Islet beta cells(β-cells)produce insulin in response to high blood glucose levels,which is essential for preserving glucose homeostasis.Voltage-gated ion channels inβ-cells,including Na+,K+,and Ca2+channels,aid in t...Islet beta cells(β-cells)produce insulin in response to high blood glucose levels,which is essential for preserving glucose homeostasis.Voltage-gated ion channels inβ-cells,including Na+,K+,and Ca2+channels,aid in the release of insulin.The epithelial sodium channel alpha subunit(α-ENaC),a voltage-independent sodium ion channel,is also expressed in human pancreatic endocrine cells.However,there is no reported study on the function of ENaC in theβ-cells.In the current study,we found thatα-ENaC was expressed in human pancreatic glandule and pancreatic isletβ-cells.In the pancreas of db/db mice and high-fat diet-induced mice,and in mouse isletβ-cells(MIN6 cells)treated with palmitate,α-ENaC expression was increased.Whenα-ENaC was overexpressed in MIN6 cells,insulin content and glucose-induced insulin secretion were significantly reduced.On the other hand,palmitate injured isletβ-cells and suppressed insulin synthesis and secretion,but increasedα-ENaC expression in MIN6 cells.However,α-ENaC knockout(Scnn1a−/−)in MIN6 cells attenuatedβ-cell disorder induced by palmitate.Furthermore,α-ENaC regulated the ubiquitylation and degradation of sirtuin 2 inβ-cells.α-ENaC also modulatedβ-cell function in correlation with the inositol-requiring enzyme 1 alpha/X-box binding protein 1(IRE1α/XBP1)and protein kinase RNA-like endoplasmic reticulum kinase/C/EBP homologous protein(PERK/CHOP)endoplasmic reticulum stress pathways.These results suggest thatα-ENaC may play a novel role in insulin synthesis and secretion in theβ-cells,and the upregulation ofα-ENaC promotes isletβ-cell dysfunction.In conclusion,α-ENaC may be a key regulator involved in isletβ-cell damage and a potential therapeutic target for type 2 diabetes mellitus.展开更多
Objective:To examine the action of the effective component,4'-methylether-scutellarein,from Verbena officinalis L.(VOL)on the proliferation and apoptosis of human choriocarcinomaJAR cells.Methods:Cell proliferatio...Objective:To examine the action of the effective component,4'-methylether-scutellarein,from Verbena officinalis L.(VOL)on the proliferation and apoptosis of human choriocarcinomaJAR cells.Methods:Cell proliferation was measured by MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyl tetrasodium bromide,MTT]assay and the incorporation of tritiated thymidine(~3H-TdR).Apoptosis of cell was evaluated by flow cytometry(FCM)and the characteristic apoptoticDNA ladder by agarose gel electrophoresis,and the morphological changes of apoptotic JAR cellswere observed under fluorescence microscopy and electron microscopy(EM).Expressions of ap-optosis proteins,poly(ADP-ribose)polymerase(PARP)and caspase-3,-8,and -9 were deter-mined with Western blot.Results:The effective component from VOL inhibited the proliferation of JAR cells in a dose-and time-dependent manner.The treated cell cycle was arrested in S phase and an apoptotic peakwas found in S phase using FCM analysis.A typical DNA ladder appeared in the treatment groupwhen analyzed by agarose gel electrophoresis.Using fluorescence microscopy,the percentage ofapoptotic cell was 0.9%,6%,and 14% after treatments of 10,20,and 40 mg·L^(-1) of the effec-tive component,respectively,for 48 h.Typical apoptotic changes,such as condensed chromatinand presence of apoptotic bodies,were observed under EM.Treatment with effective componentfor 48 h and 72 h also induced protein expression of PARP and caspase-3,-8,and -9 as seen byWestern blot.Conclusions:The effective component from VOL inhibits cell proliferation and induces apop-tosis in human choriocarcinoma JAR cells.展开更多
Chronic high glucose(HG) plays a crucial role in the pathogenesis of diabetes-induced osteoporosis by inhibiting the differentiation and proliferation of osteoblasts. This study aims to examine the role of E26 transfo...Chronic high glucose(HG) plays a crucial role in the pathogenesis of diabetes-induced osteoporosis by inhibiting the differentiation and proliferation of osteoblasts. This study aims to examine the role of E26 transformation-specific 1(ETS1) in the inhibition of osteoblast differentiation and proliferation caused by chronic HG, as well as the underlying mechanism. Chronic HG treatment downregulated ETS1 expression and inhibited differentiation and proliferation of MC3 T3-E1 cells. Downregulation of ETS1 expression inhibited the differentiation and proliferation of MC3 T3-E1 cells under normal glucose conditions, and ETS1 overexpression attenuated the damage to cells exposed to chronic HG. In addition, ETS1 overexpression reversed the decrease in runt-related transcription factor 2(Runx2) expression in MC3 T3-E1 cells treated with chronic HG. Using chromatin immunoprecipitation(ChIP) and luciferase reporter assays, we confirmed that ETS1 directly bound to and increased the activity of the Runx2 promoter. In summary, our study suggested that ETS1 was involved in the inhibitory effect of chronic HG on osteogenic differentiation and proliferation and may be a potential therapeutic target for diabetes-induced osteoporosis.展开更多
Stroke is one of the leading causes of disability and death globally.It occurs when a major artery is occluded in the brain and leads to death of cells within the injured tissue.（＋）-Borneol,a simple bicyclic monote...Stroke is one of the leading causes of disability and death globally.It occurs when a major artery is occluded in the brain and leads to death of cells within the injured tissue.（＋）-Borneol,a simple bicyclic monoterpene extracted from traditional Chinese medicine,is widely used in various types of diseases.However,no study has proved the effects of（＋）-borneol on functional recovery from permanent ischemic stroke and the mechanism is still unknown.Here,we report that in the rat model of permanent cerebral ischemia,we found that（＋）-borneol（1.0 mg/kg） significantly ameliorated infarct size and neurological scores via reducing the expression of inducible nitric oxide synthase（iNOS）and tumor necrosis factor-alpha（TNF-α） in a dose dependent manner.Notably,（＋）-borneol showed long-term effects on the improvement of sensorimotor functions in the photothrombotic model of stroke,which decreased the number of foot faults in the grid-walking task and forelimb asymmetry scores in the cylinder task,at least in part through reducing loss of dendritic spines in the length,brunch number and density.These findings suggest that（＋）-borneol could serve as a therapeutic target for ischemic stroke.展开更多
The outbreak of COVID-19 caused by SARS-CoV-2 is spreading worldwide,with the pathogenesis mostly unclear.Both virus and host-derived microRNA(miRNA)play essential roles in the pathology of virus infection.This study ...The outbreak of COVID-19 caused by SARS-CoV-2 is spreading worldwide,with the pathogenesis mostly unclear.Both virus and host-derived microRNA(miRNA)play essential roles in the pathology of virus infection.This study aims to uncover the mechanism for SARS-CoV-2 pathogenicity from the perspective of miRNA.We scanned the SARS-CoV-2 genome for putative miRNA genes and miRNA targets and conducted in vivo experiments to validate the virus-encoded miRNAs and their regulatory role on the putative targets.One of such virus-encoded miRNAs,MR147-3p,was overexpressed that resulted in significantly decreased transcript levels of all of the predicted targets in human,i.e.,EXOC7,RAD9A,and TFE3 in the virus-infected cells.The analysis showed that the immune response and cytoskeleton organization are two of the most notable biological processes regulated by the infection-modulated miRNAs.Additionally,the genomic mutation of SARS-CoV-2 contributed to the changed miRNA repository and targets,suggesting a possible role of miRNAs in the attenuated phenotype of SARS-CoV-2 during its evolution.This study provided a comprehensive view of the miRNA-involved regulatory system during SARS-CoV-2 infection,indicating possible antiviral therapeutics against SARS-CoV-2 through intervening miRNA regulation.展开更多
