探究鸠坑龙井茶水提物(LJT)对小鼠肝组织脂质代谢SREBPs通路信号影响及肠道菌群的调节作用。通过高脂饮食诱导小鼠构建非酒精性脂肪肝(NAFL)模型,并给予LJT(300 mg·kg^(-1))灌胃干预。定期记录小鼠的体质量,检测小鼠血清生化指标...探究鸠坑龙井茶水提物(LJT)对小鼠肝组织脂质代谢SREBPs通路信号影响及肠道菌群的调节作用。通过高脂饮食诱导小鼠构建非酒精性脂肪肝(NAFL)模型,并给予LJT(300 mg·kg^(-1))灌胃干预。定期记录小鼠的体质量,检测小鼠血清生化指标和葡萄糖耐受水平,观察并分析Hematoxylin-Eosin(HE)染色、油红O染色肝组织切片特征;应用Real-time qPCR技术检测小鼠肝组织SREBPs通路7个基因(SREBP-1c、FAS、SCD-1、ACC-1、SREBP-2、HMGCR、PPARγ)的相对表达量,采用蛋白免疫印记技术(Western Blot)分析肝组织蛋白质表达水平,同时对小鼠肠道菌群进行高通量测序(16 S rDNA)并分析其结构。结果显示,LJT干预后小鼠体质量、血糖AUC、血清TG、TC、LDL-C和肝脏中TG、TC水平有显著下降,龙井组小鼠肝组织SREBP-1c、FAS、ACC-1、SCD-1和PPARγ蛋白表达水平降低,SREBP-1c、SCD-1、FAS、ACC-1、SREBP-2、HMGCR、PPARγ基因的相对表达量显著下调;16 S rDNA分析发现,小鼠肠道菌群门水平主要为Firmicutes、Bacteroidota、Desulfobacterota和Actinobacteriota 4类,LJT有效延缓了高脂饮食引起的Firmicutes相对丰度升高和Bacteroidota相对丰度下降趋势,并增加了肠道菌群的物种丰度。结果表明,LJT能够干预小鼠肝脂肪变性SREBPs通路信号表达,改善小鼠肠道菌群紊乱,具有降脂减肥作用。展开更多
茶叶可调节不同组织的脂质代谢,抑制肠道消化吸收脂质,起到降脂减肥作用。茶叶对脂质代谢途径具有显著影响,主要通过调控固醇调节元件结合蛋白(Sterol Regulatory Element Binding Proteins)及其上下游因子表达,影响脂质合成和分解,从...茶叶可调节不同组织的脂质代谢,抑制肠道消化吸收脂质,起到降脂减肥作用。茶叶对脂质代谢途径具有显著影响,主要通过调控固醇调节元件结合蛋白(Sterol Regulatory Element Binding Proteins)及其上下游因子表达,影响脂质合成和分解,从而降低脂肪积累。展开更多
As a culinary and medicinal herb, rosemary is widely used. The present work aimed to investigate the effects of rosemary extracts on metabolic diseases and the underlying mechanisms of action. Liver cells stably expre...As a culinary and medicinal herb, rosemary is widely used. The present work aimed to investigate the effects of rosemary extracts on metabolic diseases and the underlying mechanisms of action. Liver cells stably expressing SREBP reporter were used to evaluate the inhibitory effects of different fractions of rosemary extracts on SREBP activity. The obese mice induced by Western-type diet were orally administered with rosemary extracts or vehicle for 7 weeks, the plasma and tissue lipids were analyzed. SREBPs and their target genes were measured by quantitative RT-PCR. We demonstrated that the petroleum ether sub-fraction of rosemary extracts(PER) exhibited the best activity in regulating lipid metabolism by inhibiting SREBPs, while water and n-Bu OH sub-fraction showed the SREBPs agonist-effect. After PER treatment, there was a significant reduction of total SREBPs in liver cells. PER not only decreased SREBPs nuclear abundance, but also inhibited their activity, resulting in decreased expression of SREBP-1c and SREBP-2 target genes in vitro and in vivo. Inhibiting SREBPs by PER decreased the total triglycerides and cholesterol contents of the liver cells. In the mice fed with Western-type diet, PER treatment decreased TG, TC, ALT, glucose, and insulin in blood, and improved glucose tolerance and insulin sensitivity. Furthermore, PER treatment also decreased lipid contents in liver, brown adipose tissue, and white adipose tissue. Our results from the present study suggested that petroleum ether fraction of rosemary extracts exhibited the best potential of improving lipid metabolism by inhibiting SREBPs activity.展开更多
