Effect of PPAR-alpha and -gamma agonist on the expression of visfatin, adiponectin, and TNF-alpha in visceral fat of OLETF rats.
A variety of adipocytokines and peptides secreted from adipocytes have been considered to play a crucial role in obesity, insulin resistance, and type 2 diabetes. Recently, visfatin, a new adipocytokine, known as a pre-B cell colony-enhancing factor, has been isolated from visceral fat deposits. It has been shown to activate insulin receptors in a manner different from insulin. To understand the role of adipocytokines in improving insulin sensitivity via activation of the nuclear receptor peroxisome proliferator-activated receptor-alpha (PPAR-alpha) and -gamma (PPAR-gamma), we examined the expression of visfatin, adiponectin, and TNF-alpha in visceral fat depots of Otsuka Long-Evans Tokushima fatty (OLETF) rats from early to advanced diabetic stage (from 28 to 40 weeks of age). Serum glucose and insulin concentrations significantly (P<0.05) decreased in rosiglitazone or fenofibrate-treated OLETF rats compared to untreated OLETF rats. Rosiglitazone significantly increased serum adiponectin concentration from 20 to 40 weeks of age (P<0.05), whereas fenofibrate reduced TNF-alpha concentration. The expression of visfatin and adiponectin mRNA in visceral fat deposits was elevated by rosiglitazone or fenofibrate treatments when compared to untreated OLETF rats (P<0.05), whereas, TNF-alpha mRNA was down-regulated by these drugs (P<0.05). These results suggest that rosiglitazone and fenofibrate may prevent type 2 diabetes by regulating adipocytokines including visfatin, adiponectin, and TNF-alpha.
Choi
K C
KC
Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul 152-050, Republic of Korea.
Ryu
O H
OH
Lee
K W
KW
Kim
H Y
HY
Seo
J A
JA
Kim
S G
SG
Kim
N H
NH
Choi
D S
DS
Baik
S H
SH
Choi
K M
KM
D052242:Adiponectin; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight / Q000187:drug effects; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D011345:Fenofibrate / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood / Q000235:genetics / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D054409:Nicotinamide Phosphoribosyltransferase; D047493:PPAR alpha / Q000819:agonists*; D047495:PPAR gamma / Q000819:agonists*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020334:Rats, Inbred OLETF; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D014781:Viscera
D052242:Adiponectin; D001786:Blood Glucose; D016207:Cytokines; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D008055:Lipids; D047493:PPAR alpha; D047495:PPAR gamma; D012333:RNA, Messenger; D045162:Thiazolidinediones; D014409:Tumor Necrosis Factor-alpha; D000077154:Rosiglitazone; D054409:Nicotinamide Phosphoribosyltransferase; C504970:nicotinamide phosphoribosyltransferase, rat; D011345:Fenofibrate