and, therefore, it is necessary to identify other biomarkers . DiffereMonoclonal antibodies for EGFRs are also clinically used for metastatic CRC (mCRC), and several groups demonstrated that PTEN expression also predicts clinical outcome in this histotype. Indeed, Frattini’s group showed that PTEN-loss mCRC patients do not benefit from cetuximab treatment. Two years later, Loupakis et al. demonstrated that PTEN loss in metastases could also be predictive for the combined treatment outcome of cetuximab plus irinotecan ,131. ThePTEN status could be a predictor not only for targeted therapies plus chemotherapy, but also of different targeted therapy combination outcomes. Chung et al. recently showed that the dual targeting of MEK and PI3K/AKT signaling does not exhibit clinical benefits in unselected PDAC patients . We demoPTEN is a haploinsufficient tumor suppressor that regulates several cell functions  and it is mutated in several types of cancer. PTEN displays a very complex mode of regulation that makes identifying clinical situations in which loss of PTEN activity is a major driving force particularly cumbersome. To date, there is no clinically validated detection assay to analyze PTEN expression and function, but an increasing number of studies have highlighted its potential role as a prognostic and predictive biomarker in cancer. The development of a functional “signature” of loss of PTEN activity would be the most innovative approach, in order to overcome the limitation of functional PTEN detection and to identify genes, miRNAs or proteins that could directly recognize defective PTEN function.


Three-dimensional (3D) and Four-dimensional (4D) printing emerged as the next generation of fabrication techniques, spanning across various research areas, such as engineering, chemistry, biology, computer science, and materials science. Three-dimensional printing enables the fabrication of complex forms with high precision, through a layer-by-layer addition of different materials. Use of intelligent materials which change shape or color, produce an electrical current, become bioactive, or perform an intended function in response to an external stimulus, paves the way for the production of dynamic 3D structures, which is now called 4D printing. 3D and 4D printing techniques have great potential in the production of scaffolds to be applied in tissue engineering, especially in constructing patient specific scaffolds. Furthermore, physical and chemical guidance cues can be printed with these methods to improve the extent and rate of targeted tissue regeneration. This review presents a comprehensive survey of 3D and 4D printing methods, and the advantage of their use in tissue regeneration over other scaffold production approaches. Tissues are dynamic structures constituted by multiple cell types, an extracellular matrix (ECM) and a variety of signaling molecules. The extracellular matrix (ECM) is a crucial component of the cellular microenvironment and forms a complex three-dimensional network  printing, also known as additive manufacturing or rapid prototyping, plays an important role in tissue engineering applications where the goal is to produce scaffolds to repair or replace damaged tissues and organs. Three-dimensional printing uses a bottom-up approach. Production is guided by a computer model which uses cross-sectional data obtained by slicing magnetic resonance (MR) or digital image of the defect area. Thus, production in a layer-by-layer fashion is possible using this technique, with high structural complexity, especially for patient-specific implants  was developed and patented by Scott Crump in the late 1980s and is one of the most commonly used rapid prototyping techniques. This technology has been used in a broad range of applications including automotive, aerospace, model production for visualization, design verification, and biomedicine  is an additive manufacturing (AM) technique which was developed and patented by Carl Deckard and Joe Beaman in 1989 Deckard,  Figure . After tSLS offers the advantage of fabricating large and complex scaffolds. Another advantage is that SLS does not require any support structures during the production process, since the sintered object is located in a solid powder bed and a sacrificial layer is not needed  is based on selective polymerization of a liquid, photosensitive resin by a light source, such as UV light or a laser  can be used. In the laser-based method, a laser beam which is controlled by a computer directly writes an object in a bottom-up way  Skoog e. The reqSLA offers many advantages over the other techniques. First, each layer is printed at the same time when multiple objects are being printed, and total printing time is only based on the structure thickness. This significantly decreases printing time , a traditional scaffold production technique frequently adopted in tissue engineering applications, is based