BACKGROUND With the increasing of the global aging population,healthy aging and prevention of age-related diseases have become increasingly important.The liver,a vital organ involved in metabolism,detoxification,diges...BACKGROUND With the increasing of the global aging population,healthy aging and prevention of age-related diseases have become increasingly important.The liver,a vital organ involved in metabolism,detoxification,digestion,and immunity,holds a pivotal role in the aging process of organisms.Although extensive research on liver aging has been carried out,no bibliometric analysis has been conducted to evaluate the scientific progress in this area.AIM To analyze basic knowledge,development trends,and current research frontiers in the field via bibliometric methods.METHODS We conducted bibliometric analyses via a range of analytical tools including Python,the bibliometrix package in R,CiteSpace,and VOSviewer.We retrieved publication data on liver aging research from the Web of Science Core Collection Database.A scientific knowledge map was constructed to display the contributions from different authors,journals,countries,institutions,as well as patterns of co-occurrence keywords and co-cited references.Additionally,gene regulation pathways associated with liver aging were analyzed via the STRING database.RESULTS We identified 4288 articles on liver aging,authored by 24034 contributors from 4092 institutions across 85 countries.Notably,the years 1991 and 2020 presented significant bursts in publication output.The United States led in terms of publications(n=1008,25.1%),citations(n=55205),and international collaborations(multiple country publications=214).Keywords such as“lipid metabolism”,“fatty liver disease”,“inflammation”,“liver fibrosis”and“target”were prominent,highlighting the current research hotspots.Notably,the top 64 genes,each of which appeared in at least 8 articles,were involved in pathways essential for cell survival and aging,including the phosphatidylinositol 3-kinase/protein kinase B,Forkhead box O and p53 signaling pathways.CONCLUSION This study highlights key areas of liver aging and offers a comprehensive overview of research trends,as well as insights into potential value for collaborative pursuits and clinical implementations.展开更多
Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were establi...Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were established and used to conduct integrative targetingactive enhancer histone H3 lysine 27 acetylation(H3K27ac)chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency.Notably,LBP^(-/-)reduced the inflammatory response but markedly aggravated high-fat diet(HFD)-induced NAFLD in rats,with pronounced alterations in the histone acetylome and regulatory transcriptome.In total,1128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type(WT)and LBP^(-/-)NAFLD rats.Based on integrative analysis,CCAAT/enhancer-binding proteinβ(C/EBPβ)was identified as a pivotal transcription factor(TF)and contributor to dysregulated histone acetylome H3K27ac,and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD.This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPβand functional gene SCD as potential regulators and therapeutic targets.展开更多
Aging is a natural phenomenon characterized by a progressive decline in physiological integrity,leading to a deterioration of cognitive function and increasing the risk of suffering from chronic-degenerative diseases,...Aging is a natural phenomenon characterized by a progressive decline in physiological integrity,leading to a deterioration of cognitive function and increasing the risk of suffering from chronic-degenerative diseases,including cardiovascular diseases,osteoporosis,cancer,diabetes,and neurodegeneration.Aging is considered the major risk factor for Parkinson’s and Alzheimer’s disease develops.Likewise,diabetes and insulin resistance constitute additional risk factors for developing neurodegenerative disorders.Currently,no treatment can effectively reverse these neurodegenerative pathologies.However,some antidiabetic drugs have opened the possibility of being used against neurodegenerative processes.In the previous framework,Vanadium species have demonstrated a notable antidiabetic effect.Our research group evaluated polyoxidovanadates such as decavanadate and metforminium-decavanadate with preventive and corrective activity on neurodegeneration in brain-specific areas from rats with metabolic syndrome.The results suggest that these polyoxidovanadates induce neuronal and cognitive restoration mechanisms.This review aims to describe the therapeutic potential of polyoxidovanadates as insulin-enhancer agents in the brain,constituting a therapeutic alternative for aging and neurodegenerative diseases.展开更多
Background:Pig organ xenotransplantation is a potential solution for the severe organ shortage in clinic,while immunogenic genes need to be eliminated to improve the immune compatibility between humans and pigs.Curren...Background:Pig organ xenotransplantation is a potential solution for the severe organ shortage in clinic,while immunogenic genes need to be eliminated to improve the immune compatibility between humans and pigs.Current knockout strategies are mainly aimed at the genes causing hyperacute immune rejection(HAR)that occurs in the first few hours while adaptive immune reactions orchestrated by CD4 T cell thereafter also cause graft failure,in which process the MHCⅡmolecule plays critical roles.Methods:Thus,we generate a 4-gene(GGTA1,CMAH,β4GalNT2,and CIITA)knockout pig by CRISPR/Cas9 and somatic cell nuclear transfer to compromise HAR and CD4 T cell reactions simultaneously.Results:We successfully obtained 4KO piglets with deficiency in all alleles of genes,and at cellular and tissue levels.Additionally,the safety of our animals after gene editing was verified by using whole-genome sequencing and karyotyping.Piglets have survived for more than one year in the barrier,and also survived for more than 3 months in the conventional environment,suggesting that the piglets without MHCⅡcan be raised in the barrier and then gradually mated in the conventional environment.Conclusions:4KO piglets have lower immunogenicity,are safe in genomic level,and are easier to breed than the model with both MHCⅠandⅡdeletion.展开更多
Meiosis is a highly complex process significantly influenced by transcriptional regulation.However,studies on the mechanisms that govern transcriptomic changes during meiosis,especially in prophase I,are limited.Here,...Meiosis is a highly complex process significantly influenced by transcriptional regulation.However,studies on the mechanisms that govern transcriptomic changes during meiosis,especially in prophase I,are limited.Here,we performed single-cell ATAC-seq of human testis tissues and observed reprogramming during the transition from zygotene to pachytene spermatocytes.This event,conserved in mice,involved the deactivation of genes associated with meiosis after reprogramming and the activation of those related to spermatogenesis before their functional onset.Furthermore,we identified 282 transcriptional regulators(TRs)that underwent activation or deactivation subsequent to this process.Evidence suggested that physical contact signals from Sertoli cells may regulate these TRs in spermatocytes,while secreted ENHO signals may alter metabolic patterns in these cells.Our results further indicated that defective transcriptional reprogramming may be associated with non-obstructive azoospermia(NOA).This study revealed the importance of both physical contact and secreted signals between Sertoli cells and germ cells in meiotic progression.展开更多
