Despite all the recent pharmacological advances and the introduction of targeted therapies in clinical practice, cancer still remains one of the leading cause of death, accounting for 10 million deaths per year, based on the most recent reports . NowadayRT represents a fundamental component of multimodality approaches for the treatment of many types of cancer. Approximately, the 50–60% of all cancer patients are undergoing RT through several modalities, such as internal or external RT, either alone or in combination with other treatment regimens . Improvements in RT have been made in regard to the reach of higher technological levels, which allow an optimal dose distribution and conformational treatment customization. Research in both radiobiology and medical physics is focused on the evaluation of new hypofractionated or combined RT protocols, in order to increase effectiveness in cohorts of patients . HoweverIndeed, tumors can be classified as radioresistant and radiosensitive and such balance is not only dependent on the nature of the radiation used to treat the tumor bulk, but also by different complex factors, increasingly highlighted by radiobiology studies . They inIn this scenario, the role of cancer research is to identify specific molecular traits of neoplasms, in order to design successful clinical treatments. Therefore, in the era of target therapies, the identification of cancer biomarkers is required to drive therapeutic decisions also between different RT modalities and schedules. The use of omics sciences provides new high throughput tools to monitor tumor progression and to predict radiation response both in tumor and healthy tissue ,10,11.This Special Issue aims to describe the state of the art about the role of RT in cancer and its contribution for personalized medicine.More specifically, Musielak and colleagues collected in a review paper the advancement in regard to the use of proton therapy (PT) in minimizing the toxicity of breast cancer (BC) RT. As is already known, PT is considered a valuable alternative to conventional RT modalities for its ballistic precision and capability to spare the healthy tissue surrounding the tumor bulk. When considering BC, one of the main side effects of RT is cardiotoxicity. Hence, the preservation of cardiac tissue represents a main challenge and authors described a thorough analysis of literature regarding issues related to RT-induced cardiac toxicity .In line with this topic, Cunningham et al. studied the impact of breast size on dosimetry, comparing PT versus conventional X-ray RT for BC, with the use of two different innovative RT techniques, such as hybrid inverse-planned intensity modulated X-ray radiotherapy (h-IMRT) and intensity modulated proton therapy (IMPT) .In order to underline radioresponse biomarkers for glioblastoma multiforme (GBM), Bravatà et al., performed a transcriptomic study by whole-genome cDNA microarray on the U87 GBM cell line following PT treatment in hypoxic conditions . HypoxiaIn order to depict the genetic basis of radiation-induced late skin toxicity, Cargnin et al. carried out a targeted next-generation sequencing study, in breast cancer patients, for the identification of genetic predictors of healthy skin response to RT, as well as cardiotoxicity; in fact, RT induces detrimental side effects to skin tissue .Finally, Danieli et al., provided a thorough description about the state of the art of all those strategies adopted in personalized dosimetry aimed at targeted radiation therapy (TRT) for the treatment of different types of cancer .


This review offers a discussion on how energy storage deployment advances equitable outcomes for the power system. It catalogues the four tenets of the energy justice concept—distributive, recognition, procedural, and restorative—and shows how they relate to inequities in energy affordability, availability, due process, sustainability, and responsibility.Energy storage systems have been deployed to support grid reliability and renewable resource integration, but there is additional emerging value in considering the connections between energy storage applications and equity challenges in the power system. Through a thorough review of the energy justice and energy transitions literature, this paper offers the equity dimensions of storage project design and implementations.Emerging energy programs and projects are utilizing energy storage in pursuit of improved equity outcomes. Future research and policy design should integrate energy justice principles to align storage penetration with desired equity outcomes. Public interest and regulatory efforts that target the climate crisis and advance an energy transition that leaves no one behind have started to increase at all levels. For example, at the federal level, the House Select Committee on the Climate Crisis offered a climate crisis action plan that sets a goal of an economy-wide net zero emissions by 2050 and the reduction of pollution in environmental justice (EJ) communities . State-lA key enabler in the future of this decarbonized and renewable energy (RE)–dominated power system is the integration of energy storage. Energy storage technologies—pumped hydropower, battery storage, flywheel—mitigate the non-dispatchable production of RE by storing the energy output for use when needed. Recently, large-scale battery storage has seen an increasing penetration in the power grid . Energy A valuable, but less examined, benefit of energy storage is its ability to contribute to the just energy transition. The concept of just energy transition alludes to a process of adding justice and equity concerns in the energy transition from high-carbon energy sources to a renewable energy–dominated resource portfolio . SpecifiThis paper assesses the equity-storage linkage to identify the equity implications of further integrating storage in the power system. The next section starts by providing a discussion of the existing power system inequities. Then, the paper offers the four tenets of energy justice—distributive, recognition, procedural, and restorative—to examine the role of energy storage in advancing a just energy transition. Within the broader four justice tenets, the paper relies on the affordability, availability, due process, sustainability, and responsibility energy justice principles to help identify the concerns or inequities of the energy system. In this paper, the tenets and principles are linked as follows: distributive justice is assessed through the affordability and availability principles; recognition and procedural justices are assessed through the due process principle; and restorative justice is assessed through the sustainability and responsibility principles. In doing so, the paper examines the temporal, economic, socio-political, geographic, and technological equity dimensions of the power system and shows where and how storage fits in the discussion. This review paper concludes with a recommendation of future research and practice areas to embed storage as an equity enabling technology.The inequities of the power system are usually manifested in two ways: the lack of access to the energy transition technology opportunities and the inequitable distribution of benefits –11. The On the systemic and institutional level, the power system inequities relate to the opportunity to participate in decision-making processes , 20. TheEnergy equity refers to the distribution of costs and benefits of the energy power system. The energy literature engages with the issue of equity through the concept of energy justice . The latThe current energy justice scholarship summarizes these principles under the four core tenets of energy justice: distributive justice, recognition justice, procedural justice, and restorative justice , 24, 25.For these reasons, the clean energy transition may deepen certain existing inequitable outcomes on different socio-economic groups, racial and ethnic minorities, genders, geographics, and other demographics ••, 29. EAvailability and affordability of energy systems and services are key to realizing distributive equity ••. AvailIn the USA, low-income households spend a high percentage of their income (approximately three times higher) on energy cost compared to their mid-high income household counterparts •. This iAnother way to look at equity is by examining the accessibility of energy technologies across the socio-economic spectrum . Tax creAs energy storage solutions become downscaled modular and available to energy consumers on a behind-the-meter basis , it may In relation to availability, storage supports grid reliability and resilience in response to natural disasters and other disruptions that require backup power . To expaFor both recognition and procedural justice tenets, the assessment is on the processes of public participation: due process, representation, citizen engagement, and community consultation .Recognition equity states that individuals must be fairly represented, and it reflects upon who exactly to focus on when thinking of energy victims , 20. ThiProcedural equity deals with the fairness of the decision-making process. Energy decision-making processes are highly complex. While there is a strong principle of third-party participation in the energy system, as captured for example in the Public Utility Regulatory Policies Act (PURPA) and the Open Access Transmission Tariff (OATT), or in independent market environments, participation still requires significant legal, financial, and engineering sophistication. To achieve procedural equity, decision-making requires full participation, adequate information, complete expression of opinion, and the impartiality of decision-makers.The business model of aggregation of distributed energy resources is based on the integration of renewables onto the grid, in part spurred by storage systems’ potential to serve larger grid functions . Energy Energy storage planning and siting could be executed in a way that advances recognition and procedural energy equity. Continued progress in battery storage research and development has increased the efficiency and safety of storage systems making them fairly attractive . ThroughAs distributed energy resources (DER) transform the energy independence of communities, storage is a key enabler in the business model. Smaller grids with renewable resource-driven technologies are subject to more volatility without the ability to mitigate across a larger grid. Typically, this is managed with a dispatchable scalable resource such as a diesel generator. Storage is essential to maintaining non-emitting small grids, protection from fuel price spikes and supply chain shortages, while supporting independent renewable resource-driven systems . These aStorage business models that advance community wealth also have implications for recognition and procedural equity, consider implementation of community energy storage systems (CES) . CES is Currently, there are two pathways for CES development—local and virtual . A localAdvancing restorative equity aims to repair the harm inflicted by energy systems ••, 25. AApplying restorative equity works to reverse and repair the harms done in such scenarios. Storage is facilitating the clean energy transition by allowing more renewable energy to come onto the grid while maintaining reliable operation . While iIn the context of energy systems, equity has two dimensions. The first relates to the lack of access to energy technologies. Low-income people and other minorities have been left out from accessing these resources due to systemic socio-economic barriers. The second is the inequitable distribution of the benefits and burdens energy systems create. These equity dimensions highlight the need to integrate justice concepts in the context of energy systems. This paper offered an equity framework to assess energy systems through the lens of the energy justice concept. It made the connection between energy system inequities and the capabilities offered by energy storage to enhance equitable outcomes.In the changing energy landscape, energy storage is playing a critical role in maintaining the electric grid stability and reliability, and in expanding electric vehicles (EV) market penetration. The advancement in energy storage and the growth in the EV market will shape the future of the electric grid infrastructure, the transportation sector, and the broader regulatory and policy agenda in creating equitable synergies. Beyond the techno-economic capabilities of energy storage in grid system resilience, it can provide effective means to enhance equity in the power system. These benefits could be through improving public health, providing backup power during outages, decreasing the cost of energy and saving money for customers, and reducing environmental impact. To enhance the equity potential of energy storage, further research is needed in the techno-economic, and regulatory and policy dimensions. Research design should integrate energy justice principles to align storage penetration with desired equity outcomes.


