胰岛素样生长因子1对小鼠肺泡上皮细胞吞噬功能和白细胞介素10产生的影响

Effect of insulin-like growth factor 1 on phagocytosis and production of interleukin-10 in murine alveolar epithelial cells

目的·探讨胰岛素样生长因子1(insulin-like growth factor 1,IGF-1)对小鼠肺泡上皮细胞株MLE-12细胞吞噬功能和白细胞介素10(interleukin-10,IL-10)产生的影响。方法·体外培养的MLE-12细胞,在有或无磷脂酰肌醇-3-激酶(phosphatidylinositol-3-kinase,PI3K)抑制剂wortmannin存在下用IGF-1刺激48 h;加入荧光微球孵育2 h后,流式细胞术检测细胞吞噬荧光微球情况。酶联免疫吸附试验检测IGF-1刺激MLE-12细胞24 h后上清液中IL-10的含量。IGF-1预处理2 h后,脂多糖(lipopolysaccharides,LPS)刺激MLE-12细胞24 h,Western blotting检测细胞质中磷酸化信号转导与转录激活因子3(phosphorylated signal transduction and activator of transcription 3,p-STAT3)的表达情况。结果·随着IGF-1刺激浓度的增加,MLE-12细胞吞噬荧光微球的能力增强;在50 ng/mL的IGF-1的刺激下,MLE-12细胞吞噬荧光微球的能力达到峰值。wortmannin阻断PI3K/蛋白激酶B(Akt)途径,IGF-1促进MLE-12细胞吞噬荧光微球的能力消失。IGF-1促进MLE-12细胞分泌IL-10并抑制LPS诱导的STAT3激活。结论·IGF-1通过PI3K/Akt途径促进MLE-12细胞的吞噬作用,并具有一定的抗炎作用。

Objective · To investigate the effect of insulin-like growth factor 1 (IGF-1) on phagocytosis and production of interleukin-10 (IL-10) in the murine alveolar epithelial cell line MLE-12. Methods · After treatment with IGF-1 for 48 h, MLE-12 cells were incubated with fluorescent microspheres for 2 h in the presence or absence of wortmannin (phosphatidylinositol-3-kinase inhibitor). Flow cytometry was then used to assess cell phagocytosis of fluorescent microspheres. Enzyme linked immunosorbent assay (ELISA) was used to detect the content of IL-10 in MLE-12 cells culture supernatant stimulated by IGF-1 for 24 h. After pretreatment with IGF-1 for 2 h, MLE-12 cells were stimulated by lipopolysaccharides (LPS) for 24 h, and the expression of phosphorylated signal transduction and activator of transcription 3 (p-STAT3) in cytoplasm was detected by Western blotting. Results · With the increase of IGF-1 stimulation concentration, the ability of MLE-12 cells to phagocytose fluorescent microspheres increased, and the ability to phagocytose fluorescent microspheres reached the peak in the presence of IGF-1 at 50 ng/mL. However, the ability of IGF-1 to phagocytose fluorescent microspheres was completely blocked by wortmannin in MLE-12 cells. IGF-1 promoted IL-10 secretion and inhibited LPS-induced enhancement of STAT3 activation in MLE-12 cells. Conclusion · IGF-1 promotes phagocytosis of MLE-12 cells via the PI3K/protein kinase B (Akt) pathway and exhibits anti-inflammatory properties.