KGF-1 and KGF receptor expression in human periodontal disease and in vitro microwounding-associated-ligand-independent KGFR activation

Min Li
Objectives: Periodontal disease is a chronic inflammation resulting in periodontal attachment loss. Keratinocyte Growth Factor-1 (KGF-1) is upregulated in chronic inflammation and specifically stimulates epithelial cell proliferation by signaling through the epithelial-specific Keratinocyte Growth Factor Receptor (KGFR). First, we examined KGF-1 and KGFR expression and localization in human periodontal tissues. Second, we extended these studies by developing an in vitro mechanical wound model
more » ... mimic trauma to the periodontal pocket epithelium and examined ligand independent KGFR activation and cell migration. Methods: In our study of human gingival tissues, we used immunohistochemistry and laser capture microdissection with RT-PCR to analyze KGF-1 and KGFR expression and localization. To study ligand independent KGFR phosphorylation, KGFR internalization along the wound edge was imaged using immunohistochemical staining and KGFR phosphorylation confirmed using immunoprecipitation with western blotting. Wounding induced oxidative stress was detected using DCFH-DA (2',7'-dichlorofluorescin diacetate) and modulated by pretreatment with an antioxidant. Changes in migration were examined in the presence or absence of pathway specific inhibitors. Results: KGF-1 protein localized to areas of junctional and basal oral epithelial cells was significantly increased in periodontal pocket epithelium (p<0.01) and oral epithelium (p<0.05) of disease-associated tissues. KGFR localized to the junctional and the parabasal cells of oral epithelium, and was increased in disease-associated pocket epithelium (p<0.05). Laser capture microdissection with RT-PCR confirmedKGF-1 and KGFR were specifically expressed by connective tissue and epithelium, respectively. In our cell culture model, mechanical wounding induced ligand independent KGFR activation. ROS (Reactive Oxygen Species) generation along the wound edge was associated with KGFR activation and scavenging of ROS reduced KGFR phosphorylation. The c-Src family inhibitor, [...]
doi:10.14288/1.0066268 fatcat:svc3mds53vaphiaubenmwkxucq