Objective：Interleukin-1β（IL-1β）plays an important role in the development of type 1 and type 2 diabetes mellitus.Resveratrol,a polyphenol,is known to have a wide range of pharmacological properties in vitro.In th...Objective：Interleukin-1β（IL-1β）plays an important role in the development of type 1 and type 2 diabetes mellitus.Resveratrol,a polyphenol,is known to have a wide range of pharmacological properties in vitro.In this research,we examined the effects of resveratrol on IL-1β-inducedβ-cell dysfunction.Methods：We first evaluated the effect of resveratrol on nitric oxide（NO）formation in RINm5F cells stimulated with IL-1βusing the Griess method.Next,we performed transient transfection and reporter assays to measure the transcriptional activity of peroxisome proliferator-activated receptor-γ（PPAR-γ）.We also used Western blotting analysis to assess the effect of resveratrol on inducible nitric oxide synthase（iNOS）expression and nuclear factor-κB（NF-κB）translocation to the nuclei in cells treated with IL-1β.In addition,we assessed the transcriptional activity of NF-κB using an electrophoretic mobility shift assay（EMSA）.Finally,we evaluated the effect of resveratrol on IL-1β-induced inhibition of glucose-stimulated insulin secretion in freshly isolated rat pancreatic islets.Results：Resveratrol significantly suppressed IL-1β-induced NO production,a finding that correlated well with reduced levels of iNOS mRNA and protein.The molecular mechanism by which resveratrol inhibited iNOS gene expression appeared to involve increased PPAR-γactivity,which resulted in the inhibition of NF-κB activation.Further analysis showed that resveratrol could prevent IL-1β-induced inhibition of glucose-stimulated insulin secretion in rat islets.Conclusion：In this study,we demonstrated that resveratrol could protect against pancreaticβ-cell dysfunction caused by IL-1β.展开更多
Objective： We have previously found that mbr is a regulatory element of the bcl2 gene. The objective of this study is to isolate and identify the proteins binding to the 37 mbr in the 3 ＇ -end of the mbr. Methods： ...Objective： We have previously found that mbr is a regulatory element of the bcl2 gene. The objective of this study is to isolate and identify the proteins binding to the 37 mbr in the 3 ＇ -end of the mbr. Methods： Streptavidin magnetic particles were ligated to concatameric oligonucleotides of 37 mbr and incubated with the nuclear extracts of Jurkat cells. The DNA-binding proteins were eluted and then resolved by SDS-PAGE. After silver staining, the protein bands were excised and subjected to MALDI-TOF MS. Results： Several protein bands were detected after the isolation with magnetic particles, and Splicing factor, proline- and glutamine-rich（SFPQ）, Poly（ADP-ribose） polymerase I（PARP）, and promyelocytic leukemia protein（PML） were identified by MALDI-TOF MS. Conclusion： Several proteins were isolated and identified from the 37 mbr-protein complex. Results of this study establish a foundation for further study of the mechanisms by which mbr executes its regulatory function.展开更多
The abnormality of the p53 tumor suppressor is crucial in lung cancer development,because p53 regulates target gene promoters to combat cancer.Recent studies have shown extensive p53 binding to enhancer elements.Howev...The abnormality of the p53 tumor suppressor is crucial in lung cancer development,because p53 regulates target gene promoters to combat cancer.Recent studies have shown extensive p53 binding to enhancer elements.However,whether p53 exerts a tumor suppressor role by shaping the enhancer landscape remains poorly understood.In the current study,we employed several functional genomics approaches to assess the enhancer activity at p53 binding sites throughout the genome based on our established TP53 knockout(KO)human bronchial epithelial cells(BEAS-2B).A total of 943 active regular enhancers and 370 super-enhancers(SEs)disappeared upon the deletion of p53,indicating that p53 modulates the activity of hundreds of enhancer elements.We found that one p53-dependent SE,located on chromosome 9 and designated as KLF4-SE,regulated the expression of the Krüppel-like factor 4(KLF4)gene.Furthermore,the deletion of p53 significantly decreased the KLF4-SE enhancer activity and the KLF4 expression,but increased colony formation ability in the nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced cell transformation model.Subsequently,in TP53 KO cells,the overexpression of KLF4 partially reversed the increased clonogenic capacity caused by p53 deficiency.Consistently,KLF4 expression also decreased in lung cancer tissues and cell lines.It appeared that overexpression of KLF4 significantly suppressed the proliferation and migration of lung cancer cells.Collectively,our results suggest that the regulation of enhancer formation and activity by p53 is an integral component of the p53 tumor suppressor function.Therefore,our findings offer some novel insights into the regulation mechanism of p53 in lung oncogenesis and introduce a new strategy for screening therapeutic targets.展开更多
Objective:While the reduction of transient receptor potential channel subfamily M member 5(TRPM5)has been reported in islet cells from type 2 diabetic(T2D)mouse models,its role in lipotoxicity-induced pancreaticβ-cel...Objective:While the reduction of transient receptor potential channel subfamily M member 5(TRPM5)has been reported in islet cells from type 2 diabetic(T2D)mouse models,its role in lipotoxicity-induced pancreaticβ-cell dysfunction remains unclear.This study aims to study its role.Methods:Pancreas slices were prepared from mice subjected to a high-fat-diet(HFD)at different time points,and TRPM5 expression in the pancreaticβcells was examined using immunofluorescence staining.Glucose-stimulated insulin secretion(GSIS)defects caused by lipotoxicity were mimicked by saturated fatty acid palmitate(Palm).Primary mouse islets and mouse insulinoma MIN6 cells were treated with Palm,and the TRPM5 expression was detected using qRT-PCR and Western blotting.Palm-induced GSIS defects were measured following siRNA-based Trpm5 knockdown.The detrimental effects of Palm on primary mouse islets were also assessed after overexpressing Trpm5 via an adenovirus-derived Trpm5(Ad-Trpm5).Results:HFD feeding decreased the mRNA levels and protein expression of TRPM5 in mouse pancreatic islets.Palm reduced TRPM5 protein expression in a time-and dose-dependent manner in MIN6 cells.Palm also inhibited TRPM5 expression in primary mouse islets.Knockdown of Trpm5 inhibited insulin secretion upon high glucose stimulation but had little effect on insulin biosynthesis.Overexpression of Trpm5 reversed Palm-induced GSIS defects and the production of functional maturation molecules unique toβcells.Conclusion:Our findings suggest that lipotoxicity inhibits TRPM5 expression in pancreaticβcells both in vivo and in vitro and,in turn,drivesβ-cell dysfunction.展开更多
