Sekeres et al. （1） conducted a multicenter randomized, controlled trial to compare whether azacitidine-based combinations with lenalidomide or vorinostat produce superior overall response rates to azacitidine in the...Sekeres et al. （1） conducted a multicenter randomized, controlled trial to compare whether azacitidine-based combinations with lenalidomide or vorinostat produce superior overall response rates to azacitidine in the treatment of myelodysplastic syndromes （MDS）. In that trial, 224 patients with higher-risk MDS and 53 with chronic myelomonocytic leukemia （CMML） were enrolled and randomly assigned to the ＂azacitidine＂ group, ＂azacitidine plus lenalidomide＂ group or ＂azacitidine plus vorinostat＂ group. The researchers found that patients with MDS treated with azacitidine-based combinations had similar response rate to azacitidine monotherapy. Using genomic mutation analysis, they found that the overall response rate to azacitidine-based treatment was higher for patients with mutations in DNMT3A and lower for those with mutations in SRSF2. Whereas in another study, Welch et al. enrolled 26 patients with MDS and 90 with acute myeloid leukemia （AML） who were treated with decitabine, and they found that patients with TP53 mutations had a higher response rate, but not those with DNMT3A mutations （2）. We propose that this big discrepancy in the conclusions between the two studies might have been caused by the presence of many co-interacting factors, e.g. study aims, DNA demethylating agents, treatment protocols, and patient sources.展开更多
L-Theanine(LTA)is a non-protein amino acid mainly found in tea plants with many beneficial effects.Exercise exerts a wide range of benefits in metabolic health.Here,we show that exercise or gastric lavage intervention...L-Theanine(LTA)is a non-protein amino acid mainly found in tea plants with many beneficial effects.Exercise exerts a wide range of benefits in metabolic health.Here,we show that exercise or gastric lavage intervention on mice with LTA improves diet-induced nonalcoholic steatohepatitis(NASH)in mice.Meanwhile,combinatory therapy shows that exercise and LTA synergistically improve obesity-related metabolic disorders and NASH phenotypes,including hepatic steatosis,inflammation,cell death and oxidative stress.In vivo studies indicate that LTA inhibits free fatty acid(FFA)-induced hepatocyte injury,including steatosis,oxidative stress and apoptosis.Knockdown of Nrf2 blunts the role of LTA in inhibiting FFA-induced hepatocyte oxidative stress and dysfunction.Mechanistically,LTA increases theα-ketoglutarate(α-KG)level in hepatocytes,which increases the transcription of Nrf2 by inducing active DNA demethylation on its promoter.Moreover,LTA promote the aboveα-KG/Nrf2 axis in synergy with exercise,thereby more efficiently inhibiting hepatic oxidative stress and ameliorating diet-induced NASH in mice.Our results suggest that,through promoting theα-KG/Nrf2 axis-mediated anti-oxidative pathway,the combination of LTA and exercise may provide an effective measure for the prevention and control of NASH.展开更多
Microorganisms play a critical role in the biotransformation of arsenic and the form which it exists in the environment. In this study, a methyl parathion-degrading bacterium Caballeronia jiangsuensis, isolated from a...Microorganisms play a critical role in the biotransformation of arsenic and the form which it exists in the environment. In this study, a methyl parathion-degrading bacterium Caballeronia jiangsuensis, isolated from an abandoned pesticide manufacturing plant, was used to analyze arsenic accumulation and transformation. The accumulation of trivalent organoarsenic compounds in C. jiangsuensis occurred to a greater extent than that of their pentavalent counterparts. The chromosome of C. jiangsuensis contains an arsenic gene island whose GC content is significantly lower than that of the genome, suggesting that the island was acquired via horizontal gene transfer. There was approximately 90%-99% similarity between the proteins encoded by the gene island and the corresponding sequence of the plasmid pkk5 from Burkholderia sp. KK1. The biotransformation of different arsenic species by C. jiangsuensis was subsequently analyzed. The results revealed that monomethylarsenic acid(MAs(Ⅴ)) was rapidly demethylated to arsenate with very small amounts of intermediate monomethylarsonous acid(MAs(Ⅲ)), whereas MAs(Ⅲ) was largely oxidized to MAs(Ⅴ) despite the occurrence of the gene arsI probably responsible for aerobic demethylation of MAs(Ⅲ) in C. jiangsuensis. In addition, dimethylarsenic acid was partly demethylated to arsenate. Horizontal gene transfer of ars operon from a plasmid to other bacteria represents an adaptation to a specific environment. This study provides a new perspective for understanding arsenic biogeochemical cycling.展开更多
Carbon black(CB)is a vital constituent of airborne pollutants,comprising diesel exhaust and fine particulate matter(PM_(2.5)),aswell as a prevalent manufacturingmaterial.CBwas known to cause pulmonary dysfunction and ...Carbon black(CB)is a vital constituent of airborne pollutants,comprising diesel exhaust and fine particulate matter(PM_(2.5)),aswell as a prevalent manufacturingmaterial.CBwas known to cause pulmonary dysfunction and fibrosis.However,the detailedmolecular mechanisms underlying fibrosis development are poorly understood.In this study,18 C57BL/6mice were randomized into two groups and exposed to CB and filtered air(FA)for 28 days,with 6 hr/day and 7 days perweek exposure regimen,respectively.The human normal bronchial epithelial cell line(BEAS-2B)was subjected to CB treatment for 24 h in vitro,with CB concentrations in 0,50,100,and 200μg/mL.Our study indicated that exposure to CB resulted in a reduction in lung function and the development of pulmonary fibrosis in mice.Furthermore,our results showed cytoskeleton rearrangement and epithelial-mesenchymal transition(EMT)phenotype in BEAS-2B cells were happened,after CB exposure.Subsequent studies revealed that elevated expression of THBS2 after CB primarily contributed to the development of pulmonary fibrosis.The research findings from both in vivo and in vitro studies provided evidence that piR-713551 was involved in CB exposure-induced EMT by targeting the THBS2 gene and activating theβ-catenin pathway.Mechanically,piR-713551/PIWIL4 complex activated the THBS2 transcription by recruitment of histone demethyltransferase KDM4A to reduce H3K9me3 modification at the THBS2 gene promoter.Conclusively,our research showed that CB exposure could activate EMT and lead pulmonary fibrosis which was modulated by piR-713551/PIWIL4 targeting THBS2.展开更多
In the mammalian genome,most CpGs are methylated.However,CpGs within the CpG islands(CGIs)are largely unmethylated,which are important for gene expression regulation.The mechanism underlying the low methylation levels...In the mammalian genome,most CpGs are methylated.However,CpGs within the CpG islands(CGIs)are largely unmethylated,which are important for gene expression regulation.The mechanism underlying the low methylation levels at CGIs remains largely elusive.KDM2 proteins(KDM2A and KDM2B)are H3K36me2 demethylases known to bind specifically at CGIs.Here,we report that depletion of each or both KDM2 proteins,or mutation of all their JmjC domains that harbor the H3K36me2 demethylation activity,leads to an increase in DNA methylation at selective CGIs.The Kdm2a/2b double knockout shows a stronger increase in DNA methylation compared with the single mutant of Kdm2a or Kdm2b,indicating that KDM2A and KDM2B redundantly regulate DNA methylation at CGIs.In addition,the increase of CGI DNA methylation upon mutations of KDM2 proteins is associated with the chromatin environment.Our findings reveal that KDM2A and KDM2B function redundantly in regulating DNA methylation at a subset of CGIs in an H3K36me2 demethylation-dependent manner.展开更多
