缺氧诱导HIF-1α表达与兔血管平滑肌细胞增殖的关系

Relationship Between Hypoxia-Induced HIF-1 Alpha Expression and the Proliferation of Rabbit Aortic Smooth Muscle Cells

目的:探讨动静脉血管吻合口处再狭窄的机制,明确缺氧诱导血管平滑肌的缺氧诱导因子-1α(HIF-1α)表达与细胞增殖的关系。方法:52只新西兰大白兔行髂动静脉吻合术,随机分入术后常氧组(21%氧)、术后给氧组(30%氧)和假手术组。ELISA法检测兔血浆血小板源性生长因子B(PDGF-B)表达,Western blotting检测吻合口组织HIF-1α、PDGF-B、ERK1/2、Akt表达。以不同处理组的兔血浆培养兔主动脉平滑肌细胞,BrdU增殖试验检测细胞增殖,Western blotting检测细胞中HIF-1α、PDGF-B、ERK1/2、Akt表达。结果:术后常氧组兔血浆中PDGF-B和吻合口组织HIF1-α、PDGF-B、ERK1/2的表达明显增高。术后常氧组兔血浆培养的平滑肌细胞增生显著,其增生效应可被PDGF受体诺氨酸激酶阻滞剂AG1259阻断,缺氧条件下细胞内HIF1-α、PDGF-B、ERK1/2表达均明显增高。结论:局部缺氧是导致动静脉吻合口组织平滑肌细胞增殖、血管再狭窄发生的重要因素,术后氧疗是降低再狭窄发生的重要方法。

To investigate the relationship between the hypoxia-induced expression of hypoxia inducible factor （HIF）-la and the proliferation of rabbit aortic smooth muscle cells. Methods： Fifty-two New Zealand rabbits received an arteriovenostomy in the common iliac artery and vein in a side-to-side manner and then randomly distributed to three different groups： normalair group （21% oxygen）, hyperoxia group（30% oxygen） and sham group. ELISA was used to measure the expression of PDGF in the plasma. Western blot was adopted to test the expression of HIF-la, PDGF, ERK1/2 and Akt in the wound tissue. The plasma samples were collected from different groups to culture rabbit aortic smooth muscle cells. BrdU test was used to measure the prolifera- tion of SMCs. Western blot was used to determine the expression of HIF-1a, ERK1/2 and ex-pression in SMCs. Results： PDGF was at a higher level in plasma in the hypoxia group as com- pared with other two groups（P^0.05）. The expression of HIF-I~, PDGF, ERK1/2, and Akt in the wound tissue was remarkably higher than those from hyperoxia group and sham group（P〈 0.05）. Rabbit aortic smooth muscle ceils cultivated by the plasma from the hypoxia group showed a more significant proliferation （P〈 0. 05） while this proliferation was blocked when PDGF R antagonist AG1259 was added to the medium. The expressions of HIF-la, PDGF and Akt in the aortic smooth muscle cells were higher than those in hyperoxia group and sham group. Conclusion： Hypoxia in the lumen may play a role in the proliferation of smooth muscle cells in the arteriovenous anastomosis tissue and the restenosis of the graft vein. The short-term adminis- tration of supplemental oxygen could be an inexpensive, safe, simple, and effective way to con- trol intimal hyperplasia.