title: In vivo and in vitro cytotoxicity of brown spider venom for blood vessel endothelial cells.
abstract: The effect of brown spider (Loxosceles intermedia) venom on endothelial cells was investigated in vivo and in vitro. Morphological and ultrastructural observations by light microscopy and transmission electron microscopy showed that the venom acts in vivo upon vessel endothelial cells of rabbits that were intradermally injected, evoking vessel instability, cytoplasmic endothelial cell vacuolization, and blebs. Likewise, treatment of rabbit endothelial cells in culture with the venom led to loss of adhesion of the cells to the substrate. Endothelial cells in culture were metabolically radiolabeled with sodium [35S]-sulfate and the sulfated compounds (proteoglycans and sulfated proteins) from medium, cell surface, and extracellular matrix (ECM) were analyzed. Agarose gel electrophoresis and SDS-PAGE showed that the venom is active on the ECM and on cell surface proteoglycans, shedding these molecules into the culture medium. In addition, when purified heparan sulfate proteoglycan (HSPG) and purified laminin-entactin (LN/ET) complex were incubated with the venom we observed a partial degradation of the protein core of HSPG as well as the hydrolysis of entactin. The above results suggest that the L. intermedia venom has a deleterious effect on the endothelium of vessels both in vivo and in culture, removing important constituents such as HSPG and entactin that are involved in the adhesion of endothelial cells and of subendothelial ECM organization.
authors.affiliation: Department of Cell Biology, Federal University of Paraná, Jardim das Americas, 81531-990, Paraná, Curitiba, Brazil. veigass@bio.ufpr.br
authors.forename: S S
authors.initials: SS
authors.lastname: Veiga
authors.forename: V C
authors.initials: VC
authors.lastname: Zanetti
authors.forename: C R
authors.initials: CR
authors.lastname: Franco
authors.forename: E S
authors.initials: ES
authors.lastname: Trindade
authors.forename: M A
authors.initials: MA
authors.lastname: Porcionatto
authors.forename: O C
authors.initials: OC
authors.lastname: Mangili
authors.forename: W
authors.initials: W
authors.lastname: Gremski
authors.forename: C P
authors.initials: CP
authors.lastname: Dietrich
authors.forename: H B
authors.initials: HB
authors.lastname: Nader
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000737:chemistry; D002460:Cell Line; D002478:Cells, Cultured; D003603:Cytotoxins / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000378:metabolism; D008854:Microscopy, Electron; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology*; D011817:Rabbits; D013111:Spider Venoms / Q000494:pharmacology*
chemical_list: D003603:Cytotoxins; D019812:Heparan Sulfate Proteoglycans; D008562:Membrane Glycoproteins; D013111:Spider Venoms; C055161:loxosceles venom; C029967:nidogen; D010727:Phosphoric Diester Hydrolases