Integrin beta4 mAb inhibited apoptosis induced by deprivation of growth factors in vascular endothelial cells.
OBJECTIVE
To understand the mechanism by which anti-beta4 integrin monoclonal antibody (mAb) inhibits apoptosis of vascular endothelial cells (VEC).


METHODS
Viability was determined by counting the cells that attached to dishes after treatments. DNA fragmentation was analyzed by agarose gel electrophoresis and fluorescence microscopy. The intracellular content of cAMP was measured by radioimmunoassay (RIA). The levels of p53 and Ras expressions were analyzed by fluorescence microscopy combined with immunofluorescence under laser scanning confocal microscopy.


RESULTS
After the cells were deprived of fibroblast growth factor (FGF) and serum were exposed to the mAb 5 mg/L for 24 h, the detachment and DNA fragmentation of these cells were suppressed. When cells were deprived of FGF and serum, the intracellular cAMP level and Ras protein content decreased (P<0.05), while the level of p53 protein expression increased (P<0.05). But in the presence of anti-beta4 integrin mAb, VEC apoptosis was inhibited, and at the same time, the changes mentioned above were obviously blocked (P<0.05).


CONCLUSIONS
Anti-4 integrin mAb inhibited apoptosis by affecting the level of cAMP, and blocking down-regulation of Ras protein and up-regulation of p53 protein in VEC.
Zhao
Ke-Wen
KW
Institute of Developmental Biology, School of Life Science, Shandong University, Ji-nan 250100, China. miaojy@sdu.edu.cn
Zhao
Qi-Tao
QT
Zhang
Shang-Li
SL
Miao
Jun-Ying
JY
D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000494:pharmacology*; D006801:Humans; D039663:Integrin beta4 / Q000276:immunology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014471:Umbilical Veins / Q000166:cytology; D018631:ras Proteins / Q000378:metabolism
D000911:Antibodies, Monoclonal; D039663:Integrin beta4; D016159:Tumor Suppressor Protein p53; D005346:Fibroblast Growth Factors; D000242:Cyclic AMP; D018631:ras Proteins