title: Purinergic receptor expression in the regeneration epidermis in a rat model of normal and delayed wound healing.
abstract: This study investigated changes in the protein expression of purinergic receptors in the regenerating rat epidermis during normal wound healing, in denervated wounds, and in denervated wounds treated with nerve growth factor (NGF), where wound healing rates are normalized. Excisional wounds were placed within denervated, pedicled, oblique, groin skin flaps, and in the contralateral abdomen to act as a control site. Six rats had NGF-treated wounds and six had untreated wounds. Tissue was harvested at day four after wounding. The re-epithelializing wound edges were analyzed immunohistochemically for P2X(5), P2X(7), P2Y(1) and P2Y(2) receptors, and immunostaining of keratinocytes was quantified using optical densitometry. In normal rat epidermis, P2Y(1) and P2Y(2) receptors were found in the basal layer where keratinocytes proliferate; P2X(5) receptors were associated with proliferating and differentiating epidermal keratinocytes in basal and suprabasal layers; P2X(7) receptors were associated with terminally differentiated keratinocytes in the stratum corneum. In the regenerating epidermis of denervated wounds, P2Y(1) receptor protein expression was significantly increased in keratinocytes (P<0.001) but P2Y(1) receptors (P<0.001) compared with untreated denervated wounds. In innervated wounds, NGF treatment enhanced expression in keratinocytes. P2X(5) (P>0.001) and P2Y(1) receptor protein (P<0.001) expression in keratinocytes. P2X(7) receptors were absent in all experimental wound healing preparations. P2X(5), P2X(7), P2Y(1) and P2Y(2) receptor protein expression in the regenerating epidermis was altered both during wound healing and also by NGF treatment. Possible roles for purinergic signalling and its relation to NGF in wound healing are discussed.
authors.affiliation: Department of Surgery, Royal Free and University College Medical School, Royal Free Campus, London.
authors.forename: Aina V H
authors.initials: AV
authors.lastname: Greig
authors.forename: Stuart E
authors.initials: SE
authors.lastname: James
authors.forename: D Angus
authors.initials: DA
authors.lastname: McGrouther
authors.forename: Giorgio
authors.initials: G
authors.lastname: Terenghi
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Burnstock
mesh_terms: D000818:Animals; D002455:Cell Division; D003720:Densitometry; D004817:Epidermis / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D020932:Nerve Growth Factor / Q000378:metabolism; D009414:Nerve Growth Factors; D010641:Phenotype; D051381:Rats; D011983:Receptors, Purinergic / Q000096:biosynthesis*; D018048:Receptors, Purinergic P2 / Q000096:biosynthesis / Q000378:metabolism; D058485:Receptors, Purinergic P2X5; D058486:Receptors, Purinergic P2X7; D058472:Receptors, Purinergic P2Y1; D058473:Receptors, Purinergic P2Y2; D012038:Regeneration; D012867:Skin / Q000473:pathology; D013997:Time Factors; D014945:Wound Healing
chemical_list: D009414:Nerve Growth Factors; C546467:P2rx5 protein, rat; C546470:P2rx7 protein, rat; C546384:P2ry1 protein, rat; C546387:P2ry2 protein, rat; D011983:Receptors, Purinergic; D018048:Receptors, Purinergic P2; D058485:Receptors, Purinergic P2X5; D058486:Receptors, Purinergic P2X7; D058472:Receptors, Purinergic P2Y1; D058473:Receptors, Purinergic P2Y2; D020932:Nerve Growth Factor