RESUMO
The function of a cell is defined by its intrinsic characteristics and its niche: the tissue microenvironment in which it dwells. Here we combine single-cell and spatial transcriptomics data to discover cellular niches within eight regions of the human heart. We map cells to microanatomical locations and integrate knowledge-based and unsupervised structural annotations. We also profile the cells of the human cardiac conduction system1. The results revealed their distinctive repertoire of ion channels, G-protein-coupled receptors (GPCRs) and regulatory networks, and implicated FOXP2 in the pacemaker phenotype. We show that the sinoatrial node is compartmentalized, with a core of pacemaker cells, fibroblasts and glial cells supporting glutamatergic signalling. Using a custom CellPhoneDB.org module, we identify trans-synaptic pacemaker cell interactions with glia. We introduce a druggable target prediction tool, drug2cell, which leverages single-cell profiles and drug-target interactions to provide mechanistic insights into the chronotropic effects of drugs, including GLP-1 analogues. In the epicardium, we show enrichment of both IgG+ and IgA+ plasma cells forming immune niches that may contribute to infection defence. Overall, we provide new clarity to cardiac electro-anatomy and immunology, and our suite of computational approaches can be applied to other tissues and organs.
Assuntos
Microambiente Celular , Coração , Multiômica , Miocárdio , Humanos , Comunicação Celular , Fibroblastos/citologia , Ácido Glutâmico/metabolismo , Coração/anatomia & histologia , Coração/inervação , Canais Iônicos/metabolismo , Miocárdio/citologia , Miocárdio/imunologia , Miocárdio/metabolismo , Miócitos Cardíacos/citologia , Neuroglia/citologia , Pericárdio/citologia , Pericárdio/imunologia , Plasmócitos/imunologia , Receptores Acoplados a Proteínas G/metabolismo , Nó Sinoatrial/anatomia & histologia , Nó Sinoatrial/citologia , Nó Sinoatrial/fisiologia , Sistema de Condução Cardíaco/anatomia & histologia , Sistema de Condução Cardíaco/citologia , Sistema de Condução Cardíaco/metabolismoRESUMO
PAX7 transcription factor plays a crucial role in embryonic myogenesis and in adult muscles in which it secures proper function of satellite cells, including regulation of their self renewal. PAX7 downregulation is necessary for the myogenic differentiation of satellite cells induced after muscle damage, what is prerequisite step for regeneration. Using differentiating pluripotent stem cells we documented that the absence of functional PAX7 facilitates proliferation. Such action is executed by the modulation of the expression of two proteins involved in the DNA methylation, i.e., Dnmt3b and Apobec2. Increase in Dnmt3b expression led to the downregulation of the CDK inhibitors and facilitated cell cycle progression. Changes in Apobec2 expression, on the other hand, differently impacted proliferation/differentiation balance, depending on the experimental model used.
Assuntos
Desaminases APOBEC/metabolismo , DNA (Citosina-5-)-Metiltransferases/metabolismo , Proteínas Musculares/metabolismo , Fator de Transcrição PAX7/metabolismo , Desaminases APOBEC/genética , Animais , Ciclo Celular/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular/genética , Proliferação de Células/genética , Células Cultivadas , DNA (Citosina-5-)-Metiltransferases/genética , Metilação de DNA , Feminino , Expressão Gênica/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Desenvolvimento Muscular/genética , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/fisiologia , Células-Tronco Pluripotentes/metabolismo , Células-Tronco Pluripotentes/fisiologia , Células Satélites de Músculo Esquelético/metabolismo , DNA Metiltransferase 3BRESUMO
In case of large injuries of skeletal muscles the pool of endogenous stem cells, i.e., satellite cells, might be not sufficient to secure proper regeneration. Such failure in reconstruction is often associated with loss of muscle mass and excessive formation of connective tissue. Therapies aiming to improve skeletal muscle regeneration and prevent fibrosis may rely on the transplantation of different types of stem cell. Among such cells are adipose tissue-derived stromal cells (ADSCs) which are relatively easy to isolate, culture, and manipulate. Our study aimed to verify applicability of ADSCs in the therapies of severely injured skeletal muscles. We tested whether 3D structures obtained from Matrigel populated with ADSCs and transplanted to regenerating mouse gastrocnemius muscles could improve the regeneration. In addition, ADSCs used in this study were pretreated with myoblasts-conditioned medium or anti-TGFß antibody, i.e., the factors modifying their ability to proliferate, migrate, or differentiate. Analyses performed one week after injury allowed us to show the impact of 3D cultured control and pretreated ADSCs at muscle mass and structure, as well as fibrosis development immune response of the injured muscle.
