Project description:Cardiac hypertrophy, a precursor for heart failure, requires increased translation. However, little is known of the mechanisms that regulate translation in hypertrophy. Members of the 2-oxoglutarate-dependent dioxygenase family regulate several aspects of gene expression, including translation. An important member of this family is OGFOD1. Here, we show OGFOD1 accumulates in failing human hearts. Upon OGFOD1 deletion, murine hearts showed transcriptomic and proteomic changes, with only 21 factors (0.6%) changing in the same direction at both the mRNA and protein levels. Additionally, OGFOD1-KO mice were protected from induced hypertrophy, supporting a role for OGFOD1 in the cardiac response to chronic stress.
Project description:Pathological growth of cardiomyocytes during hypertrophy is characterized by excess protein synthesis; however, the regulatory mechanism remains largely unknown. Using a neonatal rat ventricular myocyte (NRVMs) model, here we find that the expression of nucleosome assembly protein 1 like 5 (Nap1l5) is upregulated in phenylephrine (PE)-induced hypertrophy. Knockdown of Nap1l5 expression by siRNA significantly blocks cell size enlargement and pathological gene induction after PE treatment. In contrast, Adenovirus-mediated Nap1l5 overexpression significantly aggravates the pro-hypertrophic effects of PE on NRVMs. RNA-seq analysis reveals that Nap1l5 knockdown reverses the pro-hypertrophic transcriptome reprogramming after PE treatment. Whereas immune response is dominantly enriched in the upregulated genes, oxidative phosphorylation, cardiac muscle contraction and ribosome related pathways are remarkably enriched in the down-regulated genes. Although PRC2 and PRC1 are involved in Nap1l5-mediated gene regulation, Nap1l5 does not directly alter the levels of global histone methylations. However, puromycin incorporation assay shows that Nap1l5 is both necessary and sufficient to drive the increased protein synthesis rate in cardiomyocyte hypertrophy. This is attributable to a direct regulation of ribosome assembly by Nap1l5. Our findings demonstrate a previously unrecognized role of Nap1l5 in translation control during cardiac hypertrophy.
Project description:In this study we provide the gene expression profiles and MISO analyses for alternative splicing events such as exon skipping in wildtype versus OGFOD1 (oxoglutarate, glucose and iron dependent protein 1)-knock-out iPSC-derived cardiomyocytes, we further compare the profiles to wildtype which were treated with a drug inhibiting α-ketoglutarate-dependent hydroxylases (dimethyloxalylglycine) versus vehicle control. Altered translation and splicing processes play a role in differentiation processes and have been shown to be involved in disease progression in e.g. heart failure. OGFOD1 is a ribosomal prolyl-hydroxylase and which influences translation, here we show its further importance in cardiac differentiation and alternative splicing.
Project description:Pathological cardiac hypertrophy is featured by enhanced protein synthesis. Translation inhibition is effective in treating cardiac hypertrophy, yet with systematic side effect. We identified a cardiac-enriched LncRNA CARDINAL, when deleted, exacerbate transaortic constriction (TAC) induced hypertrophy.
Project description:Pathological cardiac hypertrophy is featured by enhanced protein synthesis. Translation inhibition is effective in treating cardiac hypertrophy, yet with systematic side effect. We identified a cardiac-enriched LncRNA CARDINAL, when over-expressed in cardiomyocyte using AAV9 driven by cTNT promoter, ameliorate transaortic constriction (TAC) induced hypertrophy.
Project description:MYC enhances protein synthesis by regulating genes involved in ribosome biogenesis and protein translation. Here, we show that MYC-induced protein translation is mediated by the transcription factor aryl hydrocarbon receptor (AHR), which is induced by MYC in colonic cells. AHR promotes protein synthesis by activating the transcription of genes required for ribosome biogenesis and protein translation, including OGFOD1 and NOLC1. Using surface sensing of translation (SUnSET) to measure global protein translation, we found that silencing AHR or its targets diminishes protein synthesis. Therefore, targeting AHR or its downstream pathways could provide a novel approach to limit biomass production in MYC-driven tumors.
Project description:The methyltransferase-like5 (METTL5), which catalyzes m6A in 18S rRNA at position A1832, has been shown to regulate the efficient of mRNA translation in the differentiation of ES cell and the growth of cancer cells. It remains unknown that whether and how METTL5 regulates cardiac hypertrophy. In this study, we generated a mouse model (METTL5-cKO) with cardiac-specific abolishment of METTL5 in vivo. Loss function of METTL5 promotes pressure overload-induced cardiomyocyte hypertrophy and adverse remodeling. The regulatory function of METTL5 in hypertrophic growth of cardiomyocyte were further confirmed with both gain- and loss-of-function approaches in primary isolated cardiomyocytes. Mechanically, METTL5 was identified to modulate the mRNA translation of SUZ12, a core component of PRC2 complex, and further regulate the transcriptome shift during cardiac hypertrophy. Therefore, our study uncover an important translational regulator of cardiac hypertrophy.