種々の間葉系細胞における脂肪細胞の分化誘導について

― ニワトリ血清因子の効果 ―

抄録

We have previously reported that chick serum (CKS) strongly induced adipogenesis in Meckel's chondrocyte in vitro, but little is known about the effects on other mesenchymal cells. In the present study, CKS-induced adipogenesis on the osteogenic MC3T3-E1 cells, mouse subcutaneous fibroblasts (MSF), and undifferentiated mouse dental pulp cells (MDP) were examined using light and electron microscopy, immunofluorescence staining, and BrdU-incorporation for DNA-synthesizing cells. Furthermore, MSF was cultured on a collagen-gel matrix that allowed maintenance of three-dimensional integrity. CKS facilitated lipogenesis and induced the formation of lipid droplets in all kinds of cells. Immunostaining showed the expression of peroxisome proliferator-activated receptor-γ in immature adipocytes, and leptin and glucose transporter-4 in mature adipocytes. Adipocytes on collagen-gel matrix induced unilocular lipid droplets at a high frequency. These morphological observations strongly indicate that these lipid-rich cells retain sufficient features as intact adipocytes, although the adipocytes that were formed in the present study were multilocular adipocytes. Furthermore, it was suggested that CKS agents involved in adipocyte differentiation are a common inductive factor affecting various mesenchymal cells.