RESUMEN
Reepithelialisation is fundamental to wound healing, but our current understanding largely relies on cellular and animal studies. The aim of the present randomised double-blind three-arm controlled trial was to correlate genuine epidermal wound healing with key proteins and topical zinc treatment in humans. Sixty wounds were produced using deroofed suction blisters in 30 healthy volunteers and randomised to topical zinc sulphate (n = 20), placebo (n = 20), or control (n = 20) treatment for 4 days. All wounds with perilesional skin were processed for automatic immunostaining of paraffin tissue sections with monoclonal antibodies against Ki-67, metallothionein (MT) and matrix metalloproteinase (MMP)-1. Protein expression was quantified by automated digital image analysis. Epidermal Ki-67 and MT labelling indices were increased in keratinocytes in the neoepidermis (â¼1.1 mm) and at the wound edge (0.5 mm) compared to normal skin. Increased MMP-1 immunostaining was restricted to the neoepidermis. MT was robustly upregulated in the upper dermis of the wounds. Zinc treatment enhanced MMP-1 expression beneath the neoepidermis via paracrine mechanisms and MT under the neoepidermis and in the nonepithelialised wound bed via direct actions of zinc as indicated by the induction of MT2A mRNA but not MMP-1 mRNA in cultured normal human dermal fibroblasts by zinc sulphate. The present human study demonstrates that quantitative immunohistochemistry can identify proteins involved in reepithelialisation and actions of external compounds. Increased dermal MT expression may contribute to the anti-inflammatory activities of zinc and increased MMP-1 levels to promote keratinocyte migration.
Asunto(s)
Epidermis/efectos de los fármacos , Antígeno Ki-67/biosíntesis , Metaloproteinasa 1 de la Matriz/biosíntesis , Metalotioneína/biosíntesis , Cicatrización de Heridas/efectos de los fármacos , Sulfato de Zinc/farmacología , Método Doble Ciego , Epidermis/metabolismo , Humanos , Inmunohistoquímica , Antígeno Ki-67/análisis , Metaloproteinasa 1 de la Matriz/análisis , Metalotioneína/análisisRESUMEN
BACKGROUND: The enteroendocrine hormone glucagon-like peptide- (GLP-) 2 is a potent trophic factor in the gastrointestinal tract. The GLP-2 receptor (GLP-2R) is expressed in the stroma of the large bowel wall, which is the major therapeutic target area to prevent anastomotic leakage. We investigated the efficacy of the long-acting GLP-2 analogue ZP1849 on colonic anastomotic wound healing. METHODS: Eighty-seven male Wistar rats were stratified into four groups and received daily treatment with vehicle or ZP1849 starting one day before (day -1) end-to-end anastomosis was constructed in the left colon on day 0, and on days 0 (resected colon segment), 3, and 5, gene expressions of GLP-2R, Ki67, insulin-like growth factor- (IGF-) 1, type I (COL1A1) and type III (COL3A1) procollagens, cyclooxygenase- (COX-) 1, COX-2, and matrix metalloproteinase- (MMP-) 7 were quantified by RT-qPCR. Breaking strength, myeloperoxidase (MPO), transforming growth factor- (TGF-) ß1, and soluble collagen proteins were measured on days 3 and 5. RESULTS: ZP1849 treatment increased Ki67 (P < 0.0001) and IGF-1 (P < 0.05) mRNA levels in noninjured colon day 0, and postoperatively in the anastomotic wounds compared to vehicle-treated rats. ZP1849-treated rats had increased (P = 0.042) anastomotic breaking strength at day 5 compared with vehicle. COL1A1 and COL3A1 mRNA levels (P < 0.0001) and soluble collagen proteins (P < 0.05) increased from day 3 to day 5 in ZP1849-treated rats, but not in vehicle-treated rats. COX-2 mRNA and MPO protein levels decreased from day 3 to day 5 (P < 0.001) in both groups. ZP1849 treatment reduced TGF-ß1 protein levels on day 5 (P < 0.001) but did not impact MMP-7 transcription. CONCLUSIONS: The GLP-2 analogue ZP1849 increased breaking strength, IGF-1 expression, and cell proliferation, which may be beneficial for colonic anastomotic wound healing.