The importance of post-translational modifications (PTMs) has been realized since the 1950s in eukaryotic cells. Since the turn of the century, we now realize that PTMs are ubiquitous in bacteria, and we must now turn our attention understanding the underlying function and purpose of these modifications. Modification of the side chains of critical amino acids in proteins may have important functional consequences, such as altering enzymatic activity, inhibiting DNA-binding activity, or altering protein conformation. Bacterial PTMs can be challenging to study, due to their relatively low stoichiometry, and inherently unstable nature. With the advancement of mass spectrometry-based proteomics workflows, detailed large-scale characterization of PTMs became possible. Today, there are thousands of identified PTMs, including phosphorylation, acetylation, and succinylation, distributed among hundreds of proteins in over 40 different bacterial species. However, the biological significance of the majority of such modifications still remains unknown. Moreover, the mechanisms of control of these processes and the enzymes involved are not completely understood.Acinetobacter baumannii . The secreted phosphorylated proteins were characterized during two modes of growth, planktonic and biofilm. Interestingly, important virulent factors, such as those involved in adhesion, secretion and drug resistance were modified. The impact of a phosphorylated serine on the protein Hcp was also demonstrated by site-directed mutagenesis on the formation of a fully active type VI secretion system. Our next article explores the widely conserved, NAD+-dependent, lysine deacetylases, called sirtuins . The sirtuins have been well-characterized in eukaryotic systems, but their function and substrates in bacteria are not completely understood. This review provides an in-depth review of bacterial sirtuins in their physiology. An extensive phylogenetic study was performed that explores evolutionary relationships between sirtuins of different bacterial species and homologs. The next article looks at the process of acetylation/acylation from a mechanistic and structural biology perspective (Lammers). The current knowledge about the mechanisms of enzymatic regulation of lysine acetylation is discussed, including the known lysine acetyltransferases and classical Zn2+-dependent deacetylases. In addition, non-enzymatic acetylation, an important acetylation mechanism in bacteria, recent technological advances in the field and the physiological consequences of acetylation of well-characterized examples are discussed. The next article in the collection further explores the functional significance of the lysine acetylation of the histone-like protein HBsu in Bacillus subtilis . Previously, it was found that HBsu contains seven acetylation sites, and that acetylation of key residues is required for normal chromosomal compaction. In this work, it was demonstrated that acetylation of HBsu also regulates the process of sporulation, and furthermore, influences the environmental resistance properties of mature spores. In this collection, Ma et al. review the PTMs that have been identified in oral bacteria, and what is known about their function. The oral bacteria live in the complex and constantly changing environment of the oral cavity. This review focuses on various modifications, including acetylation, phosphorylation, glycosylation, citrullination, succinylation, and glutathionylation that were identified in oral bacteria. The corresponding modifying enzymes and the potential physiological role of each PTM are discussed. The penultimate article focuses on the lipoprotein post-translational modifications . Lipoproteins are tethered to membranes by a lipid anchor and are abundant in bacteria. They often function as enzyme inhibitors, transporters, and importantly, virulence factors. The latest developments in understanding lipoproteins and their synthesis are described. A discussion is included about how this new information is being used for the development of vaccines and antimicrobial therapeutics. Finally, the collection concludes with an original research article, describing a structural analysis of acetylation sites among orthologs across multiple bacterial species and organisms . The structures of five substrates of the lysine acetyltransferase YiaC were examined in-depth. Comparison of hundreds of structures in the Protein Data Bank (PDB) ultimately revealed inconsistencies in conclusions about lysine residue conservation in homologs based on primary linear sequence alone compared to the 3D structure. This highlights the need to consider where acetylation sites fall in three-dimensional space, when considering evolutionary conservation.This special topic issue focuses on newly identified PTMs, characterizing novel physiological functions of PTMs, and characterizing the enzymes involved. The first article in the collection characterizes the serine, threonine, tyrosine (STY) phosphosecretome in the opportunistic pathogen This special issue thus highlights original research and review articles on the topic of post-translational modifications in bacteria. They clearly illustrate the importance  of characterizing both the modified proteins and the enzymes involved in the addition/removal of PTMs, and of determining the impact of the modified residues on bacterial physiology . All of these actors may be ultimately represent targets of interest to develop novel therapeutics to fight bacteria.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.


The COVID-19 pandemic is a global challenge, demanding researchers address different approaches in relation to prevention, diagnostics and therapeutics. Amongst the many tactics of tackling these therapeutic challenges, small extracellular vesicles (sEVs) or exosomes are emerging as a new frontier in the field of ameliorating viral infections. Exosomes are part of extracellular vesicles (EVs)—spherical biological structures with a lipid bilayer of a diameter of up to 5000 nm, which are released into the intercellular space by most types of eukaryotic cells, both in physiological and pathological states. EVs share structural similarities to viruses, such as small size, common mechanisms of biogenesis and mechanisms for cell entry. The role of EVs in promoting the viral spread by evading the immune response of the host, which is exhibited by retroviruses, indicates the potential for further investigation and possible manipulation of these processes when tackling the spread and treatment of COVID-19. The following paper introduces the topic of the use of exosomes in the treatment of viral infections, and presents the future prospects for the use of these EVs. Viral pandemics are not a new phenomenon, as even the first steps towards transport and global development contributed to their formation and spread . A pandeExosomes were first described in 1981, as fragments of the membrane isolated from the biofluid . The disAs scientists have yet to come to a consensus on specific markers that would clearly distinguish, for example, exosomes from ectosomes, the authors of MISEV2018 strongly encourage the use of the general term “EVs” to describe all extracellular vesicles . As we rThe first two of the above category proposals were also successfully implemented in the article by Joanna Kowal, one of the participants in a leading exosome research team led by Clothilde Théry .Although recent guidelines suggest the use of the term EVs to denote a heterogeneous extracellular vesicle population, MISEV do not prohibit use of different terms to distinguish individual vesicles . It is aExtracellular vesicles are spherical biological structures with a lipid bilayer of a diameter of up to 5000 nm, which are released into the intercellular space by most types of eukaryotic cells, both in physiological and pathological states ,37,38,39Although EVs are similar to each other, they most often differ in their place of origin. By studying exosomes, researchers found their most intense production mainly in dendritic cells, mast cells, B lymphocytes, adipocytes, neurons, and epithelial and endothelial cells . An inteIt is important to consider the lifecycle of an exosome to truly understand the role of exosomes in viral infection. The full process of creating exosomes via classic ESCRT path is described in There is also another way of exosome biogenesis in which ESCRT plays a role–the interaction of ESCRT-III/ALIX with syndecan (the transmembrane proteoglycan receptor) and syntenin, as the binding component ,50. SyndTetraspanin-Mediated Biogenesis (TMB) and Lipid-Mediated Biogenesis (LMB), belonging to the ESCRT-independent pathways are additional pathways for consideration . The tetRAB27A may result in a reduction in the secretion of exosomes to the extracellular space [RAB27A and RAB27B silenced cells produce half as many exosomes as unmodified cells [RAB27A increases the size of the MVE, while silencing RAB27B redistributes the MVE towards the perinuclear region, instead of towards the plasma membrane [The transport of MVB to the cell membrane is mainly driven by the Rab family of small GTPase proteins. Rab family proteins also take part in the formation of vesicles inside the MVB, controlling their mobility by interacting with the cytoskeleton of the cell, and docking the vesicles to their destinations near the cell membrane ending with the release of vesicles into the intercellular matrix ,59. For ar space . Rab27A ar space . Accordiar space . Therefoed cells . Additiomembrane .Once the MVBs are near the cell surface, their membranes fuse with each other. Vesicles located inside the MVB are transported outside the cell, thus becoming exosomes . LocatedHowever, the main feature of exosomes is their role as carrier molecules protected by a lipid bilayer. The role of exosomes in tumor progression has been previously described in the literature, for example through the exosome mediated exchange of RNA between glioblastoma and endothelial cells , oncogenThe mechanisms of exosome uptake and delivery of their content to the cytosol of acceptor cells  have notThe second step in exosome capture is selection of the point of entry into the acceptor cell. It is not entirely clear whether it is due to a non-specific process such as macropinocytosis or phagocytosis, or through a specific receptor-dependent pathway . It has The third and final step in exosome internalization is delivering the contents to the receiving (acceptor) cell. In many studies, the final result of internalization is not deliberated or assessed by researchers, which makes it difficult to draw conclusions about the functional consequences for cargo transport via an exosome or other EV. The plasma membrane has been proposed as a target membrane for content delivery through membrane fusion with an exosome , which iOver the last century, modern medicine has made significant advances in the prevention, diagnosis, and treatment of disease. However, inhibition of viral pathogens remains a significant challenge . ImplemeAmongst the many approaches in tackling these challenges, extracellular vesicles (EVs) are emerging as the new frontier in prevention of viral infections. EVs are released into the intercellular space by most types of eukaryotic cells, both in physiological and pathological states, and thus must be taken into consideration while studying viral infections. Furthermore, EVs are involved in cell-to-cell communication by means of horizontal transfer of molecules at short and long distances .EVs share structural similarities to viruses, such as: small size, common mechanisms of biogenesis and mechanisms for cell entry. Using the endocytic pathway, viruses enter the host cell and exit the cell by “budding” through the cell membrane . The posFurthermore, as exosomes and extracellular vesicles are potential mediators of viral infection, further studies are needed to explore their potential role in reinfection and reactivation. Some authors suggested the role of released SARS-CoV-2-loaded exosomes and other extracellular vesicles as potential mechanisms for the relapse of the COVID-19 infection. Extracellular vesicles containing Covid-19 may be a possible mechanism for the reappearance of the viral RNA in the recovered COVID-19 patients 7–14 days post discharge, suggesting that viral material was hidden within such exosomes or extracellular vesicles during this “silence” time period and then re-spread  Figure .While researchers are