Timothy (Phleum pretense L.) pastures of 3 Total mixed ration (TMR) centers in Hokkaido were selected, the first cutting grasses were continuously collected from the same pastures on different harvest days over 4 year...Timothy (Phleum pretense L.) pastures of 3 Total mixed ration (TMR) centers in Hokkaido were selected, the first cutting grasses were continuously collected from the same pastures on different harvest days over 4 years (2011-2014), and changes in the water soluble carbohydrates (WSC) content were analyzed to investigate the relationship with weather conditions. The harvest days in the 4-year period were June 17-22, June 24-26, June 27-30, and July 2-5, and grasses on these dates were designated as the harvest date groups. The weather data during the cutting period in each year were utilized. The WSC content tended to change yearly and it was significantly lower in the 4 groups (67.3 - 82.1 g/kg DM) in 2011 than in the groups (101.5 - 130.3 g/kg DM) in 2013 excluding the June 24-26 group (P < 0.05, P < 0.01). The WSC content tended to increase as the harvest date progressed in 2011-2013 and it significantly increased even though the harvest date was delayed only in 2013 (P < 0.01). It was suggested that differences in the WSC content among the years were related to the weather condition and dry matter yield of the grass.展开更多
The key regulators and regeneration-associated genes involved in axonal regeneration of neurons after injury have not been clarified.In high-throughput sequencing,various factors influence the final sequencing results...The key regulators and regeneration-associated genes involved in axonal regeneration of neurons after injury have not been clarified.In high-throughput sequencing,various factors influence the final sequencing results,including the number and size of cells,the depth of sequencing,and the method of cell separation.There is still a lack of research on the detailed molecular expression profile during the regeneration of dorsal root ganglion neuron axon.In this study,we performed lase r-capture microdissection coupled with RNA sequencing on dorsal root ganglion neurons at 0,3,6,and 12 hours and 1,3,and 7 days after sciatic nerve crush in rats.We identified three stages after dorsal root ganglion injury:early(3-12 hours),pre-regeneration(1 day),and regeneration(3-7 days).Gene expression patterns and related function enrichment res ults showed that one module of genes was highly related to axonal regeneration.We verified the up-regulation of activating transcription factor 3(Atf3),Kruppel like factor 6(Klf6),AT-rich inte raction domain 5A(Arid5α),CAMP responsive element modulator(Crem),and FOS like 1,AP-1 transcription factor Subunit(Fosl1) in dorsal root ganglion neurons after injury.Suppressing these transcription factors(Crem,Arid5o,Fosl1 and Klf6) reduced axonal regrowth in vitro.As the hub transcription factor,Atf3 showed higher expression and activity at the preregeneration and regeneration stages.G protein-coupled estrogen receptor 1(Gper1),inte rleukin 12a(Il12α),estrogen receptor 1(ESR1),and interleukin 6(IL6) may be upstream factors that trigger the activation of Atf3 during the repair of axon injury in the early stage.Our study presents the detailed molecular expression profile during axonal regeneration of dorsal root ganglion neurons after peripheral nerve injury.These findings may provide reference for the clinical screening of molecular targets for the treatment of peripheral nerve injury.展开更多
Neurotrophic factors,particularly nerve growth factor,enhance neuronal regeneration.However,the in vivo applications of nerve growth factor are largely limited by its intrinsic disadvantages,such as its short biologic...Neurotrophic factors,particularly nerve growth factor,enhance neuronal regeneration.However,the in vivo applications of nerve growth factor are largely limited by its intrinsic disadvantages,such as its short biological half-life,its contribution to pain response,and its inability to cross the blood-brain barrier.Considering that let-7(human miRNA)targets and regulates nerve growth factor,and that let-7 is a core regulator in peripheral nerve regeneration,we evaluated the possibilities of let-7 application in nerve repair.In this study,anti-let-7a was identified as the most suitable let-7 family molecule by analyses of endogenous expression and regulatory relationship,and functional screening.Let-7a antagomir demonstrated biosafety based on the results of in vivo safety assessments and it entered into the main cell types of the sciatic nerve,including Schwann cells,fibroblasts and macrophages.Use of hydrogel effectively achieved controlled,localized,and sustained delivery of let-7a antagomir.Finally,let-7a antagomir was integrated into chitosan conduit to construct a chitosan-hydrogel scaffold tissue-engineered nerve graft,which promoted nerve regeneration and functional recovery in a rat model of sciatic nerve transection.Our study provides an experimental basis for potential in vivo application of let-7a.展开更多
BACKGROUND Restoration of immune homeostasis by targeting the balance between memory T helper(mTh)cells and memory follicular T helper(mTfh)cells is a potential therapeutic strategy against ulcerative colitis(UC).Beca...BACKGROUND Restoration of immune homeostasis by targeting the balance between memory T helper(mTh)cells and memory follicular T helper(mTfh)cells is a potential therapeutic strategy against ulcerative colitis(UC).Because of its anti-inflammatory and immunomodulatory properties,curcumin(Cur)is a promising drug for UC treatment.However,fewer studies have demonstrated whether Cur can modulate the mTh/mTfh subset balance in mice with colitis.AIM To explore the potential mechanism underlying Cur-mediated alleviation of colitis induced by dextran sulfate sodium(DSS)in mice by regulating the mTh and mTfh immune homeostasis.METHODS Balb/c mice were administered 3%and 2%DSS to establish the UC model and treated with Cur(200 mg/kg/d)by gavage on days 11-17.On the 18th d,all mice were anesthetized and euthanized,and the colonic length,colonic weight,and colonic weight index were evaluated.Histomorphological changes in the mouse colon were observed through hematoxylin-eosin staining.Levels of Th/mTh and Tfh/mTfh cell subsets in the spleen were detected through flow cytometry.Western blotting was performed to detect SOCS-1,SOCS-3,STAT3,p-STAT3,JAK1,p-JAK1,and NF-κB p65 protein expression levels in colon tissues.RESULTS Cur effectively mitigates DSS-induced colitis,facilitates the restoration of mouse weight and colonic length,and diminishes the colonic weight and colonic weight index.Simultaneously,it hinders ulcer development and inflammatory cell infiltration in the colonic mucous membrane.While the percentage of Th1,mTh1,Th7,mTh7,Th17,mTh17,Tfh1,mTfh1,Tfh7,mTfh7,Tfh17,and mTfh17 cells decreased after Cur treatment of the mice for 7 d,and the frequency of mTh10,Th10,mTfh10,and Tfh10 cells in the mouse spleen increased.Further studies revealed that Cur administration prominently decreased the SOCS-1,SOCS-3,STAT3,p-STAT3,JAK1,p-JAK1,and NF-κB p65 protein expression levels in the colon tissue.CONCLUSION Cur regulated the mTh/mTfh cell homeostasis to reduce DSS-induced colonic pathological damage,potentially by suppressing the JAK1/STAT3/SOCS signaling pathway.展开更多
