Neurofibromin (Nf1) controls metabolic balance and Notch-dependent quiescence of murine juvenile myogenic progenitors [ChIP-seq]

We conclude that Nf1Myf5 MPs are driven towards quiescence and show metabolic reprogramming with severely inhibited glycolytic metabolism that, in turn impinges on H4K16ac decoration and expression of myogenic differentiation-related genes. ChIP-Seq analysis of freshly isolated p7 MPs showed apparently unaltered H3K4me3 levels between controls and Nf1Myf5 MPs, while H3K27me3 levels were globally reduced in Nf1Myf5 MPs. A reduction of H3K27me3 decoration was observed at genes associated with quiescence as Pax7, or with cell cycle repression as Cdkn2a. The assumption of a quiescent state in Nf1Myf5 MPs is concomitant to decreased repressive H3K27me3 modification at quiescence-associated genes. Overall design: Three histone modification marks (Histone 3 Lysine 4 trimethylation, Histone 3 Lysine27 trimethylation and Histone 4 Lysine16 acetylation) status were compared through ChIP-Seq analysis between freshly FACS sorted p7 controls and Nf1Myf5 MPs.

我们的研究表明：Nf1Myf5肌祖细胞（MPs）被诱导进入细胞静息态，并呈现代谢重编程特征，其糖酵解代谢受到显著抑制，进而干扰组蛋白4赖氨酸16乙酰化（H4K16ac）的修饰水平以及肌源性分化相关基因的表达。对新鲜分离的Pax7阳性肌祖细胞（p7 MPs）开展染色质免疫共沉淀测序（ChIP-Seq）分析后发现，对照组与Nf1Myf5肌祖细胞之间的组蛋白3赖氨酸4三甲基化（H3K4me3）水平无显著差异，而Nf1Myf5肌祖细胞的组蛋白3赖氨酸27三甲基化（H3K27me3）水平整体下调。在静息态相关基因（如Pax7）或细胞周期抑制相关基因（如Cdkn2a）的染色质位点上，均观测到H3K27me3修饰水平的下调。Nf1Myf5肌祖细胞呈现静息态的同时，其静息态相关基因上的抑制性H3K27me3修饰水平也同步降低。整体实验设计：通过染色质免疫共沉淀测序（ChIP-Seq）分析，对比新鲜经荧光激活细胞分选（FACS）分离的对照组Pax7阳性肌祖细胞与Nf1Myf5肌祖细胞之间三种组蛋白修饰标记（组蛋白3赖氨酸4三甲基化、组蛋白3赖氨酸27三甲基化及组蛋白4赖氨酸16乙酰化）的状态差异。