TY - JOUR
T1 - Association of scavenger receptors in adipose tissue with insulin resistance in nondiabetic humans
AU - Rasouli, Neda
AU - Yao-Borengasser, Aiwei
AU - Varma, Vijayalakshmi
AU - Spencer, Horace J.
AU - McGehee, Robert E.
AU - Peterson, Charlotte A.
AU - Mehta, Jawahar L.
AU - Kern, Philip A.
PY - 2009/9
Y1 - 2009/9
N2 - OBJECTIVE-: Scavenger receptors play crucial roles in the pathogenesis of atherosclerosis, but their role in insulin resistance has not been explored. We hypothesized that scavenger receptors are present in human adipose tissue resident macrophages, and their gene expression is regulated by adiponectin and thaizolidinediones. METHODS AND RESULTS-: The gene expression of scavenger receptors including scavenger receptor-A (SRA), CD36, and lectin-like oxidized LDL receptor-1 (LOX-1) were studied in subcutaneous adipose tissue of nondiabetic subjects and in vitro. Adipose tissue SRA expression was independently associated with insulin resistance. Pioglitazone downregulated SRA gene expression in adipose tissue of subjects with impaired glucose tolerance and decreased LOX-1 mRNA in vitro. Macrophage LOX-1 expression was decreased when macrophages were cocultured with adipocytes or when exposed to adipocyte conditioned medium. Adding adiponectin neutralizing antibody resulted in a 2-fold increase in LOX-1 gene expression demonstrating that adiponectin regulates LOX-1 expression. CONCLUSION-: Adipose tissue scavenger receptors are strongly associated with insulin resistance. Pioglitazone and adiponectin regulate gene expression of SRA and LOX-1, and this may have clinical implications in arresting the untoward sequalae of insulin resistance and diabetes, including accelerated atherosclerosis.
AB - OBJECTIVE-: Scavenger receptors play crucial roles in the pathogenesis of atherosclerosis, but their role in insulin resistance has not been explored. We hypothesized that scavenger receptors are present in human adipose tissue resident macrophages, and their gene expression is regulated by adiponectin and thaizolidinediones. METHODS AND RESULTS-: The gene expression of scavenger receptors including scavenger receptor-A (SRA), CD36, and lectin-like oxidized LDL receptor-1 (LOX-1) were studied in subcutaneous adipose tissue of nondiabetic subjects and in vitro. Adipose tissue SRA expression was independently associated with insulin resistance. Pioglitazone downregulated SRA gene expression in adipose tissue of subjects with impaired glucose tolerance and decreased LOX-1 mRNA in vitro. Macrophage LOX-1 expression was decreased when macrophages were cocultured with adipocytes or when exposed to adipocyte conditioned medium. Adding adiponectin neutralizing antibody resulted in a 2-fold increase in LOX-1 gene expression demonstrating that adiponectin regulates LOX-1 expression. CONCLUSION-: Adipose tissue scavenger receptors are strongly associated with insulin resistance. Pioglitazone and adiponectin regulate gene expression of SRA and LOX-1, and this may have clinical implications in arresting the untoward sequalae of insulin resistance and diabetes, including accelerated atherosclerosis.
KW - Adiponectin
KW - Insulin resistance
KW - Pioglitazone
KW - Scavenger receptors
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U2 - 10.1161/ATVBAHA.109.186957
DO - 10.1161/ATVBAHA.109.186957
M3 - Article
C2 - 19667111
AN - SCOPUS:69849113860
SN - 1079-5642
VL - 29
SP - 1328
EP - 1335
JO - Arteriosclerosis, Thrombosis, and Vascular Biology
JF - Arteriosclerosis, Thrombosis, and Vascular Biology
IS - 9
ER -