racing to identify and map the details of the molecular infection profile of SARS-CoV-2 through proteomics at different times after infection , other gThe action of EVs is mostly associated with their content, dependent on the state of homeostasis, as well as the cells of origin, which can include molecules such as nucleic acids or proteins . Hence, After the outbreak of Sars-associated (SARS-CoV) in 2002, Kaute et al. 2007  exploredWhile most of the candidate and approved vaccines for SARS-CoV-2 are based on immunization with the viral spike protein delivered on viral vectors, encoded by injected mRNAs, or as purified protein, emerging publications propose exosomes to deliver mRNAs that encode antigens from multiple SARS-CoV-2 structural proteins . ExosomeIntranasal administration of vaccines would resemble the actual CoV-2 infection and could induce systemic immunity, and at the same time promote immunity of the mucosal barriers .Furthermore, exploring the possibility of the regulation of systemic inflammatory response against the virus with the initial phases of the mucosal reaction at its entry point could improve the longevity of the acquired immunity.The constant challenge in intranasal vaccination is to ensure safety while securing immunogenicity and subsequently sterilizing immunity. Intranasal administration of vaccines requires efficient adjuvants. Exosomes isolated from proinflammatory immune cells could be used to reinforce the immune response of a vaccine .Exosomes can be efficient vehicles for the delivery of functional mRNAs for use as therapeutics. Furthermore, the implementation of mesenchymal stem cells (MSCs) and their exosomes (MSC-Exo)  may be oMany types of nanoparticle structures have found their application in medicine, becoming a part of drug delivery systems. While liposomes are now at the forefront of virus and vaccine issues, cells are believed to offer other structures that can outperform traditional systems ,116. MeaDespite the ongoing research on exosomes in the context of viral infections, these structures still surprise with the range of their possible application. However, scientists should be aware that few biological tools are flawless, and although there have been suggested positive effects of EVs in the fight against viruses, exosomes can also promote inflammation . Further


To investigate the effects of dental/skeletal malocclusion and orthodontic treatment on four main objective parameters of chewing and jaw function  in healthy children.Systematic searches were conducted in MEDLINE (OVID), Embase, and the Web of Science Core Collection. Studies that examined the four parameters in healthy children with malocclusions were included. The quality of studies and overall evidence were assessed using the Joanna Briggs Institute and GRADE tools, respectively.The searches identified 8192 studies; 57 were finally included. The quality of included studies was high in nine studies, moderate in twenty-three studies, and low in twenty-five studies. During the primary dentition, children with malocclusions showed similar MOBF and lower chewing efficiency compared to control subjects. During mixed/permanent dentition, children with malocclusion showed lower MOBF and EMG activity and chewing efficiency compared to control subjects. The jaw kinematics of children with unilateral posterior crossbite showed a larger jaw opening angle and a higher frequency of reverse chewing cycles compared to crossbite-free children. There was a low to moderate level of evidence on the effects of orthodontic treatment in restoring normal jaw function.Based on the limitations of the studies included, it is not entirely possible to either support or deny the influence of dental/skeletal malocclusion traits on MOBF, EMG, jaw kinematics, and masticatory performance in healthy children. Furthermore, well-designed longitudinal studies may be needed to determine whether orthodontic treatments can improve chewing function in general.Comprehensive orthodontic treatment, which includes evaluation and restoration of function, may or may not mitigate the effects of malocclusion and restore normal chewing function.The online version contains supplementary material available at 10.1007/s00784-021-04356-y. Mastication is a complex sensory-motor interaction between the central nervous system and the peripheral masticatory apparatus. The semi-automatic, rhythmic act of mastication is initiated by the central nervous system and fine-tuned by inputs from receptors embedded in the orofacial area . The proIn children, the sensorimotor systems must adapt to substantial morphological changes during growth and development. The orofacial area is particularly challenged by the growth and development of the jaws and the transition from primary to permanent dentition . StudiesOrthodontic correction is often the preferred treatment method for correcting malocclusions. In more severe cases where orthodontic treatment appears inadequate, orthognathic surgery is recommended. Most orthodontic examinations involve a physical/radiographic assessment of deformities without evaluation of function. Orthodontic treatment is generally aimed at improving dental occlusion and enhancing esthetics, with little attention to restoring or optimizing chewing function. A number of studies have been published describing the effects of mandibular muscle activity in individuals with different categories of malocclusion (for a review: ). AlthouIn a previous systematic review, we examined the development of common objective indicators of chewing and jaw function  in healthy children without malocclusion . Buildinhttps://osf.io/7k3ue/) and was conducted according to the recent updates of the PRISMA-P guidelines [The protocol of the current systematic review was pre-registered in the Open Science Framework repository (idelines .Systematic searches were conducted in MEDLINE (Ovid), Embase, and Web of Science Core Collection databases from inception until October 29, 2021. The search strategy  screened the titles/abstracts of the study list. Clinical studies that investigated the objective parameters of jaw motor function and mastication in children with malocclusion, with or without cross-comparison to the malocclusion-free group of children and/or adults, were included. However, studies on children with other orofacial anomalies or in a language other than English were excluded. All reviews (systematic or narrative), study protocols, letters to editor, opinion articles, commentaries, and case reports were also excluded. Based on the inclusion/exclusion criteria, studies were categorized as “included,” “excluded,” or “undecided” using a predefined scheme. Indecision about the inclusion of a study was resolved by joint discussion and/or consultation with a third author (AK), if necessary. The full texts of all included studies were obtained and carefully read by the two independent authors. The studies that met the inclusion/exclusion criteria were finally included in this systematic review. A clear reason was provided for the exclusion of a study, and disagreements about the inclusion/exclusion of a study were again resolved by joint discussion and/or consultation with a third author (if necessary).The quality of evidence and risk of bias of the included studies were assessed using the Joanna Briggs Institute Critical Appraisal Tool. The purpose of this appraisal is to assess the methodological quality of individual studies and to determine the extent to which a particular study has addressed the possibility of bias in its design, conduct, and analysis. Two separate instruments related to methodological design  were used . The insThe database search resulted in 8192 studies, with five studies identified by manual search. After the removal of duplicates and screening of the titles/abstracts of the search results, a list of 150 potentially eligible studies remained for inclusion. Full-text review of the potentially eligible studies resulted in a final list of 57 included studies  with class II malocclusion, compared to adolescent girls with normal occlusion, had reduced chewing efficiency . SimilarRecently, it has been suggested that objective indicators of masticatory function in children aged 10 to 14 years show a transition to an “adult type” of chewing behavior . TherefoNormal jaw function depends on a harmonious relationship between the different components of the masticatory system. This harmonious relationship may be perturbed/disrupted in children with malocclusion, which may affect the normal development and function of the jaw . BesidesBite force is an important indicator of the functional state of the masticatory system . The resOrofacial deformities and malocclusions are thought to have varying degrees of impact on esthetics and masticatory function , 88, 89.As mentioned earlier, studies have reported that posterior malocclusions may have a greater impact on normal jaw function than anterior malocclusions. Since the posterior teeth are responsible for crushing, breaking down, and grinding food, a posterior malocclusion such as UPXB is more likely to affect oral functions, especially chewing , 96. AltAccording to longitudinal studies, a number of malocclusions (depending on their severity) may change during the period between the primary and permanent dentition , 98. In In the present study, the quality of evidence on the influence of orthodontic treatment on MOBF, jaw kinematics, EMG activity of jaw muscles, and chewing efficiency/performance in children with malocclusion was assessed using GRADE. The quality of evidence for all parameters was rated as “moderate” to “low.” The lower GRADE scores for quality of evidence were mainly due to the lack of well-controlled studies and studies that were unable to identify confounding factors. The lack of measures to deal with confounding factors and the heterogeneity of study samples, subgroups, and exposures also influenced the quality of evidence score. Indirectness due to substantial differences between the population, intervention, or outcomes measured in the relevant studies also influenced the outcome of quality of evidence. Therefore, orthodontic interventions have a greater impact on patient quality of life in addition to restoring esthetics and anatomy, but more robust longitudinal studies are needed to determine whether they improve masticatory function.The causes of dental malocclusion are, of course, multifactorial, but one of the mechanisms responsible for impaired chewing function in patients requiring orthodontic treatment may be due to impaired sensorimotor regulation associated with chewing. Therefore, it may be important for clinicians to perform a functional assessment in children in whom orthodontic treatment is indicated and identify specific impairments in chewing function. Assessment of oral function, such as bite force or chewing efficiency/performance, may also help to evaluate treatment success after orthodontic interventions. Comprehensive orthodontic treatment, including evaluations and restoration of function, can mitigate the effects of malocclusion and restore normal chewing function.It is recommended that the results of this review be interpreted with caution due to the quality assessment outcomes and the methodological heterogeneity of the studies. Specifically, twenty-six studies included in the current systematic review were classified as low quality, which may call into question the accuracy/validity of the findings. In addition, with the exception of two studies , 34, theAccording to the limitations of the studies included, it is not possible to confirm or deny the existence of an association between dental/skeletal malocclusion traits and MOBF, EMG, jaw kinematics, and masticatory performance in healthy children. The results also highlight the role of orthodontic treatment in the restoration of normal jaw function in affected children. However, the absence of well-controlled and well-designed studies, nevertheless, makes it impossible to conclude whether comprehensive orthodontic treatment, which includes evaluation and restoration of function, may/may not mitigate the effects of malocclusion, and restore normal jaw motor and chewing function.Supplementary file1 (PDF 46 KB)Supplementary file2 (DOCX 30 KB)Supplementary file3 (DOC 55 KB)Supplementary file4 (DOC 56 KB)Supplementary file5 (DOC 54 KB)Supplementary file6 (DOC 54 KB)Supplementary file7 (DOCX 32 KB)Below is the link to the electronic supplementary material.


