TY - JOUR T1 - Neurturin Overexpression in Skin Enhances Expression of TRPM8 in Cutaneous Sensory Neurons and Leads to Behavioral Sensitivity to Cool and Menthol JF - The Journal of Neuroscience JO - J. Neurosci. SP - 2060 LP - 2070 DO - 10.1523/JNEUROSCI.4012-12.2013 VL - 33 IS - 5 AU - Ting Wang AU - Xiaotang Jing AU - Jennifer J. DeBerry AU - Erica S. Schwartz AU - Derek C. Molliver AU - Kathryn M. Albers AU - Brian M. Davis Y1 - 2013/01/30 UR - http://www.jneurosci.org/content/33/5/2060.abstract N2 - Neurturin (NRTN) is a member of the glial cell line-derived neurotrophic factor family of ligands that exerts its actions via Ret tyrosine kinase and GFRα2. Expression of the Ret–GFRα2 coreceptor complex is primarily restricted to the peripheral nervous system and is selectively expressed by sensory neurons that bind the isolectin B4 (IB4). To determine how target-derived NRTN affects sensory neuron properties, transgenic mice that overexpress NRTN in keratinocytes (NRTN-OE mice) were analyzed. Overexpression of NRTN increased the density of PGP9.5-positive, but not calcitonin gene-related peptide-positive, free nerve endings in footpad epidermis. GFRα2-immunopositive somata were hypertrophied in NRTN-OE mice. Electron microscopic analysis further revealed hypertrophy of unmyelinated sensory axons and a subset of myelinated axons. Overexpression of NRTN increased the relative level of mRNAs encoding GFRα2 and Ret, the ATP receptor P2X3 (found in IB4-positive, GFRα2-expressing sensory neurons), the acid-sensing ion channel 2a, and transient receptor potential cation channel subfamily member M8 (TRPM8) in sensory ganglia. Behavioral testing of NRTN-OE mice revealed an increased sensitivity to mechanical stimuli in glabrous skin of the hindpaw. NRTN-OE mice also displayed increased behavioral sensitivity to cool temperature (17°C-20°C) and oral sensitivity to menthol. The increase in cool and menthol sensitivity correlated with a significant increase in TRPM8 expression and the percentage of menthol-responsive cutaneous sensory neurons. These data indicate that the expression level of NRTN in the skin modulates gene expression in cutaneous sensory afferents and behavioral sensitivity to thermal, chemical, and mechanical stimuli. ER -