促生长激素释放激素激动剂JI-34对小鼠血管新生的影响及可能机制

摘要

Objective To explore the effect and the possible mechanism of growth hormone releasing hormone agonist JI - 34 on angiogen-esis of bone marrow derived mesenchymal stem cells(BM - MSCs). Methods A total of 12 C57BL/ 6 mice were randomly divided into(JI - 34+ MIA - 602)group,JI - 34 group and control group. BM - MSCs of mice in JI - 34 group were pretreated in 10 - 8 mol/ L JI - 34 for 24 h,BM- MSCs of mice in(JI - 34&MIA - 602)group were pretreated in 10 - 8 mol/ L JI - 34 and 10 - 7 mol/ L growth hormone releasing hormone antago-nist MIA - 602 for 24 h,and BM - MSCs of mice in control group did not take any processing. Results Pipe cavity structure of BM - MSCs cells in JI - 34 group was obviously increased,the length of tube cavity of new blood vessels in mice was increased by 2. 17 times than that of mice in control group,and the difference was statistically significant( P ﹤ 0. 05). The difference in expression of GHRH - R among these three groups was not statistically significant( P ﹥ 0. 05). In comparison with the control group,the expression levels of VEGF - A and MMP - 9 protein of BM- MSCs in JI - 34 group were significantly increased,and the difference was statistically significant( P ﹤ 0. 05). The difference in levels of ex-pression of VEGF - A and MMP - 9 protein in BM - MSCs of(JI - 34&MIA - 602)group was not statistically significant( P ﹥ 0. 05). The levels of expression of STAT3 and pSTAT3 protein of BM - MSC in JI - 34 group were significantly higher than those of control group,and the difference was statistically significant( P ﹤ 0. 05). In comparison to control group,the difference in expression levels of STAT3 and pSTAT3 protein of BM- MSCs of(JI - 34&MIA - 602)group was not significant( P ﹤ 0. 05). Conclusion Through binding to the GHRH - R on BM - MSCs,JI -34 may activate the STAT3 signal pathway,and improve the expression of VEG - A and MMP - 9 in order to promote the angiogenesis.%目的：探讨促生长激素释放激素激动剂 JI -34对骨髓间质干细胞（BM - MSCs）血管新生作用及影响，并研究可能相关机制。方法将12只6周龄的 C57BL/6小鼠随机分为对照组、JI -34组和（JI -34+ MIA -602）组，每组4只。实验组小鼠 BM - MSCs 处于10-8 mol/ L 促生长激素释放激素激动剂 JI -34下预处理24 h，（JI -34+ MIA -602）组小鼠 BM - MSCs 细胞同时加入10-8 mol/ L JI -34和10-7 mol/ L 促生长激素释放激素拮抗剂 MIA -602预处理24 h。对照组 BM - MSCs 不作任何处理。观察三组研究对象 BM - MSC 在 Matrigel 中管腔样结构新生数量及管腔长度的差异；采用 Western bolt 实验法检测三组小鼠 BM - MSCs 表面促生长激素释放激素受体（GHRH - R）、血管内皮生长因子- A （VEGF - A）、基质金属蛋白酶（MMP -9）、信号传导子及转录激活子-3（STAT3）蛋白的表达情况。结果 JI -34组BM - MSCs 细胞在 Matrigel 中管腔样结构数量和管腔长度增加，促进 BM - MSCs 细胞血管结构新生能力最明显，新生血管样管腔长度是对照组的2.17倍，差异具有统计学意义（ P ﹤0.05）；三组研究对象 BM - MSCs 细胞表面 GHRH - R 表达无显著性变化，差异无统计学意义（ P ﹥0.05）；与对照组相比，JI -34组 BM - MSCs 细胞 VEGF - A、MMP -9蛋白表达量明显升高，差异具有统计学意义（ P ﹤0.05）；（JI -34+ MIA -602）组 BM - MSCs 细胞 VEGF - A、MMP -9蛋白表达量与对照组相比，差异无统计学意义（ P ﹥0.05）；JI -34组 BM - MSCs 细胞 STAT3、pSTAT3蛋白表达水平显著高于对照组，差异具有统计学意义（ P ﹤0.05）。（JI -34+ MIA -602）组 BM - MSCs 细胞 STAT3、pSTAT3蛋白表达水平与对照组相比，差异不具有统计学意义（ P ﹥0.05）。结论 JI -34可能通过与 BM - MSCs 表面 GHRH - R 结合后通过激活STAT3信号通路，提高 VEGF - A 及 MMP -9的表达，促进 BM - MSCs 血管新生。