Project description:DNA methylation plays critical roles in regulating muscle cell fate determination and myogenesis. Tet dioxygenases are responsible for active DNA demethylation. The functions of Tet proteins in muscle regeneration have not been well characterized. Here we find that Tet2 is required for complete regeneration after muscle injury. Loss of Tet2 in myoblasts leads to reduced fusion index and thinner myofibers. Tet2 activates transcription of key differentiation modulator Myogenin (MyoG) further promoting myoblast differentiation and fusion. Re-expressing of MyoG in Tet2 KO myoblasts rescues the differentiation and fusion defects. Further mechanistic analysis reveals that Tet2 facilitates the recruitment of H3K4me1 and H3K27ac, increases the chromatin accessibility, and MyoD binding on MyoG enhancer. These functions are specifically executed by Tet2, but not Tet1 and Tet3. We identified the Tet2 specific function during myogenesis and shed new lights on DNA methylation and pioneer transcription factor transcription activation.
Project description:Tet dioxygenases are responsible for the active DNA demethylation. The functions of Tet proteins in muscle regeneration have not been well characterized. Here we find that Tet2, but not Tet1 and Tet3, is specifically required for muscle regeneration in vivo. Loss of Tet2 leads to severe muscle regeneration defects. Further analysis indicates that Tet2 regulates myoblast differentiation and fusion. Tet2 activates transcription of the key differentiation modulator Myogenin (MyoG) by actively demethylating its enhancer region. Re-expressing of MyoG in Tet2 KO myoblasts rescues the differentiation and fusion defects. Further mechanistic analysis reveals that Tet2 enhances MyoD binding by demethylating the flanking CpG sites of E boxes to facilitate the recruitment of active histone modifications and increase chromatin accessibility and activate its transcription. These findings shed new lights on DNA methylation and pioneer transcription factor activity regulation.
Project description:DNA methylation plays critical roles in regulating muscle cell fate determination and myogenesis. Tet dioxygenases are responsible for active DNA demethylation. The functions of Tet proteins in muscle regeneration have not been well characterized. Here we find that Tet2 is required for complete regeneration after muscle injury. Loss of Tet2 in myoblasts leads to reduced fusion index and thinner myofibers. Tet2 activates transcription of key differentiation modulator Myogenin (MyoG) further promoting myoblast differentiation and fusion. Re-expressing of MyoG in Tet2 KO myoblasts rescues the differentiation and fusion defects. Further mechanistic analysis reveals that Tet2 facilitates the recruitment of H3K4me1 and H3K27ac, increases the chromatin accessibility, and MyoD binding on MyoG enhancer. These functions are specifically executed by Tet2, but not Tet1 and Tet3. We identified the Tet2 specific function during myogenesis and shed new lights on DNA methylation and pioneer transcription factor transcription activation.
Project description:DNA methylation plays critical roles in regulating muscle cell fate determination and myogenesis. Tet dioxygenases are responsible for active DNA demethylation. The functions of Tet proteins in muscle regeneration have not been well characterized. Here we find that Tet2 is required for complete regeneration after muscle injury. Loss of Tet2 in myoblasts leads to reduced fusion index and thinner myofibers. Tet2 activates transcription of key differentiation modulator Myogenin (MyoG) further promoting myoblast differentiation and fusion. Re-expressing of MyoG in Tet2 KO myoblasts rescues the differentiation and fusion defects. Further mechanistic analysis reveals that Tet2 facilitates the recruitment of H3K4me1 and H3K27ac, increases the chromatin accessibility, and MyoD binding on MyoG enhancer. These functions are specifically executed by Tet2, but not Tet1 and Tet3. We identified the Tet2 specific function during myogenesis and shed new lights on DNA methylation and pioneer transcription factor transcription activation.