Sterol regulator element binding proteins(SREBPs)are a family of transcription factors involved in the biogenesis of cholesterol,fatty acids and triglycerides.They also regulate physiological functions of many organs,...Sterol regulator element binding proteins(SREBPs)are a family of transcription factors involved in the biogenesis of cholesterol,fatty acids and triglycerides.They also regulate physiological functions of many organs,such as thyroid,brain,heart,pancreas and hormone synthesis.Beside the physiological effects,SREBPs participate in some pathological processes,diabetes,endoplasmic reticulum stress,atherosclerosis and chronic kidney disease associated with SREBP expression changes.In the liver,SREBPs are involved in the pathogenesis of nonalcoholic fatty liver disease,nonalcoholic steatohepatitis,hepatitis and hepatic cancer.There are several SREBP inhibitors that have potential for treating obesity,diabetes and cancer.This review assesses the recent findings about the roles of SREBPs in the physiology of organs'function and pathogenesis of liver diseases.展开更多
The mammalian target of rapamycin(mTOR)-sterol regulatory element-binding proteins(SREBPs)signaling promotes lipogenesis.However,mTOR inhibitors also displayed a significant side effect of hyperlipidemia.Thus,it is es...The mammalian target of rapamycin(mTOR)-sterol regulatory element-binding proteins(SREBPs)signaling promotes lipogenesis.However,mTOR inhibitors also displayed a significant side effect of hyperlipidemia.Thus,it is essential to develop mTOR-specific inhibitors to inhibit lipogenesis.Here,we screened the endogenous inhibitors of mTOR,and identified that FKBP38 as a vital regulator of lipid metabolism.FKBP38 decreased the lipid content in vitro and in vivo via suppression of the mTOR/P70 S6 K/SREBPs pathway.3,5,6,7,8,3’,4’-Heptamethoxyflavone(HMF),a citrus flavonoid,was found to target FKBP38 to suppress the mTOR/P70 S6 K/SREBPs pathway,reduce lipid level,and potently ameliorate hyperlipidemia and insulin resistance in high fat diet(HFD)-fed mice.Our findings suggest that pharmacological intervention by targeting FKBP38 to suppress mTOR/P70 S6 K/SREBPs pathway is a potential therapeutic strategy for hyperlipidemia,and HMF could be a leading compound for development of anti-hyperlipidemia drugs.展开更多
Osteoclasts are multinucleated bone-resorbing cells,and their formation is tightly regulated to prevent excessive bone loss.However,the mechanisms by which osteoclast formation is restricted remain incompletely determ...Osteoclasts are multinucleated bone-resorbing cells,and their formation is tightly regulated to prevent excessive bone loss.However,the mechanisms by which osteoclast formation is restricted remain incompletely determined.Here,we found that sterol regulatory element binding protein 2(SREBP2)functions as a negative regulator of osteoclast formation and inflammatory bone loss.Cholesterols and SREBP2,a key transcription factor for cholesterol biosynthesis,increased in the late phase of osteoclastogenesis.展开更多
