Dysregulation of G9a,a histone-lysine N-methyltransferase,has been observed in Alzheimer’s disease and has been correlated with increased levels of chronic inflammation and oxidative stress.Likewise,microRNAs are inv...Dysregulation of G9a,a histone-lysine N-methyltransferase,has been observed in Alzheimer’s disease and has been correlated with increased levels of chronic inflammation and oxidative stress.Likewise,microRNAs are involved in many biological processes and diseases playing a key role in pathogenesis,especially in multifactorial diseases such as Alzheimer’s disease.Therefore,our aim has been to provide partial insights into the interconnection between G9a,microRNAs,oxidative stress,and neuroinflammation.To better understand the biology of G9a,we compared the global microRNA expression between senescence-accelerated mouse-prone 8(SAMP8)control mice and SAMP8 treated with G9a inhibitor UNC0642.We found a downregulation of miR-128 after a G9a inhibition treatment,which interestingly binds to the 3′untranslated region(3′-UTR)of peroxisome-proliferator activator receptor γ(PPARG)mRNA.Accordingly,Pparg gene expression levels were higher in the SAMP8 group treated with G9a inhibitor than in the SAMP8 control group.We also observed modulation of oxidative stress responses might be mainly driven Pparg after G9a inhibitor.To confirm these antioxidant effects,we treated primary neuron cell cultures with hydrogen peroxide as an oxidative insult.In this setting,treatment with G9a inhibitor increases both cell survival and antioxidant enzymes.Moreover,up-regulation of PPARγby G9a inhibitor could also increase the expression of genes involved in DNA damage responses and apoptosis.In addition,we also described that the PPARγ/AMPK axis partially explains the regulation of autophagy markers expression.Finally,PPARγ/GADD45αpotentially contributes to enhancing synaptic plasticity and neurogenesis after G9a inhibition.Altogether,we propose that pharmacological inhibition of G9a leads to a neuroprotective effect that could be due,at least in part,by the modulation of PPARγ-dependent pathways by miR-128.展开更多
Objective:To evaluate the effect of chaetocin on pyroptosis of gastric cancer cells and its underlying mechanisms.Methods:The proliferation of gastric cancer cells was detected by trypan blue staining.Flow cytometry a...Objective:To evaluate the effect of chaetocin on pyroptosis of gastric cancer cells and its underlying mechanisms.Methods:The proliferation of gastric cancer cells was detected by trypan blue staining.Flow cytometry and Hoechst/propidium iodide double staining were used to detect apoptosis and pyroptosis.Cellular ultrastructure was observed by transmission electron microscopy.The levels of p-mixed lineage kinase domain-like(MLKL),gasdermin-D(GSDMD),gasdermin E(GSDME),N-GSDMD,and N-GSDME proteins were detected by Western blotting.In addition,lactate dehydrogenase(LDH)release assay was used to verify pyroptosis induced by chaetocin,and caspase 3 inhibition test and siRNA interference test were conducted to investigate pyroptosis mechanisms.Results:Chaetocin at concentrations of 200 nmol/L to 600 nmol/L inhibited the proliferation of AGS,HGC27,MKN28,and SGC7901gastric cancer cells in a dose-dependent and time-dependent manner by inducing apoptosis and pyroptosis.Significant ultrastructure changes,such as chromatin condensation,vacuolization,disrupted mitochondrial cristae,and increased nuclear occupancy,were observed after treatment with chaetocin in SGC7901 cells.Chaetocin at a concentration of 400 nmol/L significantly increased the number of pyroptotic cells,LDH release,and the ratio of N-GSDME/GSDME(P<0.01),which were reversed by Z-DEVD-FMK.In addition,chaetocin did not affect the expression of GSDMD.G9a silencing abolished the effect of chaetocin on the expression levels of GSDME and N-GSDME and LDH release(P>0.05).Conclusions:In addition to inducing apoptosis,chaetocin inhibits gastric cancer cells by inducing pyroptosis via the caspase 3/GSDME pathway.G9a was the target of chaetocin to induce pyroptosis of gastric cancer cells.展开更多