Erythropoietin-producing hepatocellular carcinoma A3(EphA3)is a member of the largest subfamily of tyrosine kinase receptors-Eph receptors.Previous studies have shown that EphA3 is associated with tissue development.R...Erythropoietin-producing hepatocellular carcinoma A3(EphA3)is a member of the largest subfamily of tyrosine kinase receptors-Eph receptors.Previous studies have shown that EphA3 is associated with tissue development.Recently,we have found that the expression of EphA3 is elevated in the hypothalamus of mice with diet-induced obesity(DIO).However,the role of EphA3 in hypothalamic-controlled energy metabolism remains unclear.In the current study,we demonstrated that the deletion of EphA3 in the hypothalamus by CRISPR/Cas9-mediated gene editing promotes obesity in male mice with high-fat diet feeding rather than those with normal chow diet feeding.Moreover,the deletion of hypothalamic EphA3 promotes high-fat DIO by increasing food intake and reducing energy expenditure.Knockdown of EphA3 leads to smaller intracellular vesicles in GT1-7 cells.The current study reveals that hypothalamic EphA3 plays important roles in promoting DIO.展开更多
Nonalcoholic fatty liver disease (NAFLD) is considered a major health epidemic with an estimated 32.4% worldwide prevalence. No drugs have yet been approved and therapeutic nodes remain a major unmet need. Long noncod...Nonalcoholic fatty liver disease (NAFLD) is considered a major health epidemic with an estimated 32.4% worldwide prevalence. No drugs have yet been approved and therapeutic nodes remain a major unmet need. Long noncoding RNAs are emerging as an important class of novel regulators influencing multiple biological processes and the pathogenesis of NAFLD. Herein, we described a novel long noncoding RNA, lnc_217, which was liver enriched and upregulated in high-fat diet-fed mice, and a genetic animal model of NAFLD. We found that liver specific knockdown of lnc_217 was resistant to high-fat diet-induced hepatic lipid accumulation and decreased serum lipid in mice. Mechanistically, we demonstrated that knockdown of lnc_217 not only decreased de novo lipogenesis by inhibiting sterol regulatory element binding protein-1c cleavage but also increased fatty acid β- oxidation through activation of peroxisome proliferator-activated receptor α and carnitine palmitoyltransferase-1α. Taken together, we conclude that lnc_217 may be a novel regulator of hepatic lipid metabolism and a potential therapeutic target for the treatment of hepatic steatosis and NAFLD-related metabolic disorders.展开更多
Hepatocellular carcinoma(HCC)is a highly heterogeneous malignancy and lacks effective treatment.Bulk-sequencing of different gene transcripts by comparing HCC tissues and adjacent normal tissues provides some clues fo...Hepatocellular carcinoma(HCC)is a highly heterogeneous malignancy and lacks effective treatment.Bulk-sequencing of different gene transcripts by comparing HCC tissues and adjacent normal tissues provides some clues for investigating the mechanisms or identifying potential targets for tumor progression.However,genes that are exclusively expressed in a subpopulation of HCC may not be enriched or detected through such a screening.In the current study,we performed a single cell-clone-based screening and identified galectin-14 as an essential molecule in the regulation of tumor growth.The aberrant expression of galectin-14 was significantly associated with a poor overall survival of liver cancer patients with database analysis.Knocking down galectin-14 inhibited the proliferation of tumor growth,whereas overexpressing galectin-14 promoted tumor growth in vivo.Non-targeted metabolomics analysis indicated that knocking down galectin-14 decreased glycometabolism;specifically that glycoside synthesis was significantly changed.Further study found that galectin-14 promoted the expression of cell surface heparan sulfate proteoglycans(HSPGs)that functioned as co-receptors,thereby increasing the responsiveness of HCC cells to growth factors,such as epidermal growth factor and transforming growth factor-alpha.In conclusion,the current study identifies a novel HCC-specific molecule galectin-14,which increases the expression of cell surface HSPGs and the uptake of growth factors to promote HCC cell proliferation.展开更多
Primary biliary cholangitis(PBC)is an autoimmune liver disease characterized by the destruction of intrahepatic small bile ducts and progressive cholestasis,eventually leading to liver cirrhosis and hepatic failure wi...Primary biliary cholangitis(PBC)is an autoimmune liver disease characterized by the destruction of intrahepatic small bile ducts and progressive cholestasis,eventually leading to liver cirrhosis and hepatic failure without appropriate treatment(Terziroli Beretta-Piccoli et al.,2019).展开更多
The present study aims to investigate the therapeutic effect and mechanism of glycyrrhizic acid(GA)in diabetic peripheral neuropathy(DPN).GA significantly mitigated nerve conduction velocity(NCV)deficit and morphologi...The present study aims to investigate the therapeutic effect and mechanism of glycyrrhizic acid(GA)in diabetic peripheral neuropathy(DPN).GA significantly mitigated nerve conduction velocity(NCV)deficit and morphological abnormality and reduced high-mobility group box-1(HMGB1)expression in the sciatic nerves of diabetic rats independent of blood glucose and body weight.Notably,GA alleviated the increase of HMGB1 and the decrease of cell viability in high glucose-stimulated RSC96 cells.Furthermore,GA obviously reduced the concentration of inflammatory cytokines in the sciatic nerves of diabetic rats and supernatants of high glucose-exposed RSC96 cells,then restored the decreased expression levels of nerve growth factor(NGF)and neuritin-1,and the increased expression levels of cleaved caspase-3 and neuron-specific enolase.Additionally,GA markedly inhibited receptor for advanced glycation end products(RAGE)expression,p38MAPK phosphorylation,and the nuclear translocation of NF-κBp65 in diabetic rats and high glucose-exposed RSC96 cells.The promotional effect of high glucose in RSC96 cells was diminished following Hmgb1 siRNA treatment.Our findings indicate that GA may exert neuroprotection on DPN by suppressing HMGB1,which lead to extenuation of inflammation response,balance of NGF,neuritin-1 and caspase-3,as well as inactivation of RAGE/p38MAPK/NF-κBp65 signaling pathway.展开更多
Phosphofructokinase-1（PFK-1）,a major regulatory glycolytic enzyme,has been implicated in the functions of astrocytes and neurons.Here,we report that PFK-1 negatively regulates neurogenesis from neural stem cells（N...Phosphofructokinase-1（PFK-1）,a major regulatory glycolytic enzyme,has been implicated in the functions of astrocytes and neurons.Here,we report that PFK-1 negatively regulates neurogenesis from neural stem cells（NSCs）by targeting pro-neural transcriptional factors.Using in vitro assays,we found that PFK-1 knockdown enhanced,and PFK-1 overexpression inhibited the neuronal differentiation of NSCs,which was consistent with the findings from NSCs subjected to 5 h of hypoxia.Meanwhile,the neurogenesis induced by PFK-1 knockdown was attributed to the increased proliferation of neural progenitors and the commitment of NSCs to the neuronal lineage.Similarly,in vivo knockdown of PFK-1 also increased neurogenesis in the dentate gyrus of the hippocampus.Finally,we demonstrated that the neurogenesis mediated by PFK-1 was likely achieved by targeting mammalian achaete-scute homologue-1（Mash 1）,neuronal differentiation factor（NeuroD）,and sex-determining region Y（SRY）-related HMG box 2（Sox2）.All together,our results reveal PFK-1 as an important regulator of neurogenesis.展开更多
