Gingival transcriptome patterns during induction and resolution of experimental gingivitis in humans.
BACKGROUND
To our knowledge, changes in the patterns of whole-transcriptome gene expression that occur during the induction and resolution of experimental gingivitis in humans were not previously explored using bioinformatic tools.


METHODS
Gingival biopsy samples collected from 14 subjects during a 28-day stent-induced experimental gingivitis model, followed by treatment, and resolution at days 28 through 35 were analyzed using gene-expression arrays. Biopsy samples were collected at different sites within each subject at baseline (day 0), at the peak of gingivitis (day 28), and at resolution (day 35) and processed using whole-transcriptome gene-expression arrays. Gene-expression data were analyzed to identify biologic themes and pathways associated with changes in gene-expression profiles that occur during the induction and resolution of experimental gingivitis using bioinformatic tools.


RESULTS
During disease induction and resolution, the dominant expression pathway was the immune response, with 131 immune response genes significantly up- or downregulated during induction, during resolution, or during both at P <0.05. During induction, there was significant transient increase in the expression of inflammatory and oxidative stress mediators, including interleukin (IL)-1 alpha (IL1A), IL-1 beta (IL1B), IL8, RANTES, colony stimulating factor 3 (CSF3), and superoxide dismutase 2 (SOD2), and a decreased expression of IP10, interferon inducible T-cell alpha chemoattractant (ITAC), matrix metalloproteinase 10 (MMP10), and beta 4 defensin (DEFB4). These genes reversed expression patterns upon resolution in parallel with the reversal of gingival inflammation.


CONCLUSIONS
A relatively small subset (11.9%) of the immune response genes analyzed by array was transiently activated in response to biofilm overgrowth, suggesting a degree of specificity in the transcriptome-expression response. The fact that this same subset demonstrates a reversal in expression patterns during clinical resolution implicates these genes as being critical for maintaining tissue homeostasis at the biofilm-gingival interface. In addition to the immune response pathway as the dominant response theme, new candidate genes and pathways were identified as being selectively modulated in experimental gingivitis, including neural processes, epithelial defenses, angiogenesis, and wound healing.
Offenbacher
Steven
S
Department of Periodontology, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27709, USA. steve_offenbacher@dentistry.unc.edu
Barros
Silvana P
SP
Paquette
David W
DW
Winston
J Leslie
JL
Biesbrock
Aaron R
AR
Thomason
Ryan G
RG
Gibb
Roger D
RD
Fulmer
Andy W
AW
Tiesman
Jay P
JP
Juhlin
Kenton D
KD
Wang
Shuo L
SL
Reichling
Tim D
TD
Chen
Ker-Sang
KS
Ho
Begonia
B
D000293:Adolescent; D000328:Adult; D000368:Aged; D018441:Biofilms; D018946:Chemokine CCL5 / Q000235:genetics; D054357:Chemokine CXCL10 / Q000235:genetics; D054371:Chemokine CXCL11 / Q000235:genetics; D003115:Colony-Stimulating Factors / Q000235:genetics; D019295:Computational Biology; D003773:Dental Plaque / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D020869:Gene Expression Profiling / Q000379:methods*; D005802:Genes, MHC Class II / Q000235:genetics; D005881:Gingiva / Q000378:metabolism* / Q000473:pathology; D005891:Gingivitis / Q000209:etiology / Q000235:genetics* / Q000628:therapy; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D053582:Interleukin-1alpha / Q000235:genetics; D053583:Interleukin-1beta / Q000235:genetics; D016209:Interleukin-8 / Q000235:genetics; D008297:Male; D053506:Matrix Metalloproteinase 10 / Q000235:genetics; D008875:Middle Aged; D018384:Oxidative Stress / Q000235:genetics; D013482:Superoxide Dismutase / Q000235:genetics; D055815:Young Adult; D023083:beta-Defensins / Q000235:genetics; D000099156:Superoxide Dismutase 2
D018946:Chemokine CCL5; D054357:Chemokine CXCL10; D054371:Chemokine CXCL11; D003115:Colony-Stimulating Factors; D018836:Inflammation Mediators; D053582:Interleukin-1alpha; D053583:Interleukin-1beta; D016209:Interleukin-8; D053506:Matrix Metalloproteinase 10; D013482:Superoxide Dismutase; D023083:beta-Defensins; D000099156:Superoxide Dismutase 2; C483024:CCL5 protein, human; C515202:CXCL11 protein, human; C106641:DEFB4A protein, human; C511770:MMP10 protein, human