Pulmonary arterial hypertension leads to liver fibrosis in the SU5416/hypoxia model in rats

F Hamberger; E Legchenko; P Chouvarine; D Jonigk; MP Manns; G Hansmann; I Mederacke

doi:10.1055/s-0039-3402126

Zeitschrift für Gastroenterologie, Table of Contents

Z Gastroenterol 2020; 58(01): e11
DOI: 10.1055/s-0039-3402126

Poster Visit Session I Basic Hepatology (Fibrogenesis, NPC, Transport): Friday, February 14, 2020, 12:30 pm – 1:15 pm, Lecture Hall P1

Georg Thieme Verlag KG Stuttgart · New York

Pulmonary arterial hypertension leads to liver fibrosis in the SU5416/hypoxia model in rats

F Hamberger

¹Medizinische Hochschule Hannover, Gastroenterologie, Hannover, Germany

,

E Legchenko

²University of Cambridge, Cambridge, United Kingdom

,

P Chouvarine

³Medizinische Hochschule Hannover, Hannover, Germany

,

D Jonigk

⁴Medizinische Hochschule Hannover, Pathologie, Hannover, Germany

,

MP Manns

¹Medizinische Hochschule Hannover, Gastroenterologie, Hannover, Germany

,

G Hansmann

⁵Medizinische Hochschule Hannover, Kardiologie und Pädiatrische Intensivmedizin, Hannover, Germany

,

I Mederacke

¹Medizinische Hochschule Hannover, Gastroenterologie, Hannover, Germany

› Author Affiliations

Abstract

Full Text

Questions:

Patients with pulmonary arterial hypertension (PAH) may develop liver fibrosis/cirrhosis and portal hypertension over time (Reverter, Seijo, & Bosch, 2012). The underlying mechanisms for this are largely unknown. We and others have shown, that the SU5416/hypoxia (SuHx) rat model is a model of severe PAH, whether these animals also develop liver fibrosis is unknown.

Methods:

Six to eight-week old male Sprague-Dawley rats were purchased from Charles River and divided into three different treatment groups: (A) normoxia (ConNx), (B) ConHx [injected once s.c. with vehicle (DMSO), then exposed to chronic hypoxia (FiO2 0.1) for 3 weeks, followed by a 6-week period in room air (FiO2 0.21)]; (C) SuHx [injected with the VEGFR2 inhibitor SU5416 Σ, 20 mg/kg per dose s.c. dissolved in DMSO and subsequently exposed to chronic hypoxia (3 weeks), followed by 6 weeks of room air]. At the end of treatment animals were sacrificed and livers were harvested for subsequent analysis. H&E, Masson"s trichrome and Picrosirius red stainings were performed according to routine protocols. RNA for qPCR and transcriptome analysis was isolated using TRIzol reagent.

Results:

Picrosirius red staining showed no difference in liver fibrosis between rats in the normoxia (ConNx) and hypoxia (ConHx) groups (0.88-fold induction, p = 0.9734). Rats in the SuHx treatment arm developed significant PAH (Right ventricular systolic pressure (RSVP) ConNx vs. SuHx, 29 vs. 91 mmHg, p < 0.0001) and also displayed significant liver fibrosis (1.60-fold induction compared to ConNx, p < 0.01). QPCR analysis confirmed induction of fibrogenic genes Timp1 (2.12-fold induction, p < 0.05) and col1a1 (3.13-fold induction, p < 0.01) in the SuHx rats. H&E- and trichrome staining also showed immune cell infiltration in the livers of the SuHx treated animals. RNA-sequencing of whole liver tissue revealed an upregulation of the inflammatory response, T-cell activation, cell growth and fibroblast proliferation in animals with PAH and liver fibrosis.

Conclusions:

Pulmonary arterial hypertension leads to liver fibrosis in the SU5416/hypoxia model in rats. Patients with PAH should therefore also be screened for signs of liver fibrosis.