Zinc accumulation and metallothionein gene expression in the proliferating epidermis during wound healing in mouse skin.
Metallothionein (MT), a low molecular weight metal-binding protein, has been related to zinc and copper metabolism, the acute-phase response, and cellular proliferation. In this study, we investigated changes in zinc metabolism and MT gene expression occurring in tissue damage and repair during wound healing in mouse skin. Northern blot analysis revealed that a significant increase of MT mRNA was observed in the liver for 18 h after wounding, and serum zinc downfall and hepatic zinc uptake were observed. In situ hybridization analysis showed that no significant expression of MT mRNA was detected within the first 9 h after wounding. However, it was expressed restrictively in the proliferating epidermis of the wound margin after 12 h. Zinc began to accumulate in wounded skin after MT gene expressed. Northern blotting and immunocytochemical staining revealed that MT has been synthesized actively during the growth phase compared with the stationary phase in normal human epidermal keratinocytes in vitro. Intracellular zinc accumulation was observed in the proliferating cells. We concluded that hepatic MT plays an important role as an acute phase protein against host damage, and epidermal MT contributes in the supply of zinc to wounded tissue and activates proliferation for the regeneration of epidermis.
Iwata
M
M
Department of Oral and Maxillofacial Surgery II, Okayama University Dental School, 2-5-1 Shikata-Cho, Okayama 700-8525, Japan.
Takebayashi
T
T
Ohta
H
H
Alcalde
R E
RE
Itano
Y
Y
Matsumura
T
T
D000818:Animals; D015152:Blotting, Northern; D002455:Cell Division; D004817:Epidermis / Q000378:metabolism* / Q000473:pathology; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D017403:In Situ Hybridization; D008099:Liver / Q000378:metabolism; D008297:Male; D008668:Metallothionein / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008819:Mice, Nude; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014945:Wound Healing / Q000502:physiology*; D015032:Zinc / Q000378:metabolism*
D012333:RNA, Messenger; D008668:Metallothionein; D015032:Zinc