Let M_(n,p)=(X_(i,k))_(n×p)be an n×p random matrix whose p columns X^((1)),...,X^((p))are an n-dimensional i.i.d.random sample of size p from 1-dependent Gaussian populations.Instead of investigating the spe...Let M_(n,p)=(X_(i,k))_(n×p)be an n×p random matrix whose p columns X^((1)),...,X^((p))are an n-dimensional i.i.d.random sample of size p from 1-dependent Gaussian populations.Instead of investigating the special case where p and n are comparable,we consider a much more general case in which log n=o(p^(1/3)).We prove that the maximum interpoint distance Mn=max{|X_(i)-X_(j)|;1≤i<j≤n}converges to an extreme-value distribution,where X_(i)and X_(j)denote the i-th and j-th row of M_(n,p),respectively.The proofs are completed by using the Chen-Stein Poisson approximation method and the moderation deviation principle.展开更多
Cancer stem cells(CSCs)are widely acknowledged as primary mediators to the initiation and progression of tumors.The association between microbial infection and cancer stemness has garnered considerable scholarly inter...Cancer stem cells(CSCs)are widely acknowledged as primary mediators to the initiation and progression of tumors.The association between microbial infection and cancer stemness has garnered considerable scholarly interest in recent years.Porphyromonas gingivalis(P.gingivalis)is increasingly considered to be closely related to the development of oral squamous cell carcinoma(OSCC).Nevertheless,the role of P.gingivalis in the stemness of OSCC cells remains uncertain.Herein,we showed that P.gingivalis was positively correlated with CSC markers expression in human OSCC specimens,promoted the stemness and tumorigenicity of OSCC cells,and enhanced tumor formation in nude mice.Mechanistically,P.gingivalis increased lipid synthesis in OSCC cells by upregulating the expression of stearoyl-CoA desaturase 1(SCD1)expression,a key enzyme involved in lipid metabolism,which ultimately resulted in enhanced acquisition of stemness.Moreover,SCD1 suppression attenuated P.gingivalis-induced stemness of OSCC cells,including CSCs markers expression,sphere formation ability,chemoresistance,and tumor growth,in OSCC cells both in vitro and in vivo.Additionally,upregulation of SCD1 in P.gingivalis-infected OSCC cells was associated with the expression of KLF5,and that was modulated by P.gingivalis-activated NOD1 signaling.Taken together,these findings highlight the importance of SCD1-dependent lipid synthesis in P.gingivalis-induced stemness acquisition in OSCC cells,suggest that the NOD1/KLF5 axis may play a key role in regulating SCD1 expression and provide a molecular basis for targeting SCD1 as a new option for attenuating OSCC cells stemness.展开更多
Objective Cerebral palsy(CP)is a prevalent neurodevelopmental disorder acquired during the perinatal period,with periventricular white matter injury(PWMI)serving as its primary pathological hallmark.PWMI is characteri...Objective Cerebral palsy(CP)is a prevalent neurodevelopmental disorder acquired during the perinatal period,with periventricular white matter injury(PWMI)serving as its primary pathological hallmark.PWMI is characterized by the loss of oligodendrocytes(OLs)and the disintegration of myelin sheaths,leading to impaired neural connectivity and motor dysfunction.Neural stem cells(NSCs)represent a promising regenerative source for replenishing lost OLs;however,conventional twodimensional(2D)in vitro culture systems lack the three-dimensional(3D)physiological microenvironment.Microfluidic chip technology has emerged as a powerful tool to overcome this limitation by enabling precise spatial and temporal control over 3D microenvironmental conditions,including the establishment of stable concentration gradients of bioactive molecules.Catalpol,an iridoid glycoside derived from traditional medicinal plants,exhibits dual antioxidant and anti-apoptotic properties.Despite its therapeutic potential,the capacity of catalpol to drive NSC differentiation toward OLs under biomimetic 3D conditions,as well as the underlying molecular mechanisms,remains poorly understood.This study aims to develop a microfluidic-based 3D biomimetic platform to systematically investigate the concentration-dependent effects of catalpol on promoting NSCs-to-OLs differentiation and to elucidate the role of the caveolin-1(Cav-1)signaling pathway in this process.Methods We developed a novel multiplexed microfluidic device featuring parallel microchannels with integrated gradient generators capable of establishing and maintaining precise linear concentration gradients(0-3 g/L catalpol)across 3D NSCs cultures.This platform facilitated the continuous perfusion culture of NSC-derived 3D spheroids,mimicking the dynamic in vivo microenvironment.Real-time cell viability was assessed using Calcein-AM/propidium iodide(PI)dual staining,with fluorescence imaging quantifying live/dead cell ratios.Oligodendrocyte differentiation was evaluated through quantitative reverse transcription polymerase chain reaction(qRT-PCR)for MBP and SOX10 gene expression,complemented by immunofluorescence staining to visualize corresponding protein changes.To dissect the molecular mechanism,the Cav-1-specific pharmacological inhibitor methyl‑β‑cyclodextrin(MCD)was employed to perturb the pathway,and its effects on differentiation markers were analyzed.Results Catalpol demonstrated excellent biocompatibility,with cell viability exceeding 96%across the entire tested concentration range(0-3 g/L),confirming its non-cytotoxic nature.At the optimal concentration of 0-3 g/L,catalpol significantly upregulated both MBP and SOX10 expression(P<0.05,P<0.01),indicating robust promotion of oligodendroglial differentiation.Intriguingly,Cav-1 mRNA expression was progressively downregulated during NSC differentiation into OLs.Further inhibition of Cav-1 with MCD further enhanced this effect,leading to a statistically significant increase in OL-specific gene expression(P<0.05,P<0.01),suggesting Cav-1 acts as a negative regulator of OLs differentiation.Conclusion This study established an integrated microfluidic gradient chip-3D NSC spheroid culture system,which combines the advantages of precise chemical gradient control with physiologically relevant 3D cell culture.The findings demonstrate that 3 g/L catalpol effectively suppresses Cav-1 signaling to drive NSC differentiation into functional OLs.This work not only provides novel insights into the Cav-1-dependent mechanisms of myelination but also delivers a scalable technological platform for future research on remyelination therapies,with potential applications in cerebral palsy and other white matter disorders.The platform’s modular design permits adaptation for screening other neurogenic compounds or investigating additional signaling pathways involved in OLs maturation.展开更多
Background Oxidative stress(OS)is involved in low female fertility by altering multi-omics such as the transcriptome,miRome,and lncRNome in follicular cells and follicular fluid.However,the mechanism by which OS affec...Background Oxidative stress(OS)is involved in low female fertility by altering multi-omics such as the transcriptome,miRome,and lncRNome in follicular cells and follicular fluid.However,the mechanism by which OS affects multiomics dynamics remains largely unknown.Here,we report that OS induces lncRNome dynamics in sow granulosa cells(sGCs),which is partially dependent on the transcription factor activity of its effector,FoxO1.Results A total of 2,283 putative FoxO recognition elements(FREs)were identified in the promoters of 394 lncRNAs,accounting for 91.20%(394/432)of the lncRNAs regulated by OS.ChIP and reporter assays showed that the effector FoxO1 mediated OS regulation of lncRNA transcription in a transcription factor activity-dependent manner.InsGCs,OS induces the transcription and function(e.g.,apoptosis)of NORSF(non-coding RNA involved in sow fertility),a nuclear lncRNA involved in sGC function via FoxO1.Furthermore,FoxO1 has been identified as a transcriptional activator of NORSF in sGCs that interacts with the FRE motif of its promoter.Meanwhile,OS downregulates the transcription of CYP19A1,which encodes an essential enzyme for estrogen synthesis and 17β-estradiol(E2)release by sGCs via the FoxO1 and NORSF axis.Phenotypically,dysregulation of NORSF transcription caused by 2 novel adjacent transitions in the promoter leads to decreased sow fertility.Conclusion These results suggest a model of OS-stimulated lncRNome dynamics in sGCs and a new signaling pathway of OS that influences sGC function and sow fertility.展开更多
