Cell Biological Study of Fat Cells of the Obese : Elucidation of Mechanism of the Cellular Proliferation.

成熟的白色脂肪细胞（单眼脂肪细胞）通常被认为处于终末分化，因此没有增殖能力。我的实验室发明了一种被称为“天花板培养”的新方法。此外，我们建立了三维胶原凝胶培养，并进一步在体外重建皮肤组织，包括皮下脂肪组织。在这种培养条件下，单眼脂肪细胞继续表现出特定的脂质代谢功能，并广泛增殖。这种增殖能力在从前脂肪细胞分化出来的单眼脂肪细胞中也观察到。近年来，不仅在肿瘤细胞中检测到癌基因产物，而且在发育细胞中也检测到癌基因产物。因此，我们在体内脂肪组织和体外脂肪细胞中观察了ras、myc和neu （erbB-2）癌基因产物。neu的致癌基因产物在新生大鼠的发育性脂肪细胞中特异性检测到，特别是在增殖阶段的培养脂肪细胞中。我们将把这项研究推广到人类肥胖。

Mature white fat cells (unilocular fat cells) have generally been considered to be in terminal differentiation, and hence, to have no proliferative ability. A new method, referred to as "ceiling culture" has been devised in my laboratory. In addition, we established three-dimensional collagen gel culture, and furthermore reconstructed the skin tissue including subcutaneous fatty tissue in vitro. Under such culture conditions, the unilocular fat cells continue to exhibit specific functions of lipid metabolism and proliferate extensively. This proliferative ability was observed also in unilocular fat cells which differentiated from preadipocytes.Recently, oncogene products were detected not only in neoplastic cells but also in developmental cells. So, we observed immunohistochemically ras, myc and neu (erbB-2) oncogene products in the fat tissue in vivo and the fat cells in vitro. Oncogene products of neu was specifically detected in the developmental fatty cells of newborn rats and parcially in the cultured fat cells in the proliferative stage. We will promote this study to the human obesity.