Recently, the microbiota-gut-brain axis (MGBA) has emerged as a target for therapeutic innovation. Impairment of dynamic relationships within the MGBA promotes the pathological features of metabolic diseases. However, experimental data on the MGBA has limited clinical application. This review summarizes recent studies and proposes that exploring the interaction among peripheral organs and the MGBA could verify the dominant role of the latter in the onset of metabolic diseases and promote the clinical application of research outcomes. We first emphasize the molecular basis of metabolic diseases caused by MGBA disorders, which manifests as bidirectional relationship. We also summarize related therapeutic strategies, along with limitations in their clinical application. Adipose tissue (AT) is dynamic during metabolic activities and might interact with components in the MGBA. Therefore, it is interesting to explore the interplay among the MGBA and different kinds of AT, including thermogenic adipose tissue and white adipose tissue (WAT). In addition, we also evaluate the functional specificity of adipose tissue derived mesenchymal stem cells (ADSCs) and the beige adipose tissue. Understanding the heterogeneity and molecular basis of the interaction between different kinds of AT and the MGBA could accelerate innovation in the diagnosis and therapy of metabolic diseases. The microbiota-gut-brain axis (MGBA) has consistently attracted attention because of its potential to provide innovative therapeutic strategies for metabolic and neurological diseases, such as obesity, type 2 diabetes mellitus (T2DM), depression, and Parkinson's disease Adipose tissue (AT) performs essential functions in energy storage and expenditure, as well as metabolic regulation Escherichia coli13 bacteria in the human colon The discovery of bidirectional interactions within the MGBA can be traced back to last century. Since the 1980s, it has been reported that intestinal peptide hormones, such as peptide YY (PYY) and cholecystokinin (CCK), constitute the foundation of the gut-brain interaction As one of the components that first encounter nutrients, the intestinal microbiota not only participates in digestion and absorption, but also acts as an observer of metabolic information The metabolites released by the intestinal microbiota could influence the physiological feature of orexigenic or anorexigenic peptides, including gastrointestinal tract-derived ghrelin, glucagon like peptide-1 (GLP-1), PYY, and CCK, mainly by controlling the quantity of secretion and adjusting the chemical state of cytokine receptorsLactobacillus brevisNotably, the intestinal microbiota can interact with neurotransmitters in the intestinal cavity. These neurotransmitters are reported to be dynamic in promoting gut-brain interaction wexlerae reveal the mechanism of metabolic disorders caused by excessive intake of red wine and soda Enterobacteriaceae family In addition, the bile acid signature determined by intestinal microbiota also contributes to the homeostasis of peripheral metabolic status. During food intake, conjugated bile acids from the liver enter the intestine through the bile duct, assisting the digestion of lipid food, and are converted into secondary bile acids, including deoxycholic acid and lithocholic acid, through the modulation of microbiota. Subsequently, these secondary bile acids are effectively reabsorbed (> 95%) into the liver in the ileum and colon through activating the farnesoid X receptor (FXR) 4 receptor In metabolic diseases, the disorder of endocrine signals not only disturbs the peripheral metabolic state, but also promotes the transmission of neural signals through binding the surface receptors of enteric neuron or vagal afferent neuron (VAN). For instance, the neuroanatomy of adult enteric nervous system (ENS) is determined by the release of gut 5-HT and the activation of 5-HTProteobacteria , monitors the sugar content in food and circulation simultaneously, and adjust its compartmentalization in response to glucose fluctuation lactobacilli , induces endocrine signals, such as nitric oxide, at the ENS through the same pathways as those in obesity to regulate glucose uptake in the liver, pancreas, and adipose tissue by adjusting the ANS output Concerning diabetes, on the one hand, the decline of butyrate biosynthesis and the deterioration of oxidative stress originating from the damage of intestinal environment homeostasis accounts for the proinflammatory state characterizing diabetes The brain to gut pathways induced by brain-derived signals also contribute to dynamic functions of the MGBA. Early brain imaging studies showed that CNS signal variation, deriving from human emotional and cognitive changes, can be transmitted through autonomic nerves to regulate food intake and gastrointestinal contractile function Bacteroidetes/Firmicutes ratio in the gut In addition, compared with the control group, GF mice transplanted with an 'obese microbiota' displayed an obvious increase in whole body fat, which could be attributed to the abnormal Bifidobacterium, Lactobacillus, and Faecalibacterium prausnitzii, which suggests a good application prospect in the treatment of metabolic diseases The molecular mechanisms of the gut to brain pathways within the MGBA provide scope for improvement of therapeutic strategies against metabolic diseases. First, studies based directly on the intestinal microbiota have illustrated that bacterial diversity, along with its metabolites, are closely related to diet and exercise Clostridioides difficile infection Secondly, compared with the diet and exercise, fecal microbiota transplantation (FMT), has become a hot research topic in recent years, the effectiveness of which in the treatment of metabolic diseases, including obesity and irritable bowel diseases, such as ulcerative colitis and IBS, has been proven in some randomized controlled trials in vivoEmotional factors contribute to adverse symptom severity and health-related quality of life for patients with metabolic diseases; therefore, the utilization of antidepressants and psychological therapies has become more popular in recent years In summary, functional disorders of the MGBA, which are reflected in both peripheral and central aspects, are deeply involved in the development of metabolic diseases. Although our increasing knowledge regarding signal pathways provides many potential approaches for the treatment of metabolic diseases, analysis of the above data shows that there is still a long way to go before scientific achievements, including FMT and neuroengineering products, achieve clinical popularity. In addition to safety limitations, the lack of recognition of the crosstalk among the MGBA and other organs should be considered as well, because the pathogenesis of metabolic diseases often involves multidirectional interactions among various peripheral metabolic organs Adipose tissue acts as an essential organ in regulating energy and glucose homeostasis, which provides evidence for the subtle connection with metabolic diseases, and this metabolic regulating function has been proven also dynamic in humans Thermogenic adipose tissue, BAT and beige adipose tissue, is the core organ of non-shivering thermogenesis, the heating microenvironment homeostasis of which protects the body against cold and other extreme environments According to the nutrient status or dietary preference, the neurochemical phenotype of the intestinal VAN changes when combined with different kinds of intestinal peptide hormones, submitting orexigenic or anorexigenic signals to the CNS, the feedback of which, in turn, regulates gastrointestinal function In addition, produced by ileal enterocytes, fibroblast growth factor 19 (FGF19) and its mouse orthologue FGF15, are favored in the treatment of metabolic diseases. FGF19/15 are satiety hormones, and are negatively correlated with BMI and fat mass, while positively correlated with the expression of UCP1, which is the marker gene in BAT and beige adipose tissue In 2018, an elegant report revealed that intestinal hormones, especially secretin, released by diet stimulation, promoted thermogenesis in BAT, which could activate transient receptor potential vanilloid 1 (TRPV1) expressed in proopiomelanocortin (POMC) neurons and then promote satiation