Autophagy is an evolutionarily-conserved selfdegradative process that maintains cellular homeostasis by eliminating protein aggregates and damaged organelles.Recently, vesicle-associated membrane protein-associated pr...Autophagy is an evolutionarily-conserved selfdegradative process that maintains cellular homeostasis by eliminating protein aggregates and damaged organelles.Recently, vesicle-associated membrane protein-associated protein B(VAPB), which is associated with the familial form of amyotrophic lateral sclerosis, has been shown to regulate autophagy. In the present study, we demonstrated that knockdown of VAPB induced the up-regulation of beclin 1 expression, which promoted LC3(microtubuleassociated protein light chain 3) conversion and the formation of LC3 puncta, whereas overexpression of VAPB inhibited these processes. The regulation of beclin1 by VAPB was at the transcriptional level. Moreover,knockdown of VAPB increased autophagic flux, which promoted the degradation of the autophagy substrate p62 and neurodegenerative disease proteins. Our study provides evidence that the regulation of autophagy by VAPB is associated with the autophagy-initiating factor beclin 1.展开更多
Emerging evidence indicates that ischemic preconditioning （IPC） induces autophagy which attenuates myocardial ischemia/reperfusion （I/R） injury. However, the precise mechanisms remain com- plex and unclear. The pr...Emerging evidence indicates that ischemic preconditioning （IPC） induces autophagy which attenuates myocardial ischemia/reperfusion （I/R） injury. However, the precise mechanisms remain com- plex and unclear. The present study was to investigate which autophagy pathway was involved in the cardioprotection induced by IPC, so that we can acquire an attractive treatment way for iscbemic heart disease. Adult male Sprague-Dawley （SD） rats were randomly divided into sham group, I/R group and IPC group. IPC was induced with three cycles of 5 min regional ischemia alternating with 5 m^n reper- fusion in a heart I/R model. Samples were taken from the center of the infracted heart and examined by using the electron microscopy, the terminal deoxynucleotidyl transferase-mediated nick end-labeling （TUNEL） method, Western blotting and co-immunoprecipitation （Co-IP）. A large number of autophagic vacuoles were observed in the cardiomyocytes oflPC group as compared with I/R group. LC3-II forma- tion, an autophagy marker, was up-regulated in IPC group as compared with FR group （P〈0.05）. Moreover, the interaction between Beclin 1 and Bcl-2 was significantly increased in IPC group as com- pared with I/R group （P〈0.01）. It was also found that IPC decreased I/R-induced apoptosis （P〈0.01）. These results suggest that IPC inhibits Beclin 1-dependent excessive autophagy in reperfusion phase and cooperates with anti-apoptosis pathway to diminish the cell death induced by the myocardial I/R injury.展开更多
Porphyromonas gingivalis(P.gingivalis),a key pathogen in periodontitis,has been shown to accelerate the progression of atherosclerosis(AS).However,the definite mechanisms remain elusive.Emerging evidence supports an a...Porphyromonas gingivalis(P.gingivalis),a key pathogen in periodontitis,has been shown to accelerate the progression of atherosclerosis(AS).However,the definite mechanisms remain elusive.Emerging evidence supports an association between mitochondrial dysfunction and AS.In our study,the impact of P.gingivalis on mitochondrial dysfunction and the potential mechanism were investigated.The mitochondrial morphology of EA.hy926 cells infected with P.gingivalis was assessed by transmission electron microscopy,mitochondrial staining,and quantitative analysis of the mitochondrial network.Fluorescence staining and flow cytometry analysis were performed to determine mitochondrial reactive oxygen species(mtROS)and mitochondrial membrane potential(MMP)levels.Cellular ATP production was examined by a luminescence assay kit.The expression of key fusion and fission proteins was evaluated by western blot and immunofluorescence.Mdivi-1,a specific Drp1 inhibitor,was used to elucidate the role of Drp1 in mitochondrial dysfunction.Our findings showed that P.gingivalis infection induced mitochondrial fragmentation,increased the mtROS levels,and decreased the MMP and ATP concentration in vascular endothelial cells.We observed upregulation of Drp1(Ser616)phosphorylation and translocation of Drp1 to mitochondria.Mdivi-1 blocked the mitochondrial fragmentation and dysfunction induced by P.gingivalis.Collectively,these results revealed that P.gingivalis infection promoted mitochondrial fragmentation and dysfunction,which was dependent on Drp1.Mitochondrial dysfunction may represent the mechanism by which P.gingivalis exacerbates atherosclerotic lesions.展开更多
Epithelial–mesenchymal transition(EMT)is involved in both physiological and pathological processes.EMT plays an essential role in the invasion,migration and metastasis of tumours.Autophagy has been shown to regulate ...Epithelial–mesenchymal transition(EMT)is involved in both physiological and pathological processes.EMT plays an essential role in the invasion,migration and metastasis of tumours.Autophagy has been shown to regulate EMT in a variety of cancers but not in head and neck squamous cell carcinoma(HNSCC).Herein,we investigated whether autophagy also regulates EMT in HNSCC.Analyses of clinical data from three public databases revealed that higher expression of fibronectin-1(FN1)correlated with poorer prognosis and higher tumour pathological grade in HNSCC.Data from SCC-25 cells demonstrated that rapamycin and Earle’s balanced salt solution(EBSS)promoted autophagy,leading to increased FN1 degradation,while 3-methyladenine(3-MA),bafilomycin A1(Baf A1)and chloroquine(CQ)inhibited autophagy,leading to decreased FN1 degradation.On the other hand,autophagic flux was blocked in BECN1 mutant HNSCC Cal-27 cells,and rapamycin did not promote autophagy in Cal-27 cells;also in addition,FN1 degradation was inhibited.Further,we identified FN1 degradation through the lysosome-dependent degradation pathway using the proteasome inhibitor MG132.Data from immunoprecipitation assays also showed that p62/SQSTM1 participated as an autophagy adapter in the autophagy–lysosome pathway of FN1 degradation.Finally,data from immunoprecipitation assays demonstrated that the interaction between p62 and FN1 was abolished in p62 mutant MCF-7 and A2780 cell lines.These results indicate that autophagy significantly promotes the degradation of FN1.Collectively,our findings clearly suggest that FN1,as a marker of EMT,has adverse effects on HNSCC and elucidate the autophagy–lysosome degradation mechanism of FN1.展开更多
Neonatal growth is characterized by a high protein synthesis rate that is largely due to an enhanced sensitivity to the postprandial rise in insulin and amino acids, especially leucine. The mechanism of leucine＇s act...Neonatal growth is characterized by a high protein synthesis rate that is largely due to an enhanced sensitivity to the postprandial rise in insulin and amino acids, especially leucine. The mechanism of leucine＇s action in vivo is not well understood. In this study, we investigated the effect of leucine infusion on protein synthesis in skeletal muscle and liver of neonatal pigs. To evaluate the mode of action of leucine, we used rapamycin, an inhibitor of mammalian target of rapamycin （mTOR） complex-1 （mTORC1）. Overnight-fasted 7-day-old piglets were treated with rapamycin for 1 hour and then infused with leucine （400 μmol·kg^-1·h^-1） for 1 hour. Leucine infusion increased the rate of protein synthesis, and ribosomal protein S6 kinase 1 （S6K1） and eukaryotic initiation factor （elF） 4E-binding protein-1 （4E-BP1） phosphorylation in gastrocnemius and masseter muscles （P 〈 0.05）, but not in the liver. The leucine-induced stimulation of protein synthesis and S6K1 and 4E-BP1 phosphorylation were completely blocked by rapamycin, suggesting that leucine action is by an mTORC1-dependent mechanism. Neither leucine nor rapamycin had any effect on the activation of the upstream mTQRC1 regulators, AMP-activated protein kinase and protein kinase B, in skeletal muscle or liver. The activation of elF2α and elongation factor 2 was not affected by leucine or rapamycin, indicating that these two pathways are not limiting steps of leucine-induced protein synthesis. These results suggest that leucine stimulates muscle protein synthesis in neonatal pigs by inducing the activation of mTORC1 and its downstream pathway leading to mRNA translation.展开更多
