Beneficial Effects of the Peroxisome Proliferator-Activated Receptor α/γ Agonist Aleglitazar on Progressive Hepatic and Splanchnic Abnormalities in Cirrhotic Rats with Portal Hypertension

Recent studies have reported that peroxisome proliferator-activated receptor α (PPARα) agonist decreases intrahepatic resistance, whereas PPARγ agonist reduces portosystemic shunts (PSSs) and splanchnic angiogenesis in cirrhotic rats. The present study investigated the effects of a 21-day treatment with the dual PPARα/γ agonist aleglitazar (Ale) on progressive abnormalities in bile-duct–ligated and thioacetamide-induced cirrhotic rats with portal hypertension (PH). In vivo and in vitro effects were evaluated. Chronic Ale treatment significantly up-regulated PPARα/PPARγ receptors and down-regulated tumor necrosis factor-α (TNF-α) and NF-κB expression in the liver, splanchnic tissues, collateral vessels, and intestines of cirrhotic rats with PH. Notably, Ale improved PH by the suppression of systemic/tissue inflammation, hepatic fibrosis, hepatic Rho-kinase–mediated endothelin-1 hyperresponsiveness, intrahepatic/mesenteric angiogenesis, vascular endothelial growth factor expression, PSS, intestinal mucosal injury, and hyperpermeability in cirrhotic rats. Acute Ale treatment inhibited TNF-α–enhanced endothelin-1–induced contraction of primary hepatic stellate cells, vascular endothelial growth factor–induced migration/angiogenesis of liver sinusoidal endothelial cells, and TNF-α–induced disruption of Caco-2 cell monolayer-epithelial barrier. The present study suggested that Ale can potentially treat relevant abnormalities through the inhibition of inflammatory, vasoconstrictive, angiogenic, and mucosal-disrupted pathogenic markers in cirrhosis. Overall, chronic Ale treatment ameliorated PH syndrome by the suppression of hepatic fibrogenesis, neoangiogenesis, vasoconstrictor hyperresponsiveness, splanchnic vasodilatation, and PSS; and decreased intestinal mucosal injury and hyperpermeability in cirrhotic rats.