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阶段，因此没有增殖能力。在我的实验室里，一种被称为“天花板培养”的新方法被设计出来。此外，我们还建立了三维胶原凝胶培养体系，并在体外构建了包括皮下脂肪组织在内的皮肤组织。在这样的培养条件下，单眼脂肪细胞继续表现出特定的脂代谢功能，并广泛增殖。从前脂肪细胞分化而来的单眼脂肪细胞也有这种增殖能力。最近，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了癌基因产物。因此，我们用免疫组织化学方法观察了体内脂肪组织和体外培养的脂肪细胞中ras、myc和neu(erbB-2)癌基因产物。Neu癌基因产物在新生大鼠的发育脂肪细胞中特异表达，尤其在增殖期培养的脂肪细胞中检测到。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.