目的研究固醇调节元件结合蛋白1c(sterol regulatory element binding protein 1c,SREBP1c)对肠道糖异生的调控作用。方法饥饿处理C57BL/6小鼠、SREBP1c纯合敲除型(SREBP1c-KO)和同窝野生型(SREBP1c-WT)小鼠,通过qPCR、Western blot检...目的研究固醇调节元件结合蛋白1c(sterol regulatory element binding protein 1c,SREBP1c)对肠道糖异生的调控作用。方法饥饿处理C57BL/6小鼠、SREBP1c纯合敲除型(SREBP1c-KO)和同窝野生型(SREBP1c-WT)小鼠,通过qPCR、Western blot检测糖异生途径限速酶葡萄糖-6-磷酸酶(glucose-6-phosphatase catalytic,G6PC)和磷酸烯醇式丙酮酸羧激酶(phosphoenolpyruvate carboxykinase 1,PCK1)在肝脏、空肠和回肠组织中的表达水平;在肠上皮细胞CaCo-2中过表达或敲低SREBP1c,检测细胞内G6PC和PCK1表达水平。结果饥饿处理后,C57BL/6小鼠空肠、回肠组织中G6PC、PCK1和SREBP1c表达水平均显著增加(P<0.05)。SREBP1c基因敲除后,小鼠空肠、回肠组织中由饥饿诱导的糖异生限速酶G6PC和PCK1的表达明显下调(P<0.05)。在肠上皮细胞CaCo-2中过表达SREBP1c,可显著上调糖异生途径关键酶G6PC和PCK1的表达,促进细胞内葡萄糖的产生(P<0.05);反之,敲低SREBP1c的表达,可明显下调G6PC和PCK1,抑制细胞内葡萄糖的产生(P<0.05)。结论饥饿状态下,SREBP1c可调控肠上皮细胞中糖异生限速酶G6PC和PCK1的表达,进而影响葡萄糖的生成,表明SREBP1c可能参与肠道糖异生的调控,机制有待进一步探索。展开更多
目的筛选影响胆固醇调节元件结合蛋白1a(cholesterol regulatory element binding protein,SREBP1a)蛋白稳定性的去泛素化酶,并探索其调控机制。方法通过去泛素化酶库筛选显著影响SREBP1a表达的去泛素化酶,免疫蛋白印记实验和实时荧光定...目的筛选影响胆固醇调节元件结合蛋白1a(cholesterol regulatory element binding protein,SREBP1a)蛋白稳定性的去泛素化酶,并探索其调控机制。方法通过去泛素化酶库筛选显著影响SREBP1a表达的去泛素化酶,免疫蛋白印记实验和实时荧光定量PCR(qRT-PCR)评估去泛素化酶对SREBP1a以及升脂基因表达的影响;通过红色荧光蛋白标记人源低密度脂蛋白(human Dil-low density lipoprotein,Human Dil-LDL)摄取和油红O染色等实验技术检测细胞摄取低密度脂蛋白(LDL)和脂质沉积情况。结果去泛素化酶库筛选发现泛素特异肽酶37(ubiquitin specific peptidase 37,USP37)可显著增加肝细胞SREBP1a蛋白表达水平,促进胆固醇摄取及脂质沉积。USP37基因敲除可显著降低SREBP1a蛋白表达水平,抑制升脂基因表达及脂质沉积。结论去泛素化酶USP37通过稳定SREBP1a蛋白表达,促进胆固醇摄取及脂质沉积,揭示了SREBP1a翻译后调控的新模式。展开更多
文摘探究鸠坑龙井茶水提物(LJT)对小鼠肝组织脂质代谢SREBPs通路信号影响及肠道菌群的调节作用。通过高脂饮食诱导小鼠构建非酒精性脂肪肝(NAFL)模型,并给予LJT(300 mg·kg^(-1))灌胃干预。定期记录小鼠的体质量,检测小鼠血清生化指标和葡萄糖耐受水平,观察并分析Hematoxylin-Eosin(HE)染色、油红O染色肝组织切片特征;应用Real-time qPCR技术检测小鼠肝组织SREBPs通路7个基因(SREBP-1c、FAS、SCD-1、ACC-1、SREBP-2、HMGCR、PPARγ)的相对表达量,采用蛋白免疫印记技术(Western Blot)分析肝组织蛋白质表达水平,同时对小鼠肠道菌群进行高通量测序(16 S rDNA)并分析其结构。结果显示,LJT干预后小鼠体质量、血糖AUC、血清TG、TC、LDL-C和肝脏中TG、TC水平有显著下降,龙井组小鼠肝组织SREBP-1c、FAS、ACC-1、SCD-1和PPARγ蛋白表达水平降低,SREBP-1c、SCD-1、FAS、ACC-1、SREBP-2、HMGCR、PPARγ基因的相对表达量显著下调;16 S rDNA分析发现,小鼠肠道菌群门水平主要为Firmicutes、Bacteroidota、Desulfobacterota和Actinobacteriota 4类,LJT有效延缓了高脂饮食引起的Firmicutes相对丰度升高和Bacteroidota相对丰度下降趋势,并增加了肠道菌群的物种丰度。结果表明,LJT能够干预小鼠肝脂肪变性SREBPs通路信号表达,改善小鼠肠道菌群紊乱,具有降脂减肥作用。
基金supported by the Funds for Creative Research Groups of ChinaNational Natural Science Foundation of China(No.81421005)National Natural Science Foundation of China(No.81274159)
文摘As a culinary and medicinal herb, rosemary is widely used. The present work aimed to investigate the effects of rosemary extracts on metabolic diseases and the underlying mechanisms of action. Liver cells stably expressing SREBP reporter were used to evaluate the inhibitory effects of different fractions of rosemary extracts on SREBP activity. The obese mice induced by Western-type diet were orally administered with rosemary extracts or vehicle for 7 weeks, the plasma and tissue lipids were analyzed. SREBPs and their target genes were measured by quantitative RT-PCR. We demonstrated that the petroleum ether sub-fraction of rosemary extracts(PER) exhibited the best activity in regulating lipid metabolism by inhibiting SREBPs, while water and n-Bu OH sub-fraction showed the SREBPs agonist-effect. After PER treatment, there was a