Upregulation of Long Noncoding RNA FGD5-AS1 Ameliorates Myocardial Ischemia/Reperfusion Injury via MicroRNA-106a-5p and MicroRNA-106b-5p

Role of non-coding RNAs in the pathogenesis of viral myocarditis

Viral myocarditis (VMC) is a common inflammatory disease of the myocardium that is characterized mainly by inflammatory cell infiltration and cardiomyocyte necrosis. Coxsackievirus B3 (CVB3) is a common cause of VMC, although major progress has been made in the treatment of VMC, the long-term prognosis is still not ideal and further research is needed. Non-coding RNAs (ncRNAs) are RNA molecules without coding functions and include microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), which play extensive regulatory roles in gene expression; however, their mechanisms of action in CVB3-induced VMC remain incompletely understood. Here, we review the currently known roles of various ncRNAs in CVB3-induced VMC models, with a focus on cell death, inflammation and viral replication, with the aim of providing a reference for their therapeutic or vaccine development for the treatment of VMC.

LncRNA NAV2-AS2 is critical for fibroblast-to-myofibroblast transition and cardiac fibrosis

Cardiac fibrosis is a key feature of cardiac remodeling in advanced stages of various cardiovascular diseases. Long non-coding RNAs (lncRNAs) have been shown to play a critical role in the pathogenesis of cardiac fibrosis. The present study uncovered lncRNA NAV2-AS2 as a newfound regulator of cardiac fibrosis, governing fibroblast proliferation and fibroblast-to-myofibroblast transition (FMT). We demonstrate that the expression of NAV2-AS2 is decreased in both fibrotic human heart and murine models of cardiac fibrosis. Knockdown of NAV2-AS2 is sufficient for the induction of fibroblast proliferation and FMT, whereas overexpression of NAV2-AS2 produces the opposite changes. Most importantly, fibroblast-specific transgenic overexpression of NAV2-AS2 in vivo by systemically delivering adeno-associated virus serotype 9 (AAV9) vector rescues cardiac fibrosis and dysfunction induced by both transverse aortic constriction (TAC) and myocardial infarction (MI), whereas knockout of NAV2-AS2 in mice exacerbates the cardiac damage. Mechanistically, NAV2-AS2 is found to act as a competing endogenous RNA (ceRNA) by sponging and inhibiting miR-31. NAV2-AS2 positively regulates Apelin, a critical repressor of proliferation and FMT, by binding to miR-31 and suppressing its degradation of Apelin. Silencing Apelin or overexpression of miR-31 abolishes the anti-fibrotic effects of NAV2-AS2. Additionally, circulating levels of NAV2-AS2 are reduced in the serum of heart failure patients. Collectively, NAV2-AS2 alleviates cardiac fibrosis and improves cardiac function by targeting the miR-31/Apelin axis and can be a potential predictor for heart failure.

Progress on long non-coding RNAs in calcific aortic valve disease

Calcific aortic valve disease (CAVD) is a common cardiovascular condition in the elderly population. The aortic valve, influenced by factors such as endothelial dysfunction, inflammation, oxidative stress, lipid metabolism disorders, calcium deposition, and extracellular matrix remodeling, undergoes fibrosis and calcification, ultimately leading to stenosis. In recent years, long non-coding RNAs (lncRNAs) have emerged as significant regulators of gene expression, playing crucial roles in the occurrence and progression of various diseases. Research has shown that lncRNAs participate in the pathological process underlying CAVD by regulating osteogenic differentiation and inflammatory response of valve interstitial cells. Specifically, lncRNAs, such as H19, MALAT1, and TUG1, are closely associated with CAVD. Some lncRNAs can act as miRNA sponges, form complex regulatory networks, and modulate the expression of calcification-related genes. In brief, this review discusses the mechanisms and potential therapeutic targets of lncRNAs in CAVD.

MiR-106a targets ATG7 to inhibit autophagy and angiogenesis after myocardial infarction

BACKGROUND

Myocardial infarction (MI) is an acute condition in which the heart muscle dies due to the lack of blood supply. Previous research has suggested that autophagy and angiogenesis play vital roles in the prevention of heart failure after MI, and miR-106a is considered to be an important regulatory factor in MI. But the specific mechanism remains unknown. In this study, using cultured venous endothelial cells and a rat model of MI, we aimed to identify the potential target genes of miR-106a and discover the mechanisms of inhibiting autophagy and angiogenesis.

METHODS

We first explored the biological functions of miR-106a on autophagy and angiogenesis on endothelial cells. Then we identified ATG7, which was the downstream target gene of miR-106a. The expression of miR-106a and ATG7 was investigated in the rat model of MI.

RESULTS

We found that miR-106a inhibits the proliferation, cell cycle, autophagy and angiogenesis, but promoted the apoptosis of vein endothelial cells. Moreover, ATG7 was identified as the target of miR-106a, and ATG7 rescued the inhibition of autophagy and angiogenesis by miR-106a. The expression of miR-106a in the rat model of MI was decreased but the expression of ATG7 was increased in the infarction areas.

