亮氨酸拉链蛋白对前脂肪细胞增殖、分化及相关基因表达的影响

Effect of GILZ on preadipocytes proliferation,differentiation and related adipocytes gene expressions

目的:探讨亮氨酸拉链蛋白(GILZ)对3T3-L1前脂肪细胞增殖、分化的作用及对脂肪细胞分化相关标志基因PPARγ2、C/EBPa、LPL和FAS mRNA的表达。方法:采用MTT法检测GILZ稳定表达3T3-L1细胞从D1到D11细胞的增殖情况。油红O染色观察GILZ过表达对脂肪细胞分化和甘油三酯相对含量的影响。实时荧光定量PCR法检测脂肪细胞分化相关标志基因PPARγ2、C/EBPa、LPL和FAS的mRNA表达。结果:与转染Pc DNA3空载体的对照组相比,GILZ过表达组的细胞增殖差异无统计学意义(P>0.05)。经MID诱导后,与对照组相比,GILZ过表达组的桔红色细胞显著减少。脂肪细胞内甘油三酯相对含量也显著降低(0.365±0.012 vs 0.181±0.014,P<0.001)。分化过程中GILZ过表达的3T3-L1细胞内脂肪细胞分化基因PPARγ2、C/EBPa、LPL和FAS的mRNA表达显著降低(分化第9天时的相对表达分别为11.447±0.831 vs 1.173±0.290,17.700±0.915 vs 1.557±0.384,67.057±5.288 vs 9.467±3.406,40.946±3.968 vs 4.967±1.091,P<0.001)。结论:GILZ对前脂肪细胞的增殖没有明显的影响。GILZ过表达可显著性抑制PPARγ2,C/EBPa,LPL和FAS的mRNA表达,表明GILZ可能通过下调脂肪细胞分化转录因子PPARγ2,C/EBPa的表达而抑制脂肪细胞特异性基因LPL和FAS的表达,进而抑制脂肪细胞的分化。

Objective： To investigate the effect of glucocorticoid induced leucine zipper（ GILZ） on 3T3-L1 preadipocytes proliferation,differentiation and related mRNA expressions of the marker genes PPARg2,C /EBPa,LPL and FAS of adipocytes differentiation. Methods： Cell proliferation of 3T3-L1 cell clones of stable expression of GILZ between D1 and D11 was determined by MTT method. The effect of GILZ on adipocytes differentiation and the relative content of triglyceride were tested by with oil red-O staining. The related mRNA expressions of the marker genes PPARγ2,C / EBPa,LPL and FAS of adipocytes differentiation were measured by real-time fluorescence quantification PCR method. Results： Compared with the control group of transfected Pc DNA3 empty vector, there was no statistically statistical significance on cell proliferation in GILZ overexpression group（ P〉 0. 05）. After induced by MID,the orange-red cells in GILZ overexpression group greatly decreased compared with that in the control group. The relative content of triglyceride in adipocytes also significantly decreased（ 0. 365 ± 0. 012 vs 0. 181 ± 0. 014,P〈0. 001）. The mRNA expressions of PPARγ2,C /EBPa,LPL and FAS of adipocytes differentiated genes in 3T3-L1 cells of GILZ overexpression were significantly decreased during cell differentiation（ on the 9th day of cell differentiation,the relative expressions were 11. 447± 0. 831 vs 1. 173 ± 0. 290,17. 700 ± 0. 915 vs 1. 557 ± 0. 384,67. 057 ± 5. 288 vs 9. 467 ± 3. 406,40. 946 ± 3.968 vs 4. 967 ± 1. 091 respectively,P〈0. 001）. Conclusion： 1. GILZ has no significant effect on preadipocyte proliferation. 2. GILZ overexpression can significantly inhibit PPARγ2, C / EBPα, LPL and FAS mRNA expressions,indicating GILZ can inhibit adipocytes specific genes LPL and FAS expressions through downregulation of adipocytes differentiation transcription factors PPARγ2 and C / EBPα,so as to further inhibit adipocytes differentiation.