目的利用药效团模型和分子对接方法对商业化合物库ChemDiv中的G9afocused-libraries进行筛选,希望发现新骨架结构的G9a抑制剂。方法首先,使用Discovery studio 3.1软件分别构建基于配体的药效团模型和基于配体-受体复合物的药效团模型,...目的利用药效团模型和分子对接方法对商业化合物库ChemDiv中的G9afocused-libraries进行筛选,希望发现新骨架结构的G9a抑制剂。方法首先,使用Discovery studio 3.1软件分别构建基于配体的药效团模型和基于配体-受体复合物的药效团模型,并根据构建的2个模型再重新定义2个新的药效团模型。然后,构建测试集并测试药效团模型的预测能力。最后,选取最优药效团模型对G9afocused-libraries进行筛选,对筛选出的化合物使用CDOCKER分子对接进行分析与评价。结果测试结果显示,所构建的药效团模型具有一定的预测能力,通过该药效团筛选得到了2个结构新颖的潜在的G9a抑制剂。结论所构建的药效团模型具有一定的可靠性,虚拟筛选发现的G9a抑制剂还需进一步的实验证明。展开更多
目的:比较弥漫性大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)及淋巴结反应增生组织中组蛋白甲基化酶G9a的表达情况,探讨G9a的表达水平与DLBCL患者的临床特征、病理类型、疗效及预后的关系。方法:分析郑州大学附属肿瘤医院2014...目的:比较弥漫性大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)及淋巴结反应增生组织中组蛋白甲基化酶G9a的表达情况,探讨G9a的表达水平与DLBCL患者的临床特征、病理类型、疗效及预后的关系。方法:分析郑州大学附属肿瘤医院2014年6月至2019年6月经淋巴结活检确诊的75例初治DLBCL患者病理标本及临床资料,同时选取25例淋巴结反应性增生组织标本作为对照组。采用免疫组织化学法检测DLBCL和对照组中G9a蛋白的表达,分析G9a蛋白表达与DLBCL患者临床病理特征、疗效及预后的关系。采用完全缓解(complete response,CR)率、总生存(overall survival,OS)率、无进展期生存(progression-free survival,PFS)率探讨其对患者生存及预后的影响。结果:DLBCL组织G9a蛋白阳性表达率为65.3%,明显高于淋巴结反应性增生组织20.0%,且差异具有统计学意义(P<0.001)。G9a蛋白阳性与阴性患者的性别、年龄、B症状、LDH水平、初治缓解率的差异均无统计学意义(均P>0.05)。G9a蛋白阳性患者组的β2-MG的值,临床分期,Ki-67均较G9a蛋白阴性组更高,且差异均具有统计学意义(P值分别为0.041、0.019和0.044),Non-GCB的G9a表达率高于GCB组,差异具有统计学意义(P=0.023)。虽然Cox多因素分析显示,G9a蛋白表达阳性并非是是影响DLBCL患者3年OS和PFS的独立危险因素,但单因素研究显示G9a蛋白阴性和阳性组的3年OS分别为89.5%和74.4%,且两组差异具有统计学意义(P=0.043),3年PFS分别为79.3%和59.4%,两组差异具有统计学意义(P=0.038)。结论:与淋巴结反应性增生组织相比,组蛋白甲基化酶G9a在DLBCL中表达明显增加,且G9a蛋白阳性DLBCL患者的β2-MG、临床分期、Ki-67指数均较G9a蛋白表达阴性患者更高,提示G9a阳性表达可能与DLBCL的发展增殖有关;G9a蛋白表达阳性是影响初治DLBCL患者3年OS和PFS的不良预后因素之一,但并非其独立预后因素。展开更多
Objective： To investigate the mRNA and protein expression of histone methyltransferase G9a and its clinical significance in extrahepatic cholangiocarcinoma. Methods： Using RT-PCR and Western Blotting to detect the e...Objective： To investigate the mRNA and protein expression of histone methyltransferase G9a and its clinical significance in extrahepatic cholangiocarcinoma. Methods： Using RT-PCR and Western Blotting to detect the expression of G9a at the level of mRNA and protein in 48 tumor samples and 39 control tissues. Results： The mRNA and protein expression of Gga in extrahepatic cholangiocarcinoma was higher than control statistically （P 〈 0.05） and positively correlated with lymph metastasis （P 〈 0.05） and TNM stage （P 〈 0.01）. Conclusion： The significant difference of Gga expression between tumors and control implicated that the important role of histone methylation disruption resulted from increased G9a expression in extrahepatic cholangiocarcinoma.展开更多
基金supported by the Ministerio de Economía,Industria y Competitividad(Agencia Estatal de Investigación,AEI,to CGF and MP)Fondo Europeo de Desarrollo Regional(MINECO-FEDER)(PID2022-139016OA-I00,PDC2022-133441-I00,to CGF and MP),Generalitat de Catalunya(2021 SGR 00357+3 种基金to CGF and MP)co-financed by Secretaria d’Universitats i Recerca del Departament d’Empresai Coneixement de la Generalitat de Catalunya 2021(Llavor 00086,to CGF)the recipient of an Alzheimer’s Association Research Fellowship(AARF-21-848511)the Agència de Gestiód’Ajuts Universitaris i de Recerca(AGAUR)for her FI-SDUR fellowship(2021FISDU 00182).
