支链氨基酸通过Stat3通路双向调控3T3-L1前脂肪细胞分化  

Dual effects of branched-chain amino acid on differentiation of 3T3-L1 preadipocytes through Stat3 pathway

作　　者：蔡兴华 高洁 徐媛颖 张会会 买热艳木·肉孜 沙雯君 鲁郡 雷涛 Cai Xinghua;Gao Jie;Xu Yuanying;Zhang Huihui;Maireyanmu Rouzi;Sha Wenjun;Lu Jun;Lei Tao(Shanghai Putuo Central School of Clinical Medicine,Anhui Medical University,Shanghai 200062;The Fifth School of Clinical Medicine,Anhui Medical University,Hefei 230032;Dept of Endocrinology,Putuo Hospital,Shanghai University of Traditional Chinese Medicine,Shanghai 200062)

机构地区：[1]安徽医科大学上海普陀中心临床学院,上海200062 [2]安徽医科大学第五临床医学院,合肥230032 [3]上海中医药大学附属普陀医院内分泌科,上海200062

出　　处：《安徽医科大学学报》2025年第3期494-501,共8页Acta Universitatis Medicinalis Anhui

基　　金：国家自然科学基金项目(编号:81774083);上海市普陀区卫生健康系统临床特色专科建设项目(编号:2020tszk01);上海市卫生健康委员会课题(编号:202240309);上海市普陀区卫生健康系统科技创新项目(编号:ptkwws202003、ptkwws202302)。

摘　　要：目的 探讨不同浓度支链氨基酸(BCAA)对3T3-L1前体脂肪细胞分化的作用及其机制。方法 将3T3-L1前体脂肪细胞分为空白对照(Control)组、分化介质(DM)组、低浓度BCAA组和高浓度BCAA组;CCK-8法检测不同浓度BCAA对前脂肪细胞存活率的影响;油红O染色观察各组脂肪细胞脂滴形成情况;酶法检测细胞内三酰甘油(TG)和总胆固醇(TC)含量;RT-qPCR和Western blot检测Stat3和脂肪细胞分化相关基因mRNA和蛋白表达情况。结果 CCK-8结果显示,当BCAA浓度≤10 mmol/L时,3T3-L1细胞的存活率不受BCAA的影响。与DM组相比,低浓度BCAA组(0.5、1.0 mmol/L)细胞内脂滴明显增大、脂滴数目明显增加,且细胞内TC(0.88 vs 0.68 mmol/g;0.83 vs 0.68 mmol/g,P<0.01)和TG水平(0.77 vs 0.40 mmol/g;0.62 vs 0.40 mmol/g,P<0.01)明显上升;而高浓度BCAA组(5.0、10.0 mmol/l)细胞分化较DM组明显下降。RT-qPCR和Western blot检测显示低浓度BCAA组PPARγ、C/EBPα、Adiponectin、FABP4的mRNA和蛋白表达均明显上升,而高浓度BCAA组上述基因表达均明显下降(P<0.01)。此外,低浓度BCAA促进Stat3磷酸化水平,而高浓度BCAA抑制其磷酸化水平(P<0.01)。结论 BCAA通过Stat3双向调控前脂肪细胞脂肪分化,即低浓度BCAA可通过促进Stat3磷酸化水平诱导其向成熟脂肪细胞分化;而高浓度BCAA则抑制Stat3磷酸化及细胞分化。Objective To investigate the effects of branched-chain amino acid(BCAA)on the differentiation of 3T3-L1 preadipocytes and its potential mechanism.Methods 3T3-L1 preadipocytes were divided into the Control,differentiation medium(DM),low-concentration BCAA,and high-concentration BCAA groups.A CCK-8 assay was utilized to evaluate pre-adipocyte survival under various BCAA concentrations.Oil-red O staining was used to observe the formation of lipid droplets in adipocytes.Intracellular triglyceride(TG)and total cholesterol(TC)were detected by enzymatic method.RT-qPCR and Western blot were used to detect the mRNA and protein expression of Stat3 and adipocyte differentiation-related genes.Results CCK-8 results showed that the viability of 3T3-L1 cells was not affected when the BCAA concentration was≤10 mmol/L.Compared with the DM group,the low-concentration BCAA groups(0.5 and 1.0 mmol/L)had significantly larger intracellular lipid droplets,increased number of lipid droplets,and elevated levels of the intracellular TC(0.88 vs 0.68 mmol/g;0.83 vs 0.68 mmol/g,P<0.01)and TG(0.77 vs 0.40 mmol/g;0.62 vs 0.40 mmol/g,P<0.01).Nevertheless,the cell differentiation in the high-concentration group(5.0 and 10.0 mmol/L)significantly decreased compared with that in the DM group.Further,levels of PPARγ,C/EBPα,Adiponectin,and FABP4 mRNA and protein expression significantly increased in the low-concentration group,but significantly decreased in the high-concentration group than that in the DM group(P<0.01).In addition,low concentrations of BCAA promoted stat3 phosphorylation,while high concentrations inhibited its phosphorylation(P<0.01).Conclusion BCAA have a dual role in regulating the differentiation of preadipocytes through Stat3,i.e.low concentrations of BCAA induce cell differentiation by promoting Stat3 phosphorylation;whereas high concentrations of BCAA inhibit Stat3 phosphorylation and cell differentiation.

关 键 词：BCAA 3T3-L1 脂肪细胞分化 STAT3 脂肪生成 肥胖 

分 类 号：R589.2[医药卫生—内分泌]