AIM To investigate the mechanism(s) by which potential effects of multi-drug highly-active antiretroviral therapy contributes to lipodystrophy syndrome. METHODS Preadipocytes from healthy donors were assessed for prol...AIM To investigate the mechanism(s) by which potential effects of multi-drug highly-active antiretroviral therapy contributes to lipodystrophy syndrome. METHODS Preadipocytes from healthy donors were assessed for proliferation and differentiation in the presence of nucleoside reverse transcriptase inhibitors(NRTIs), nonnucleoside reverse transcriptase inhibitors(NNRTIs), and protease inhibitors(PIs) individually and in combination. Effects on proliferation were assessed with a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay and effects on differentiation were assessed from glycerol-3-phosphate dehydrogenase(GPDH) activity and quantitation of Oil Red O staining for intracellular lipid. Data were analyzed with a randomized block ANOVA with post-hoc Fisher's Least Significant Difference test. RESULTS Preadipocyte proliferation was inhibited by a combination of NNRTI + NRTI(14% at 48 h, P < 0.001) and PI + NRTI(19% at 48 h, P < 0.001) with additional suppression when ritonavir(RTV) was added(26% at 48 h). The drug combination of atazanavir(ATV) + RTV + emtricitabine(FTC) + tenofovir(TDF) had the greatest inhibitory effect on proliferation at 48 h. Preadipocyte differentiation was most significantly reduced by the efavirenz + FTC + TDF assessed either by GPDH activity(64%) or lipid accumulation(39%), P < 0.001. Combining NRTIs with a PI(ATV + FTC + TDF) significantly suppressed differentiation(GPDH activity reduced 29%, lipid accumulation reduced by 19%, P < 0.01). This effect was slightly greater when a boosting amount of RTV was added(ATV + FTC + TDF + RTV, P < 0.001). CONCLUSION Although combination antiretroviral therapy is clinically more efficacious than single drug regimens, it also has a much greater inhibitory effect on preadipocyte proliferation and differentiation.展开更多
Objective:To evaluate anti-diabetic effect of Caulrpa kntillifera(C.lentillifera).Methods:The inhibitory effect of C.lentillifera extract on dipeptidyl peptidase-IV and a-glucosidase enzyme was measured in a cell free...Objective:To evaluate anti-diabetic effect of Caulrpa kntillifera(C.lentillifera).Methods:The inhibitory effect of C.lentillifera extract on dipeptidyl peptidase-IV and a-glucosidase enzyme was measured in a cell free system.Then,interleukin-1βand interferon-γinduced cell death and insulin secretion were measured in rat insulinoma(RIN)cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ELISA kit,respectively.Glucose uptake and glucose transporter expression were measured by fluorometry and western blotting,using 3T3-Ll adipocytes.Results:C.lentillifera extract significantly decreased dipeptidyl peptidase-IV and a-glucosidase enzyme activities,and effectively inhibited cell death and iNOS expression in interleukin-1βand interfcron-γinduced RIK cells.Furthermore,C.lntillifera extract significantly enhanced insulin secretion in RTN cells and glucose transporter expression and glucose uptake in 3T3-L1adipocytes.Conclusions:Thus,our results suggest that C.lentillifera could be used as a potential antidiabetic agenl.展开更多
Objective:To explore the effect of the protease inhibitor from Agaricus bisporus(J.E.Lange)Imbach(AbPI)on glucose uptake and oxidative stress in 3 T3-L1 adipocytes.Methods:Adipocytes were differentiated and stained wi...Objective:To explore the effect of the protease inhibitor from Agaricus bisporus(J.E.Lange)Imbach(AbPI)on glucose uptake and oxidative stress in 3 T3-L1 adipocytes.Methods:Adipocytes were differentiated and stained with OilRed-O staining to confirm adipogenesis.The toxic/protective effect of AbPI on the adipocytes was determined by MTT assay,intracellular reactive oxygen species generation through flow cytometry,and morphologically through confocal microscopy using propidium iodide,4,6-diamino-2-phenylindol dihydrochloride,and 2’,7’-dichlorofluorescein diacetate dyes.The uptake of fluorescent glucose analog,2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose by adipocytes was also studied through confocal microscopy.Results:MTT assay showed that the cell survival rate was(28.00±3.00)%,(92.33±2.60)%,and(71.34±2.10)%in the presence of 2 mM