Peroxisome proliferator-activated receptor-alpha activator fenofibrate prevents high-fat diet-induced renal lipotoxicity in spontaneously hypertensive rats.
We investigated the effects of a high-fat (HF) diet and peroxisome proliferator-activated receptor (PPAR)-alpha activation on the intrarenal lipotoxicity associated with the renin-angiotensin system (RAS) and oxidative stress using spontaneously hypertensive (SHR) rats. Male SHR and Wistar-Kyoto (WKY) rats at 8 weeks of age were fed either a normal-fat diet or an HF diet without or with fenofibrate treatment for 12 weeks. Severe intrarenal lipid accumulation was noted in the SHR rats fed an HF diet than in WYK rats fed an HF diet (P<0.05). This lipid accumulation was associated with a 70% decrease in renal PPARalpha expression in SHR rats, whereas an HF diet increased the expression of PPARalpha in WKY rats by threefold. An HF diet also activated intrarenal, not systemic, RAS and induced oxidative stress associated with reduced nitric oxide (NO) bioavailability. By contrast, fenofibrate attenuated weight gain, fat mass and insulin resistance. Fenofibrate recovered HF diet-induced decreases in intrarenal PPARalpha expression and fat accumulation, and abolished intrarenal RAS activation and oxidative stress in SHR-HF animals (P<0.01). These activities conferred protection against increased blood pressure (BP), glomerulosclerosis and renal inflammation. Intrarenal free fatty acid and triglyceride concentrations were positively correlated with angiotensin II (gamma=0.63, 0.36) and 24-h urinary 8-hydroxy-deoxyguanosine (gamma=0.36, 0.39), and negatively correlated with PPARalpha contents (gamma=-0.47, -0.44; P<0.05). An HF diet-induced lipotoxicity by depletion of intrarenal PPARalpha aggravated BP and renal inflammation as a result of intrarenal RAS activation and oxidative stress. Therefore, intervention with PPARalpha activators can effectively prevent diet-induced renal lipotoxicity in hypertensive rats.
Shin
Seok Joon
SJ
Division of Nephrology, Department of Internal Medicine,The Catholic University of Korea, Seoul, Korea.
Lim
Ji Hee
JH
Chung
Sungjin
S
Youn
Dong-Ye
DY
Chung
Hyun Wha
HW
Kim
Hyung Wook
HW
Lee
Jeong-Hwa
JH
Chang
Yoon Sik
YS
Park
Cheol Whee
CW
D052242:Adiponectin / Q000097:blood; D000273:Adipose Tissue / Q000187:drug effects; D000804:Angiotensin II / Q000378:metabolism; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004041:Dietary Fats / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D011345:Fenofibrate / Q000494:pharmacology*; D006442:Glycated Hemoglobin / Q000378:metabolism; D007150:Immunohistochemistry; D007674:Kidney Diseases / Q000139:chemically induced* / Q000517:prevention & control*; D007677:Kidney Function Tests; D050356:Lipid Metabolism / Q000187:drug effects; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D047493:PPAR alpha / Q000819:agonists*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000302:isolation & purification; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012084:Renin-Angiotensin System / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction
D052242:Adiponectin; D000804:Angiotensin II; D000806:Angiotensin-Converting Enzyme Inhibitors; D004041:Dietary Fats; D011345:Fenofibrate; D006442:Glycated Hemoglobin; D047493:PPAR alpha; D012333:RNA, Messenger