Expression of vasoactive proteins in gastric antral mucosa reflects vascular dysfunction in patients with cirrhosis and portal hypertension

Abstract

Background & Aims Patients with cirrhosis display hypocontractility of splanchnic vessels because of dysregulation of vasoactive proteins, such as decreased effect of RhoA/ROCK and increased activity of β‐Arrestin‐2 and eNOS. However, it is unknown whether the dysregulation of vasoactive proteins is displayed in other vessels. We investigated whether expression of vasoactive proteins can be evaluated in gastric mucosa vessels. Methods Biopsies from the gastric mucosa of 111 patients with cirrhosis were collected at three different centres and from 13 controls. Forty‐nine patients had received TIPS. Portal pressure gradient was measured in 49 patients with TIPS and in 16 patients without TIPS. Biopsies from the antrum were conserved in formaldehyde for immunohistochemistry or shock‐frozen for PCR and Western blot. Results The mucosal transcription of vascular markers (αSMA, CD31) was higher in cirrhotic patients than controls, which was confirmed by immunohistochemistry. On average, relative mucosal levels of RhoA and ROCK were lower, while β‐Arrestin‐2 levels were higher in cirrhotic patients compared to controls. Transcriptional levels of eNOS increased with presence of ascites and grade of oesophageal varices. Patients with TIPS showed less pronounced markers of vascular dysfunction in gastric mucosa. Conclusion This is the first evidence that the expression of vasoactive proteins in mucosa from the gastric antrum of patients with cirrhosis reflects their vascular dysfunction and possibly changes after therapeutic interventions.