α‐Tocopherol promotes HaCaT keratinocyte wound repair through the regulation of polarity proteins leading to the polarized cell migration

Abstract

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.

Keratinocytes Migration Promotion, Proliferation Induction, and Free Radical Injury Prevention by 3-Hydroxytirosol

“…In addition to cell proliferation, an adequate cell migration is also required for the second phase of wound healing for minor, superficial, and basic skin lesions, but also for more complicated pathological states such as ulcers or pressure sores [38,39].…”

“…Regulation of epithelial cell migration involves several factors and for this process the activation of cytoskeletal remodeling signaling pathways is essential [38][39][40][41][42][43]. In order to establish the mechanism of HT action on the migration stimulation, we determined the expression of crucial proteins involved in the migration process by western blot.…”

Factorial design-assisted supercritical carbon-dioxide extraction of cytotoxic active principles from Carica papaya leaf juice

“…showed that α-tocopherol (vitamin E) suppressed the growth of murine B16 melanomas in-vitro and in-vivo 27 . It is interesting to note that dl-α-tocopherol stimulated HaCaT wound healing in-vitro and exerted protective properties against skin induced tumorigenesis in mice 28,29 .…”

Stimulatory Effects ofPaederia foetidaFlower Absolute on the Skin Wound and Barrier Repair Activities of Keratinocytes

“…Of these compounds, linolenic acid had the largest peak area (27.97 %) and was followed by tetracosane (–) (8.72 %), 1‐heneicosene (7.69 %), 10‐heneicosene (6.46 %), campesterol (6.35 %), 4‐methyl‐6‐ tert ‐butylphenol (5.77 %), clionasterol (5.60 %), and 1‐tetracosanol (5.15 %; Table 1). Of the 23 identified components in PFFA, hexadecanoic acid, linolenic acid, and vitamin E are reported to promote the migration, proliferation, or skin barrier associated protein formation in many cell types including keratinocytes [29–34] . In addition, cycloartenol, hexadecanoic acid, and vitamin E were implicated in inducing collagen synthesis in cells such as hepatic stellate cells or dermal fibroblasts [29,35–37] .…”

“…Of the 23 identified components in PFFA, hexadecanoic acid, linolenic acid, and vitamin E are reported to promote the migration, proliferation, or skin barrier associated protein formation in many cell types including keratinocytes. [29][30][31][32][33][34] In addition, cycloartenol, hexadecanoic acid, and vitamin E were implicated in inducing collagen synthesis in cells such as hepatic stellate cells or dermal fibroblasts. [29,[35][36][37] Therefore, it can be assumed that PFFA may have the ability to facilitate healing and barrier repair-linked responses in wounded skin.…”