JDR_Jon Mazz

Question 1

Does TLR9 mediate periodontal aging via senescence and inflammaging?

Answer 1

Souza JDR
3 Branches of the study:
* Human Case Control Study
* Animal Model (WT vs TLR9 -/- mice)
* Ex Vivo Model
Results: Gingiva in “old” people group (55 years +) had significantly more TLR9 than the “young” group (30-55 years)
Same findings in the “old” vs. “young” mice (8-10wks vs 22mos).
Conclusion: TLR9 targeting in elderly patients may help manage periodontitis.

Question 2

For Periodontitis and COVID-19, what are the biological mechanisms and meta-analysis of epidemiological evidence?

Answer 2

Baima JDR
NSSD = no clear association between COVID-19 and periodontitis.
The reason for the study was that inflammatory mediators & associated cell receptors might be related between periodontitis & COVID-19.

Question 3

Does t. denticola affect the brain and cause Alzheimer’s in mice?

Answer 3

Tang JDR
PG and TD were cultured.
4 groups of mice:
* sham infected
* T. denticola infected
* P. gingivalis infected
* TD and PG infected
Bacteria were administered to the gingival sulci in the mice.
Findings: Periodontal infection of mice with T. denticola led to increased:
alveolar bone loss
systemic inflammation
hippocampal inflammation
GSK3β activation
Tau phosphorylation

Conclusion:A periodontal T. denticola infection can colonize the hippocampus and cause hallmark signs of Alzheimer’s disease (Tau hyperphosphorylation) specifically through activation of GSK3β.

Question 4

What are the multicompartmental scaffolds for Periodontal tissue engineering?

Answer 4

Yao & Giannobile lab, JDR
Created 3 different scaffolds for periodontal regeneration: Monolithic, bicompartmental, tricompartmental.
The technique was melt electrowiring.
The tricompartment scaffold had zones for PDL, bone, and a central “mixing zone” where both cells can combine.
Findings: The lab successfully fabricated the tri-scaffold.
The scaffold promoted regeneration well (proliferation, expression, and cell alignment).

Question 5

How did dthey dissect B/Plasma cells in periodontitis at single-cell / bulk resolution?

Answer 5

Liu JDR
Purpose of the study was to create a “single cell transcriptomic study” to identify periodontitis.
Findings: A complex analysis of the differents cells & their associations was performed. The MIF (Macrophage migration inhibitory factor) was lower in periodontitis compared to health.
Conclusion: Different genes are expressed in plasma cells in healthy vs. diseased states. Detection of these genes can be useful diagnostically.

Question 6

Are there systemic morbidity clusters in people with periodontitis?

Answer 6

Larvin JDR
Used AI hypergraph analysis to see if other diseases/factors are connected to perio disease.
NHANES data was used.
Findings:
Factors related to mild periodontitis: Ethnicity (socioeconomic status), arthritis, obesity.
Factors related to severe periodontitis was related to smoking, diabetes, cancer.

Question 7

Do nociceptor neurons magnify host responses to aggravate periodontitis?

Answer 7

S. Wang JDR
Aim: The periodontium contains many nociceptive neurons that modulate the host response. TRPV1 was specifically examined in mice.
Methods: Mice had ligature-induced periodontitis. Control group had no injection; treatment group had Resiniferatoxin (“RTX” = an agonist of TRPV1) injected to the trigeminal nerve.
Findings: Ablation of TRPV1+ afferents decreases local host responses in periodontitis.
1) In mice with Vehicle injection into the TG, the fraction of the CD45+ leukocytes were about 30% of live single cells in 2 weeks after ligature placement, which is more than 5X greater than the unligatured control.

2) In mice injected with RTX into the TG, ligature-induced increases in the number 	of CD45+ cells and neutrophils were significantly lower than those in vehicle-	injected mice with ligature.

Question 8

Does human bone marrow stromal cell exosomes affect periodontitis?

Answer 8

Yue (Giannobile group), JDR
Aim: Investigate the effect of treating active periodontitis with hBMSC - derived exosomes. These were tested in vivo (rats)
Results:
* For macrophages challenged with E. coli LPS, exosome treated macrophages had a 50% reduction in production of Il-6
* For macrophages challenged with P. gingivalis, exosome treated macrophages had a marked reduction in production of Il-6 and cytokine genes Il6, Il1b, and Il10 had reduced expression.
* After exosome treatment, cmklr1, a gene related to inflammation resolution, had dramatically increased expression
Conclusion: These hBMSC exosomes may reduce periodontal inflammation and slow bone loss.