The neuronal nitric oxide synthase is upregulated in mouse skin repair and in response to epidermal growth factor in human HaCaT keratinocytes.
Expression of nNOS mRNA was found in normal human and mouse skin tissue. Upon wounding, we observed a rapid downregulation of nNOS mRNA and protein in wounds of mice; however, when repair continued, nNOS mRNA was strongly upregulated and nNOS protein expression peaked at late stages of healing. Immunohistochemistry revealed wound keratinocytes as the cellular source of nNOS. In line with the in vivo situation, we found a basal expression of nNOS in the human keratinocyte cell line HaCaT. A marked stimulation of nNOS expression in the cells was achieved with epidermal growth factor receptor (EGFR) ligands such as epidermal growth factor (EGF), heparin-binding EGF, transforming growth factor-alpha and two alternate splicing forms of the neuregulin gene. EGF-induced induction of nNOS was completely inhibited by the specific EGFR antagonist PD153035 and by the EGFR and Janus kinase 2/3 inhibitor AG490. Activation of EGFR might contribute to the observed upregulation of nNOS also in skin repair, as we found a spatial and temporal correlation of phosphorylated EGFR (Y1173) with nNOS expression at the wound site. Thus, in addition to the inducible- and endothelial-type NOS isoforms, also nNOS expression is regulated in the process of cutaneous wound repair.
Boissel
Jean-Paul
JP
Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany. boissel@mail.uni-mainz.de
Ohly
Dorothea
D
Bros
Matthias
M
Gödtel-Armbrust
Ute
U
Förstermann
Ulrich
U
Frank
Stefan
S
D000818:Animals; D002460:Cell Line; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D051379:Mice; D008807:Mice, Inbred BALB C; D019001:Nitric Oxide Synthase / Q000235:genetics* / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I; D012333:RNA, Messenger / Q000032:analysis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D020893:Receptor, ErbB-3 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D012867:Skin / Q000201:enzymology* / Q000293:injuries; D015854:Up-Regulation; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology*
D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; C496320:NOS1 protein, human; C496321:Nos1 protein, mouse