CONCLUSION

Our results indicate that miR-106a may inhibit autophagy and angiogenesis by targeting ATG7. This mechanism may be a potential therapeutic treatment for MI.

Diagnostic and prognostic value of plasma miR-106a-5p levels in patients with acute heart failure

BACKGROUND

It is essential to find reliable biomarkers for early diagnosis and prognosis of acute heart failure (AHF) for its mitigation. Currently, increasing attention is paid to the role of microRNAs (miRNAs/miRs) as diagnostic or prognostic markers for cardiovascular diseases. Since plasma miR-106a-5p has been observed to be downregulated in AHF, its value in the diagnosis and prognostic assessment of AHF deserves further exploration. Accordingly, this study analyzed the diagnostic and prognostic value of plasma miR-106a-5p in AHF patients.

METHODS

Prospectively, this study included 127 AHF patients who met the 2021 European Society of Cardiology Guidelines and 127 control individuals. Plasma miR-106a-5p levels were determined with RT-qPCR. Spearman correlation analysis was performed to evaluate the correlation of plasma miR-106a-5p levels with NT-proBNP and hs-CRP levels in AHF patients. All AHF patients were followed up for 1 year and allocated into poor and good prognosis groups, and plasma miR-106a-5p levels were compared. The diagnostic and prognostic value of plasma miR-106a-5p for AHF was assessed with a receiver-operating characteristic curve.

RESULTS

Plasma miR-106a-5p was lowly expressed in AHF patients versus controls (0.53 ± 0.26 vs. 1.09 ± 0.46) and showed significant negative correlations with NT-proBNP and hs-CRP levels. Plasma miR-106a-5p level < 0.655 could assist in AHF diagnosis. Plasma miR-106a-5p levels were markedly lower in poor-prognosis AHF patients than in good-prognosis patients. Plasma miR-106a-5p level < 0.544 could assist in predicting poor prognosis in AHF patients.

CONCLUSION

Plasma miR-106a-5p is downregulated in AHF patients and could assist in diagnosis and poor prognosis prediction of AHF.

Linc00657 promoted pyroptosis in THP-1-derived macrophages and exacerbated atherosclerosis via the miR-106b-5p/TXNIP/NLRP3 axis

Long intergenic non-coding RNA 00657 (linc00657) is involved in various diseases, whereas its role in atherosclerosis (AS) development remains inconclusive. This study was designed to investigate the effects and underlying mechanisms of linc00657 in atherogenesis. The results showed that ox-LDL treatment significantly induced pyroptosis in human THP-1-derived macrophages. The secretion levels of LDH and pro-inflammatory factors were markedly enhanced, and the integrity of plasma membranes was disrupted in ox-LDL-treated THP-1-derived macrophages. These effects were significantly compensated after transfection with linc00657 siRNA and became more evident by linc00657 overexpression. Moreover, the effects of linc00657 overexpression on pyroptosis of THP-1-derived macrophages can also be robustly reversed by TXNIP knockdown or miR-106b-5p mimics transfection. Mechanistically, linc00657 enhanced TXNIP expression by competitively binding to miR-106b-5p, promoting NLRP3 inflammasome activation. Finally, we found that linc00657 overexpression significantly increased the expression of pyroptosis-related factors and decreased miR-106b-5p level in the aorta of high-fat-diet-fed apoE-/- mice. Furthermore, linc00657 up-regulation enlarged the plaque area, exacerbated plasma lipid profile, and increased pro-inflammatory cytokines levels in the serum, effects that were reversed by injection of miR-106b-5p agomir. This evidence indicated that linc00657 stimulated macrophage pyroptosis and aggravated the progression of AS via the miR-106b-5p/TXNIP/NLRP3 pathway.

Knockdown of Mmu-circ-0001380 Attenuates Myocardial Ischemia/Reperfusion Injury via Modulating miR-106b-5p/Phlpp2 Axis

Myocardial ischemia/reperfusion (MI/R) injury induces myocardial damage and dysfunction. Increasing evidence has confirmed that circular RNAs (circRNAs) play crucial roles in regulating MI/R. Mmu-circ-0001380 has identified to be highly expressed in myocardium of MI/R mouse model. However, its biological function and molecular mechanism in MI/R injury are still unclear. Here, we demonstrated that knockdown of cric-0001380 attenuated myocardial injury of MI/R mice. In vitro, silence of circ-0001380 significantly enhanced viability, and inhibited apoptosis and oxidative stress in HL-1 cells under oxygen-glucose deprivation/reoxygenation (OGD/R). Mmu-miR-106b-5p interacted with circ-0001380, and suppressed the expression of pleckstrin homology domain and leucine rich repeat protein phosphatase 2 (Phlpp2). The miR-106b-5p/Phlpp2 axis mediated the effect of circ-0001380 on OGD/R-induced apoptosis through regulating the phosphorylation of p38, and further involved in regulating the viability and oxidative stress of HL-1 cells. In conclusion, circ-0001380 downregulation relieves MI/R injury via regulating the miR-106b-5p/Phlpp2 axis. The present study indicates that mmu-circ-0001380 exacerbates the myocardial ischemia/reperfusion injury through modulating the miR-106b-5p/Phlpp2 axis in vitro and in vivo.