Adaptive thermogenesis and the promotion of energy expenditure are the main functions of BAT and the secretory profile of BAT has been highlighted in recent years In addition to proteins, BAT also secretes miRNAs, which exist in the exosomes of brown adipocytes and are secreted by BAT under certain environmental stimulations Originating from the browning of WAT, beige adipose tissue expresses a low basal level of UCP1, but is somewhat sensitive to cAMP signaling, which is associated with thermogenesis WAT is one of the largest metabolic organs in the body, and is involved in physiological processes such as energy storage and metabolism The interaction between WAT and the MGBA has a bidirectional form. First, the MGBA maintains the lipid storage capacity of WAT. On the one hand, the intestinal microbiota might affect lipid metabolism, which is involved in adjusting the fat mass and regulating lipid aerobic oxidation. Transplanting a normal microbiota from the distal intestine of conventionally raised mice into GF mice contributed to rapid hepatic lipogenesis and insulin resistance, which is caused by the inhibition of fasting-induced adipocyte factor (Fiaf) in GF mice after bacterial transplantation Entamoeba histolytica significantly because of the presence of the R233 residue in the cytokine receptor homology 1 region located in the extracellular loop of the lepR, which inhibited the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3)/protein kinase B (Akt) pathway and activated caspase-3 to induce epithelial cell apoptosis Lactobacillus rhamnosus GG (LGG) can improve the composition of the intestinal microbiota and reverse leptin resistance after an HFD, which is closely related to the upregulation of hypothalamic cytokine signaling-3 after LGG treatment Bacillus adolescentis isolated from the elderly can increase the concentration of serum leptin and induce the expression of thermogenic and lipid metabolism-related genes in adipose tissue Panax notoginseng saponins can increase the abundance of Akkermansia muciniphila and Parabacteroides distasonis by activating leptin-AMP-activated protein kinase (AMPK)/signal transducer and activator of transcription 3 (STAT3) pathway to increase the browning potential of WAT Several endocrine factors derived from WAT flow into the bloodstream and reach distant organs ADIPOQ mRNA (encoding adiponectin) in inguinal WAT ADIPOQ and RETN (resistin) promoters, which could be attributed to the down-regulated expression of methylation-related genes, including DNMT1 (encoding DNA methyltransferase 1) and DNMT3a (encoding DNA methyltransferase 3a) Other factors secreted by WAT, including adiponectin and resistin, could interact with the MGBA the same way as leptin. Injection of testosterone cypionate or sesame oil vehicle into pregnant rats in late gestation altered the composition of the intestinal microbiota as well as promoted the biosynthesis and elongation of SCFAs. Notably, these rats also showed increased body weight, which was related to the up-regulation of Firmicutes/Bacteroidetes and the abundance of Ruminococcus lactaris, Dorea longicatena, and Lachnospiraceae family Growing evidence underpins that there exist abundant immune cells in WAT. Endocrine factors derived from these immune cells also promote the crosstalk between WAT and other organs. The increase of circulating pro-inflammatory factors, including IL-1β, IL-6 and tumor necrosis factor (TNF)-α, impairs the BBB permeability of aged rats and attenuates tolerance to ischemic brain injury, while the removal of visceral adipose tissue decreases these inflammatory factors and partially reverses relevant brain damage Interestingly, WAT-derived secretory factors also include miRNAs, for example, specific metabolites of intestinal microbiota, especially tryptophan metabolites, regulate the expression of miR-181 in white adipocytes to strictly control energy expenditure, obesity, WAT inflammation, and insulin sensitivity ADSCs mainly originate from WAT, and are capable to differentiating into various tissues derived from the mesoderm, including bone, cartilage, muscle, and adipose. Their differentiation function, along with their wide availability, have meant that ADSCs have been employed as a potential tool in the field of soft tissue regeneration and reconstruction In the gut, the therapeutic roles of ADSCs are associated with increasing the diversity of the intestinal microbiota and inhibiting the abundance of pathogenic bacteria, which could reduce the secondary damage caused by intestinal mucosa injury and metabolic disorders caused by sepsis and IBD Keap1 gene (encoding Kelch like ECH associated protein 1) alleviated obesity, diabetes, and liver steatosis Although modulating the components of the MGBA is emerging as a novel advantage of ADSCs, it remains difficult to verify the systematic influence of ADSCs on the whole MGBA, and there have been few studies associating ADSC-induced CNS signals with various related metabolic diseases. However, the BNDF-TrkB pathway and Nrf2 protein are not only related to inflammation in CNS, but also regulate the metabolic function of peripheral organs In recent years, the previously unknown function of the MGBA has been gradually uncovered, providing numerous efficient treatment targets and innovative therapeutic modes for various diseases. From a traditional perspective, the gut and brain act as two central regulatory systems, the interaction between which contribute to connection among various kinds of diseases and ensures more systematic awareness of the pathogenesis of each disease. However, there are two obvious deficiencies in recent research. First, although studies have gradually explored the therapeutic role of the MGBA in metabolic diseases, they attached too much attention to the relationship between the microorganisms' ecosystem and metabolic diseases. In fact, the intestinal microbiota is only a peripheral initiating factor, and its subsequent induction process within the MGBA manifests as a dynamic and holistic feature. Therefore, we first reviewed the gut to brain pathway initiated by the intestinal microbiota to thoroughly analyze the pathways concerning how the MGBA dynamically regulates the development of metabolic diseases from regional to holistic perspectives. Second, brain-derived signals, together with the MGBA, also promote the incidence of various metabolic diseases indirectly, especially obesity, mainly through the HPA axis or the ANS, which constitutes the brain to gut pathway of the MGBA. These two pathways form a bidirectional regulatory framework within the MGBA, determining the molecular basis of which will lead to a deeper understanding of the dynamic processes of metabolic diseases induced by the MGBA. Most metabolic diseases belong to the category of chronic diseases; therefore, future studies should focus on exploring the dynamic molecular changes within the MGBA during the progress of metabolic diseases to optimize therapeutic strategies at different stages of the disease.Generally, research achievements based on the MGBA have not been translated satisfactorily to clinical applications in metabolic diseases. Therefore, the latter part of this paper mainly explored the interaction between peripheral organs, such as different kinds of AT, and the MGBA, to enrich the theoretical basis of the MGBA in the treatment of metabolic diseases. There is heterogeneity in the crosstalk between different kinds of AT and the MGBA; therefore, the molecular basis of their differences should be determined. In particular, analysis of ADSCs showed that their interaction with the MGBA has promising implications for the innovation of therapeutic strategies concerning metabolic diseases. It is worth noting that the abundant nerve fibers and efficient endocrine function of AT provide anatomical and physiological foundations for its interplay with the MGBA, suggesting that this interaction involves the integration of neuroimmunology and endocrine metabolism. In conclusion, future research should continue to screen the key molecular targets or pathways for the treatment of metabolic diseases, and pay attention to the dynamics of the different stages of these diseases and the significance of multidisciplinary integration to study the development of metabolic diseases.


