Wagh V, Doss M X, Sabour D, Niemann R, Meganathan K, Jagtap S, Gaspar J A, Ardestani M A, Papadopoulos S, Gajewski M, Winkler J, Hescheler J, Sachinidis A
Center of Physiology and Pathophysiology, Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, Cologne 50931, Germany.
Center of Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Robert-Koch-Str. 39, Cologne 50931, Germany.
Cell Death Dis. 2014 Jul 10;5(7):e1320. doi: 10.1038/cddis.2014.273.
FAM40B (STRIP2) is a member of the striatin-interacting phosphatase and kinase (STRIPAK) complex that is involved in the regulation of various processes such as cell proliferation and differentiation. Its role for differentiation processes in embryonic stem cells (ESCs) is till now completely unknown. Short hairpin RNA (shRNA)-mediated silencing of Fam40b expression in ESCs and differentiating embryoid bodies (EBs) led to perturbed differentiation to embryonic germ layers and their derivatives including a complete abrogation of cardiomyogenesis. Pluripotency factors such as Nanog, Oct4 and Sox2 as well as epigenetic factors such as histone acetyltransferase type B (HAT1) and DNA (cytosine-5)-methyltransferase 3-β (Dnmt3b) were highly upregulated in Fam40b knockdown EBs as compared with control and scrambled EBs. To examine the relevance of Fam40b for development in vivo, Fam40b was knocked down in developing zebrafish. Morpholino-mediated knockdown of Fam40b led to severe abnormalities of the cardiovascular system, including an impaired expression of ventricular myosin heavy chain (vmhc) and of cardiac myosin light chain 2 (cmlc2) in the heart. We identified the gene product of Fam40b in ESCs as a perinuclear and nucleolar protein with a molecular weight of 96 kDa. We conclude that the expression of Fam40b is essential for the lineage commitment of murine embryonic stem cells (mESCs) into differentiated somatic cells via mechanisms involving pluripotency and epigenetic networks.
FAM40B（STRIP2）是striatin相互作用磷酸酶和激酶（STRIPAK）复合体的成员，该复合体参与细胞增殖和分化等多种过程的调控。其在胚胎干细胞（ESC）分化过程中的作用至今完全未知。短发夹RNA（shRNA）介导的ESC和分化的胚状体（EB）中Fam40b表达沉默导致向胚胎胚层及其衍生物的分化受到干扰，包括心肌发生完全缺失。与对照和乱序EB相比，多能性因子如Nanog、Oct4和Sox2以及表观遗传因子如B型组蛋白乙酰转移酶（HAT1）和DNA（胞嘧啶-5）-甲基转移酶3-β（Dnmt3b）在Fam40b敲低的EB中高度上调。为了研究Fam40b在体内发育中的相关性，在发育中的斑马鱼中敲低Fam40b。吗啉代介导的Fam40b敲低导致心血管系统严重异常，包括心脏中心室肌球蛋白重链（vmhc）和心肌肌球蛋白轻链2（cmlc2）表达受损。我们在ESC中鉴定出Fam40b的基因产物是一种分子量为96 kDa的核周和核仁蛋白。我们得出结论，Fam40b的表达对于小鼠胚胎干细胞（mESC）通过涉及多能性和表观遗传网络的机制向分化的体细胞进行谱系定向分化至关重要。
