Itch Mechanisms

Xinzhong Dong, Johns Hopkins University

Itch, also known as pruritus, is defined as an “unpleasant skin sensation that elicits the desire or reflex to scratch”. Chronic itch conditions, such as those arising from atopic dermatitis, psoriasis, renal and liver diseases, drug treatment, significantly affects the quality of the patients’ lives. Primary sensory neurons in dorsal root ganglia (DRG) play an essential role in generating itch by detecting itch stimuli through their peripheral axons in the skin and sending signals to the spinal cord via their central axons. We identified a large family of G protein‐coupled receptors in mice called Mrgprs. Many of these receptors are exclusively expressed in distinct subsets of DRG neurons. We found that several Mrgprs function as novel receptors by directly sensing variety of itchy substances including peptides, drugs, amino acids, and proteases. Importantly, the mouse works have been confirmed by human psychophysical studies. In addition, we have genetically labeled and manipulated Mrgpr‐expressing neurons in DRG and demonstrated for the first time that there is a labeled line in DRG for itch coding. Therefore, we believe that targeting Mrgprs may lead to novel treatment of chronic itch in the future.

November 21st, 2013 at 3:15 PM in the Clark Center Auditorium

Hosted by:

Michael Lin, Assistant Professor, Department of Pediatrics, Stanford University

Pre-Seminar November 18th, 2013 at 3:15 PM in Clark S361