验证甲状旁腺激素(PTH)对骨内血管的生物学效应,这项研究旨在研究间歇性PTH给药后小鼠股骨内粘蛋白阳性血管和血管周围细胞的组织学改变。为了与骨骼中的血管进行比较,我们检查了肝脏内粘蛋白阳性血管和周围αSMA免疫反应性血管周围细胞的分布,肾,和有或没有PTH给药的主动脉。
六周大的雄性C57BL/6J小鼠接受hPTH[1-34]或媒介物两周。安乐死后,所有小鼠均用多聚甲醛溶液固定,和右股骨,肾,肝脏,提取主动脉进行内粘蛋白的免疫组织化学分析,αSMA,ephrinB2、EphB4和HIF1α。在左股骨上进行半薄切片的光学显微镜观察和超薄切片的透射电子显微镜(TEM)观察。
间歇性PTH给药后,αSMA反应性/ephrinB2阳性基质细胞出现在骨骼中的内粘蛋白阳性/EphB4免疫反应性血管周围。此外,PTH治疗后,在血管内皮细胞中观察到EphB4和HIF1α的强烈免疫反应性。在TEM观察下,PTH处理的血管周围的几个基质细胞表现出发育良好的粗面内质网。与骨组织相反,αSMA阳性基质细胞在肾脏内粘蛋白阳性血管周围没有增加,肝脏,或者主动脉,即使在PTH给药后。
这些发现表明,间歇性PTH给药增加骨组织中的αSMA反应性/ephrinB2阳性血管周围基质细胞,但不增加肾脏中的细胞。肝脏,或者主动脉,表明PTH优先影响骨骼中的血管。
To verify the biological effects of parathyroid hormone (PTH) on the blood vessels in the bone, this study aimed to investigate histological alterations in endomucin-positive blood vessels and perivascular cells in murine femora after intermittent PTH administration. For comparison with blood vessels in the bone, we examined the distribution of endomucin-positive blood vessels and surrounding
αSMA-immunoreactive perivascular cells in the liver, kidney, and aorta with or without PTH administration.
Six-week-old male C57BL/6J mice received hPTH [1-34] or vehicle for two weeks. All mice were fixed with a paraformaldehyde solution after euthanasia, and the right femora, kidney, liver, and aorta were extracted for immunohistochemical analysis of endomucin,
αSMA, ephrinB2, EphB4, and HIF1α. Light microscopic observations of semi-thin sections and transmission electron microscopic (TEM) observations of ultra-thin sections were performed on the left femora.
After intermittent PTH administration,
αSMA-reactive/ephrinB2-positive stromal cells appeared around endomucin-positive/EphB4-immunoreactive blood vessels in the bone. In addition, intense immunoreactivities of EphB4 and HIF1α were seen in vascular endothelial cells after the PTH treatment. Several stromal cells surrounding PTH-treated blood vessels exhibited well-developed rough endoplasmic reticulum under TEM observations. In contrast to bone tissues,
αSMA-positive stromal cells did not increase around the endomucin-positive blood vessels in the kidney, liver, or aorta, even after PTH administration.
These findings show that intermittent PTH administration increases
αSMA-reactive/ephrinB2-positive perivascular stromal cells in bone tissue but not in the kidney, liver, or aorta, suggesting that PTH preferentially affects blood vessels in the bone.