H2O2,AbPI alone,and AbPI and H2O2 both,respectively,in comparison to the control.Oil-Red-O staining indicated that Ab PI enhanced adipogenesis.AbPI stimulated the glucose uptake by adipocytes similar to the drug rosiglitazone,and showed insulinsensitizing effect in the presence of insulin,but failed to stimulate the uptake in the absence of insulin.Intracellular reactive oxygen species generation was reduced in differentiating adipocytes upon Ab PI treatment.Confocal microscopy showed that the damaged cell population rose to 3.50%,117.84%,and 261.50%in the presence of Ab PI alone,AbPI with H2O2,and H2O2 alone,respectively.Conclusions:The protease inhibitor enhances glucose uptake by adipocytes and exhibits a cytoprotective effect on them.展开更多
动脉粥样硬化是心血管疾病重要的病理生理基础,延缓和防治动脉粥样硬化对于减少和降低心血管疾病的发病率及病死率具有重要意义。高密度脂蛋白(high density lipoprotein,HDL)通过参与介导胆固醇逆向转运(reverse cholesterol transport...动脉粥样硬化是心血管疾病重要的病理生理基础,延缓和防治动脉粥样硬化对于减少和降低心血管疾病的发病率及病死率具有重要意义。高密度脂蛋白(high density lipoprotein,HDL)通过参与介导胆固醇逆向转运(reverse cholesterol transport,RCT)在抗动脉粥样硬化的形成和进展中发挥了重要作用。Preβ-1高密度脂蛋白(prebeta-1 high density lipoprotein,Preβ-1HDL)作为HDL的一种亚类,是外周细胞移出胆固醇的最初接受体,直接参与了RCT的起始步骤,并在随后的胆固醇酯化及转运中起着重要作用。本文就Preβ-1HDL的结构、代谢及其与心血管疾病的关系作一简要综述。展开更多
Dysregulation of microRNAs(miRNAs)in adipocytes plays a critical role in the pathogenesis of obesity.However,the signaling mechanisms regulating miRNAs production in adipose tissue remain largely unclear.Here,we show ...Dysregulation of microRNAs(miRNAs)in adipocytes plays a critical role in the pathogenesis of obesity.However,the signaling mechanisms regulating miRNAs production in adipose tissue remain largely unclear.Here,we show that adipose tissue-specific knockout of Ras homolog enriched in brain(Rheb),a direct upstream activator of mTOR,increases miR-182-5p level in mouse subcutaneous white adipose tissues.Interestingly,the inhibition of mTOR signaling by rapamycin has no effect on miR-182-5p level in primary subcutaneous white adipocytes,suggesting the presence of a mTOR-independent mechanism regulating Rheb-mediated miR-182-5p expression.Consistent with this view,Rheb-ablation activates the cAMP/PPARγsignaling pathway.In addition,treatment of white adipocytes with pioglitazone,a PPARγagonist,dramatically upregulates miR-182-5p levels.Our study reveals a unique mechanism by which Rheb regulates miR-182-5p in adipocytes.Given that increasing miR-182-5p in adipose tissue promotes beige fat development,our study also suggests a unique mechanism by which Rheb promotes thermogenesis and energy expenditure.展开更多
文摘AIM To investigate the mechanism(s) by which potential effects of multi-drug highly-active antiretroviral therapy contributes to lipodystrophy syndrome. METHODS Preadipocytes from healthy donors were assessed for proliferation and differentiation in the presence of nucleoside reverse transcriptase inhibitors(NRTIs), nonnucleoside reverse transcriptase inhibitors(NNRTIs), and protease inhibitors(PIs) individually and in combination. Effects on proliferation were assessed with a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay and effects on differentiation were assessed from glycerol-3-phosphate dehydrogenase(GPDH) activity and quantitation of Oil Red O staining for intracellular lipid. Data were analyzed with a randomized block ANOVA with post-hoc Fisher's Least Significant Difference test. RESULTS Preadipocyte proliferation was inhibited by a combination of NNRTI + NRTI(14% at 48 h, P < 0.001) and PI + NRTI(19% at 48 h, P < 0.001) with additional suppression when ritonavir(RTV) was added(26% at 48 h). The drug combination of atazanavir(ATV) + RTV + emtricitabine(FTC) + tenofovir(TDF) had the greatest inhibitory effect on proliferation at 48 h. Preadipocyte differentiation was most significantly reduced by the efavirenz + FTC + TDF assessed either by GPDH activity(64%) or lipid accumulation(39%), P < 0.001. Combining NRTIs with a PI(ATV + FTC + TDF) significantly suppressed differentiation(GPDH activity reduced 29%, lipid accumulation reduced by 19%, P < 0.01). This effect was slightly greater when a boosting amount of RTV was added(ATV + FTC + TDF + RTV, P < 0.001). CONCLUSION Although combination antiretroviral therapy is clinically more efficacious than single drug regimens, it also has a much greater inhibitory effect on preadipocyte proliferation and differentiation.
