Cardiac-specific β-catenin deletion dysregulates energetic metabolism and mitochondrial function in perinatal cardiomyocytes
Ontology highlight
ABSTRACT: β-Catenin signaling pathway regulates cardiomyocytes proliferation and differentiation, though its involvement in metabolic regulation of cardiomyocytes remains unknown. We used one-day-old mice with cardiac-specific knockout of β-catenin and neonatal rat ventricular myocytes treated with β-catenin inhibitor to investigate the role of β-catenin metabolism regulation in perinatal cardiomyocytes. Transcriptomics of perinatal β-catenin-ablated hearts revealed a dramatic shift in the expression of genes involved in metabolic processes. Further analysis indicated an inhibition of lipolysis and glycolysis in both in vitro and in vivo models. Finally, we showed that β-catenin deficiency leads to mitochondria dysfunction via the downregulation of Sirt1/PGC-1α pathway. We conclude that cardiac-specific β-catenin ablation disrupts the energy substrate shift that is essential for postnatal heart maturation, leading to perinatal lethality of homozygous β-catenin knockout mice.
Project description:Exclusion of Parkin from mitochondria of perinatal cardiomyocytes interrupts structural and molecular transformations essential to normal perinatal-adult mitochondrial replacement. mRNA-sequencing from cardiac total RNA was performed at P1, P21 and 5-week stages of nontransgenic (ntg) and human-Mfn2-overexpressing (Mfn2wt) hearts, and also of tet-off control (tetoff) and human-Mfn2 T111A/S442A-overexpressing (Mfn2AA) hearts.
Project description:The Wnt pathway is a key regulator of embryonic development, cell growth, differentiation, polarity formation, neural development, carcinogenesis, and stem cell self-renewal, and deregulation of the Wnt signalling is associated with many human disease. The central player in the Wnt pathway is β-catenin, A recent study has shown that β-catenin/Tcf/Lef signaling pathway is an essential growth-regulatory pathway in cardiomyocytes. We used DNA microarrays to detail the global trends in gene expression underlying β-catenin-overexpressed cardiomyocytes and identified distinct classes of up- or down-regulated genes during this process. Our findings suggest that β-catenin plays a critical role in regulating cardiac dysfunction at transcriptional level and may provide novel insight into how β-catenin modulates heart diseases. Cardiomyocytes were infected with GFP control or β-catenin adenoviruses for RNA extraction and hybridization on Affymetrix microarrays. We sought to define the effects of β-catenin on the global programme of gene expression in primary cardiomyocytes. To that end, neonatal rat cardiomyocytes were infected with GFP control (G) or β-catenin adenovirus (B) for 24 hours.
Project description:In order to understand the transcriptional regulatory program of cardiomyocytes perinatal transition, we mapped chromatin accessibility, transcription-centered long-range chromatin interactions as well as gene expression in cardiomyocyte undergoing perinatal transition.
Project description:Exclusion of Parkin from mitochondria of perinatal cardiomyocytes interrupts structural and molecular transformations essential to normal perinatal-adult mitochondrial replacement. mRNA-sequencing from cardiac total RNA was performed at P1, P21 and 5-week stages of nontransgenic (ntg) and human-Mfn2-overexpressing (Mfn2wt) hearts, and also of tet-off control (tetoff) and human-Mfn2 T111A/S442A-overexpressing (Mfn2AA) hearts. Libraries from all P1 samples were prepared and analyzed together, and similarly all P21 libraries, and all 5-week libraries together. To facilitate comparison across time points by accounting for batch effect, new libraries were prepared starting from total RNA from selected P21 ntg and 5-week ntg hearts subjected to prior analysis, during the same batch preparation as all P1 samples, and analyzed together. Correction for differences observed between libraries prepared from the same total RNA, but at different times, allows comparison across timepoints.
