瘦素促进低氧状态下大鼠气道平滑肌细胞增殖及HIF-1α、NF-κB表达

Leptin promotes the proliferation of airway smooth muscle cells and the expressions of HIF-1α and NF-κB of hypoxic rats

目的研究瘦素对低氧状态下大鼠气道平滑肌细胞(ASMC)增殖及缺氧诱导因子1α(HIF-1α)、核因子-κB(NF-κB)表达的影响。方法分常氧、低氧2种状态体外培养大鼠ASMC,按随机数字表法将低氧组细胞分为低氧组、50μg/L瘦素联合低氧组(L50组)、100μg/L瘦素联合低氧组(L100组)、200μg/L瘦素联合低氧组(L200组)、200μg/L瘦素联合低氧和瘦素受体抗体组(ob-R抗体组)。各组均孵育24 h,CCK-8法检测细胞增殖率,反转录PCR检测HIF-1α、NF-κB的mRNA的表达,Western blot法检测HIF-1α、NF-κB的蛋白表达。结果与常氧组相比,各低氧组细胞增殖活性明显增强;与低氧组相比,L50、L100、L200组细胞增殖活性增强,并与浓度呈正相关(r=0.992);与L50、L100、L200组相比,ob-R抗体组细胞增殖明显降低。与常氧组相比,各低氧组HIF-1α、NF-κB的mRNA及蛋白表达增加;与低氧组相比,L50、L100、L200组HIF-1α、NF-κB的mRNA及蛋白表达增加,并与浓度呈正相关;与L50、L100、L200组相比,ob-R抗体组HIF-1α、NF-κB的mRNA及蛋白表达降低。结论瘦素能促进低氧状态下ASMC增殖,并且能够促进HIF-1α、NF-κB的表达。

Objective To investigate the effect of leptin on the proliferation of airway smooth muscle cells （ASMCs） and the expressions of hypoxia-inducible factor-1α （HIF-1α） and nuclear factor-kappa B （NF-κB） of hypoxic rats. Methods The rat ASMCs were cultured under normoxic and hypoxic states. The hypoxic cells were divided into hypoxia group, leptin 50 μg/L hypoxia group （ L50 group）, leptin 100 μg/L hypoxia group （ L100 group）, leptin 200 μg/L hypoxia group （ L200 group）, leptin 200 μg/L and leptin receptor antibody hypoxia group （ob-R antibody group） by random number table. All the groups are cultured for 24 hours. Then the CCK-8 method was used to assay cell proliferation rate, and Western blotting and real-time RT-PCR to measure the expressions of HIF-1α and NF-KB at protein and mRNA levels. Results Compared with the normoxic group, each hypoxia group had significantly increased cell proliferation. Compared with the hypoxia group, cell proliferation rate was significantly raised in L50, L100 and L200 groups, and it was positively correlated with the concentration （r=0. 992）. Compared with L50, L100 and L200 groups, the ob-R antibody group showed significantly decreased cell proliferation rate. Compared with the normoxic group, each hypoxic group has increased expressions of HIF-1α and NF-KB mRNA and proteins; compared with the hypoxia group, the expressions were significantly elevated in the L50, L100 and L200 groups and showed a positive correlation with the concentration; but the expressions were reduced in the ob-R antibody group as compared with L50, L100 and L200 groups. Conclusion Leptin can promote rat ASMCs proliferation and the expressions of HIF-1α and NF-κB under hypoxic condition.