促酰化蛋白(ASP)诱导3T3-L1前脂肪细胞分化

Acylation Stimulating Protein Inducing 3T3-L1 Preadipocyte Differentiation

促酰化蛋白 (ASP)代替经典激素“鸡尾酒”诱导法中胰岛素 ,通过形态学观察、油红染色分化百分比测定、脂肪细胞甘油三酯合成率和甘油三酯总量测定 ,并与经典激素“鸡尾酒”法诱导前脂肪细胞分化情况比较 ,探讨ASP是否具有诱导 3T3 L1前脂肪细胞分化作用 .ASP组诱导分化第 6d ,3T3 L1前脂肪细胞变大、变圆 ,出现大量脂肪滴 ,形态由前脂肪细胞向成熟脂肪细胞转变 ;随着诱导分化时间延长 ,胞浆中脂滴进一步积累 .分化 9d时 ,3T3 L1前脂肪细胞分化完全 .油红染色结果显示 ,ASP组分化率很高 (85 % ) ,与胰岛素组分化率 (90 % )相似 ,明显高于IBMX +DEX组 (4 0 % ) .ASP不仅促进 3T3 L1前脂肪细胞形态向成熟脂肪细胞转化 ,同时促进细胞中甘油三酯的合成和积累 .ASP组诱导分化第 3d时 ,脂肪细胞甘油三酯合成率明显高于对照组和IBMX +DEX组 ,但仍低于胰岛素组 ;在分化第 6d和第 9d时 ,ASP组甘油三酯合成率进一步升高 ,与对照组和IBMX +DEX组相比差异有极显著性 ,与胰岛素组相比无显著性差异 .ASP组诱导分化 3d时 ,脂肪细胞中甘油三酯总量明显高于对照组和IBMX +DEX组 ;分化 6d和 9d时 ,甘油三酯总量进一步升高 ,与对照组和IBMX +DEX组相比差异有极显著性 ,而与胰岛素组相比无显著性差异 .结果表明 。

Acylation stimulating protein(ASP) is an adipocyte derived protein which has potent anabolic effects on adipocyte for both glucose and free fatty acid storage. ASP has a strong effect on the diacylglycerol acyltransferase and stimulates triglyceride synthesis. Based on these biological actions of ASP, ASP may induce preadipocytes to differentiation. ASP, IBMX and DEX (ASP group) was used to induce 3T3 L1 preadipocytes to differentiation. The morphological changes was observed and the differentiation rate was assayed by Oil Red O staining. On the other hand, TG synthesis was assayed by 3H oleic acid incorporation rate and TG mass was detected by chemical colorimetry methods. These results were compared with that of the differentiation in 3T3 L1 preadipocytes induced by insulin, IBMX and DEX( insulin group) and only IBMX and DEX (IBMX+DEX group) to study the role of ASP on the differentiation of 3T3 L1 preadipocytes. There were a lot of fat drops in 3T3 L1 cells and these cells became bigger and rounder on the 6th day induced by ASP group. With time gone, more and more fat drops accumulated in these cells. These morphological changes of 3T3 L1 cells were very similar to that of 3T3 L1 cells induced by insulin group. In IBMX +DEX group, there were a few fat drops in the cells. On the 9th day induced by ASP group,the cells had high differentiation rate (85%). It was just as that induced by insulin group (90%). Both of thesee were higher than that of IBMX +DEX group (40%). On the 3th day after inducing by ASP group, TG synthesis and TG mass in 3T3 L1 cells were significantly increased compared with that of control group and IBMX+DEX group, but there were still significant differences between ASP group and insulin group. On the 6th day and 9th day after inducing by ASP group, there were significantly increased in TG synthesis and TG mass in 3T3 L1 cells, compared with control group and IBMX+DEX group. But there was no significant difference compared with insulin group. As a new adipocytes hormone, ASP can induce preadipocytes to differentiation.