Angiotensin-converting enzyme 2 autoantibodies: further evidence for a role of the renin-angiotensin system in inflammation

Mark C Chappell

doi:10.1186/ar3052

Abstract

Traditionally viewed as important in the regulation of blood pressure, the renin-angiotensin system - and specifically the angiotensin-converting enzyme (ACE)-angiotensin (Ang) II-AT1 receptor axis - may play a prominent role to promote inflammation and fibrosis. ACE2, a new component of the renin-angiotensin system, has emerged as a key enzyme that selectively degrades Ang II and generates Ang-(1-7), a bioactive peptide with anti-inflammatory and anti-fibrotic actions. Takahashi and colleagues demonstrate circulating titers of inhibitory autoantibodies against ACE2 in patients with systemic sclerosis. The current study reveals a potentially novel mechanism to attenuate the catalytic activity of ACE2, thereby promoting the actions of Ang II.

Highlights

Viewed as important in the regulation of blood pressure, the renin–angiotensin system – and the angiotensin-converting enzyme (ACE)– angiotensin (Ang) II–AT1 receptor axis – may play a prominent role to promote inflammation and fibrosis
The discovery of the angiotensin-converting enzyme (ACE) homolog ACE2 [EC 3.4.15.1] has provoked intensive efforts to elucidate the role of this enzyme in various pathologies, including hypertension, diabetes, heart failure, viral infection, pulmonary injury and liver fibrosis
The biological relevance of ACE2 reflects its critical location in the enzymatic cascade of the renin– angiotensin system to directly govern the local expression of angiotensin (Ang) II and Ang-(1–7), two bioactive hormones with significant and opposing actions

Summary

Introduction

Viewed as important in the regulation of blood pressure, the renin–angiotensin system – and the angiotensin-converting enzyme (ACE)– angiotensin (Ang) II–AT1 receptor axis – may play a prominent role to promote inflammation and fibrosis. In the present issue of Arthritis Research & Therapy, Takahashi and colleagues assessed circulating levels of ACE2 in patients with connective tissue pathologies including pulmonary hypertension and persistent digital ACE is considered the primary enzymatic pathway that catalyzes the generation of Ang II in the circulation and tissues.

Results

Conclusion