BACKGROUNDIn our previous studies, we found that intraglomerular deposition of fibrin and its metabolites was related to glomerular sclerosis and reduced renal function. It has been reported that both overlying and underlying fibrin may induce specific morphological changes of cultured endothelial cells from large blood vessels. The dependency of these morphological changes on the integrin alphavbeta3-arginyl-glycyl-aspartyl-serine (RGDS) interaction is still controversial. We hypothesized that glomerular endothelial cells (GECs) stimulated by fibrin might undergo morphological changes through an integrin alphavbeta3-RGDS interaction. Methods. In vitro studies were performed to examine the growing status of GECs stimulated by overlying and underlying fibrin gels in the presence or absence of the following: 50 microg/ml anti-alphavbeta3 integrin monoclonal antibody 23C6 or nonimmune mouse IgG, 1 mg/ml synthetic RGDS or arginyl-glycyl-glycyl-serine (RGGS) peptide, 10 mg/ml sodium heparin, 100 microg/ml cycloheximide, and 10 microM actinomycin D. Fast protein liquid chromatography (FPLC)-purified fibrinogen and the third to fifth passages of human GECs were also used in this study.RESULTSGECs developed capillary tube structure after 60 hours of culturing on fibrin gels, and GECs cultured on gelatin-coated plates displayed a monolayer of cobblestone-like cells in the presence or absence of 23C6 and synthetic RGDS peptide. Fibrin-induced capillary tube formation was promoted by 23C6 and inhibited by RGDS peptide, cycloheximide, and actinomycin D. Disorganization of the GEC monolayer was induced by overlying fibrin, but was not induced by overlying agarose gels and glass cover slips or culturing in fibrinogen, 0.05 NIH U/ml thrombin, fibrin supernatants, as well as in fibrin degradation products. Disorganization of GEC monolayer can be induced by both des-AA-fibrin and des-AABB-fibrin and was unaffected by heparin. Furthermore, both 23C6 and synthetic RGDS peptide prevented disorganization of GECs induced by overlying fibrin, whereas nonimmune mouse IgG, synthetic RGGS peptide, cycloheximide, and actinomycin D had no similar effect.CONCLUSIONSGECs cultured on fibrin gels may develop capillary structure spontaneously, and GECs covered by fibrin gels may undergo disorganization. Our data suggest that these GEC morphological changes are mediated by an integrin alphavbeta3-RGDS interaction.

1995-11-01·Biochimica et Biophysica Acta (BBA) - Molecular Cell Research

The morphologic change of endothelial cells by ancrod-generated fibrin is triggered by αv β3 integrin binding and the subsequent activation of a G-protein coupled phospholipase C

Article

作者: Jiiang-Huei Jeng ; Tur-Fu Huang ; Tou-Chan Cheong ; Mei-Chi Chang

The mechanism of morphologic change of human cultured umbilical vein endothelial cells (HUVECs) caused by fibrin was investigated. Ancrod, a thrombin-like enzyme, did not cause morphologic alteration of HUVEC by itself at concentrations ranging from 0.01 to 10 U/ml. However, when 0.02 U/ml of ancrod was added to cultured HUVEC monolayers in the presence of citrated plasma, it caused pronounced morphologic change of HUVEC after 6-10 h incubation period. Gly-Pro-Arg-Pro (4 mg/ml), an inhibitor of fibrin polymerization, prevented the morphologic alteration, indicating that the morphologic alteration was caused by the polymerized fibrin. The morphologic change of HUVEC caused by ancrod-generated fibrin was not observed in the presence of an intracellular calcium mobilization inhibitor TMB-8 (50 microM), and the morphologic alteration was also less pronounced with BAPTA(15 microM)-loaded HUVECs and HUVECs pretreated with EGTA (1.2 mM). Ancrod (in Medium 199) itself did not stimulate phosphoinositide breakdown of HUVEC. However, when ancrod was present in plasma, it caused an increase of [3H]IP1 of HUVECs preloaded with [3H]myoinositol. This IP1 increment was inhibited by Gly-Pro-Arg-Pro. The increase of IP1 was significantly inhibited by the pretreatment of monoclonal antibodies 23C6 and 7E3 directed against alpha v beta 3 integrin. Neomycin (1 mM) and pertussis toxin (100 ng/ml), but not aspirin or mepacrine, blocked this enhanced phosphoinositide breakdown. The morphologic change was also prevented by the monoclonal antibodies, 23C6 and 7E3. These results suggest that both intra- and extra-cellular calcium participate in the event of morphologic change of HUVEC caused by ancrod-generated fibrin, and the morphologic change is mediated, at least in part, by fibrin binding to integrin alpha v beta 3 on HUVECs, causing the subsequent activation of the endogenous G-protein coupled phospholipase C.

1991-08-01·Experimental Cell Research3区 · 医学

ArgGlyAsp (RGD) peptides and the anti-vitronectin receptor antibody 23C6 inhibit dentine resorption and cell spreading by osteoclasts*1

3区 · 医学

Article

作者: M.L. Taylor ; M.H. Helfrich ; T.R. Arnett ; M.A. Horton

Studies with a range of monoclonal and polyclonal antisera to components of the human, rat, and chick vitronectin receptor, alpha V beta 3, and the VLA beta 1 chain show that chick and rat osteoclasts express similar integrin receptors to those described in man. Biochemical analysis with monoclonal antibody 23C6 confirmed the presence on chick osteoclasts of a vitronectin receptor heterodimer of similar size (110/95 kDa reduced) to that immunoprecipitated from human osteoclastoma giant cells. The synthetic peptide GRGDSP, corresponding to the cell adhesion sequence in fibronectin, but not GRGESP peptide, induced significant (P less than 0.005) osteoclast retraction in chick and rat osteoclasts at IC50s (+/- SEM) of 210.0 +/- 14.4 and 191.4 +/- 13.7 microM, respectively; monoclonal anti-vitronectin receptor alpha V beta 3 complex antibody, 23C6, produced similar changes in chick osteoclasts (IC50 = 1.45 +/- 0.22 microM). Antibody 23C6 inhibited the number of pits resorbed in dentine by chick osteoclasts over a concentration range of 4.4 to 88 micrograms/ml; a significant 76% reduction (P = 0.03) was observed at a final concentration of 88 micrograms/ml (6 microM). The effect of peptides upon dentine resorption was less dramatic. No consistent inhibition was seen using chick osteoclasts. Inhibitory effects on resorption by rat osteoclasts were, however, observed; significant reduction in resorption occurred with both GRGDSP (78%; P less than 0.01) and GRGESP (67%; P = 0.02) peptides at 400 microM peptide concentration. These data demonstrate that osteoclast function can be disrupted by low concentrations of the anti-vitronectin receptor antibody, 23C6. The inhibitory effects of the peptides used in this study produced effects on dentine resorption which were generally weaker and variable, although osteoclast cell adhesion was consistently inhibited in an Arg-Gly-Asp (RGD)-dependent manner. We conclude that the vitronectin receptor may play an important role in effecting resorption of mineralized tissues by osteoclasts.

100 项与 23C6(Harvard University) 相关的药物交易

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