Galanin contributes to ultraviolet irradiation‐induced inflammation in human skin

Exposure of the skin to ultraviolet (UV) irradiation causes various consequences such as inflammation and photoageing. Galanin is an active neuropeptide expressed widely in the central nervous system and peripheral tissues including the skin. Galanin promotes or inhibits inflammation in a context‐dependent manner, but its role in UV irradiation‐induced responses in human skin was still unknown. UV irradiation induced a substantial expression of galanin in primary epidermal keratinocytes in vitro and in human epidermis in vivo. Galanin knock‐down by siRNA transfection markedly inhibited UV irradiation‐induced expression of matrix metalloproteinase (MMP)‐1, interleukin (IL)‐1β, IL‐6 and cyclooxygenase (COX)‐2. Moreover, siRNA‐mediated knock‐down of GAL2, a principal galanin receptor in the skin, led to a considerable decrease in these mediators in keratinocytes. Collectively, our findings suggest that galanin is an important messenger between the neuroendocrine system and UV irradiation‐damaged skin.

[1]  J. McDougall,et al.  Galanin 3 receptor‐deficient mice show no alteration in the oxazolone‐induced contact dermatitis phenotype , 2016, Experimental dermatology.

[2]  Hiroshi Tanaka,et al.  Morphological change of skin fibroblasts induced by UV Irradiation is involved in photoaging , 2016, Experimental dermatology.

[3]  S. Amano.  Characterization and mechanisms of photoageing‐related changes in skin. Damages of basement membrane and dermal structures , 2016, Experimental dermatology.

[4]  Dong Hun Lee,et al.  Serum amyloid A1 secreted from UV‐irradiated keratinocytes induces matrix metalloproteinase‐1 in fibroblasts through toll‐like receptor 4 , 2016, Experimental dermatology.

[5]  C. Kang,et al.  Inhibition of hedgehog signalling attenuates UVB‐induced skin photoageing , 2015, Experimental dermatology.

[6]  D. Orioli,et al.  Reference genes for gene expression analysis in proliferating and differentiating human keratinocytes , 2015, Experimental dermatology.

[7]  Z. Upton,et al.  Insulin‐like growth factor‐I and UVB photoprotection in human keratinocytes , 2015, Experimental dermatology.

[8]  T. Hökfelt,et al.  Physiology, Signaling, and Pharmacology of Galanin Peptides and Receptors: Three Decades of Emerging Diversity , 2015, Pharmacological Reviews.

[9]  J. Chung,et al.  Atomic Hydrogen Surrounded by Water Molecules, H(H2O)m, Modulates Basal and UV-Induced Gene Expressions in Human Skin In Vivo , 2013, PloS one.

[10]  B. Kofler,et al.  The galanin peptide family in inflammation , 2011, Neuropeptides.

[11]  Wei Xia,et al.  Matrix-degrading metalloproteinases in photoaging. , 2009, The journal of investigative dermatology. Symposium proceedings.

[12]  B. Kofler,et al.  Targeted Disruption of the Galanin Gene Attenuates Inflammatory Responses in Murine Skin , 2008, Journal of Molecular Neuroscience.

[13]  B. Kofler,et al.  The galanin peptide family: receptor pharmacology, pleiotropic biological actions, and implications in health and disease. , 2007, Pharmacology & therapeutics.

[14]  L. Kemény,et al.  Galanin receptor expression in cultured human keratinocytes and in normal human skin , 2006, Journal of the peripheral nervous system : JPNS.

[15]  T. Hökfelt,et al.  Generation and phenotypic characterization of a galanin overexpressing mouse , 2005, Neuroscience.