Faculty Collaboration Database

Native low-density lipoprotein induces endothelial nitric oxide synthase dysfunction: role of heat shock protein 90 and caveolin-1. Free Radic Biol Med 2002 Jul 01;33(1):52-62

Date

06/28/2002

Pubmed ID

12086682

DOI

10.1016/s0891-5849(02)00851-1

Scopus ID

2-s2.0-0036628727   39 Citations

Abstract

Although native LDL (n-LDL) is well recognized for inducing endothelial cell (EC) dysfunction, the mechanisms remain unclear. One hypothesis is n-LDL increases caveolin-1 (Cav-1), which decreases nitric oxide (*NO) production by binding endothelial nitric oxide synthase (eNOS) in an inactive state. Another is n-LDL increases superoxide anion (O(2)(*-)), which inactivates *NO. To test these hypotheses, EC were incubated with n-LDL and then analyzed for *NO, O(2)(*-), phospho-eNOS (S1179), eNOS, Cav-1, calmodulin (CaM), and heat shock protein 90 (hsp90). n-LDL increased NOx by more than 4-fold while having little effect on A23187-stimulated nitrite production. In contrast, n-LDL decreased cGMP under basal and A23187-stimulated conditions and increased O(2)(*-) by a mechanism that could be inhibited by L-nitroargininemethylester (L-NAME) and BAPTA/AM. n-LDL increased phospho-eNOS by 149%, eNOS by approximately 34%, and Cav-1 by 28%, and decreased the association of hsp90 with eNOS by 49%. n-LDL did not appear to alter eNOS distribution between membrane fractions (approximately 85%) and cytosol (approximately 15%). Only 3-6% of eNOS in membrane fractions was associated with Cav-1. These data support the hypothesis that n-LDL increases O(2)(*-), which scavenges *NO, and suggest that n-LDL uncouples eNOS activity by decreasing the association of hsp90 as an initial step in signaling eNOS to generate O(2)(*-).

Author List

Pritchard KA, Ackerman AW, Ou J, Curtis M, Smalley DM, Fontana JT, Stemerman MB, Sessa WC

Author

Kirkwood A. Pritchard PhD Professor in the Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Biological Transport
Blotting, Western
Calmodulin
Cattle
Caveolin 1
Caveolins
Cells, Cultured
Chelating Agents
Cyclic GMP
Egtazic Acid
Endothelium, Vascular
Enzyme Activation
Enzyme Inhibitors
HSP90 Heat-Shock Proteins
Humans
Lipoproteins, LDL
NG-Nitroarginine Methyl Ester
Nitric Oxide
Nitric Oxide Synthase
Nitric Oxide Synthase Type III
Nitrites
Phosphorylation
Superoxides