Insulin-like growth factor binding protein-5 enhances the migration and differentiation of gingival epithelial cells.
OBJECTIVE
The objective was to define the roles of insulin-like growth factor binding protein-5 (IGFBP-5) in gingival epithelial cells (GEC). Human IGFBP-5 is expressed in many cell types and has diverse biological functions. It stimulates the growth of bone cells and is associated with the impedance of gingival fibroblast apoptosis. In gingival epithelium, IGFBP-5 is expressed in the cells of the differentiated stratum spinosum layer.


METHODS
Recombinant IGFBP-5 protein treatment and knockdown of IGFBP-5 expression using a lentivirus-delivered short hairpin RNA was carried out in human GEC. Proliferation, apoptosis, anoikis, migration, differentiation and gene expression in GEC were analyzed and molecular images were obtained.


RESULTS
The IGFBP-5 had no effect on proliferation, but it slightly suppressed apoptosis and anoikis of GEC. It also induced GEC migration and upregulated the expression of involucrin, transglutaminase-1, keratin and focal adhesion kinase. The IGFBP-5 induced migration partly via an insulin-like growth factor-independent mechanism. The knockdown of IGFBP-5 downregulated the expression of involucrin, transglutaminase-1 and focal adhesion kinase.


CONCLUSIONS
Expression of IGFBP-5 in GEC is associated with anti-apoptosis, migration and differentiation of GEC. These phenotypic effects may be associated with focal adhesion kinase and are advantageous for re-epithelization of GEC and the maintenance of gingival health.
Hung
P-S
PS
Institute of Oral Biology, School of Dentistry, National Yang-Ming University, Taipei, Taiwan.
Kao
S-Y
SY
Liu
C-J
CJ
Tu
H-F
HF
Wu
C-H
CH
Lin
S-C
SC
D017209:Apoptosis; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D004847:Epithelial Cells / Q000378:metabolism; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000096:biosynthesis; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D005881:Gingiva / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000235:genetics* / Q000502:physiology*; D011498:Protein Precursors / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000494:pharmacology; D011503:Transglutaminases / Q000096:biosynthesis
D018975:Insulin-Like Growth Factor Binding Protein 5; D011498:Protein Precursors; D011994:Recombinant Proteins; C032253:involucrin; D011503:Transglutaminases; C105804:transglutaminase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases