Gene expression profiling defines the role of ATP-exposed keratinocytes in skin inflammation

• Published in: Journal of dermatological science 2010-05, Vol.58 (2), p.143-151
• Main Authors: Ohara, Hiroshi, Saito, Rumiko, Hirakawa, Satoshi, Shimada, Miki, Mano, Nariyasu, Okuyama, Ryuhei, Aiba, Setsuya
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - chemistry; Adenosine Triphosphate - metabolism; Blotting, Western; Dermatology; Enzyme-Linked Immunosorbent Assay - methods; Gene Expression Profiling; Humans; Inflammation; Interleukin-6 - metabolism; Interleukins - metabolism; Keratinocytes - cytology; Oligonucleotide Array Sequence Analysis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Skin - cytology; STAT3 Transcription Factor - metabolism
• ISSN: 0923-1811; 1873-569X
• DOI: 10.1016/j.jdermsci.2010.02.007

Abstract Background Various environmental stimuli, e.g., mechanical stress, osmolarity change, oxidative stress, and microbial products trigger ATP release from cells. It is well known that ATP regulates cell growth, differentiation, terminal differentiation, and cell-to-cell communication in keratinocytes. Moreover, extracellular ATP stimulates the expression and release of IL-6 and modulates the production several chemokines by keratinocytes. Objective To investigate the role of ATP-stimulated keratinocytes in skin inflammation and immune response. Methods We identified genes whose expression is augmented in ATP-stimulated human keratinocytes by DNA microarray. These microarray data were validated by quantitative real-time RT-PCR. Furthermore, we confirmed the observed mRNA change at protein level by ELISA and Western blotting. Results The statistical analysis of the microarray data revealed that, besides IL-6, the expression of several novel genes such as IL-20, CXCL1-3, and ATF3 was significantly augmented in ATP-stimulated keratinocytes. These data was validated by quantitative real-time RT-PCR. We also confirmed the augmented production of IL-6, IL-20, CXCL1 by ELISA and that of ATF3 by Western blotting. Since both IL-6 and IL-20 that can stimulate STAT3 were produced by the ATP-stimulated keratinocytes, we examined their phosphorylation of STAT3. The study demonstrated biphasic activation of STAT3 after ATP stimulation, which was composed of a first peak at 1–2 h and a second peak at 12–24 h. The latter peak was significantly suppressed by anti-IL-6 antibody. Conclusion These studies characterized (1) STAT3 activation, (2) chemotaxis for neutrophils via CXCL1-3, and (3) ATF3 activation as possible roles of ATP-stimulated keratinocytes in skin inflammation and immune response.