Reproduction is subtlety regulated by the hypothalamic-pituitary-gonad(HPG)axis in vertebrates.Pituitary gland is the center of the HPG axis,while pituitary gonadotropins follicle stimulating hormone(FSH)and luteinizi...Reproduction is subtlety regulated by the hypothalamic-pituitary-gonad(HPG)axis in vertebrates.Pituitary gland is the center of the HPG axis,while pituitary gonadotropins follicle stimulating hormone(FSH)and luteinizing hormone(LH)were identified the key elements of the HPG axis in teleost and mammal.Morphology,cell lines,and gonadotropins cell localization of female turbot and mouse pituitary were determined at mature stage to illustrate the anatomical difference and cell characteristics in this study.Results show that turbot pituitary is chicken heart-shaped,dorsoventral,located on the ventral surface of the diencephalon.The mouse pituitary is oval,located in the pituitary fossa of the sella turcica at the skull base.Two well-distinguished areas adenohypophysis(AH)and neurohypophysis(NH)in pituitary were identified in turbot and mouse.Turbot AH comprised the rostral pars distalis(RPD),proximal pars distalis(PPD),and pars intermedia(PI).NH was not pronounced and with finger-like protrusions into PPD.However,mouse AH only comprised the pars distalis(PD)and PI.NH distribution was semicircular.Three main types of cells(acidophilic,basophilic,and chromophobic cells)were distributed in the mouse PD region,whereas appeared in the turbot PPD,RPD,and PI.Moreover,the percentage of mouse chromophobic and basophilic cells was higher and lower than that of turbot,respectively.The diameter of the aforementioned three cells in the mouse was significantly higher than turbot.fshβ-and lhβ-immunoreactive signals were identified in turbot-distinct pituitary cells that primarily occupied the peripheral and central regions of AH.However,mouse fsh-and lh-immunoreactive cells were expressed in the same cells and present in the PD.These results demonstrate the significantly difference of pituitary morphology,cell lines and gonadotropins(fshβand lhβ)location in female turbot and mouse.These differences help for fully understand the evolution and endocrinological functions of pituitary.展开更多
Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammator...Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.展开更多
The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a new...The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid (RA) was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin (STZ)-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.展开更多
Objective To study the effect of electromagnetic pulse (EMP) exposure on the permeability of blood-testicle barrier (BTB) in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with...Objective To study the effect of electromagnetic pulse (EMP) exposure on the permeability of blood-testicle barrier (BTB) in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with 2 seconds interval. The mice were injected with 2% Evans Blue solution through caudal vein at different time points after exposure, and the permeability of BTB was monitored using a fluorescence microscope. The testis sample for the transmission electron microscopy was prepared at 2 h after EMP exposure. The permeability of BTB in mice was observed by using Evans Blue tracer and lanthanum nitrate tracer. Results After exposure, cloudy Evans Blue was found in the testicle convoluted seminiferous tubule of mice. Lanthanum nitrate was observed not only between testicle spermatogonia near seminiferous tubule wall and sertoli cells, but also between sertoli cells and primary spermatocyte or secondary spermatocyte. In contrast, lanthanum nitrate in control group was only found in the testicle sertoli cells between seminiferous tubule and near seminifdrous tubule wall. Conclusion EMP exposure could increase the permeability of BTB in the mice.展开更多
Litter size and birth weights are limited by uterine capacity, defined as the ability of the uterus to maintain the appropriate development of some number of conceptuses. Uterine capacity is the result of the combined...Litter size and birth weights are limited by uterine capacity, defined as the ability of the uterus to maintain the appropriate development of some number of conceptuses. Uterine capacity is the result of the combined effects of uterine, placental and embryo/fetal function. The number of living conceptuses that the uterus is capable of supporting is greater during early gestation compared to later gestation. Plots of log fetal weight versus log placental weight also indicate that fetal weights are less sensitive to reduced placental weight (and therefore reduced intrauterine space) in early gestation compared to late gestation. However, even in late gestation, mechanisms still exist that maintain fetal growth when the size of the placenta is reduced. One such mechanism is likely to be improved development of the folded placental-epithelial/maternal-epithelial bilayer. Fold depth, and therefore the maternal fetal interactive surface, increases as gestation advances and is greater in placenta from smal fetuses. On the fetal side of the placenta, the epithelial bilayer is embedded in stromal tissue. Glycosaminoglycans are major components of stroma, including hyaluronan and heparan sulfate. Hyaluronidases and heparanases are present within placental tissues, and likely play roles in modification of stromal components to facilitate fold development. Glycosaminoglycans are polymers of forms of glucose (glucosamine, glucuronic acid, iduronic acid) suggesting that glycosaminoglycan synthesis may compete with the glucose needs of the developing fetus. Pig conceptuses are fructogenic, such that a substantial portion of glucose transferred from mother to fetus is converted to fructose. Fructose is an intermediate product in the synthesis of glucosamine from glucose, and glucosamine is linked to regulation of trophoblast cell proliferation through regulation of mTOR. These findings suggest a link between glucose, fructose, glucosamine synthesis, GAG production, and placental morphogenesis, but the details of these interactions remain unclear. In addition, recent placental epithelial transcriptome analysis identified several glucose, amino acid, lipid, vitamin, mineral and hormone transporter mechanisms within the placenta. Further elucidation of mechanisms of placental morphogenesis and solute transport could provide clues to improving nutrient transport to the pig fetus, potentially increasing litter size and piglet birth weights.展开更多
Lysozyme is a naturally occurring enzyme found in bodily secretions such as tears, saliva, and milk. It functions as an antimicrobial agent by cleaving the peptidoglycan component of bacterial cell walls, which leads ...Lysozyme is a naturally occurring enzyme found in bodily secretions such as tears, saliva, and milk. It functions as an antimicrobial agent by cleaving the peptidoglycan component of bacterial cell walls, which leads to cell death. Antibiotics are also antimicrobials and have been fed at subtherapeutic levels to swine as growth promoters. These compounds benefit swine producers by minimizing production losses by increasing feed efficiency and decreasing susceptibility to bacterial infection and disease. This manuscript reviews the knowledge of the effects of lysozyme, as compared to traditional subtherapeutic antibiotics in swine feed, on pig performance and health. It is clear from decades of studies that antibiotic use in feeds increases pig performance, particularly in the nursery. Similarly, lysozyme, as a feed additive, increases growth and feed efficiency. While the mechanism by which antibiotics and lysozyme improve performance is not clearly understood, both of these feed additives improve gastrointestinal health, improve the metabolic profile, and alter the gastrointestinal bacteria ecology of swine. Therefore, lysozyme is a suitable alternative to growth-promoting subtherapeutic antibiotic use in swine feed.展开更多
