Inhibition of IRF8 Negatively Regulates Macrophage Function and Impairs Cutaneous Wound Healing
- 645 Downloads
The inflammatory response is essential for normal cutaneous wound healing. Macrophages, as critical inflammatory cells, coordinate inflammation and angiogenesis phases during wound healing. It has been reported that the transcription factor interferon regulatory factor 8 (IRF8), a member of the IRF family, plays a critical role in the development and function of macrophages and is associated with inflammation. However, the role of IRF8 in cutaneous wound healing and its underlying mechanism remain elusive. Through immunohistochemical (IHC) staining, we showed that IRF8 is involved in the wound repair process in mice and patients. Furthermore, we ascertain that the repression of IRF8 by small interfering RNA (siRNA) leads to delayed wound healing. To explore the mechanism by which IRF8 impacts wound healing, we observed its effect on macrophage-related mediators by IHC or real-time PCR. The results demonstrated that the inhibition of IRF8 decreases the mRNA expression of inflammatory mediators associated with M1 macrophage (il-1b, il-6, inos, and tnf-a) but no impact on M2 macrophage-related mediators (arg-1, mrc-1, and il-10) and the number of macrophages in the wounds. Furthermore, the inhibition of IRF8 induced apoptosis in the wounds. In summary, this study demonstrates that the down-regulation of IRF8 in the wound leads to impaired wound healing possibly through the regulation of macrophage function and apoptosis in skin wound.
KEY WORDSIRF8 wound healing macrophage inflammation
This work was supported partially by the National Natural Science Foundation of China (Nos. 81272113 and 81201469).
Compliance with Ethical Standards
This study was approved by the Ethics Committee of the Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine (2013-022). Preoperative informed consent was obtained from each patient registered in this study in accordance with the institutional guidelines.
Conflict of Interest
The authors declare that they have no conflicts of interest.
- 3.Morris Jr., M.W., M. Allukian 3rd, B.J. Herdrich, R.C. Caskey, C. Zgheib, J. Xu, W. Dorsett-Martin, M.E. Mitchell, and K.W. Liechty. 2014. Modulation of the inflammatory response by increasing fetal wound size or interleukin-10 overexpression determines wound phenotype and scar formation. Wound Repair and Regeneration 22(3): 406–414.CrossRefPubMedGoogle Scholar
- 9.Zhang, Q.Z., W.R. Su, S.H. Shi, P. Wilder-Smith, A.P. Xiang, A. Wong, A.L. Nguyen, C.W. Kwon, and A.D. Le. 2010. Human gingiva-derived mesenchymal stem cells elicit polarization of M2 macrophages and enhance cutaneous wound healing. Stem Cells 28(10): 1856–1868.CrossRefPubMedPubMedCentralGoogle Scholar
- 10.Dror, N., M. Alter-Koltunoff, A. Azriel, N. Amariglio, J. Jacob-Hirsch, S. Zeligson, A. Morgenstern, T. Tamura, H. Hauser, G. Rechavi, K. Ozato, and B.Z. Levi. 2007. Identification of IRF-8 and IRF-1 target genes in activated macrophages. Molecular Immunology 44(4): 338–346.CrossRefPubMedGoogle Scholar