Class II HDACs, such as HDAC4, are critical regulators of the immune response in various immune cells;however, its role in innate immunity remains largely unknown.Here, we report that the overexpression of HDAC4 suppr...Class II HDACs, such as HDAC4, are critical regulators of the immune response in various immune cells;however, its role in innate immunity remains largely unknown.Here, we report that the overexpression of HDAC4 suppresses the production of type I interferons triggered by pattern-recognition receptors (PRRs). HDAC4 repressed the translocation of transcription factor IRF3 to the nucleus, thereby decreasing IRF3-mediated IFN-β expression. In particular, we also determined that HDAC4 can be phosphorylated and simultaneously block the phosphorylation of IRF3 at Ser386 and Ser396 by TBK1 and IKKε, respectively, by interacting with the kinase domain of TBK1 and IKKε. Furthermore, IFN-β may stimulate the expression of HDAC4. Our findings suggest that HDAC4 acts as a regulator of PRR signaling and is a novel mechanism of negative feedback regulation for preventing an overreactive innate immune response.展开更多
BCL2 is a key regulator of apoptosis.Our previous work has demonstrated that special AT-rich sequence-binding protein 1 （SATB1） is positively correlated with BCL2 expression.In the present study,we report a new SATB...BCL2 is a key regulator of apoptosis.Our previous work has demonstrated that special AT-rich sequence-binding protein 1 （SATB1） is positively correlated with BCL2 expression.In the present study,we report a new SATB1 binding site located between P1 and P2 promoters of the BCL2 gene.The candidate SATB1 binding sequence predicted by bioinformatic analysis was investigated in vitro and in vivo by electrophoretic gel mobility shift assays （EMSA） and chromatin immunoprecipitation （ChIP）.One 25-bp sequence,named SB1,was confirmed to be SATB1 binding site.The regulatory function of SB1 and its relevance to SATB1 were further examed with dual-luciferase reporter assay system in Jurkat cells.We found that SB1 could negatively regulate reporter gene activity.Mutation of SATB1 binding site further repressed the activity.Knockdown of SATB1 also enhanced this negative effect of SB1.Our data indicate that the SB1 sequence possesses negative transcriptional regulatory function and this function can be antagonized by SATB1.展开更多
Abnormal expression of long interspersed element-1(LINE-1)has been implicated in drug resistance,while our previous study showed that chemotherapy drug paclitaxel(PTX)increased LINE-1 level with unknown mechanism.Bioi...Abnormal expression of long interspersed element-1(LINE-1)has been implicated in drug resistance,while our previous study showed that chemotherapy drug paclitaxel(PTX)increased LINE-1 level with unknown mechanism.Bioinformatics analysis suggested the regulation of LINE-1 mRNA by drug-induced stress granules(SGs).This study aimed to explore whether and how SGs are involved in drug-induced LINE-1 increase and thereby promotes drug resistance of triple negative breast cancer(TNBC)cells.We demonstrated that SGs increased LINE-1 expression by recruiting and stabilizing LINE-1 mRNA under drug stress,thereby adapting TNBC cells to chemotherapy drugs.Moreover,LINE-1 inhibitor efavirenz(EFV)could inhibit drug-induced SG to destabilize LINE-1.Our study provides the first evidence of the regulation of LINE-1 by SGs that could be an important survival mechanism for cancer cells exposed to chemotherapy drugs.The findings provide a useful clue for developing new chemotherapeutic strategies against TNBCs.展开更多
Objective:The ataxia telangiectasia mutated(ATM)gene is a master regulator in cellular DNA damage response.The dysregulation of ATM expression is frequent in breast cancer,and is known to be involved in the carcinogen...Objective:The ataxia telangiectasia mutated(ATM)gene is a master regulator in cellular DNA damage response.The dysregulation of ATM expression is frequent in breast cancer,and is known to be involved in the carcinogenesis and prognosis of cancer.However,the underlying mechanism remains unclear.The bioinformatic analysis predicted a potential antisense transcript ATM-antisense(AS)from the opposite strand of the ATM gene.The purpose of this study was to identify ATM-AS and investigate the possible effect of ATM-AS on the ATM gene regulation.Methods:Single strand-specific RT-PCR was performed to verify the predicted antisense transcript ATM-AS within the ATM gene locus.qRT-PCR and Western blotting were used to detect the expression levels of ATM-AS and ATM in normal and breast cancer cell lines as well as in tissue samples.Luciferase reporter gene assays,biological mass spectrometry,ChIP-qPCR and RIP were used to explore the function of ATM-AS in regulating the ATM expression.Immunofluorescence and host-cell reactivation(HCR)assay were performed to evaluate the biological significance of ATM-AS in ATM-mediated DNA damage repair.Breast cancer tissue samples were used for evaluating the correlation of the ATM-AS level with the ATM expression as well as prognosis of the patients.Results:The ATM-AS significantly upregulated the ATM gene activity by recruiting KAT5 histone acetyltransferase to the gene promoter.The reduced ATM-AS level led to the abnormal downregulation of ATM expression,and impaired the ATM-mediated DNA damage repair in normal breast cells in vitro.The ATM-AS level was positively correlated with the ATM expression in the examined breast cancer tissue samples,and the patient prognosis.Conclusion:The present study demonstrated that ATM-AS,an antisense transcript located within the ATM gene body,is an essential positive regulator of ATM expression,and functions by mediating the binding of KAT5 to the ATM promoter.These findings uncover the novel mechanism underlying the dysregulation of the ATM gene in breast cancer,and enrich our understanding of how an antisense transcript regulates its host gene.展开更多
Impairment of glucose(Glu)uptake and storage by skeletal muscle is a prime risk factor for the development of metabolic diseases.Heterogeneous nuclear ribonucleoprotein A1(hnRNP Al)is a highly abundant RNA-binding pro...Impairment of glucose(Glu)uptake and storage by skeletal muscle is a prime risk factor for the development of metabolic diseases.Heterogeneous nuclear ribonucleoprotein A1(hnRNP Al)is a highly abundant RNA-binding protein that has been implicated in diverse cellular functions.The aim of this study was to investigate the function of hnRNP A1 on muscle tissue insulin sensitivity and systemic Glu homeostasis.Our results showed that conditional deletion of hnRNP Al in the muscle gave rise to a severe insulin resistance phenotype in mice fed a high-fat diet(HFD).Conditional knockout mice fed a HFD showed exacerbated obesity,insulin resistance,and hepatic steatosis.In vitro interference of hnRNP Al in C2C12 myotubes impaired insulin signal transduction and inhibited Glu uptake,whereas hnRNP Al overexpression in C2C12 myotubes protected against insulin resistance induced by supraphysiological concentrations of insulin.The expression and stability of glycogen synthase(gysl)mRNA were also decreased in the absence of hnRNP A l.Mechanistically,hnRNP Al interacted with gys l and stabilized its mRNA,thereby promoting glycogen synthesis and maintaining the insulin sensitivity in muscle tissue.Taken together,our findings are the first to show that reduced expression of hnRNP Al in skeletal muscle affects the metabolic properties and systemic insulin sensitivity by inhibiting glycogen synthesis.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.81870467 and 82270717 to XL,and 81970673 to FC)China Postdoctoral Science Foundation(Grant No.2023M731630 to XZhang)Postgraduate Research and Practice Innovation Program of Jiangsu Province(Grant No.KYCX21_1588 to XZhou).