Recovery from injury to the peripheral nervous system is different from that of the central nervous system in that it can lead to gene reprogramming that can induce the expression of a series of regeneration-associate...Recovery from injury to the peripheral nervous system is different from that of the central nervous system in that it can lead to gene reprogramming that can induce the expression of a series of regeneration-associated genes.This eventually leads to axonal regeneration of injured neurons.Although some regeneration-related genes have been identified,the regulatory network underlying axon regeneration remains largely unknown.To explore the regulator of axon regeneration,we performed RNA sequencing of lumbar L4 and L5 dorsal root ganglion(DRG)neurons at different time points(0,3,6,12 hours,1,3 and 7 days)after rat sciatic nerve crush.The isolation of neurons was carried out by laser capture microscopy combined with NeuN immunofluorescence staining.We found 1228 differentially expressed genes in the injured sciatic nerve tissue.The hub genes within these differentially expressed genes include Atf3,Jun,Myc,Ngf,Fgf2,Ezh2,Gfap and Il6.We verified that the expression of the enhancer of zeste homologue 2 gene(Ezh2)was up-regulated in DRG neurons after injury,and this up-regulation differed between large-and small-sized dorsal root ganglion neurons.To investigate whether the up-regulation of Ezh2 impacts axonal regeneration,we silenced Ezh2 with siRNA in cultured DRG neurons and found that the growth of the newborn axons was repressed.In our investigation into the regulatory network of Ezh2 by interpretive phenomenal analysis,we found some regulators of Ezh2(including Erk,Il6 and Hif1a)and targets(including Atf3,Cdkn1a and Smad1).Our findings suggest that Ezh2,as a nerve regeneration-related gene,participates in the repair of the injured DRG neurons,and knocking down the Ezh2 in vitro inhibits the axonal growth of DRG neurons.All the experimental procedures approved by the Administration Committee of Experimental Animals of Jiangsu Province of China(approval No.S20191201-201)on March 21,2019.展开更多
PTEN, a negative regulator of the phosphatidylinositol-3-kinase/AKT pathway, is an important modulator of insulin signaling. To determine the metabolic function of pancreatic Pten, we generated pancreas-specific Pten ...PTEN, a negative regulator of the phosphatidylinositol-3-kinase/AKT pathway, is an important modulator of insulin signaling. To determine the metabolic function of pancreatic Pten, we generated pancreas-specific Pten knockout (PPKO) mice. PPKO mice had enlarged pancreas and elevated proliferation of acinar cells. They also exhibited hypoglycemia, hypoinsulinemia, and altered amino metabolism. Notably, PPKO mice showed delayed onset of streptozotocin (STZ)-induced diabetes and sex-biased resistance to high-fat-diet (HFD)-induced diabetes. To investigate the mechanism for the resistance to HFD-induced hyperglycemia in PPKO mice, we evaluated AKT phosphorylation in major insulin-responsive tissues: the liver, muscle, and fat. We found that Pten loss in the pancreas causes the elevation of AKT signaling in the liver. The phosphorylation of AKT and its downstream substrate GSK3β was increased in the liver of PPKO mice, while PTEN level was decreased without detectable excision of Pten allele in the liver of PPKO mice. Proteomics analysis revealed dramatically decreased level of 78-kDa glucose-regulated protein (GRP78) in the liver of PPKO mice, which may also contribute to the lower blood glucose level of PPKO mice fed with HFD. Together, our findings reveal a novel response in the liver to pancreatic defect in metabolic regulation, adding a new dimension to understanding diabetes resistance.展开更多
In the present study,Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error cou...In the present study,Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error counts,indicating a learning and memory disorder.After treatment with 30,60,90,120,or 200 mg/kg lithium chloride,the learning and memory abilities of the Fmr1 KO mice were significantly ameliorated,in particular,the 200 mg/kg lithium chloride treatment had the most significant effect.Western blot analysis showed that lithium chloride significantly enhanced the expression of phosphorylated glycogen synthase kinase 3 beta,an inactive form of glycogen synthase kinase 3 beta,in the cerebral cortex and hippocampus of the Fmr1 KO mice.These results indicated that lithium chloride improved learning and memory in the Fmr1 KO mice,possibly by inhibiting glycogen synthase kinase 3 beta activity.展开更多
T cells are derived from progenitor thymocytes, of which only a minority receive the appropriate TCR signal, undergo positive selection and mature. Owing to the very short lifespan of thymocytes, the prerequisite for ...T cells are derived from progenitor thymocytes, of which only a minority receive the appropriate TCR signal, undergo positive selection and mature. Owing to the very short lifespan of thymocytes, the prerequisite for posi- tive selection is survival. TCR signal-induced Bcl-2 expression is believed to play a dominant role in the survival of positively selecting thymocytes, but how Bcl-2 is directly regulated is unknown. Here we report that the immediate early gene (IEG) c-Fos can stimulate the expression of Bcl-2, depending on a specific AP-l-binding site in the Bcl-2 promoter. In c-Fos transgenic (Fos-Tg) mice, c-Fos binds to this site and promotes the expression of Bcl-2. As a result, Fos-Tg thymocytes exhibited enhanced survival, and more mature single-positive (SP) thymocytes were generated, even on a unique TCR background. The TCR repertoire remained normal in Fos-Tg mice. Our results identified c-Fos as the mediator of the stimulatory effect of TCR signaling on Bcl-2 expression. Therefore, c-Fos, as an IEG, because of its early response ability, can quickly rescue the survival of short-lived thymocytes during positive selection. Our results provide novel insight into the mechanism regulating the survival of positively selecting thymocytes.展开更多
基金Supported by the National Natural Science Foundation of China,No.82271587,No.82172600,No.81972270,No.91849108,and No.82200665the National Key R&D Program of China,No.2022YFC3401601+2 种基金the Zhejiang Provincial Natural Science Foundation of China,No.LY22H030009the Zhejiang Provincial Science and Technology Program of Traditional Chinese Medicine,No.2023ZL480the Medical and Health Research Project of Zhejiang Province,No.2023RC153.
文摘BACKGROUND With the increasing of the global aging population,healthy aging and prevention of age-related diseases have become increasingly important.The liver,a vital organ involved in metabolism,detoxification,digestion,and immunity,holds a pivotal role in the aging process of organisms.Although extensive research on liver aging has been carried out,no bibliometric analysis has been conducted to evaluate the scientific progress in this area.AIM To analyze basic knowledge,development trends,and current research frontiers in the field via bibliometric methods.METHODS We conducted bibliometric analyses via a range of analytical tools including Python,the bibliometrix package in R,CiteSpace,and VOSviewer.We retrieved publication data on liver aging research from the Web of Science Core Collection Database.A scientific knowledge map was constructed to display the contributions from different authors,journals,countries,institutions,as well as patterns of co-occurrence keywords and co-cited references.Additionally,gene regulation pathways associated with liver aging were analyzed via the STRING database.RESULTS We identified 4288 articles on liver aging,authored by 24034 contributors from 4092 institutions across 85 countries.Notably,the years 1991 and 2020 presented significant bursts in publication output.The United States led in terms of publications(n=1008,25.1%),citations(n=55205),and international collaborations(multiple country publications=214).Keywords such as“lipid metabolism”,“fatty liver disease”,“inflammation”,“liver fibrosis”and“target”were prominent,highlighting the current research hotspots.Notably,the top 64 genes,each of which appeared in at least 8 articles,were involved in pathways essential for cell survival and aging,including the phosphatidylinositol 3-kinase/protein kinase B,Forkhead box O and p53 signaling pathways.CONCLUSION This study highlights key areas of liver aging and offers a comprehensive overview of research trends,as well as insights into potential value for collaborative pursuits and clinical implementations.
