动物造模,肺动脉高压 z-bio 2022-09-24 276

　　Objective To inhibit endoplasmic reticulum stress in a rat model of pulmonary arterial hypertension induced by monocrotaline, and to observe the role of endoplasmic reticulum stress-mitochondrial pathway in pulmonary arterial hypertension in rats.

　　Methods Forty-five SD rats were selected and randomly divided into 3 groups: normal control group, monocrotaline-induced pulmonary arterial hypertension (PAH) group and 4-phenylbutyric acid (4-phenylbutyric acid, 4-phenylbutyric acid) group. 4-PBA) drug intervention group, 15 rats in each group. The biological information acquisition system was used to measure the average pulmonary artery pressure and average right ventricular pressure of the rats in each group. The changes of mitochondrial status in pulmonary vascular smooth muscle cells were observed under electron microscope; the mRNA expression levels of key factors of endoplasmic reticulum stress-mitochondrial autophagy pathway were determined by qPCR molecular biology method.

　　Results (1) The mean pulmonary artery pressure and mean right ventricular pressure in the monocrotaline-induced PAH group were increased. After 4-PBA intervention, the mean pulmonary artery pressure and mean right ventricular pressure were decreased compared with the PAH group (P<0.001). (2) After HE staining, it was found that the PAH group had obvious remodeling of pulmonary small blood vessels, and the measurement of vascular remodeling indexes showed that the thickness of the pulmonary small arteries was increased and the lumen was narrowed (P<0.05). (3) Electron microscope observation of the ultrastructure of pulmonary vascular smooth muscle cells showed that the mitochondria of pulmonary vascular smooth muscle cells in the PAH group were swollen, the structure of mitochondrial cristae was destroyed, dissolved and disappeared, and the phenomenon of mitophagy was increased. After inhibiting endoplasmic reticulum stress, the damage to the normal mitochondrial structure was reduced, and mitophagy was reduced. (4) The mRNA levels of key factors in the endoplasmic reticulum stress-mitochondrial autophagy pathway were determined, and it was found that the mRNA expression levels of endoplasmic reticulum stress-related factors PERK, ATF4, Bcl-2 and CHOP were up-regulated in the PAH group (P<0. 001), the expression level of Mfn2 (mitofusin-2), a key factor in mitochondrial fusion, was down-regulated, the expression of Drp1 (dynamin-related protein 1, Drp1), a key factor in mitochondrial fission, was up-regulated (P<0.001), and autophagy-related factor 12 (autophagy related 12) , Atg12), microtubule-associated proteins 1A and 1B-light chain 3 (microtubule-associated proteins 1A and 1B, LC3), p62 (sequestosome-1, p62/SQSTM1) mRNA expression was up-regulated (P<0.01). After inhibiting ER stress, the mRNA expression levels of ER stress-related factors decreased (P<0. 001), the mitochondrial fusion factor Mfn2 was up-regulated (P<0. 001), and the mRNA expression of mitochondrial fission factor Drp1 was down-regulated (P<0.001), the mRNA expression levels of Atg12, LC3 and p62 were decreased (P<0.01).

　　Conclusion Endoplasmic reticulum stress may play an important role in the occurrence and development of pulmonary arterial hypertension through the mitophagy pathway. Intervention of this pathway may provide new therapeutic ideas for the prevention and treatment of pulmonary arterial hypertension.