Restraint stress and corticotropin releasing hormone modulation of murine cutaneous POMC mRNA.

The skin is a unique immunological defense barrier that protects the organism from occupational and environmental exposures and provides a model system in which to evaluate the interaction of the central nervous system with the peripheral immune response. In the studies presented here, we tested mild, acute restraint stress activation of the cutaneous corticotropin releasing hormone-pro-opiomelanocortin (CRH-POMC) axis. We verified that 2 h restraint stress increased the serum concentration of corticosterone and alpha-melanocyte stimulating hormone. We report for the first time that CRH upregulates POMC mRNA expression in mouse skin in vitro. We also demonstrated, by RT-PCR, that 2,4 di-nitrofluorobenzene (DNFB) upregulates cutaneous POMC mRNA expression, the production of which is suppressed by restraint stress. These data confirm the presence and functionality of two hormones of the hypothalamo-pituitary axis in the skin and suggest that activation of the central hypothalamo-pituitary-adrenal axis may over ride activation of the cutaneous CRH-POMC mechanism in the development of DNFB-stimulated allergic contact dermatitis.