BACKGROUND Cardiovascular diseases are the major cause of mortality worldwide.Regeneration of the damaged myocardium remains a challenge due to mechanical constraints and limited healing ability of the adult heart tis...BACKGROUND Cardiovascular diseases are the major cause of mortality worldwide.Regeneration of the damaged myocardium remains a challenge due to mechanical constraints and limited healing ability of the adult heart tissue.Cardiac tissue engineering using biomaterial scaffolds combined with stem cells and bioactive molecules could be a highly promising approach for cardiac repair.Use of biomaterials can provide suitable microenvironment to the cells and can solve cell engraftment problems associated with cell transplantation alone.Mesenchymal stem cells(MSCs)are potential candidates in cardiac tissue engineering because of their multilineage differentiation potential and ease of isolation.Use of DNA methyl transferase inhibitor,such as zebularine,in combination with three-dimensional(3D)scaffold can promote efficient MSC differentiation into cardiac lineage,as epigenetic modifications play a fundamental role in determining cell fate and lineage specific gene expression.AIM To investigate the role of collagen scaffold and zebularine in the differentiation of rat bone marrow(BM)-MSCs and their subsequent in vivo effects.METHODS MSCs were isolated from rat BM and characterized morphologically,immunophenotypically and by multilineage differentiation potential.MSCs were seeded in collagen scaffold and treated with 3μmol/L zebularine in three different ways.Cytotoxicity analysis was done and cardiac differentiation was analyzed at the gene and protein levels.Treated and untreated MSC-seeded scaffolds were transplanted in the rat myocardial infarction(MI)model and cardiac function was assessed by echocardiography.Cell tracking was performed by DiI dye labeling,while regeneration and neovascularization were evaluated by histological and immunohistochemical analysis,respectively.RESULTS MSCs were successfully isolated and seeded in collagen scaffold.Cytotoxicity analysis revealed that zebularine was not cytotoxic in any of the treatment groups.Cardiac differentiation analysis showed more pronounced results in the type 3 treatment group which was subsequently chosen for the transplantation in the in vivo MI model.Significant improvement in cardiac function was observed in the zebularine treated MSC-seeded scaffold group as compared to the MI control.Histological analysis also showed reduction in fibrotic scar,improvement in left ventricular wall thickness and preservation of ventricular remodeling in the zebularine treated MSC-seeded scaffold group.Immunohistochemical analysis revealed significant expression of cardiac proteins in DiI labeled transplanted cells and a significant increase in the number of blood vessels in the zebularine treated MSC-seeded collagen scaffold transplanted group.CONCLUSION Combination of 3D collagen scaffold and zebularine treatment enhances cardiac differentiation potential of MSCs,improves cell engraftment at the infarcted region,reduces infarct size and improves cardiac function.展开更多
Objective: To investigate the therapeutic effect of applying venetoclax combined with demethylating drugs in treating patients with acute myeloid leukemia (AML). Methods: Eighty cases of AML patients treated with vene...Objective: To investigate the therapeutic effect of applying venetoclax combined with demethylating drugs in treating patients with acute myeloid leukemia (AML). Methods: Eighty cases of AML patients treated with venetoclax combined with demethylating drugs in our hospital were selected from March 2021 to March 2024, including 40 cases of primary treatment patients and 40 cases of relapsed and refractory patients. The efficacy and safety of the combined drug therapy was analyzed. Results: The primary treatment group was presented with a complete remission (CR) rate of 40.5%, partial remission (PR) rate of 47.50%, no response (NR) rate of 12.50%, and a remission rate of 87.50%. The relapsed- refractory group was presented with a CR rate of 37.50%, PR rate of 42.50%, NR rate of 17.50%, and a remission rate of 87.50%. There was no statistical significance between the groups (P > 0.05). The hematological adverse reactions of the combined treatment for AML were leukopenia and the non-hematological adverse reactions were mainly infections, with an incidence rate of 87.50%. Conclusion: The efficacy of venetoclax combined with demethylating drugs in AML was remarkable and the treatment regimen can be adjusted according to the treatment-resistant response.展开更多
Human dental pulp cells （hDPCs） possess the capacity to differentiate into odontoblast-like cells and generate reparative dentin in response to exogenous stimuli or injury. Ten-eleven translocation 1 （TET1） is a n...Human dental pulp cells （hDPCs） possess the capacity to differentiate into odontoblast-like cells and generate reparative dentin in response to exogenous stimuli or injury. Ten-eleven translocation 1 （TET1） is a novel DNA methyldioxygenase that plays an important role in the promotion of DNA demethylation and transcriptional regulation in several cell lines. However, the role of TET1 in the biological functions of hDPCs is unknown. To investigate the effect of TET1 on the proliferation and odontogenic differentiation potential of hDPCs, a recombinant shRNA lentiviral vector was used to knock down TET1 expression in hDPCs. Following TET1 knockdown, TET1 was significantly downregulated at both the mRNA and protein levels. Proliferation of the hDPCs was suppressed in the TET1 knockdown groups. Alkaline phosphatase activity, the formation of mineralized nodules, and the expression levels of DSPP and DMP1 were all reduced in the TETl-knockdown hDPCs undergoing odontogenic differentiation. Based on these results, we concluded that TET1 knockdown can prevent the proliferation and odontogenic differentiation of hDPCs, which suggests that TET1 may play an important role in dental pulp repair and regeneration.展开更多
Berberine(BBR)is an isoquinoline alkaloid extracted from Coptis chinensis that improves diabetes,hyperlipidemia and inflammation.Due to the low oral bioavailability of BBR,its mechanism of action is closely related to...Berberine(BBR)is an isoquinoline alkaloid extracted from Coptis chinensis that improves diabetes,hyperlipidemia and inflammation.Due to the low oral bioavailability of BBR,its mechanism of action is closely related to the gut microbiota.This study focused on the CYP51 enzyme of intestinal bacteria to elucidate a new mechanism of BBR transformation by demethylation in the gut microbiota through multiple analytical techniques.First,the docking of BBR and CYP51 was performed;then,the pharmacokinetics of BBR was determined in ICR mice in vivo,and the metabolism of BBR in the liver,kidney,gut microbiota and single bacterial strains was examined in vitro.Moreover,16S rRNA analysis of ICR mouse feces indicated the relationship between BBR and the gut microbiota.Finally,recombinant E.coli containing cyp51 gene was constructed and the CYP51 enzyme lysate was induced to express.The metabolic characteristics of BBR were analyzed in the CYP51 enzyme lysate system.The results showed that CYP51 in the gut microbiota could bind stably with BBR,and the addition of voriconazole(a specific inhibitor of CYP51)slowed down the metabolism of BBR,which prevented the production of the demethylated metabolites thalifendine and berberrubine.This study demonstrated that CYP51 promoted the demethylation of BBR and enhanced its intestinal absorption,providing a new method for studying the metabolic transformation mechanism of isoquinoline alkaloids in vivo.展开更多
Pancreatic cancer(PC)is an aggressive human cancer.Appropriate methods for the diagnosis and treatment of PC have not been found at the genetic level,thus making epigenetics a promising research path in studies of PC....Pancreatic cancer(PC)is an aggressive human cancer.Appropriate methods for the diagnosis and treatment of PC have not been found at the genetic level,thus making epigenetics a promising research path in studies of PC.Histone methylation is one of the most complicated types of epigenetic modifications and has proved crucial in the development of PC.Histone methylation is a reversible process regulated by readers,writers,and erasers.Some writers and erasers can be recognized as potential biomarkers and candidate therapeutic targets in PC because of their unusual expression in PC cells compared with normal pancreatic cells.Based on the impact that writers have on the development of PC,some inhibitors of writers have been developed.However,few inhibitors of erasers have been developed and put to clinical use.Meanwhile,there is not enough research on the reader domains.Therefore,the study of erasers and readers is still a promising area.This review focuses on the regulatory mechanism of histone methylation,and the diagnosis and chemotherapy of PC based on it.The future of epigenetic modification in PC research is also discussed.展开更多
Brain development and aging are associated with alterations in multiple epigenetic systems, including DNA methylation and demethylation patterns. Here, we observed that the levels of the 5- hydroxymethylcytosine （5hm...Brain development and aging are associated with alterations in multiple epigenetic systems, including DNA methylation and demethylation patterns. Here, we observed that the levels of the 5- hydroxymethylcytosine （5hmC） ten-eleven transtocation （TET） enzyme-mediated active DNA demethylation products were dynamically changed and involved in postnatal brain development and aging in tree shrews （Tupaia belangeri chinensis）. The levels of 5hmC in multiple anatomic structures showed a gradual increase throughout postnatal development, whereas a significant decrease in 5hmC was found in several brain regions in aged tree shrews, including in the prefrontal cortex and hippocampus, but not the cerebellum. Active changes in Tet mRNA levels indicated that TET2 and TET3 predominantly contributed to the changes in 5hmC levels. Our findings provide new insight into the dynamic changes in 5hmC levels in tree shrew brains during postnatal development and aging processes.展开更多
