Insights and implications of sexual dimorphism in osteoporosis

Osteoporosis,a metabolic bone disease characterized by low bone mineral density and deterioration of bone microarchitecture,has led to a high risk of fatal osteoporotic fractures worldwide.Accumulating evidence has revealed that sexual dimorphism is a notable feature of osteoporosis,with sex-specific differences in epidemiology and pathogenesis.Specifically,females are more susceptible than males to osteoporosis,while males are more prone to disability or death from the disease.To date,sex chromosome abnormalities and steroid hormones have been proven to contribute greatly to sexual dimorphism in osteoporosis by regulating the functions of bone cells.Understanding the sex-specific differences in osteoporosis and its related complications is essential for improving treatment strategies tailored to women and men.This literature review focuses on the mechanisms underlying sexual dimorphism in osteoporosis,mainly in a population of aging patients,chronic glucocorticoid administration,and diabetes.Moreover,we highlight the implications of sexual dimorphism for developing therapeutics and preventive strategies and screening approaches tailored to women and men.Additionally,the challenges in translating bench research to bedside treatments and future directions to overcome these obstacles will be discussed.

Oral squamous cell carcinomas:state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% oforal malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases werereported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ),and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oralmucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involvesgenetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeuticinterventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCCand OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors,thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC.Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitatecomprehension and provide several prospective outlooks for the fields.

Managing the immune microenvironment of osteosarcoma:the outlook for osteosarcoma treatment

Osteosarcoma,with poor survival after metastasis,is considered the most common primary bone cancer in adolescents.Notwithstanding the efforts of researchers,its five-year survival rate has only shown limited improvement,suggesting that existing therapeutic strategies are insufficient to meet clinical needs.Notably,immunotherapy has shown certain advantages over traditional tumor treatments in inhibiting metastasis.Therefore,managing the immune microenvironment in osteosarcoma can provide novel and valuable insight into the multifaceted mechanisms underlying the heterogeneity and progression of the disease.Additionally,given the advances in nanomedicine,there exist many advanced nanoplatforms for enhanced osteosarcoma immunotherapy with satisfactory physiochemical characteristics.Here,we review the classification,characteristics,and functions of the key components of the immune microenvironment in osteosarcoma.This review also emphasizes the application,progress,and prospects of osteosarcoma immunotherapy and discusses several nanomedicine-based options to enhance the efficiency of osteosarcoma treatment.Furthermore,we examine the disadvantages of standard treatments and present future perspectives for osteosarcoma immunotherapy.

Oxidative stress and diabetes:antioxidative strategies

Diabetes mellitus is one of the major public health problems worldwide.Considerable recent evidence suggests that the cellular reduction-oxidation(redox)imbalance leads to oxidative stress and subsequent occurrence and development of diabetes and related complications by regulating certain signaling pathways involved in p-cell dysfunction and insulin resistance.Reactive oxide species(ROS)can also directly oxidize certain proteins(defined as redox modification)involved in the diabetes process.There are a number of potential problems in the clinical application of antioxidant therapies including poor solubility,storage instability and nonselectivity of antioxidants.Novel antioxidant delivery systems may overcome pharmacokinetic and stability problem and improve the selectivity of scavenging ROS.We have therefore focused on the role of oxidative stress and antioxidative therapies in the pathogenesis of diabetes mellitus.Precise therapeutic interventions against ROS and downstream targets are now possible and provide important new insights into the treatment of diabetes.

The pathogenesis and diagnosis of sepsis post burn injury

Burn is an under-appreciated trauma that is associated with unacceptably high morbidity and mortality.Although the survival rate after devastating burn injuries has continued to increase in previous decades due to medical advances in burn wound care,nutritional and fluid resuscitation and improved infection control practices,there are still large numbers of patients at a high risk of death.One of the most common complications of burn is sepsis,which is defined as“severe organ dysfunction attributed to host’s disordered response to infection”and is the primary cause of death in burn patients.Indeed,burn injuries are accompanied by a series of events that lead to sepsis and multiple organ dysfunction syndrome,such as a hypovolaemic state,immune and inflammatory responses and metabolic changes.Therefore,clear diagnostic criteria and predictive biomarkers are especially important in the prevention and treatment of sepsis and septic shock.In this review,we focus on the pathogenesis of burn wound infection and the post-burn events leading to sepsis.Moreover,the clinical and promising biomarkers of burn sepsis will also be summarized.

