Areca nut extract-treated gingival fibroblasts modulate the invasiveness of polymorphonuclear leukocytes via the production of MMP-2.
BACKGROUND
Areca nut chewing is associated with an increase in the incidence of oral neoplastic or inflammatory diseases. Aberrations in matrix metalloprotease (MMP) expression are associated with the pathogenesis of oral diseases. This study investigated the potential effects of areca nut extract (ANE) on human gingival fibroblasts and the consequential impacts on inflammatory pathogenesis.


METHODS
Analyses of senescence marker, cell viability, changes of the cell cycle, and cell granularity in gingival fibroblasts together with an assessment of the invasiveness of polymorphonuclear (PMN) leukocytes after treatment with the supernatant of ANE-treated gingival fibroblasts were performed to characterize the phenotypic impacts. Western blotting and gelatin zymography were used to assay the expression and activity of MMP-2.


RESULTS
Chronic subtoxic (<10 microg/ml) ANE treatment resulted in premature growth arrest, appearance of senescence-associated beta-galactosidase activity and various other senescence-associated phenotypes in gingival fibroblasts. Gingival fibroblasts established from older individuals had a higher propensity to become ANE-induced senescent gingival fibroblasts. An activation of MMP-2 was identified in senescent cells. PMN leukocytes treated with the supernatant of ANE-induced senescent cells exhibited a significant increase in invasiveness, which was abrogated by both a MMP-2 blocker and a MMP-2 nullifying antibody.


CONCLUSIONS
This study provides evidence whereby MMP-2 secreted from ANE-induced senescent gingival fibroblasts would facilitate the invasiveness of PMN leukocytes, which could be associated with the oral inflammatory process in areca chewers.
Lu
Hsuan-Hsuan
HH
Institute of Oral Biology, School of Dentistry, National Yang-Ming University, Taipei, Taiwan.
Chen
Li-Kai
LK
Cheng
Chieh-Yuan
CY
Hung
Shan-Ling
SL
Lin
Shu-Chun
SC
Chang
Kuo-Wei
KW
D000906:Antibodies; D001114:Areca; D015415:Biomarkers / Q000032:analysis; D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects; D003594:Cytoplasmic Granules / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects* / Q000201:enzymology; D005881:Gingiva / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D020556:Neutrophil Infiltration / Q000502:physiology*; D009504:Neutrophils / Q000201:enzymology / Q000502:physiology*; D010641:Phenotype; D010936:Plant Extracts / Q000494:pharmacology*
D000906:Antibodies; D015415:Biomarkers; D004791:Enzyme Inhibitors; D006877:Hydroxamic Acids; D061965:Matrix Metalloproteinase Inhibitors; D010936:Plant Extracts; C474031:N-hydroxy-9-octadecenamide; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2