Photo-Oxidation Products of Skin Surface Squalene Mediate Metabolic and Inflammatory Responses to Solar UV in Human Keratinocytes

Vladimir Kostyuk, Alla Potapovich, Andrea Stancato, Chiara de Luca, Daniela Lulli, Saveria Pastore, Liudmila Korkina

Research output: Contribution to journalArticle

Abstract

The study aimed to identify endogenous lipid mediators of metabolic and inflammatory responses of human keratinocytes to solar UV irradiation. Physiologically relevant doses of solar simulated UVA+UVB were applied to human skin surface lipids (SSL) or to primary cultures of normal human epidermal keratinocytes (NHEK). The decay of photo-sensitive lipid-soluble components, alpha-tocopherol, squalene (Sq), and cholesterol in SSL was analysed and products of squalene photo-oxidation (SqPx) were quantitatively isolated from irradiated SSL. When administered directly to NHEK, low-dose solar UVA+UVB induced time-dependent inflammatory and metabolic responses. To mimic UVA+UVB action, NHEK were exposed to intact or photo-oxidised SSL, Sq or SqPx, 4-hydroxy-2-nonenal (4-HNE), and the product of tryptophan photo-oxidation 6-formylindolo[3,2-b]carbazole (FICZ). FICZ activated exclusively metabolic responses characteristic for UV, i.e. the aryl hydrocarbon receptor (AhR) machinery and downstream CYP1A1/CYP1B1 gene expression, while 4-HNE slightly stimulated inflammatory UV markers IL-6, COX-2, and iNOS genes. On contrast, SqPx induced the majority of metabolic and inflammatory responses characteristic for UVA+UVB, acting via AhR, EGFR, and G-protein-coupled arachidonic acid receptor (G2A). Conclusions/Significance: Our findings indicate that Sq could be a primary sensor of solar UV irradiation in human SSL, and products of its photo-oxidation mediate/induce metabolic and inflammatory responses of keratinocytes to UVA+UVB, which could be relevant for skin inflammation in the sun-exposed oily skin.

Original languageEnglish
Article numbere44472
JournalPLoS One
Volume7
Issue number8
DOIs
Publication statusPublished - Aug 30 2012

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Fingerprint Dive into the research topics of 'Photo-Oxidation Products of Skin Surface Squalene Mediate Metabolic and Inflammatory Responses to Solar UV in Human Keratinocytes'. Together they form a unique fingerprint.

Cite this