MRGPRX2

MRGPRX2 (Mas-related G-protein coupled receptor X2) is a human gene encoding a G protein-coupled receptor (GPCR). It is primarily expressed in mast cells, but may also be found in other immune cells and sensory neurons.

The MRGPRX2 receptor is activated by a variety of ligands, including neuropeptides (e.g., substance P), host defense peptides (e.g., LL-37), basic secretagogues (e.g., compound 48/80), and certain drugs, particularly neuromuscular blocking agents (e.g., rocuronium) and fluoroquinolone antibiotics. Upon activation, MRGPRX2 triggers mast cell degranulation, leading to the release of histamine, tryptase, and other inflammatory mediators. This degranulation process can contribute to various physiological and pathological conditions.

Clinically, MRGPRX2 activation is implicated in pseudo-allergic drug reactions, also known as non-immunoglobulin E (IgE)-mediated hypersensitivity reactions. These reactions can mimic IgE-mediated allergies but do not involve IgE antibodies. Activation of MRGPRX2 by drugs can cause symptoms such as flushing, urticaria, angioedema, hypotension, and bronchospasm. The severity of these reactions can vary from mild to life-threatening.

Research into MRGPRX2 aims to develop novel therapeutic strategies to prevent or treat MRGPRX2-mediated pseudo-allergic reactions and to explore its role in other inflammatory diseases. Understanding the mechanisms of MRGPRX2 activation and its downstream signaling pathways is crucial for the development of targeted therapies.