Leukotriënsignalering

Leukotriënsignalering is a crucial biological process involving a group of lipid mediators called leukotrienes. These molecules are synthesized from arachidonic acid through the action of lipoxygenases. Leukotrienes play significant roles in inflammatory responses, particularly in allergic reactions and asthma.

The signaling pathway begins when a cell, such as a mast cell or eosinophil, is stimulated by an antigen or other inflammatory triggers. This stimulation activates enzymes that convert arachidonic acid into leukotrienes. The primary leukotrienes involved in signaling are the cysteinyl leukotrienes, including LTC4, LTD4, and LTE4.

Once synthesized, these leukotrienes are released into the extracellular space. They then bind to specific G protein-coupled receptors on target cells, such as smooth muscle cells, eosinophils, and endothelial cells. This binding initiates a cascade of intracellular events. For instance, in airway smooth muscle, leukotriene binding leads to muscle contraction, causing bronchoconstriction, a hallmark of asthma. In eosinophils, leukotrienes promote their migration to sites of inflammation, activation, and degranulation, further amplifying the inflammatory response.

The leukotriene signaling pathway contributes to various pathological conditions. Beyond asthma, it is implicated in inflammatory bowel disease, psoriasis, and certain cardiovascular diseases. Consequently, drugs that block leukotriene synthesis or receptor activity, such as leukotriene receptor antagonists and 5-lipoxygenase inhibitors, are used therapeutically to manage inflammatory conditions. Understanding leukotriënsignalering is vital for developing effective treatments for a range of immune-mediated diseases.