维甲酸对软骨细胞的凋亡及其IGFBP-6表达的影响

Up-regulation of retinoic acid induces on cell apoptosis and expression of IGFBP-6 in chondrocyte

目的探讨维甲酸对软骨细胞凋亡功能的影响及细胞内胰岛素样生长因子结合蛋白6(insulin-like growthfactor binding protein 6,IGFBP-6)的表达规律。方法胰酶消化法体外培养兔的软骨细胞;全反式维甲酸(ATRA)作用软骨细胞株;细胞免疫化学观察软骨细胞中Ⅱ型胶原的合成和分泌变化;流式细胞仪检测软骨细胞株细胞凋亡率;采用RT-PCR半定量分析软骨细胞中IGFBP-6 mRNA的表达;应用Western印迹杂交鉴定软骨细胞中IGFBP-6蛋白质的表达。结果1×10-6mol/L剂量的ATRA作用软骨细胞24 h,ATRA抑制了软骨细胞中Ⅱ型胶原的分泌;1×10-6mol/L剂量的ATRA使软骨细胞凋亡率增加250%,出现明显亚二倍体峰(凋亡细胞峰),差异有统计学意义(P<0.05);ATRA使软骨细胞中IGFBP-6 mRNA和蛋白质的表达分别增加了128%和195%,差异有统计学意义(P<0.05)。结论维甲酸负性调节软骨细胞分泌功能,促进软骨细胞凋亡;维甲酸可能通过调控靶基因IGFBP-6的基因转录和翻译,发挥对软骨细胞的促凋亡作用。

Objective To investigate the effect of retinoic acid（RA） on cell apoptosis and gene regulation of insulin-like growth factor binding protein 6（IGFBP-6） in rat chondrocyte.Methods Chondrocyte from rat were cultured with all trans retinoic acid（ATRA） at 1×10^-6 mol/L for 24 hours.The cell immunochemistry method and flow cytometry were used to measure the 2-collagenous and the cell apoptosis in ATRA-treated chondrocyte;The IGFBP-6 mRNA and protein level in chondrocyte were detected by Reverse Transcription Polymerase Chain Reaction（RT-PCR） and Western blotting analysis.Results The 2-collagenous in chondrocyte were down-regulated by ATRA at 1×10^-6 mol/L.The cell apoptosis in chondrocyte exposed to ATRA at 1×10^-6 mol/L increased 250%,compared with control group （P〈0.05）.The IGFBP-6 mRNA and protein level in ATRA-treated chondrocyte were increased 128% and 195%,respectively（P〈0.05）.Conclusion Retinoic acid may be down-regulated the secretion and cell proliferation,but up-regulated the cell apoptosis of chondrocyte in vitro.Retinoic acid may possess the up-regulation on cell apoptosis through the effect on genetic transcription and translation of IGFBP-6.