Lignin is a natural biopolymer with a complex three-dimensional network, commercially obtained from wasteliquid of paper pulp and bioethanol production, and could be a candidate for preparation of environment-friendly...Lignin is a natural biopolymer with a complex three-dimensional network, commercially obtained from wasteliquid of paper pulp and bioethanol production, and could be a candidate for preparation of environment-friendlybio-based polyphenol material. In the present work, the demethylated wheat straw alkali lignin (D-Lig), preparedby demethylation of wheat straw alkali lignin (Lig) using an in-situ generated Lewis acid, was used to synthesizebio-based phenol formaldehyde resin adhesive (D-LPF) applied in plywood. Effects of synthetic process’s factors,including lignin substitution for phenol, NaOH concentration and molar ratio of formaldehyde to phenol, on thebonding strength and free formaldehyde content of D-LPF were investigated in detail, and the optimum syntheticprocess of D-LPF was obtained as following: Lignin substitution for phenol 60%, NaOH concentration 5.0% andmolar ratio of formaldehyde to phenol 2.0, and under the optimum reaction condition, the D-LPF presented lower free formaldehyde content (0.18%) and higher bonding strength (2.19 MPa), which was better than those ofcontaining-lignin phenol formaldehyde resin adhesive (LPF). Additionally, the curing behavior of the adhesivewas studied by differential scanning calorimetry (DSC) combined with gel time. It can be obtained that D-LPFresin adhesive had the shortest gel time, and fastest curing rate, compared with those of PF and L-PF resin adhesives. The curing kinetics data was fitted well by Kissinger model using non-isothermal DSC method, and theaverage activation energy value was 85.3 kJ/mol, slightly higher than that of commercial PF resin, while lowerthan that of LPF (90.2 kJ/mol). Finally, based on the analytical results of high temperature fourier transform infrared spectroscopy (FTIR), a possible curing mechanism of D-LPF was proposed.展开更多
BACKGROUND The expression of the membrane receptor protein GFRA1 is frequently upregulated in many cancers,which can promote cancer development by activating the classic RET-RAS-ERK and RET-RAS-PI3K-AKT pathways.Sever...BACKGROUND The expression of the membrane receptor protein GFRA1 is frequently upregulated in many cancers,which can promote cancer development by activating the classic RET-RAS-ERK and RET-RAS-PI3K-AKT pathways.Several therapeutic anti-GFRA1 antibody-drug conjugates are under development.Demethylation(or hypomethylation)of GFRA1 CpG islands(dmGFRA1)is associated with increased gene expression and metastasis risk of gastric cancer.However,it is unknown whether dmGFRA1 affects the metastasis of other cancers,including colon cancer(CC).AIM To study whether dmGFRA1 is a driver for CC metastasis and GFRA1 is a potential therapeutic target.METHODS CC and paired surgical margin tissue samples from 144 inpatients and normal colon mucosal biopsies from 21 noncancer patients were included in this study.The methylation status of GFRA1 islands was determined by MethyLight and denaturing high-performance liquid chromatography and bisulfite-sequencing.Kaplan-Meier analysis was used to explore the effect of dmGFRA1 on the survival of CC patients.Impacts of GFRA1 on CC cell proliferation and migration were evaluated by a battery of biological assays in vitro and in vivo.The phosphorylation of AKT and ERK proteins was examined by Western blot analysis.RESULTS The proportion of dmGFRA1 in CC,surgical margin,and normal colon tissues by MethyLight was 68.4%,73.4%,and 35.9%(median;nonparametric test,P=0.001 and<0.001),respectively.Using the median value of dmGFRA1 peak area proportion as the cutoff,the proportion of dmGFRA1-high samples was much higher in poorly differentiated CC samples than in moderately or welldifferentiated samples(92.3%%vs 55.8%,Chi-square test,P=0.002)and significantly higher in CC samples with distant metastasis than in samples without(77.8%vs 46.0%,P=0.021).The overall survival of patients with dmGFRA1-low CC was significantly longer than that of patients with dmGFRA1-high CC(adjusted hazard ratio=0.49,95%confidence interval:0.24-0.98),especially for 89 CC patients with metastatic CC(adjusted hazard ratio=0.41,95%confidence interval:0.18-0.91).These data were confirmed by the mining results from TCGA datasets.Furthermore,GFRA1 overexpression significantly promoted the proliferation/invasion of RKO and HCT116 cells and the growth of RKO cells in nude mice but did not affect their migration.GFRA1 overexpression markedly increased the phosphorylation levels of AKT and ERK proteins,two key molecules in two classic GFRA1 downstream pathways.CONCLUSION GFRA1 expression is frequently reactivated by DNA demethylation in CC tissues and is significantly associated with a poor prognosis in patients with CC,especially those with metastatic CC.GFRA1 can promote the proliferation/growth of CC cells,probably by the activation of AKT and ERK pathways.GFRA1 might be a therapeutic target for CC patients,especially those with metastatic potential.展开更多
Mesenchymal stem cells(MSCs)are a heterogeneous population that can be isolated from various tissues,including bone marrow,adipose tissue,umbilical cord blood,and craniofacial tissue.MSCs have attracted increasingly m...Mesenchymal stem cells(MSCs)are a heterogeneous population that can be isolated from various tissues,including bone marrow,adipose tissue,umbilical cord blood,and craniofacial tissue.MSCs have attracted increasingly more attention over the years due to their regenerative capacity and function in immunomodulation.The foundation of tissue regeneration is the potential of cells to differentiate into multiple cell lineages and give rise to multiple tissue types.In addition,the immunoregulatory function of MSCs has provided insights into therapeutic treatments for immune-mediated diseases.DNA methylation and demethylation are important epigenetic mechanisms that have been shown to modulate embryonic stem cell maintenance,proliferation,differentiation and apoptosis by activating or suppressing a number of genes.In most studies,DNA hypermethylation is associated with gene suppression,while hypomethylation or demethylation is associated with gene activation.The dynamic balance of DNA methylation and demethylation is required for normal mammalian development and inhibits the onset of abnormal phenotypes.However,the exact role of DNA methylation and demethylation in MSC-based tissue regeneration and immunomodulation requires further investigation.In this review,we discuss how DNA methylation and demethylation function in multi-lineage cell differentiation and immunomodulation of MSCs based on previously published work.Furthermore,we discuss the implications of the role of DNA methylation and demethylation in MSCs for the treatment of metabolic or immune-related diseases.展开更多
Cytosine methylation/demethylation plays pivotal roles in regulating gene expression at a genome-wide level. However, limited reports are available to reveal correlating changes of cytosine methylation and proteomic e...Cytosine methylation/demethylation plays pivotal roles in regulating gene expression at a genome-wide level. However, limited reports are available to reveal correlating changes of cytosine methylation and proteomic expression in Brassica napus so far. Therefore, in the present study, global cytosine methylation and proteome were analysed in B. napus after cold treatment by methylation-sensitive amplified polymorphism （MSAP） and two-dimensional protein electrophoresis technology （2-DE）. The results showed that the lowered genome-wide DNA methylation status was revealed after cold treatment, and about 0.88% of discrepancy in DNA methylation was detected between the non-flowering and flowering plants after cold treatment. Moreover, the 52 significantly up-regulated proteins emerged in comparison with the 36 down-regulated proteins, as well as the 14 proteins exclusively detected in the flowering plants. Intriguingly the 8 specifically expressed proteins in the non-flowering plants disappeared in the flowering plants with cold treatment. Therefore, these present data proved that the correlating changes of cytosine methylation and proteomic expression were evidenced under cold treatment in B. napus.展开更多