significant reduction of total SREBPs in liver cells. PER not only decreased SREBPs nuclear abundance, but also inhibited their activity, resulting in decreased expression of SREBP-1c and SREBP-2 target genes in vitro and in vivo. Inhibiting SREBPs by PER decreased the total triglycerides and cholesterol contents of the liver cells. In the mice fed with Western-type diet, PER treatment decreased TG, TC, ALT, glucose, and insulin in blood, and improved glucose tolerance and insulin sensitivity. Furthermore, PER treatment also decreased lipid contents in liver, brown adipose tissue, and white adipose tissue. Our results from the present study suggested that petroleum ether fraction of rosemary extracts exhibited the best potential of improving lipid metabolism by inhibiting SREBPs activity.
文摘Sterol regulator element binding proteins(SREBPs)are a family of transcription factors involved in the biogenesis of cholesterol,fatty acids and triglycerides.They also regulate physiological functions of many organs,such as thyroid,brain,heart,pancreas and hormone synthesis.Beside the physiological effects,SREBPs participate in some pathological processes,diabetes,endoplasmic reticulum stress,atherosclerosis and chronic kidney disease associated with SREBP expression changes.In the liver,SREBPs are involved in the pathogenesis of nonalcoholic fatty liver disease,nonalcoholic steatohepatitis,hepatitis and hepatic cancer.There are several SREBP inhibitors that have potential for treating obesity,diabetes and cancer.This review assesses the recent findings about the roles of SREBPs in the physiology of organs'function and pathogenesis of liver diseases.
基金financial support from the National Natural Science Foundation of China(81922072 and 81973443)“Double First-Class”University project(CPU2018PZQ16 and CPU2018GF04,China)+2 种基金the Project of State Key Laboratory of Natural Medicines(SKLNMZZ202006,China)the Open Project of State Key Laboratory of Natural Medicines(SKLNMKF202010,China)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(China)。
文摘The mammalian target of rapamycin(mTOR)-sterol regulatory element-binding proteins(SREBPs)signaling promotes lipogenesis.However,mTOR inhibitors also displayed a significant side effect of hyperlipidemia.Thus,it is essential to develop mTOR-specific inhibitors to inhibit lipogenesis.Here,we screened the endogenous inhibitors of mTOR,and identified that FKBP38 as a vital regulator of lipid metabolism.FKBP38 decreased the lipid content in vitro and in vivo via suppression of the mTOR/P70 S6 K/SREBPs pathway.3,5,6,7,8,3’,4’-Heptamethoxyflavone(HMF),a citrus flavonoid,was found to target FKBP38 to suppress the mTOR/P70 S6 K/SREBPs pathway,reduce lipid level,and potently ameliorate hyperlipidemia and insulin resistance in high fat diet(HFD)-fed mice.Our findings suggest that pharmacological intervention by targeting FKBP38 to suppress mTOR/P70 S6 K/SREBPs pathway is a potential therapeutic strategy for hyperlipidemia,and HMF could be a leading compound for development of anti-hyperlipidemia drugs.
