刘勇
云南省阜外心血管病医院 心外科一病区
BACKGROUND:Cardiac-resident or -enriched microRNAs (miRNAs) could be released into the bloodstream becoming circulating cardiac miRNAs, which are increasingly recognized as non-invasive and accessible biomarkers of multiple heart diseases. However, dilated cardiomyopathy (DCM)-associated circulating miRNAs (DACMs) and their roles in DCM pathogenesis remain largely unexplored.METHODS:Two human cohorts, consisting of healthy individuals and DCM patients, were enrolled for serum miRNA sequencing (10 vs. 10) and quantitative polymerase chain reaction validation (46 vs. 54), respectively. Rigorous screening strategy was enacted to define DACMs and their potentials for diagnosis. DCM mouse model, different sources of cardiomyocytes, adeno-associated virus 9 (AAV9), gene knockout, RNAscope miRNA in situ hybridization, mRFP-GFP-LC3B reporter, echocardiography and transmission electron microscopy were adopted for mechanistic explorations.RESULTS:Serum miRNA sequencing revealed a unique expression pattern for DCM circulating miRNAs. DACMs miR-26a-5p, miR-30c-5p, miR-126-5p and miR-126-3p were found to be depleted in DCM circulation as well as heart tissues. Their expressions in circulation and heart tissues were proven to be correlated significantly, and a combination of these miRNAs was suggested potential values for DCM diagnosis. FOXO3, a predicted common target, was experimentally demonstrated to be co-repressed within cardiomyocytes by these DACMs except miR-26a-5p. Delivery of a combination of miR-30c-5p, miR-126-5p and miR-126-3p into the murine myocardium via AAV9 carrying an expression cassette driven by cTnT promoter, or cardiac-specific knockout of FOXO3 (Myh6-CreERT2 , FOXO3 flox+/+ ) dramatically attenuated cardiac apoptosis and autophagy involved in DCM progression. Moreover, competitively disrupting the interplay between DACMs and FOXO3 mRNA by specifically introducing their interacting regions into murine myocardium crippled the cardioprotection of DACMs against DCM.CONCLUSIONS:Circulating cardiac miRNA-FOXO3 axis plays a pivotal role in safeguarding against myocardial apoptosis and excessive autophagy in DCM development, which may provide serological cues for DCM non-invasive diagnosis and shed light on DCM pathogenesis and therapeutic targets.
Clinical and translational medicine 2023
BACKGROUND The protein NKX2-5 affects mammalian heart development. In mice, the disruption of Nkx2-5 has been associated with arrhythmias, abnormal myocardial contraction, abnormal cardiac morphogenesis, and death. However, the details of the mechanisms are unclear. This study was designed to investigate them. MATERIAL AND METHODS Rat cardiomyocytes from the H9c2 cell line were used in our study. First, we knocked down Nkx2-5 in the H9c2 cells and then validated consequent changes in cell proliferation and migration. We then used RNA sequencing to determine the changes in transcripts. Finally, we validated these results by quantitative reverse transcription-polymerase chain reaction. RESULTS We confirmed that Nkx2-5 regulates the proliferation and migration of H9c2 cells. In our experiments, Nkx2-5 regulated the expression of genes related to proliferation, migration, heart development, and disease. Based on bioinformatics analysis, knockdown of Nkx2-5 caused differential expression of genes involved in cardiac development, calcium ion-related biological activity, the transforming growth factor (TGF)-ß signaling pathway, pathways related to heart diseases, the MAPK signaling pathway, and other biological processes and signaling pathways. CONCLUSIONS Nkx2-5 may regulate proliferation and migration of the H9c2 cells through the genes Tgfb-2, Bmp10, Id2, Wt1, Hey1, and Cacna1g; rno-miR-1-3p; the TGF‑ß signaling pathway; the MAPK signaling pathway; as well as other genes and pathways.
Medical science monitor : international medical journal of experimental and clinical research 2020
