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Protein kinase C β 1 overexpression augments phorbol ester‐induced increase in endothelial permeability
Author(s) -
Nagpala Pablito G.,
Malik Asrar B.,
Vuong Phuoc T.,
Lum Hazel
Publication year - 1996
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(199602)166:2<249::aid-jcp2>3.0.co;2-p
Subject(s) - protein kinase c , phorbol ester , microbiology and biotechnology , protein kinase a , chemistry , permeability (electromagnetism) , kinase , biochemistry , biology , membrane
We studied the postulated involvement of the protein kinase C β 1 (PKCβ 1 ) isoform in the regulation of endothelial permeability using human dermal microvascular endothelial cell line (HMEC‐1). We overexpressed the recombinant PKCβ 1 gene via retroviral‐mediated transduction in these cells. PKCβ 1 gene transfer was stable, and PKCβ 1 protein production was persistent for at least 1 month posttransduction. Addition of 2 × 10 −9 M and 2 × 10 −8 M phorbol 12‐myristate 13‐acetate (PMA) to the control (nontransduced) HMEC‐1 cells increased the transendothelial 125 I‐albumin clearance rate (an index of endothelial permeability) from 2.5 ± 0.2 × 10 −2 μl/min to 5.4 ± 1.2 × 10 −2 μl/min and 16.8 ± 3.1 × 10 −2 μl/min, respectively. However, addition of 2 × 10 −9 M PMA to PKCβ 1 ‐overexpressing HMEC‐1 cells produced a maximal increase in the transendothelial 125 I‐albumin clearance rate of 15.9 ± 2.0 × 10 −2 μl/min. Challenge of these cells with 2 × 10 −8 M PMA did not further augment the increase in permeability. Activation with PMA was associated with the translocation of the PKCβ 1 from the cytosol to the membrane. These data show that PKCβ 1 overexpression augments the increase in endothelial permeability in response to PKC activation, suggesting an important function for the PKCβ 1 isoform in the regulation of endothelial barrier. © 1996 Wiley‐Liss, Inc.