文摘Dysregulation of G9a,a histone-lysine N-methyltransferase,has been observed in Alzheimer’s disease and has been correlated with increased levels of chronic inflammation and oxidative stress.Likewise,microRNAs are involved in many biological processes and diseases playing a key role in pathogenesis,especially in multifactorial diseases such as Alzheimer’s disease.Therefore,our aim has been to provide partial insights into the interconnection between G9a,microRNAs,oxidative stress,and neuroinflammation.To better understand the biology of G9a,we compared the global microRNA expression between senescence-accelerated mouse-prone 8(SAMP8)control mice and SAMP8 treated with G9a inhibitor UNC0642.We found a downregulation of miR-128 after a G9a inhibition treatment,which interestingly binds to the 3′untranslated region(3′-UTR)of peroxisome-proliferator activator receptor γ(PPARG)mRNA.Accordingly,Pparg gene expression levels were higher in the SAMP8 group treated with G9a inhibitor than in the SAMP8 control group.We also observed modulation of oxidative stress responses might be mainly driven Pparg after G9a inhibitor.To confirm these antioxidant effects,we treated primary neuron cell cultures with hydrogen peroxide as an oxidative insult.In this setting,treatment with G9a inhibitor increases both cell survival and antioxidant enzymes.Moreover,up-regulation of PPARγby G9a inhibitor could also increase the expression of genes involved in DNA damage responses and apoptosis.In addition,we also described that the PPARγ/AMPK axis partially explains the regulation of autophagy markers expression.Finally,PPARγ/GADD45αpotentially contributes to enhancing synaptic plasticity and neurogenesis after G9a inhibition.Altogether,we propose that pharmacological inhibition of G9a leads to a neuroprotective effect that could be due,at least in part,by the modulation of PPARγ-dependent pathways by miR-128.
基金supported by Natural Science Foundation of Hainan Province,China(No.820MS048)。
文摘Objective:To evaluate the effect of chaetocin on pyroptosis of gastric cancer cells and its underlying mechanisms.Methods:The proliferation of gastric cancer cells was detected by trypan blue staining.Flow cytometry and Hoechst/propidium iodide double staining were used to detect apoptosis and pyroptosis.Cellular ultrastructure was observed by transmission electron microscopy.The levels of p-mixed lineage kinase domain-like(MLKL),gasdermin-D(GSDMD),gasdermin E(GSDME),N-GSDMD,and N-GSDME proteins were detected by Western blotting.In addition,lactate dehydrogenase(LDH)release assay was used to verify pyroptosis induced by chaetocin,and caspase 3 inhibition test and siRNA interference test were conducted to investigate pyroptosis mechanisms.Results:Chaetocin at concentrations of 200 nmol/L to 600 nmol/L inhibited the proliferation of AGS,HGC27,MKN28,and SGC7901gastric cancer cells in a dose-dependent and time-dependent manner by inducing apoptosis and pyroptosis.Significant ultrastructure changes,such as chromatin condensation,vacuolization,disrupted mitochondrial cristae,and increased nuclear occupancy,were observed after treatment with chaetocin in SGC7901 cells.Chaetocin at a concentration of 400 nmol/L significantly increased the number of pyroptotic cells,LDH release,and the ratio of N-GSDME/GSDME(P<0.01),which were reversed by Z-DEVD-FMK.In addition,chaetocin did not affect the expression of GSDMD.G9a silencing abolished the effect of chaetocin on the expression levels of GSDME and N-GSDME and LDH release(P>0.05).Conclusions:In addition to inducing apoptosis,chaetocin inhibits gastric cancer cells by inducing pyroptosis via the caspase 3/GSDME pathway.G9a was the target of chaetocin to induce pyroptosis of gastric cancer cells.
文摘目的利用药效团模型和分子对接方法对商业化合物库ChemDiv中的G9afocused-libraries进行筛选,希望发现新骨架结构的G9a抑制剂。方法首先,使用Discovery studio 3.1软件分别构建基于配体的药效团模型和基于配体-受体复合物的药效团模型,并根据构建的2个模型再重新定义2个新的药效团模型。然后,构建测试集并测试药效团模型的预测能力。最后,选取最优药效团模型对G9afocused-libraries进行筛选,对筛选出的化合物使用CDOCKER分子对接进行分析与评价。结果测试结果显示,所构建的药效团模型具有一定的预测能力,通过该药效团筛选得到了2个结构新颖的潜在的G9a抑制剂。结论所构建的药效团模型具有一定的可靠性,虚拟筛选发现的G9a抑制剂还需进一步的实验证明。
基金Supported by a grant from the National High Technology ResearchDevelopment Program of China (863 Program) (No. 2002AA214061)
文摘Objective： To investigate the mRNA and protein expression of histone methyltransferase G9a and its clinical significance in extrahepatic cholangiocarcinoma. Methods： Using RT-PCR and Western Blotting to detect the expression of G9a at the level of mRNA and protein in 48 tumor samples and 39 control tissues. Results： The mRNA and protein expression of Gga in extrahepatic cholangiocarcinoma was higher than control statistically （P 〈 0.05） and positively correlated with lymph metastasis （P 〈 0.05） and TNM stage （P 〈 0.01）. Conclusion： The significant difference of Gga expression between tumors and control implicated that the important role of histone methylation disruption resulted from increased G9a expression in extrahepatic cholangiocarcinoma.
