Epigenetic modifiers are necessary but not sufficient for reprogramming non-myelinating cells into myelin gene-expressing cells.
Epigenetic modifiers are necessary but not sufficient for reprogramming non-myelinating cells into myelin gene-expressing cells.
复制标题
DOI：
10.1371/journal.pone.0013023
复制
发表时间：
2010-09-27
期刊：
影响因子：
3.7
通讯作者：
Casaccia P
中科院分区：
文献类型：
--
作者：
Liu J;Sandoval J;Doh ST;Cai L;López-Rodas G;Casaccia P
特定组蛋白残基的修饰和DNA甲基化在谱系选择和细胞重编程中起重要作用。我们之前已经表明，组蛋白修饰或转录因子的组合编码（tf）对于多潜能祖细胞向髓鞘少突胶质细胞的分化至关重要。在这项研究中，我们询问是否将DNA甲基化和组蛋白乙酰化的整体操作与少突胶质细胞特异性tf的表达结合起来，足以将成纤维细胞的身份转换为髓鞘基因表达细胞。将6个少突胶质细胞特异性tf （Olig1、Olig2、Sox10、Mash1、E47和Nkx2.2）转染到NIH3T3成纤维细胞中，能够诱导髓磷脂基因启动子驱动的报告基因的表达，但不激活内源性髓磷脂基因的表达。这些结果表明NIH3T3成纤维细胞中存在转录功能不全的染色质构象。利用染色质免疫沉淀（ChIP）分析，我们比较了髓磷脂基因保守区域（即Mbp和Mag）的组蛋白编码在分化少突胶质细胞祖细胞和NIH3T3成纤维细胞中的差异。髓磷脂基因位点的染色质特征是NIH3T3成纤维细胞中存在抑制性组蛋白修饰（me3K9H3和me3K27H3），而少突胶质细胞谱系细胞中存在活性组蛋白标记（me3K4H3和AcH3）。为了诱导具有转录能力的染色质特征，NIH3T3成纤维细胞用5-azadeoxy-citidine （5-AzaC）处理以降低DNA甲基化，用trichostatin a （TSA）或sirtinol处理以促进组蛋白乙酰化。用5-AzaC/TSA而不是sirtinol处理，可以在成纤维细胞中检测到内源性髓鞘基因转录物，尽管没有达到在髓鞘细胞中检测到的水平。5-AzaC/TSA处理后转染少突胶质细胞特异性tf不会进一步增加髓鞘基因表达，也不会将NIH3T3成纤维细胞的转录网络重编程为少突胶质细胞的转录网络。这些结果表明，将成纤维细胞重编程为表达髓磷脂基因的细胞不仅需要转录激活，还需要染色质操作，而不仅仅是组蛋白乙酰化和DNA甲基化。
Modifications on specific histone residues and DNA methylation play an essential role in lineage choice and cellular reprogramming. We have previously shown that histone modifications or combinatorial codes of transcription factors (TFs) are critical for the differentiation of multipotential progenitors into myelinating oligodendrocytes. In this study we asked whether combining global manipulation of DNA methylation and histone acetylation together with the expression of oligodendrocyte- specific TFs, was sufficient to switch the identity of fibroblasts into myelin gene-expressing cells. Transfection of six oligodendrocyte-specific TFs (Olig1, Olig2, Sox10, Mash1, E47 and Nkx2.2) into NIH3T3 fibroblasts was capable of inducing expression of myelin gene promoter-driven reporters, but did not activate endogenous myelin gene expression. These results suggested the existence of a transcriptionally incompetent chromatin conformation in NIH3T3 fibroblasts. Using chromatin immunoprecipitation (ChIP) analysis, we compared the histone code on the conserved regions of myelin genes (i.e. Mbp and Mag) in differentiating oligodendrocyte progenitors and NIH3T3 fibroblasts. Chromatin at myelin gene loci was characterized by the presence of repressive histone modifications (me3K9H3 and me3K27H3) in NIH3T3 fibroblasts and active histone marks (me3K4H3 and AcH3) in oligodendrocyte lineage cells. To induce a transcriptionally competent chromatin signature, NIH3T3 fibroblasts were treated with 5-azadeoxy-citidine (5-AzaC) to decrease DNA methylation, and trichostatin A (TSA) or sirtinol, to favor histone acetylation. Treatment with 5-AzaC/TSA but not sirtinol, resulted in the detection of endogenous myelin gene transcripts in fibroblasts, although not to the levels detected in myelinating cells. Transfection of oligodendrocyte-specific TFs after 5-AzaC/TSA treatment did not further increase myelin gene expression, nor did it reprogram the transcriptional network of NIH3T3 fibroblasts into that of oligodendrocytes. These results suggest that reprogramming of fibroblasts into myelin gene-expressing cells not only requires transcriptional activation, but also chromatin manipulations that go beyond histone acetylation and DNA methylation.
登录
查看更多内容
影响因子：
5.2
作者：
Ruau, David;Ensenat-Waser, Roberto;Zenke, Martin
通讯作者：
Zenke, Martin
影响因子：
23.9
作者：
Shi, Yan;Desponts, Caroline;Ding, Sheng
通讯作者：
Ding, Sheng
影响因子：
64.5
作者：
Takahashi, Kazutoshi;Yamanaka, Shinya
通讯作者：
Yamanaka, Shinya
影响因子：
64.5
作者：
Emery B;Agalliu D;Cahoy JD;Watkins TA;Dugas JC;Mulinyawe SB;Ibrahim A;Ligon KL;Rowitch DH;Barres BA
通讯作者：
Barres BA
影响因子：
46.9
作者：
Danwei Huangfu;Osafune, Kenji;Melton, Douglas A.
通讯作者：
Melton, Douglas A.