Project description:We compared the transcriptome modified by siRNA-mediated cardiac hypertrophy associated epigenentic regulator (Chaer) with negative control siRNA treated neonatal rat ventricular myocytes with or without phenylephrine treatment. The results suggest that Chaer knockdown broadly blocks the phenylephrine-induced hypertrophic programming of the transcriptome. Transcripts profiles from neonatal rat ventricular myocytes with or without phenylephrine and with or without Chaer-specific siRNA compared to negative control siRNA
Project description:Neonatal rat ventricular myocytes cultured for 48 hours without stimulation, in the presence of twenty micromolar phenylephrine, or in the presence of one micromolar PAMH. Keywords = Rattus Keywords = Ventricular Myocytes Keywords = Cardiomyocytes Keywords = Hypertrophy Keywords = Phenylephrine Keywords = PAMH Keywords = 5-hydroxytryptamine Keywords = Pyridine Keywords: repeat sample
Project description:We compared the transcriptome modified by siRNA-mediated cardiac hypertrophy associated epigenentic regulator (Chaer) with negative control siRNA treated neonatal rat ventricular myocytes with or without phenylephrine treatment. The results suggest that Chaer knockdown broadly blocks the phenylephrine-induced hypertrophic programming of the transcriptome.
Project description:Neonatal rat ventricular myocytes cultured for 48 hours without stimulation, in the presence of twenty micromolar phenylephrine, or in the presence of one micromolar PAMH.
Project description:Zinc dyshomeostasis has been involved in the pathogenesis of cardiac hypertrophy; however, the dynamic regulation of intracellular zinc and its downstream signaling in cardiac hypertrophy remain largely unknown. Here we screened ZIP (SLC39) family members that were responsible for zinc uptake in a phenylephrine (PE)-induced cardiomyocyte hypertrophy model. We found that Slc39a2 was the only member that was altered at mRNA level by PE treatment in neonatal rat ventricular myocytes (NRVMs), but its protein level was not affected. Zincpyr1 staining showed a significant decrease in zinc uptake after PE treatment or after Slc39a2 knockdown in NRVMs, indicating an inhibition of its transport activity during hypertrophy. Slc39a2 deficiency caused spontaneous hypertrophy in NRVMs, and further exacerbated the hypertrophic responses after PE treatment. RNA sequencing analysis confirmed a largely aggravated pro-hypertrophic transcriptome reprogramming after Slc39a2 knockdown. Interestingly, the innate immune pathways, including NOD signaling, TOLL-like receptor, NFB, and IRFs, were substantially enriched after Slc39a2 knockdown. Whereas IRF7, the most sensitive among all IRFs, did not mediate the effect of Slc39a2 in hypertrophy, pro-hypertrophy phosphorylations of NFB and STAT3 were significantly enhanced after Slc39a2 knockdown, in parallel with degradation of IkBα protein. Our data demonstrate that SLC39A2-mediated zinc homeostasis contributes to the remodeling of innate immune signaling in cardiomyocyte hypertrophy, and provide novel insights into the pathogenesis of heart failure and its treatment.
Project description:Excess protein synthesis is the major pathological manifestation of cardiac hypertrophy; however, the underlying mechanism remains elusive. Here we found that a SAM transporter Slc25a26 translocated to mitochondria during cardiac hypertrophy. Silencing Slc25a26 aggravated phenylephrine-induced cardiomyocyte hypertrophy in neonatal rat ventricular myocytes. Transcriptome analysis revealed a specific regulation of ribosome genes by Slc25a26. Puromycin incorporation assay showed a negative regulation of protein synthesis rate by Slc25a26. The translational regulation was independent of ribosome assembly, but abolished by mTOR inhibitor rapamycin. Administration of SAM, or silencing Samtor, reversed the inhibitory impact of Slc25a26 on protein synthesis. AAV9-mediated Slc25a26 overexpression in mouse heart increased the SAM level in mitochondria, but reduced that in nucleus and cytoplasm. Transaortic-constriction-induced hypertrophic pathologies, including pathological gene induction, cardiomyocyte enlargement, myocardial remodeling and heart dysfunction were significantly alleviated by Slc25a26 overexpression. Our data demonstrate a crucial role of subcellular SAM homeostasis in translational control during cardiac hypertrophy.
Project description:Heart failure is a leading cause of death in US. Hypertension is one of the most important risk factor of heart failure. In the presence of high blood pressure, the heart manifests hypertrophic growth to ameliorate ventricular wall stress. This once adaptive response may progress into decompensation and heart failure. The precise mechanisms governing this transition remain elusive. Here, we aimed to identify novel signaling pathways in cardiac hypertrophic growth. Primary neonatal rat ventricular myocytes (NRVMs) were isolated from 1-2 days old rats and treated with phenylephrine or IGF-1. Total RNA was isolated for RNA-seq analysis.
