Department of Geriatrics, The First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou, 350005, Fujian, People's Republic of China.
Department of General Medicine, The First Affiliated Hospital of Fujian Medical University, Fuzhou, People's Republic of China.
BMC Pulm Med. 2022 Mar 28;22(1):111. doi: 10.1186/s12890-022-01905-3.
The zinc transporter ZIP12 is a membrane-spanning protein that transports zinc ions into the cytoplasm from the extracellular space. Recent studies demonstrated that upregulation of ZIP12 is involved in elevation of cytosolic free zinc and excessive proliferation of pulmonary arterial smooth muscle cells (PASMCs) induced by hypoxia. However, the expression of ZIP12 and its role in pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT) in rats have not been evaluated previously. The aim of this study was to investigate the effect of ZIP12 on the proliferation and migration of PASMCs and its underlying mechanisms in MCT-induced PAH.
A PAH rat model was generated by intraperitoneal injection of 20 mg/kg MCT twice at one-week intervals. PASMCs were isolated from the pulmonary arteries of rats with MCT-induced PAH or control rats. The expression of ZIP12 and related molecules was detected in the lung tissues and cells. A ZIP12 knockdown lentivirus and an overexpressing lentivirus were constructed and transfected into PASMCs derived from PAH and control rats, respectively. EdU assays, wound healing assays and Western blotting were carried out to explore the function of ZIP12 in PASMCs.
Increased ZIP12 expression was observed in PASMCs derived from MCT-induced PAH rats. The proliferation and migration of PASMCs from PAH rats were significantly increased compared with those from control rats. These results were corroborated by Western blot analysis of PCNA and cyclin D1. All these effects were significantly reversed by silencing ZIP12. Comparatively, ZIP12 overexpression resulted in the opposite effects as shown in PASMCs from control rats. Furthermore, selective inhibition of AKT phosphorylation by LY294002 abolished the effect of ZIP12 overexpression on enhancing cell proliferation and migration and partially suppressed the increase in ERK1/2 phosphorylation induced by ZIP12 overexpression. However, inhibition of ERK activity by U0126 resulted in partial reversal of this effect and did not influence an increase in AKT phosphorylation induced by ZIP12 overexpression.
ZIP12 is involved in MCT-induced pulmonary vascular remodeling and enhances the proliferation and migration of PASMCs. The mechanism of these effects was partially mediated by enhancing the AKT/ERK signaling pathways.
锌转运蛋白 ZIP12 是一种跨膜蛋白，可将锌离子从细胞外空间转运到细胞质中。最近的研究表明，ZIP12 的上调参与了缺氧诱导的细胞质游离锌的升高和肺动脉平滑肌细胞（PASMC）的过度增殖。然而，先前尚未评估过 ZIP12 在大鼠单硝酸异山梨酯（MCT）诱导的肺动脉高压（PAH）中的表达及其作用。本研究旨在探讨 ZIP12 对 MCT 诱导的 PAH 中 PASMC 增殖和迁移的影响及其潜在机制。
通过腹腔内注射 20mg/kg MCT 两次，间隔一周，建立 PAH 大鼠模型。从 MCT 诱导的 PAH 大鼠或对照大鼠的肺血管中分离 PASMC。检测肺组织和细胞中 ZIP12 及相关分子的表达。构建并转染 ZIP12 敲低慢病毒和过表达慢病毒分别进入来自 PAH 和对照大鼠的 PASMC。进行 EdU 测定、划痕愈合测定和 Western blot 分析以探索 ZIP12 在 PASMC 中的功能。
在来自 MCT 诱导的 PAH 大鼠的 PASMC 中观察到 ZIP12 表达增加。与对照大鼠相比，PAH 大鼠的 PASMC 增殖和迁移明显增加。这些结果通过 PCNA 和细胞周期蛋白 D1 的 Western blot 分析得到证实。所有这些作用均通过沉默 ZIP12 得到显著逆转。相比之下，ZIP12 的过表达导致对照大鼠 PASMC 中出现相反的效果。此外，LY294002 对 AKT 磷酸化的选择性抑制消除了 ZIP12 过表达对增强细胞增殖和迁移的作用，并部分抑制了 ZIP12 过表达引起的 ERK1/2 磷酸化的增加。然而，U0126 抑制 ERK 活性导致这种作用的部分逆转，并且不影响 ZIP12 过表达诱导的 AKT 磷酸化的增加。
ZIP12 参与 MCT 诱导的肺血管重塑，并增强 PASMC 的增殖和迁移。这些作用的机制部分是通过增强 AKT/ERK 信号通路来介导的。