Glaucoma is a group of irreversible blinding eye diseases characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons. Currently, there is no effective method to fundamentally resolve the issue of RGC degeneration. Recent advances have revealed that visual function recovery could be achieved with stem cell-based therapy by replacing damaged RGCs with cell transplantation, providing nutritional factors for damaged RGCs, and supplying healthy mitochondria and other cellular components to exert neuroprotective effects and mediate transdifferentiation of autologous retinal stem cells to accomplish endogenous regeneration of RGC. This article reviews the recent research progress in the above-mentioned fields, including the breakthroughs in the fields of in vivo transdifferentiation of retinal endogenous stem cells and reversal of the RGC aging phenotype, and discusses the obstacles in the clinical translation of the stem cell therapy. Glaucoma is a heterogeneous group of chronic neurodegenerative disorders characterized by relatively selective, progressive damage to the retinal ganglion cells (RGCs) and their axons, which leads to axon loss and visual field alterations. The heterogeneity of the disease makes its treatment difficult ,2. It isThe pathologically elevated intraocular pressure (IOP) is the main but not the only risk factor for the progression of the glaucoma damage. However, treatments aimed at decreasing IOP are ineffective in many cases, which might be explained in a few ways. First, the values obtained through IOP measurement cannot reflect the real physiological state, which affects the setting of target IOP. It is important to keep in mind that IOP is not a static parameter but undergoes dynamic changes; thus, it is of great need to further develop measurement equipment that allows long-term, continuous monitoring of IOP . Second,The unlimited proliferation ability and multi-directional differentiation potential of stem cells have made cell replacement therapy a promising therapeutic option. The use of stem cell replacement therapy for corneal blindness, macular degeneration, and retinitis pigmentosa has become the hot spot of the relevant research, and globally, there are a number of ongoing clinical trials on the replacement of corneal cells and retinal pigment epithelial cells . At presAs the RGCs of adult mammals and humans lack the ability to self-regenerate and their self-repairment ability is inhibited by certain signals, the source cells for RGC replacement mainly come from the induced differentiation of retinal progenitor cells or stem cells. Due to the limited source of retinal progenitor cells, many studies have focused on the exploration of technology for the induced differentiation of stem cells into RGCs, and a series of breakthroughs have been made in the past decade.Recently, we described in detail the various differentiation induction systems currently used in RGC replacement research ,11. GeneIn the past decade, the advent of the 3D retinal organoid has greatly boosted the differentiation of various retinal neurons, including RGCs ,18,19,20However, a series of technical difficulties are yet to be overcome in order to obtain sufficient functional RGCs for in vivo transplantation. Firstly, purification and enrichment are essential to ensuring the proper functioning of cells and in avoiding tumor formation after transplantation. Currently, the main RGC purification methods include immumopanning, fluorescence-activated cell sorting (FACS), and magnetically activated cell sorting (MACS). By exploring the RGC-specific marker THY1, RGCs can be better isolated and purified from other cells ,23, and In addition, it is necessary to determine which developmental stage of RGC is more suitable for in vivo transplantation. In the study of photoreceptor cell replacement , it was Nonetheless, the broad-spectrum markers such as Brn3, Thy1, Pax6, Rbpms, and Isl1 that are widely used in current researches to identify RGCs derived from induced differentiation are not able to properly identify the development stage and subtypes of RGCs. The newly emerged single cell transcriptomics and single cell RNA-sequencing technology provided feasible solutions to the above two issues, as they can obtain the molecular characteristics of different RGC subgroups at different developmental stages from human tissues or 3D retinal organoids induced by hiPSC, providing relatively accurate identification markers for RGCs, then identifying the damage-resistant RGC subtypes ,33,34.The stem cell-based therapy mainly replaces the lost neurons through cell transplantation and thus makes up for the disadvantage that human RGCs cannot repair themselves. However, after highly undifferentiated stem cells are implanted into the retina, they rarely successfully differentiate into targeted retinal neurons. For example, after iPSC is directly transplanted into the vitreous cavity or subretinal space of the glaucoma animal model, these cells mainly differentiate into oligodendrocytes spontaneously . Thus, cGenerally, the main methods of transplantation are subretinal space transplantation and vitreous cavity transplantation. The transplanted cells can survive for several days to several months and integrate into the host retina, with the ganglion cell layer (GCL) as the primary location of integration . HoweverIn addition to replacement, intraocular transplantation of certain stem cells also has neuroprotective effects on surviving RGCs, mainly mesenchymal stem cells (MSCs), and these cells also possess the merit of easy-to-obtain autologous cells for therapeutic applications . In 2006MSCs can secrete a variety of cytokines, including brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), glial cell line-derived neurotrophic factor (GDNF), and basic fibroblast growth factor (BFGF), among which, BDNF has been proven to be an essential and effective protective factor for glaucoma optic nerve damage . ResearcIn recent years, exosomes secreted by MSCs have gradually gained attention in MSC-mediated neuroprotection. Exosomes are endocytic structures composed of proteins, lipids and mRNA, which can regulate the translation of proteins in target cells when delivered to target cells . IntraocTheoretically, activating the retinal endogenous regeneration and repair is the most direct treatment for RGC loss . The retExcept for the transdifferentiation of other types of cells in the retina, recent research work on reversing the senescence phenotype of RGC is also quite enlightening . The resIn 2016, Pearson et al.  discoverThere are still a few issues we need to take into consideration in the clinical translation of stem cell therapy for glaucoma.First of all, the most common concern in stem cell replacement therapy has always been potential ethical issues, as well as the immune response and tumorigenicity brought about by allogeneic transplantation. Though hESC has been studied at the early stage of the RGC replacement therapy, its clinical translation has been hindered by the above-mentioned issues. Since hiPSC can be derived autogenously, the ethical issues and immunological rejection are much easier to solve. However, if it is to be used in clinical practice, the cost of constructing autogenous iPSCs for each patient would be relatively high, and thus, it would not be easy to promote such a strategy clinically. In recent years, researchers have been focusing on building an iPSC cell bank for HLA matching, which can be used for transplantation directly after matching, so as to promote the industrialization of cell transplantation. Recently, Kyoto University used gene-editing technology to produce HLA-I-deficient iPS cells to further produce HLA-deficient platelets. In addition, they confirmed with cell experiments and animal model experiments that iPSC-derived platelets depleted of HLA would not be attacked by anti-HLA antibodies and NK cells. This study proves that iPSC-derived platelets depleted of HLA can be used as a “universal” broad-spectrum preparation for blood transfusion, further reducing the cost of scale preparation of multiple iPSC-derived platelets depleted of HLA subtypes , and alsSecondly, genetic factors also play a role in the development of glaucoma; thus, the constructed autologous iPS cells still carry the pathogenic genetic information. If RGC is the target of the pathogenic gene, RGC induced by iPS will still carry damaging factors, and thus, it may be necessary to consider in vitro gene repair prior to in vivo transplantation. Previously, our team constructed the iPSC of retinitis pigmentosa patients, and the iPSC was differentiated into 3D retinal organoids carrying the pathogenic gene information. Afterwards, we used CRISPR/Cas9 gene-editing technology to repair the mutation and found that the occurrence of retinal degeneration was successfully prevented in terms of the gene expression profile, protein level, and electrophysiological characteristics of the cell, validating the proof-of-concept of curing the cells before curing the disease . HoweverIn addition, the integration of the transplanted cells and the host retina needs to be further improved. After intravitreal or subretinal transplantation, the migration of the transplanted cells to the ganglion cell layer and its integration with the host retina are seriously affected by the physical barrier of the internal limiting membrane and pathological reactive gliosis. Researchers have discovered that aminoadipic acid (AAA), a drug that selectively inhibits glial cell activation, can significantly improve the migration and integration of cells after transplantation. In the study, the cells were injected into the vitreous cavity of normal mice and mice with glial response inhibition (AAA treatment), and it was found that more transplanted cells were integrated into the host retina of AAA-treated mice than in the control group . The appAnother challenge lies in the regeneration and effective projection of RGC axons. Strictly speaking, the functional replacement of RGC requires the completion of the synapse integration in the retina, and also, the RGC axons need to extend along the optic nerve to the target brain areas to form effective signal projection. Although axon regeneration in the central nervous system is hindered by many factors, a series of studies have confirmed that through the regulation of certain transcription factors and signaling pathways, RGC axon regeneration and projection to brain areas can be induced ,79,80,81Despite the above-mentioned challenges, there is no doubt that stem cell therapy has become the most promising therapeutic approach for the regeneration and protection of RGCs in advanced glaucoma. It could be expected that with the breakthrough in, and combined application of, biotechnologies such as single-cell omics, gene editing, tissue engineering and nanotechnology, the use of stem cells to protect, regenerate and replace damaged RGCs will play an essential role in helping glaucoma patients to regain their sight.


