RESUMO
Hematopoietic mutations in epigenetic regulators like DNA methyltransferase 3 alpha (DNMT3A), play a pivotal role in driving clonal hematopoiesis of indeterminate potential (CHIP), and are associated with unfavorable outcomes in patients suffering from heart failure (HF). However, the precise interactions between CHIP-mutated cells and other cardiac cell types remain unknown. Here, we identify fibroblasts as potential partners in interactions with CHIP-mutated monocytes. We used combined transcriptomic data derived from peripheral blood mononuclear cells of HF patients, both with and without CHIP, and cardiac tissue. We demonstrate that inactivation of DNMT3A in macrophages intensifies interactions with cardiac fibroblasts and increases cardiac fibrosis. DNMT3A inactivation amplifies the release of heparin-binding epidermal growth factor-like growth factor, thereby facilitating activation of cardiac fibroblasts. These findings identify a potential pathway of DNMT3A CHIP-driver mutations to the initiation and progression of HF and may also provide a compelling basis for the development of innovative anti-fibrotic strategies.
Assuntos
DNA Metiltransferase 3A , Insuficiência Cardíaca , Humanos , Hematopoiese Clonal , DNA (Citosina-5-)-Metiltransferases/genética , DNA Metiltransferase 3A/genética , Fibroblastos , Fibrose/genética , Fibrose/patologia , Insuficiência Cardíaca/genética , Hematopoese/genética , Leucócitos Mononucleares , Mutação , Cardiopatias/genética , Cardiopatias/patologiaRESUMO
The adult mammalian heart has limited regenerative capacity, while the neonatal heart fully regenerates during the first week of life. Postnatal regeneration is mainly driven by proliferation of preexisting cardiomyocytes and supported by proregenerative macrophages and angiogenesis. Although the process of regeneration has been well studied in the neonatal mouse, the molecular mechanisms that define the switch between regenerative and nonregenerative cardiomyocytes are not well understood. Here, using in vivo and in vitro approaches, we identified the lncRNA Malat1 as a key player in postnatal cardiac regeneration. Malat1 deletion prevented heart regeneration in mice after myocardial infarction on postnatal day 3 associated with a decline in cardiomyocyte proliferation and reparative angiogenesis. Interestingly, Malat1 deficiency increased cardiomyocyte binucleation even in the absence of cardiac injury. Cardiomyocyte-specific deletion of Malat1 was sufficient to block regeneration, supporting a critical role of Malat1 in regulating cardiomyocyte proliferation and binucleation, a landmark of mature nonregenerative cardiomyocytes. In vitro, Malat1 deficiency induced binucleation and the expression of a maturation gene program. Finally, the loss of hnRNP U, an interaction partner of Malat1, induced similar features in vitro, suggesting that Malat1 regulates cardiomyocyte proliferation and binucleation by hnRNP U to control the regenerative window in the heart.
Assuntos
Coração , Ribonucleoproteínas Nucleares Heterogêneas Grupo U , Infarto do Miocárdio , Miócitos Cardíacos , RNA Longo não Codificante , Regeneração , Animais , Camundongos , Coração/fisiologia , Coração/fisiopatologia , Traumatismos Cardíacos/genética , Traumatismos Cardíacos/metabolismo , Traumatismos Cardíacos/fisiopatologia , Ribonucleoproteínas Nucleares Heterogêneas Grupo U/genética , Ribonucleoproteínas Nucleares Heterogêneas Grupo U/metabolismo , Macrófagos/metabolismo , Macrófagos/fisiologia , Mamíferos , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/fisiologia , Neovascularização Fisiológica/genética , Neovascularização Fisiológica/fisiologia , Regeneração/genética , Regeneração/fisiologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismoRESUMO
AIMS: Coronavirus disease 2019 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has emerged as a global pandemic. SARS-CoV-2 infection can lead to elevated markers of cardiac injury associated with higher risk of mortality. It is unclear whether cardiac injury is caused by direct infection of cardiomyocytes or is mainly secondary to lung injury and inflammation. Here, we investigate whether cardiomyocytes are permissive for SARS-CoV-2 infection. METHODS AND RESULTS: Two strains of SARS-CoV-2 infected human induced pluripotent stem cell-derived cardiomyocytes as demonstrated by detection of intracellular double-stranded viral RNA and viral spike glycoprotein expression. Increasing concentrations of viral RNA are detected in supernatants of infected cardiomyocytes, which induced infections in Caco-2 cell lines, documenting productive infections. SARS-CoV-2 infection and induced cytotoxic and proapoptotic effects associated with it abolished cardiomyocyte beating. RNA sequencing confirmed a transcriptional response to viral infection as demonstrated by the up-regulation of genes associated with pathways related to viral response and interferon signalling, apoptosis, and reactive oxygen stress. SARS-CoV-2 infection and cardiotoxicity was confirmed in a 3D cardiosphere tissue model. Importantly, viral spike protein and viral particles were detected in living human heart slices after infection with SARS-CoV-2. Coronavirus particles were further observed in cardiomyocytes of a patient with coronavirus disease 2019. Infection of induced pluripotent stem cell-derived cardiomyocytes was dependent on cathepsins and angiotensin-converting enzyme 2, and was blocked by remdesivir. CONCLUSION: This study demonstrates that SARS-CoV-2 infects cardiomyocytes in vitro in an angiotensin-converting enzyme 2- and cathepsin-dependent manner. SARS-CoV-2 infection of cardiomyocytes is inhibited by the antiviral drug remdesivir.