Project description:DNA methylation is an essential epigenetic regulation for cellular identity. In muscle stem cells, termed satellite cells, DNA methylation patterns are dynamically changed during muscle regeneration. However, how these DNA methylation patterns are maintained remain unclear. Here, we demonstrate that a key epigenetic regulator Uhrf1 (ubiquitin-like with PHD and RING finger domains 1) is activated in proliferating but not expressed in quiescent or differentiated satellite cells. Ablation of Uhrf1 in satellite cell impairs the proliferation and differentiation of satellite cells, leading to failure of muscle regeneration. Loss of Uhrf1 in satellite cells alters transcriptional programs and leads to DNA hypomethylation with the activation of Cdkn1a and Notch signalling. Down-regulation of Cdkn1a and Notch signalling rescued the proliferation and differentiation defect in Uhrf1-deficient satellite cells. Therefore, this study suggest that Uhrf1 can regulate the self-renewal and differentiation of satellite cells through DNA methylation patterning.
Project description:DNA methylation is an essential epigenetic regulation for cellular identity. In muscle stem cells, termed satellite cells, DNA methylation patterns are dynamically changed during muscle regeneration. However, how these DNA methylation patterns are maintained remain unclear. Here, we demonstrate that a key epigenetic regulator Uhrf1 (ubiquitin-like with PHD and RING finger domains 1) is activated in proliferating but not expressed in quiescent or differentiated satellite cells. Ablation of Uhrf1 in satellite cell impairs the proliferation and differentiation of satellite cells, leading to failure of muscle regeneration. Loss of Uhrf1 in satellite cells alters transcriptional programs and leads to DNA hypomethylation with the activation of Cdkn1a and Notch signalling. Down-regulation of Cdkn1a and Notch signalling rescued the proliferation and differentiation defect in Uhrf1-deficient satellite cells. Therefore, this study suggest that Uhrf1 can regulate the self-renewal and differentiation of satellite cells through DNA methylation patterning.
Project description:DNA methylation is an essential form of epigenetic regulation responsible for cellular identity. In muscle stem cells, termed satellite cells, DNA methylation patterns are tightly regulated during differentiation. However, it is unclear how these DNA methylation patterns affect the function of satellite cells. We demonstrate that a key epigenetic regulator, ubiquitin like with PHD and RING finger domains 1 (Uhrf1), is activated in proliferating myogenic cells but not expressed in quiescent satellite cells or differentiated myogenic cells in mice. Ablation of Uhrf1 in mouse satellite cells impairs their proliferation and differentiation, leading to failed muscle regeneration. Uhrf1-deficient myogenic cells exhibited aberrant up-regulation of transcripts, including Sox9, with the reduction of DNA methylation level of their promoter and enhancer region. These findings show that Uhrf1 is a critical epigenetic regulator of proliferation and differentiation in satellite cells, by controlling cell type-specific gene expression via maintenance of DNA methylation.
Project description:Following skeletal muscle injury, muscle stem cells (satellite cells) are activated, proliferate, and differentiate to form myofibers. We show that mRNA decay protein AUF1 regulates satellite cell function through targeted degradation of specific mRNAs. AUF1 targets certain mRNAs containing 3 AU-rich elements (AREs) for rapid decay. Auf1-/- (KO) mice undergo accelerated skeletal muscle wasting with age and impaired muscle repair following injury. Satellite cell mRNA analysis and regeneration studies demonstrate that auf1-/- satellite cell self-renewal is impaired due to increased stability and overexpression of ARE-mRNAs. Control of ARE-mRNA decay by AUF1 and potentially other ARE-binding proteins represents a mechanism for adult stem cell regulation and is implicated in human muscle wasting diseases. We report the RNA transcript expression profiles from sorted satellite cells isolated from wild type (WT) and AUF1-null (KO) mice hindlimb muscles Examination of RNA transcript expression from satellite cells of two genotypes Please note that mice are bred through a C57BL/6 strain of 129 background.
