Increase of peroxisome proliferator-activated receptor delta gene expression in the lungs of streptozotocin-induced diabetic rats.
Peroxisome proliferator-activated receptors (PPARs) play key roles in the regulation of energy homeostasis and inflammation while the agonists of PPARalpha and PPARgamma are recently used for therapy in clinic. However, functions of PPARdelta are still unclear. In the present study, we investigated the changes of PPARdelta gene expression in the lung of diabetic rats. The mean level of mRNA transcripts encoding PPARdelta was increased in the lung isolated from streptozotocin-induced diabetic rats (STZ-diabetic rats) to about 1.6-fold of that in normal rats. Exogenous insulin at the dose sufficient to normalize the plasma glucose of STZ-diabetic rats reversed the mRNA level of PPARdelta in lungs after a 4-day treatment. Similar results were also observed in STZ-diabetic rats that received the treatment of phlorizin to reverse the plasma glucose level for 4 days. Otherwise, the protein level of PPARdelta was higher in the lung of STZ-diabetic rats than that in normal rats. Treatment with exogenous insulin or phlorizin reversed this elevated protein level of PPARdelta in the lung of STZ-diabetic rats to near the normal level. The obtained results suggest that increase of plasma glucose is responsible for the higher gene expression of PPARdelta in the lung of STZ-diabetic rats.
Huang
Chang-Jer
CJ
Department of Surgery, Mackay Memorial Hospital, and Mackay Medicine, Nursing and Management College, Taipei City, Taiwan 10401, ROC.
Liu
I-Min
IM
Cheng
Juei-Tang
JT
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D015152:Blotting, Northern; D015153:Blotting, Western; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000188:drug therapy / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D007274:Injections, Intraperitoneal; D049528:Insulin, Long-Acting / Q000008:administration & dosage / Q000627:therapeutic use; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D047494:PPAR delta / Q000235:genetics* / Q000378:metabolism; D010695:Phlorhizin / Q000008:administration & dosage / Q000627:therapeutic use; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin / Q000008:administration & dosage / Q000633:toxicity
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D049528:Insulin, Long-Acting; D047494:PPAR delta; D012333:RNA, Messenger; D013311:Streptozocin; D010695:Phlorhizin