Proteinase‐activated receptors (PARs) and immune function

Abstract

Proteinase-activated receptors (PARs) function as cell sensors for proteinases. Expression of PARs in immune cells suggests a role in innate immunity. PAR 1 mediates the cellular effects of thrombin and causes cytokine and chemokine production by endothelial cells and macrophages. Expression of PAR 1 on fibroblasts mediates the profibrogenic activity of thrombin and triggers extracellular matrix protein deposition. PAR 2 activation by trypsin, tryptase, and coagulation proteinases triggers both pro-and antiinflammatory activities by regulating monocyte recruitment/activation in inflamed tissues. Drug Dev.

Milestones in the Development of Chronic LPS-Induced Airway Disease

“…PAR-1 is expressed normally on bronchial epithelial cells, as well as on inflammatory and interstitial cells following bleomycin instillation [63]. There is some evidence that PAR-1 activation by thrombin is important in the pathogenesis of asthma [64]. PAR-1 protein overexpression in alveolar macrophages is induced by cigarette smoking [65].…”

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“…PARs are widely distributed throughout the human body and involved in many physiological and pathological processes, e. g., PARs play a role in the pathophysiology for atopic and allergic diseases. Activation of PAR-2 triggers both pro-and anti-inflammatory activities by regulating monocyte recruitment/activation in inflamed tissue [83]. So the effects of latex proteases might be discussed within the activation of protease activated receptors.…”