Adiponectin receptor gene expression in human skeletal muscle cells is not regulated by fibrates and thiazolidinediones.
BACKGROUND
Thiazolidinediones as PPARgamma agonists and fibrates as PPARalpha agonists improve insulin sensitivity in insulin-responsive tissues. Recent data show an induction of adiponectin receptor 2 (AdipoR2) by PPARalpha and PPARgamma agonists in human macrophages.


OBJECTIVE
In this study, we examined the effects of thiazolidinediones and fibrates on the expression of adiponectin receptors in human skeletal muscle cells, an important cell type in the context of insulin resistance.


RESULTS
In vitro differentiated human myotubes treated with troglitazone or rosiglitazone (20 h) showed no significant changes in AdipoR1 and AdipoR2 mRNA expression. PPARgamma activation was controlled by determination of PPARgamma mRNA induction. Likewise, differentiated myotubes treated with Wy-14,643 or fenofibrate (20 h) revealed no significant regulation of AdipoR1 and AdipoR2 mRNA. PPARalpha activation was assessed by measuring PDHK4 mRNA expression.


CONCLUSIONS
Induction of AdipoR gene expression in human skeletal muscle cells is not involved in the insulin-sensitizing effects of thiazolidinediones or fibrates.
Kaltenbach
S
S
Department of Endocrinology, Metabolism and Pathobiochemistry, Medical Clinic Tübingen, Eberhard-Karls-University Tübingen, Germany.
Staiger
H
H
Weisser
M
M
Haas
C
C
Stumvoll
M
M
Machicao
F
F
Häring
H-U
HU
D000328:Adult; D002478:Cells, Cultured; D002839:Chromans / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D044943:Fatty Acid Desaturases; D005260:Female; D011345:Fenofibrate / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D047495:PPAR gamma / Q000032:analysis; D020025:Peroxisome Proliferators / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D054419:Receptors, Adiponectin; D011956:Receptors, Cell Surface / Q000032:analysis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077154:Rosiglitazone; D018709:Statistics, Nonparametric; D013230:Stearoyl-CoA Desaturase / Q000032:analysis; D045162:Thiazolidinediones / Q000494:pharmacology; D000077288:Troglitazone
C475418:ADIPOR1 protein, human; C475420:ADIPOR2 protein, human; D002839:Chromans; D007004:Hypoglycemic Agents; D047495:PPAR gamma; D020025:Peroxisome Proliferators; D011743:Pyrimidines; D012333:RNA, Messenger; D054419:Receptors, Adiponectin; D011956:Receptors, Cell Surface; D045162:Thiazolidinediones; D000077154:Rosiglitazone; C006253:pirinixic acid; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C533241:FADS2 protein, human; D000077288:Troglitazone; D011345:Fenofibrate