Spermatogenesis is one of the most important processes for the propagation of life; however, the testes’ ability to form sperm via this differentiation process is highly radiosensitive and easily impacted by exposure to environmental, occupational, or therapeutic radiation. Furthermore, the possibility that radiation effects on the gonads can be passed on from generation to generation should not be overlooked. This review focuses on the radiation-induced effects on spermatogenesis and the transgenerational effects. We also explore the potential of novel radiobiological approaches to improve male fertility preservation during radiotherapy.The genotoxicity of radiation on germ cells may be passed on to the next generation, thus its elucidation is not only a scientific issue but also an ethical, legal, and social issue in modern society. In this article, we briefly overview the effects of radiation on spermatogenesis and its associated genotoxicity, including the latest findings in the field of radiobiology. The potential role of transgenerational effects is still poorly understood, and further research in this area is desirable. Furthermore, from the perspective of oncofertility, we discuss the historical background and clinical importance of preserving male fertility during radiation treatment and the potential of microbeam radiotherapy. We hope that this review will contribute to stimulating further discussions and investigations for therapies for pediatric and adolescent/young adult patients. Spermatogenesis is an essential physiological process for living organisms, in terms of the inheritance of the genome. This long and dynamic differentiation process in the seminiferous tubules takes about 60–70 days in humans and about 30 days in mice, which results in the transformation of spermatogonial stem cells (SSCs) through spermatogonia, primary spermatocytes, secondary spermatocytes, and spermatids to spermatozoa, which then mature in the epididymis. During the spermatogenesis process, radiation-induced effects can cause reproductive toxicity . For higThe first recognition of the possibility of radiation-induced genotoxicity came in 1903 when Heinrich Albers-Schönberg demonstrated that X-rays could damage rabbits’ testes . HermannPublication 131, of the International Commission on Radiological Protection, the behaviour of stem cells in living tissues, particularly the competition and selection among them for the microenvironment (niche) necessary for stem cells to maintain their properties (stem cell competition), may be involved in radiation effects at the tissue level [In recent years, as the development of stem cell biology has deepened our understanding of the hierarchy of stem cell-centred tissues and the interactions between cells and their microenvironment, there has been a movement to re-evaluate the biological effects of radiation at the tissue level from the perspective of radiation biology . In factue level , and theTo clarify the radiation-induced effects on germ cells, it is also necessary to elucidate the potential role of transgenerational/genetic effects. However, these effects following paternal exposure are still controversial, probably because there appears to be a divergence between the results of animal experiments over the years and the results of epidemiological studies on humans, as discussed later in this review. In animal models, there have been several reports on the biological effects of radiation on the next generation; however, in the case of humans, previous studies, including epidemiological studies of people exposed to the atomic bombs in Hiroshima and Nagasaki, have shown no evidence of transgenerational effects of radiation. Genotoxicity in germ cells is not only a scientific issue but also an important ethical, legal, and social issue (ELSI). For example, it has become a major concern for victims of nuclear weapon fallout, victims of radiation accidents or nuclear disasters, and others who have suffered unexpected exposure to radiation. Therefore, from the perspectives of both radiobiology and epidemiology, future research on the transgenerational effects of radiation is required.This review outlines our current knowledge on spermatogenic impairment associated with radiation exposure and the potential effects on the next generation, as well as the importance of fertility preservation in cancer treatment, highlighting the latest findings in radiobiology. We hope that the summation of past findings in this field will lead to the development of future research strategies and improve understanding of radiation exposures on spermatogenesis and its impact on oncofertility.An experiment was conducted in the 1970s using prisoner volunteers who agreed to have their testicles irradiated to investigate the spermatogenetic effects of radiation in humans . ParticiFor many years, scientists have known that radiation can lead to a broad spectrum of DNA lesions, including damage to the nucleotide bases; DNA single and double-strand breaks (DSBs); cross-linking, and that exposure to radiation can seriously damage biological systems by triggering cell death or inducing mutations, which prompts radiation-induced carcinogenesis . The difROS cause several forms of sperm DNA damage, including chromosome deletion, chromatin cross-linking, base oxidation, and DNA strand breaks . ROS areSpermatogenic cells consist of several subpopulations, including SSCs and their differentiating progeny  , which hOne essential physiological mechanism that occurs in the testis is apoptosis, the process by which the number of germ cells in the seminiferous epithelium is limited . ClinicaSSCs are characterised by a lack of compacted heterochromatin. DNA damage detection and signalling are mediated in these cells by the absence of the transducer complex γ-H2AX/MDC1, and radiation-induced DSBs are most often repaired via DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-independent mechanisms . In respAt the onset of the first meiotic prophase, chromosomes receive Spo11-dependent DSBs that are repaired by homologous recombination (HR). This promotes crossing over and ensures homolog separation during the meiosis I division ,38. In cWhile candidate gene approaches have made some progress, they have, to date, been largely unsuccessful in identifying robust biomarkers of radiosensitivity at the individual level; this is due to the lack of an integrated understanding of the role of individual radiosensitivity in overall response . ClinicaMSH5 C85T (Pro29Ser) (rs2075789) is related to an increased risk of male sterility [p < 0.05), although the underlying mechanism has yet to be determined [The mismatch repair (MMR) pathway plays an important role in maintaining genomic integrity; meiotic recombination; and gametogenesis, and genetic polymorphisms in MMR genes have been determined to be involved in the aetiology of male infertility . MutS prterility  and raditerility . Radiothtermined . In additermined , the refInfertility is still an unfortunate adverse effect of most pelvic and systemic cancer therapies, including radiotherapy, as it impacts the quality of life of survivors during their pre-reproductive and reproductive years. For the improvement of clinical practice and health policy, such human genetic data is useful in deciding the future direction towards precision radiotherapy and radiation risk assessment in the world. The combination of population-based biobanking and genomics project has great potential to provide clinical information to help overcome or minimise radiotherapy-related adverse events including radiation-induced spermatogenic impairment. These findings may provide an important opportunity for the realisation of precision genetic medicine in the future ,49.Proceedings of the National Academy of Sciences was evidence for the first time of gene mutations (via the use of ionizing radiation), almost six months prior to Muller’s Science paper [In February 1927, Gager and Blakeslee reported the chromosome and gene mutations in the offspring of exposing flowers of Dature to Radium-derived radiation . Their pce paper . Since tce paper .Clethrionomys glareolus) around Chernobyl and butterflies (Zizeeria maha) around Fukushima following the nuclear accidents [Both epigenetic and genomic pathways have been suggested in explanation of the transmissible effects of environmental contaminants, including sperm DNA mutations, the suppression of germ-cell apoptosis, genomic instability, and imprinting errors ,53. Seveccidents ,61.Hypotheses concerning the transgenerational effects of paternal exposures to radiation remain controversial in their relationship to humans. A study by Jacqueline Fabia and Truong Dam Thuy in 1974 reported that paternal occupational exposure to chemical substances can affect the integrity of spermatogenesis and, potentially, lead to the transmission of carcinogenic defects in these workers’ children . In the Interventionary studies involving animals or humans, and other studies that require ethical approval, must list the authority that provided approval and the corresponding ethical approval code.The degree of adverse events in parallel organs  is thought to depend on the proportion of the volume of the subunit in the total organ that is irradiated with a dose that results in functional damage. Thus, dose-volume histogram analysis is commonly used as a countermeasure for adverse events associated with radiotherapy. However, as mentioned above, one defining characteristic of non-uniform exposures is that the observed dose–response relationships cannot be predicted from uniform exposures and then based on the standard radiobiological DNA damage and repair model . AlthougWhile recent improvements in treatment outcomes have resulted in fewer deaths among paediatric and AYA cancer patients, fertility preservation remains an increasingly important consideration in clinical oncology. Male patients, especially those with testicular or hematologic cancers or brain tumours, are more likely to present with infertility after being treated with some combination of chemotherapy and radiotherapy, thus affecting their quality of life. In addition, a previous study using marmoset models indicated radiation vulnerability in prepubertal testes . In lighOne typical fertility preservation therapy is sperm cryopreservation. In 2016, Moss et al. proposed that ejaculated semen is the most effective fertility-preserving therapy for male cancer patients in the AYA generation and should be collected before the start of cancer treatment . If ejacBrinster and Zimmermann, working in 1994, were the first to perform a male mouse germ cell transplant, thus demonstrating that the dynamics of SSCs via seminiferous tubules are important for maintaining spermatogenesis . They shCan a TSE following MRT occur during spermatogenesis? To answer this question, an ex vivo mouses testicular tissue culture , servingIn 2020, following up on their initial report , FukunagThe results of a recent study on ultra-high dose rate (FLASH) radiotherapy demonstrated the remarkable sparing of normal tissue at this high rate of irradiation (>40 Gy/s), thus suggesting that the dose rate is also important for effective TSE ,103,104.Although several previous studies have elucidated the effects of radiation on spermatogenesis and transgenerational effects, many unresolved issues remain. The preservation of fertility following radiotherapy is of importance for paediatric and AYA cancer patients. Radiobiological research using microbeams and other novel techniques is expected to make significant contributions to this field.


