2012 Fiscal Year Final Research Report

Can brown adipocytes proliferate?

Research Project

Project/Area Number	23659027
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Biological pharmacy
Research Institution	Hokkaido University
Principal Investigator	KAJIMOTO Kazuaki 北海道大学, 大学院・薬学研究院, 特任准教授 (10416216)
Project Period (FY)	2011 – 2012
Keywords	細胞・組織 / 遺伝子 / マイクロアレイ / 褐色脂肪細胞
Research Abstract	In this study, we have established the methodology for live brown adipose tissue (BAT)imagingof a tissue slice prepared by a microslicer using a confocal laser scanning microscopy. In addition,we have succeeded the slice culture of brown adipose tissue using a membrane filter for organculture. This methodology was also applicable for the live tissue imaging of white adipose tissue(WAT). By this observation method, we attempted to find the proliferation of mature brownadipocytes in BAT, however, we failed to find it under the various culture conditions. Thus, wenext analyzed the gene expression profiles in primary cultured brown preadipocytes and maturebrown adipocytes using a maicroarray. As a result, numerous genes involved in the regulation ofcell cycle and proliferation were down-regulated in mature brown adipocytes, compared topreadipocytes. These findings strongly suggest that hypertrophy ofBAT induced by cold exposureis mainly resulted from the proliferation of preadipocytes and differentiation of them into maturebrown adipocytes