瘦素对人前脂肪细胞增殖及分化的影响

Effects of leptin on proliferation and differentiation of human preadipocyte

目的 观察瘦索在体外对人前脂肪细胞增殖和分化的影响,探讨瘦素调节肥胖发生的可能机制.方法 分离并体外培养人腹部皮下前脂肪细胞.采用3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐（MTT）比色法、细胞计数法、油红O染色提取法及逆转录-聚合酶链式反应（RT-PCR）方法 分析不同浓度（0～1 000 ng/ml）瘦素对人前脂肪细胞增殖、脂质积聚及分化转录因子γ2过氧化物酶体增殖物激活受体（PPAR-γ）、CCAAT增强子α结合蛋白（C/EBP-α）mRNA表达的影响.结果 高浓度（1 000 ng/ml）瘦素能够促进人前脂肪细胞的增殖、脂质积聚以及PPAR-γ2、C/EBP-α mRNA表达（P〈0.05）.低浓度（10 ng/ml）和中浓度（100 ng/ml）瘦素对人前脂肪细胞的增殖及脂质积聚没有明显的促进作用（P〉0.05）.结论 在体外超生理浓度的瘦素能够促进前脂肪细胞的增殖和分化,提示瘦素抵抗、血清高瘦素浓度等病理状态时,瘦素可能促进前脂肪细胞的增殖及分化,影响肥胖发生.

Objective To observe the effects of leptin on the proliferation and differentiation of human preadipocyte in vitro, and to explore the possible mechanism of the generation of obesity regulated by leptin. Methods The human preadipocytes were isolated from human subcutaneous adipose tissue of abdomen and cultured in vitro. The effects of leptin （0-1 000 ng/ml） on the proliferation, lipid accumulation and the mRNA expression of PPAR-γ2 and C/EBP-α, which are the differentiation and transcription factor of human preadipocyte, were analyzed by the methods of MTT, cell counting, extracting stained intracytoplasmic lipid with oil red O and RT-PCR. Results Leptin （1 000 ng/ml） could stimulate the proliferation, lipid accumulation and the mRNA expression of PPAR-γ2 and C/EBP-α （P〈0. 05）. There were not obvious effects on the proliferation and lipid accumulation in the groups of lower （10 ng/ml） and common （100 ng/ml） concentration （P〉0. 05）. Conclusion Leptin in higher concentration can stimulate the proliferation and differentiation of preadipocye in vitro, which indicates that leptin may regulate the generation of obesity through acting on the proliferation and differentiation of preadipocyte at the pathologic state of leptin resistance and high leptin concentration in serum.