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MiR-761 promotes aortic valve calcification by inhibiting GABARAP expression
Journal of Army Medical University 2023, 45(16): 1702-1711
Published: 30 August 2023
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Objective

To investigate the effect and potential mechanism of miR-761 on calcified aortic valve disease(CAVD).

Methods

Normal(n=6)and calcified(n=8)valve tissues were collected from Department of Cardiothoracic Surgery of the First Affiliated Hospital of Chongqing Medical University between January 2022 and January 2023. The changes of autophagy, osteogenesis, GABARAP protein or miR-761 expression in calcified valve tissues were detected by Western blotting, immunohistochemical staining and RT-qPCR. Double luciferase assay verified miR-761 binding to GABARAP 3′-UTR region. The phenotypes of porcine aortic valve interstitial cells(pVICs)were identified by immunofluorescence assay. pVICs were transfected with miR-761 mimic, inhibitor and corresponding control to construct pVICs cell lines with over-expression or knockdown of miR-761. After adding GFP-LC3 adenovirus, the number of autophagosomes was observed. Western blotting, alkaline phosphatase staining and alizarin red S staining were used to detect the osteogenic differentiation of pVICs before and after osteogenic medium(OM)treatment.

Results

Compared with normal tissues, the prdein levels of Beclin 1, ULK1, α-SMA, RUNX2 and GABARAP were up-regulated in calcified valve tissue tissues, while the levels of p62 and miR-761 were down-regulated(P<0.05). Dual luciferase assay verified the binding of miR-761 to GABARAP 3′-UTR region(P<0.05). The isolated pVICs expressed interstitial cell markers(α-SMA, Vimentin). Confocal microscopy showed that overexpression of miR-761 reduced autophagosome production in pVICs. The protein results, alkaline phosphatase staining and alizarin red S staining showed that knockdown of miR-761 significantly increased the expression of GABARAP in pVICs, significantly decreased the expressions of OPN, α-SMA, CollagenⅠand RUNX2(P<0.05), and inhibited the calcium salt deposition in the cells induced by OM.

Conclusion

MiR-761 may inhibit autophagy and promote cardiac valve calcification by inhibiting GABARAP expression.

Open Access Full Length Article Issue
Mitophagy deficiency activates stimulator of interferon genes activation and aggravates pathogenetic cardiac remodeling
Genes & Diseases 2024, 11(6): 101074
Published: 02 September 2023
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Stimulator of interferon genes (STING) has recently been found to play a crucial role in cardiac sterile inflammation and dysfunction. The role of stimulator of interferon genes (STING) in cardiac sterile inflammation and dysfunction has been recently discovered. This study aims to examine the involvement of STING in pathological cardiac remodeling and the mechanisms that govern the activation of the STING pathway. To investigate this, transverse aortic constriction (TAC) was performed on STING knockout mice to induce pressure overload-induced cardiac remodeling. Subsequently, cardiac function, remodeling, and inflammation levels were evaluated. The STING pathway was found to be activated in the pressure overload-stressed heart and angiotensin Ⅱ (Ang Ⅱ)-stimulated cardiac fibroblasts. Loss of STING expression led to a significant reduction in inflammatory responses, mitochondrial fragmentation, and oxidative stress in the heart, resulting in attenuated cardiac remodeling and dysfunction. Furthermore, the exacerbation of pressure overload-induced STING-mediated inflammation and pathological cardiac remodeling was observed when mitophagy was suppressed through the silencing of Parkin, an E3 ubiquitin ligase. Taken together, these findings indicate that STING represents a newly identified and significant molecule implicated in the process of pathological cardiac remodeling and that mitophagy is an upstream mechanism that regulates STING activation. Targeting STING may therefore provide a novel therapeutic strategy for pathological cardiac remodeling and heart failure.

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