Significant differential expression genes from HUVECs induced by bg-CAT

In vertebrates, non-lens bg-crystallins are widely expressed in various tissues, but their functions are unknown. The molecular mechanisms of trefoil factors, initiators of mucosal healing and being greatly involved in tumorigenesis, have remained elusive.A naturally existing 72-kDa complex of non-lens bg-crystallin (a-subunit) and trefoil factor (b-subunit), named bg-CAT, was identified from frog Bombina maxima skin secretions. Its a-subunit and b-subunit (containing three trefoil factor domains), with a non-covalently linked form of ab2, show significant sequence homology to ep37 proteins, a group of non-lens bg-crystallins identified in newt Cynops pyrrhogaster and mammalian trefoil factors, respectively. The bg-CAT showed multiple cellular effects on human umbilical vein endothelial cells. Low dosages of bg-CAT (25-50 pM) were able to stimulate cell migration and wound healing. At high concentrations, it induced cell detachment (EC50 10 nM) and apoptosis. The bg-CAT was rapidly endocytosed via intracellular vacuole formation. Under confocal microscope, some of the vacuoles were translocated to nucleus and partially fused with nuclear membrane. However, what exactly target of bg-CAT act on HUVECs nuclear is still unknown. Primary cultured HUVECs treated with bg-CAT (25 nM, 2 h) were selected for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain the genome wide level of significant differential gene expression induced by bg-CAT on HUVECs in order to get clues about bg-CAT action mechanisms. These findings illustrate novel cellular functions of non-lens bg-cyrstallins and action mechanism via association with trefoil factors, serving as clues for investigating the possible occurrence of similar molecules and action mechanisms in mammals.

8

Liu SB, He YY, Zhang Y, Lee WH, Qian JQ, Lai R, Jin Y