Immunolocalization of laminin and integrin in regenerating junctional epithelium of mice after gingivectomy.
OBJECTIVE
The expression patterns of adhesive proteins and extracellular matrix proteins in regenerating gingival epithelium after gingivectomy are unknown. The aim of this study was to examine the expression of laminin 1, laminin gamma(2) (a specific component of laminin 5), integrin beta(4) and integrin alpha(3) in the regenerating gingival epithelium in order to understand the mechanism of wound healing during reconstitution of the sulcular environment.


METHODS
The palatal gingivae of the maxillary molars of Institute of Cancer Research mice were excised, and the regenerating tissues were examined 1, 3, 5, 7 and 14 days later. Fresh, non-fixed and non-decalcified frozen sections were prepared and stained using immunofluorescence.


RESULTS
At 1 day post-surgery, intense expression of laminin gamma(2), integrin beta(4) and integrin alpha(3) was distinct in the frontal margin of the regenerating oral epithelium. Laminin gamma(2) was diffusely detected on the root surface and in connective tissues beneath the regenerating oral epithelium at 3 and 5 days. At 7 days, laminin gamma(2) was intermittently recognizable in the internal basal lamina (IBL) close to tooth-facing cells, while laminin gamma(2), integrin beta(4) and integrin alpha(3) were observed in the IBL and in the external basal lamina (EBL) of the regenerating junctional epithelium at 14 days.


CONCLUSIONS
These results suggest that secretion of laminin 5 in the connective tissue may induce epithelial cell migration, and that binding of laminin 5 to integrin alpha(6)beta(4) and integrin alpha(3)beta(1) in the IBL may provoke cell adhesion and migration of cells facing the tooth on the enamel surface of the regenerating junctional epithelium.
Masaoka
T
T
Oral Health Science Center HRC7, Tokyo Dental College, Chiba, Japan.
Hashimoto
S
S
Kinumatsu
T
T
Muramatsu
T
T
Jung
H-S
HS
Yamada
S
S
Shimono
M
M
D000818:Animals; D001485:Basement Membrane / Q000473:pathology; D002448:Cell Adhesion / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000032:analysis; D002465:Cell Movement / Q000502:physiology; D003238:Connective Tissue / Q000473:pathology; D004846:Epithelial Attachment / Q000473:pathology*; D004848:Epithelium / Q000473:pathology; D005881:Gingiva / Q000473:pathology; D005890:Gingivectomy; D039422:Integrin alpha3 / Q000032:analysis; D039663:Integrin beta4 / Q000032:analysis; D016023:Integrins / Q000032:analysis*; D007797:Laminin / Q000032:analysis*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D012038:Regeneration / Q000502:physiology*; D013997:Time Factors; D019237:Tooth Cervix / Q000473:pathology; D014092:Tooth Root / Q000473:pathology; D000097794:Kalinin
D015815:Cell Adhesion Molecules; D039422:Integrin alpha3; D039663:Integrin beta4; D016023:Integrins; D007797:Laminin; D000097794:Kalinin; C121346:laminin 1