Background Pathological cardiac hypertrophy is a major contributor of heart failure (HF), which seriously threatens human’s health world widely. Deregulation of m6A RNA methylation, and m6A methyltransferases and de-methyltransferases have been demonstrated to act essential roles in cardiac hypertrophy and HF. Here, we studied the potential roles and its underlying mechanisms of m6A Reader YTHDF proteins in HF. In this study, we constructed HF mouse model by transverse aortic constriction surgery. Primary cardiomyocytes were isolated and stimulated with isoproterenol (ISO) or phenylephrine (PHE) to induce myocardial hypertrophy. Results Through single-cell RNA-seq analysis, immunofluorescent staining, HE staining, Western blotting, and real time-PCR detections, we found that YTHDF2 mRNA and protein level, but not YTHDF1 or YTHDF3, was significantly increased during HF development. YTHDF2 overexpression could efficiently alleviate cardiac hypertrophy. Furthermore, through immunoprecipitation accompanied with mass spectrometry analysis, Gene Ontology (GO) analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, we found that ISO stimulation did not evidently affect YTHDF2-interacting proteins. However, ISO or PHE stimulation significantly increased YTHDF2 protein interacting with Myh7 (beta-myosin heavy chain) mRNA, an important cardiac hypertrophy marker, in an m6A-dependent manner. Knockdown of Myh7 or deletion of the YTH domain of YTHDF2 reversed the protective effects of YTHDF2 on cardiac hypertrophy. Finally, we found that ISO or PHE stimulation promoted YTHDF2 protein expression through enhancing Ythdf2 mRNA stability in an m6A-dependent manner in cardiomyocytes. Conclusions Overall, our results indicate that the m6A Reader YTHDF2 suppresses cardiac hypertrophy via Myh7 mRNA decoy in an m6A-dependent manner. This study highlights the functional importance of YTHDF2-dependent cardiac m6A mRNA regulation during cardiac hypertrophy, and provides a novel mechanistic insight into the therapeutic mechanisms of YTHDF2.

Background: The aim of this study was to evaluate comparatively the effectiveness of computed tomography-guided percutaneous radiofrequency ablation (CT-PRFA) for primary non-small cell lung cancer (NSCLC) and lung metastases from hepatocellular carcinoma (HCC) and to explore the potential miRNA mechanisms for the efficacy of CT-PRFA. Methods: 14 patients pathologically diagnosed with NSCLC and 12 patients with lung metastases from HCC were enrolled in the study and underwent CT-PRFA. Clinical outcomes were compiled on the basis of review of medical records, imaging follow-up reports, and any biopsy-proved residual or recurrent disease. Real-time RT-PCR was used to quantify the selected miRNAs known to be play key roles in lung cancer. Results: A total of 21 tumors were treated with umbrella-tip electrodes and spiral-tip electrodes were used for the remaining 8 tumors. The median follow-up was 13.5 months (range, 3-30 months) and no patient was lost to follow-up. The rate of technique efficacy for primary tumors was ∼93% (13 of 14). Treatment was successful in 11 out of 12 (91.7%) lung metastases patients. Overall survival rate was 80.8% at 2 years, and cancer-specific survival rate was 100% at 2 years. The tumor-free survival was 69.2% at 1 year and 26.9% at 2 years. Before PRFA, tumor suppressor let-7a and miR-34a were downregulated whereas oncomiR miR-21 was upregulated in primary tumors, and let-7a and miR-126 levels were downregulated whereas oncomiRs miR-21, miR-155 and miR-17-5p/miR-20b levels were upregulated in secondary tumors. This abnormal expression was normalized by CT-PRFA. Most notably, CT-PRFA failed to normalize the deregulated miRNAs in the non-survivors. Conclusions: CT-PRFA is a effective treatment for primary NSCLCs and secondary lung tumors from HCC and the efficacy may be related to its ability to normalize deregulated expression of miRNAs: upregulating tumor suppressor miRNAs and downregulating oncomiRs.

N6-methyladenosine (m6A) is a eukaryotic messenger RNA modification catalyzed by methyltransferase-like 3 (METTL3), which is involved in various developmental and disease processes. However, the connection between the epigenetic modification of m6A and glucose metabolism during osteogenesis is still unclear. Here, we show that interference with METTL3 in dental pulp stem cells (DPSCs) inhibits cell proliferation and osteogenic differentiation. Moreover, transcriptome sequencing and metabolic testing were used to explore the mechanism between glucose metabolism and m6A modification in METTL3-knockdown DPSCs. Methylated RNA immunoprecipitation–quantitative polymerase chain reaction and RNA stability assays were used to determine the target genes of METTL3. Mechanistically, METTL3 directly interacts with ATP citrate lyase (ACLY) and a mitochondrial citrate transporter (SLC25A1) and then further affects the glycolytic pathway. M6A-mediated ACLY and SLC25A1 stability depends on the m6A readers IGF2BP2 and IGF2BP2/3, respectively. Our experiments uncovered the potential molecular mechanism of epigenetic modification in osteogenic differentiation, providing new ideas for the clinical application of stem cells and the intervention of metabolic bone diseases.

Calcific aortic valve disease (CAVD) is highly prevalent in our aging world and has no effective pharmaceutical treatment. Intense efforts have been made but the underlying molecular mechanisms of CAVD are still unclear. This study was designed to identify the critical genes and pathways in CAVD by bioinformatics analysis. Microarray datasets of GSE12644, GSE51472, and GSE83453 were obtained from Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified and functional and pathway enrichment analysis was performed. Subsequently, the protein–protein interaction network (PPI) was constructed with Search Tool for the Retrieval of Interacting Genes and was visualized with Cytoscape to identify the most significant module. Hub genes were identified by Cytoscape plugin cytoHubba. A total of 179 DEGs, including 101 upregulated genes and 78 downregulated genes, were identified. The enriched functions and pathways of the DEGs include inflammatory and immune response, chemotaxis, extracellular matrix (ECM) organization, complement and coagulation cascades, ECM receptor interaction, and focal adhesion. The most significant module in the PPI network was analyzed and genes among it were mainly enriched in chemotaxis, locomotory behavior, immune response, chemokine signaling pathway, and extracellular space. In addition, DEGs, with degrees ≥ 10 and the top 10 highest Maximal Chique Centrality (MCC) score, were identified as hub genes. CCR1, MMP9, VCAM1, and ITGAX, which were of the highest degree or MCC score, were manually reviewed. The DEGs and hub genes identified in the present study help us understand the molecular mechanisms underlying the pathogenesis of CAVD and might serve as candidate therapeutic targets for CAVD.

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