文摘目的:探讨固醇调节元件结合蛋白(sterol regulatory elementbinding proteins,SREBPs)与冠心病的相关性。方法:选择冠心病患者65例及正常对照55例,利用RT-qPCR方法检测外周血白细胞SREBP1及SREBP2相对表达量;利用全自动生化分析仪检测血糖血脂等生化项目;使用受试者工作特征(receiver operating characteristic,ROC)曲线和曲线下面积(area under the curve,AUC)分析SREBPs对冠心病诊断的敏感度和特异度。结果:与对照组相比,冠心病组SREBP1及SREBP2相对表达量均显著下降,差异有统计学意义(P<0.001);SREBPs的ROC结果显示,SREBP1的AUC值为0.710,SREBP2的AUC值为0.697。结论:静脉血白细胞中SREBPs下调可能预示冠心病的发生。推测SREBPs可能成为冠心病早期诊断的一个潜在的生物标志物。
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin diseases (NIAMS)of NIH under Award Number R01 AR069562 and AR073156 (to K.H.P.-M.)by the National Research Foundation of Korea NRF2020R1A6A3A03037133 (to H.K.)+1 种基金by the support for the Rosensweig Genomics Center from The Tow Foundation,and by R03 AR068118 (to L.D.)NIH/NCI Cancer Center Support Grant P30 CA008748 (to L.D.)。
文摘Osteoclasts are multinucleated bone-resorbing cells,and their formation is tightly regulated to prevent excessive bone loss.However,the mechanisms by which osteoclast formation is restricted remain incompletely determined.Here,we found that sterol regulatory element binding protein 2(SREBP2)functions as a negative regulator of osteoclast formation and inflammatory bone loss.Cholesterols and SREBP2,a key transcription factor for cholesterol biosynthesis,increased in the late phase of osteoclastogenesis.
文摘目的研究固醇调节元件结合蛋白1c(sterol regulatory element binding protein 1c,SREBP1c)对肠道糖异生的调控作用。方法饥饿处理C57BL/6小鼠、SREBP1c纯合敲除型(SREBP1c-KO)和同窝野生型(SREBP1c-WT)小鼠,通过qPCR、Western blot检测糖异生途径限速酶葡萄糖-6-磷酸酶(glucose-6-phosphatase catalytic,G6PC)和磷酸烯醇式丙酮酸羧激酶(phosphoenolpyruvate carboxykinase 1,PCK1)在肝脏、空肠和回肠组织中的表达水平;在肠上皮细胞CaCo-2中过表达或敲低SREBP1c,检测细胞内G6PC和PCK1表达水平。结果饥饿处理后,C57BL/6小鼠空肠、回肠组织中G6PC、PCK1和SREBP1c表达水平均显著增加(P<0.05)。SREBP1c基因敲除后,小鼠空肠、回肠组织中由饥饿诱导的糖异生限速酶G6PC和PCK1的表达明显下调(P<0.05)。在肠上皮细胞CaCo-2中过表达SREBP1c,可显著上调糖异生途径关键酶G6PC和PCK1的表达,促进细胞内葡萄糖的产生(P<0.05);反之,敲低SREBP1c的表达,可明显下调G6PC和PCK1,抑制细胞内葡萄糖的产生(P<0.05)。结论饥饿状态下,SREBP1c可调控肠上皮细胞中糖异生限速酶G6PC和PCK1的表达,进而影响葡萄糖的生成,表明SREBP1c可能参与肠道糖异生的调控,机制有待进一步探索。
文摘目的筛选影响胆固醇调节元件结合蛋白1a(cholesterol regulatory element binding protein,SREBP1a)蛋白稳定性的去泛素化酶,并探索其调控机制。方法通过去泛素化酶库筛选显著影响SREBP1a表达的去泛素化酶,免疫蛋白印记实验和实时荧光定量PCR(qRT-PCR)评估去泛素化酶对SREBP1a以及升脂基因表达的影响;通过红色荧光蛋白标记人源低密度脂蛋白(human Dil-low density lipoprotein,Human Dil-LDL)摄取和油红O染色等实验技术检测细胞摄取低密度脂蛋白(LDL)和脂质沉积情况。结果去泛素化酶库筛选发现泛素特异肽酶37(ubiquitin specific peptidase 37,USP37)可显著增加肝细胞SREBP1a蛋白表达水平,促进胆固醇摄取及脂质沉积。USP37基因敲除可显著降低SREBP1a蛋白表达水平,抑制升脂基因表达及脂质沉积。结论去泛素化酶USP37通过稳定SREBP1a蛋白表达,促进胆固醇摄取及脂质沉积,揭示了SREBP1a翻译后调控的新模式。
