title: Hypoxia-induced changes in Ca(2+) mobilization and protein phosphorylation implicated in impaired wound healing.
abstract: The process of wound healing must be tightly regulated to achieve successful restoration of injured tissue. Previously, we demonstrated that when corneal epithelium is injured, nucleotides and neuronal factors are released to the extracellular milieu, generating a Ca(2+) wave from the origin of the wound to neighboring cells. In the present study we sought to determine how the communication between epithelial cells in the presence or absence of neuronal wound media is affected by hypoxia. A signal-sorting algorithm was developed to determine the dynamics of Ca(2+) signaling between neuronal and epithelial cells. The cross talk between activated corneal epithelial cells in response to neuronal wound media demonstrated that injury-induced Ca(2+) dynamic patterns were altered in response to decreased O2 levels. These alterations were associated with an overall decrease in ATP and changes in purinergic receptor-mediated Ca(2+) mobilization and localization of N-methyl-d-aspartate receptors. In addition, we used the cornea in an organ culture wound model to examine how hypoxia impedes reepithelialization after injury. There was a change in the recruitment of paxillin to the cell membrane and deposition of fibronectin along the basal lamina, both factors in cell migration. Our results provide evidence that complex Ca(2+)-mediated signaling occurs between sensory neurons and epithelial cells after injury and is critical to wound healing. Information revealed by these studies will contribute to an enhanced understanding of wound repair under compromised conditions and provide insight into ways to effectively stimulate proper epithelial repair.
authors.affiliation: Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and.
authors.forename: Albert
authors.initials: A
authors.lastname: Lee
authors.affiliation: Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and.
authors.forename: Kelsey
authors.initials: K
authors.lastname: Derricks
authors.affiliation: Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and.
authors.forename: Martin
authors.initials: M
authors.lastname: Minns
authors.affiliation: Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Sophina
authors.initials: S
authors.lastname: Ji
authors.affiliation: Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Chi
authors.affiliation: Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Nugent
authors.affiliation: Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts vickery@bu.edu.
authors.forename: Vickery
authors.initials: V
authors.lastname: Trinkaus-Randall
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002450:Cell Communication; D015687:Cell Hypoxia / Q000235:genetics; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D018920:Coculture Techniques; D003315:Cornea / Q000187:drug effects / Q000378:metabolism*; D065306:Corneal Injuries; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D010100:Oxygen / Q000378:metabolism* / Q000494:pharmacology; D051419:Paxillin / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D062326:Re-Epithelialization / Q000235:genetics; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D012668:Trigeminal Ganglion / Q000187:drug effects / Q000293:injuries / Q000378:metabolism*
chemical_list: D005353:Fibronectins; D051419:Paxillin; D016194:Receptors, N-Methyl-D-Aspartate; D000255:Adenosine Triphosphate; D010100:Oxygen; D002118:Calcium
keywords: cell communication; hypoxia; imaging; wound healing