Pim-3在大鼠脂肪组织中的表达及其与脂肪胰岛素抵抗的关系

Relationship between insulin sensitivity and Pim-3 expression in rat adipose tissues

目的:检测Pim-3在脂肪中的表达,并探讨其在脂肪的胰岛素抵抗发生过程中的作用。方法:RT-PCR法检测脂肪组织中Pim-3 mRNA的表达,免疫荧光化学法检测Pim-3蛋白表达及亚细胞定位;检测胰岛素抵抗大鼠的附睾及肾周脂肪组织中Pim-3 mRNA表达变化;体外诱导大鼠骨髓间充质干细胞分化为脂肪细胞,油红O染色判断分化程度,并观察分化前后Pim-3表达变化。RT-PCR法检测高胰岛素(100 nmol/L)对骨髓间充质干细胞来源的脂肪细胞中Pim-3表达变化的影响。结果:(1)脂肪组织中具有较高水平的Pim-3 mRNA表达,免疫荧光结果显示其蛋白主要分布于胞浆;(2)胰岛素抵抗大鼠附睾及肾周脂肪组织中Pim-3 mRNA表达显著低于对照组(P<0.05);(3)大鼠骨髓间充质干细胞成功分化为脂肪细胞,分化后Pim-3 mRNA表达水平明显增高;(4)高胰岛素处理后,脂肪细胞中Pim-3 mRNA表达显著降低。结论:Pim-3表达于脂肪组织中,并可能参与骨髓间充质干细胞来源的脂肪细胞分化过程及脂肪组织胰岛素抵抗的发病过程。

AIM： To investigated the relationship between insulin sensitivity and Pim -3 expression in adipose tissues. METHODS ： The expression of Pim - 3 mRNA in adipocytes, epididymal and perirenal adipose tissues was analyzed by RT - PCR. The protein level and subcellular localization of Pim - 3 were determined by immunohistochemical assay. The rat mesenchymal stem cells （MSCs） were induced to differentiate into adipocytes in vitro. Adipogenic differentiation was confirmed by oil red 0 staining. MSC - derived adipocytes were pretreated with high concentration of insulin （ 100 nmol/L） and Pim-3 mRNA level was analyzed by RTPCR before and after differentiation. RESULTS： Pim -3 was highly expressed in insulin -sensitive tissues and cells. Pim -3 expression was reduced in visceral fatty tissues but not in skeletal muscles from rats with insulin resistance. The mRNA level of Pim - 3 was increased in matured adipocytes compared with non - differentiated bone marrow - derived MSCs. In addition, insulin treatment decreased mRNA expression of Pim - 3 in adipocytes. CONCLUSION： These results indicate that Pim - 3 may involve in the cellular metabolism of adipose tissues.