Inflammation is closely related to stroke prognosis, and high inflammation status leads to poor functional outcome in stroke. DNA methylation is involved in the pathogenesis and prognosis of stroke. However, the effec...Inflammation is closely related to stroke prognosis, and high inflammation status leads to poor functional outcome in stroke. DNA methylation is involved in the pathogenesis and prognosis of stroke. However, the effect of DNA methylation on stroke at high levels of inflammation is unclear. In this study, we constructed a hyperinflammatory cerebral ischemia mouse model and investigated the effect of hypomethylation and hypermethylation on the functional outcome. We constructed a mouse model of transient middle cerebral artery occlusion and treated the mice with lipopolysaccharide to induce a hyperinflammatory state. To investigate the effect of DNA methylation on stroke, we used small molecule inhibitors to restrain the function of key DNA methylation and demethylation enzymes. 2,3,5-Triphenyltetrazolium chloride staining, neurological function scores, neurobehavioral tests, enzyme-linked immunosorbent assay, quantitative reverse transcription PCR and western blot assay were used to evaluate the effects after stroke in mice. We assessed changes in the global methylation status by measuring DNA 5-mc and DNA 5-hmc levels in peripheral blood after the use of the inhibitor. In the group treated with the DNA methylation inhibitor, brain tissue 2,3,5-triphenyltetrazolium chloride staining showed an increase in infarct volume, which was accompanied by a decrease in neurological scores and worsening of neurobehavioral performance. The levels of inflammatory factors interleukin 6 and interleukin-1 beta in ischemic brain tissue and plasma were elevated, indicating increased inflammation. Related inflammatory pathway exploration showed significant overactivation of nuclear factor kappa B. These results suggested that inhibiting DNA methylation led to poor functional outcome in mice with high inflammation following stroke. Further, the effects were reversed by inhibition of DNA demethylation. Our findings suggest that DNA methylation regulates the inflammatory response in stroke and has an important role in the functional outcome of hyperinflammatory stroke.展开更多
BACKGROUND Inflammatory bowel disease(IBD)constitutes a substantial risk factor for colorectal cancer.Connexin 43(Cx43)is a protein that forms gap junction(GJ)complexes involved in intercellular communication,and its ...BACKGROUND Inflammatory bowel disease(IBD)constitutes a substantial risk factor for colorectal cancer.Connexin 43(Cx43)is a protein that forms gap junction(GJ)complexes involved in intercellular communication,and its expression is altered under pathological conditions,such as IBD and cancer.Recent studies have implicated epigenetic processes modulating DNA methylation in the pathogenesis of diverse inflammatory and malignant diseases.The ten-eleven translocation-2(TET-2)enzyme catalyzes the demethylation,hence,regulating the activity of various cancer-promoting and tumor-suppressor genes.AIM To investigate Cx43 and TET-2 expression levels and presence of 5-hydroxymethylcytosine(5-hmC)marks under inflammatory conditions both in vitro and in vivo.METHODS TET-2 expression was evaluated in parental HT-29 cells and in HT-29 cells expressing low or high levels of Cx43,a putative tumor-suppressor gene whose expression varies in IBD and colorectal cancer,and which has been implicated in the inflammatory process and in tumor onset.The dextran sulfate sodium-induced colitis model was reproduced in BALB/c mice to evaluate the expression of TET-2 and Cx43 under inflammatory conditions in vivo.In addition,archived colon tissue sections from normal,IBD(ulcerative colitis),and sporadic colon adenocarcinoma patients were obtained and evaluated for the expression of TET-2 and Cx43.Expression levels were reported at the transcriptional level by quantitative real-time polymerase chain reaction,and at the translational level by Western blotting and immunofluorescence.RESULTS Under inflammatory conditions,Cx43 and TET-2 expression levels increased compared to noninflammatory conditions.TET-2 upregulation was more pronounced in Cx43-deficient cells.Moreover,colon tissue sections from normal,ulcerative colitis,and sporadic colon adenocarcinoma patients corroborated that Cx43 expression increased in IBD and decreased in adenocarcinoma,compared to tissues from non-IBD subjects.However,TET-2 expression and 5-hmC mark levels decreased in samples from patients with ulcerative colitis or cancer.Cx43 and TET-2 expression levels were also investigated in an experimental colitis mouse model.Interestingly,mice exposed to carbenoxolone(CBX),a GJ inhibitor,had upregulated TET-2 levels.Collectively,these results show that TET-2 levels and activity increased under inflammatory conditions,in cells downregulating gap junctional protein Cx43,and in colon tissues from mice exposed to CBX.CONCLUSION These results suggest that TET-2 expression levels,as well as Cx43 expression levels,are modulated in models of intestinal inflammation.We hypothesize that TET-2 may demethylate genes involved in inflammation and tumorigenesis,such as Cx43,potentially contributing to intestinal inflammation and associated carcinogenesis.展开更多
Synthesis of 11-demethyl and 6, 6, 11-demethyl calanolides A (6-9) have been carried out by a four-step reaction sequence using a simple approach in order to investigate the structural requirements necessary for antiv...Synthesis of 11-demethyl and 6, 6, 11-demethyl calanolides A (6-9) have been carried out by a four-step reaction sequence using a simple approach in order to investigate the structural requirements necessary for antiviral activity.展开更多
Environmental enrichment is known to be beneficial for cognitive improvement.In many animal models of neurological disorders and brain injury,EE has also demonstrated neuroprotective benefits in neurodegenerative dise...Environmental enrichment is known to be beneficial for cognitive improvement.In many animal models of neurological disorders and brain injury,EE has also demonstrated neuroprotective benefits in neurodegenerative diseases and in improving recovery after stroke or traumatic brain injury.The exact underlying mechanism for these phenomena has been unclear.Recent findings have now indicated that neuronal activity elicited by environmental enrichment induces Ca2+influx in dorsal root ganglion neurons results in lasting enhancement of CREB-binding protein-mediated histone acetylation.This,in turn,increases the expression of pro-regeneration genes and promotes axonal regeneration.This mechanism associated with neuronal activity elicited by environmental enrichment-mediated pathway is one of several epigenetic mechanisms which modulate axon regeneration upon injury that has recently come to light.The other prominent mechanisms,albeit not yet directly associated with environmental enrichment,include DNA methylation/demethylation and N6-methyladenosine modification of transcripts.In this brief review,I highlight recent work that has shed light on the epigenetic basis of environmental enrichment-based axon regeneration,and discuss the mechanism and pathways involved.I further speculate on the implications of the findings,in conjunction with the other epigenetic mechanisms,that could be harness to promote axon regeneration upon injury.展开更多
文摘Sekeres et al. （1） conducted a multicenter randomized, controlled trial to compare whether azacitidine-based combinations with lenalidomide or vorinostat produce superior overall response rates to azacitidine in the treatment of myelodysplastic syndromes （MDS）. In that trial, 224 patients with higher-risk MDS and 53 with chronic myelomonocytic leukemia （CMML） were enrolled and randomly assigned to the ＂azacitidine＂ group, ＂azacitidine plus lenalidomide＂ group or ＂azacitidine plus vorinostat＂ group. The researchers found that patients with MDS treated with azacitidine-based combinations had similar response rate to azacitidine monotherapy. Using genomic mutation analysis, they found that the overall response rate to azacitidine-based treatment was higher for patients with mutations in DNMT3A and lower for those with mutations in SRSF2. Whereas in another study, Welch et al. enrolled 26 patients with MDS and 90 with acute myeloid leukemia （AML） who were treated with decitabine, and they found that patients with TP53 mutations had a higher response rate, but not those with DNMT3A mutations （2）. We propose that this big discrepancy in the conclusions between the two studies might have been caused by the presence of many co-interacting factors, e.g. study aims, DNA demethylating agents, treatment protocols, and patient sources.
