Project description:To further characterize the downstream targets of uc.323, we performed global microarray analysis after knockdown of uc.323 in cardiomyocytes to gain broad insight into uc.323-mediated transcriptome changes.
Project description:To investigate the changes in T-UCR (transcribed ultraconserved regions) transcription during aortic banding-induced cardiac hypertrophy, we performed lncRNA microarray analysis on the hearts of mice subjected to sham or aortic banding surgery.
Project description:Pressure overload induces a transition from cardiac hypertrophy to heart failure, but its underlying mechanisms remain elusive. Here we reconstruct a trajectory of cardiomyocyte remodeling and clarify distinct cardiomyocyte gene programs encoding morphological and functional signatures in cardiac hypertrophy and failure, by integrating single-cardiomyocyte transcriptome with cell morphology, epigenomic state and heart function. During early hypertrophy, cardiomyocytes activate mitochondrial translation/metabolism genes, whose expression is correlated with cell size and linked to ERK1/2 and NRF1/2 transcriptional networks. Persistent overload leads to a bifurcation into adaptive and failing cardiomyocytes, and p53 signaling is specifically activated in late hypertrophy. Cardiomyocyte-specific p53 deletion shows that cardiomyocyte remodeling is initiated by p53-independent mitochondrial activation and morphological hypertrophy, followed by p53-dependent mitochondrial inhibition, morphological elongation, and heart failure gene program activation. Human single-cardiomyocyte analysis validates the conservation of the pathogenic transcriptional signatures. Collectively, cardiomyocyte identity is encoded in transcriptional programs that orchestrate morphological and functional phenotypes.
Project description:Pressure overload induces a transition from cardiac hypertrophy to heart failure, but its underlying mechanisms remain elusive. Here we reconstruct a trajectory of cardiomyocyte remodeling and clarify distinct cardiomyocyte gene programs encoding morphological and functional signatures in cardiac hypertrophy and failure, by integrating single-cardiomyocyte transcriptome with cell morphology, epigenomic state and heart function. During early hypertrophy, cardiomyocytes activate mitochondrial translation/metabolism genes, whose expression is correlated with cell size and linked to ERK1/2 and NRF1/2 transcriptional networks. Persistent overload leads to a bifurcation into adaptive and failing cardiomyocytes, and p53 signaling is specifically activated in late hypertrophy. Cardiomyocyte-specific p53 deletion shows that cardiomyocyte remodeling is initiated by p53-independent mitochondrial activation and morphological hypertrophy, followed by p53-dependent mitochondrial inhibition, morphological elongation, and heart failure gene program activation. Human single-cardiomyocyte analysis validates the conservation of the pathogenic transcriptional signatures. Collectively, cardiomyocyte identity is encoded in transcriptional programs that orchestrate morphological and functional phenotypes.
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.