Suenaga Masashi, Matsui Tohru, Funaba Masayuki
Division of Applied Biosciences, Kyoto University Graduate School of Agriculture, Kitashirakawa Oiwakecho, Kyoto 606-8502, Japan.
J Vet Med Sci. 2010 Mar;72(3):373-7. doi: 10.1292/jvms.09-0442. Epub 2009 Dec 8.
Previous studies revealed that bone morphogenetic protein (BMP) induces commitment to the adipocyte lineage in pluripotent stem cells. The present study explored the role of endogenous BMP activity in 3T3-L1 preadipocytes. The expression of phospho-Smad1/5/8 was monitored because BMP transmits its signal through Smad1/5/8 phosphorylation. Phosphorylated Smad1/5/8 was higher in proliferating preadipocytes, and lower in differentiating adipocytes after removing differentiation inducers. Reporter assays revealed that dorsomorphin predominantly inhibits the BMP pathway but not the structurally related TGF-beta/activin pathway. The addition of dorsomorphin to the culture medium prior to treatment with differentiation inducers impaired lipid accumulation in 3T3-L1 cells. The present study indicated that activation of BMP signaling in preadipocytes is required for these cells to initiate the adipogenic program.
先前的研究表明，骨形态发生蛋白（BMP）可诱导多能干细胞向脂肪细胞谱系分化。本研究探讨了内源性BMP活性在3T3-L1前脂肪细胞中的作用。由于BMP通过Smad1/5/8磷酸化传递信号，因此监测了磷酸化Smad1/5/8的表达。增殖期前脂肪细胞中磷酸化Smad1/5/8水平较高，去除分化诱导剂后，分化期脂肪细胞中该水平较低。报告基因检测显示， dorsomorphin主要抑制BMP信号通路，而不抑制结构相关的TGF-β/激活素信号通路。在用分化诱导剂处理之前，向培养基中添加dorsomorphin会损害3T3-L1细胞中的脂质积累。本研究表明，前脂肪细胞中BMP信号的激活是这些细胞启动脂肪生成程序所必需的。