文摘Islet beta cells(β-cells)produce insulin in response to high blood glucose levels,which is essential for preserving glucose homeostasis.Voltage-gated ion channels inβ-cells,including Na+,K+,and Ca2+channels,aid in the release of insulin.The epithelial sodium channel alpha subunit(α-ENaC),a voltage-independent sodium ion channel,is also expressed in human pancreatic endocrine cells.However,there is no reported study on the function of ENaC in theβ-cells.In the current study,we found thatα-ENaC was expressed in human pancreatic glandule and pancreatic isletβ-cells.In the pancreas of db/db mice and high-fat diet-induced mice,and in mouse isletβ-cells(MIN6 cells)treated with palmitate,α-ENaC expression was increased.Whenα-ENaC was overexpressed in MIN6 cells,insulin content and glucose-induced insulin secretion were significantly reduced.On the other hand,palmitate injured isletβ-cells and suppressed insulin synthesis and secretion,but increasedα-ENaC expression in MIN6 cells.However,α-ENaC knockout(Scnn1a−/−)in MIN6 cells attenuatedβ-cell disorder induced by palmitate.Furthermore,α-ENaC regulated the ubiquitylation and degradation of sirtuin 2 inβ-cells.α-ENaC also modulatedβ-cell function in correlation with the inositol-requiring enzyme 1 alpha/X-box binding protein 1(IRE1α/XBP1)and protein kinase RNA-like endoplasmic reticulum kinase/C/EBP homologous protein(PERK/CHOP)endoplasmic reticulum stress pathways.These results suggest thatα-ENaC may play a novel role in insulin synthesis and secretion in theβ-cells,and the upregulation ofα-ENaC promotes isletβ-cell dysfunction.In conclusion,α-ENaC may be a key regulator involved in isletβ-cell damage and a potential therapeutic target for type 2 diabetes mellitus.
文摘Objective:To examine the action of the effective component,4'-methylether-scutellarein,from Verbena officinalis L.(VOL)on the proliferation and apoptosis of human choriocarcinomaJAR cells.Methods:Cell proliferation was measured by MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyl tetrasodium bromide,MTT]assay and the incorporation of tritiated thymidine(~3H-TdR).Apoptosis of cell was evaluated by flow cytometry(FCM)and the characteristic apoptoticDNA ladder by agarose gel electrophoresis,and the morphological changes of apoptotic JAR cellswere observed under fluorescence microscopy and electron microscopy(EM).Expressions of ap-optosis proteins,poly(ADP-ribose)polymerase(PARP)and caspase-3,-8,and -9 were deter-mined with Western blot.Results:The effective component from VOL inhibited the proliferation of JAR cells in a dose-and time-dependent manner.The treated cell cycle was arrested in S phase and an apoptotic peakwas found in S phase using FCM analysis.A typical DNA ladder appeared in the treatment groupwhen analyzed by agarose gel electrophoresis.Using fluorescence microscopy,the percentage ofapoptotic cell was 0.9%,6%,and 14% after treatments of 10,20,and 40 mg·L^(-1) of the effec-tive component,respectively,for 48 h.Typical apoptotic changes,such as condensed chromatinand presence of apoptotic bodies,were observed under EM.Treatment with effective componentfor 48 h and 72 h also induced protein expression of PARP and caspase-3,-8,and -9 as seen byWestern blot.Conclusions:The effective component from VOL inhibits cell proliferation and induces apop-tosis in human choriocarcinoma JAR cells.
基金supported by 2021 Nantong City Basic Research and People's Livelihood Science and Technology Plan Guiding Project (JCZ21133)。
文摘Chronic high glucose(HG) plays a crucial role in the pathogenesis of diabetes-induced osteoporosis by inhibiting the differentiation and proliferation of osteoblasts. This study aims to examine the role of E26 transformation-specific 1(ETS1) in the inhibition of osteoblast differentiation and proliferation caused by chronic HG, as well as the underlying mechanism. Chronic HG treatment downregulated ETS1 expression and inhibited differentiation and proliferation of MC3 T3-E1 cells. Downregulation of ETS1 expression inhibited the differentiation and proliferation of MC3 T3-E1 cells under normal glucose conditions, and ETS1 overexpression attenuated the damage to cells exposed to chronic HG. In addition, ETS1 overexpression reversed the decrease in runt-related transcription factor 2(Runx2) expression in MC3 T3-E1 cells treated with chronic HG. Using chromatin immunoprecipitation(ChIP) and luciferase reporter assays, we confirmed that ETS1 directly bound to and increased the activity of the Runx2 promoter. In summary, our study suggested that ETS1 was involved in the inhibitory effect of chronic HG on osteogenic differentiation and proliferation and may be a potential therapeutic target for diabetes-induced osteoporosis.
基金supported by grants from National Natural Science Foundation of China(91232304, 31530091,81571188 and 81222016)the Natural Science Foundation of Jiangsu Province(BK2011029)Distinguished Young Scientists Fund(BK20130040)
文摘Stroke is one of the leading causes of disability and death globally.It occurs when a major artery is occluded in the brain and leads to death of cells within the injured tissue.（＋）-Borneol,a simple bicyclic monoterpene extracted from traditional Chinese medicine,is widely used in various types of diseases.However,no study has proved the effects of（＋）-borneol on functional recovery from permanent ischemic stroke and the mechanism is still unknown.Here,we report that in the rat model of permanent cerebral ischemia,we found that（＋）-borneol（1.0 mg/kg） significantly ameliorated infarct size and neurological scores via reducing the expression of inducible nitric oxide synthase（iNOS）and tumor necrosis factor-alpha（TNF-α） in a dose dependent manner.Notably,（＋）-borneol showed long-term effects on the improvement of sensorimotor functions in the photothrombotic model of stroke,which decreased the number of foot faults in the grid-walking task and forelimb asymmetry scores in the cylinder task,at least in part through reducing loss of dendritic spines in the length,brunch number and density.These findings suggest that（＋）-borneol could serve as a therapeutic target for ischemic stroke.
基金This work was supported by National Natural Science Foundation of China(NSFC)grant No.81671983 and 81871628 to X.L.,NSFC grant No.81703306China Postdoctoral Science Foundation(2017M611867)+1 种基金Postdoctoral Science Foundation of Jiangsu Province(1701119C)to Z.L.,NSFC grant No.81902027Natural Science Foundation of Jiangsu Province to J.W.(BK20171045).
