Activation mechanisms and multifaceted effects of mast cells in ischemia reperfusion injury.

Mast cells (MCs) are tissue resident effector cells that form an important part of the immune system's first-line of defence against various pathogenic challenges. They are well known for their roles in anaphylaxis and allergy; however, increasing evidence implicates MCs in a wide range of pathologies. Ischemia/reperfusion (I/R) injury elicits an inflammatory response and triggers the program of tissue damage and restoration, as well as immune regulation. MCs are uniquely distributed around microvasculature and potentially the first responders to early or specific aspects of IR pathogenesis through the release of preformed mediators of MC granule. Versatility and extreme heterogeneity are hallmarks of MCs, resulting from different adaptions acquired during phylogenesis; such plasticity is also highlighted during MC development. Thus, it is necessary to discuss the functions of the MC population that could differ depending on the tissue in which they reside, and various effects of MCs can be induced by stimuli during I/R. In this review, we primarily discuss the contribution of MC activation in I/R injuries of hepatic, pulmonary, myocardial, cerebral, renal, and intestinal organs or systems. A further understanding of the mechanisms underlying the role of MCs in I/R injuries would aid the development of specific MC-targeted therapeutics to protect against some specific injury, such as negating the proinflammatory roles of some specific MC mediators.