基金supported by the National Natural Science Foundation of China(81971875,82300661)Natural Science Foundation of Anhui province(2308085QH246)+3 种基金Natural Science Foundation of the Anhui Higher Education Institutions(KJ2021A0205)Basic and Clinical Cooperative Research Program of Anhui Medical University(2019xkjT002,2019xkjT022,2022xkjT013)Talent Training Program,School of Basic Medical Sciences,Anhui Medical University(2022YPJH102)National College Students Innovation and Entrepreneurship Training Program of China(202210366024)。
文摘Non-alcoholic fatty liver disease(NAFLD)is associated with mutations in lipopolysaccharide-binding protein(LBP),but the underlying epigenetic mechanisms remain understudied.Herein,LBP^(-/-)rats with NAFLD were established and used to conduct integrative targetingactive enhancer histone H3 lysine 27 acetylation(H3K27ac)chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency.Notably,LBP^(-/-)reduced the inflammatory response but markedly aggravated high-fat diet(HFD)-induced NAFLD in rats,with pronounced alterations in the histone acetylome and regulatory transcriptome.In total,1128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type(WT)and LBP^(-/-)NAFLD rats.Based on integrative analysis,CCAAT/enhancer-binding proteinβ(C/EBPβ)was identified as a pivotal transcription factor(TF)and contributor to dysregulated histone acetylome H3K27ac,and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD.This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPβand functional gene SCD as potential regulators and therapeutic targets.
基金funded by project from National Research System (CONACYT),Mexico (to SIGC)
文摘Aging is a natural phenomenon characterized by a progressive decline in physiological integrity,leading to a deterioration of cognitive function and increasing the risk of suffering from chronic-degenerative diseases,including cardiovascular diseases,osteoporosis,cancer,diabetes,and neurodegeneration.Aging is considered the major risk factor for Parkinson’s and Alzheimer’s disease develops.Likewise,diabetes and insulin resistance constitute additional risk factors for developing neurodegenerative disorders.Currently,no treatment can effectively reverse these neurodegenerative pathologies.However,some antidiabetic drugs have opened the possibility of being used against neurodegenerative processes.In the previous framework,Vanadium species have demonstrated a notable antidiabetic effect.Our research group evaluated polyoxidovanadates such as decavanadate and metforminium-decavanadate with preventive and corrective activity on neurodegeneration in brain-specific areas from rats with metabolic syndrome.The results suggest that these polyoxidovanadates induce neuronal and cognitive restoration mechanisms.This review aims to describe the therapeutic potential of polyoxidovanadates as insulin-enhancer agents in the brain,constituting a therapeutic alternative for aging and neurodegenerative diseases.
基金National Key Research and Development Program,Grant/Award Number:2019YFA0903800,2021YFA0805701,2021YFA0805905 and 2022YFA1103603CAS Project for Young Scientists in Basic Research,Grant/Award Number:YSBR-012+2 种基金STI 2030-Major Project,Grant/Award Number:2023ZD0407503National Natural Science Foundation of China,Grant/Award Number:32071456 and 82241224Strategic Priority Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDA16030000。
文摘Background:Pig organ xenotransplantation is a potential solution for the severe organ shortage in clinic,while immunogenic genes need to be eliminated to improve the immune compatibility between humans and pigs.Current knockout strategies are mainly aimed at the genes causing hyperacute immune rejection(HAR)that occurs in the first few hours while adaptive immune reactions orchestrated by CD4 T cell thereafter also cause graft failure,in which process the MHCⅡmolecule plays critical roles.Methods:Thus,we generate a 4-gene(GGTA1,CMAH,β4GalNT2,and CIITA)knockout pig by CRISPR/Cas9 and somatic cell nuclear transfer to compromise HAR and CD4 T cell reactions simultaneously.Results:We successfully obtained 4KO piglets with deficiency in all alleles of genes,and at cellular and tissue levels.Additionally,the safety of our animals after gene editing was verified by using whole-genome sequencing and karyotyping.Piglets have survived for more than one year in the barrier,and also survived for more than 3 months in the conventional environment,suggesting that the piglets without MHCⅡcan be raised in the barrier and then gradually mated in the conventional environment.Conclusions:4KO piglets have lower immunogenicity,are safe in genomic level,and are easier to breed than the model with both MHCⅠandⅡdeletion.
基金supported by the National Natural Science Foundation of China(82271645)National Key Research and Development Program of China(2021YFC2700200 to F.S.)。
文摘Meiosis is a highly complex process significantly influenced by transcriptional regulation.However,studies on the mechanisms that govern transcriptomic changes during meiosis,especially in prophase I,are limited.Here,we performed single-cell ATAC-seq of human testis tissues and observed reprogramming during the transition from zygotene to pachytene spermatocytes.This event,conserved in mice,involved the deactivation of genes associated with meiosis after reprogramming and the activation of those related to spermatogenesis before their functional onset.Furthermore,we identified 282 transcriptional regulators(TRs)that underwent activation or deactivation subsequent to this process.Evidence suggested that physical contact signals from Sertoli cells may regulate these TRs in spermatocytes,while secreted ENHO signals may alter metabolic patterns in these cells.Our results further indicated that defective transcriptional reprogramming may be associated with non-obstructive azoospermia(NOA).This study revealed the importance of both physical contact and secreted signals between Sertoli cells and germ cells in meiotic progression.
文摘Timothy (Phleum pretense L.) pastures of 3 Total mixed ration (TMR) centers in Hokkaido were selected, the first cutting grasses were continuously collected from the same pastures on different harvest days over 4 years (2011-2014), and changes in the water soluble carbohydrates (WSC) content were analyzed to investigate the relationship with weather conditions. The harvest days in the 4-year period were June 17-22, June 24-26, June 27-30, and July 2-5, and grasses on these dates were designated as the harvest date groups. The weather data during the cutting period in each year were utilized. The WSC content tended to change yearly and it was significantly lower in the 4 groups (67.3 - 82.1 g/kg DM) in 2011 than in the groups (101.5 - 130.3 g/kg DM) in 2013 excluding the June 24-26 group (P < 0.05, P < 0.01). The WSC content tended to increase as the harvest date progressed in 2011-2013 and it significantly increased even though the harvest date was delayed only in 2013 (P < 0.01). It was suggested that differences in the WSC content among the years were related to the weather condition and dry matter yield of the grass.
