Temporal activation of anti- and pro-apoptotic factors in human gingival fibroblasts infected with the periodontal pathogen, Porphyromonas gingivalis: potential role of bacterial proteases in host signalling

BACKGROUND: Porphyromonas gingivalis is the foremost oral pathogen of adult periodontitis in humans. However, the mechanisms of bacterial invasion and the resultant destruction of the gingival tissue remain largely undefined. RESULTS: We report host-P. gingivalis interactions in primary human gingival fibroblast (HGF) cells. Quantitative immunostaining revealed the need for a high multiplicity of infection for optimal infection. Early in infection (2–12 h), P. gingivalis activated the proinflammatory transcription factor NF-kappa B, partly via the PI3 kinase/AKT pathway. This was accompanied by the induction of cellular anti-apoptotic genes, including Bfl-1, Boo, Bcl-XL, Bcl2, Mcl-1, Bcl-w and Survivin. Late in infection (24–36 h) the anti-apoptotic genes largely shut down and the pro-apoptotic genes, including Nip3, Hrk, Bak, Bik, Bok, Bax, Bad, Bim and Moap-1, were activated. Apoptosis was characterized by nuclear DNA degradation and activation of caspases-3, -6, -7 and -9 via the intrinsic mitochondrial pathway. Use of inhibitors revealed an anti-apoptotic function of NF-kappa B and PI3 kinase in P. gingivalis-infected HGF cells. Use of a triple protease mutant P. gingivalis lacking three major gingipains (rgpA rgpB kgp) suggested a role of some or all these proteases in myriad aspects of bacteria-gingival interaction. CONCLUSION: The pathology of the gingival fibroblast in P. gingivalis infection is affected by a temporal shift from cellular survival response to apoptosis, regulated by a number of anti- and pro-apoptotic molecules. The gingipain group of proteases affects bacteria-host interactions and may directly promote apoptosis by intracellular proteolytic activation of caspase-3

Relationship of Chinese Tungusic ethnic minorities with Okhotsk cultural people in regard to dental metric traits

We used crown measurements to analyze the anthropological characteristics of three Tungusic tribes, Ewenki, Hezhen, and Oroqen, residing in the Amur River basin of China. Previous findings suggest that Amur River basin populations were involved in the population structure of Tungusic people. We then compared our findings with those of individuals with a north Asian ethnic background to examine the distribution of those characteristics in north Asian Mongoloids (1). The total crown area was classified as Sinodont (2). A deviation diagram showed scant differences among Hezhen, Oroqen, and Okhotsk individuals, indicating the closeness of those populations (3). Q-mode correlation coefficients and 2-dimensional expression suggested that Tungusic individuals were the Central Asia type. Hezhen and Oroqen were plotted closer to Okhotsk cultural people, and closely related. Race mixture occurred among the Baikal, then spread from Lake Baikal and Central Asia from the south in the post-Neolithic Era, and the groups gradually diffused to the lower Amur region. Therefore, it is reasonable to conclude that a different degree of miscegenation occurred between the Baikal and Central Asian regions in the area from Lake Baikal to lower Amur in accordance with the geographical features

Determination of Cortisol and Dehydroepiandrosterone Levels in Saliva for Screening of Periodontitis in Older Japanese Adults

Background. Recent reports have found a positive relationship between periodontitis and the hormones cortisol and dehydroepiandrosterone (DHEA). We investigated the associations between those levels and periodontitis in never-smokers and smokers of elderly subjects. Subjects and Methods. Cortisol and DHEA levels in saliva were determined in 171 subjects (85 males, 86 females), with clinical examinations including probing depth (PD) and clinical attachment loss (CAL) also performed. Results. Smoking had effects on cortisol and DHEA levels, and those were significantly associated with severe PD and CAL in never-smokers. According to ROC analysis, the cutoff values of cortisol and DHEA to obtain the optimal sensitivity and specificity for detecting severe periodontitis were 2.06 ng/mL and 60.24 pg/mL, respectively, for PD, and 2.12 ng/mL and 61.78 pg/mL, respectively, for CAL. Conclusions. Assessment of hormone levels may be a useful screening method for periodontitis, though limited to never-smokers

Effect of lifestyle on 6‐year periodontitis incidence or progression and tooth loss in older adults

AimTo evaluate the longitudinal association of combined healthy lifestyle factors with incidence or progression of periodontitis and tooth loss in older adults.Materials and methodsThis 6‐year study included 374 Japanese 70‐year olds with 7,157 teeth, from a source eligible baseline population of 554 individuals. Four lifestyle factors—cigarette smoking, physical activity, relative weight, and dietary quality—were scored as healthy (1 point) or unhealthy (0 point). Adding the individual scores generated the “healthy lifestyle score” (0–4 points). Multilevel mixed‐effects logistic regression models were applied to evaluate tooth‐specific associations between the baseline healthy lifestyle score and the incidence or progression of periodontitis (increase in clinical attachment loss ≥3 mm) and tooth loss.ResultsAfter 6 years, 19.0% of the teeth exhibited periodontitis incidence or progression and 8.2% were lost. Compared with a healthy lifestyle score of 0–1 (least healthy), the highest score (4 points) was associated with a significantly lower tooth‐specific risk of periodontitis (adjusted odds ratio = 0.32; 95% confidence interval: 0.16–0.62) and tooth loss (adjusted odds ratio = 0.42; 95% confidence interval: 0.23–0.77).ConclusionsSimultaneous adherence to multiple healthy lifestyle factors significantly lowers the risk of incidence or progression of periodontitis and tooth loss in older adults.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145573/1/jcpe12920_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145573/2/jcpe12920.pd

Relationship between tooth loss and mortality in 80-year-old Japanese community-dwelling subjects

<p>Abstract</p> <p>Background</p> <p>Findings from several studies suggest associations between tooth loss and health outcomes, including malnutrition, poor quality of life, and mortality, in older individuals. However, limited information is available regarding whether those associations remain true in very elderly subjects after adequately considering confounding factors such as sex and smoking status. Herein, we determined whether the number of teeth in 80-year-old subjects is an independent predictor of mortality.</p> <p>Methods</p> <p>We initially contacted 1282 80-year-old community-dwelling individuals born in 1917, of whom 697 responded and participated in a baseline study, with follow-up examinations conducted 4 and 5.5 years later. Data from interviews and medical and oral examinations were obtained, and oral health was determined according to the number of teeth remaining in the oral cavity.</p> <p>Results</p> <p>A total of 108 and 157 subjects died in 4 years and 5.5 years, respectively, after the baseline study. Tooth loss was significantly associated with mortality at age 85.5, but not at age 84, after adjusting for potential confounders. When the analysis was stratified by sex, we found a stronger association in females in follow-up examinations conducted at both 4- and 5.5 years. On the other hand, the effect of tooth loss on mortality was not significantly different between smokers and non-smokers.</p> <p>Conclusion</p> <p>Tooth loss is a significant predictor of mortality independent of health factors, socio-economic status, and lifestyle in octogenarians, with a stronger association in females.</p

Hyposalivation and 10‐year all‐cause mortality in an elderly Japanese population

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143602/1/ger12319.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143602/2/ger12319_am.pd