Integrated analysis of immune- and apoptosis-related lncRNA-miRNA-mRNA regulatory network in children with Henoch Schönlein purpura nephritis

BACKGROUND

Long noncoding RNAs (lncRNAs) play important roles in the regulation of immunological and apoptotic function. This study aimed to explore the critical immune- and apoptosis-related lncRNAs in the occurrence and development of Henoch-Schönlein purpura nephritis (HSPN) in children.

METHODS

Differential analysis was employed to identify the differentially expressed lncRNAs, as well as the immune- and apoptosis-related mRNAs in children with HSPN. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to validate the immunological and apoptotic roles of the differentially expressed immune- and apoptosis-related lncRNAs and mRNAs. Spearman's correlation analysis was performed to analyze the differentially expressed lncRNAs and immune- and apoptosis-related messenger RNAs (mRNAs). Based on the competing endogenous RNA (ceRNA) mechanism, the immune- and apoptosis-related lncRNA-microRNA (miRNA)-mRNA regulatory network was then constructed in children with HSPN. The expression levels of the lncRNAs in the lncRNA-miRNA-mRNA regulatory network were further confirmed by quantitative real-time polymerase chain in the peripheral blood samples of children with HSPN.

RESULTS

By intersecting the differentially expressed immune-related and apoptosis-related genes through GO and KEGG analyses, a total of 43 genes were identified in children with HSPN, and 100 lncRNAs highly correlated with the above genes were identified by correlation analysis. The immune- and apoptosis-related lncRNA-miRNA-mRNA regulatory network was then established based on ceRNA mechanism. Dysregulation of a total of 11 lncRNAs were discovered, including upregulated SNHG3, LINC00152, TUG1, GAS5, FGD5-AS1, DLEU2, and SCARNA9; and downregulated SNHG1, NEAT1, DISC1-IT1, and PVT1. The validation conducted in the clinical samples also suggested that the above lncRNAs in the specific regulatory network may act as potential biomarkers with prognosis in children with HSPN.

CONCLUSIONS

LncRNAs may play essential regulatory roles in the occurrence and development of HSPN in children, and the immune- and apoptosis-related lncRNA-miRNA-mRNA regulatory network might be the underlying molecular mechanism that dissects the disease pathogenesis. In addition, the dysregulated lncRNAs in the regulatory network may be novel biomarkers for the diagnosis and therapy of HSPN in children.

Dexmedetomidine promotes cell proliferation and inhibits cell apoptosis by regulating LINC00982 and activating the phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) signaling in hypoxia/reoxygenation-induced H9c2 cells

Previous studies showed dexmedetomidine (DEX) could alleviate myocardial ischemia/reperfusion injury (MIRI). Nevertheless, the mechanisms by which DEX alleviated MIRI remain to be determined. Our results demonstrated that DEX reversed hypoxia/reoxygenation (H/R)-induced decreased proliferation, and enhanced LINC00982 level, apoptosis, and inflammation in H9c2 cells. Moreover, LINC00982 overexpression attenuated the DEX-mediated protective effect of H9c2 cells under H/R. In addition, DEX upregulated p-phosphoinositide-3-kinase (p-PI3K) and p-protein kinase B (p-AKT) levels, and the silencing of LINC00982 further enhanced this effect in H/R-induced H9c2 cells. Furthermore, LINC00982 deletion enhanced the protective effect of DEX on H9c2 cells under H/R condition, while PI3K inhibitor, LY294002, obviously reversed this phenomenon. In sum, our work determined that DEX could suppress cell apoptosis and inflammation in H/R-triggered H9c2 through downregulating LINC00982 and activating PI3K/AKT signaling.

lncRNA FGD5-AS1 Regulates Bone Marrow Stem Cell Proliferation and Apoptosis by Affecting miR-296-5p/STAT3 Axis in Steroid-Induced Osteonecrosis of the Femoral Head

Background

Osteonecrosis of the femoral head (ONFH) is a common hip joint disease, which is more harmful and seriously affects the lives of patients. This study aims to clarify the regulatory mechanism of lncRNA FGD5-AS1 in ONFH.

Methods

The expression of the protein and mRNA was detected by RT-qPCR and Western blot assay. The regulatory mechanism of lncRNA FGD5-AS1 was detected by the dual-luciferase reporter assay, CCK-8 assay, and flow cytometry assay.

Results

Dex can inhibit cell proliferation and differentiation and induce apoptosis in hBMSCs in a dose-dependent manner. Overexpression of lncRNA FGD5-AS1 promoted cell proliferation and restrained apoptosis in Dex-treated hBMSCs. In addition, lncRNA FGD5-AS1 acts as a sponge for miR-296-5p. Also, miR-296-5p directly targets STAT3. More importantly, miR-296-5p and STAT3 can affect the function of lncRNA FGD5-AS1 in Dex-treated hBMSCs.

Conclusion

lncRNA FGD5-AS1 promotes cell proliferation and inhibits apoptosis in steroid-induced ONFH through acting as a sponge for miR-296-5p and upregulation of STAT3.