Cardiac fibroblast miR-27a may function as an endogenous anti-fibrotic by negatively regulating Early Growth Response Protein 3 (EGR3).

Pathological myocardial fibrosis and hypertrophy occur due to chronic cardiac stress. The microRNA-27a (miR-27a) regulates collagen production across diverse cell types and organs to inhibit fibrosis and could constitute an important therapeutic avenue. However, its impact on hypertrophy and cardiac remodelling is less well-known. We employed a transverse aortic constriction (TAC) murine model of left ventricular pressure overload to investigate the in vivo effects of genetic miR-27a knockout, antisense inhibition of miR-27a-5p and fibroblast-specific miR-27a knockdown or overexpression. In silico Venn analysis and reporter assays were used to identify miR-27a-5p's targeting of Early Growth Response Protein 3 (Egr3). We evaluated the effects of miR-27a-5p and Egr3 upon transforming growth factor-beta (Tgf-ß) signalling and secretome of cardiac fibroblasts in vitro. miR-27a-5p attenuated TAC-induced cardiac fibrosis and myofibroblast activation in vivo, without a discernible effect on cardiac myocytes. Molecularly, miR-27a-5p inhibited transforming growth factor-beta (Tgf-ß) signalling and pro-fibrotic protein secretion in cardiac fibroblasts in vitro through suppressing the pro-fibrotic transcription factor Early Growth Response Protein 3 (Egr3). This body of work suggests that cardiac fibroblast miR-27a may function as an endogenous anti-fibrotic by negatively regulating Egr3 expression.

AntagomiR-29b inhibits vascular and valvular calcification and improves heart function in rats.

We aimed to investigate the role of the miR-29b and its effect on TGF-ß3 pathway in vascular and valvular calcification in a rat model of calcific aortic valve diseases (CAVD). A rat model of CAVD was established by administration of warfarin plus vitamin K. The expression levels of miR-29b, osteogenic markers and other genes were determined by qRT-PCR, Western blot and/or immunofluorescence and immunohistochemistry. The calcium content and alkaline phosphatase (ALP) activity were measured. The calcium content, ALP activity and osteogenic markers levels in calcified aorta and aortic valve were augmented compared to controls. The expression of miR-29b, p-Smad3, and Wnt3 and ß-catenin was significantly up-regulated, whereas TGF-ß3 was markedly down-regulated. However, compared with the CAVD model group, the calcium content and ALP activity in rats treated with antagomiR-29b were significantly decreased, and antagomiR-29b administration reversed the effects of CAVD model on the expression of miR-29b and osteogenic markers. Inhibition of miR-29b in CAVD rats prevented from vascular and valvular calcification and induced TGF-ß3 expression, suggesting that the miR-29b/TGF-ß3 axis may play a regulatory role in the pathogenesis of vascular and valvular calcification and could play a significant role in the treatment of CAVD and other cardiovascular diseases.

MicroRNA-29b regulates pyroptosis involving calcific aortic valve disease through the STAT3/SOCS1 pathway.

BACKGROUND: CAVD (calcific aortic valve disease) involves an inflammatory response similar to pyroptosis; therefore, we speculated that the progression of pyroptosis might be involved in the pathogenesis of CAVD. METHODS: We first investigated the expression of pyroptosis related genes in human CAVD, non-CAVD control and AS (calcific aortic stenosis) tissues. We further confirmed these genes by using CAVD cell and mouse models. Finally, we explored the functional molecular mechanism in the cell model. RESULTS: Our recent studies found that miR-29b plays an important role in CAVD, and we wanted to further address whether miR-29b is a key factor in the progression of pyroptosis related to CAVD. In this study, we found NLRP3 was highly expressed in CAVD patients and models. In contrast, SOCS1, a suppressor of NLRP3, showed reduced expression in CAVD. Furthermore, we found that ASC, Caspase-1, IL-1ß, Cleaved IL-18 and p-JAK2 were all upregulated in the tissues of CAVD patients, suggesting the likelihood of activation of the inflammasome. Then, we found that miR-29b participated in the NLRP3-regulated CAVD pathway through its target gene STAT3 (signal transducer and activator of transcription 3). Finally, we found that a miR-29b inhibitor could mitigate the increases in osteogenic differentiation and pyroptosis and that SOCS1 showed negative regulation of osteogenic differentiation and pyroptosis in CAVD. CONCLUSION: These findings suggested NLRP3 inflammasome-related genes are highly expressed in CAVD, and miR-29b reverses osteoblastic differentiation of aortic valve interstitial cells by regulating pyroptosis and inhibiting inflammation via the STAT3/SOCS1 pathway.

[Changes of monocyte and monocyte-platelet aggregates in different subgroups of thrombotic events in patients with acute myocardial infarction during PCI].

Objective To investigate the impact of thrombotic events on the alterations of monocyte and monocyte-platelet aggregates (MPAs) in patients with acute myocardial infarction (AMI) during percutaneous coronary intervention (PCI). Methods Blood was collected before PCI for flow cytometry. Monocyte subsets and MPAs were detected by four-color platform (CDl4-APC, CDl6-PE-Cy7, CD86-PE and CD41-Alexa FluorR488). According to the expression of the platelet surface marker CD41, the number of monocyte subsets and MPAs was analyzed using the fluorescent microspheres of absolute counting tube. The Wilcoxon rank sum test and receiver operating characteristic (ROC) curve analysis were performed. Results CD14+CD16++ monocytes in intraprocedural thrombotic events (IPTE) group were significantly fewer than those in non-IPTE group, and the percentage in total mononuclear cells decreased. Compared with non-IPTE group, MPA binding ratio and monocyte subset MPA binding ratio were significantly higher in IPTE group. ROC analysis showed that MPA binding ratio and subgroup MPA binding ratio had a better predictive value for IPTE in patients with AMI. Conclusion The CD14+CD16++ monocytes in IPTE group were significantly fewer than those in the non-IPTE group. MPA binding ratio and MPA binding ratio of monocyte subsets were significantly higher in the IPTE group than in the non-IPTE group, so they have a good predictive value for IPTE in patients with AMI.