title: Lysophosphatidylcholine increases endothelial permeability: role of PKCalpha and RhoA cross talk.
abstract: Lysophosphatidylcholine (LPC) is a bioactive proinflammatory lipid that can be generated by pathological activities. We investigated the hypothesis that LPC signals increase in endothelial permeability. Stimulation of human dermal microvascular endothelial cells and bovine pulmonary microvascular endothelial cells with LPC (10-50 microM) induced decreases (within minutes) in transendothelial electrical resistance and increase of endothelial permeability. LPC activated (within 5 min) membrane-associated PKC phosphotransferase activity in the absence of translocation. Affinity-binding analysis indicated that LPC induced increases (also by 5 min) of GTP-bound RhoA, but not Rac1 or Cdc42. By 60 min, both signaling pathways decreased toward baseline. Inhibition of RhoA with C3 transferase inhibited approximately 50% of LPC-induced resistance decrease. Pretreatment with PKC inhibitor Gö-6983 (concentrations selective for classic PKC), PMA-induced depletion of PKCalpha, and transfection of antisense PKCalpha oligonucleotide each prevented 40-50% of the LPC-induced resistance decrease. Furthermore, these three PKC inhibition strategies inhibited 60-80% of the LPC-induced GTP-bound RhoA. These results show that LPC directly impairs the endothelial barrier function that was dependent, at least in part, on cross talk of PKCalpha and RhoA signals. The evidence indicates that elevated LPC levels can contribute to the activation of a proinflammatory endothelial phenotype.
authors.affiliation: Department of Pharmacology, Rush Univ. Medical Center, 1735 W. Harrison St., Cohn Research Bldg., Rm. 416, Chicago, IL 60612, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Huang
authors.forename: Papasani V
authors.initials: PV
authors.lastname: Subbaiah
authors.forename: Oksana
authors.initials: O
authors.lastname: Holian
authors.forename: Jihang
authors.initials: J
authors.lastname: Zhang
authors.forename: Arnold
authors.initials: A
authors.lastname: Johnson
authors.forename: Nancy
authors.initials: N
authors.lastname: Gertzberg
authors.forename: Hazel
authors.initials: H
authors.lastname: Lum
mesh_terms: D000818:Animals; D002199:Capillary Permeability / Q000187:drug effects*; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D017097:Electric Impedance; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D004789:Enzyme Activation; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000098:blood supply; D008244:Lysophosphatidylcholines / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism*; D051571:Protein Kinase C-alpha; D021381:Protein Transport; D015398:Signal Transduction; D012867:Skin / Q000098:blood supply; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D008244:Lysophosphatidylcholines; D006160:Guanosine Triphosphate; C496628:PRKCA protein, human; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D020764:cdc42 GTP-Binding Protein; D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein