Quiescin sulfhydryl oxidase (QSOX) is expressed in the human atheroma core: possible role in apoptosis.

Abstract

Quiescin sulfhydryl oxidases (QSOXs) catalyze the formation of disulfide bonds in peptides and proteins, and in vertebrates comprise two proteins: QSOX1 and QSOX2. QSOX1, the most extensively studied type, has been implicated in protein folding, production of extracellular matrix, redox regulation, protection from apoptosis, angiogenesis, and cell differentiation. Atherosclerosis is an immunopathological condition in which redox processes, apoptosis, cell differentiation, and matrix secretion/maturation have critical roles. Considering these data, we hypothesized that QSOX1 could be involved in this disease, possibly reducing apoptosis and angiogenesis inside the plaque. QSOX1 labeling in normal human carotid vessels showed predominant expression by endothelium, subendothelium, and adventitia. In atherosclerotic plaques, however, QSOX1 was highly expressed in macrophages at the lipid core. QSOX1 expression was also studied in terms of mRNA and protein in cell types present in plaques under apoptotic or activating stimuli, emulating conditions found in the atherosclerotic process. QSOX1 mRNA increased in endothelial cells and macrophages after the induction of apoptosis. At the protein level, the correlation between apoptosis and QSOX1 expression was not evident in all cell types, possibly because of a rapid secretion of QSOX1. Our results propose for the first time possible roles for QSOX1 in atherosclerosis, being upregulated in endothelial cells and macrophages by apoptosis and cell activation, and possibly controlling these processes, as well as angiogenesis. The quantitative differences in QSOX1 induction may depend on the cell type and also on local factors.

• Authors: Claudia R de Andrade, Beatriz S Stolf, Victor Debbas, Daniela S Rosa, Jorge Kalil, Veronica Coelho, Francisco R M Laurindo
• Journal: In vitro cellular & developmental biology. Animal (In Vitro Cell Dev Biol Anim) Vol. 47 Issue 10 Pg. 716-27 (Dec 2011) ISSN: 1543-706X [Electronic] Germany
• PMID: 22069028 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antigens, CD
• Antigens, Differentiation, Myelomonocytic
• CD68 antigen, human
• Angiotensin II
• Brefeldin A
• Oxidoreductases Acting on Sulfur Group Donors
• QSOX1 protein, human
• Camptothecin

Topics

• Angiotensin II (pharmacology)
• Antigens, CD (metabolism)
• Antigens, Differentiation, Myelomonocytic (metabolism)
• Apoptosis (drug effects)
• Blotting, Western
• Brefeldin A (pharmacology)
• Camptothecin (pharmacology)
• Carotid Arteries (drug effects, enzymology, pathology)
• Cell Differentiation (drug effects)
• HeLa Cells
• Human Umbilical Vein Endothelial Cells (cytology, metabolism)
• Humans
• Immunohistochemistry
• Oxidoreductases Acting on Sulfur Group Donors (metabolism)
• Plaque, Atherosclerotic (enzymology, pathology)