AIM:To explore the effect of silent information regulator factor 2-related enzyme 1(SIRT1)on modulating apoptosis of human lens epithelial cells(HLECs)and alleviating lens opacification of rats through suppressing end...AIM:To explore the effect of silent information regulator factor 2-related enzyme 1(SIRT1)on modulating apoptosis of human lens epithelial cells(HLECs)and alleviating lens opacification of rats through suppressing endoplasmic reticulum(ER)stress.METHODS:HLECs(SRA01/04)were treated with varying concentrations of tunicamycin(TM)for 24h,and the expression of SIRT1 and C/EBP homologous protein(CHOP)was assessed using real-time quantitative polymerase chain reaction(RT-PCR),Western blotting,and immunofluorescence.Cell morphology and proliferation was evaluated using an inverted microscope and cell counting kit-8(CCK-8)assay,respectively.In the SRA01/04 cell apoptosis model,which underwent siRNA transfection for SIRT1 knockdown and SRT1720 treatment for its activation,the expression levels of SIRT1,CHOP,glucose regulated protein 78(GRP78),and activating transcription factor 4(ATF4)were examined.The potential reversal of SIRT1 knockdown effects by 4-phenyl butyric acid(4-PBA;an ER stress inhibitor)was investigated.In vivo,age-related cataract(ARC)rat models were induced by sodium selenite injection,and the protective role of SIRT1,activated by SRT1720 intraperitoneal injections,was evaluated through morphology observation,hematoxylin and eosin(H&E)staining,Western blotting,and RT-PCR.RESULTS:SIRT1 expression was downregulated in TMinduced SRA01/04 cells.Besides,in SRA01/04 cells,both cell apoptosis and CHOP expression increased with the rising doses of TM.ER stress was stimulated by TM,as evidenced by the increased GRP78 and ATF4 in the SRA01/04 cell apoptosis model.Inhibition of SIRT1 by siRNA knockdown increased ER stress activation,whereas SRT1720 treatment had opposite results.4-PBA partly reverse the adverse effect of SIRT1 knockdown on apoptosis.In vivo,SRT1720 attenuated the lens opacification and weakened the ER stress activation in ARC rat models.CONCLUSION:SIRT1 plays a protective role against TM-induced apoptosis in HLECs and slows the progression of cataract in rats by inhibiting ER stress.These findings suggest a novel strategy for cataract treatment focused on targeting ER stress,highlighting the therapeutic potential of SIRT1 modulation in ARC development.展开更多
Sirtuin家族是酵母沉默信息调节因子(silent information regulator factor)在哺乳动物中的同源物,属于Ⅲ类组蛋白去乙酰化酶。沉默信息调节因子2相关酶1(silent information regulator factor 2-related enzyme 1,SIRT1)是Sirtuin家族...Sirtuin家族是酵母沉默信息调节因子(silent information regulator factor)在哺乳动物中的同源物,属于Ⅲ类组蛋白去乙酰化酶。沉默信息调节因子2相关酶1(silent information regulator factor 2-related enzyme 1,SIRT1)是Sirtuin家族目前研究最为充分的成员之一。主要分布于细胞核及细胞质,通过行使其NAD+依赖的去乙酰化活性,参与调节DNA损伤修复、基因转录、能量代谢、应激及凋亡等细胞生理过程。细胞凋亡是在精确的内在遗传调控下发生的一种程序性死亡,旨在维持机体内环境稳态。异常的细胞凋亡参与多种疾病的发生,例如肿瘤、神经退行性病变、自身免疫病和缺血性疾病等,了解细胞凋亡的机制对于这些疾病的治疗有着极为重要的意义。SIRT1除靶向组蛋白外,还作用于多种非组蛋白质例如转录因子和蛋白激酶等,其中有很多非组蛋白分子都与细胞凋亡息息相关。本文总结了SIRT1通过调控相关下游非组蛋白分子p53、叉头转录因子FOXO3a、AMP依赖的蛋白激酶(AMPK)、核转录因子NF-κB、ku70蛋白、转录因子E2F1和缺氧诱导因子-1α的乙酰化修饰水平,进而影响基因转录、DNA损伤修复、炎症、氧化应激等过程,直接或间接触发细胞凋亡的分子机制。希望通过调控SIRT1表达来影响其下游非组蛋白分子的乙酰化修饰水平,进而对细胞凋亡进行干预,为多种相关疾病的治疗提供新的靶点。展开更多
基金Supported by National Natural Science Foundation for Young Scientists of China(No.82101097)National Natural Science Foundation of China(No.82070937).
