17-AAG对大鼠颈总动脉球囊损伤后内膜增生的影响及其作用机制

目的:研究17-丙烯胺-17去甲氧格尔德霉素(17-Allylamino-17-emethoxy-geldanamycin, 17-AAG)对球囊损伤后大鼠颈总动脉内膜增生的影响及可能作用机制。方法:将清洁级雄性SD大鼠36只按照随机数字法分为假手术组(Sham组)12只、球囊损伤组(Balloon injury, BI组)12只及17-AAG治疗组(17-AAG组)12只。采用2F Fogarty球囊建立大鼠颈总动脉球囊损伤组模型,17-AAG治疗组大鼠在建模后腹腔注射17-AGG(20 mg/kg 2d)。各组大鼠于球囊损伤3周后取损伤段颈总动脉,通过HE染色观察血管内膜形态学改变并评估内膜增生情况,免疫组化染色(Immunohistochemical staining,IHS)法检测血管壁增殖细胞核抗原(Proliferating cell nuclear antigen,PCNA)的表达,评估血管平滑肌细胞的增殖情况。流式细胞术检测血管平滑肌细胞的凋亡情况。结果:BI组、17-AAG组大鼠球囊损伤后颈总动脉内膜出现不同程度增生,内膜/中膜面积比(Intima area/Membrane area,I/M)均较Sham组显著升高(P0.05);17-AAG组的I/M较BI组明显下降(P0.05)。BI组、17-AAG组颈总动脉PCNA表达水平较Sham组明显升高(P0.05),较BI组显著降低(P0.05)。BI组、17-AAG组大鼠血管平滑肌细胞凋亡率较Sham组显著升高(P0.05);17-AAG组大鼠血管平滑肌细胞凋亡程度较BI组明显升高(P0.05)。结论:17-AAG对球囊损伤后颈总动脉内膜增生存在抑制作用,其机制可能是通过提高血管平滑肌细胞凋亡率影响其增殖程度。

A Study on the Influence of 17-Allylamino-17-emethoxy-geldanamycin on the Intimal Hyperplasia after Carotid Artery Balloon Injury in Rats

ABSTRACT Objective: To investigate the influence and possible mechanism of 17-Allylamino-17-emethoxy-geldanamycin(17-AAG) on the intimal hyperplasia after carotid artery balloon injury in rats. Methods: Thirty-six male SD rats were divided into Sham group (n=12), BI group (n=12) and 17-AAG group (n=12) randomly. SD rats were injured using a 2F Fogarty balloon embolectomy catheter. 17-AAG group were disposed by intraperitoneal injecting 17-AAG at a dose of 20 mg/kg2d. After carotid artery balloon injuried 21 days, the damage area of the segment were harvested, HE staining was performed to observe the morphological changes of intima and to evaluate the degree of intimal hyperplasia. The expression of proliferating cell nuclear antigen (PCNA) in each group were by immunohistochemical staining to evaluate the proliferation of vascular smooth muscle cells. The degree of apoptosis of vascular smooth muscle cells in each group were detected by flow cytometry. Results: The results of HE staining showed that there were different degrees of intimal hyperplasia following carotid artery injury in BI group and 17-AAG group. I/M ratio of BI group and 17-AAG group significantly increased than that of Sham group (P<0.05). I/M ratio of 17-AAG group distinctly decreased than that of BI group (P<0.05). The results of immunohistochemical staining showed that the expression of PCNA in carotid artery in BI group and 17-AAG group were significantly higher than that in Sham group (P<0.05). The expression of PCNA in 17-AAG group was significantly lower than that in BI group (P<0.05). Compared with Sham group, the apoptosis rate of vascular smooth muscle cells in BI and 17-AAG group significantly increased(P<0.05). Compared with BI group, the apoptosis rate of vascular smooth muscle cells in 17-AAG group obviously increased(P<0.05). Conclusion: The results of the present study demonstrated that 17-AAG appeared to attenuate intimal hyperplasia after carotid artery balloon injury in rats. The possible mechanism of inhibition of neointimal formation may be enhance the apoptosis rate of vascular smooth muscle cells.