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Atherosclerosis (AS) is the primary etiology of cardiovascular disease, which is considered the leading cause of death all over the world. MicroRNA miR-499-5p was involved in the functional regulation of myocardial and skeletal muscle, whereas its role in atherosclerosis, especially in vascular smooth muscle cells (VSMCs), remains unclear. Our study aims to investigate the effects of miR-499-5p in the proliferation and migration of VSMCs and potential mechanisms. We used mouse aortic vascular smooth muscle cells (MOVAS) and ApoE -/- mice to establish the models of AS in vitro and in vivo, respectively. RT-PCR was performed to detect the expression level of miR-499-5p. Subsequently, Cell Counting Kit-8 (CCK-8) assays, Transwell assays, and wound-healing assays were used to evaluate cell proliferation and migration. Dual-luciferase reporter assay was performed to validate the interaction between miR-499-5p and SOX6. miR-499-5p significantly increased in aorta tissues of mice in AS tissues and vascular smooth muscle cells treated with ox-LDL. miR-499-5p overexpression could promote the proliferation and migration of MOVAS. Bioinformatics analysis predicted and further experiments verified that miR-499-5p could directly bind to the 3'-untranslated region (UTR) region of SOX6. Further, miR-499-5p induced an increased expression of smooth muscle proliferation and migration-related genes, PCNA, cyclin D1 , and matrix metalloproteinase ( MMP2 ), as well as the decreased expression of proliferation inhibiting factor p21 , which was significantly reversed by SOX6 overexpression. miR-499-5p boosts the proliferation and migration of smooth muscle cells by binding and inhibiting SOX6 expression. The miR-499-5p/SOX6 axis may present a promising therapeutic implication for the prevention and treatment of cardiovascular diseases.

Backgrounds: The thioredoxin-1 has atheroprotective effects via regulating oxidative stress and inflammation. In addition, the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome also contributes to atherosclerosis development. However, whether the thioredoxin-1 suppresses atherosclerosis development by modulating the NLRP3 inflammasome remains unclear., Methods: The regulation of NLRP3 inflammasome by thioredoxin-1 was determined in vitro on macrophage cells after ox-LDL (oxidized low-density lipoprotein) stimulation. The IL-1β and caspase-1 p10 secretion were assessed by ELISA and western blot. Finally, the thioredoxin-1/NLRP3 inflammasome pathway was confirmed in apolipoprotein E-deficient mice., Results: Thioredoxin-1 suppressed the expression of NLRP3, the secretion of IL-1β and caspase-1 p10 in vitro. And ROS stimulation activated the NLRP3 inflammasome which was inhibited by thioredoxin-1. In the mouse model of atherosclerosis, thioredoxin-1 delivered by lentivirus vector inhibited atherosclerosis development. And the atheroprotective effects of thioredoxin-1 were attenuated by ROS stimulation. Furthermore, the regulation of NLRP3 inflammasome by thioredoxin-1 was also confirmed in vivo., Conclusions: We demonstrated here that the thioredoxin-1 had atheroprotective functions through thioredoxin-1/NLRP3 inflammasome pathway.

Backgrounds: C1q tumor necrosis factor-related protein 9 (CTRP9) has been suggested to exert an atheroprotective effect by modulating the inflammation, foam cell formation, endothelia and smooth muscle cell function via Adenosine Monophosphate Activated Protein Kinase (AMPK) pathway. On the other hand, the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome plays an critical role in the atherosclerosis development, which is regulated by the AMPK. However, whether the CTRP9 affects the activity of NLRP3 inflammasome during the atherosclerosis development remains unclear, which would be elucidated in the current study., Methods: The macrophage cells were stimulated with the oxidized low-density lipoprotein (ox-LDL) and also treated with the recombinant CTRP9 in the meantime. The activation of NLRP3 inflammasome was determined by measuring the releasing of IL-1β and caspase-1 p10 via ELISA and western blot, respectively. Then the AMPK was inhibited in macrophages by Dorsomorphin. Finally, the CTRP9-AMPK-NLRP3 inflammasome pathway was validated in the mouse model of atherosclerosis., Results: The CTRP9 could down-regulate the expression of NLRP3 protein and also the activity of NLRP3 inflammasome in the ox-LDL activated macrophages. Inhibiting the AMPK significantly restored the activities of NLRP3 inflammasome. In the apolipoprotein E-deficient mice, lentiviral expression of CTRP9 could suppress the atherosclerosis development, which could be abolished by AMPK inhibition., Conclusion: Our data here indicated that the CTRP9 showed atheroprotective function via CTRP9-AMPK- NLRP3 inflammasome pathway., (Copyright © 2019. Published by Elsevier B.V.)