Laboratory of Molecular Cell Biology of Faculty of Medicine and IBMC of Universidade do Porto, 4200-319 Porto, Portugal.
Microsc Microanal. 2010 Dec;16(6):699-709. doi: 10.1017/S1431927610094006. Epub 2010 Oct 25.
Aging is the single most significant risk factor for erectile dysfunction (ED), leading to structural modification of cavernous tissue and altering expression of vascular growth factors. The angiopoietin/Tie2 system has been recently considered as a potential target for therapy of vascular disorders, including ED. Hence, the aim of this study was to analyze expression of angiopoietin1 (Ang1), angiopoietin2 (Ang2), and their receptor Tie2 in corpus cavernosum (CC) of rat during aging (6, 12, 18, and 24 months). The expression of Ang1, Ang2, and Tie2 was studied by immunohistochemistry and immunofluorescence, followed by semiquantification after Western blotting. Both Ang1 and Ang2 were localized mainly in perivascular smooth muscle and endothelial cells, while Tie2 was strictly detected at the vascular endothelium. A significant decrease in Ang2's expression was observed at 12 months when compared with 6-month-old rats, a tendency that reverses in older animals. No significant differences were demonstrated for Ang1 or Tie2, which is consistent with their constitutive expression in CC. The ratios Ang1/Tie2 and Ang2/Tie2 were also calculated and both decrease during aging, while no marked variation was observed for Ang1/Ang2. Our results suggest that the angiopoietin/Tie2 system participate in the vascular maintenance and remodeling of the CC during aging.
衰老（aging）是导致勃起功能障碍（erectile dysfunction，ED）的最重要单一风险因素，会导致海绵体组织的结构改变，并改变血管生长因子的表达。血管生成素（angiopoietin）/Tie2 系统最近被认为是治疗血管疾病（包括 ED）的潜在靶点。因此，本研究旨在分析 Ang1（angiopoietin1）、Ang2（angiopoietin2）及其受体 Tie2 在衰老大鼠（6、12、18 和 24 个月）海绵体（corpus cavernosum，CC）中的表达。采用免疫组化和免疫荧光法研究 Ang1、Ang2 和 Tie2 的表达，然后通过 Western blot 进行半定量分析。Ang1 和 Ang2 主要定位于血管周围平滑肌和内皮细胞，而 Tie2 则严格定位于血管内皮细胞。与 6 个月龄大鼠相比，12 个月龄时 Ang2 的表达显著下降，这种趋势在老年动物中逆转。Ang1 或 Tie2 没有显示出显著差异，这与其在 CC 中的组成型表达一致。还计算了 Ang1/Tie2 和 Ang2/Tie2 的比值，两者在衰老过程中均下降，而 Ang1/Ang2 则没有明显变化。我们的研究结果表明，血管生成素/Tie2 系统参与了衰老过程中 CC 的血管维持和重塑。
