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INTRODUCTION: Exosome-miR-146a is significantly increased in patients with Atherosclerosis (AS), but its mechanism and effect on AS have not been fully elucidated. OBJECTIVES: To explore the change rule and mechanism of exosomes release, and the role and molecular mechanism of exosome-miR-146a in AS. METHODS: We isolated and identified exosomes from THP-1 macrophages after treating them with ox-LDL. Then used co-immunoprecipitation and silver staining to identify the proteins involved in regulating exosome release. PKH67 was used to label exosomes to confirm that cells can absorb them, and then co-culture with HVSMCs for cell proliferation and migration detection. The target genes of miR-146a were screened and identified through bioinformatics and luciferase activity assay, and the expression of miR-146a and related proteins was detected through qRT-PCR and Western blot in HUVECs. An AS model in LDLR-/- mice induced by a high-fat diet was developed to investigate the impact of exosome-miR-146a on AS. RESULTS: The results showed that experimental foam cells from AS showed higher expression of miR-146a. It was observed that NMMHC IIA and HSP70 interacted to regulate the release of exosomes. And HUVECs can absorb exosomes derived from macrophages. In addition, we also found that miR-146a directly targeted the SMAD4 gene to modulate the p38 MAPK signaling pathway, thereby mediating HUVECs damage. Furthermore, exosome-miR-146a induced abnormal proliferation and migration of HVSMCs. The expression of miR-146a was significantly reduced in miR-146a-mimics mice and increased in miR-146a inhibitor mice whereas the inhibition of miR-146a effectively reduced while increasing miR-146a worsened AS in mice. CONCLUSION: Our findings expressed the potential of miR-146a as a favorable therapeutic target for AS, however, further exploration is suggestive for deep understanding of the mechanisms regulating exosome-miR-146a release in vivo and to develop effective therapeutic strategies involving miR-146a.
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Premna microphylla Turcz. is a commonly used traditional Chinese medicine totreatdysentery and appendicitis. Present study is focused to explore antioxidants and other compounds in the Premna microphylla Turcz. stem. Assessment of chemical composition was done with high sensitivity UPLC-LTQ-Orbitrap-MS and for Separation Thermo Hypersil Gold (100 mm × 2.1 mm, 1.9 µm) was used while electrospray ionization (ESI) was used for the mass spectrometry. 18 compounds were identified including Vitexin (1), Schaftoside (2), Vicenin-2 (3), Apigenin-6, 8-di-C-arabinoside (4), Apigenin-7-O-ß-d-glucoside (5), Carnosic acid (6), Apigenin-8-C-ß-d-xylopyranoside (7), Prostratin (8), Aurantio-obtusin-ß-d-glucoside (9), Royleanone (10), 5-hydroxy-7,3',4'-Trimethoxy flavonols (11), 6-Hydroxy-5,6-dehydrosugiol (12), 14-deoxycoleon (13), Arucadiol (14), Obtusinone-B (15), Trehalose (16), Citric acid (17) and Betaine (18). Among these, 6 compounds including (6), (8), (9), (16), (17) and (18) were identified first time within this genus and plant. Study highlights the importance of Premna microphylla Turcz. stem extract for strong therapeutic potential against oxidation-related diseases.