基金supported by the National Natural Science Foundation of China(82571021,32070751 and 31871435)the Shanghai Natural Science Foundation(25ZR1401328)the Program for Overseas High-level talents at Shanghai Institutions of Higher Learning(TP2022100)。
文摘L-Theanine(LTA)is a non-protein amino acid mainly found in tea plants with many beneficial effects.Exercise exerts a wide range of benefits in metabolic health.Here,we show that exercise or gastric lavage intervention on mice with LTA improves diet-induced nonalcoholic steatohepatitis(NASH)in mice.Meanwhile,combinatory therapy shows that exercise and LTA synergistically improve obesity-related metabolic disorders and NASH phenotypes,including hepatic steatosis,inflammation,cell death and oxidative stress.In vivo studies indicate that LTA inhibits free fatty acid(FFA)-induced hepatocyte injury,including steatosis,oxidative stress and apoptosis.Knockdown of Nrf2 blunts the role of LTA in inhibiting FFA-induced hepatocyte oxidative stress and dysfunction.Mechanistically,LTA increases theα-ketoglutarate(α-KG)level in hepatocytes,which increases the transcription of Nrf2 by inducing active DNA demethylation on its promoter.Moreover,LTA promote the aboveα-KG/Nrf2 axis in synergy with exercise,thereby more efficiently inhibiting hepatic oxidative stress and ameliorating diet-induced NASH in mice.Our results suggest that,through promoting theα-KG/Nrf2 axis-mediated anti-oxidative pathway,the combination of LTA and exercise may provide an effective measure for the prevention and control of NASH.
基金supported by the National Natural Science Foundation of China(Nos.42077289,42277197,and 41877422).
文摘Microorganisms play a critical role in the biotransformation of arsenic and the form which it exists in the environment. In this study, a methyl parathion-degrading bacterium Caballeronia jiangsuensis, isolated from an abandoned pesticide manufacturing plant, was used to analyze arsenic accumulation and transformation. The accumulation of trivalent organoarsenic compounds in C. jiangsuensis occurred to a greater extent than that of their pentavalent counterparts. The chromosome of C. jiangsuensis contains an arsenic gene island whose GC content is significantly lower than that of the genome, suggesting that the island was acquired via horizontal gene transfer. There was approximately 90%-99% similarity between the proteins encoded by the gene island and the corresponding sequence of the plasmid pkk5 from Burkholderia sp. KK1. The biotransformation of different arsenic species by C. jiangsuensis was subsequently analyzed. The results revealed that monomethylarsenic acid(MAs(Ⅴ)) was rapidly demethylated to arsenate with very small amounts of intermediate monomethylarsonous acid(MAs(Ⅲ)), whereas MAs(Ⅲ) was largely oxidized to MAs(Ⅴ) despite the occurrence of the gene arsI probably responsible for aerobic demethylation of MAs(Ⅲ) in C. jiangsuensis. In addition, dimethylarsenic acid was partly demethylated to arsenate. Horizontal gene transfer of ars operon from a plasmid to other bacteria represents an adaptation to a specific environment. This study provides a new perspective for understanding arsenic biogeochemical cycling.
基金supported by the National Natural Science Foundation of China(Nos.81973074,92043202,82204075,and 82204074).
文摘Carbon black(CB)is a vital constituent of airborne pollutants,comprising diesel exhaust and fine particulate matter(PM_(2.5)),aswell as a prevalent manufacturingmaterial.CBwas known to cause pulmonary dysfunction and fibrosis.However,the detailedmolecular mechanisms underlying fibrosis development are poorly understood.In this study,18 C57BL/6mice were randomized into two groups and exposed to CB and filtered air(FA)for 28 days,with 6 hr/day and 7 days perweek exposure regimen,respectively.The human normal bronchial epithelial cell line(BEAS-2B)was subjected to CB treatment for 24 h in vitro,with CB concentrations in 0,50,100,and 200μg/mL.Our study indicated that exposure to CB resulted in a reduction in lung function and the development of pulmonary fibrosis in mice.Furthermore,our results showed cytoskeleton rearrangement and epithelial-mesenchymal transition(EMT)phenotype in BEAS-2B cells were happened,after CB exposure.Subsequent studies revealed that elevated expression of THBS2 after CB primarily contributed to the development of pulmonary fibrosis.The research findings from both in vivo and in vitro studies provided evidence that piR-713551 was involved in CB exposure-induced EMT by targeting the THBS2 gene and activating theβ-catenin pathway.Mechanically,piR-713551/PIWIL4 complex activated the THBS2 transcription by recruitment of histone demethyltransferase KDM4A to reduce H3K9me3 modification at the THBS2 gene promoter.Conclusively,our research showed that CB exposure could activate EMT and lead pulmonary fibrosis which was modulated by piR-713551/PIWIL4 targeting THBS2.
基金supported by the National Natural Science Foundation of China(32070607)the National Key Research and Development Program of China(2020YFA0804000)the CAS Project for Young Scientists in Basic Research(YSBR-012).
文摘In the mammalian genome,most CpGs are methylated.However,CpGs within the CpG islands(CGIs)are largely unmethylated,which are important for gene expression regulation.The mechanism underlying the low methylation levels at CGIs remains largely elusive.KDM2 proteins(KDM2A and KDM2B)are H3K36me2 demethylases known to bind specifically at CGIs.Here,we report that depletion of each or both KDM2 proteins,or mutation of all their JmjC domains that harbor the H3K36me2 demethylation activity,leads to an increase in DNA methylation at selective CGIs.The Kdm2a/2b double knockout shows a stronger increase in DNA methylation compared with the single mutant of Kdm2a or Kdm2b,indicating that KDM2A and KDM2B redundantly regulate DNA methylation at CGIs.In addition,the increase of CGI DNA methylation upon mutations of KDM2 proteins is associated with the chromatin environment.Our findings reveal that KDM2A and KDM2B function redundantly in regulating DNA methylation at a subset of CGIs in an H3K36me2 demethylation-dependent manner.