基金supported by the National Natural Science Foundation of China,Nos. 31730031 and 32130060the National Major Project of Research and Development,No. 2017YFA0104700the Natural Science Foundation of Jiangsu Province,No. BK20202013 (all to XSG)。
文摘The key regulators and regeneration-associated genes involved in axonal regeneration of neurons after injury have not been clarified.In high-throughput sequencing,various factors influence the final sequencing results,including the number and size of cells,the depth of sequencing,and the method of cell separation.There is still a lack of research on the detailed molecular expression profile during the regeneration of dorsal root ganglion neuron axon.In this study,we performed lase r-capture microdissection coupled with RNA sequencing on dorsal root ganglion neurons at 0,3,6,and 12 hours and 1,3,and 7 days after sciatic nerve crush in rats.We identified three stages after dorsal root ganglion injury:early(3-12 hours),pre-regeneration(1 day),and regeneration(3-7 days).Gene expression patterns and related function enrichment res ults showed that one module of genes was highly related to axonal regeneration.We verified the up-regulation of activating transcription factor 3(Atf3),Kruppel like factor 6(Klf6),AT-rich inte raction domain 5A(Arid5α),CAMP responsive element modulator(Crem),and FOS like 1,AP-1 transcription factor Subunit(Fosl1) in dorsal root ganglion neurons after injury.Suppressing these transcription factors(Crem,Arid5o,Fosl1 and Klf6) reduced axonal regrowth in vitro.As the hub transcription factor,Atf3 showed higher expression and activity at the preregeneration and regeneration stages.G protein-coupled estrogen receptor 1(Gper1),inte rleukin 12a(Il12α),estrogen receptor 1(ESR1),and interleukin 6(IL6) may be upstream factors that trigger the activation of Atf3 during the repair of axon injury in the early stage.Our study presents the detailed molecular expression profile during axonal regeneration of dorsal root ganglion neurons after peripheral nerve injury.These findings may provide reference for the clinical screening of molecular targets for the treatment of peripheral nerve injury.
基金supported by the National Natural Science Foundation of China,No.31970968(to SYL)the Collegiate Natural Science Foundation of Jiangsu Province,No.16KJA310005(to SYL)+1 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions[PAPD]the Natural Science Foundation of Jiangsu Province,No.BK20200976(to XHW).
文摘Neurotrophic factors,particularly nerve growth factor,enhance neuronal regeneration.However,the in vivo applications of nerve growth factor are largely limited by its intrinsic disadvantages,such as its short biological half-life,its contribution to pain response,and its inability to cross the blood-brain barrier.Considering that let-7(human miRNA)targets and regulates nerve growth factor,and that let-7 is a core regulator in peripheral nerve regeneration,we evaluated the possibilities of let-7 application in nerve repair.In this study,anti-let-7a was identified as the most suitable let-7 family molecule by analyses of endogenous expression and regulatory relationship,and functional screening.Let-7a antagomir demonstrated biosafety based on the results of in vivo safety assessments and it entered into the main cell types of the sciatic nerve,including Schwann cells,fibroblasts and macrophages.Use of hydrogel effectively achieved controlled,localized,and sustained delivery of let-7a antagomir.Finally,let-7a antagomir was integrated into chitosan conduit to construct a chitosan-hydrogel scaffold tissue-engineered nerve graft,which promoted nerve regeneration and functional recovery in a rat model of sciatic nerve transection.Our study provides an experimental basis for potential in vivo application of let-7a.
基金Supported by the National Natural Science Foundation of China,No.81760808 and No.82260863Scientific and Technological Project of Education Department of Jiangxi Province,No.GJJ181582+1 种基金Jiangxi University of Chinese Medicine Science and Technology Innovation Team Development Program,No.CXTD22008Key Laboratory of Pharmacodynamics and Quality Evaluation on anti-Inflammatory Chinese Herbs,Jiangxi Administration of Traditional Chinese Medicine,No.202208.
文摘BACKGROUND Restoration of immune homeostasis by targeting the balance between memory T helper(mTh)cells and memory follicular T helper(mTfh)cells is a potential therapeutic strategy against ulcerative colitis(UC).Because of its anti-inflammatory and immunomodulatory properties,curcumin(Cur)is a promising drug for UC treatment.However,fewer studies have demonstrated whether Cur can modulate the mTh/mTfh subset balance in mice with colitis.AIM To explore the potential mechanism underlying Cur-mediated alleviation of colitis induced by dextran sulfate sodium(DSS)in mice by regulating the mTh and mTfh immune homeostasis.METHODS Balb/c mice were administered 3%and 2%DSS to establish the UC model and treated with Cur(200 mg/kg/d)by gavage on days 11-17.On the 18th d,all mice were anesthetized and euthanized,and the colonic length,colonic weight,and colonic weight index were evaluated.Histomorphological changes in the mouse colon were observed through hematoxylin-eosin staining.Levels of Th/mTh and Tfh/mTfh cell subsets in the spleen were detected through flow cytometry.Western blotting was performed to detect SOCS-1,SOCS-3,STAT3,p-STAT3,JAK1,p-JAK1,and NF-κB p65 protein expression levels in colon tissues.RESULTS Cur effectively mitigates DSS-induced colitis,facilitates the restoration of mouse weight and colonic length,and diminishes the colonic weight and colonic weight index.Simultaneously,it hinders ulcer development and inflammatory cell infiltration in the colonic mucous membrane.While the percentage of Th1,mTh1,Th7,mTh7,Th17,mTh17,Tfh1,mTfh1,Tfh7,mTfh7,Tfh17,and mTfh17 cells decreased after Cur treatment of the mice for 7 d,and the frequency of mTh10,Th10,mTfh10,and Tfh10 cells in the mouse spleen increased.Further studies revealed that Cur administration prominently decreased the SOCS-1,SOCS-3,STAT3,p-STAT3,JAK1,p-JAK1,and NF-κB p65 protein expression levels in the colon tissue.CONCLUSION Cur regulated the mTh/mTfh cell homeostasis to reduce DSS-induced colonic pathological damage,potentially by suppressing the JAK1/STAT3/SOCS signaling pathway.
