Department of Pathology, Division of Experimental Pathology, Tokyo Women's Medical University, Tokyo, Japan.
Department of Pathology, Division of Experimental Pathology, Tokyo Women's Medical University, Tokyo, Japan.
Atherosclerosis. 2021 Feb;319:10-20. doi: 10.1016/j.atherosclerosis.2020.12.015. Epub 2020 Dec 21.
The mechanism of vascular calcification (VC) resembles that of bone metabolism, and a correlation has frequently been reported between calcification and vascular extracellular matrix (ECM) regulating its integrity; however, the detailed mechanisms remain unclear. In this study, we examined how the vascular ECM, especially collagen metabolism, is involved in the process of VC.
VC was modeled using 5-week-old male Sprague-Dawley rats fed a diet containing warfarin and vitamin K1 (WVK). Additionally, β-aminopropionitrile (BAPN) was administered to inhibit lysyl oxidase (LOX), which is an enzyme that mediates collagen cross-linking. Harvested aortic samples were analyzed by staining with alizarin red (AR), immunohistochemistry (IHC), transmission electron microscopy (TEM), and ex vivo microcomputed tomography (μCT).
Rats fed WVK developed increasing numbers of aortic medial calcifications (AMCs) over time. TEM images indicated punctate calcification within collagen fibers in the early phase of AMC. AR staining of translucent samples revealed the distribution and severity of calcification, and these lesions were significantly decreased in the BAPN group. Three-dimensional reconstructed μCT images that allowed the quantification of calcified volumes revealed that BAPN significantly reduced the bulk of calcification. Moreover, IHC showed that both LOX and collagen I were present around the sites of AMC, and thus the IHC-positive area was reduced in the BAPN group compared to the WVK group.
The results indicated that inhibition of LOX by BAPN attenuated AMC, and that collagen metabolism plays a significant role in the early pathogenesis of VC.
血管钙化（VC）的机制类似于骨代谢，钙化与血管细胞外基质（ECM）之间的相关性经常被报道，后者调节着血管的完整性；然而，其详细机制尚不清楚。在本研究中，我们研究了血管 ECM，特别是胶原代谢，如何参与 VC 过程。
使用喂食华法令和维生素 K1（WVK）饮食的 5 周龄雄性 Sprague-Dawley 大鼠来构建 VC 模型。此外，还给予β-氨基丙腈（BAPN）以抑制赖氨酰氧化酶（LOX），LOX 是一种介导胶原交联的酶。通过茜素红（AR）染色、免疫组织化学（IHC）、透射电子显微镜（TEM）和离体微计算机断层扫描（μCT）对采集的主动脉样本进行分析。
喂食 WVK 的大鼠随时间推移逐渐形成越来越多的主动脉中层钙化（AMC）。TEM 图像表明 AMC 早期阶段胶原纤维内存在点状钙化。半透明样本的 AR 染色显示了钙化的分布和严重程度，BAPN 组的这些病变明显减少。允许定量钙化体积的三维重建 μCT 图像表明 BAPN 显著减少了钙化总量。此外，IHC 显示 LOX 和胶原 I 均存在于 AMC 部位周围，因此与 WVK 组相比，BAPN 组的 IHC 阳性面积减少。
结果表明，BAPN 抑制 LOX 可减轻 AMC，胶原代谢在 VC 的早期发病机制中起着重要作用。