文摘The outbreak of COVID-19 caused by SARS-CoV-2 is spreading worldwide,with the pathogenesis mostly unclear.Both virus and host-derived microRNA(miRNA)play essential roles in the pathology of virus infection.This study aims to uncover the mechanism for SARS-CoV-2 pathogenicity from the perspective of miRNA.We scanned the SARS-CoV-2 genome for putative miRNA genes and miRNA targets and conducted in vivo experiments to validate the virus-encoded miRNAs and their regulatory role on the putative targets.One of such virus-encoded miRNAs,MR147-3p,was overexpressed that resulted in significantly decreased transcript levels of all of the predicted targets in human,i.e.,EXOC7,RAD9A,and TFE3 in the virus-infected cells.The analysis showed that the immune response and cytoskeleton organization are two of the most notable biological processes regulated by the infection-modulated miRNAs.Additionally,the genomic mutation of SARS-CoV-2 contributed to the changed miRNA repository and targets,suggesting a possible role of miRNAs in the attenuated phenotype of SARS-CoV-2 during its evolution.This study provided a comprehensive view of the miRNA-involved regulatory system during SARS-CoV-2 infection,indicating possible antiviral therapeutics against SARS-CoV-2 through intervening miRNA regulation.
基金supported by grants from the National Natural Science Foundation of China(No.30370676 and No.30771041)the Special Funds for Major State Basic Research Program of China(973Program,No.2006CB503908)
文摘Objective：Interleukin-1β（IL-1β）plays an important role in the development of type 1 and type 2 diabetes mellitus.Resveratrol,a polyphenol,is known to have a wide range of pharmacological properties in vitro.In this research,we examined the effects of resveratrol on IL-1β-inducedβ-cell dysfunction.Methods：We first evaluated the effect of resveratrol on nitric oxide（NO）formation in RINm5F cells stimulated with IL-1βusing the Griess method.Next,we performed transient transfection and reporter assays to measure the transcriptional activity of peroxisome proliferator-activated receptor-γ（PPAR-γ）.We also used Western blotting analysis to assess the effect of resveratrol on inducible nitric oxide synthase（iNOS）expression and nuclear factor-κB（NF-κB）translocation to the nuclei in cells treated with IL-1β.In addition,we assessed the transcriptional activity of NF-κB using an electrophoretic mobility shift assay（EMSA）.Finally,we evaluated the effect of resveratrol on IL-1β-induced inhibition of glucose-stimulated insulin secretion in freshly isolated rat pancreatic islets.Results：Resveratrol significantly suppressed IL-1β-induced NO production,a finding that correlated well with reduced levels of iNOS mRNA and protein.The molecular mechanism by which resveratrol inhibited iNOS gene expression appeared to involve increased PPAR-γactivity,which resulted in the inhibition of NF-κB activation.Further analysis showed that resveratrol could prevent IL-1β-induced inhibition of glucose-stimulated insulin secretion in rat islets.Conclusion：In this study,we demonstrated that resveratrol could protect against pancreaticβ-cell dysfunction caused by IL-1β.
基金supported by grants from the National Natural Science Foundation of China(30500585)the Natural Science Foundation of Jiangsu Province(BK2008450)
文摘Objective： We have previously found that mbr is a regulatory element of the bcl2 gene. The objective of this study is to isolate and identify the proteins binding to the 37 mbr in the 3 ＇ -end of the mbr. Methods： Streptavidin magnetic particles were ligated to concatameric oligonucleotides of 37 mbr and incubated with the nuclear extracts of Jurkat cells. The DNA-binding proteins were eluted and then resolved by SDS-PAGE. After silver staining, the protein bands were excised and subjected to MALDI-TOF MS. Results： Several protein bands were detected after the isolation with magnetic particles, and Splicing factor, proline- and glutamine-rich（SFPQ）, Poly（ADP-ribose） polymerase I（PARP）, and promyelocytic leukemia protein（PML） were identified by MALDI-TOF MS. Conclusion： Several proteins were isolated and identified from the 37 mbr-protein complex. Results of this study establish a foundation for further study of the mechanisms by which mbr executes its regulatory function.
基金the National Natural Science Foundation of China(Grant No.82072580).
文摘The abnormality of the p53 tumor suppressor is crucial in lung cancer development,because p53 regulates target gene promoters to combat cancer.Recent studies have shown extensive p53 binding to enhancer elements.However,whether p53 exerts a tumor suppressor role by shaping the enhancer landscape remains poorly understood.In the current study,we employed several functional genomics approaches to assess the enhancer activity at p53 binding sites throughout the genome based on our established TP53 knockout(KO)human bronchial epithelial cells(BEAS-2B).A total of 943 active regular enhancers and 370 super-enhancers(SEs)disappeared upon the deletion of p53,indicating that p53 modulates the activity of hundreds of enhancer elements.We found that one p53-dependent SE,located on chromosome 9 and designated as KLF4-SE,regulated the expression of the Krüppel-like factor 4(KLF4)gene.Furthermore,the deletion of p53 significantly decreased the KLF4-SE enhancer activity and the KLF4 expression,but increased colony formation ability in the nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced cell transformation model.Subsequently,in TP53 KO cells,the overexpression of KLF4 partially reversed the increased clonogenic capacity caused by p53 deficiency.Consistently,KLF4 expression also decreased in lung cancer tissues and cell lines.It appeared that overexpression of KLF4 significantly suppressed the proliferation and migration of lung cancer cells.Collectively,our results suggest that the regulation of enhancer formation and activity by p53 is an integral component of the p53 tumor suppressor function.Therefore,our findings offer some novel insights into the regulation mechanism of p53 in lung oncogenesis and introduce a new strategy for screening therapeutic targets.
基金supported by grants from the National Natural Science Foundation of China(No.81830024,No.82270844 and No.82070843).
文摘Objective:While the reduction of transient receptor potential channel subfamily M member 5(TRPM5)has been reported in islet cells from type 2 diabetic(T2D)mouse models,its role in lipotoxicity-induced pancreaticβ-cell dysfunction remains unclear.This study aims to study its role.Methods:Pancreas slices were prepared from mice subjected to a high-fat-diet(HFD)at different time points,and TRPM5 expression in the pancreaticβcells was examined using immunofluorescence staining.Glucose-stimulated insulin secretion(GSIS)defects caused by lipotoxicity were mimicked by saturated fatty acid palmitate(Palm).Primary mouse islets and mouse insulinoma MIN6 cells were treated with Palm,and the TRPM5 expression was detected using qRT-PCR and Western blotting.Palm-induced GSIS defects were measured following siRNA-based Trpm5 knockdown.The detrimental effects of Palm on primary mouse islets were also assessed after overexpressing Trpm5 via an adenovirus-derived Trpm5(Ad-Trpm5).Results:HFD feeding decreased the mRNA levels and protein expression of TRPM5 in mouse pancreatic islets.Palm reduced TRPM5 protein expression in a time-and dose-dependent manner in MIN6 cells.Palm also inhibited TRPM5 expression in primary mouse islets.Knockdown of Trpm5 inhibited insulin secretion upon high glucose stimulation but had little effect on insulin biosynthesis.Overexpression of Trpm5 reversed Palm-induced GSIS defects and the production of functional maturation molecules unique toβcells.Conclusion:Our findings suggest that lipotoxicity inhibits TRPM5 expression in pancreaticβcells both in vivo and in vitro and,in turn,drivesβ-cell dysfunction.
