细胞形状决定干细胞分化.ppt

L/O/G/O 细胞形状决定干细胞分化 陈应炉 干细胞的一个重要特性—多向分化潜能 为何分化出的细胞形状千差万别 细胞骨架是维持细胞形状的基础 是细胞形状决定了干细胞分化 OR 干细胞分化影响了细胞形状 ？ ？ 细胞骨架决定了干细胞分化 Geometric cues for directing the differentiation of mesenchymal stem cells PNAS 2009 adipogenesis osteogenesis A B (A)-(C) Immunofluorescent images of cells in flower and star shapes stained for F-actin (green), vinculin (red) and nuclei (blue). (D) Immunoflourescent images of cells in flower and star shapes stained for myosin IIa. (E) Fluorescent heatmaps of 80 cells stained for myosin IIa as a quantitative measure of contractility. A B C D E Min Max myosin IIa, the primary motor protein nocodazole,a potent microtubule depolymerizing agent， increase cell contractility Cytochalasin D is a small molecule that inhibits F-actin polymerization ①blebbistatin, which inhibits myosin II ②Y-27632,which inhibits ROCK， directly inhibit contractility α5β1 integrin blocking antibodies Inhibition of MAPK and Wnt Signaling in Patterned Cells (C) Change in differentiation from control when exposed to MAPK inhibitors . (D) Change in differentiation of cells in the presence of Wnt antagonists. (E) Speculative pathway for shape directed differentiation of adherent MSCs. hMSC commitment Depends on Cell Density (A–D) Brightfield images of hMSCs plated at 1000 cells/cm2 (A and B) or 25,000 cells/cm2(C and D), cultured for 4 weeks in adipogenic(A and C) or 3 weeks in osteogenic (B andD) differentiation media, and stained for the presence of lipids (A and C) or alkaline phosphatase (B and D). (E and F) Plot of hMSC percentage differentiation over time when cultured at 1000, 3000,21,000, or 25,000 cells/cm2 in the presence of adipogenic differentiation media (E) or osteogenic differentiation media (F). (G and H) Plot of hMSC relative density over time when plated at the different seeding densities in the presence of adipogenic (G) or osteogenic (H) differentiation media.