基金Supported by the National Natural Science Foundation of China(No.31972811)the Special Fund for Basic Scientific Research of Central Public Research Institutes(No.2020T51)。
文摘Reproduction is subtlety regulated by the hypothalamic-pituitary-gonad(HPG)axis in vertebrates.Pituitary gland is the center of the HPG axis,while pituitary gonadotropins follicle stimulating hormone(FSH)and luteinizing hormone(LH)were identified the key elements of the HPG axis in teleost and mammal.Morphology,cell lines,and gonadotropins cell localization of female turbot and mouse pituitary were determined at mature stage to illustrate the anatomical difference and cell characteristics in this study.Results show that turbot pituitary is chicken heart-shaped,dorsoventral,located on the ventral surface of the diencephalon.The mouse pituitary is oval,located in the pituitary fossa of the sella turcica at the skull base.Two well-distinguished areas adenohypophysis(AH)and neurohypophysis(NH)in pituitary were identified in turbot and mouse.Turbot AH comprised the rostral pars distalis(RPD),proximal pars distalis(PPD),and pars intermedia(PI).NH was not pronounced and with finger-like protrusions into PPD.However,mouse AH only comprised the pars distalis(PD)and PI.NH distribution was semicircular.Three main types of cells(acidophilic,basophilic,and chromophobic cells)were distributed in the mouse PD region,whereas appeared in the turbot PPD,RPD,and PI.Moreover,the percentage of mouse chromophobic and basophilic cells was higher and lower than that of turbot,respectively.The diameter of the aforementioned three cells in the mouse was significantly higher than turbot.fshβ-and lhβ-immunoreactive signals were identified in turbot-distinct pituitary cells that primarily occupied the peripheral and central regions of AH.However,mouse fsh-and lh-immunoreactive cells were expressed in the same cells and present in the PD.These results demonstrate the significantly difference of pituitary morphology,cell lines and gonadotropins(fshβand lhβ)location in female turbot and mouse.These differences help for fully understand the evolution and endocrinological functions of pituitary.
基金the National Natural Science Foundation of China(U21A20376,82102871,81988101,81903184,81790633,and 81830054)the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-07E00065)+1 种基金the National Science Foundation of Shanghai(21XD1404600,21JC1406600,and 22140901000)the China Postdoctoral Science Foundation(2020M671007).
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China,No.2016D01C120(to JB)
文摘Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.
基金This research was supported by the Ministry of Science and Technology Grant (2001CB510106);Science and Technology Plan of Beijing Municipal Government (H020220050290);National Natural Science Foundation of China Awards for 0utstanding Young Scientists (30125022);for Creative Research Groups (30421004);Bill & Melinda Gates Foundation Grant (37871) to H Deng.
文摘The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid (RA) was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin (STZ)-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.
基金This research was supported by the Natural Science Foundation of Shaanxi (No. 2007C267)National Natural Science Foundation of China (No. 60601026)National 863 Project (No. 2006 AA0224C3)
文摘Objective To study the effect of electromagnetic pulse (EMP) exposure on the permeability of blood-testicle barrier (BTB) in mice. Methods Adult male BALB/c mice were exposed to EMP at 200 kV/m for 200 pulses with 2 seconds interval. The mice were injected with 2% Evans Blue solution through caudal vein at different time points after exposure, and the permeability of BTB was monitored using a fluorescence microscope. The testis sample for the transmission electron microscopy was prepared at 2 h after EMP exposure. The permeability of BTB in mice was observed by using Evans Blue tracer and lanthanum nitrate tracer. Results After exposure, cloudy Evans Blue was found in the testicle convoluted seminiferous tubule of mice. Lanthanum nitrate was observed not only between testicle spermatogonia near seminiferous tubule wall and sertoli cells, but also between sertoli cells and primary spermatocyte or secondary spermatocyte. In contrast, lanthanum nitrate in control group was only found in the testicle sertoli cells between seminiferous tubule and near seminifdrous tubule wall. Conclusion EMP exposure could increase the permeability of BTB in the mice.
文摘Litter size and birth weights are limited by uterine capacity, defined as the ability of the uterus to maintain the appropriate development of some number of conceptuses. Uterine capacity is the result of the combined effects of uterine, placental and embryo/fetal function. The number of living conceptuses that the uterus is capable of supporting is greater during early gestation compared to later gestation. Plots of log fetal weight versus log placental weight also indicate that fetal weights are less sensitive to reduced placental weight (and therefore reduced intrauterine space) in early gestation compared to late gestation. However, even in late gestation, mechanisms still exist that maintain fetal growth when the size of the placenta is reduced. One such mechanism is likely to be improved development of the folded placental-epithelial/maternal-epithelial bilayer. Fold depth, and therefore the maternal fetal interactive surface, increases as gestation advances and is greater in placenta from smal fetuses. On the fetal side of the placenta, the epithelial bilayer is embedded in stromal tissue. Glycosaminoglycans are major components of stroma, including hyaluronan and heparan sulfate. Hyaluronidases and heparanases are present within placental tissues, and likely play roles in modification of stromal components to facilitate fold development. Glycosaminoglycans are polymers of forms of glucose (glucosamine, glucuronic acid, iduronic acid) suggesting that glycosaminoglycan synthesis may compete with the glucose needs of the developing fetus. Pig conceptuses are fructogenic, such that a substantial portion of glucose transferred from mother to fetus is converted to fructose. Fructose is an intermediate product in the synthesis of glucosamine from glucose, and glucosamine is linked to regulation of trophoblast cell proliferation through regulation of mTOR. These findings suggest a link between glucose, fructose, glucosamine synthesis, GAG production, and placental morphogenesis, but the details of these interactions remain unclear. In addition, recent placental epithelial transcriptome analysis identified several glucose, amino acid, lipid, vitamin, mineral and hormone transporter mechanisms within the placenta. Further elucidation of mechanisms of placental morphogenesis and solute transport could provide clues to improving nutrient transport to the pig fetus, potentially increasing litter size and piglet birth weights.
文摘Lysozyme is a naturally occurring enzyme found in bodily secretions such as tears, saliva, and milk. It functions as an antimicrobial agent by cleaving the peptidoglycan component of bacterial cell walls, which leads to cell death. Antibiotics are also antimicrobials and have been fed at subtherapeutic levels to swine as growth promoters. These compounds benefit swine producers by minimizing production losses by increasing feed efficiency and decreasing susceptibility to bacterial infection and disease. This manuscript reviews the knowledge of the effects of lysozyme, as compared to traditional subtherapeutic antibiotics in swine feed, on pig performance and health. It is clear from decades of studies that antibiotic use in feeds increases pig performance, particularly in the nursery. Similarly, lysozyme, as a feed additive, increases growth and feed efficiency. While the mechanism by which antibiotics and lysozyme improve performance is not clearly understood, both of these feed additives improve gastrointestinal health, improve the metabolic profile, and alter the gastrointestinal bacteria ecology of swine. Therefore, lysozyme is a suitable alternative to growth-promoting subtherapeutic antibiotic use in swine feed.