Cancer metabolism and tumor microenvironment:fostering each other?

The changes associated with malignancy are not only in cancer cells but also in environment in which cancer cells live.Metabolic reprogramming supports tumor cells’high demand of biogenesis for their rapid proliferation,and helps tumor cells to survive under certain genetic or environmental stresses.Emerging evidence suggests that metabolic alteration is ultimately and tightly associated with genetic changes,in particular the dysregulation of key oncogenic and tumor suppressive signaling pathways.Cancer cells activate HIF signaling even in the presence of oxygen and in the absence of growth factor stimulation.This cancer metabolic phenotype,described firstly by German physiologist Otto Warburg,ensures enhanced glycolytic metabolism for the biosynthesis of macromolecules.The conception of metabolite signaling,i.e.,metabolites are regulators of cell signaling,provides novel insights into how reactive oxygen species(ROS)and other metabolites deregulation may regulate redox homeostasis,epigenetics,and proliferation of cancer cells.Moreover,the unveiling of noncanonical functions of metabolic enzymes,such as the moonlighting functions of phosphoglycerate kinase 1(PGK1),reassures the importance of metabolism in cancer development.The metabolic,microRNAs,and ncRNAs alterations in cancer cells can be sorted and delivered either to intercellular matrix or to cancer adjacent cells to shape cancer microenvironment via media such as exosome.Among them,cancer microenvironmental cells are immune cells which exert profound effects on cancer cells.Understanding of all these processes is a prerequisite for the development of a more effective strategy to contain cancers.

Neoantigens:promising targets for cancer therapy

Recent advances in neoantigen research have accelerated the development and regulatory approval of tumor immunotherapies,including cancer vaccines,adoptive cell therapy and antibody-based therapies,especially for solid tumors.Neoantigens are newly formed antigens generated by tumor cells as a result of various tumor-specific alterations,such as genomic mutation,dysregulated RNA splicing,disordered post-translational modification,and integrated viral open reading frames.Neoantigens are recognized as non-self and trigger an immune response that is not subject to central and peripheral tolerance.The quick identification and prediction of tumor-specific neoantigens have been made possible by the advanced development of next-generation sequencing and bioinformatic technologies.Compared to tumor-associated antigens,the highly immunogenic and tumor-specific neoantigens provide emerging targets for personalized cancer immunotherapies,and serve as prospective predictors for tumor survival prognosis and immune checkpoint blockade responses.The development of cancer therapies will be aided by understanding the mechanism underlying neoantigen-induced anti-tumor immune response and by streamlining the process of neoantigen-based immunotherapies.This review provides an overview on the identification and characterization of neoantigens and outlines the clinical applications of prospective immunotherapeutic strategies based on neoantigens.We also explore their current status,inherent challenges,and clinical translation potential.

NAD+metabolism:pathophysiologic mechanisms and therapeutic potential

Nicotinamide adenine dinucleotide(NAD^(+))and its metabolites function as critical regulators to maintain physiologic processes,enabling the plastic cells to adapt to environmental changes including nutrient perturbation,genotoxic factors,circadian disorder,infection,inflammation and xenobiotics.These effects are mainly achieved by the driving effect of NAD^(+)on metabolic pathways as enzyme cofactors transferring hydrogen in oxidation-reduction reactions.Besides,multiple NAD^(+)-dependent enzymes are involved in physiology either by post-synthesis chemical modification of DNA,RNA and proteins,or releasing second messenger cyclic ADPribose(cADPR)and NAADP^(+).Prolonged disequilibrium of NAD^(+)metabolism disturbs the physiological functions,resulting in diseases including metabolic diseases,cancer,aging and neurodegeneration disorder.In this review,we summarize recent advances in our understanding of the molecular mechanisms of NAD^(+)-regulated physiological responses to stresses,the contribution of NAD^(+)deficiency to various diseases via manipulating cellular communication networks and the potential new avenues for therapeutic intervention.

