Visfatin在3T3-L1脂肪细胞诱导分化过程中的分泌变化及胰岛素的调节作用

Secretion of Visfatin during 3T3-L1 Preadipocyte Differentiation and Regulative Role of Insulin

目的观察3T3-L1前体脂肪细胞诱导分化过程中Visfatin蛋白分泌水平的变化,探讨胰岛素对脂肪细胞Visfatin分泌水平的调节作用。方法体外培养3T3-L1前体脂肪细胞,采用1-甲基-3-异丁基黄嘌呤(MIX)、胰岛素、地塞米松方案诱导3T3-L1前体脂肪细胞分化为成熟脂肪细胞,诱导分化过程中采用油红O染料鉴定并观察细胞分化情况。在诱导3T3-L1前体脂肪细胞分化成熟的不同时段(第0、4、6、8天)收集细胞培养上清液;并以100nmol/L胰岛素干预诱导分化第6、8天的成熟脂肪细胞,设未干预组为对照组,采用酶联免疫吸附法(ELISA)检测细胞培养上清液中Visfatin的蛋白水平。结果未诱导分化的3T3-L1前体脂肪细胞仅分泌低水平Visfatin蛋白[(29.0±2.4)μg/L],诱导分化后随3T3-L1脂肪细胞逐渐分化成熟,脂肪细胞培养上清液中Visfatin的蛋白水平逐渐升高,至分化第8天成熟脂肪细胞Visfatin分泌达到高峰[(48.0±3.4)μg/L]。以100nmol/L胰岛素干预第6天和第8天分化成熟的脂肪细胞后,细胞培养上清液Visfatin的蛋白水平均较对照组显著升高[(57.9±5.7)μg/Lvs(45.7±3.8)μg/L;(61.0±4.2)μg/Lvs(48.0±3.4)μg/LPa<0.05]。结论Visfatin蛋白分泌与脂肪细胞成熟度有关,胰岛素对脂肪细胞Visfatin的分泌可能具有正性调节作用。

Objective To observe the changes of the level of Visfatin protein secreted by 3T3 - L1 preadipocytes during adipocyte diffe- rentiation and to explore the regulative role of insulin on Visfatin secretion in adipocytes. Methods 3T3 - L1 preadipocytes were cultured in vitro and differentiated into the matured adipucytes with insulin,3 - isolbutyl - methyl xanthine （MIX） ,insulin and dexamethasone. Supernatant of cultured cells were collected at various stages of differentiation（0,4,6,8 day）. Oil red O dye was used to observe the the process of diffe- rentiation. The regulative role of insulin on Visfatin secretion in adipocytes was observed,lO0 nmol/L insulin was added into the cultured medium on Day 6 or Day 8 of differentiation. The levels of Visfatin in the supernatant of cuhured cells were detected by enzyme - linked immunosorbent assay （ELISA）. Results There was the gradually rising trend in the levels of Vistatin in the supernatant of cuhured cells during the diffe- rentiation of 3T3 - L1 preadipocyte. The secretion of Visfatin remained low [ （29.0 ± 2.4）μg/L in preadipocytes,and reached higher level [ （48.0 ± 3.4）μg/L] in fully differentiated adipocytes. Treatment of 100 nmoL/L insulin on adipocytes of Day 6 or Day 8 resulted in increased secretion of Visfatin by the matured adipocytes [ （57.9 ± 5.7 ） μg/L vs （45.7 ± 3.8 ） μg/L; （ 61.0± 4.2 ） μg/L vs （48.0 ± 3.4 ） μg/L P 〈 0.05 ]. Conclusions There is the relationship between the level of Visfatin secreted by adipocytes and adipocyte differentiation. Insulin may play the role of positive adjustment on the level of Visfatin secreted by adipocytes.