基金This study was supported by the National Key Basic Research Program of China,No.2017YFA0104701(to XSG)the National Natural Science Foundation of China,No.31730031(to XSG),81870975(to SLZ)+1 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)(to XSG)the Natural Science Foundation of Jiangsu Province,No.BK20202013(to XSG).
文摘Recovery from injury to the peripheral nervous system is different from that of the central nervous system in that it can lead to gene reprogramming that can induce the expression of a series of regeneration-associated genes.This eventually leads to axonal regeneration of injured neurons.Although some regeneration-related genes have been identified,the regulatory network underlying axon regeneration remains largely unknown.To explore the regulator of axon regeneration,we performed RNA sequencing of lumbar L4 and L5 dorsal root ganglion(DRG)neurons at different time points(0,3,6,12 hours,1,3 and 7 days)after rat sciatic nerve crush.The isolation of neurons was carried out by laser capture microscopy combined with NeuN immunofluorescence staining.We found 1228 differentially expressed genes in the injured sciatic nerve tissue.The hub genes within these differentially expressed genes include Atf3,Jun,Myc,Ngf,Fgf2,Ezh2,Gfap and Il6.We verified that the expression of the enhancer of zeste homologue 2 gene(Ezh2)was up-regulated in DRG neurons after injury,and this up-regulation differed between large-and small-sized dorsal root ganglion neurons.To investigate whether the up-regulation of Ezh2 impacts axonal regeneration,we silenced Ezh2 with siRNA in cultured DRG neurons and found that the growth of the newborn axons was repressed.In our investigation into the regulatory network of Ezh2 by interpretive phenomenal analysis,we found some regulators of Ezh2(including Erk,Il6 and Hif1a)and targets(including Atf3,Cdkn1a and Smad1).Our findings suggest that Ezh2,as a nerve regeneration-related gene,participates in the repair of the injured DRG neurons,and knocking down the Ezh2 in vitro inhibits the axonal growth of DRG neurons.All the experimental procedures approved by the Administration Committee of Experimental Animals of Jiangsu Province of China(approval No.S20191201-201)on March 21,2019.
基金This research was supported by grants from the Ministry of Ed- ucation (705001), National Basic Research Program of China (973 Program 2009CB941200), National Natural Science Foundation of China (30830061 and 30421004), and a 111 project to H Deng. We thank Dr Tak Wah Mak (University of Alberta, Canada) for kindly providing the Ptern mice, Dr Guoqiang Gu (Vanderbilt University, USA) for kindly providing the plasmid of Pdxl-Cre, and Dr C Wright (Vanderbilt University, USA) for the PDX1 antibody. We thank the Model Animal Research Center of Nanjing University for B6 129-Gt(ROSA)26Sor tm/Sho/J mice and the Research Center for Proteome Analysis for proteomics analysis. We thank Dr Matt Stremlau, Dr Hui Zhang, Jun Cai, Han Qin, Jian Li, Yan Shi, Haisheng Zhou, and Fei Ye for their critical reading of the manu- script. We also thank Wei Jiang, Yushan Guo, Jie Yang, Chengyan Wang, Hui Zhang, and other colleagues in our laboratory for providing technical assistance and advice during the experiments.
文摘PTEN, a negative regulator of the phosphatidylinositol-3-kinase/AKT pathway, is an important modulator of insulin signaling. To determine the metabolic function of pancreatic Pten, we generated pancreas-specific Pten knockout (PPKO) mice. PPKO mice had enlarged pancreas and elevated proliferation of acinar cells. They also exhibited hypoglycemia, hypoinsulinemia, and altered amino metabolism. Notably, PPKO mice showed delayed onset of streptozotocin (STZ)-induced diabetes and sex-biased resistance to high-fat-diet (HFD)-induced diabetes. To investigate the mechanism for the resistance to HFD-induced hyperglycemia in PPKO mice, we evaluated AKT phosphorylation in major insulin-responsive tissues: the liver, muscle, and fat. We found that Pten loss in the pancreas causes the elevation of AKT signaling in the liver. The phosphorylation of AKT and its downstream substrate GSK3β was increased in the liver of PPKO mice, while PTEN level was decreased without detectable excision of Pten allele in the liver of PPKO mice. Proteomics analysis revealed dramatically decreased level of 78-kDa glucose-regulated protein (GRP78) in the liver of PPKO mice, which may also contribute to the lower blood glucose level of PPKO mice fed with HFD. Together, our findings reveal a novel response in the liver to pancreatic defect in metabolic regulation, adding a new dimension to understanding diabetes resistance.
基金the National Natural Science Foundation of China,No.30870876the Natural Science Foundation of Guangdong Province,No.815101700100005+2 种基金the Science and Technology Program of Guangdong Province,No.2005B60302004,2008B030301371,2009B030801368the Traditional Chinese Medicineand Combination of Traditional Chinese and Western Medicine Program of Guangzhou,No.2008A52the Medical and Health Scientific Research Program of Guangzhou,No.2009-YB-167
文摘In the present study,Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error counts,indicating a learning and memory disorder.After treatment with 30,60,90,120,or 200 mg/kg lithium chloride,the learning and memory abilities of the Fmr1 KO mice were significantly ameliorated,in particular,the 200 mg/kg lithium chloride treatment had the most significant effect.Western blot analysis showed that lithium chloride significantly enhanced the expression of phosphorylated glycogen synthase kinase 3 beta,an inactive form of glycogen synthase kinase 3 beta,in the cerebral cortex and hippocampus of the Fmr1 KO mice.These results indicated that lithium chloride improved learning and memory in the Fmr1 KO mice,possibly by inhibiting glycogen synthase kinase 3 beta activity.
文摘T cells are derived from progenitor thymocytes, of which only a minority receive the appropriate TCR signal, undergo positive selection and mature. Owing to the very short lifespan of thymocytes, the prerequisite for posi- tive selection is survival. TCR signal-induced Bcl-2 expression is believed to play a dominant role in the survival of positively selecting thymocytes, but how Bcl-2 is directly regulated is unknown. Here we report that the immediate early gene (IEG) c-Fos can stimulate the expression of Bcl-2, depending on a specific AP-l-binding site in the Bcl-2 promoter. In c-Fos transgenic (Fos-Tg) mice, c-Fos binds to this site and promotes the expression of Bcl-2. As a result, Fos-Tg thymocytes exhibited enhanced survival, and more mature single-positive (SP) thymocytes were generated, even on a unique TCR background. The TCR repertoire remained normal in Fos-Tg mice. Our results identified c-Fos as the mediator of the stimulatory effect of TCR signaling on Bcl-2 expression. Therefore, c-Fos, as an IEG, because of its early response ability, can quickly rescue the survival of short-lived thymocytes during positive selection. Our results provide novel insight into the mechanism regulating the survival of positively selecting thymocytes.