title: Transforming growth factor-beta response and expression in junctional and oral gingival epithelial cells.
abstract: The junctional (JE) and oral gingival (OGE) epithelium show distinct morphological phenotypes and express different cell surface and keratin markers. Transforming growth factor-beta (TGF-beta) has been shown to stimulate extracellular matrix formation and inhibit proteolytic matrix degradation in periodontal wound healing. To elucidate potential roles of TGF-beta in gingival epithelial regeneration and reattachment, the present study examined the effects of TGF-beta on JE and OGE cell growth and determined the patterns of expression of mRNAs for the TGF-beta isotypes beta 1, beta 2 and beta 3 and TGF-beta receptor types I, II and III. Primary cell cultures were initiated from JE and OGE and the cell phenotypes confirmed using monoclonal antibodies to specific keratins. TGF-beta induced a significant growth inhibition in OGE cells derived from 6 different patients with a mean inhibition of 46% and a range of 16-70% (p = 0.031). Although responses varied between patients, in general maximum inhibition occurred at 10 ng/ml TGF-beta. JE cells from 5 patients showed no significant growth inhibition by TGF-beta (p = 0.125). Greater expression of TGF-beta 2 and receptor type I mRNA was found in OGE than JE cells and thus appeared to be associated with differentiating epithelial cells. JE cells expressed more TGF-beta type II receptor specific mRNA than did OGE cells, but TGF-beta 1 mRNA expression was similar in JE and OGE cells. JE or OGE cultures derived from 2 of 3 patients showed expression of mRNA for the TGF-beta type III receptor. TGF-beta 3 mRNA was not detected in any of the JE or OGE samples examined. The greater sensitivity of OGE than JE to the growth inhibiting effects of TGF-beta correlated with higher expression of receptor type I mRNA which, together with the type II receptor, is required for sensitivity to growth inhibition by TGF-beta. The results suggest that, in addition to structural differences, the development of functional differences in the responses of JE and OGE to TGF-beta may be associated with the formation of JE from OGE cells and the reformation of attachment after periodontal surgery.
authors.affiliation: University of Texas, Health Science Center, Dental Branch, Department of Basic Sciences, Houston 77225, USA.
authors.forename: H
authors.initials: H
authors.lastname: Lu
authors.forename: I C
authors.initials: IC
authors.lastname: Mackenzie
authors.forename: A E
authors.initials: AE
authors.lastname: Levine
mesh_terms: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000235:genetics; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004846:Epithelial Attachment / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation; D005881:Gingiva / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006131:Growth Inhibitors / Q000494:pharmacology; D006801:Humans; D007633:Keratins / Q000187:drug effects / Q000235:genetics; D010519:Periodontium / Q000601:surgery; D010641:Phenotype; D011480:Protease Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D018125:Receptors, Transforming Growth Factor beta / Q000145:classification / Q000235:genetics; D012038:Regeneration; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000494:pharmacology*; D014945:Wound Healing
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D006131:Growth Inhibitors; D011480:Protease Inhibitors; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D007633:Keratins