Department of Nephrology, The First Hospital of China Medical University, Shenyang, China.
Department of Nephrology, The First Hospital of China Medical University, Shenyang, China,
Blood Purif. 2019;47 Suppl 1(Suppl 1):17-23. doi: 10.1159/000496219. Epub 2019 Jan 30.
Abnormal mineral metabolism in patients with chronic kidney disease (CKD) may lead to vascular calcification, which is markedly associated with adverse events, including ischemic cardiac diseases and all-cause cardiovascular mortality. Thus, preventing and treating vascular calcification play an important role in improving the prognosis of CKD patients.
To investigate the potential functions of sclerostin and low-density lipoprotein receptor-related protein 4 (Lrp4) in alleviating the β-glycerophosphate (β-GP)-induced vascular smooth muscle cell (VSMC) calcification, and the protective effect of Ginkgo biloba extract (GBE).
VSMC were extracted from Sprague-Dawley rat aorta and cultured in medium. The VSMCs were divided into 3 groups: (1) Negative control group, (2) β-GP group, in which the VSMCs were treated with β-GP, and (3) GBE and β-GP group, where the VSMCs were treated with both β-GP and GBE. The calcium nodules within the cells were examined by using Alizarin red S staining. The mRNA expression levels of β-catenin and bone gamma-carboxyglutamic-acid-containing proteins (BGP) were detected by real-time PCR. The protein levels of sclerostin and Lrp4 were determined by Western blot.
Alizarin red S staining showed that the VSMCs in β-GP group had a distinct orange-red precipitate when compared with VSMCs in the negative control group, while the orange-red precipitate of the GBE and β-GP group was significantly reduced compared to the β-GP group. Real-time PCR showed that the mRNA levels of β-catenin and BGP in VSMCs of β-GP group were significantly higher than those of the negative control group (p < 0.05); while they were significantly reduced in VSMCs of the GBE and β-GP group (p < 0.05). Western blot results showed that the expression of sclerostin in the β-GP group was significantly higher than that in the control group (p < 0.05), whereas Lrp4 was significantly lower than in control group (p < 0.05). Sclerostin in GBE and β-GP group was significantly reduced (p < 0.05), but Lrp4 was significantly elevated when compared with that of the β-GP group (p < 0.05).
β-GP induced VSMC calcification by activating the Wnt/β-catenin signaling pathway. Sclerostin and Lrp4 were involved in β-GP-induced VSMC calcification and play an important role. GBE could alleviate VSMC calcification induced by β-GP through inhibiting the Wnt/β-catenin signaling pathway.
慢性肾脏病（CKD）患者的异常矿物质代谢可能导致血管钙化，这与包括缺血性心脏病和全因心血管死亡率在内的不良事件显著相关。因此，预防和治疗血管钙化对于改善 CKD 患者的预后具有重要意义。
研究骨硬化蛋白（sclerostin）和低密度脂蛋白受体相关蛋白 4（Lrp4）在缓解β-甘油磷酸（β-GP）诱导的血管平滑肌细胞（VSMC）钙化中的潜在作用，以及银杏叶提取物（GBE）的保护作用。
从 Sprague-Dawley 大鼠主动脉中提取 VSMC 并在培养基中培养。将 VSMC 分为 3 组：（1）阴性对照组，（2）β-GP 组，其中 VSMC 用β-GP 处理，（3）GBE 和β-GP 组，其中 VSMC 用β-GP 和 GBE 处理。通过茜素红 S 染色检查细胞内的钙结节。通过实时 PCR 检测β-catenin 和骨γ-羧基谷氨酸蛋白（BGP）的 mRNA 表达水平。通过 Western blot 测定骨硬化蛋白和 Lrp4 的蛋白水平。
茜素红 S 染色显示，与阴性对照组相比，β-GP 组的 VSMC 有明显的橙红色沉淀物，而 GBE 和β-GP 组的橙红色沉淀物明显少于β-GP 组。实时 PCR 显示，β-GP 组 VSMC 的β-catenin 和 BGP mRNA 水平明显高于阴性对照组（p<0.05）；而 GBE 和β-GP 组 VSMC 的β-catenin 和 BGP mRNA 水平明显低于阴性对照组（p<0.05）。Western blot 结果显示，β-GP 组骨硬化蛋白的表达明显高于对照组（p<0.05），而 Lrp4 明显低于对照组（p<0.05）。GBE 和β-GP 组的骨硬化蛋白明显减少（p<0.05），但 Lrp4 明显高于β-GP 组（p<0.05）。
β-GP 通过激活 Wnt/β-catenin 信号通路诱导 VSMC 钙化。骨硬化蛋白和 Lrp4 参与了β-GP 诱导的 VSMC 钙化，发挥了重要作用。GBE 可通过抑制 Wnt/β-catenin 信号通路减轻β-GP 诱导的 VSMC 钙化。
