Soluble egg antigens from Schistosoma mansoni induce angiogenesis-related processes by up-regulating vascular endothelial growth factor in human endothelial cells.
Schistosomiasis mansoni is characterized by hepatic granuloma formation. Endothelial cell activation within these granulomas may contribute to their development and to increased vascularization in the granuloma periphery. The earliest event in granuloma formation is the lodging of schistosome eggs within presinusoidal capillaries. The eggs secrete factors that may activate endothelial cells. This study investigated the effects of Schistosoma mansoni soluble egg antigen (SEA) on angiogenic processes: proliferation, tube formation, and apoptosis of human umbilical vein endothelial cells (HUVECs). HUVECs require serum and growth factors to proliferate in vitro. Proliferation occurred when SEA or live eggs were substituted for growth factors, but not for serum. SEA increased HUVEC tube formation and decreased HUVEC apoptosis after serum and growth factor deprivation. Messenger RNA for vascular endothelial growth factor (VEGF) increased 2-fold in SEA-treated HUVECs. These findings suggest that products secreted by schistosome eggs may promote angiogenesis within hepatic granulomas by up-regulating endothelial cell VEGF.
Loeffler
David A
DA
Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, Michigan, USA. aa2690@hotmail.com
Lundy
Steven K
SK
Singh
Kameshwar P
KP
Gerard
Herve C
HC
Hudson
Alan P
AP
Boros
Dov L
DL
D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D016228:Endothelial Growth Factors / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D006801:Humans; D008222:Lymphokines / Q000378:metabolism*; D009389:Neovascularization, Pathologic; D010063:Ovum / Q000276:immunology*; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000150:complications; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D000947:Antigens, Helminth; D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors