PVT1促进PAH大鼠肺动脉平滑肌细胞增殖和迁移的作用机制研究

摘要 目的：研究浆细胞瘤多样异位基因1（PVT1）在肺动脉高压（PAH）大鼠中对于肺动脉平滑肌细胞(PASMCs)增殖和迁移的作用及其可能的机制。方法：将16只成年雄性SD大鼠随机分为肺动脉高压组（PAH组）和对照组，每组8只大鼠。PAH组大鼠通过单次项背部皮下注射MCT溶液造模，对照组大鼠给予单次项背部皮下注射等量生理盐水。通过胸右心室穿刺法测量右心室压力。取各组大鼠肺组织，并进行原代肺动脉平滑肌细胞分离培养。通过RT-qPCR和Western blot检测PVT1及Fxr1在PAH组织及PASMCs中的表达水平；通过HE染色评估PAH组织的血管壁形态；免疫荧光法检测HPASMC的纯度；CCK-8法和伤口愈合迁移实验检测PASMCs增殖和迁移情况。结果：与对照组相比，PAH组大鼠肺组织血管壁厚度偏厚、肺动脉压显著升高（P<0.05）。PVT1在PAH组大鼠的PAH组织和PASMCs中的表达水平显著上调（P<0.05），且其表达与肺动脉压呈正相关。与对照组相比，转染sh-PVT1的PASMCs显示出较低的细胞活力，同时转染sh-PVT1有效敲低了PASMCs中PVT1的表达水平（P<0.01）。与对照组相比，PVT1的敲低抑制了PASMCs迁移能力（P<0.01）。在转染pcDNA-PVT1的PASMCs中发现较高的增殖能力，PVT1的过表达促进了PASMCs迁移能力（P<0.01）。与对照组相比，Fxr1在PAH模型组的PAH组织和PASMCs中的表达水平显著上调（P<0.01）。结论：PVT1通过调节Fxr1的表达促进PASMCs的增殖和迁移，PVT1可能是PAH诊断和预测指标。

The Mechanism of PVT1 on the Proliferation and Migration of Pulmonary Artery Smooth Muscle Cells in PAH Rats

ABSTRACT Objective: To study the effect of plasma cytoma multiple ectopic gene 1 (PVT1) on the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) in pulmonary hypertension (PAH) rats and its possible mechanism. Methods: Randomly divide 16 adult male SD rats into pulmonary hypertension group (PAH group) and control group, 8 rats in each group. Rats in the PAH group were modeled by a single subcutaneous injection of MCT solution (50 mg/kg) in the back, and rats in the control group were injected with an equal amount of normal saline. The right ventricular pressure was measured by thoracic right ventricular puncture. The lung tissue of each group of rats was taken, and the primary pulmonary artery smooth muscle cells were isolated and cultured. The expression levels of PVT1 and Fxr1 in PAH tissues and PASMCs were detected by RT-qPCR and Western blot. The vascular wall morphology of PAH tissue was evaluated by HE staining. The purity of PASMC was detected by immunofluorescence. CCK-8 method and wound healing migration test were used to detect the proliferation and migration of PASMCs. Results: Compared with the control group, the PAH group had a thicker lung tissue wall thickness and significantly increased pulmonary artery pressure (P<0.05). The expression level of PVT1 in PAH tissues and PASMCs of PAH group was significantly increased (P<0.05), and its expression was positively correlated with pulmonary artery pressure. Compared with the control group, PASMCs transfected with sh-PVT1 showed lower cell viability, while transfection with sh-PVT1 effectively knocked down the expression level of PVT1 in PASMCs (P<0.01). Compared with the control group, the knockdown of PVT1 inhibited the migration ability of PASMCs (P<0.01). High proliferation ability was found in PASMCs transfected with pcDNA-PVT1, and overexpression of PVT1 promoted migration ability of PASMCs (P<0.01). Compared with the control group, the expression levels of Fxr1 in the PAH tissue group and PASMCs of the PAH model group were significantly increased (P<0.01). Conclusion: PVT1 promotes the proliferation and migration of PASMCs by regulating the expression of Fxr1. PVT1 may be a diagnostic and predictive indicator of PAH.