Resolution of Inflammation

Abstract

Brief overview: Acute inflammation is a protective response to invading microbes and tissue injury, and resolution is necessary for tissues to return to their normal state after the benefits of acute inflammation have been achieved. The resolution process is important for prevention of diseases characterized by chronic inflammation and tissue injury, such as atherosclerosis, cancer, inflammatory arthritis, and inflammatory bowel disease. Resolution of inflammation is the coordinated, active termination of an inflammatory response. The term encompasses a switch in enzymatic activity and the biological actions of subsequently produced pro-resolving mediators, as well as the apoptosis and clearance of inflammatory cells (reviewed in Serhan 2007; Serhan et al. 2008). The process is typified by (1) the production of distinct lipid mediator classes: eicosanoids, resolvins, protectins, maresins, and anti-inflammatory cytokines; and (2) an active switch in cell types within the site of inflammation. Pro-resolution mediators signal termination of an inflammatory response by reducing neutrophil infiltration, activating neutrophil apoptosis, and recruitment of monocytes that mature into macrophages which clear apoptotic neutrophils and inflammatory debris. This process allows the tissue to return to homeostasis, a process also referred to as catabasis.