title: Autocrine FGF-2 is responsible for the cell density-dependent susceptibility to apoptosis of HUVEC : A role of a calpain inhibitor-sensitive mechanism.
abstract: To elucidate the factors affecting endothelial susceptibility to apoptosis, we studied the effects of cell density on endothelial cell apoptosis induced by deprivation of serum and fibroblast growth factor-2 (FGF-2/basic FGF). On deprivation, more cells became apoptotic in a dense culture (5 x 10(2) cells/mm(2)) than in a sparse culture (1 x 10(2) cells/mm(2)) of human umbilical vein endothelial cells. FGF-2, hepatocyte growth factor, and vascular endothelial cell growth factor, but not insulin-like growth factor-I, decreased apoptosis in the dense culture to a level similar in the sparse culture. An anti-FGF-2 antibody significantly increased the apoptosis in the sparse culture, suggesting that the sparse culture was resistant to apoptosis because of the greater autocrine production of FGF-2. Western blot analysis and metabolic labeling revealed that the sparse culture has, in fact, more FGF-2 than the dense culture. The steady state level of mRNA for FGF-2 was not significantly different between the dense and sparse cultures. Among a panel of inhibitors for 2 major cytoplasmic proteolytic enzymes, calpain inhibitors increased FGF-2 in the dense culture, but proteasome inhibitors did not. Our findings demonstrate that cell density affects endothelial survival by regulating autocrine FGF-2 production through a calpain inhibitor-sensitive mechanism.
authors.affiliation: National Cardiovascular Center Research Institute, Fujishirodai 5-7-1, Suita, Osaka 565-8565, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kinoshita
authors.forename: K
authors.initials: K
authors.lastname: Shimokado
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D019898:Autocrine Communication / Q000187:drug effects / Q000502:physiology; D002154:Calpain / Q000037:antagonists & inhibitors*; D002452:Cell Count; D002478:Cells, Cultured; D003593:Cytoplasm / Q000201:enzymology; D016228:Endothelial Growth Factors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000737:chemistry / Q000166:cytology* / Q000201:enzymology; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic; D017228:Hepatocyte Growth Factor / Q000494:pharmacology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D008222:Lymphokines / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface / Q000502:physiology; D017468:Receptors, Fibroblast Growth Factor / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D014471:Umbilical Veins / Q000166:cytology; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D016228:Endothelial Growth Factors; D008222:Lymphokines; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2; D017228:Hepatocyte Growth Factor; D007334:Insulin-Like Growth Factor I; D002154:Calpain