on the uniaxial elongation of a viscoelastic jet of a polymer solution or melt under high voltage  or mechanical (screw or piston) systems. In the pneumatic system, bioink is extruded from the nozzle or needle as an uninterrupted cylindrical filament by applying continuous air pressure instead of single droplets. This provides high structural integrity to the product  is another bioprinting system which consists of a pulsed laser source, a donor layer, and a receiving substrate. The principle of LAB is that, bioink is placed below a ribbon which also contains a thin, energy absorbing layer. The ribbon is placed parallel to the receiver. The pulsed laser source is focused on the laser absorbing-layer and this generates a vapor bubble. This bubble creates a pressure to deform the bioink and forms droplets. These cell loaded hydrogel droplets are propelled toward the receiver where they are collected and crosslinked , also known as fused filament fabrication (FFF), and is the simplest 3D printing method. Polymeric filaments must have a certain diameter to fit the heating and extruding head of the printer. Quite a number of commercial filaments, such as acrylonitrile butadiene styrene (ABS), and poly(lactic acid) (PLA) are available on the market. ABS is the most preferred 3D printing material for FDM applications because of its relatively low glass transition temperature and absence of crystallites due to it being an amorphous polymer. These properties enhance accuracy in printing and dimensional stability of the product because the shrinkage ratio during the cooling step is very small. However, the use of ABS filaments in tissue engineering is limited due to its non-biodegradable and non-biocompatible nature  and selective laser sintering (SLS).Poly(caprolactone) (PCL) is a common polymeric material utilized by FDM and SLS for tissue engineering applications because of its low melting temperature (55–60°C), excellent viscoelastic and rheological properties in addition to its a biodegradability and biocompatibility. It is approved by the FDA (Food and Drug Administration of USA) for certain medical applications  is one of several commonly used PLGA copolymers and is another synthetic thermoplastic polymer approved by the FDA for clinical use. It was used in FDM applications to fabricate scaffolds due to its processability and high mechanical strength  and polybutylene terephthalate (PBT), are thermoplastic elastomers employed in FDM applications. These block copolymers display excellent properties, such as toughness and elasticity, biocompatibility and easy processability. However, PEOT/PBT has been less studied compared to PCL and PLA because it requires an extremely high melting point (225°C)  is a semi-crystalline thermoplastic polymer which has extensively been utilized in SLS. PEEK has a high elastic modulus similar to cortical bone, making it a good alternative to metal implants Mazzoli, . It is aPoly (PVA), and blends of PVA and HAP have been studied as other powder-based materials for SLS for use in cartilage and bone tissue engineering , printable , and robust   and components of the extracellular matrix (ECM)   are generally used as resins in stereolithography (SLA) Du, . PEG is Poly(propylene fumarate) (PPF) is also a photo-crosslinkable polymer utilized in stereolithography and overcomes some limitations of synthetic hydrogels, such as lower mechanical strength and a lack of biodegradability. PPF polymer is generally mixed with a photoinitiator and a solvent like diethyl fumarate (DEF). Printability and mechanical properties of the scaffold depend on the PPF/DEF ratio  materials are able to self-transform into a predefined shape or exert a predefined function depending on the stimuli present in the microenvironment; these processes are regarded as “4D printing” Tibbits, . Four-diFive main factors influence the process of 4D printing: (i) type of additive manufacturing process, (ii) type of responsive material, (iii) type of stimulus, (iv) interaction mechanism between stimulus and the material, and (v) mathematical modeling of the material transformation.Additive manufacturing process, as in 3D printing, realizes the spatial geometry provided by the digital information produced in computer aided design/manufacturing (CAD/CAM) programs. Many additive manufacturing processes that are commonly used, such as fused deposition modeling (FDM) .An ongoing debate about 4D printing is whether gradual degradation of 3D printed constructs can be categorized as a time-dependent 4D effect  physical stimuli and (ii) chemical stimuli. Temperature responsive, photo responsive, and magneto-responsive polymers fall under those that respond to physical stimuli, while pH and humidity responsive polymers are classified under responsiveness to chemical stimuli.Temperature responsive polymers are among the most frequently used materials in 4D printing applications especially in