Antibiotic resistance (ABR) is a major global threat. Armed and protracted conflicts act as multipliers of infection and ABR, thus leading to increased healthcare and societal costs. We aimed to understand and describe the socioeconomic burden of ABR in conflict-affected settings and refugee hosting countries by conducting a systematic scoping review.A systematic search of PubMed, Medline (Ovid), Embase, Web of Science, SCOPUS and Open Grey databases was conducted to identify all relevant human studies published between January 1990 and August 2019. An updated search was also conducted in April 2020 using Medline/Ovid. Independent screenings of titles/abstracts followed by full texts were performed using pre-defined criteria. The Newcastle-Ottawa Scale was used to assess study quality. Data extraction and analysis were based on the PICOS framework and following the PRISMA-ScR guideline.n = 3), Iraq (n = 2), Jordan (n = 1), Palestine (n = 1) and Yemen (n = 1). Most of the studies did not have a primary aim to assess the socioeconomic impact of ABR and were small studies with limited statistical power that could not demonstrate significant associations. The included studies lacked sufficient information for the accurate evaluation of the cost incurred by antibiotic resistant infections in conflict-affected countries.The search yielded 8 studies (7 publications), most of which were single-country, mono-center and retrospective studies. The studies were conducted in Lebanon (This review highlights the scarcity of research on the socioeconomic burden of ABR on general populations in conflict-affected settings and on refugees and migrants in host countries, and lists recommendations for consideration in future studies. Further studies are needed to understand the cost of ABR in these settings to develop and implement adaptable policies.The online version contains supplementary material available at 10.1186/s13031-021-00357-6. Antibiotic resistance (ABR) and multi-drug resistance (MDR) are major global threats . They reAccording to a study conducted in Baghdad, disability due to conflict-related injuries affected more than half of injured civilians, most of which were caused by blasts and gunshot wounds . These tPreviously implemented interventions in regular settings, based on economic evaluations, have proven to be cost-effective in reducing the clinical and socioeconomic burden of ABR, such as the hospital wide intervention program implemented in Argentina to optimize antibiotic prescribing. Findings have shown that the program decreased resistance to certain antibiotics and contributed to substantial cost savings .The existing literature on the economic burden of ABR mostly consists of studies conducted in regular settings presenting inconsistent results. Several previous systematic reviews, of mostly retrospective and case-control studies, concluded that ABR is usually associated with significantly higher economic burden; however, none were specific to conflict settings –17. EconIn view of the inconsistent literature related to the socioeconomic burden of ABR in conflict settings, a systematic scoping review was conducted with the objective to answer the following research question: What is the socioeconomic burden of ABR in FCAS and in LMIC that are hosting refugee populations - hereinafter referred to as Refugee Hosting Countries (RHC) - compared to those with susceptible infections/colonization or control patients without infection/colonization? The aims of this review are: 1) to identify the available studies and the gaps in literature on the socioeconomic burden of ABR in conflict settings, 2) to assess the socioeconomic burden of ABR in FCAS and RHC, and 3) to raise awareness about the urgency of the problem and inform policy for the development and implementation of cost-effective interventions tackling ABR in these settings. To the best of our knowledge, this has not been done before and could provide valuable insights and guidance for future work in this area.The study design and analysis were conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines , Embase, Web of Science, SCOPUS and Open Grey databases was performed to identify relevant studies published between January 1990 and August 2019. An updated search was conducted on April the 6th, 2020 using Medline/Ovid. Additional searches were performed using Google Scholar and a manual search of citations of retrieved studies to identify articles that were missed by electronic search. Identified articles were imported into EndNote where duplicates were removed. A full description of the search terms and search strategy is provided in Appendix II  and therefore its financial burden; more importantly the studies were excluded as this microorganism is not specific to conflict-affected areas, subject of this review. Conference abstracts and posters were also excluded as 1) they are largely driven by their brevity and 2) their dependability is questionable.Several definitions of resistance patterns exist and differ between studies. Therefore, we summarized the details on diagnostic tests and definitions of resistance/multi-drug resistance in Table SIdentified records were initially screened for their relevance based on titles and abstracts. Articles were screened using the question: “Does this citation potentially describe the socioeconomic burden of antibiotic resistance in FCAS and RHC listed in the protocol?” Full texts of eligible articles were then retrieved and reviewed for inclusion. Articles were independently screened by two reviewers and uncertainty was resolved through discussion with a third author.We developed a standardized extraction form to record the characteristics of each study and major contributing factors to hospital and patients’ costs. Extraction information included first author, publication year, study period, study location, study design, study population, definitions of cases and controls, patient characteristics, hospital ward, source of infection, microorganisms studied, antibiotic drugs studied, ABR/MDR prevalence, length of stay, number of procedures performed, amputation, mortality, other outcomes, direct costs and indirect costs, as well as any other costs. The form was based on the PICOS framework and was tested on one of the articles to ensure that it covers all relevant information. Data extraction was conducted independently by two researchers and disagreements were resolved by a third reviewer. When relevant data was not published, authors were contacted for additional information. The summary of findings describes the study characteristics and reports the number of studies examining each of the variables considered. The findings describe the direction of the associations and the mean and percentage ranges, whenever possible.Study quality was evaluated independently by two authors using the Newcastle–Ottawa Scale (NOS), a tool to assess the quality of non-randomized studies , followed by Staphylococcus aureus (n = 4), and Escherichia coli (n = 3). Six studies reported the prevalence of MDR infections which ranged between 37.5 and 88%. However, none of the studies explicitly and comprehensively assessed the COI from resistant infections. Detailed characteristics of the studies included in this review are summarized in Table SThree studies were conducted in Lebanon (Beirut and Byblos) , 23, twoAcinetobacter infection was estimated to be around $1750 per day. The length of stay (LOS) was reported to increase by up to 2 weeks when patients were diagnosed with device-associated infections caused by the resistant organism, leading to an increase in hospitalization cost by $24,000 for every MDR Acinetobacter infection.Only one study estimated the average cost of hospitalization, direct cost, due to resistant infections . In thisTwo studies reported higher LOS for patients with resistant infections , 24; howAcinetobacter baumanii [Staphylococcus Aureus (MRSA) [Escherichia coli [Three studies investigated the suitability of the treatments provided to infected patients. The studies assessed the effectiveness of the medications prescribed to treat baumanii , Methicis (MRSA) , and Exthia coli . Inapprohia coli .One study evaluated the average number of procedures per patient , which cOne study assessed the risk of amputation in the different groups , which eThree studies reported higher mortality in patients with resistant infections , 26, 27.To the best of our knowledge, this is the first scoping review aiming at mapping and identifying the evidence regarding the socioeconomic burden of ABR/MDR infections compared to susceptible cases or those without infection or colonization in FCAS and RHCs. There were no studies identified with a primary aim to evaluate the COI of antibiotic resistance, was it from the perspective of the patient, payer or provider. This highlighted the gap in the available evidence on the socioeconomic burden of ABR in those settings. In fact, the identified studies rather assessed the clinical burden of certain infections. In these cases, the evaluation of bacterial resistance and its resulting outcomes and resource consumption were sub-analyses. Subsequently, the sample size for the populations of interest became very small and the results lacked statistical power. When an economic analysis was conducted, a hospital perspective was adopted without taking into account the indirect costs of ABR. LOS, a key driver of cost of infections in hospitals , was oneResults were not consistent between studies that investigated the difference in LOS of patients with resistant and comparator groups. In addition, the methodology used for this assessment also varied. Studies addressing LOS did not explicitly estimate attributable LOS, but rather the average LOS for the different groups. Studies also did not address the increased risk of death due to resistant infections, but rather reported the prevalence of mortality in the different groups. As for other settings, a study conducted in Australia reported that vancomycin resistance was associated with increased LOS and hospitalization costs . A systePrevious studies have led to the establishment of cost-effective policies that promote appropriate use of antimicrobials and prevent the spread of infections. Examples include the improvement of hand hygiene strategies which reduce LOS, number of deaths, and total costs , and theDespite the complexity of conflict-affected settings, it is essential that future studies ensure that definitions are clearly and accurately stated and that samples are representative to allow for standardization and better comparison and synthesis of the evidence to potentially generate reliable evidence and better understanding of conflict-affected settings;Data collection might not be a priority in these settings, therefore it needs to be consciously accounted for to generate relative risks or attributable risks of morbidity and mortality from ABR and excess LOS, ICU/hospital stay/cost, and antibiotic and other resource use/cost, whenever possible;It is important to consider the confounding effect of relevant covariates and to control for them. Building capacities of local researchers working in conflict-affected settings would improve the quality of studies conducted in these regions. The Structured Operational Research Training Initiative (SORT-IT), implemented and run by Médecins Sans Frontières (MSF) and the Union, and the Center for Research and Education in the Ecology of War (CREEW), run by the Global Health Institute at the American University of Beirut (AUB), are some examples of established programs aiming at equipping frontline health practitioners with the necessary skills to conduct research;It would be useful to adopt the conceptual framework for capacity strengthening of health research in conflict and adapting it to conduct economic evaluations in this setting, and advocating for translating research outcomes into services and policies .Researchers and health professionals play a role in providing evidence on the burden of ABR and in ensuring stakeholders take account of that evidence when developing policies . Based oWe conducted a comprehensive search of the literature in multiple databases using the PRISMA guidelines and we have identified the gaps and areas for future research. However, our study was subject to certain limitations. First, as we only included articles with English abstracts, potential language bias cannot be neglected. However, we did not limit our search to only English articles which could mean that the impact on the findings is negligible. Second, although the health burden of ABR has been previously associated with increased costs, most of the included studies in our review did not focus on estimating the excess cost attributed to resistant infections, preventing us from providing a clear estimate of the socioeconomic burden of ABR. Finally, the studies had a great deal of missing information, either due to the retrospective nature of most of the studies or to the emergency context in which the research studies were conducted, thus restricting the proper assessment of the socioeconomic burden of ABR in conflict-affected settings. Given the lack of relevant data, the results should be interpreted with caution.There is some evidence indicating that inappropriate antibiotic therapy leads to more resistant infections which is associated with prolonged hospital stay and higher mortality rates in conflict-affected regions. This review emphasizes the lack of studies addressing the socioeconomic burden of ABR in FCAS and RHC, partly due to lack of focused research on this topic and consequently data scarcity. It also highlights the need for well-designed longitudinal or large retrospective multicenter studies examining this relationship and accounting for all the variables that are intrinsic to the nature of conducting research in such challenging settings.Additional file 1: Table S1. Definitions: identification of organisms and susceptibility testing. Details on the microorganisms studied in each of the included studies, the diagnostic tests and the definitions of resistance/multi-drug resistance. Table S2. Characteristics of studies investigating the socioeconomic burden of ABR in conflict-affected countries. Characteristics of the studies included in the scoping review. The extracted data includes the first author, publication year, country of origin, center type and number of centers, total population, number of cases and comparison groups, population of interest if different from the total population, number of cases and comparison groups in the subsample, micro-organisms studies, infection and ABR/MDR prevalence, and key findings.Additional file 2: Appendix I. Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist. Appendix II. Medline/Ovid Search Strategy. Detailed search strategy for one of the databases used to conduct this scoping review. Appendix III. Categorization of countries according to the World Bank Data. “Fragile and conflict affected situations” and “Low & middle income”. Appendix IV. Quality assessment checklists. The Newcastle-Ottawa Scale to assess the quality of studies. Appendix IV. a. includes the checklist for all studies excluding cohort studies, and Appendix IV. b. includes the checklist for cohort studies.