Differential effect of green tea catechins on three endothelial cell clones isolated from rat adipose tissue and on human umbilical vein endothelial cells.

By single colony isolation from the cells in stromal vascular fraction (SVF) dispersed from rat adipose tissues, we isolated three independent clones with different proliferation potential. All clones showed cobblestone-like morphology at the confluence and incorporated fluorescent Dil acetylated low density lipoprotein. When plated on Matrigel, they formed a capillary network-like structure. These rat adipose tissue endothelial cell (RATEC) clones showed higher expression of wnt2, wnt4, wnt5a, wnt5b, fzd1 and fzd5 whereas lower expression of cell cycle controlling genes such as CIP1, KIP1, KIP2, CDKN2A, CDKN2B, CDKN2C and CDKN2D compared to human umbilical vein endothelial cell (HUVEC). As reported for HUVEC, the growth of RATEC was inhibited by green tea catechins such as epigallocatechin, epicatechin gallate, epicatechin and epigallocatechin gallate but with higher sensitivity than HUVEC. The sensitivity of RATEC to catechins was higher for the cultures with low plating density and for the clone with higher proliferation potential.