胰岛素样生长因子结合蛋白4基因对内皮细胞衰老的调节作用

Effects of Insulin-like Growth Factor Binding Protein-4 on Vascular Endothelial Cell Senescence

目的探讨胰岛素样生长因子结合蛋白4(IGFBP4)对血管内皮细胞衰老进程的影响。方法分离培养的人脐静脉内皮细胞(HUVEC)并构建传代性衰老模型,分别将过表达IGFBP4、沉默IGFBP4表达的慢病毒及空载慢病毒转染HUVEC,结合光镜、β-半乳糖苷酶活性测定及细胞周期测定等方法观察各组细胞传代过程中的衰老现象。结果慢病毒感染细胞后,过表达组[IGFBP4(+)组]内皮细胞传代代数较空载病毒组(对照组)和IGFBP4基因沉默组[IGFBP4(-)组]明显增加[14.33±0.67比9.67±0.33、10.67±0.33;P<0.05];实验中各代细胞IGFBP4(+)组衰老率均低于对照组和IGFBP4(-)组[以第6代为例,分别为(24.60±0.90)%比(34.92±0.92)%、(33.74±0.62)%,P<0.05];随传代代龄增加,高代龄细胞(第6代)较低代龄细胞(第2代)降低的细胞增殖指数IGFBP4(+)组均低于对照组和IGFBP4(-)组[(10.35±0.57)%比(14.90±0.85)%、(13.99±0.65)%,P<0.05];各组实验在对照组与IGFBP4(-)组间比较差异无统计学意义。结论提高IGFBP4的表达能够延缓血管内皮细胞的衰老进程。

Aim To investigate the effects of insulin-like growth factor binding protein-4( IGFBP4) on vascular endothelial cell senescence. Methods Human umbilical vein endothelial cells( HUVEC) were cultured in vitro. A HUVEC aging model was established through cell passaging. Lentivirus expressing IGFBP4 or si-IGFBP4,and empty vector transfected HUVEC,then the effects of IGFBP4 on the aging process of these endothelial cells were studied by using light microscopy,senescence-associated( SA) β-galactosidase staining,and cell cycle analysis. Results After lentivirus transfection,the HUVEC passage number of the overexpressing IGFBP4( +) group( IGFBP( +) group) was higher than that of the empty vector group( control group) and IGFBP4 silenced groups( IGFBP4(-) group)( 14. 33 ± 0. 67 vs9. 67 ± 0. 33 and 10. 67 ± 0. 33,P < 0. 05); The cell senescence rate of the IGFBP4( +) group was lower than that of the control group and IGFBP4(-) group in every passage( take the 6th passage for example,24. 60% ± 0. 90% vs 34. 92%± 0. 92% and 33. 74% ± 0. 62%,P < 0. 05); Along with degenerate,the decreased cell proliferation index( △PI) from young passage( 2nd passage) to old passage( 6th passage) of IGFBP4( +) was smaller than control group and IGFBP4(-) group( 10. 35% ± 0. 57% vs 14. 90% ± 0. 85% and 13. 99% ± 0. 65%,P < 0. 05). Conclusions IGFBP4 overexpression could inhibit HUVEC senescence.