title: UVB Activates Hypothalamic-Pituitary-Adrenal Axis in C57BL/6 Mice.
abstract: To test the hypothesis that UVB can activate the hypothalamic-pituitary-adrenal (HPA) axis, the shaved back skin of C57BL/6 mice was exposed to 400 mJ cm(-2) of UVB or was sham irradiated. After 12 and 24 hours of exposure, plasma, skin, brain, and adrenals were collected and processed to measure corticotropin-releasing hormone (CRH), urocortin (Ucn), β-endorphin (β-END), ACTH, and corticosterone (CORT) or the brain was fixed for immunohistochemical detection of CRH. UVB stimulated plasma levels of CRH, Ucn, β-END, ACTH, and CORT and increased skin expression of Ucn, β-END, and CORT at the gene and protein/peptide levels. UVB stimulated CRH gene and protein expression in the brain that was localized to the paraventricular nucleus of the hypothalamus. In adrenal glands, it increased mRNAs of melanocortin receptor type 2, steroidogenic acute regulatory protein (StAR), and gene coding of steroid 11β-hydroxylase (CYP11B1). Hypophysectomy abolished UVB stimulation of plasma, but not of skin CORT levels, and had no effect on UVB stimulation of CRH and Ucn levels in the plasma, demonstrating the requirement of an intact pituitary for the systemic effect. In conclusion, we identify mechanisms regulating body homeostasis by UVB through activation of the HPA axis that originate in the skin and require the pituitary for systemic effects.
authors.affiliation: Department of Pathology and Laboratory Medicine, Center for Cancer Research, University of Tennessee Health Science Center (UTHSC), Memphis, Tennessee, USA.
authors.forename: Cezary
authors.initials: C
authors.lastname: Skobowiat
authors.affiliation: Department of Pathology and Laboratory Medicine, Center for Cancer Research, University of Tennessee Health Science Center (UTHSC), Memphis, Tennessee, USA; Division of Rheumatology, Department of Medicine, University of Tennessee Health Science Center (UTHSC), Memphis, Tennessee, USA. Electronic address: aslominski@uthsc.edu.
authors.forename: Andrzej T
authors.initials: AT
authors.lastname: Slominski
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism; D003345:Corticosterone / Q000378:metabolism; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D007030:Hypothalamo-Hypophyseal System / Q000528:radiation effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D010902:Pituitary Gland / Q000378:metabolism; D010913:Pituitary-Adrenal System / Q000528:radiation effects*; D012333:RNA, Messenger / Q000378:metabolism; D012867:Skin / Q000528:radiation effects*; D013252:Steroid 11-beta-Hydroxylase / Q000378:metabolism; D014466:Ultraviolet Rays; D054832:Urocortins / Q000378:metabolism; D001615:beta-Endorphin / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D054832:Urocortins; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D013252:Steroid 11-beta-Hydroxylase; D003345:Corticosterone