文摘BACKGROUND Cardiovascular diseases are the major cause of mortality worldwide.Regeneration of the damaged myocardium remains a challenge due to mechanical constraints and limited healing ability of the adult heart tissue.Cardiac tissue engineering using biomaterial scaffolds combined with stem cells and bioactive molecules could be a highly promising approach for cardiac repair.Use of biomaterials can provide suitable microenvironment to the cells and can solve cell engraftment problems associated with cell transplantation alone.Mesenchymal stem cells(MSCs)are potential candidates in cardiac tissue engineering because of their multilineage differentiation potential and ease of isolation.Use of DNA methyl transferase inhibitor,such as zebularine,in combination with three-dimensional(3D)scaffold can promote efficient MSC differentiation into cardiac lineage,as epigenetic modifications play a fundamental role in determining cell fate and lineage specific gene expression.AIM To investigate the role of collagen scaffold and zebularine in the differentiation of rat bone marrow(BM)-MSCs and their subsequent in vivo effects.METHODS MSCs were isolated from rat BM and characterized morphologically,immunophenotypically and by multilineage differentiation potential.MSCs were seeded in collagen scaffold and treated with 3μmol/L zebularine in three different ways.Cytotoxicity analysis was done and cardiac differentiation was analyzed at the gene and protein levels.Treated and untreated MSC-seeded scaffolds were transplanted in the rat myocardial infarction(MI)model and cardiac function was assessed by echocardiography.Cell tracking was performed by DiI dye labeling,while regeneration and neovascularization were evaluated by histological and immunohistochemical analysis,respectively.RESULTS MSCs were successfully isolated and seeded in collagen scaffold.Cytotoxicity analysis revealed that zebularine was not cytotoxic in any of the treatment groups.Cardiac differentiation analysis showed more pronounced results in the type 3 treatment group which was subsequently chosen for the transplantation in the in vivo MI model.Significant improvement in cardiac function was observed in the zebularine treated MSC-seeded scaffold group as compared to the MI control.Histological analysis also showed reduction in fibrotic scar,improvement in left ventricular wall thickness and preservation of ventricular remodeling in the zebularine treated MSC-seeded scaffold group.Immunohistochemical analysis revealed significant expression of cardiac proteins in DiI labeled transplanted cells and a significant increase in the number of blood vessels in the zebularine treated MSC-seeded collagen scaffold transplanted group.CONCLUSION Combination of 3D collagen scaffold and zebularine treatment enhances cardiac differentiation potential of MSCs,improves cell engraftment at the infarcted region,reduces infarct size and improves cardiac function.
文摘Objective: To investigate the therapeutic effect of applying venetoclax combined with demethylating drugs in treating patients with acute myeloid leukemia (AML). Methods: Eighty cases of AML patients treated with venetoclax combined with demethylating drugs in our hospital were selected from March 2021 to March 2024, including 40 cases of primary treatment patients and 40 cases of relapsed and refractory patients. The efficacy and safety of the combined drug therapy was analyzed. Results: The primary treatment group was presented with a complete remission (CR) rate of 40.5%, partial remission (PR) rate of 47.50%, no response (NR) rate of 12.50%, and a remission rate of 87.50%. The relapsed- refractory group was presented with a CR rate of 37.50%, PR rate of 42.50%, NR rate of 17.50%, and a remission rate of 87.50%. There was no statistical significance between the groups (P > 0.05). The hematological adverse reactions of the combined treatment for AML were leukopenia and the non-hematological adverse reactions were mainly infections, with an incidence rate of 87.50%. Conclusion: The efficacy of venetoclax combined with demethylating drugs in AML was remarkable and the treatment regimen can be adjusted according to the treatment-resistant response.
基金supported by the National Nature Science Foundation of China (grant no.81570971)
文摘Human dental pulp cells （hDPCs） possess the capacity to differentiate into odontoblast-like cells and generate reparative dentin in response to exogenous stimuli or injury. Ten-eleven translocation 1 （TET1） is a novel DNA methyldioxygenase that plays an important role in the promotion of DNA demethylation and transcriptional regulation in several cell lines. However, the role of TET1 in the biological functions of hDPCs is unknown. To investigate the effect of TET1 on the proliferation and odontogenic differentiation potential of hDPCs, a recombinant shRNA lentiviral vector was used to knock down TET1 expression in hDPCs. Following TET1 knockdown, TET1 was significantly downregulated at both the mRNA and protein levels. Proliferation of the hDPCs was suppressed in the TET1 knockdown groups. Alkaline phosphatase activity, the formation of mineralized nodules, and the expression levels of DSPP and DMP1 were all reduced in the TETl-knockdown hDPCs undergoing odontogenic differentiation. Based on these results, we concluded that TET1 knockdown can prevent the proliferation and odontogenic differentiation of hDPCs, which suggests that TET1 may play an important role in dental pulp repair and regeneration.
基金The project was supported by CAMS Innovation Fund for Medical Sciences(CIFMS,Grant No.:2016-I2M-3-011,China)the National Natural Science Foundation of China(Grant Nos.:81803613 and 81973290)+2 种基金Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD study(Grant No.:Z141102004414062,China)Beijing Natural Sciences Fund Key Projects(Grant No.:7181007)the National Megaproject for Innovative Drugs(Grant No.:2018ZX09711001-002-002).
文摘Berberine(BBR)is an isoquinoline alkaloid extracted from Coptis chinensis that improves diabetes,hyperlipidemia and inflammation.Due to the low oral bioavailability of BBR,its mechanism of action is closely related to the gut microbiota.This study focused on the CYP51 enzyme of intestinal bacteria to elucidate a new mechanism of BBR transformation by demethylation in the gut microbiota through multiple analytical techniques.First,the docking of BBR and CYP51 was performed;then,the pharmacokinetics of BBR was determined in ICR mice in vivo,and the metabolism of BBR in the liver,kidney,gut microbiota and single bacterial strains was examined in vitro.Moreover,16S rRNA analysis of ICR mouse feces indicated the relationship between BBR and the gut microbiota.Finally,recombinant E.coli containing cyp51 gene was constructed and the CYP51 enzyme lysate was induced to express.The metabolic characteristics of BBR were analyzed in the CYP51 enzyme lysate system.The results showed that CYP51 in the gut microbiota could bind stably with BBR,and the addition of voriconazole(a specific inhibitor of CYP51)slowed down the metabolism of BBR,which prevented the production of the demethylated metabolites thalifendine and berberrubine.This study demonstrated that CYP51 promoted the demethylation of BBR and enhanced its intestinal absorption,providing a new method for studying the metabolic transformation mechanism of isoquinoline alkaloids in vivo.
文摘Pancreatic cancer(PC)is an aggressive human cancer.Appropriate methods for the diagnosis and treatment of PC have not been found at the genetic level,thus making epigenetics a promising research path in studies of PC.Histone methylation is one of the most complicated types of epigenetic modifications and has proved crucial in the development of PC.Histone methylation is a reversible process regulated by readers,writers,and erasers.Some writers and erasers can be recognized as potential biomarkers and candidate therapeutic targets in PC because of their unusual expression in PC cells compared with normal pancreatic cells.Based on the impact that writers have on the development of PC,some inhibitors of writers have been developed.However,few inhibitors of erasers have been developed and put to clinical use.Meanwhile,there is not enough research on the reader domains.Therefore,the study of erasers and readers is still a promising area.This review focuses on the regulatory mechanism of histone methylation,and the diagnosis and chemotherapy of PC based on it.The future of epigenetic modification in PC research is also discussed.