From purines to purinergic signalling:molecular functions and human diseases

Purines and their derivatives,most notably adenosine and ATP,are the key molecules controlling intracellular energy homoeostasis and nucleotide synthesis.Besides,these purines support,as chemical messengers,purinergic transmission throughout tissues and species.Purines act as endogenous ligands that bind to and activate plasmalemmal purinoceptors,which mediate extracellular communication referred to as“purinergic signalling”.Purinergic signalling is cross-linked with other transmitter networks to coordinate numerous aspects of cell behaviour such as proliferation,differentiation,migration,apoptosis and other physiological processes critical for the proper function of organisms.Pathological deregulation of purinergic signalling contributes to various diseases including neurodegeneration,rheumatic immune diseases,inflammation,and cancer.Particularly,gout is one of the most prevalent purine-related disease caused by purine metabolism disorder and consequent hyperuricemia.Compelling evidence indicates that purinoceptors are potential therapeutic targets,with specific purinergic agonists and antagonists demonstrating prominent therapeutic potential.Furthermore,dietary and herbal interventions help to restore and balance purine metabolism,thus addressing the importance of a healthy lifestyle in the prevention and relief of human disorders.Profound understanding of molecular mechanisms of purinergic signalling provides new and exciting insights into the treatment of human diseases.

Emerging role of tumor cell plasticity in modifying therapeutic response

Resistance to cancer therapy is a major barrier to cancer management.Conventional views have proposed that acquisition of resistance may result from genetic mutations.However,accumulating evidence implicates a key role of non-mutational resistance mechanisms underlying drug tolerance,the latter of which is the focus that will be discussed here.Such non-mutational processes are largely driven by tumor cell plasticity,which renders tumor cells insusceptible to the drug-targeted pathway,thereby facilitating the tumor cell survival and growth.The concept of tumor cell plasticity highlights the significance of re-activation of developmental programs that are closely correlated with epithelial–mesenchymal transition,acquisition properties of cancer stem cells,and transdifferentiation potential during drug exposure.From observations in various cancers,this concept provides an opportunity for investigating the nature of anticancer drug resistance.Over the years,our understanding of the emerging role of phenotype switching in modifying therapeutic response has considerably increased.This expanded knowledge of tumor cell plasticity contributes to developing novel therapeutic strategies or combination therapy regimens using available anticancer drugs,which are likely to improve patient outcomes in clinical practice.

Redox regulation in tumor cell epithelial-mesenchymal transition:molecular basis and therapeutic strategy

Epithelial–mesenchymal transition(EMT)is recognized as a driving force of cancer cell metastasis and drug resistance,two leading causes of cancer recurrence and cancer-related death.It is,therefore,logical in cancer therapy to target the EMT switch to prevent such cancer metastasis and recurrence.Previous reports have indicated that growth factors(such as epidermal growth factor and fibroblast growth factor)and cytokines(such as the transforming growth factor beta(TGF-β)family)are major stimulators of EMT.However,the mechanisms underlying EMT initiation and progression remain unclear.Recently,emerging evidence has suggested that reactive oxygen species(ROS),important cellular secondary messengers involved in diverse biological events in cancer cells,play essential roles in the EMT process in cancer cells by regulating extracellular matrix(ECM)remodeling,cytoskeleton remodeling,cell–cell junctions,and cell mobility.Thus,targeting EMT by manipulating the intracellular redox status may hold promise for cancer therapy.Herein,we will address recent advances in redox biology involved in the EMT process in cancer cells,which will contribute to the development of novel therapeutic strategies by targeting redox-regulated EMT for cancer treatment.

