6533b828fe1ef96bd1287aac
RESEARCH PRODUCT
Rho protein inactivation induced apoptosis of cultured human endothelial cells.
P. D. N'guessanJoachim SeyboldChristoph Von Eichel-streiberMatthias KrüllStefan HippenstielNorbert SuttorpKlaus T. PreissnerBernd Schmecksubject
Pulmonary and Respiratory Medicinerac1 GTP-Binding Proteinrho GTP-Binding ProteinsProgrammed cell deathUmbilical VeinsEndotheliumPhysiologyBacterial ToxinsCASP8 and FADD-Like Apoptosis Regulating ProteinApoptosisBcl-2-associated X proteinBacterial ProteinsPhysiology (medical)Proto-Oncogene ProteinsmedicineCyclic AMPIn Situ Nick-End LabelingHumanscdc42 GTP-Binding ProteinCells Culturedbcl-2-Associated X ProteinAdenosine Diphosphate RibosebiologyCaspase 3Intracellular Signaling Peptides and ProteinsCell BiologyCaspase 9Cell biologyNeoplasm ProteinsEndothelial stem cellmedicine.anatomical_structureCdc42 GTP-Binding ProteinProto-Oncogene Proteins c-bcl-2Cell cultureApoptosisCaspasesbiology.proteinMyeloid Cell Leukemia Sequence 1 ProteinEndothelium VascularSignal transductionCarrier ProteinsrhoA GTP-Binding ProteinBH3 Interacting Domain Death Agonist ProteinSignal Transductiondescription
Small GTP-binding Rho GTPases regulate important signaling pathways in endothelial cells, but little is known about their role in endothelial cell apoptosis. Clostridial cytotoxins specifically inactivate GTPases by glucosylation [ Clostridium difficile toxin B-10463 (TcdB-10463), C. difficile toxin B-1470 (TcdB-1470)] or ADP ribosylation ( C. botulinum C3 toxin). Exposure of human umbilical cord vein endothelial cells (HUVEC) to TcdB-10463, which inhibits RhoA/Rac1/Cdc42, or to C3 toxin, which inhibits RhoA, -B, -C, resulted in apoptosis, whereas inactivation of Rac1/Cdc42 with TcdB-1470 was without effect, suggesting that Rho inhibition was responsible for endothelial apoptosis. Disruption of endothelial microfilaments as well as inhibition of p160ROCK did not induce endothelial apoptosis. Exposure to TcdB-10463 resulted in activation of caspase-9 and -3 but not caspase-8 in HUVEC. Moreover, Rho inhibition reduced expression of antiapoptotic Bcl-2 and Mcl-1 and increased proapoptotic Bid but had no effect on Bax or FLIP protein levels. Caspase-3 activity and apoptosis induced by TcdB-10463 were abolished by cAMP elevation. In summary, inhibition of Rho in endothelial cells activates caspase-9- and -3-dependent apoptosis, which can be antagonized by cAMP elevation.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2002-09-13 | American journal of physiology. Lung cellular and molecular physiology |