Wnt signaling pathway is a complex protein interaction network, and its function can most commonly or often be seen in embryonic development and cancer treatments, and meanwhile it is also involved in normal physiological processes in adult animals. Recently, with the rapid development of skin tissue engineering, there have been more and more researches on signal pathway in skin wound healing. At present, it is known that Wnt signaling pathway plays a vital role in the epidermal stem cells, epidermal growth factors, hair follicle development and other important factors related to the epidermal repair. The systemic research on Wnt signaling pathway has important clinical significance in the demonstration and functional process of the skin tissue. In this paper, we review the research development of the Wnt signaling pathway in the epidermal repair process.
Epidermal Growth Factor ; metabolism ; Epidermis ; cytology ; injuries ; Humans ; Stem Cells ; cytology ; Wnt Signaling Pathway ; physiology ; Wound Healing ; physiology

This study was conducted to identify the effectiveness of platelet-rich plasma (PRP) and efficacy of intralesional injection as a method of application to acute cutaneous wounds in dogs. Healthy adult beagles (n = 3) were used in this study. Autologous PRP was separated from anticoagulant treated whole blood in three dogs. Cutaneous wounds were created and then treated by intralesional injection of PRP in the experimental group, while they were treated with saline in the control group on days 0, 2 and 4. The healing process was evaluated by gross examination throughout the experimental period and histologic examination on day 7, 14 and 21. In PRP treated wounds, the mean diameter was smaller and the wound closure rate was higher than in the control. Histological study revealed that PRP treated wounds showed more granulation formation and angiogenesis on day 7, and faster epithelialization, more granulation formation and collagen deposition were observed on day 14 than in control wounds. On day 21, collagen deposition and epithelialization were enhanced in PRP treated groups. Overall, PRP application showed beneficial effects in wound healing, and intralesional injection was useful for application of PRP and could be a good therapeutic option for wound management in dogs.
Animals ; Collagen/metabolism ; Dermis/cytology/injuries/physiology ; Dogs ; Epidermis/cytology/injuries/*physiology ; Female ; Granulation Tissue/cytology ; Injections, Intralesional/veterinary ; Male ; Neovascularization, Physiologic ; *Platelet-Rich Plasma ; Regeneration ; Treatment Outcome ; *Wound Healing ; Wounds and Injuries/therapy/*veterinary

OBJECTIVETo isolate and culture the murine fetal epidermal stem cells (ESCs) and folliculus pili cells (FPCs) in vitro, and to observe the regeneration of hair follicle and epidermis after cografting of ESCs and FPCs.

METHODSThe ESCs were isolated by adhering to murine type IV collagen and were cultured in conditional medium. The expression level of beta1-integrin and keratin 15 in ESCs was detected. At the same time, the cell cycle and clony forming eficiency (CFE) in ESCs were also determined. The FPCs were isolated and cultured and inoculated in fibrin-gel to form FPCs-gel. A full skin equivalent was prepared by combining ESCs with FPCs-gel and was grafted onto total skin loss wounds on the back of BALB/C nude mice. The histological changes of the wounds and the hair follicles were observed at 8 - 10 weeks after the grafting.

RESULTSThere were high level expressions of beta1-integrin and keratin 15 in murine fetal ESCs. It was indicated by cell cycle analysis that cells in G1 stage accounted for 94.9% of the cells, while that in S stage, 3.5%, suggesting slow cell cycle. Nevertheless, the keratinocytes in G1 stage accounted for 74.1% and that in S stage, 17.5% of cells in control group. The CFE of ESCs was 15.3%, and it was much higher than that in control group (6.7%). The newly formed hair follicles could be found in the grafted rats but not in the control group 8 - 10 weeks after the wound healing in nude rats.

CONCLUSIONThe ESCs could be successfully isolated and cultured in vitro and might participate in the formation of hair follicle structure under the induction of FPCs.

Animals ; Cells, Cultured ; Dermatologic Surgical Procedures ; Epidermis ; Fetus ; Hair Follicle ; cytology ; physiology ; Immunohistochemistry ; Integrin beta1 ; analysis ; Keratin-15 ; Keratins ; analysis ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Regeneration ; Skin ; injuries ; Skin Transplantation ; methods ; Skin, Artificial ; Stem Cells ; chemistry ; cytology ; Wound Healing