Hydroquinone Induced Skin Irritant Reaction Could Be Achieved by Activating Mast Cells via Mas-related G protein-coupled receptor X2.

BACKGROUND
Hydroquinone (HQ), is one of the most effective drugs to treat hyperpigmentary disorders, but often causes skin irritation in clinic. Mast cell plays an important role in contact dermatitis and triggering pseudo-allergic reactions via MRGPRX2. Whether HQ induced skin irritant reaction through activating mast cells via MRGPRX2 remains unknown.


OBJECTIVES
To investigate the role of mast cells in HQ induced skin irritant reaction and verify whether MRGPRX2 participated in the HQ effect on mast cells which contributed to the pathogenesis of skin irritant reaction.


METHODS
A mouse model of HQ induced skin irritation was established to observe the local and systemic inflammation associated with mast cell receptor MrgprB2. Human mast cell LAD2 were used to verify the effect of HQ on mast cells via MRGPRX2 by knocking down with siRNA.


RESULTS
Mast cells were involved in the development of HQ-induced irritant reaction and local inflammation are closely related to mast cell receptor MrgprB2. HQ could activate mast cells via MRGPRX2, causing changes in calcium concentration, degranulation, and release of inflammatory cytokines which lead to skin irritant reaction.


CONCLUSIONS
HQ induced skin irritant reaction could be skin pseudo-allergic reactions achieved by activating mast cells via MRGPRX2.