Aldosterone mediates many of the physiological and pathophysiological/cardio-toxic effects of angiotensin II(Ang II). Its synthesis and secretion from the zona glomerulosa cells of the adrenal cortex, elevated in chro...Aldosterone mediates many of the physiological and pathophysiological/cardio-toxic effects of angiotensin II(Ang II). Its synthesis and secretion from the zona glomerulosa cells of the adrenal cortex, elevated in chronic heart failure(HF), is induced by Ang II type 1 receptors(AT1Rs). The AT1R is a G protein-coupled receptor, mainly coupling to Gq/11 proteins. However, it can also signal through β-arrestin-1(βarr1) or-2(βarr2), both of which mediate G protein-independent signaling. Over the past decade, a second, Gq/11 proteinindependent but βarr1-dependent signaling pathway emanating from the adrenocortical AT1R and leading to aldosterone production has become appreciated. Thus, it became apparent that AT1R antagonists that block both pathways equally well are warranted for fully effective aldosterone suppression in HF. This spurred the comparison of all of the currently marketed angiotensin receptor blockers(ARBs, AT1R antagonists or sartans) at blocking activation of the two signaling modes(G protein-, and βarr1-dependent) at the Ang IIactivated AT1R and hence, at suppression of aldosterone in vitro and in vivo. Although all agents are very potent inhibitors of G protein activation at the AT1R, candesartan and valsartan were uncovered to be the most potent ARBs at blocking βarr activation by Ang II and at suppressing aldosterone in vitro and in vivo in post-myocardial infarction HF animals. In contrast, irbesartan and losartan are virtually G protein-"biased" blockers at the human AT1R, with very low efficacy for βarr inhibition and aldosterone suppression. Therefore, candesartan and valsartan(and other, structurally similar compounds) may be the most preferred ARB agents for HF pharmacotherapy, as well as for treatment of other conditions characterized by elevated aldosterone.展开更多
Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is...Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is a natural active component in Panax ginseng C.A.Meyer,and some of them enhance thermogenesis.However,there are few studies on the mechanism and target of ginsenosides enhancing thermogenesis.Using thermogenic protein uncoupling protein 1(UCP1)-luciferase reporter assay,we identifi ed ginsenoside F1 as a novel UCP1 activator in the ginsenosides library.Using pull down assay and inhibitor interference,we found F1 binds toβ3-adrenergic receptors(β3-AR)to enhance UCP1 expression via cAMP/PKA/CREB pathway.We also investigated the ability of F1 on energy metabolism in obesity-induced diabetic mice,including body weight,body composition and energy expenditure.The results of proteomics showed that F1 signifi cantly up-regulated thermogenesis proteins and lipolytic proteins,but down-regulated fatty acid synthesis proteins.Ginsenoside F1 increased thermogenesis and ameliorated insulin resistance specifi cally by promoting the browning of white adipose tissue in obese mice.Additionally,ginsenoside F1 improves norepinephrine-induced insulin resistance in adipocytes and hepatocytes,and shows a stronger mitochondria respiration ability than norepinephrine.These fi ndings suggest that ginsenoside F1 is a promising lead compound in the improvement of insulin resistance.展开更多
Objective We aimed to explore how fermented barley extracts with Lactobacillus plantarum dy-1(LFBE) affected the browning in adipocytes and obese rats.Methods In vitro, 3T3-L1 cells were induced by LFBE, raw barley ex...Objective We aimed to explore how fermented barley extracts with Lactobacillus plantarum dy-1(LFBE) affected the browning in adipocytes and obese rats.Methods In vitro, 3T3-L1 cells were induced by LFBE, raw barley extraction(RBE) and polyphenol compounds(PC) from LFBE to evaluate the adipocyte differentiation.In vivo, obese SD rats induced by high fat diet(HFD) were randomly divided into three groups treated with oral gavage:(a) normal control diet with distilled water,(b) HFD with distilled water,(c) HFD with 800 mg LFBE/kg body weight(bw).Results In vitro, LFBE and the PC in the extraction significantly inhibited adipogenesis and potentiated browning of 3T3-L1 preadipocytes, rather than RBE.In vivo, we observed remarkable decreases in the body weight, serum lipid levels, white adipose tissue(WAT) weights and cell sizes of brown adipose tissues(BAT) in the LFBE group after 10 weeks.LFBE group could gain more mass of interscapular BAT(IBAT) and promote the dehydrogenase activity in the mitochondria.And LFBE may potentiate process of the IBAT thermogenesis and epididymis adipose tissue(EAT) browning via activating the uncoupling protein 1(UCP1)-dependent mechanism to suppress the obesity.Conclusion These results demonstrated that LFBE decreased obesity partly by increasing the BAT mass and the energy expenditure by activating BAT thermogenesis and WAT browning in a UCP1-dependent mechanism.展开更多
AIM： To observe the relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and cytochrome P450 2E1 （CYP2E1） activity, in order to address if inhibition of CYP2E1 could attenuate...AIM： To observe the relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and cytochrome P450 2E1 （CYP2E1） activity, in order to address if inhibition of CYP2E1 could attenuate ethanol- induced cellular damage. METHODS： The dose-dependent （25-100 mmol/L） and time-dependent （0-24 h） exposures of primary human cultured hepatocytes to ethanol were carried out. CYP2E1 activity and protein expression were detected by spectrophotometer and Western blot analysis respectively. Hepatotoxicity was investigated by determination of lactate dehydrogenase （LDH） and aspartate transaminase （AST） level in hepatocyte culture supernatants, as well as the intracellular formation of malondialdehyde （MDA）. RESULTS： A dose-and time-dependent response between ethanol exposure and CYP2E1 activity in human hepatocytes was demonstrated. Moreover, there was a time-dependent increase of CYP2E1 protein after 100 mmol/L ethanol exposure. Meanwhile, ethanol exposure of hepatocytes caused a time-dependent increase of cellular MDA level, LDH, and AST activities in supernatants. Furthermore, the inhibitor of CYP2E1, diallyl sulfide （DAS） could partly attenuate the increases of MDA, LDH, and AST in human hepatocytes. CONCLUSION： A positive relationship between ethanolinduced oxidative damage in human primary cultured hepatocytes and CYP2E1 activity was exhibited, and the inhibition of CYP2E1 could partly attenuate ethanol-induced oxidative damage.展开更多
BACKGROUND Folic acid has been shown to improve non-alcoholic steatohepatitis(NASH),but its roles in hepatic lipid metabolism,hepatic one-carbon metabolism,and gut microbiota are still unknown.AIM To demonstrate the r...BACKGROUND Folic acid has been shown to improve non-alcoholic steatohepatitis(NASH),but its roles in hepatic lipid metabolism,hepatic one-carbon metabolism,and gut microbiota are still unknown.AIM To demonstrate the role of folic acid in lipid metabolism and gut microbiota in NASH.METHODS Twenty-four Sprague-Dawley rats were assigned into three groups:Chow diet,high-fat diet(HFD),and HFD with folic acid administration.At the end of 16 wk,the liver histology,the expression of hepatic genes related to lipid metabolism,one-carbon metabolism,and gut microbiota structure analysis of fecal samples based on 16 S r RNA sequencing were measured to evaluate the effect of folic acid.Palmitic acid-exposed Huh7 cell line was used to evaluate the role of folic acid in hepatic lipid metabolism.RESULTS Folic acid treatment attenuated steatosis,lobular inflammation,and hepatocellular ballooning in rats with HFD-induced steatohepatitis.Genes related to lipid de novo lipogenesis,β-oxidation,and lipid uptake were improvedin HFD-fed folic acid-treated rats.Furthermore,peroxisome proliferator-activated receptor alpha(PPARα)and silence information regulation factor 1(SIRT1)were restored by folic acid in HFD-fed rats and palmitic acid-exposed Huh7 cell line.The restoration of PPARαby folic acid was blocked after transfection with SIRT1 si RNA in the Huh7 cell line.Additionally,folic acid administration ameliorated depleted hepatic one-carbon metabolism and restored the diversity of the gut microbiota in rats with HFD-induced steatohepatitis.CONCLUSION Folic acid improves hepatic lipid metabolism by upregulating PPARαlevels via a SIRT1-dependent mechanism and restores hepatic one-carbon metabolism and diversity of gut microbiota,thereby attenuating HFD-induced NASH in rats.展开更多