基金supported by the Hundred-Talent Program of Chinese Academy of Sciences(Y4065411411100050210)to J.L.+3 种基金the National Natural Science Foundation of China(8147131391649119)to J.L.the National Natural Science Foundation of China(31260242 to)F.Lthe National Science and Technology Infrastructure Program(2014BAI01B01-04)to S.L.
文摘Brain development and aging are associated with alterations in multiple epigenetic systems, including DNA methylation and demethylation patterns. Here, we observed that the levels of the 5- hydroxymethylcytosine （5hmC） ten-eleven transtocation （TET） enzyme-mediated active DNA demethylation products were dynamically changed and involved in postnatal brain development and aging in tree shrews （Tupaia belangeri chinensis）. The levels of 5hmC in multiple anatomic structures showed a gradual increase throughout postnatal development, whereas a significant decrease in 5hmC was found in several brain regions in aged tree shrews, including in the prefrontal cortex and hippocampus, but not the cerebellum. Active changes in Tet mRNA levels indicated that TET2 and TET3 predominantly contributed to the changes in 5hmC levels. Our findings provide new insight into the dynamic changes in 5hmC levels in tree shrew brains during postnatal development and aging processes.
基金This work was supported by the National Natural Science Foundation of China(51473024)by University Science Research General Project of Jiangsu Province(16KJD430001)。
文摘Lignin is a natural biopolymer with a complex three-dimensional network, commercially obtained from wasteliquid of paper pulp and bioethanol production, and could be a candidate for preparation of environment-friendlybio-based polyphenol material. In the present work, the demethylated wheat straw alkali lignin (D-Lig), preparedby demethylation of wheat straw alkali lignin (Lig) using an in-situ generated Lewis acid, was used to synthesizebio-based phenol formaldehyde resin adhesive (D-LPF) applied in plywood. Effects of synthetic process’s factors,including lignin substitution for phenol, NaOH concentration and molar ratio of formaldehyde to phenol, on thebonding strength and free formaldehyde content of D-LPF were investigated in detail, and the optimum syntheticprocess of D-LPF was obtained as following: Lignin substitution for phenol 60%, NaOH concentration 5.0% andmolar ratio of formaldehyde to phenol 2.0, and under the optimum reaction condition, the D-LPF presented lower free formaldehyde content (0.18%) and higher bonding strength (2.19 MPa), which was better than those ofcontaining-lignin phenol formaldehyde resin adhesive (LPF). Additionally, the curing behavior of the adhesivewas studied by differential scanning calorimetry (DSC) combined with gel time. It can be obtained that D-LPFresin adhesive had the shortest gel time, and fastest curing rate, compared with those of PF and L-PF resin adhesives. The curing kinetics data was fitted well by Kissinger model using non-isothermal DSC method, and theaverage activation energy value was 85.3 kJ/mol, slightly higher than that of commercial PF resin, while lowerthan that of LPF (90.2 kJ/mol). Finally, based on the analytical results of high temperature fourier transform infrared spectroscopy (FTIR), a possible curing mechanism of D-LPF was proposed.
基金Supported by the National Natural Science Foundation of China A3Foresight Program,No.31261140372Beijing Science and Technology Commission,No.Z151100001615022the Science Foundation of Peking University Cancer Hospital,No.2017-25
文摘BACKGROUND The expression of the membrane receptor protein GFRA1 is frequently upregulated in many cancers,which can promote cancer development by activating the classic RET-RAS-ERK and RET-RAS-PI3K-AKT pathways.Several therapeutic anti-GFRA1 antibody-drug conjugates are under development.Demethylation(or hypomethylation)of GFRA1 CpG islands(dmGFRA1)is associated with increased gene expression and metastasis risk of gastric cancer.However,it is unknown whether dmGFRA1 affects the metastasis of other cancers,including colon cancer(CC).AIM To study whether dmGFRA1 is a driver for CC metastasis and GFRA1 is a potential therapeutic target.METHODS CC and paired surgical margin tissue samples from 144 inpatients and normal colon mucosal biopsies from 21 noncancer patients were included in this study.The methylation status of GFRA1 islands was determined by MethyLight and denaturing high-performance liquid chromatography and bisulfite-sequencing.Kaplan-Meier analysis was used to explore the effect of dmGFRA1 on the survival of CC patients.Impacts of GFRA1 on CC cell proliferation and migration were evaluated by a battery of biological assays in vitro and in vivo.The phosphorylation of AKT and ERK proteins was examined by Western blot analysis.RESULTS The proportion of dmGFRA1 in CC,surgical margin,and normal colon tissues by MethyLight was 68.4%,73.4%,and 35.9%(median;nonparametric test,P=0.001 and<0.001),respectively.Using the median value of dmGFRA1 peak area proportion as the cutoff,the proportion of dmGFRA1-high samples was much higher in poorly differentiated CC samples than in moderately or welldifferentiated samples(92.3%%vs 55.8%,Chi-square test,P=0.002)and significantly higher in CC samples with distant metastasis than in samples without(77.8%vs 46.0%,P=0.021).The overall survival of patients with dmGFRA1-low CC was significantly longer than that of patients with dmGFRA1-high CC(adjusted hazard ratio=0.49,95%confidence interval:0.24-0.98),especially for 89 CC patients with metastatic CC(adjusted hazard ratio=0.41,95%confidence interval:0.18-0.91).These data were confirmed by the mining results from TCGA datasets.Furthermore,GFRA1 overexpression significantly promoted the proliferation/invasion of RKO and HCT116 cells and the growth of RKO cells in nude mice but did not affect their migration.GFRA1 overexpression markedly increased the phosphorylation levels of AKT and ERK proteins,two key molecules in two classic GFRA1 downstream pathways.CONCLUSION GFRA1 expression is frequently reactivated by DNA demethylation in CC tissues and is significantly associated with a poor prognosis in patients with CC,especially those with metastatic CC.GFRA1 can promote the proliferation/growth of CC cells,probably by the activation of AKT and ERK pathways.GFRA1 might be a therapeutic target for CC patients,especially those with metastatic potential.
基金Supported by Beijing Natural Science Foundation,No.7182182the Young Elite Scientist Sponsorship Program by Cast,No.YESS20170089+1 种基金the National Natural Science Foundation of China,No.81600865 and No.81970940the National Science and Technology Major Project of the Ministry of Science and Technology of China,No.2018ZX10302207。
文摘Mesenchymal stem cells(MSCs)are a heterogeneous population that can be isolated from various tissues,including bone marrow,adipose tissue,umbilical cord blood,and craniofacial tissue.MSCs have attracted increasingly more attention over the years due to their regenerative capacity and function in immunomodulation.The foundation of tissue regeneration is the potential of cells to differentiate into multiple cell lineages and give rise to multiple tissue types.In addition,the immunoregulatory function of MSCs has provided insights into therapeutic treatments for immune-mediated diseases.DNA methylation and demethylation are important epigenetic mechanisms that have been shown to modulate embryonic stem cell maintenance,proliferation,differentiation and apoptosis by activating or suppressing a number of genes.In most studies,DNA hypermethylation is associated with gene suppression,while hypomethylation or demethylation is associated with gene activation.The dynamic balance of DNA methylation and demethylation is required for normal mammalian development and inhibits the onset of abnormal phenotypes.However,the exact role of DNA methylation and demethylation in MSC-based tissue regeneration and immunomodulation requires further investigation.In this review,we discuss how DNA methylation and demethylation function in multi-lineage cell differentiation and immunomodulation of MSCs based on previously published work.Furthermore,we discuss the implications of the role of DNA methylation and demethylation in MSCs for the treatment of metabolic or immune-related diseases.