- 15.Paschall, A.V., R. Zhang, C.F. Qi, K. Bardhan, L. Peng, G. Lu, J. Yang, M. Merad, T. McGaha, G. Zhou, A. Mellor, S.I. Abrams, H.C. Morse 3rd, K. Ozato, H. Xiong, and K. Liu. 2015. IFN regulatory factor 8 represses GM-CSF expression in T cells to affect myeloid cell lineage differentiation. Journal of Immunology 194(5): 2369–2379.CrossRefGoogle Scholar
- 17.Kurotaki, D., M. Yamamoto, A. Nishiyama, K. Uno, T. Ban, M. Ichino, H. Sasaki, S. Matsunaga, M. Yoshinari, A. Ryo, M. Nakazawa, K. Ozato, and T. Tamura. 2014. IRF8 inhibits C/EBPalpha activity to restrain mononuclear phagocyte progenitors from differentiating into neutrophils. Nature Communications 5: 4978.CrossRefPubMedGoogle Scholar
- 18.Sasaki, H., D. Kurotaki, N. Osato, H. Sato, I. Sasaki, S. Koizumi, H. Wang, C. Kaneda, A. Nishiyama, T. Kaisho, H. Aburatani, H.C. Morse 3rd, K. Ozato, and T. Tamura. 2015. Transcription factor IRF8 plays a critical role in the development of murine basophils and mast cells. Blood 125(2): 358–369.CrossRefPubMedPubMedCentralGoogle Scholar
- 19.Watanabe, T., C. Hotta, S. Koizumi, K. Miyashita, J. Nakabayashi, D. Kurotaki, G.R. Sato, M. Yamamoto, M. Nakazawa, H. Fujita, R. Sakai, S. Fujisawa, A. Nishiyama, Z. Ikezawa, M. Aihara, Y. Ishigatsubo, and T. Tamura. 2013. The transcription factor IRF8 counteracts BCR-ABL to rescue dendritic cell development in chronic myelogenous leukemia. Cancer Research 73(22): 6642–6653.CrossRefPubMedGoogle Scholar
- 20.Szelag, M., Piaszyk-Borychowska, A., Plens-Galaska, M., Wesoly, J., and Bluyssen, H.A. 2016. Targeted inhibition of STATs and IRFs as a potential treatment strategy in cardiovascular disease. Oncotarget. doi: 10.18632/oncotarget.9195.
- 21.Chmielewski, S., A. Piaszyk-Borychowska, J. Wesoly, and H.A. Bluyssen. 2015. STAT1 and IRF8 in vascular inflammation and cardiovascular disease: Diagnostic and therapeutic potential. International Reviews of Immunology 25: 1–21.Google Scholar
- 22.Yan, M., H. Wang, J. Sun, W. Liao, P. Li, Y. Zhu, C. Xu, J. Joo, Y. Sun, S. Abbasi, A. Kovalchuk, N. Lv, W.J. Leonard, and H.C. Morse. 2016. Cutting edge: Expression of IRF8 in gastric epithelial cells confers protective innate immunity against Helicobacter pylori infection. Journal of Immunology 196(5): 1999–2003.CrossRefGoogle Scholar
- 23.Luda, K.M., T. Joeris, E.K. Persson, A. Rivollier, M. Demiri, K.M. Sitnik, L. Pool, J.B. Holm, F. Melo-Gonzalez, L. Richter, B.N. Lambrecht, K. Kristiansen, M.A. Travis, M. Svensson-Frej, K. Kotarsky, and W.W. Agace. 2016. IRF8 transcription-factor-dependent classical dendritic cells are essential for intestinal T cell homeostasis. Immunity 44(4): 860–874.CrossRefPubMedGoogle Scholar
- 24.Yoshida, Y., R. Yoshimi, H. Yoshii, D. Kim, A. Dey, H. Xiong, J. Munasinghe, I. Yazawa, M.J. O’Donovan, O.A. Maximova, S. Sharma, J. Zhu, H. Wang, H.C. Morse 3rd, and K. Ozato. 2014. The transcription factor IRF8 activates integrin-mediated TGF-beta signaling and promotes neuroinflammation. Immunity 40(2): 187–198.CrossRefPubMedPubMedCentralGoogle Scholar
- 32.Hu, X., D. Yang, M. Zimmerman, F. Liu, J. Yang, S. Kannan, A. Burchert, Z. Szulc, A. Bielawska, K. Ozato, K. Bhalla, and K. Liu. 2011. IRF8 regulates acid ceramidase expression to mediate apoptosis and suppresses myelogeneous leukemia. Cancer Research 71(8): 2882–2891.CrossRefPubMedPubMedCentralGoogle Scholar