Spontaneous apoptosis of cells in therapeutic stem cell preparation exert immunomodulatory effects through release of phosphatidylserine

Mesenchymal stem cell(MSC)-mediated immunomodulation has been harnessed for the treatment of human diseases,but its underlying mechanism has not been fully understood.Dead cells,including apoptotic cells have immunomodulatory properties.It has been repeatedly reported that the proportion of nonviable MSCs in a MSC therapeutic preparation varied from 5-50%in the ongoing clinical trials.It is conceivable that the nonviable cells in a MSC therapeutic preparation may play a role in the therapeutic effects of MSCs.We found that the MSC therapeutic preparation in the present study had about 5%dead MSCs(DMSCs),characterized by apoptotic cells.Namely,1×10^(6) MSCs in the preparation contained about 5×10^(4) DMSCs.We found that the treatment with even 5×10^(4) DMSCs alone had the equal therapeutic effects as with 1×10^(6) MSCs.This protective effect of the dead MSCs alone was confirmed in four mouse models,including concanavalin A(ConA)-and carbon tetrachloride(CCI4)-induced acute liver injury,LPS-induced lung injury and spinal cord injury.We also found that the infused MSCs died by apoptosis in vivo.Furthermore,the therapeutic effect was attributed to the elevated level of phosphatidylserine(PS)upon the injection of MSCs or DMSCs.The direct administration of PS liposomes(PSLs)mimic apoptotic cell fragments also exerted the protective effects as MSCs and DMSCs.The Mer tyrosine kinase(MerTK)deficiency or the knockout of chemokine receptor C-C motif chemokine receptor 2(CCR2)reversed these protective effects of MSCs or DMSCs.These results revealed that DMSCs alone in the therapeutic stem cell preparation or the apoptotic cells induced in vivo may exert the same immunomodulatory property as the'living MSCs preparation"through releasing PS,which was further recognized by MerTK and participated in modulating immune cells.

Epigenetic regulation in major depression and other stressrelated disorders: molecular mechanisms, clinical relevance and therapeutic potential

Major depressive disorder(MDD)is a chronic,generally episodic and debilitating disease that affects an estimated 300 million people worldwide,but its pathogenesis is poorly understood.The heritability estimate of MDD is 30–40%,suggesting that genetics alone do not account for most of the risk of major depression.Another factor known to associate with MDD involves environmental stressors such as childhood adversity and recent life stress.Recent studies have emerged to show that the biological impact of environmental factors in MDD and other stress-related disorders is mediated by a variety of epigenetic modifications.These epigenetic modification alterations contribute to abnormal neuroendocrine responses,neuroplasticity impairment,neurotransmission and neuroglia dysfunction,which are involved in the pathophysiology of MDD.Furthermore,epigenetic marks have been associated with the diagnosis and treatment of MDD.The evaluation of epigenetic modifications holds promise for further understanding of the heterogeneous etiology and complex phenotypes of MDD,and may identify new therapeutic targets.Here,we review preclinical and clinical epigenetic findings,including DNA methylation,histone modification,noncoding RNA,RNA modification,and chromatin remodeling factor in MDD.In addition,we elaborate on the contribution of these epigenetic mechanisms to the pathological trait variability in depression and discuss how such mechanisms can be exploited for therapeutic purposes.

Overcoming cancer therapeutic bottleneck by drug repurposing

Ever present hurdles for the discovery of new drugs for cancer therapy have necessitated the development of the alternative strategy of drug repurposing,the development of old drugs for new therapeutic purposes.This strategy with a cost-effective way offers a rare opportunity for the treatment of human neoplastic disease,facilitating rapid clinical translation.With an increased understanding of the hallmarks of cancer and the development of various data-driven approaches,drug repurposing further promotes the holistic productivity of drug discovery and reasonably focuses on target-defined antineoplastic compounds.The“treasure trove”of non-oncology drugs should not be ignored since they could target not only known but also hitherto unknown vulnerabilities of cancer.Indeed,different from targeted drugs,these old generic drugs,usually used in a multi-target strategy may bring benefit to patients.In this review,aiming to demonstrate the full potential of drug repurposing,we present various promising repurposed non-oncology drugs for clinical cancer management and classify these candidates into their proposed administration for either mono-or drug combination therapy.We also summarize approaches used for drug repurposing and discuss the main barriers to its uptake.