Cyclin-dependent kinase 1 (CDK1) plays an essential role in cell cycle regulation.However,as mouse Cdk1embryos die early,the role of CDK1 in regulating the cell cycle and embryo development remains unclear.Here,we sho...Cyclin-dependent kinase 1 (CDK1) plays an essential role in cell cycle regulation.However,as mouse Cdk1embryos die early,the role of CDK1 in regulating the cell cycle and embryo development remains unclear.Here,we showed that zebrafish cdk1^(-/-)embryos exhibit severe microphthalmia accompanied by multiple defects in S phase entry,M phase progression,and cell differentiation but not in interkinetic nuclear migration.We identified Top2a as a potential downstream target and cyclin A2 and cyclin B1 as partners of Cdk1 in cell cycle regulation via an in silico analysis.While depletion of either cyclin A2 or Top2a led to the decreased S phase entry in zebrafish retinal cells,the depletion of cyclin B1 led to M phase arrest.Moreover,phosphorylation of Top2a at serine 1213 (S1213) was nearly abolished in both cdk1 and ccna2mutants,but not in ccnb1 mutants.Furthermore,overexpression of TOP2A^(S1213D),the phosphomimetic form of human TOP2A,rescued S phase entry and alleviated the microphthalmia defects in both cdk1^(-/-)and ccna2^(-/-)embryos.Taken together,our data suggest that Cdk1 interacts with cyclin A2 to regulate S phase entry partially through Top2a phosphorylation and interacts with cyclin B1 to regulate M phase progression.展开更多
Objective:Cardiac hypertrophy and fibrosis are major pathological manifestations observed in left ventricular remodeling induced by angiotensin II(AngII).Low-intensity pulsed ultrasound(LIPUS)has been reported to amel...Objective:Cardiac hypertrophy and fibrosis are major pathological manifestations observed in left ventricular remodeling induced by angiotensin II(AngII).Low-intensity pulsed ultrasound(LIPUS)has been reported to ameliorate cardiac dysfunction and myocardial fibrosis in myocardial infarction(MI)through mechano-transduction and its downstream pathways.In this study,we aimed to investigate whether LIPUS could exert a protective effect by ameliorating AngII-induced cardiac hypertrophy and fibrosis and if so,to further elucidate the underlying molecular mechanisms.Methods:We used AngII to mimic animal and cell culture models of cardiac hypertrophy and fibrosis.LIPUS irradiation was applied in vivo for 20 min every 2 d from one week before mini-pump implantation to four weeks after mini-pump implantation,and in vitro for 20 min on each of two occasions 6 h apart.Cardiac hypertrophy and fibrosis levels were then evaluated by echocardiographic,histopathological,and molecular biological methods.Results:Our results showed that LIPUS could ameliorate left ventricular remodeling in vivo and cardiac fibrosis in vitro by reducing AngII-induced release of inflammatory cytokines,but the protective effects on cardiac hypertrophy were limited in vitro.Given that LIPUS increased the expression of caveolin-1 in response to mechanical stimulation,we inhibited caveolin-1 activity with pyrazolopyrimidine 2(pp2)in vivo and in vitro.LIPUS-induced downregulation of inflammation was reversed and the anti-fibrotic effects of LIPUS were absent.Conclusions:These results indicated that LIPUS could ameliorate AngII-induced cardiac fibrosis by alleviating inflammation via a caveolin-1-dependent pathway,providing new insights for the development of novel therapeutic apparatus in clinical practice.展开更多
Background: The histone code is an established epigenetic regulator of early embryonic development in mammals.The lysine residue K9 of histone H3(H3 K9) is a prime target of SIRT1, a member of NAD+-dependent histone d...Background: The histone code is an established epigenetic regulator of early embryonic development in mammals.The lysine residue K9 of histone H3(H3 K9) is a prime target of SIRT1, a member of NAD+-dependent histone deacetylase family of enzymes targeting both histone and non-histone substrates. At present, little is known about SIRT1-modulation of H3 K9 in zygotic pronuclei and its association with the success of preimplantation embryo development. Therefore, we evaluated the effect of SIRT1 activity on H3 K9 methylation and acetylation in porcine zygotes and the significance of H3 K9 modifications for early embryonic development.Results: Our results show that SIRT1 activators resveratrol and BML-278 increased H3 K9 methylation and suppressed H3 K9 acetylation in both the paternal and maternal pronucleus. Inversely, SIRT1 inhibitors nicotinamide and sirtinol suppressed methylation and increased acetylation of pronuclear H3 K9. Evaluation of early embryonic development confirmed positive effect of selective SIRT1 activation on blastocyst formation rate(5.2 ± 2.9% versus 32.9 ± 8.1% in vehicle control and BML-278 group, respectively; P ≤ 0.05). Stimulation of SIRT1 activity coincided with fluorometric signal intensity of ooplasmic ubiquitin ligase MDM2, a known substrate of SIRT1 and known limiting factor of epigenome remodeling.Conclusions: We conclude that SIRT1 modulates zygotic histone code, obviously through direct deacetylation and via non-histone targets resulting in increased H3 K9 me3. These changes in zygotes lead to more successful pre-implantation embryonic development and, indeed, the specific SIRT1 activation due to BML-278 is beneficial for in vitro embryo production and blastocyst achievement.展开更多
AIM:To evaluate the effects of LIN28A(human)on high glucose-induced retinal pigmented epithelium(RPE)cell injury and its possible mechanism.METHODS:Diabetic retinopathy model was generated following 48h of exposure to...AIM:To evaluate the effects of LIN28A(human)on high glucose-induced retinal pigmented epithelium(RPE)cell injury and its possible mechanism.METHODS:Diabetic retinopathy model was generated following 48h of exposure to 30 mmol/L high glucose(HG)in ARPE-19 cells.Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blot tested the expression of the corresponding genes and proteins.Cell viability as well as apoptosis was determined through cell counting kit-8(CCK-8)and flow cytometry assays.Immunofluorescence assay was adopted to evaluate autophagy activity.Caspase 3 activity,oxidative stress markers,and cytokines were appraised adopting their commercial kits,respectively.Finally,ARPE-19 cells were preincubated with EX527,a Sirtuin 1(SIRT1)inhibitor,prior to HG stimulation to validate the regulatory mechanism.RESULTS:LIN28A was downregulated in HG-challenged ARPE-19 cells.LIN28A overexpression greatly inhibited HGinduced ARPE-19 cell viability loss,apoptosis,oxidative damage as well as inflammatory response.Meanwhile,the repressed autophagy and SIRT1 in ARPE-19 cells challenged with HG were elevated after LIN28A overexpression.In addition,treatment of EX527 greatly inhibited the activated autophagy following LIN28A overexpression and partly abolished the protective role of LIN28A against HG-elicited apoptosis,oxidative damage as well as inflammation in ARPE-19 cells.CONCLUSION:LIN28A exerts a protective role against HG-elicited RPE oxidative damage,inflammation,as well as apoptosis via regulating SIRT1/autophagy.展开更多
Oral mucosal inflammatory responses to P. gingivalis and its key virulence factor, lipopolysaccharide (LPS), are characterized by a massive rise in proinflammatory cytokine production, up-regu- lation in mitogen-activ...Oral mucosal inflammatory responses to P. gingivalis and its key virulence factor, lipopolysaccharide (LPS), are characterized by a massive rise in proinflammatory cytokine production, up-regu- lation in mitogen-activated protein kinase (MAPK) cascade, and the induction in epidermal growth factor receptor (EGFR) activation. In this study, we report that stimulation of salivary gland acinar cells with P. gingivalis LPS leads to p38 MAPK-dependent release of soluble TGF-α ligand and the increase in EGFR phosphorylation. Further, we show that the LPS-induced TGF-α shedding and EGFR transactivation involve the activation of membrane-associated metalloprotease, TACE also known as ADAM17, through phosphorylation by p38 MAPK, and require Rac1 participation. Moreover, we demonstrate that blocking the Rac1 activation leads to the suppression in the membrane translocation of Rac1 as well as p38, thus indicating that the LPS-elicited p38 membrane recruitment for TACE phosphorylation requires colocalization with Rac1. Hence, our findings imply that Rac1 membrane translocation serves as an essential platform for the localization of p38 with TACE, TGF-α ectodomain shedding, and the EGFR activation.展开更多
AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a no...AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a normal human liver cell line.METHODS： Net Ca^2＋ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPCl were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.RESULTS： Ca^2＋ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 （a non-selective Ca^2＋ channel blocker）; 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2＋ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION： In HL-7702 cells, there is a type of TRPCl-dependent Ca^2＋ channel, which could be detected v/a NMT and inhibited by La^3＋.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.1177117812171198)+2 种基金the Science and Technology Development Program of Jilin Province(Grant No.20210101467JC)the Technology Program of Jilin Educational Department During the“14th Five-Year”Plan Period(Grant No.JJKH20241239KJ)the Fundamental Research Funds for the Central Universities.
