Philipp Schwabl1, Berit A Payer1, Jelena Grahovac2, Sabine Klein3, Thomas Horvatits4, Markus Mitterhauser5, Judith Stift6, Yves Boucher2, Jonel Trebicka3, Michael Trauner4, Bernhard Angermayr1, Valentin Fuhrmann4, Thomas Reiberger7, Markus Peck-Radosavljevic8. 1. Div. of Gastroenterology & Hepatology, Dept. of Internal Medicine III, Medical University Vienna, Austria; Vienna Hepatic Hemodynamic Lab, Vienna, Austria. 2. Edwin L. Steele Laboratory of Tumor Biology, Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA. 3. Div. of Gastroenterology & Hepatology, Dept. of Internal Medicine I, University of Bonn, Germany. 4. Div. of Gastroenterology & Hepatology, Dept. of Internal Medicine III, Medical University Vienna, Austria. 5. Dept. of Nuclear Medicine, Medical University Vienna, Austria. 6. Dept. of Pathology, Medical University Vienna, Austria. 7. Div. of Gastroenterology & Hepatology, Dept. of Internal Medicine III, Medical University Vienna, Austria; Vienna Hepatic Hemodynamic Lab, Vienna, Austria; Edwin L. Steele Laboratory of Tumor Biology, Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA. 8. Div. of Gastroenterology & Hepatology, Dept. of Internal Medicine III, Medical University Vienna, Austria; Vienna Hepatic Hemodynamic Lab, Vienna, Austria. Electronic address: markus.peck@meduniwien.ac.at.
Abstract
BACKGROUND & AIMS: Development of the portal-hypertensive syndrome is mediated by splanchnic inflammation and neoangiogenesis. Since peroxisome proliferator-activated receptor gamma (PPARγ) agonists like pioglitazone (PIO) regulate inflammatory response and inhibit angiogenesis in endothelial cells, we evaluated PIO as treatment for experimental portal hypertension. METHODS: PIO (10 mg/kg) or vehicle (VEH) was administered from day 21-28 after bile duct ligation (BDL), from day 0-7 after partial portal vein ligation (PPVL) or sham-operation (SO), respectively. After treatment, systemic hemodynamics, splanchnic blood flow (SMABF), portal pressure (PP), and portosystemic shunting (PSS) were assessed. Splanchnic and hepatic tissues were analyzed for angiogenic and inflammatory markers. RESULTS: BDL and PPVL showed significantly increased PP, SMABF, and PSS compared to SO-VEH rats. While PIO treatment did not decrease PP or SMABF, PSS was significantly reduced both in cirrhotic (BDL-VEH: 71% to BDL-PIO: 41%; p<0.001) and non-cirrhotic (PPVL-VEH: 62% to PPVL-PIO: 40%; p=0.041) rats. PIO (10 μM, in vitro) inhibited endothelial cell migration and significantly increased PPARγ activity in vivo. In BDL rats, PIO decreased hepatic mRNA levels of PPARγ (p=0.01) and PlGF (p=0.071), and splanchnic mRNA expression of PPARγ (p=0.017), PDGFβ (p=0.053) and TNFα (p=0.075). Accordingly, splanchnic protein expression of PPARγ (p=0.032), VEGFR2 (p=0.035), CD31 (p=0.060) and PDGFβ (p=0.066) were lower in BDL-PIO vs. BDL-VEH animals. In PPVL rats, PIO treatment decreased splanchnic gene expression of Ang2 (-12.4 fold), eNOS (-9.3 fold), PDGF (-7.0 fold), PlGF (-11.9 fold), TGFb (-8.3 fold), VEGF-A (-11.3 fold), VEGFR1 (-5.9 fold), IL1b (-14.4 fold), and IL6 (-9.6 fold). CONCLUSIONS: Pioglitazone treatment decreases portosystemic shunting via modulation of splanchnic inflammation and neoangiogenesis. Pioglitazone should be assessed for potential beneficial effects in patients with portosystemic collaterals due to portal hypertension.
BACKGROUND & AIMS: Development of the portal-hypertensive syndrome is mediated by splanchnic inflammation and neoangiogenesis. Since peroxisome proliferator-activated receptor gamma (PPARγ) agonists like pioglitazone (PIO) regulate inflammatory response and inhibit angiogenesis in endothelial cells, we evaluated PIO as treatment for experimental portal hypertension. METHODS: PIO (10 mg/kg) or vehicle (VEH) was administered from day 21-28 after bile duct ligation (BDL), from day 0-7 after partial portal vein ligation (PPVL) or sham-operation (SO), respectively. After treatment, systemic hemodynamics, splanchnic blood flow (SMABF), portal pressure (PP), and portosystemic shunting (PSS) were assessed. Splanchnic and hepatic tissues were analyzed for angiogenic and inflammatory markers. RESULTS: BDL and PPVL showed significantly increased PP, SMABF, and PSS compared to SO-VEH rats. While PIO treatment did not decrease PP or SMABF, PSS was significantly reduced both in cirrhotic (BDL-VEH: 71% to BDL-PIO: 41%; p<0.001) and non-cirrhotic (PPVL-VEH: 62% to PPVL-PIO: 40%; p=0.041) rats. PIO (10 μM, in vitro) inhibited endothelial cell migration and significantly increased PPARγ activity in vivo. In BDL rats, PIO decreased hepatic mRNA levels of PPARγ (p=0.01) and PlGF (p=0.071), and splanchnic mRNA expression of PPARγ (p=0.017), PDGFβ (p=0.053) and TNFα (p=0.075). Accordingly, splanchnic protein expression of PPARγ (p=0.032), VEGFR2 (p=0.035), CD31 (p=0.060) and PDGFβ (p=0.066) were lower in BDL-PIO vs. BDL-VEH animals. In PPVL rats, PIO treatment decreased splanchnic gene expression of Ang2 (-12.4 fold), eNOS (-9.3 fold), PDGF (-7.0 fold), PlGF (-11.9 fold), TGFb (-8.3 fold), VEGF-A (-11.3 fold), VEGFR1 (-5.9 fold), IL1b (-14.4 fold), and IL6 (-9.6 fold). CONCLUSIONS:Pioglitazone treatment decreases portosystemic shunting via modulation of splanchnic inflammation and neoangiogenesis. Pioglitazone should be assessed for potential beneficial effects in patients with portosystemic collaterals due to portal hypertension.
Authors: Philipp Königshofer; Ksenia Brusilovskaya; Philipp Schwabl; Bruno K Podesser; Michael Trauner; Thomas Reiberger Journal: J Vis Exp Date: 2018-08-01 Impact factor: 1.355