Koh Young Jun, Kang Shinae, Lee Hyuek Jong, Choi Tae-Saeng, Lee Ho Sub, Cho Chung-Hyun, Koh Gou Young
National Research Laboratory of Vascular Biology and Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
J Clin Invest. 2007 Dec;117(12):3684-95. doi: 10.1172/JCI32504.
Little is known about whether bone marrow-derived circulating progenitor cells (BMDCPCs) can transdifferentiate into adipocytes in adipose tissues or play a role in expanding adipocyte number during adipose tissue growth. Using a mouse bone marrow transplantation model, we addressed whether BMDCPCs can transdifferentiate into adipocytes under standard conditions as well as in the settings of diet-induced obesity, rosiglitazone treatment, and exposure to G-CSF. We also addressed the possibility of transdifferentiation to adipocytes in a murine parabiosis model. In each of these settings, our findings indicated that BMDCPCs did not transdifferentiate into either unilocular or multilocular adipocytes in adipose tissues. Most BMDCPCs became resident and phagocytic macrophages in adipose tissues--which resembled transdifferentiated multilocular adipocytes by appearance, but displayed cell surface markers characteristic for macrophages - in the absence of adipocyte marker expression. When exposed to adipogenic medium in vitro, bone marrow cells differentiated into multilocular, but not unilocular, adipocytes, but transdifferentiation was not observed in vivo, even in the contexts of adipose tissue regrowth or dermal wound healing. Our results suggest that BMDCPCs do not transdifferentiate into adipocytes in vivo and play little, if any, role in expanding the number of adipocytes during the growth of adipose tissues.
关于骨髓来源的循环祖细胞（BMDCPCs）是否能在脂肪组织中转分化为脂肪细胞，或者在脂肪组织生长过程中在增加脂肪细胞数量方面发挥作用，目前所知甚少。我们利用小鼠骨髓移植模型，研究了在标准条件下以及饮食诱导肥胖、罗格列酮治疗和接触粒细胞集落刺激因子（G-CSF）的情况下，BMDCPCs是否能转分化为脂肪细胞。我们还研究了在小鼠联体共生模型中转分化为脂肪细胞的可能性。在上述每种情况下，我们的研究结果表明，BMDCPCs在脂肪组织中不会转分化为单泡或多泡脂肪细胞。大多数BMDCPCs在脂肪组织中成为驻留的吞噬性巨噬细胞——其外观类似于转分化的多泡脂肪细胞，但在不表达脂肪细胞标志物的情况下，显示出巨噬细胞特有的细胞表面标志物。当在体外暴露于成脂培养基时，骨髓细胞可分化为多泡脂肪细胞，而非单泡脂肪细胞，但即使在脂肪组织再生或皮肤伤口愈合的情况下，体内也未观察到转分化现象。我们的结果表明，BMDCPCs在体内不会转分化为脂肪细胞，并且在脂肪组织生长过程中，即使有作用，在增加脂肪细胞数量方面也发挥很小的作用。