基金the National Key Technology R&D Program of China(2010BAD01B02)the foundation of Postgraduate Research Program of Zhengzhou University,China(12L00403)
文摘Cytosine methylation/demethylation plays pivotal roles in regulating gene expression at a genome-wide level. However, limited reports are available to reveal correlating changes of cytosine methylation and proteomic expression in Brassica napus so far. Therefore, in the present study, global cytosine methylation and proteome were analysed in B. napus after cold treatment by methylation-sensitive amplified polymorphism （MSAP） and two-dimensional protein electrophoresis technology （2-DE）. The results showed that the lowered genome-wide DNA methylation status was revealed after cold treatment, and about 0.88% of discrepancy in DNA methylation was detected between the non-flowering and flowering plants after cold treatment. Moreover, the 52 significantly up-regulated proteins emerged in comparison with the 36 down-regulated proteins, as well as the 14 proteins exclusively detected in the flowering plants. Intriguingly the 8 specifically expressed proteins in the non-flowering plants disappeared in the flowering plants with cold treatment. Therefore, these present data proved that the correlating changes of cytosine methylation and proteomic expression were evidenced under cold treatment in B. napus.
基金supported by the National Natural Science Foundation of China,No.82171270 (to ZL)Public Service Platform for Artificial In telligence Screening and Auxiliary Diagnosis for the Medical and Health Industry,Ministry of Industry and Information Technology of the People's Republic of China,No.2020-0103-3-1 (to ZL)+3 种基金the Natural Science Foundation of Beijing,No.Z200016 (to ZL)Beijing Talents Project,No.2018000021223ZK03 (to ZL)Beijing Municipal Committee of Science and Technology,No.Z201 100005620010 (to ZL)CAMS Innovation Fund for Medical Sciences,No.2019-I2M-5-029 (to YongW)。
文摘Inflammation is closely related to stroke prognosis, and high inflammation status leads to poor functional outcome in stroke. DNA methylation is involved in the pathogenesis and prognosis of stroke. However, the effect of DNA methylation on stroke at high levels of inflammation is unclear. In this study, we constructed a hyperinflammatory cerebral ischemia mouse model and investigated the effect of hypomethylation and hypermethylation on the functional outcome. We constructed a mouse model of transient middle cerebral artery occlusion and treated the mice with lipopolysaccharide to induce a hyperinflammatory state. To investigate the effect of DNA methylation on stroke, we used small molecule inhibitors to restrain the function of key DNA methylation and demethylation enzymes. 2,3,5-Triphenyltetrazolium chloride staining, neurological function scores, neurobehavioral tests, enzyme-linked immunosorbent assay, quantitative reverse transcription PCR and western blot assay were used to evaluate the effects after stroke in mice. We assessed changes in the global methylation status by measuring DNA 5-mc and DNA 5-hmc levels in peripheral blood after the use of the inhibitor. In the group treated with the DNA methylation inhibitor, brain tissue 2,3,5-triphenyltetrazolium chloride staining showed an increase in infarct volume, which was accompanied by a decrease in neurological scores and worsening of neurobehavioral performance. The levels of inflammatory factors interleukin 6 and interleukin-1 beta in ischemic brain tissue and plasma were elevated, indicating increased inflammation. Related inflammatory pathway exploration showed significant overactivation of nuclear factor kappa B. These results suggested that inhibiting DNA methylation led to poor functional outcome in mice with high inflammation following stroke. Further, the effects were reversed by inhibition of DNA demethylation. Our findings suggest that DNA methylation regulates the inflammatory response in stroke and has an important role in the functional outcome of hyperinflammatory stroke.
文摘BACKGROUND Inflammatory bowel disease(IBD)constitutes a substantial risk factor for colorectal cancer.Connexin 43(Cx43)is a protein that forms gap junction(GJ)complexes involved in intercellular communication,and its expression is altered under pathological conditions,such as IBD and cancer.Recent studies have implicated epigenetic processes modulating DNA methylation in the pathogenesis of diverse inflammatory and malignant diseases.The ten-eleven translocation-2(TET-2)enzyme catalyzes the demethylation,hence,regulating the activity of various cancer-promoting and tumor-suppressor genes.AIM To investigate Cx43 and TET-2 expression levels and presence of 5-hydroxymethylcytosine(5-hmC)marks under inflammatory conditions both in vitro and in vivo.METHODS TET-2 expression was evaluated in parental HT-29 cells and in HT-29 cells expressing low or high levels of Cx43,a putative tumor-suppressor gene whose expression varies in IBD and colorectal cancer,and which has been implicated in the inflammatory process and in tumor onset.The dextran sulfate sodium-induced colitis model was reproduced in BALB/c mice to evaluate the expression of TET-2 and Cx43 under inflammatory conditions in vivo.In addition,archived colon tissue sections from normal,IBD(ulcerative colitis),and sporadic colon adenocarcinoma patients were obtained and evaluated for the expression of TET-2 and Cx43.Expression levels were reported at the transcriptional level by quantitative real-time polymerase chain reaction,and at the translational level by Western blotting and immunofluorescence.RESULTS Under inflammatory conditions,Cx43 and TET-2 expression levels increased compared to noninflammatory conditions.TET-2 upregulation was more pronounced in Cx43-deficient cells.Moreover,colon tissue sections from normal,ulcerative colitis,and sporadic colon adenocarcinoma patients corroborated that Cx43 expression increased in IBD and decreased in adenocarcinoma,compared to tissues from non-IBD subjects.However,TET-2 expression and 5-hmC mark levels decreased in samples from patients with ulcerative colitis or cancer.Cx43 and TET-2 expression levels were also investigated in an experimental colitis mouse model.Interestingly,mice exposed to carbenoxolone(CBX),a GJ inhibitor,had upregulated TET-2 levels.Collectively,these results show that TET-2 levels and activity increased under inflammatory conditions,in cells downregulating gap junctional protein Cx43,and in colon tissues from mice exposed to CBX.CONCLUSION These results suggest that TET-2 expression levels,as well as Cx43 expression levels,are modulated in models of intestinal inflammation.We hypothesize that TET-2 may demethylate genes involved in inflammation and tumorigenesis,such as Cx43,potentially contributing to intestinal inflammation and associated carcinogenesis.
文摘Synthesis of 11-demethyl and 6, 6, 11-demethyl calanolides A (6-9) have been carried out by a four-step reaction sequence using a simple approach in order to investigate the structural requirements necessary for antiviral activity.
基金supported by the National University of Singapore Graduate School for Integrative Sciences and Engineering(to BLT)
文摘Environmental enrichment is known to be beneficial for cognitive improvement.In many animal models of neurological disorders and brain injury,EE has also demonstrated neuroprotective benefits in neurodegenerative diseases and in improving recovery after stroke or traumatic brain injury.The exact underlying mechanism for these phenomena has been unclear.Recent findings have now indicated that neuronal activity elicited by environmental enrichment induces Ca2+influx in dorsal root ganglion neurons results in lasting enhancement of CREB-binding protein-mediated histone acetylation.This,in turn,increases the expression of pro-regeneration genes and promotes axonal regeneration.This mechanism associated with neuronal activity elicited by environmental enrichment-mediated pathway is one of several epigenetic mechanisms which modulate axon regeneration upon injury that has recently come to light.The other prominent mechanisms,albeit not yet directly associated with environmental enrichment,include DNA methylation/demethylation and N6-methyladenosine modification of transcripts.In this brief review,I highlight recent work that has shed light on the epigenetic basis of environmental enrichment-based axon regeneration,and discuss the mechanism and pathways involved.I further speculate on the implications of the findings,in conjunction with the other epigenetic mechanisms,that could be harness to promote axon regeneration upon injury.