基金supported by the National Natural Science Foundation of China (Grants No.82070872,92049118,and 81570774)the Jiangsu Province's Innovation Personal as well as Innovative and Entrepreneurial Team of Jiangsu Province (Grant No.JSSCTD2021)+1 种基金the National Key Research and Development Program of China (Grant No.2018YFC1003504)the Junior Thousand Talents Program of China,the NJMU startup fund.
文摘Erythropoietin-producing hepatocellular carcinoma A3(EphA3)is a member of the largest subfamily of tyrosine kinase receptors-Eph receptors.Previous studies have shown that EphA3 is associated with tissue development.Recently,we have found that the expression of EphA3 is elevated in the hypothalamus of mice with diet-induced obesity(DIO).However,the role of EphA3 in hypothalamic-controlled energy metabolism remains unclear.In the current study,we demonstrated that the deletion of EphA3 in the hypothalamus by CRISPR/Cas9-mediated gene editing promotes obesity in male mice with high-fat diet feeding rather than those with normal chow diet feeding.Moreover,the deletion of hypothalamic EphA3 promotes high-fat DIO by increasing food intake and reducing energy expenditure.Knockdown of EphA3 leads to smaller intracellular vesicles in GT1-7 cells.The current study reveals that hypothalamic EphA3 plays important roles in promoting DIO.
基金This work was supported by grants from the National Natural Science Foundation of China(Grant Nos.32130050,32201064,and 82170838)the Natural Science Research Project of Universities in Jiangsu Province(Grant No.21KJB180003).
文摘Nonalcoholic fatty liver disease (NAFLD) is considered a major health epidemic with an estimated 32.4% worldwide prevalence. No drugs have yet been approved and therapeutic nodes remain a major unmet need. Long noncoding RNAs are emerging as an important class of novel regulators influencing multiple biological processes and the pathogenesis of NAFLD. Herein, we described a novel long noncoding RNA, lnc_217, which was liver enriched and upregulated in high-fat diet-fed mice, and a genetic animal model of NAFLD. We found that liver specific knockdown of lnc_217 was resistant to high-fat diet-induced hepatic lipid accumulation and decreased serum lipid in mice. Mechanistically, we demonstrated that knockdown of lnc_217 not only decreased de novo lipogenesis by inhibiting sterol regulatory element binding protein-1c cleavage but also increased fatty acid β- oxidation through activation of peroxisome proliferator-activated receptor α and carnitine palmitoyltransferase-1α. Taken together, we conclude that lnc_217 may be a novel regulator of hepatic lipid metabolism and a potential therapeutic target for the treatment of hepatic steatosis and NAFLD-related metabolic disorders.
基金The current study was supported by the National Natural Science Foundation of China(Grant Nos 81972284 and 82273239)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.22KJB310001)Nanjing Medical University Science and Technology Development Foundation(Grant Nos.NMUB-20220050 and NMUB20210006).
文摘Hepatocellular carcinoma(HCC)is a highly heterogeneous malignancy and lacks effective treatment.Bulk-sequencing of different gene transcripts by comparing HCC tissues and adjacent normal tissues provides some clues for investigating the mechanisms or identifying potential targets for tumor progression.However,genes that are exclusively expressed in a subpopulation of HCC may not be enriched or detected through such a screening.In the current study,we performed a single cell-clone-based screening and identified galectin-14 as an essential molecule in the regulation of tumor growth.The aberrant expression of galectin-14 was significantly associated with a poor overall survival of liver cancer patients with database analysis.Knocking down galectin-14 inhibited the proliferation of tumor growth,whereas overexpressing galectin-14 promoted tumor growth in vivo.Non-targeted metabolomics analysis indicated that knocking down galectin-14 decreased glycometabolism;specifically that glycoside synthesis was significantly changed.Further study found that galectin-14 promoted the expression of cell surface heparan sulfate proteoglycans(HSPGs)that functioned as co-receptors,thereby increasing the responsiveness of HCC cells to growth factors,such as epidermal growth factor and transforming growth factor-alpha.In conclusion,the current study identifies a novel HCC-specific molecule galectin-14,which increases the expression of cell surface HSPGs and the uptake of growth factors to promote HCC cell proliferation.
基金supported by grants from the National Natural Science Foundation of China,China(Nos.81870397,82000534,and 82073156)Shenzhen Kangzhe Pharmaceutical Co.Ltd,China(URC-126/PBC)+1 种基金The Fifth Suzhou Health Talent Project(GSWS201903)The Suzhou Radiotherapy Clinical Medical Center Project,Suzhou,Jiangsu,China(Szlcyxzx202103).
文摘Primary biliary cholangitis(PBC)is an autoimmune liver disease characterized by the destruction of intrahepatic small bile ducts and progressive cholestasis,eventually leading to liver cirrhosis and hepatic failure without appropriate treatment(Terziroli Beretta-Piccoli et al.,2019).
基金supported by the National Natural Science Foundation of China (Grant No. 81700723)Research Project of Jiangsu 333 Engineering (Grant No. BRA2016232)Research Project of Jiangsu Provincial Commission of Health and Family Planning (Grant No. F201549/H201667)
文摘The present study aims to investigate the therapeutic effect and mechanism of glycyrrhizic acid(GA)in diabetic peripheral neuropathy(DPN).GA significantly mitigated nerve conduction velocity(NCV)deficit and morphological abnormality and reduced high-mobility group box-1(HMGB1)expression in the sciatic nerves of diabetic rats independent of blood glucose and body weight.Notably,GA alleviated the increase of HMGB1 and the decrease of cell viability in high glucose-stimulated RSC96 cells.Furthermore,GA obviously reduced the concentration of inflammatory cytokines in the sciatic nerves of diabetic rats and supernatants of high glucose-exposed RSC96 cells,then restored the decreased expression levels of nerve growth factor(NGF)and neuritin-1,and the increased expression levels of cleaved caspase-3 and neuron-specific enolase.Additionally,GA markedly inhibited receptor for advanced glycation end products(RAGE)expression,p38MAPK phosphorylation,and the nuclear translocation of NF-κBp65 in diabetic rats and high glucose-exposed RSC96 cells.The promotional effect of high glucose in RSC96 cells was diminished following Hmgb1 siRNA treatment.Our findings indicate that GA may exert neuroprotection on DPN by suppressing HMGB1,which lead to extenuation of inflammation response,balance of NGF,neuritin-1 and caspase-3,as well as inactivation of RAGE/p38MAPK/NF-κBp65 signaling pathway.
基金supported by grants from the National Natural Science Foundation of China(91232304,31530091,and 81571188)the National Basic Research Development Program(973 Program)of China(2011CB504404)+1 种基金the Natural Science Foundation of Jiangsu Province,China(BK2011029 and BK20130040)the Collaborative Innovation Center For Cardiovascular Disease Translational Medicine
文摘Phosphofructokinase-1（PFK-1）,a major regulatory glycolytic enzyme,has been implicated in the functions of astrocytes and neurons.Here,we report that PFK-1 negatively regulates neurogenesis from neural stem cells（NSCs）by targeting pro-neural transcriptional factors.Using in vitro assays,we found that PFK-1 knockdown enhanced,and PFK-1 overexpression inhibited the neuronal differentiation of NSCs,which was consistent with the findings from NSCs subjected to 5 h of hypoxia.Meanwhile,the neurogenesis induced by PFK-1 knockdown was attributed to the increased proliferation of neural progenitors and the commitment of NSCs to the neuronal lineage.Similarly,in vivo knockdown of PFK-1 also increased neurogenesis in the dentate gyrus of the hippocampus.Finally,we demonstrated that the neurogenesis mediated by PFK-1 was likely achieved by targeting mammalian achaete-scute homologue-1（Mash 1）,neuronal differentiation factor（NeuroD）,and sex-determining region Y（SRY）-related HMG box 2（Sox2）.All together,our results reveal PFK-1 as an important regulator of neurogenesis.