Repurposing econazole as a pharmacological autophagy inhibitor to treat pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma(PDAC)is characterized by the highest mortality among carcinomas.The pathogenesis of PDAC requires elevated autophagy,inhibition of which using hydroxychloroquine has shown promise.However,current realization is impeded by its suboptimal use and unpredictable toxicity.Attempts to identify novel autophagy-modulating agents from already approved drugs offer a rapid and accessible approach.Here,using a patient-derived organoid model,we performed a comparative analysis of therapeutic responses among various antimalarial/fungal/parasitic/viral agents,through which econazole(ECON),an antifungal compound,emerged as the top candidate.Further testing in cell-line and xenograft models of PDAC validated this activity,which occurred as a direct consequence of dysfunctional autophagy.More specifically,ECON boosted autophagy initiation but blocked lysosome biogenesis.RNA sequencing analysis revealed that this autophagic induction was largely attributed to the altered expression of activation transcription factor 3(ATF3).Increased nuclear import of ATF3 and its transcriptional repression of inhibitor of differentiation-1(ID-1)led to inactivation of the AKT/mammalian target of rapamycin(m TOR)pathway,thus giving rise to autophagosome accumulation in PDAC cells.The magnitude of the increase in autophagosomes was sufficient to elicit ER stress-mediated apoptosis.Furthermore,ECON,as an autophagy inhibitor,exhibited synergistic effects with trametinib on PDAC.This study provides direct preclinical and experimental evidence for the therapeutic efficacy of ECON in PDAC treatment and reveals a mechanism whereby ECON inhibits PDAC growth.

Histones released by NETosis enhance the infectivity of SARS-CoV-2 by bridging the spike protein subunit 2 and sialic acid on host cells

Neutrophil extracellular traps(NETs)can capture and kill viruses,such as influenza viruses,human immunodeficiency virus(HIV),and respiratory syncytial virus(RSV),thus contributing to host defense.Contrary to our expectation,we show here that the histones released by NETosis enhance the infectivity of SARS-CoV-2,as found by using live SARS-CoV-2 and two pseudovirus systems as well as a mouse model.The histone H3 or H4 selectively binds to subunit 2 of the spike(S)protein,as shown by a biochemical binding assay,surface plasmon resonance and binding energy calculation as well as the construction of a mutant S protein by replacing four acidic amino acids.Sialic acid on the host cell surface is the key molecule to which histones bridge subunit 2 of the S protein.Moreover,histones enhance cell-cell fusion.Finally,treatment with an inhibitor of NETosis,histone H3 or H4,or sialic acid notably affected the levels of sgRNA copies and the number of apoptotic cells in a mouse model.These findings suggest that SARS-CoV-2 could hijack histones from neutrophil NETosis to promote its host cell attachment and entry process and may be important in exploring pathogenesis and possible strategies to develop new effective therapies for COVID-19.

BCL7C suppresses ovarian cancer growth by inactivating mutant p53

B-cell CLL/lymphoma 7 protein family member C (BCL7C) located at chromosome 16p11.2 shares partial sequence homology with the other two family members, BCL7A and BCL7B. Its role in cancer remains completely unknown. Here, we report our finding of its tumor-suppressive role in ovarian cancer. Supporting this is that BCL7C is downregulated in human ovarian carcinomas, and its underexpression is associated with unfavorable prognosis of ovarian cancer as well as some other types of human cancers. Also, ectopic BCL7C restrains cell proliferation and invasion of ovarian cancer cells. Consistently, depletion of BCL7C reduces apoptosis and promotes cell proliferation and invasion of these cancer cells. Mechanistically, BCL7C suppresses mutant p53-mediated gene transcription by binding to mutant p53, while knockdown of BCL7C enhances the expression of mutant p53 target genes in ovarian cancer cells. Primary ovarian carcinomas that sustain low levels of BCL7C often show the elevated expression of mutant p53 target genes. In line with these results, BCL7C abrogates mutant p53-induced cell proliferation and invasion, but had no impact on proliferation and invasion of cancer cells with depleted p53 or harboring wild-type p53. Altogether, our results demonstrate that BCL7C can act as a tumor suppressor to prevent ovarian tumorigenesis and progression by counteracting mutant p53 activity.