the tissue engineering field where a change in temperature can be easily controlled and applied in a non-invasive manner. Many applications exploit the human body temperature, 37°C, to trigger the desired response of some materials. The two most common classes of temperature responsive polymers used in 4D printing applications are (i) shape memory polymers, and (ii) responsive polymer solutions  and the other is the switching segment with intermediate glass transition temperature  or melting temperature (Tm) , a temporary shape is formed. At this stage the elastic segment cannot return to its original form even after the removal of applied constraints. The driving energy for the shape change effect of the polymer is the elastic spring energy contained within this segment. When the polymer is heated above Tg, 2 again, the elastic segment is able to drive the shape change effect that transforms the polymer back to the original permanent shape  that have temperature responsiveness are thermoplastic elastomers consisting of two distinct components, one is the elastic segment with a high glass transition temperature (Ture (Tm) . When deShape memory polymers have some advantages and drawbacks compared to their metal and ceramic counterparts. The advantages include low density, low cost, ease of shape manipulation and good control over recovery temperature, high strain recovery, and physical and chemical modification ability to achieve desired properties . As drawbacks compared to metals and ceramics they have lower strength, elastic modulus and processing temperatures.Some examples of shape memory polymers used in 4D printed tissue engineering applications are poly(ε-caprolactone) dimethacrylate (PCLDMA)  (PNIPAM)  (PNVC) -modified poly(acrylic acid) (PAA)  or covalently immobilized, these magnetic nanoparticles introduce responsiveness to a magnetic field  which consist of magnetic elements, such as iron (Fe), cobalt (Co), nickel (Ni), or their oxides  nanoparticles containing mesoporous bioactive glass/poly(ε-caprolactone) (Fe3O4/MBG/PCL) oxide  (PGA), poly(histidine) (PHIS), poly(acrylic acid) (PAA)  and Tm which makes it a very good compound for fused deposition modeling  isolated from bone marrow or adipose tissue are the most frequently used ones  organization due to the anisotropic orientation of the nerve fibers. Nerve guides are used to bring the proximal and the distal ends of a damaged nerve after an injury occurs. They can also be fabricated by 3D printing to provide patient-specific constructs with a complex inner architecture. Various types of additive manufacturing (AM), such as ink jet printing, stereolithography (SLA), fused deposition modeling (FDM) and bioprinting are frequently used in order to produce nerve tissue engineering products. Fibrin  are incorporated into the constructs, however, glial cells, primary cortical neurons, astrocytes, Schwann cells (SCs), bone marrow stem cells (BMSCs), and retinal ganglion cells (RGCs) were also used in nerve regeneration studies  and Schwann cells (SCs), was printed and tested in a sciatic nerve injury model  and 7 (83%) in the culture medium  to introduce highly aligned and reproducible fibrous structures into the 3D printed scaffolds. NFES technology provides precise control over the orientation of the fibers. Therefore, it is generally used in the development of anisotropic tissues, such as the nerve, cornea, and muscle  nanoparticles containing mesoporous bioactive glass/poly(ε-caprolactone) (Fe3O4/MBG/PCL)  (PEGDA)/Fe3O4 (De Santis et al., in vitro studies of the 4D printed scaffolds (Pati et al., in vivo studies since it is a relatively new technique. Tissue engineering applications of 4D printing are summarized in Like in 3D printing applications, SLA (Raman et al., Three-dimensional printing is becoming an indispensable tool in the production of devices and systems in biomaterials and tissue engineering areas. It changed the face of the biomaterials world with the production of patient specific devices that have the required shape and organization. Stimuli responsive materials, such as metals and polymers have been in use in the biomedical field, and the combination of material and responsiveness in a biomedical device creates 4D printing which introduces highly useful, viable, dynamic, and responsive systems in tissue engineering applications. As it is, 3D and 4D printing methods is still keeping researchers busy in their quest for producing novel biomaterials and biomedical devices. The current types of stimuli to which the materials are responsive to are quite well-known but is, unfortunately, limited. So, the development of different materials with multi-sensitivities for use in the enhancement of the dynamic nature of devices is still a challenging issue.DT, TD, and AA wrote the first draft. DY, NH, and VH edited, revised, and finalized the text.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.