Fimasartan Ameliorates Nonalcoholic Fatty Liver Disease through PPARδ Regulation in Hyperlipidemic and Hypertensive Conditions

Hindawi PPAR Research Volume 2017, Article ID 8048720, 14 pages https://doi.org/10.1155/2017/8048720 Research Article Fimasartan Ameliorates Nonalcoholic Fatty Liver Disease through PPAR𝛿 Regulation in Hyperlipidemic and Hypertensive Conditions Yong-Jik Lee,1 Yoo-Na Jang,1 Yoon-Mi Han,1 Hyun-Min Kim,1 Jong-Min Jeong,1 and Hong Seog Seo1,2 1 Cardiovascular Center, Guro Hospital, Korea University, 80 Guro-dong, Guro-gu, Seoul 152-703, Republic of Korea The Korea University-Korea Institute of Science and Technology (KU-KIST) Graduate School of Converging Science and Technology, Seoul, Republic of Korea 2 Correspondence should be addressed to Hong Seog Seo; Received 13 December 2016; Revised 1 February 2017; Accepted 19 February 2017; Published 13 March 2017 Academic Editor: Brian N. Finck Copyright © 2017 Yong-Jik Lee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. To investigate the effects of fimasartan on nonalcoholic fatty liver disease in hyperlipidemic and hypertensive conditions, the levels of biomarkers related to fatty acid metabolism were determined in HepG2 and differentiated 3T3-L1 cells treated by high fatty acid and liver and visceral fat tissue samples of spontaneously hypertensive rats (SHRs) given high-fat diet. In HepG2 cells and liver tissues, fimasartan was shown to increase the protein levels of peroxisome proliferator-activated receptor delta (PPAR𝛿), phosphorylated 5󸀠 adenosine monophosphate-activated protein kinase (p-AMPK), phosphorylated acetyl-CoA carboxylase (pACC), malonyl-CoA decarboxylase (MCD), medium chain acyl-CoA dehydrogenase (MCAD), and peroxisome proliferatoractivated receptor gamma coactivator 1-alpha (PGC-1𝛼), and it led to a decrease in the protein levels of 11 beta-hydroxysteroid dehydrogenase 1 (11𝛽-HSDH1), fatty acid synthase (FAS), and tumor necrosis factor-alpha (TNF-𝛼). Fimasartan decreased lipid contents in HepG2 and differentiated 3T3-L1 cells and liver tissues. In addition, fimasartan increased the adiponectin level in visceral fat tissues. The antiadipogenic effects of fimasartan were offset by PPAR𝛿 antagonist (GSK0660). Consequently, fimasartan ameliorates nonalcoholic fatty liver disease mainly through the activation of oxidative metabolism represented by PPAR𝛿-AMPKPGC-1𝛼 pathway. 1. Introduction Nonalcoholic fatty liver disease (NAFLD) is a widespread disease defined by excessive fat accumulation in the form of triglycerides (steatosis) in the liver (histologically, over 5% of hepatocytes). In some patients, NAFLD can progress to cirrhosis and further to hepatocarcinoma. NAFLD patients belonging to one subgroup have liver cell injury and inflammation, in addition to excessive fat (steatohepatitis). The latter condition, designated nonalcoholic steatohepatitis (NASH), is virtually indistinguishable histologically from alcoholic steatohepatitis (ASH), and it represents a progressed NAFLD. It was reported that various diseases, such as obesity, diabetes, and hyperlipidemia, can induce the progression of NAFLD and NASH [1–3]. Furthermore, NASH can be used as a representative clinical index together with hypertension, cardiovascular disease, and complications of diabetes [4]. Several compounds such as fenofibrate, a peroxisome proliferator-activated receptor alpha (PPAR𝛼) agonist, or statin may help NAFLD and NASH treatments [5–7]. Representative angiotensin II type 1 receptor (AGTR1) blocker, telmisartan, ameliorates NAFLD and NASH through the suppression of macrophage infiltration into the liver, the reduction of adipocyte size, and the elevation of serum adiponectin [8]. Fimasartan (2-n-butyl-5-dimethylaminothiocarbonylmethyl-6-methyl-3-{[2-(1H-tetrazole-5-yl)biphenyl-4yl]methyl}pyrimidine-4(3H)-one potassium salt trihydrate) represents a nonpeptide angiotensin receptor blocker, with 2 PPAR Research selective AGTR1 blocking effects, which was approved by the Korean Food and Drug Administration in 2010 for the treatment of essential hypertension [9, 10]. Although the effects of other drugs belonging to sartan class, such as telmisartan, on lipid metabolism in liver are relatively well studied, the effects of fimasartan in this context have not been completely elucidated. In this study, to investigate the potential of fimasartan in NAFLD treatment in hyperlipidemic and hypertensive conditions, the expression levels of various biomarkers related to fatty acid metabolism were determined in HepG2 and differentiated 3T3-L1 cells and liver and visceral fat tissues harvested from spontaneously hypertensive rats (SHRs) given high-fat diet. In addition, while studies on nuclear receptors such as PPAR𝛾 and PPAR𝛼 in NAFLD have been relatively well studied, researches on the relation between NAFLD and PPAR𝛿 are very deficient. Furthermore, the lowered catabolic metabolism is involved with metabolic diseases such as NAFLD and obesity, and it is well known that PPAR𝛿 activates catabolic reactions in cells. So, our study was primarily focused on the relationship between fimasartan and PPAR𝛿 in NAFLD. This report presents novel findings showing the relationships between fatty acid metabolism, fatty liver disease, and AGTR1 blocker, fimasartan. kinase (AMPK), phosphorylated AMPK (p-AMPK), acetylCoA carboxylase (ACC), and phosphorylated ACC (p-ACC) were bought from Cell Signaling Technology, Inc. (Danvers, MA, USA). Primary antibodies for peroxisome proliferatoractivated receptor delta (PPAR𝛿), peroxisome proliferatoractivated receptor alpha (PPAR𝛼), malonyl-CoA decarboxylase (MCD), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1𝛼) and rat adiponectin ELISA kit were supplied from Abcam (Cambridge, UK). Primary antibodies for anti-tumor necrosis factor-alpha (TNF𝛼) and anti-fatty acid synthase (FAS) were purchased from Novus (Littleton, CO, USA). Chemiluminescent substrate and enhancer solutions were obtained from Bio-Rad (Hercules, CA, USA). Immunohistochemistry reagents were purchased from Vector Laboratories (Burlingame, CA, USA). Reagents to measure the concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL cholesterol), and low-density lipoprotein cholesterol (LDL cholesterol) were bought from Kyowa Medex Co., Ltd. (Tokyo, Japan). Reagents to estimate the activities for glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were purchased from DENKA SEIKEN Co., Ltd. (Tokyo, Japan). Rat adenosine triphosphate (ATP) ELISA kit was obtained from MyBioSource (San Diego, CA, USA), and triglyceride colorimetric assay kit was bought from Cayman Chemical Company (Ann Arbor, MI, USA). 2. Materials and Methods 2.2. Cell Culture. HepG2 cells were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM) containing 10% FBS and 1% AA solution in 37∘ C, 5% CO2 incubator. The medium was re (...truncated)