Targeting PSAT1 to mitigate metastasis in tumors with p53-72Pro variant

The single-nucleotide polymorphism(SNP)of p53,in particular the codon 72 variants,has recently been implicated as a critical regulator in tumor progression.However,the underlying mechanism remains elusive.Here we found that cancer cells carrying codon 72-Pro variant of p53 showed impaired metastatic potential upon serine supplementation.Proteome-wide mapping of p53-interacting proteins uncovered a specific interaction of the codon 72 proline variant(but not p5372R)with phosphoserine aminotransferase 1(PSAT1).Interestingly,p53^(72P)-PSAT1 interaction resulted in dissociation of peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α)that otherwise bound to p53^(72P),leading to subsequent nuclear translocation of PGC-1αand activation of oxidative phosphorylation(OXPHOS)and tricarboxylic acid(TCA)cycle.Depletion of PSAT1 restored p53^(72P)-PGC-1αinteraction and impeded the OXPHOS and TCA function,resulting in mitochondrial dysfunction and metastasis suppression.Notably,pharmacological targeting the PSAT1-p53^(72P)interaction by aminooxyacetic acid(AOA)crippled the growth of liver cancer cells carrying the p53^(72P)variant in both in vitro and patient-derived xenograft models.Moreover,AOA plus regorafenib,an FDA-proved drug for hepatocellular carcinoma and colorectal cancer,achieved a better anti-tumor effect on tumors carrying the p53^(72P)variant.Therefore,our findings identified a gain of function of the p53^(72P)variant on mitochondrial function and provided a promising precision strategy to treat tumors vulnerable to p53^(72P)-PSAT1 perturbation.

Transcriptional pausing induced by ionizing radiation enables the acquisition of radioresistance in nasopharyngeal carcinoma

Lesions on the DNA template can impact transcription via distinct regulatory pathways.Ionizing radiation(IR)as the mainstay modality for many malignancies elicits most of the cytotoxicity by inducing a variety of DNA damages in the genome.How the IR treatment alters the transcription cycle and whether it contributes to the development of radioresistance remain poorly understood.Here,we report an increase in the paused RNA polymerase II(RNAPII),as indicated by the phosphorylation at serine 5 residue of its C-terminal domain,in recurrent nasopharyngeal carcinoma(NPC)patient samples after IR treatment and cultured NPC cells developing IR resistance.Reducing the pool of paused RNAPII by either inhibiting TFIIH-associated CDK7 or stimulating the positive transcription elongation factor b,a CDK9-CycT1 heterodimer,attenuates IR resistance of NPC cells.Interestingly,the poly(ADP-ribosyl)ation of CycT1,which disrupts its phase separation,is elevated in the IR-resistant cells.Mutation of the major poly(ADP-ribosyl)ation sites of CycT1 decreases RNAPII pausing and restores IR sensitivity.Genome-wide chromatin immunoprecipitation followed by sequencing analyses reveal that several genes involved in radiation response and cell cycle control are subject to the regulation imposed by the paused RNAPII.Particularly,we identify the NIMA-related kinase NEK7 under such regulation as a new radioresistancefactor,whose downregulation results in the increased chromosome instability,enabling the development of IR resistance.Overall,our results highlight a novel link between the alteration in the transcription cycle and the acquisition of IR resistance,opening up new opportunities to increase the efficacy of radiotherapy and thwart radioresistance in NpC.

Correction: Spontaneous apoptosis of cells in therapeutic stemcell preparation exert immunomodulatory effects throughrelease of phosphatidylserine

After online publication of the article1,the authors noticed one inadvertent mistake in Fig.5a that needs to be corrected.In detail,the pathological picture of PBS group in Fig.5a is inadvertently duplicated as the image of PBS group in Fig.7b in the main text.This duplication is a result of errors in figure assembly,and the correct Fig.5 is provided as follows.The key findings of the article are not affected by these corrections.