文摘Let M_(n,p)=(X_(i,k))_(n×p)be an n×p random matrix whose p columns X^((1)),...,X^((p))are an n-dimensional i.i.d.random sample of size p from 1-dependent Gaussian populations.Instead of investigating the special case where p and n are comparable,we consider a much more general case in which log n=o(p^(1/3)).We prove that the maximum interpoint distance Mn=max{|X_(i)-X_(j)|;1≤i<j≤n}converges to an extreme-value distribution,where X_(i)and X_(j)denote the i-th and j-th row of M_(n,p),respectively.The proofs are completed by using the Chen-Stein Poisson approximation method and the moderation deviation principle.
基金supported by the National Natural Science Foundation of China(grant#82370975 and 82170969)。
文摘Cancer stem cells(CSCs)are widely acknowledged as primary mediators to the initiation and progression of tumors.The association between microbial infection and cancer stemness has garnered considerable scholarly interest in recent years.Porphyromonas gingivalis(P.gingivalis)is increasingly considered to be closely related to the development of oral squamous cell carcinoma(OSCC).Nevertheless,the role of P.gingivalis in the stemness of OSCC cells remains uncertain.Herein,we showed that P.gingivalis was positively correlated with CSC markers expression in human OSCC specimens,promoted the stemness and tumorigenicity of OSCC cells,and enhanced tumor formation in nude mice.Mechanistically,P.gingivalis increased lipid synthesis in OSCC cells by upregulating the expression of stearoyl-CoA desaturase 1(SCD1)expression,a key enzyme involved in lipid metabolism,which ultimately resulted in enhanced acquisition of stemness.Moreover,SCD1 suppression attenuated P.gingivalis-induced stemness of OSCC cells,including CSCs markers expression,sphere formation ability,chemoresistance,and tumor growth,in OSCC cells both in vitro and in vivo.Additionally,upregulation of SCD1 in P.gingivalis-infected OSCC cells was associated with the expression of KLF5,and that was modulated by P.gingivalis-activated NOD1 signaling.Taken together,these findings highlight the importance of SCD1-dependent lipid synthesis in P.gingivalis-induced stemness acquisition in OSCC cells,suggest that the NOD1/KLF5 axis may play a key role in regulating SCD1 expression and provide a molecular basis for targeting SCD1 as a new option for attenuating OSCC cells stemness.
基金supported by grants from the Liaoning Province Excellent Talent Program Project(XLYC1902031)Dalian Science and Technology Talent Innovation Plan Grant(2022RG18)Basic Research Project of the Department of Education of Liaoning Province(LJKQZ20222395)。
文摘Objective Cerebral palsy(CP)is a prevalent neurodevelopmental disorder acquired during the perinatal period,with periventricular white matter injury(PWMI)serving as its primary pathological hallmark.PWMI is characterized by the loss of oligodendrocytes(OLs)and the disintegration of myelin sheaths,leading to impaired neural connectivity and motor dysfunction.Neural stem cells(NSCs)represent a promising regenerative source for replenishing lost OLs;however,conventional twodimensional(2D)in vitro culture systems lack the three-dimensional(3D)physiological microenvironment.Microfluidic chip technology has emerged as a powerful tool to overcome this limitation by enabling precise spatial and temporal control over 3D microenvironmental conditions,including the establishment of stable concentration gradients of bioactive molecules.Catalpol,an iridoid glycoside derived from traditional medicinal plants,exhibits dual antioxidant and anti-apoptotic properties.Despite its therapeutic potential,the capacity of catalpol to drive NSC differentiation toward OLs under biomimetic 3D conditions,as well as the underlying molecular mechanisms,remains poorly understood.This study aims to develop a microfluidic-based 3D biomimetic platform to systematically investigate the concentration-dependent effects of catalpol on promoting NSCs-to-OLs differentiation and to elucidate the role of the caveolin-1(Cav-1)signaling pathway in this process.Methods We developed a novel multiplexed microfluidic device featuring parallel microchannels with integrated gradient generators capable of establishing and maintaining precise linear concentration gradients(0-3 g/L catalpol)across 3D NSCs cultures.This platform facilitated the continuous perfusion culture of NSC-derived 3D spheroids,mimicking the dynamic in vivo microenvironment.Real-time cell viability was assessed using Calcein-AM/propidium iodide(PI)dual staining,with fluorescence imaging quantifying live/dead cell ratios.Oligodendrocyte differentiation was evaluated through quantitative reverse transcription polymerase chain reaction(qRT-PCR)for MBP and SOX10 gene expression,complemented by immunofluorescence staining to visualize corresponding protein changes.To dissect the molecular mechanism,the Cav-1-specific pharmacological inhibitor methyl‑β‑cyclodextrin(MCD)was employed to perturb the pathway,and its effects on differentiation markers were analyzed.Results Catalpol demonstrated excellent biocompatibility,with cell viability exceeding 96%across the entire tested concentration range(0-3 g/L),confirming its non-cytotoxic nature.At the optimal concentration of 0-3 g/L,catalpol significantly upregulated both MBP and SOX10 expression(P<0.05,P<0.01),indicating robust promotion of oligodendroglial differentiation.Intriguingly,Cav-1 mRNA expression was progressively downregulated during NSC differentiation into OLs.Further inhibition of Cav-1 with MCD further enhanced this effect,leading to a statistically significant increase in OL-specific gene expression(P<0.05,P<0.01),suggesting Cav-1 acts as a negative regulator of OLs differentiation.Conclusion This study established an integrated microfluidic gradient chip-3D NSC spheroid culture system,which combines the advantages of precise chemical gradient control with physiologically relevant 3D cell culture.The findings demonstrate that 3 g/L catalpol effectively suppresses Cav-1 signaling to drive NSC differentiation into functional OLs.This work not only provides novel insights into the Cav-1-dependent mechanisms of myelination but also delivers a scalable technological platform for future research on remyelination therapies,with potential applications in cerebral palsy and other white matter disorders.The platform’s modular design permits adaptation for screening other neurogenic compounds or investigating additional signaling pathways involved in OLs maturation.
基金supported by the National Key R&D Program of China(2022YFD1600903)the National Natural Science Foundation of China(32272842)。
文摘Background Oxidative stress(OS)is involved in low female fertility by altering multi-omics such as the transcriptome,miRome,and lncRNome in follicular cells and follicular fluid.However,the mechanism by which OS affects multiomics dynamics remains largely unknown.Here,we report that OS induces lncRNome dynamics in sow granulosa cells(sGCs),which is partially dependent on the transcription factor activity of its effector,FoxO1.Results A total of 2,283 putative FoxO recognition elements(FREs)were identified in the promoters of 394 lncRNAs,accounting for 91.20%(394/432)of the lncRNAs regulated by OS.ChIP and reporter assays showed that the effector FoxO1 mediated OS regulation of lncRNA transcription in a transcription factor activity-dependent manner.InsGCs,OS induces the transcription and function(e.g.,apoptosis)of NORSF(non-coding RNA involved in sow fertility),a nuclear lncRNA involved in sGC function via FoxO1.Furthermore,FoxO1 has been identified as a transcriptional activator of NORSF in sGCs that interacts with the FRE motif of its promoter.Meanwhile,OS downregulates the transcription of CYP19A1,which encodes an essential enzyme for estrogen synthesis and 17β-estradiol(E2)release by sGCs via the FoxO1 and NORSF axis.Phenotypically,dysregulation of NORSF transcription caused by 2 novel adjacent transitions in the promoter leads to decreased sow fertility.Conclusion These results suggest a model of OS-stimulated lncRNome dynamics in sGCs and a new signaling pathway of OS that influences sGC function and sow fertility.
基金supported in part by the National Key R&D Program of China (2016YFC1306000)the National Natural Sciences Foundation of China (31330030, 31471012, and 81761148024)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Autophagy is an evolutionarily-conserved selfdegradative process that maintains cellular homeostasis by eliminating protein aggregates and damaged organelles.Recently, vesicle-associated membrane protein-associated protein B(VAPB), which is associated with the familial form of amyotrophic lateral sclerosis, has been shown to regulate autophagy. In the present study, we demonstrated that knockdown of VAPB induced the up-regulation of beclin 1 expression, which promoted LC3(microtubuleassociated protein light chain 3) conversion and the formation of LC3 puncta, whereas overexpression of VAPB inhibited these processes. The regulation of beclin1 by VAPB was at the transcriptional level. Moreover,knockdown of VAPB increased autophagic flux, which promoted the degradation of the autophagy substrate p62 and neurodegenerative disease proteins. Our study provides evidence that the regulation of autophagy by VAPB is associated with the autophagy-initiating factor beclin 1.