文摘AIM:To explore the effect of silent information regulator factor 2-related enzyme 1(SIRT1)on modulating apoptosis of human lens epithelial cells(HLECs)and alleviating lens opacification of rats through suppressing endoplasmic reticulum(ER)stress.METHODS:HLECs(SRA01/04)were treated with varying concentrations of tunicamycin(TM)for 24h,and the expression of SIRT1 and C/EBP homologous protein(CHOP)was assessed using real-time quantitative polymerase chain reaction(RT-PCR),Western blotting,and immunofluorescence.Cell morphology and proliferation was evaluated using an inverted microscope and cell counting kit-8(CCK-8)assay,respectively.In the SRA01/04 cell apoptosis model,which underwent siRNA transfection for SIRT1 knockdown and SRT1720 treatment for its activation,the expression levels of SIRT1,CHOP,glucose regulated protein 78(GRP78),and activating transcription factor 4(ATF4)were examined.The potential reversal of SIRT1 knockdown effects by 4-phenyl butyric acid(4-PBA;an ER stress inhibitor)was investigated.In vivo,age-related cataract(ARC)rat models were induced by sodium selenite injection,and the protective role of SIRT1,activated by SRT1720 intraperitoneal injections,was evaluated through morphology observation,hematoxylin and eosin(H&E)staining,Western blotting,and RT-PCR.RESULTS:SIRT1 expression was downregulated in TMinduced SRA01/04 cells.Besides,in SRA01/04 cells,both cell apoptosis and CHOP expression increased with the rising doses of TM.ER stress was stimulated by TM,as evidenced by the increased GRP78 and ATF4 in the SRA01/04 cell apoptosis model.Inhibition of SIRT1 by siRNA knockdown increased ER stress activation,whereas SRT1720 treatment had opposite results.4-PBA partly reverse the adverse effect of SIRT1 knockdown on apoptosis.In vivo,SRT1720 attenuated the lens opacification and weakened the ER stress activation in ARC rat models.CONCLUSION:SIRT1 plays a protective role against TM-induced apoptosis in HLECs and slows the progression of cataract in rats by inhibiting ER stress.These findings suggest a novel strategy for cataract treatment focused on targeting ER stress,highlighting the therapeutic potential of SIRT1 modulation in ARC development.
文摘Sirtuin家族是酵母沉默信息调节因子(silent information regulator factor)在哺乳动物中的同源物,属于Ⅲ类组蛋白去乙酰化酶。沉默信息调节因子2相关酶1(silent information regulator factor 2-related enzyme 1,SIRT1)是Sirtuin家族目前研究最为充分的成员之一。主要分布于细胞核及细胞质,通过行使其NAD+依赖的去乙酰化活性,参与调节DNA损伤修复、基因转录、能量代谢、应激及凋亡等细胞生理过程。细胞凋亡是在精确的内在遗传调控下发生的一种程序性死亡,旨在维持机体内环境稳态。异常的细胞凋亡参与多种疾病的发生,例如肿瘤、神经退行性病变、自身免疫病和缺血性疾病等,了解细胞凋亡的机制对于这些疾病的治疗有着极为重要的意义。SIRT1除靶向组蛋白外,还作用于多种非组蛋白质例如转录因子和蛋白激酶等,其中有很多非组蛋白分子都与细胞凋亡息息相关。本文总结了SIRT1通过调控相关下游非组蛋白分子p53、叉头转录因子FOXO3a、AMP依赖的蛋白激酶(AMPK)、核转录因子NF-κB、ku70蛋白、转录因子E2F1和缺氧诱导因子-1α的乙酰化修饰水平,进而影响基因转录、DNA损伤修复、炎症、氧化应激等过程,直接或间接触发细胞凋亡的分子机制。希望通过调控SIRT1表达来影响其下游非组蛋白分子的乙酰化修饰水平,进而对细胞凋亡进行干预,为多种相关疾病的治疗提供新的靶点。
