大鼠髁突软骨细胞凋亡与胰岛素样生长因子1的影响

背景：胰岛素样生长因子1参与了髁突软骨生长与改建，是软骨发育关键因子。 目的：探索胰岛素样生长因子1对体外培养大鼠髁突软骨细胞凋亡的作用，以及对凋亡相关因子Bcl-2和Bax mRNA及蛋白表达变化的影响。 方法：体外培养并鉴定出生后1，28 d大鼠髁突软骨细胞后，将每个年龄组的髁突软骨细胞分别分为实验组和对照组。饥饿培养24 h后，实验组加入100 μg/L重组大鼠胰岛素样生长因子1细胞因子孵育48 h，对照组正常培养。 结果与结论：与对照组相比，实验组加入重组胰岛素样生长因子1后，髁突软骨细胞数量增多，增殖速度显著增加(P < 0.05)。实时PCR和Western blot检测显示，加入重组胰岛素样生长因子1培养48 h后，各组髁突软骨细胞中bcl-2 mRNA和蛋白表达增加，bax mRNA和蛋白表达减少(P < 0.05)。 提示胰岛素样生长因子1可以促进新出生及青春期大鼠髁突软骨细胞增殖，抑制其凋亡，并可能通过Bcl-2和Bax介导抑制凋亡。

Insulin-like growth factor 1 affects the apoptosis of rat condylar chondrocytes

BACKGROUND: Insulin-like growth factor 1 is the key factor during cartilage development, which is involved in the growth and reconstruction of condylar cartilage. OBJECTIVE: To study the effect of insulin-like growth factor 1 on cell apoptosis and the apopotosis-associated factors of Bcl-2, Bax mRNA and protein expressions of rat condylar chondrocytes. METHODS:The 1-day-old and 28-day-old rat condylar chondrocytes were cultured and identified in vitro. The condylar chondrocytes with different ages were divided into experimental group and control group. After being starved for 24 hours, chondrocytes in the experimental group were incubated with 100 μg/L recombined rat insulin-like growth factor 1 for 48 hours, while the chondrocytes in the control group were incubated normally. RESULTS AND CONCLUSION: Compared with the control group, after being incubated with recombined insulin-like growth factor 1, the number of condylar chondrocytes was increased with high speed proliferation (P < 0.05). Real-time RCR and western blot analysis revealed that the expression levels of Bcl-2 mRNA and protein were increased after added with recombined rat insulin-like growth factor 1, while the expression levels of Bax and protein were decreased (P < 0.05). The results indicate that insulin-like growth factor 1 can promote the proliferation and reduce cell apoptosis of newborn and adolescent rat condylar chondrocytes, which may be mediated by Bcl-2 and Bax.