Ⅰ型胶原对脂肪细胞分化的影响及其分子机制初探

摘要

目的 观察不同浓度的Ⅰ型胶原(type Ⅰ collagen,Col Ⅰ)对3T3-L1前脂肪细胞诱导分化为成熟脂肪细胞的影响,初步分析其可能的作用机制.方法 3T3-L1前脂肪细胞诱导分化过程中加入不同浓度的Ⅰ型胶原:①采用MTT法检测3T3-L1前脂肪细胞的增殖；②油红O染色法观察分化成熟脂肪细胞形态学变化；③免疫印迹法测定脂肪细胞分化转录因子过氧化物酶体增殖物激活受体γ(peroxisome proliferators-activated receptorγ,PPARγ)和CCAAT增强子结合蛋白α(CCAAT/enhan-cer-binding proteinα,C/EBPα)蛋白表达水平.结果 不同浓度Ⅰ型胶原干预后,各组3T3-L1前脂肪细胞的增殖与对照组比无显著变化.随着Ⅰ型胶原浓度升高,油红O染色逐渐变浅,提示分化成熟的脂肪细胞逐渐减少.脂肪细胞分化转录因子PPARy和C/EBPα的蛋白表达水平逐渐降低,呈剂量依赖性,且浓度为10-5mol/L和10-4mol/L时与对照组比较差异有统计学意义(P＜0.05).结论 Ⅰ型胶原在本实验中不影响3T3-L1前脂肪细胞增殖,但呈剂量依赖性抑制其向成熟脂肪细胞分化,下调脂肪细胞分化转录因子PPARγ和C/EBPα的表达可能是其作用机制之一.%Objective To study the effect of different concentration of type Ⅰ collagen (Col Ⅰ) on 3T3-L1 pre-adipocytes differentiated into mature adipocytes and the underlying molecular mechaninsms.Methods During the process of 3T3-L1 pre-adipocytes differentiation,we added different concentration of type Ⅰ collagen.①The proliferation of 3T3-L1 pre-adipocytes was detected by MTT methods.②Through Oil Red O staining,we observed the morphological of mature adipocytes.③We used western blot to detect the expression of transcription factors of peroxisome proliferators-activated receptorγ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα) after 3T3 -L1 pre-adipocytes differentiation.Results Different concentration of type Ⅰ collagen did not affect the proliferation of 3T3-L1 preadipocytes compared with the control.With the increased concentration of type Ⅰ collagen,Oil Red O staing gradually became shallow suggesting that mature adipocytes gradually decreased.The expression of transcription factors PPARγ and C/EBPα were gradually decreased in a dose -dependent manner,and significantly when the concentrations of type Ⅰ Collagen were 10-5 mol/L and 10-4 mol/L respectively(P ＜ 0.05).Conclusion type Ⅰ collagen did not affect the proliferation of 3T3-L1 pre-adipocyte,but it could inhibit adipogenesis of 3T3-L1 preadipocytes with dose-dependent,manner and decrease the expression of PPARγ and C/EBPα protein levels.