胰岛素样生长因子1对大鼠结肠平滑肌细胞中干细胞因子表达的影响

Insulin-like growth factor-1 upregulates the expression of stem cell factor in rat colonic smooth muscle cells

目的:探讨胰岛素样生长因子1(IGF-1)对大鼠结肠平滑肌细胞(SMC)表达干细胞因子(SCF)的影响.方法:酶解法分离培养SD大鼠结肠SMC、α-actin免疫荧光鉴定,然后将大鼠结肠SMC随机分为IGF-1不同浓度(0、5、10、50、100、150μg/L)、时间(0、8、16、24、48h)及IGF-1α受体(IGF-1Rα)抗体(0、50、100、150μg/L)干预组;Westernblot、RT-PCR法检测SMC合成SCF的变化.结果:低剂量IGF-1(5、10μg/L)对SCF蛋白和mRNA表达无影响(P>0.05),中高剂量IGF-1(50、100、150μg/L)诱导其表达增加(均P<0.05),100μg/L可能为体外最大有效浓度(0.820±0.061vs0.167±0.015;1.269±0.219vs0.560±0.023,均P<0.05),且其促SCF蛋白和mRNA合成的最高峰在第16小时(0.420±0.034vs0.209±0.001;1.407±0.133vs0.477±0.041,均P<0.05),IGF-1Rα抗体可抑制SCF蛋白和mRNA合成,抑制作用呈浓度依赖性(P<0.05).结论:IGF-1能通过作用于SMC上的IGF-1受体刺激大鼠结肠SMC内SCF的表达.

Abstract AIM： To investigate the effects of insulin-like growth factor-1 （IGF-1） on the expression of stem cell factor （SCF） in rat colonic smooth muscle cells （SMCs）. METHODS： Rat colonic SMCs were separated, cultured, and identified by immunofluorescence staining of α-actin. Cultured colonic SMCs were divided into IGF-1 treatment group and IGF-1 receptor antibody intervention group. Cells in the IGF-1 treatment group incubated with different concentrations （0, 5, 10, 50, 100 and 150 μg/L） of IGF-1 for different durations （0, 8, 16,24 and 48 hours）, while those in the IGF-1 receptor antibody intervention group were treated with IGF-1 and different concentrations of IGF-1 receptor monoclonal antibody （0, 50, 100 and 150 μg/L）. The expression of SCF in colonic SMCs was examined by Western blot and quantitative reverse transcription-polymerase chain reaction. RESULTS： Although IGF-1 at low concentrations （5 and 10 μg/L） had no significant impact on the expression of SCF mRNA and protein in SMCs （all P 〉 0.05）, IGF-1 at moderate or high concentrations （50, 100 and 150 μg/L） significantly upregulated the expression of SCF mRNA and protein （all P 〈 0.05）. The optimum concentration of IGF-1 to upregulate SCF expression in vitro was 100 μg/L （0.820 ± 0.061 vs 0.167 ± 0.015 and 1.269± 0.219 vs 0.560 ± 0.023, respectively; both P 〈 0.05）, and the peak expression of SCF occurred 16 hours after incubation with IGF-1 （0.420 ± 0.034 vs 0.209 ± 0.001 and 1.407±0.133 vs 0.477 ± 0.041, respectively; both P 〈 0.05）. IGF-1 receptor monoclonal antibody could inhibit the expression of SCF in SMCs in a dose-dependent manner （all P 〈 0.05）. CONCLUSION： IGF-1 can upregulate the expression of SCF in colonic SMCs perhaps in an IGF-1 receptor-dependent manner.