α-Tocopherol promotes HaCaT keratinocyte wound repair through the regulation of polarity proteins leading to the polarized cell migration.
In many developed countries including Japan, how to care the bedridden elderly people with chronic wounds such as decubitus becomes one of the most concerned issues. Although antioxidant micronutrients including vitamin E, especially α-tocopherol (α-Toc), are reported to shorten a period of wound closure, the promoting effect of α-Toc on wound healing independent of its antioxidant activity remains to be fully elucidated. The aim of this study was to examine whether α-Toc affects wound-mediated HaCaT keratinocyte polarization process including the recruitment of polarity regulating proteins, leading to wound repair independently of its antioxidant activity. We investigated the effects of α-Toc and other antioxidants such as Trolox, a cell-permeable α-Toc analog on the migration, proliferation, and cell polarization of HaCaT keratinocytes after wounding. We analyzed the localization and complex formation of polarity proteins, partitioning defective 3 (Par3), and atypical protein kinase C (aPKC), and aPKC activity by immunohistochemistry, immunoprecipitation analyses, and in vitro kinase assays, respectively. α-Toc but not other antioxidants enhanced the wound closure and cell polarization in HaCaT keratinocytes after wounding. α-Toc regulated the localization and complex formation of Par3 and aPKC during wound healing. Knockdown of aPKC or Par3 abrogated α-Toc-mediated promotion of the wound closure and cell polarization in HaCaT keratinocytes. Furthermore, aPKC kinase activity was significantly increased in α-Toc-treated cells through activation of phosphatidylinositol 3-kinase/Akt signaling pathway. These results suggest that α-Toc promotes HaCaT keratinocyte wound repair by regulating the aPKC kinase activity and the formation of aPKC-Par3 complex. © 2017 BioFactors, 44(2):180-191, 2018.
['Horikoshi|Yosuke|Y|http://orcid.org/0000-0001-6587-644X', 'Kamizaki|Kouki|K|', 'Hanaki|Takehiko|T|', 'Morimoto|Masaki|M|', 'Kitagawa|Yoshinori|Y|', 'Nakaso|Kazuhiro|K|', 'Kusumoto|Chiaki|C|', 'Matsura|Tatsuya|T|']
D048868:Adaptor Proteins, Signal Transducing D018797:Cell Cycle Proteins D002461:Cell Line, Transformed D002465:Cell Movement D016764:Cell Polarity D049109:Cell Proliferation D002839:Chromans D005786:Gene Expression Regulation D006801:Humans D015603:Keratinocytes D008565:Membrane Proteins D008954:Models, Biological D058539:Phosphatidylinositol 3-Kinase D011493:Protein Kinase C D051057:Proto-Oncogene Proteins c-akt D015398:Signal Transduction D014945:Wound Healing D024502:alpha-Tocopherol
HaCaT Vitamin E wound healing cell polarity Par3 aPKC