基金Supported by the Ministry of Education.Science and Technology (Grant No.2012RTAL2009172)
文摘Objective:To evaluate anti-diabetic effect of Caulrpa kntillifera(C.lentillifera).Methods:The inhibitory effect of C.lentillifera extract on dipeptidyl peptidase-IV and a-glucosidase enzyme was measured in a cell free system.Then,interleukin-1βand interferon-γinduced cell death and insulin secretion were measured in rat insulinoma(RIN)cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ELISA kit,respectively.Glucose uptake and glucose transporter expression were measured by fluorometry and western blotting,using 3T3-Ll adipocytes.Results:C.lentillifera extract significantly decreased dipeptidyl peptidase-IV and a-glucosidase enzyme activities,and effectively inhibited cell death and iNOS expression in interleukin-1βand interfcron-γinduced RIK cells.Furthermore,C.lntillifera extract significantly enhanced insulin secretion in RTN cells and glucose transporter expression and glucose uptake in 3T3-L1adipocytes.Conclusions:Thus,our results suggest that C.lentillifera could be used as a potential antidiabetic agenl.
文摘Objective:To explore the effect of the protease inhibitor from Agaricus bisporus(J.E.Lange)Imbach(AbPI)on glucose uptake and oxidative stress in 3 T3-L1 adipocytes.Methods:Adipocytes were differentiated and stained with OilRed-O staining to confirm adipogenesis.The toxic/protective effect of AbPI on the adipocytes was determined by MTT assay,intracellular reactive oxygen species generation through flow cytometry,and morphologically through confocal microscopy using propidium iodide,4,6-diamino-2-phenylindol dihydrochloride,and 2’,7’-dichlorofluorescein diacetate dyes.The uptake of fluorescent glucose analog,2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose by adipocytes was also studied through confocal microscopy.Results:MTT assay showed that the cell survival rate was(28.00±3.00)%,(92.33±2.60)%,and(71.34±2.10)%in the presence of 2 mM H2O2,AbPI alone,and AbPI and H2O2 both,respectively,in comparison to the control.Oil-Red-O staining indicated that Ab PI enhanced adipogenesis.AbPI stimulated the glucose uptake by adipocytes similar to the drug rosiglitazone,and showed insulinsensitizing effect in the presence of insulin,but failed to stimulate the uptake in the absence of insulin.Intracellular reactive oxygen species generation was reduced in differentiating adipocytes upon Ab PI treatment.Confocal microscopy showed that the damaged cell population rose to 3.50%,117.84%,and 261.50%in the presence of Ab PI alone,AbPI with H2O2,and H2O2 alone,respectively.Conclusions:The protease inhibitor enhances glucose uptake by adipocytes and exhibits a cytoprotective effect on them.
文摘动脉粥样硬化是心血管疾病重要的病理生理基础,延缓和防治动脉粥样硬化对于减少和降低心血管疾病的发病率及病死率具有重要意义。高密度脂蛋白(high density lipoprotein,HDL)通过参与介导胆固醇逆向转运(reverse cholesterol transport,RCT)在抗动脉粥样硬化的形成和进展中发挥了重要作用。Preβ-1高密度脂蛋白(prebeta-1 high density lipoprotein,Preβ-1HDL)作为HDL的一种亚类,是外周细胞移出胆固醇的最初接受体,直接参与了RCT的起始步骤,并在随后的胆固醇酯化及转运中起着重要作用。本文就Preβ-1HDL的结构、代谢及其与心血管疾病的关系作一简要综述。
基金supported by grants 82170886 and 81800758 from the National Nature Science Foundation of Chinapartially supported by the Fundamental Research Funds for the Central Universities of Central South University(2021zzts1048)。
文摘Dysregulation of microRNAs(miRNAs)in adipocytes plays a critical role in the pathogenesis of obesity.However,the signaling mechanisms regulating miRNAs production in adipose tissue remain largely unclear.Here,we show that adipose tissue-specific knockout of Ras homolog enriched in brain(Rheb),a direct upstream activator of mTOR,increases miR-182-5p level in mouse subcutaneous white adipose tissues.Interestingly,the inhibition of mTOR signaling by rapamycin has no effect on miR-182-5p level in primary subcutaneous white adipocytes,suggesting the presence of a mTOR-independent mechanism regulating Rheb-mediated miR-182-5p expression.Consistent with this view,Rheb-ablation activates the cAMP/PPARγsignaling pathway.In addition,treatment of white adipocytes with pioglitazone,a PPARγagonist,dramatically upregulates miR-182-5p levels.Our study reveals a unique mechanism by which Rheb regulates miR-182-5p in adipocytes.Given that increasing miR-182-5p in adipose tissue promotes beige fat development,our study also suggests a unique mechanism by which Rheb promotes thermogenesis and energy expenditure.
