促酰化蛋白促进脂肪细胞分化过程中的克隆增殖

目的　观察促酰化蛋白 (ASP)对 3T3 L1前脂肪细胞的分化过程中克隆增殖的影响 ,以进一步探讨ASP诱导前脂肪细胞分化的可能机制。方法　采用3 H胸腺嘧啶掺入法和MTT法分别检测ASP诱导 3T3 L1前脂肪细胞分化过程中DNA合成量及细胞增殖的情况 ,并采用流式细胞术检测诱导分化后细胞周期构成的变化。结果　①ASP组在诱导分化 2 4h时 ,DNA合成量明显增加 ,与对照组相比差异有极显著性意义 (P <0 0 1) ,在 4 8h和 72h时DNA合成量降低 ,与对照组相比差异无显著性意义 (P >0 0 5 )。②诱导分化 2 4h时 ,ASP组细胞增殖明显 ,与对照组相比差异有显著性意义 (P <0 0 5 ) ;诱导分化 4 8h、 72h时 ,ASP组细胞增殖不明显。③ASP组可促进处于生长停滞期的前脂肪细胞重新进入细胞周期 ,G0 /G1期细胞减少 ,S期的细胞明显增多 ,细胞处于分裂增殖状态。结论　诱导分化过程中 ,ASP可促进 3T3 L1前脂肪细胞发生克隆增殖。ASP促进细胞克隆增殖的作用 ,可能是其诱导前脂肪细胞分化的分子机制之一。

Differentiating 3T3-L1 Preadipocytes Undergo Clonal Expansion Induced by Acylation Stimulating Protein

Objective To study mitotic clonal expansion during differentiation of 3T3-L1 preadipocytes induced by acylation stimulating protein (ASP). Methods The DNA synthesis was detected by 3H-TdR incorporation method and cell proliferation was detected by MTT colorimetric assay. The cell cycle was analyzed by flow cytometry technique. Results DNA synthesis was increased significantly after 3T3-L1 preadipocytes were induced by ASP for 24 h in ASP group as compared with that in control group (P<0.01). There was no significant difference in DNA synthesis between ASP group and control group after 3T3-L1 preadipocytes were induced by ASP for 48 h and 72 h (P>0.05). The proliferation of the 3T3-L1 preadipocytes was increased significantly after they were induced by ASP for 24 h in ASP group as compared with that in control group (P<0.05). After 3T3-L1 preadipocytes were induced by ASP for 48 h and 72 h, no significant proliferation was found in ASP group. ASP could promote the 3T3-L1 preadipocytes in growth arrest to enter into new cell cycle. The cells were pushed into S phase from G 0/G 1 phase and the cells were proliferated. Conclusion ASP can stimulate the preadipocytes to develop clonal expansion during the differentiation, which may be one of the mechanisms by which ASP induced preadipocytes to differentiation.