基金supported by the Pathology Laboratory, Immunology Laboratory, General Surgery Laboratory and Animal Laboratory of Tongji Medical College,Huazhong University of Science and Technology
文摘Emerging evidence indicates that ischemic preconditioning （IPC） induces autophagy which attenuates myocardial ischemia/reperfusion （I/R） injury. However, the precise mechanisms remain com- plex and unclear. The present study was to investigate which autophagy pathway was involved in the cardioprotection induced by IPC, so that we can acquire an attractive treatment way for iscbemic heart disease. Adult male Sprague-Dawley （SD） rats were randomly divided into sham group, I/R group and IPC group. IPC was induced with three cycles of 5 min regional ischemia alternating with 5 m^n reper- fusion in a heart I/R model. Samples were taken from the center of the infracted heart and examined by using the electron microscopy, the terminal deoxynucleotidyl transferase-mediated nick end-labeling （TUNEL） method, Western blotting and co-immunoprecipitation （Co-IP）. A large number of autophagic vacuoles were observed in the cardiomyocytes oflPC group as compared with I/R group. LC3-II forma- tion, an autophagy marker, was up-regulated in IPC group as compared with FR group （P〈0.05）. Moreover, the interaction between Beclin 1 and Bcl-2 was significantly increased in IPC group as com- pared with I/R group （P〈0.01）. It was also found that IPC decreased I/R-induced apoptosis （P〈0.01）. These results suggest that IPC inhibits Beclin 1-dependent excessive autophagy in reperfusion phase and cooperates with anti-apoptosis pathway to diminish the cell death induced by the myocardial I/R injury.
基金supported by grants from National Natural Science Foundation of China(NO.81970943,81870771)。
文摘Porphyromonas gingivalis(P.gingivalis),a key pathogen in periodontitis,has been shown to accelerate the progression of atherosclerosis(AS).However,the definite mechanisms remain elusive.Emerging evidence supports an association between mitochondrial dysfunction and AS.In our study,the impact of P.gingivalis on mitochondrial dysfunction and the potential mechanism were investigated.The mitochondrial morphology of EA.hy926 cells infected with P.gingivalis was assessed by transmission electron microscopy,mitochondrial staining,and quantitative analysis of the mitochondrial network.Fluorescence staining and flow cytometry analysis were performed to determine mitochondrial reactive oxygen species(mtROS)and mitochondrial membrane potential(MMP)levels.Cellular ATP production was examined by a luminescence assay kit.The expression of key fusion and fission proteins was evaluated by western blot and immunofluorescence.Mdivi-1,a specific Drp1 inhibitor,was used to elucidate the role of Drp1 in mitochondrial dysfunction.Our findings showed that P.gingivalis infection induced mitochondrial fragmentation,increased the mtROS levels,and decreased the MMP and ATP concentration in vascular endothelial cells.We observed upregulation of Drp1(Ser616)phosphorylation and translocation of Drp1 to mitochondria.Mdivi-1 blocked the mitochondrial fragmentation and dysfunction induced by P.gingivalis.Collectively,these results revealed that P.gingivalis infection promoted mitochondrial fragmentation and dysfunction,which was dependent on Drp1.Mitochondrial dysfunction may represent the mechanism by which P.gingivalis exacerbates atherosclerotic lesions.
基金This work was supported by grants from the National Natural Science Foundation of China(881320108011,81600823,81920108012,81870741)China Postdoctoral Science Foundation(2017M611332,2019M661177)+2 种基金Provincial Science Foundation of Jilin Provincial Department of Finance(JLS22019378-28)Bethune Project of Jilin University(2018A06,2015340)Jilin Scientific and Technological Development Programme(20170101093JC).
文摘Epithelial–mesenchymal transition(EMT)is involved in both physiological and pathological processes.EMT plays an essential role in the invasion,migration and metastasis of tumours.Autophagy has been shown to regulate EMT in a variety of cancers but not in head and neck squamous cell carcinoma(HNSCC).Herein,we investigated whether autophagy also regulates EMT in HNSCC.Analyses of clinical data from three public databases revealed that higher expression of fibronectin-1(FN1)correlated with poorer prognosis and higher tumour pathological grade in HNSCC.Data from SCC-25 cells demonstrated that rapamycin and Earle’s balanced salt solution(EBSS)promoted autophagy,leading to increased FN1 degradation,while 3-methyladenine(3-MA),bafilomycin A1(Baf A1)and chloroquine(CQ)inhibited autophagy,leading to decreased FN1 degradation.On the other hand,autophagic flux was blocked in BECN1 mutant HNSCC Cal-27 cells,and rapamycin did not promote autophagy in Cal-27 cells;also in addition,FN1 degradation was inhibited.Further,we identified FN1 degradation through the lysosome-dependent degradation pathway using the proteasome inhibitor MG132.Data from immunoprecipitation assays also showed that p62/SQSTM1 participated as an autophagy adapter in the autophagy–lysosome pathway of FN1 degradation.Finally,data from immunoprecipitation assays demonstrated that the interaction between p62 and FN1 was abolished in p62 mutant MCF-7 and A2780 cell lines.These results indicate that autophagy significantly promotes the degradation of FN1.Collectively,our findings clearly suggest that FN1,as a marker of EMT,has adverse effects on HNSCC and elucidate the autophagy–lysosome degradation mechanism of FN1.
文摘Neonatal growth is characterized by a high protein synthesis rate that is largely due to an enhanced sensitivity to the postprandial rise in insulin and amino acids, especially leucine. The mechanism of leucine＇s action in vivo is not well understood. In this study, we investigated the effect of leucine infusion on protein synthesis in skeletal muscle and liver of neonatal pigs. To evaluate the mode of action of leucine, we used rapamycin, an inhibitor of mammalian target of rapamycin （mTOR） complex-1 （mTORC1）. Overnight-fasted 7-day-old piglets were treated with rapamycin for 1 hour and then infused with leucine （400 μmol·kg^-1·h^-1） for 1 hour. Leucine infusion increased the rate of protein synthesis, and ribosomal protein S6 kinase 1 （S6K1） and eukaryotic initiation factor （elF） 4E-binding protein-1 （4E-BP1） phosphorylation in gastrocnemius and masseter muscles （P 〈 0.05）, but not in the liver. The leucine-induced stimulation of protein synthesis and S6K1 and 4E-BP1 phosphorylation were completely blocked by rapamycin, suggesting that leucine action is by an mTORC1-dependent mechanism. Neither leucine nor rapamycin had any effect on the activation of the upstream mTQRC1 regulators, AMP-activated protein kinase and protein kinase B, in skeletal muscle or liver. The activation of elF2α and elongation factor 2 was not affected by leucine or rapamycin, indicating that these two pathways are not limiting steps of leucine-induced protein synthesis. These results suggest that leucine stimulates muscle protein synthesis in neonatal pigs by inducing the activation of mTORC1 and its downstream pathway leading to mRNA translation.
文摘Aldosterone mediates many of the physiological and pathophysiological/cardio-toxic effects of angiotensin II(Ang II). Its synthesis and secretion from the zona glomerulosa cells of the adrenal cortex, elevated in chronic heart failure(HF), is induced by Ang II type 1 receptors(AT1Rs). The AT1R is a G protein-coupled receptor, mainly coupling to Gq/11 proteins. However, it can also signal through β-arrestin-1(βarr1) or-2(βarr2), both of which mediate G protein-independent signaling. Over the past decade, a second, Gq/11 proteinindependent but βarr1-dependent signaling pathway emanating from the adrenocortical AT1R and leading to aldosterone production has become appreciated. Thus, it became apparent that AT1R antagonists that block both pathways equally well are warranted for fully effective aldosterone suppression in HF. This spurred the comparison of all of the currently marketed angiotensin receptor blockers(ARBs, AT1R antagonists or sartans) at blocking activation of the two signaling modes(G protein-, and βarr1-dependent) at the Ang IIactivated AT1R and hence, at suppression of aldosterone in vitro and in vivo. Although all agents are very potent inhibitors of G protein activation at the AT1R, candesartan and valsartan were uncovered to be the most potent ARBs at blocking βarr activation by Ang II and at suppressing aldosterone in vitro and in vivo in post-myocardial infarction HF animals. In contrast, irbesartan and losartan are virtually G protein-"biased" blockers at the human AT1R, with very low efficacy for βarr inhibition and aldosterone suppression. Therefore, candesartan and valsartan(and other, structurally similar compounds) may be the most preferred ARB agents for HF pharmacotherapy, as well as for treatment of other conditions characterized by elevated aldosterone.