Project description:In hESCs, Wnt3/β-catenin activity is low and Activin/SMAD signaling ensures NANOG expression to sustain pluripotency. In response to exogenous Wnt3 effectors, Activin/SMADs switch to cooperate with β-catenin and induce mesendodermal differentiation genes. We show here that the HIPPO effector YAP binds to the WNT3 gene enhancer and prevents the gene from being induced by Activin in proliferating hESCs. In the absence of YAP, Activin signaling is sufficient to induce expression of the endogenous Wnt3 cytokine, which stabilizes β-catenin and selectively activates genes required for cardiac mesoderm (ME) formation. Interestingly, Activin-stimulated YAP-knockout hESCs strongly express β-catenin-dependent cardiac mesoderm markers (BAF60c and HAND1), but unlike WT hESCs, fail to express cardiac inhibitor genes (CDX2, MSX1). Accordingly, YAP-/- cells treated with Activin alone can differentiate efficiently to beating cardiomyocytes in culture, bypassing the need for sequential treatment with exogenous Wnt ligand and Wnt inhibitors. Similarly, Activin in combination with small-molecule YAP inhibitors generates beating cardiomyocytes from wild-type hESCs following a one- step protocol. Our findings highlight an unanticipated role of YAP as an upstream regulator of WNT3 to maintain hESC pluripotency in the presence of Activin, and uncover a direct route for the development of human embryonic cardiac mesoderm.
Project description:To date, there have been limited high quality libraries of cardiomyocyte maturation during the perinatal period, in part owing to the difficulty of isolating large perinatal cardiomyocytes. We previously developed a method utilizing large-particle fluorescent activated cell sorting (LP-FACS) to isolate adult cardiomyocytes for single cell RNA-seq (Kannan et al., Circ Res, 2019). We utilize this method to generate a reference of perinatal cardiomyocyte maturation.
Project description:The Wnt pathway is a key regulator of embryonic development, cell growth, differentiation, polarity formation, neural development, carcinogenesis, and stem cell self-renewal, and deregulation of the Wnt signalling is associated with many human disease. The central player in the Wnt pathway is β-catenin, A recent study has shown that β-catenin/Tcf/Lef signaling pathway is an essential growth-regulatory pathway in cardiomyocytes. We used DNA microarrays to detail the global trends in gene expression underlying β-catenin-overexpressed cardiomyocytes and identified distinct classes of up- or down-regulated genes during this process. Our findings suggest that β-catenin plays a critical role in regulating cardiac dysfunction at transcriptional level and may provide novel insight into how β-catenin modulates heart diseases.
Project description:The heart undergoes significant structural, metabolic, gene expression and functional alterations during the perinatal to postnatal transition. While recent studies have identified multiple epigenetic and transcriptional regulators of cardiac maturation, post-transcriptional mechanisms regulating this process remain poorly understood. Neddylation is a post-translational modification that conjugates a small ubiquitin-like protein, NEDD8, to protein substrates via an E1-E2-E3 enzymatic cascade. The goal of this study was to define the role of neddylation in perinatal cardiac development and cardiac maturation. Neddylation was inhibited in adult mouse hearts by cardiac-specific deletion of NAE1 gene, a regulatory subunit of NEDD8 E1 enzyme, or in neonatal cardiomyocytes (CMs) with a pharmacological neddylation inhibitor, MLN4924. The impact on cardiac transcriptome, metabolism, maturation and function was assessed. Mosaic deletion of NAE1 in ~40% neonatal CMs disrupted aspects of maturation, including transverse-tubule formation, cellular hypertrophy and fetal/adult isoform switching, whereas deletion of NAE1 in over 80% CMs led to rapid development of cardiomyopathy and heart failure. Transcriptome analysis demonstrated an association of metabolic derangement with immature cardiomyocyte signature. Biochemical, ultrastructural and metabolomics analyses confirmed downregulation of fatty acid and oxidative phosphorylation genes, deficits in fatty acid utilization, mitochondrial dysfunction, and significantly altered metabolic profiles in NAE1-deficient hearts or MLN4924-treated neonatal CMs. Mechanistically, we found that HIF1α, a transcription factor known to promote glycolysis and suppress oxidative metabolism, is a putative NEDD8 target. Inhibition of neddylation resulted in HIF1α accumulation and activation, which contributed to diminished fatty acid utilization. Taken together, we conclude that neddylation plays a crucial role in CM maturation and postnatal cardiac development through sustaining the glycolytic to oxidative metabolic switch in perinatal hearts.