title: Protein kinase C beta 1 overexpression augments phorbol ester-induced increase in endothelial permeability.
abstract: We studied the postulated involvement of the protein kinase C beta 1 (PKC beta 1) isoform in the regulation of endothelial permeability using human dermal microvascular endothelial cell line (HMEC-1). We overexpressed the recombinant PKC beta 1 gene via retroviral-mediated transduction in these cells. PKC beta 1 gene transfer was stable, and PKC beta 1 protein production was persistent for at least 1 month posttransduction. Addition of 2 x 10(-9) M and 2 x 10(-8) M phorbol 12-myristate 13-acetate (PMA) to the control (nontransduced) HMEC-1 cells increased the transendothelial 125I-albumin clearance rate (an index of endothelial permeability) from 2.5 +/- 0.2 x 10(-2) microliters/min to 5.4 +/- 1.2 x 10(-2) microliters/min and 16.8 +/- 3.1 x 10(-2) microliters/min, respectively. However, addition of 2 x 10(-9) M PMA to PKC beta 1-overexpressing HMEC-1 cells produced a maximal increase in the transendothelial 125I-albumin clearance rate of 15.9 +/- 2.0 x 10(-2) microliters/min. Challenge of these cells with 2 x 10(-8) M PMA did not further augment the increase in permeability. Activation with PMA was associated with the translocation of the PKC beta 1 from the cytosol to the membrane. These data show that PKC beta 1 overexpression augments the increase in endothelial permeability in response to PKC activation, suggesting an important function for the PKC beta 1 isoform in the regulation of endothelial barrier.
authors.affiliation: Department of Pharmacology, Rush Presbyterian-St. Luke's Medical Center/Rush Medical College, Chicago, Illinois 60612, USA.
authors.forename: P G
authors.initials: PG
authors.lastname: Nagpala
authors.forename: A B
authors.initials: AB
authors.lastname: Malik
authors.forename: P T
authors.initials: PT
authors.lastname: Vuong
authors.forename: H
authors.initials: H
authors.lastname: Lum
mesh_terms: D002199:Capillary Permeability / Q000187:drug effects*; D002460:Cell Line; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D064546:Protein Kinase C beta; D011994:Recombinant Proteins; D012190:Retroviridae / Q000502:physiology; D012709:Serum Albumin / Q000493:pharmacokinetics; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014162:Transfection
chemical_list: D011994:Recombinant Proteins; D012709:Serum Albumin; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D013755:Tetradecanoylphorbol Acetate