基金supported by the National Natural Science Foundation of China[31872674]the Jilin Talent Development Foundation Grant[20200301018RQ]the Fundamental Research Funds for the Central Universities[CGZH202206].
文摘Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is a natural active component in Panax ginseng C.A.Meyer,and some of them enhance thermogenesis.However,there are few studies on the mechanism and target of ginsenosides enhancing thermogenesis.Using thermogenic protein uncoupling protein 1(UCP1)-luciferase reporter assay,we identifi ed ginsenoside F1 as a novel UCP1 activator in the ginsenosides library.Using pull down assay and inhibitor interference,we found F1 binds toβ3-adrenergic receptors(β3-AR)to enhance UCP1 expression via cAMP/PKA/CREB pathway.We also investigated the ability of F1 on energy metabolism in obesity-induced diabetic mice,including body weight,body composition and energy expenditure.The results of proteomics showed that F1 signifi cantly up-regulated thermogenesis proteins and lipolytic proteins,but down-regulated fatty acid synthesis proteins.Ginsenoside F1 increased thermogenesis and ameliorated insulin resistance specifi cally by promoting the browning of white adipose tissue in obese mice.Additionally,ginsenoside F1 improves norepinephrine-induced insulin resistance in adipocytes and hepatocytes,and shows a stronger mitochondria respiration ability than norepinephrine.These fi ndings suggest that ginsenoside F1 is a promising lead compound in the improvement of insulin resistance.
基金supported by the National Natural Science Foundation of China [31701598]the National Natural Science Foundation of China [31371760]the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Objective We aimed to explore how fermented barley extracts with Lactobacillus plantarum dy-1(LFBE) affected the browning in adipocytes and obese rats.Methods In vitro, 3T3-L1 cells were induced by LFBE, raw barley extraction(RBE) and polyphenol compounds(PC) from LFBE to evaluate the adipocyte differentiation.In vivo, obese SD rats induced by high fat diet(HFD) were randomly divided into three groups treated with oral gavage:(a) normal control diet with distilled water,(b) HFD with distilled water,(c) HFD with 800 mg LFBE/kg body weight(bw).Results In vitro, LFBE and the PC in the extraction significantly inhibited adipogenesis and potentiated browning of 3T3-L1 preadipocytes, rather than RBE.In vivo, we observed remarkable decreases in the body weight, serum lipid levels, white adipose tissue(WAT) weights and cell sizes of brown adipose tissues(BAT) in the LFBE group after 10 weeks.LFBE group could gain more mass of interscapular BAT(IBAT) and promote the dehydrogenase activity in the mitochondria.And LFBE may potentiate process of the IBAT thermogenesis and epididymis adipose tissue(EAT) browning via activating the uncoupling protein 1(UCP1)-dependent mechanism to suppress the obesity.Conclusion These results demonstrated that LFBE decreased obesity partly by increasing the BAT mass and the energy expenditure by activating BAT thermogenesis and WAT browning in a UCP1-dependent mechanism.
基金Supported by the National Science Foundation of China, No. 30271130
文摘AIM： To observe the relationship between ethanol-induced oxidative damage in human primary cultured hepatocytes and cytochrome P450 2E1 （CYP2E1） activity, in order to address if inhibition of CYP2E1 could attenuate ethanol- induced cellular damage. METHODS： The dose-dependent （25-100 mmol/L） and time-dependent （0-24 h） exposures of primary human cultured hepatocytes to ethanol were carried out. CYP2E1 activity and protein expression were detected by spectrophotometer and Western blot analysis respectively. Hepatotoxicity was investigated by determination of lactate dehydrogenase （LDH） and aspartate transaminase （AST） level in hepatocyte culture supernatants, as well as the intracellular formation of malondialdehyde （MDA）. RESULTS： A dose-and time-dependent response between ethanol exposure and CYP2E1 activity in human hepatocytes was demonstrated. Moreover, there was a time-dependent increase of CYP2E1 protein after 100 mmol/L ethanol exposure. Meanwhile, ethanol exposure of hepatocytes caused a time-dependent increase of cellular MDA level, LDH, and AST activities in supernatants. Furthermore, the inhibitor of CYP2E1, diallyl sulfide （DAS） could partly attenuate the increases of MDA, LDH, and AST in human hepatocytes. CONCLUSION： A positive relationship between ethanolinduced oxidative damage in human primary cultured hepatocytes and CYP2E1 activity was exhibited, and the inhibition of CYP2E1 could partly attenuate ethanol-induced oxidative damage.
基金Supported by National Key R&D Program of China,No.2017YFC0908903National Natural Science Foundation of China,No.81873565,No.81470840,and No.81700503.
文摘BACKGROUND Folic acid has been shown to improve non-alcoholic steatohepatitis(NASH),but its roles in hepatic lipid metabolism,hepatic one-carbon metabolism,and gut microbiota are still unknown.AIM To demonstrate the role of folic acid in lipid metabolism and gut microbiota in NASH.METHODS Twenty-four Sprague-Dawley rats were assigned into three groups:Chow diet,high-fat diet(HFD),and HFD with folic acid administration.At the end of 16 wk,the liver histology,the expression of hepatic genes related to lipid metabolism,one-carbon metabolism,and gut microbiota structure analysis of fecal samples based on 16 S r RNA sequencing were measured to evaluate the effect of folic acid.Palmitic acid-exposed Huh7 cell line was used to evaluate the role of folic acid in hepatic lipid metabolism.RESULTS Folic acid treatment attenuated steatosis,lobular inflammation,and hepatocellular ballooning in rats with HFD-induced steatohepatitis.Genes related to lipid de novo lipogenesis,β-oxidation,and lipid uptake were improvedin HFD-fed folic acid-treated rats.Furthermore,peroxisome proliferator-activated receptor alpha(PPARα)and silence information regulation factor 1(SIRT1)were restored by folic acid in HFD-fed rats and palmitic acid-exposed Huh7 cell line.The restoration of PPARαby folic acid was blocked after transfection with SIRT1 si RNA in the Huh7 cell line.Additionally,folic acid administration ameliorated depleted hepatic one-carbon metabolism and restored the diversity of the gut microbiota in rats with HFD-induced steatohepatitis.CONCLUSION Folic acid improves hepatic lipid metabolism by upregulating PPARαlevels via a SIRT1-dependent mechanism and restores hepatic one-carbon metabolism and diversity of gut microbiota,thereby attenuating HFD-induced NASH in rats.
基金supported by grants from the National Key Research and Development Program of China (2017YFA0104600)the National Natural Science Foundation of China (31970767, 31771597 and 31571515)+1 种基金the National Basic Research Program of China (973 Program 2012CB966601 and 2013CB945300)the Ministry of Science and Technology of the People’s Republic of China (2011DFB30010)。
文摘Cyclin-dependent kinase 1 (CDK1) plays an essential role in cell cycle regulation.However,as mouse Cdk1embryos die early,the role of CDK1 in regulating the cell cycle and embryo development remains unclear.Here,we showed that zebrafish cdk1^(-/-)embryos exhibit severe microphthalmia accompanied by multiple defects in S phase entry,M phase progression,and cell differentiation but not in interkinetic nuclear migration.We identified Top2a as a potential downstream target and cyclin A2 and cyclin B1 as partners of Cdk1 in cell cycle regulation via an in silico analysis.While depletion of either cyclin A2 or Top2a led to the decreased S phase entry in zebrafish retinal cells,the depletion of cyclin B1 led to M phase arrest.Moreover,phosphorylation of Top2a at serine 1213 (S1213) was nearly abolished in both cdk1 and ccna2mutants,but not in ccnb1 mutants.Furthermore,overexpression of TOP2A^(S1213D),the phosphomimetic form of human TOP2A,rescued S phase entry and alleviated the microphthalmia defects in both cdk1^(-/-)and ccna2^(-/-)embryos.Taken together,our data suggest that Cdk1 interacts with cyclin A2 to regulate S phase entry partially through Top2a phosphorylation and interacts with cyclin B1 to regulate M phase progression.
基金This work was supported by the National Natural Science Foundation of China(No.81627802)the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.PAPD2014-2016)the National Key R&D Program of China(No.2019YFA0210100).
文摘Objective:Cardiac hypertrophy and fibrosis are major pathological manifestations observed in left ventricular remodeling induced by angiotensin II(AngII).Low-intensity pulsed ultrasound(LIPUS)has been reported to ameliorate cardiac dysfunction and myocardial fibrosis in myocardial infarction(MI)through mechano-transduction and its downstream pathways.In this study,we aimed to investigate whether LIPUS could exert a protective effect by ameliorating AngII-induced cardiac hypertrophy and fibrosis and if so,to further elucidate the underlying molecular mechanisms.Methods:We used AngII to mimic animal and cell culture models of cardiac hypertrophy and fibrosis.LIPUS irradiation was applied in vivo for 20 min every 2 d from one week before mini-pump implantation to four weeks after mini-pump implantation,and in vitro for 20 min on each of two occasions 6 h apart.Cardiac hypertrophy and fibrosis levels were then evaluated by echocardiographic,histopathological,and molecular biological methods.Results:Our results showed that LIPUS could ameliorate left ventricular remodeling in vivo and cardiac fibrosis in vitro by reducing AngII-induced release of inflammatory cytokines,but the protective effects on cardiac hypertrophy were limited in vitro.Given that LIPUS increased the expression of caveolin-1 in response to mechanical stimulation,we inhibited caveolin-1 activity with pyrazolopyrimidine 2(pp2)in vivo and in vitro.LIPUS-induced downregulation of inflammation was reversed and the anti-fibrotic effects of LIPUS were absent.Conclusions:These results indicated that LIPUS could ameliorate AngII-induced cardiac fibrosis by alleviating inflammation via a caveolin-1-dependent pathway,providing new insights for the development of novel therapeutic apparatus in clinical practice.
基金supported by Agriculture and Food Research Initiative Competitive(Grant no.2015–67,015-23,231)from the USDA National Institute of Food and Agricultureseed funding from the Food for the twenty-first Century program of the University of Missouri to P.S.Work in Y-J.Y.+6 种基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2013R1A6A3A04063769)M.K.and J.N.was supported by Charles University(PROGRES Q-39)the National Sustainability Program I(NPU I)NrLO1503 provided by the Ministry of Education,Youth and Sports of the Czech RepublicK.A.,T.Z.,K.H.,J.P.and J.N.were supported by the National Agency of Agriculture Sciences(NAZV QJ1510138)the Czech Ministry of Agriculture(MZe RO 0714)
文摘Background: The histone code is an established epigenetic regulator of early embryonic development in mammals.The lysine residue K9 of histone H3(H3 K9) is a prime target of SIRT1, a member of NAD+-dependent histone deacetylase family of enzymes targeting both histone and non-histone substrates. At present, little is known about SIRT1-modulation of H3 K9 in zygotic pronuclei and its association with the success of preimplantation embryo development. Therefore, we evaluated the effect of SIRT1 activity on H3 K9 methylation and acetylation in porcine zygotes and the significance of H3 K9 modifications for early embryonic development.Results: Our results show that SIRT1 activators resveratrol and BML-278 increased H3 K9 methylation and suppressed H3 K9 acetylation in both the paternal and maternal pronucleus. Inversely, SIRT1 inhibitors nicotinamide and sirtinol suppressed methylation and increased acetylation of pronuclear H3 K9. Evaluation of early embryonic development confirmed positive effect of selective SIRT1 activation on blastocyst formation rate(5.2 ± 2.9% versus 32.9 ± 8.1% in vehicle control and BML-278 group, respectively; P ≤ 0.05). Stimulation of SIRT1 activity coincided with fluorometric signal intensity of ooplasmic ubiquitin ligase MDM2, a known substrate of SIRT1 and known limiting factor of epigenome remodeling.Conclusions: We conclude that SIRT1 modulates zygotic histone code, obviously through direct deacetylation and via non-histone targets resulting in increased H3 K9 me3. These changes in zygotes lead to more successful pre-implantation embryonic development and, indeed, the specific SIRT1 activation due to BML-278 is beneficial for in vitro embryo production and blastocyst achievement.
基金Supported by Medical and Health Science and Technology Project of Zhejiang Province(No.2023KY1356).
文摘AIM:To evaluate the effects of LIN28A(human)on high glucose-induced retinal pigmented epithelium(RPE)cell injury and its possible mechanism.METHODS:Diabetic retinopathy model was generated following 48h of exposure to 30 mmol/L high glucose(HG)in ARPE-19 cells.Quantitative real-time polymerase chain reaction(qRT-PCR)and Western blot tested the expression of the corresponding genes and proteins.Cell viability as well as apoptosis was determined through cell counting kit-8(CCK-8)and flow cytometry assays.Immunofluorescence assay was adopted to evaluate autophagy activity.Caspase 3 activity,oxidative stress markers,and cytokines were appraised adopting their commercial kits,respectively.Finally,ARPE-19 cells were preincubated with EX527,a Sirtuin 1(SIRT1)inhibitor,prior to HG stimulation to validate the regulatory mechanism.RESULTS:LIN28A was downregulated in HG-challenged ARPE-19 cells.LIN28A overexpression greatly inhibited HGinduced ARPE-19 cell viability loss,apoptosis,oxidative damage as well as inflammatory response.Meanwhile,the repressed autophagy and SIRT1 in ARPE-19 cells challenged with HG were elevated after LIN28A overexpression.In addition,treatment of EX527 greatly inhibited the activated autophagy following LIN28A overexpression and partly abolished the protective role of LIN28A against HG-elicited apoptosis,oxidative damage as well as inflammation in ARPE-19 cells.CONCLUSION:LIN28A exerts a protective role against HG-elicited RPE oxidative damage,inflammation,as well as apoptosis via regulating SIRT1/autophagy.
文摘Oral mucosal inflammatory responses to P. gingivalis and its key virulence factor, lipopolysaccharide (LPS), are characterized by a massive rise in proinflammatory cytokine production, up-regu- lation in mitogen-activated protein kinase (MAPK) cascade, and the induction in epidermal growth factor receptor (EGFR) activation. In this study, we report that stimulation of salivary gland acinar cells with P. gingivalis LPS leads to p38 MAPK-dependent release of soluble TGF-α ligand and the increase in EGFR phosphorylation. Further, we show that the LPS-induced TGF-α shedding and EGFR transactivation involve the activation of membrane-associated metalloprotease, TACE also known as ADAM17, through phosphorylation by p38 MAPK, and require Rac1 participation. Moreover, we demonstrate that blocking the Rac1 activation leads to the suppression in the membrane translocation of Rac1 as well as p38, thus indicating that the LPS-elicited p38 membrane recruitment for TACE phosphorylation requires colocalization with Rac1. Hence, our findings imply that Rac1 membrane translocation serves as an essential platform for the localization of p38 with TACE, TGF-α ectodomain shedding, and the EGFR activation.
基金Supported by The National Natural Science Foundation of China,No.30270532 and No.30670774Tsinghua-Yue-Yuen Medical Science Foundation,No.20240000531 and No.20240000547
文摘AIM： To explore the possibility of using the Noninvasive Micro-test Technique （NMT） to investigate the role of Transient Receptor Potential Canonical 1 （TRPC1） in regulating Ca^2＋ influxes in HL-7702 cells, a normal human liver cell line.METHODS： Net Ca^2＋ fluxes were measured with NMT, a technology that can obtain dynamic information of specific/selective ionic/molecular activities on material surfaces, non-invasively. The expression levels of TRPCl were increased by liposomal transfection, whose effectiveness was evaluated by Western-blotting and single cell reverse transcription-polymerase chain reaction.RESULTS： Ca^2＋ influxes could be elicited by adding 1 mmol/L CaCl2 to the test solution of HL-7702 cells. They were enhanced by addition of 20 μmol/L noradrenalin and inhibited by 100 μmol/L LaCl3 （a non-selective Ca^2＋ channel blocker）; 5 μmol/L nifedipine did not induce any change. Overexpression of TRPCl caused increased Ca^2＋ influx. Five micromoles per liter nifedipine did not inhibit this elevation, whereas 100 μmol/L LaCI3 did.CONCLUSION： In HL-7702 cells, there is a type of TRPCl-dependent Ca^2＋ channel, which could be detected v/a NMT and inhibited by La^3＋.
