LINC00346 regulates NLRP1-mediated pyroptosis and autophagy via binding to microRNA-637 in vascular endothelium injury.

Endothelial injury and dysfunction contributes to atherosclerosis. LINC00346 plays a key role in vascular endothelial cell injury, however, the specific mechanism remains unclear. This study intends to further explore the relationship between LINC00346 and vascular endothelial injury. Circulating LINC00346 was significantly elevated in patients with coronary artery disease and had high diagnostic value for coronary artery disease. In cell experiments, we found that LINC00346 expression was significantly increased in the oxidized low-density lipoprotein (ox-LDL) intervention group, and LINC00346 knockdown delayed ox-LDL induced human umbilical vein endothelial cell (HUVEC) endothelial-to-mesenchymal transition. In addition, knockdown of LINC00346 mitigated ox-LDL-induced NOD-like receptor protein 1 (NLRP1)-mediated inflammasome formation and pyroptosis, but had no significant effect on NLRP3. By observing the number of autophagosome and detecting intracellular autophagic flux, we found that LINC00346 knockdown inhibited the ox-LDL-induced increase in intracellular autophagy level. Dual-luciferase reporter assay, RNA immunoprecipitation assay, and RNA-pull down assay were performed to confirm the inter-molecular interaction. LINC00346 acted as microRNA-637 sponge to up-regulate the expression of NLRP1. Up-regulation of microRNA-637 alleviated NLRP1-mediated pyroptosis in HUVEC and reduced intracellular autophagosome and autolysosome formation. Finally, we explored whether pyropotosis and autophagy interact with each other. We found that inhibition of intracellular autophagy could alleviate NLRP1-mediated pyroptosis. In conclusion, LINC00346 inhibited the activation of NLRP1-mediated pyroptosis and autophagy via binding to microRNA-637, therefore mitigating vascular endothelial injury.

MicroRNA-143-5p modulates pulmonary artery smooth muscle cells functions in hypoxic pulmonary hypertension through targeting HIF-1α.

This paper explores the potential mechanism of microRNA-143-5p regulation effects on pulmonary artery smooth muscle cells (PASMCs) functions in hypoxic pulmonary hypertension (HPH) via targeting HIF-1a, which may offer a new idea for HPH therapy. PASMCs were transfected with mimics control/miR-143-5p mimics or inhibitor control/miR-143-5p inhibitor. We used Western blotting and RT-qPCR to detect the protein and mRNA expressions, CCK-8 assay to detect cellular viability, Annexin V-FITC/PI staining and caspase- 3/cleaved caspase-3 protein to evaluate cellular apoptosis, transwell migration experiment for cellular migration measurement and Dual luciferase reporter gene assay to prove the target of miR-143-5p. Cells under hypoxic condition presented the decreased protein and mRNA expressions of α-smooth muscle actin (SM-α-actin), Myocardin, smooth muscle myosin heavy chain (SMMHC), and smooth muscle-22α (SM22α), Calponin1 and Hypoxia-inducible factor-1α(HIF-1α), the increased cell viability and miR-143-5p level; Overexpression of miR-143-5p obviously reduced vascular smooth muscle-specific contraction marker protein levels and cellular apoptosis, increased cellular migration of PASMCs with hypoxia stimulation; Low-expression of miR-143-5p caused the opposite changes, while co-transfected with Si HIF-1 α blocked the beneficial effects of miR-143-5p inhibition on PASMCs under hypoxia. MicroRNA-143-5p can promote the phenotype conversion, proliferation and migration of pulmonary artery smooth muscle cells under hypoxic condition through direct targeting of HIF-1α.

[Effects of irbesartan on Notch1 signaling pathway in diabetic rats with myocardial injury].

OBJECTIVE: To investigate the effects and mechanisms of irbesartan on myocardial injury in diabetic rats, and to analyze the changes of Notch1 signaling pathway in it. METHODS: Thirty rats were randomly divided into four groups:normal control group (CON, n=6), high calorie group (HC, n=6) and diabetes mellitus group (DM, n=9), irbesartan + diabetes group (Ir + DM, n=9). After modeling 8 weeks later, the body weight ratio and left ventricular weight index were measured and the serum levels of triglyceride (TG) and total cholesterol (TC) were measured by automatic biochemical analyzer. The changes of superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in myocardium of rats were determined by the kit and the expressions of B-cell lymphoma-2 (Bcl-2) and Bcl-2 assaciated X protein (Bax) protein in myocardium were detected by immunohistochemistry. The expressions of Notch1, Hes-1 and jagged-1 in myocardium of rats were detected by Western blot. RESULTS: Compared with CON group, the levels of heart weight/body weight (H/B), left ventricular weight index(LVWI) and fasting blood glucose(FBG) in HC group were not significantly changed, while the levels of blood lipids, MDA and Bax were increased significantly, and the expressions of SOD, Bcl-2 and Notch1, Hes-1 and Jagged-1 were decreased. Compared with HC group, the levels of H/B, LVWI, FBG, MDA and Bax in DM group were increased significantly, and the levels of SOD, Bcl-2 and Notch1, Hes-1 and Jagged-1 were decreased. The expression of H/B, LVWI, Notch1, Hes-1 and Jagged-1 in Ir+DM group were increased, but there was no significant difference between the other indexes. The H/B and LVWI in Ir + DM group were significantly lower than those in DM group, the levels of blood lipid and blood glucose did not change significantly, but the incidence of oxidative stress and apoptosis was reduced. While Notch1, Hes-1, Jagged -1 protein expressions were increased. CONCLUSIONS: Diabetes can induce myocardial injury, and irbesartan has myocardial protective effects through activation of Notch1.