文摘Class II HDACs, such as HDAC4, are critical regulators of the immune response in various immune cells;however, its role in innate immunity remains largely unknown.Here, we report that the overexpression of HDAC4 suppresses the production of type I interferons triggered by pattern-recognition receptors (PRRs). HDAC4 repressed the translocation of transcription factor IRF3 to the nucleus, thereby decreasing IRF3-mediated IFN-β expression. In particular, we also determined that HDAC4 can be phosphorylated and simultaneously block the phosphorylation of IRF3 at Ser386 and Ser396 by TBK1 and IKKε, respectively, by interacting with the kinase domain of TBK1 and IKKε. Furthermore, IFN-β may stimulate the expression of HDAC4. Our findings suggest that HDAC4 acts as a regulator of PRR signaling and is a novel mechanism of negative feedback regulation for preventing an overreactive innate immune response.
基金supported by grants from the National Natural Science Foundation of China (No. 30772490)and Special Major National Natural Science Foundation of China (No. 90919051)
文摘BCL2 is a key regulator of apoptosis.Our previous work has demonstrated that special AT-rich sequence-binding protein 1 （SATB1） is positively correlated with BCL2 expression.In the present study,we report a new SATB1 binding site located between P1 and P2 promoters of the BCL2 gene.The candidate SATB1 binding sequence predicted by bioinformatic analysis was investigated in vitro and in vivo by electrophoretic gel mobility shift assays （EMSA） and chromatin immunoprecipitation （ChIP）.One 25-bp sequence,named SB1,was confirmed to be SATB1 binding site.The regulatory function of SB1 and its relevance to SATB1 were further examed with dual-luciferase reporter assay system in Jurkat cells.We found that SB1 could negatively regulate reporter gene activity.Mutation of SATB1 binding site further repressed the activity.Knockdown of SATB1 also enhanced this negative effect of SB1.Our data indicate that the SB1 sequence possesses negative transcriptional regulatory function and this function can be antagonized by SATB1.
基金supported by the National Natural Science Foundation of China(Grant No.82072580 and No.81572789).
文摘Abnormal expression of long interspersed element-1(LINE-1)has been implicated in drug resistance,while our previous study showed that chemotherapy drug paclitaxel(PTX)increased LINE-1 level with unknown mechanism.Bioinformatics analysis suggested the regulation of LINE-1 mRNA by drug-induced stress granules(SGs).This study aimed to explore whether and how SGs are involved in drug-induced LINE-1 increase and thereby promotes drug resistance of triple negative breast cancer(TNBC)cells.We demonstrated that SGs increased LINE-1 expression by recruiting and stabilizing LINE-1 mRNA under drug stress,thereby adapting TNBC cells to chemotherapy drugs.Moreover,LINE-1 inhibitor efavirenz(EFV)could inhibit drug-induced SG to destabilize LINE-1.Our study provides the first evidence of the regulation of LINE-1 by SGs that could be an important survival mechanism for cancer cells exposed to chemotherapy drugs.The findings provide a useful clue for developing new chemotherapeutic strategies against TNBCs.
基金supported by the National Natural Science Foundation of China(No.81802670 and No.82072580).
文摘Objective:The ataxia telangiectasia mutated(ATM)gene is a master regulator in cellular DNA damage response.The dysregulation of ATM expression is frequent in breast cancer,and is known to be involved in the carcinogenesis and prognosis of cancer.However,the underlying mechanism remains unclear.The bioinformatic analysis predicted a potential antisense transcript ATM-antisense(AS)from the opposite strand of the ATM gene.The purpose of this study was to identify ATM-AS and investigate the possible effect of ATM-AS on the ATM gene regulation.Methods:Single strand-specific RT-PCR was performed to verify the predicted antisense transcript ATM-AS within the ATM gene locus.qRT-PCR and Western blotting were used to detect the expression levels of ATM-AS and ATM in normal and breast cancer cell lines as well as in tissue samples.Luciferase reporter gene assays,biological mass spectrometry,ChIP-qPCR and RIP were used to explore the function of ATM-AS in regulating the ATM expression.Immunofluorescence and host-cell reactivation(HCR)assay were performed to evaluate the biological significance of ATM-AS in ATM-mediated DNA damage repair.Breast cancer tissue samples were used for evaluating the correlation of the ATM-AS level with the ATM expression as well as prognosis of the patients.Results:The ATM-AS significantly upregulated the ATM gene activity by recruiting KAT5 histone acetyltransferase to the gene promoter.The reduced ATM-AS level led to the abnormal downregulation of ATM expression,and impaired the ATM-mediated DNA damage repair in normal breast cells in vitro.The ATM-AS level was positively correlated with the ATM expression in the examined breast cancer tissue samples,and the patient prognosis.Conclusion:The present study demonstrated that ATM-AS,an antisense transcript located within the ATM gene body,is an essential positive regulator of ATM expression,and functions by mediating the binding of KAT5 to the ATM promoter.These findings uncover the novel mechanism underlying the dysregulation of the ATM gene in breast cancer,and enrich our understanding of how an antisense transcript regulates its host gene.
基金This work was supported by the National Natural Science Foundation of China(81673436,91853109,81872877,and 91229109)the open fund of State Key Laboratory of Drug Research(SIMM1903KF-10)the Mountain-Climbing Talents Project of Nanjing University to Y.S.
文摘Impairment of glucose(Glu)uptake and storage by skeletal muscle is a prime risk factor for the development of metabolic diseases.Heterogeneous nuclear ribonucleoprotein A1(hnRNP Al)is a highly abundant RNA-binding protein that has been implicated in diverse cellular functions.The aim of this study was to investigate the function of hnRNP A1 on muscle tissue insulin sensitivity and systemic Glu homeostasis.Our results showed that conditional deletion of hnRNP Al in the muscle gave rise to a severe insulin resistance phenotype in mice fed a high-fat diet(HFD).Conditional knockout mice fed a HFD showed exacerbated obesity,insulin resistance,and hepatic steatosis.In vitro interference of hnRNP Al in C2C12 myotubes impaired insulin signal transduction and inhibited Glu uptake,whereas hnRNP Al overexpression in C2C12 myotubes protected against insulin resistance induced by supraphysiological concentrations of insulin.The expression and stability of glycogen synthase(gysl)mRNA were also decreased in the absence of hnRNP A l.Mechanistically,hnRNP Al interacted with gys l and stabilized its mRNA,thereby promoting glycogen synthesis and maintaining the insulin sensitivity in muscle tissue.Taken together,our findings are the first to show that reduced expression of hnRNP Al in skeletal muscle affects the metabolic properties and systemic insulin sensitivity by inhibiting glycogen synthesis.
