Periodontitis-resistant and -susceptible matriline regulation of gingival transcriptome in nonhuman primates

OBJECTIVE

This report identified if gingival gene expression transcriptomes demonstrated unique profiles that discriminated periodontitis-susceptible (PDS) and periodontitis-resistant (PDR) animals in health and disease.

BACKGROUND

Nonhuman primates generally organize their social groups based upon matriline origin. We have used a multi-generational colony of rhesus macaques to identify matrilines presenting with significant differences in periodontitis (e.g., earlier age onset, greater prevalence, and severity).

METHODS

Animals from 12 to 23 years of age (n = 17; 8 - PDR, 9 - PDS) were entered into a ligature-induced periodontitis trial. Gingival biopsies were taken at baseline and 0.5, 1, 3, and 5 months post-ligation, and microarray analysis was used to quantify gene expression in samples at each time point.

RESULTS

Over 1000 genes showed significant (p < .01) differences in the PDR versus PDS animals at baseline. The frequency of differences generally decreased during the disease process, and increased with resolution (i.e., 5 months). A nearly 2:1 ratio of elevated gene levels was noted in baseline PDR samples that included up-regulated MMPs, Fc receptors, chemokines, interleukins, and innate immune receptors, and down-regulated genes particularly related to epithelial biology. Most dramatically, there was a skewed differential expression of adaptive immune response genes in the PDR and epithelial cell structure/function genes in PDS samples.

CONCLUSIONS

The results demonstrate substantive differences in gingival tissue response capacity/programming in PDR and PDS samples that may contribute to the differences in clinical outcomes related to the heritability of disease risk through matrilines.

Sex and Age Effects on Healthy Gingival Transcriptomic Patterns

Many chronic inflammatory diseases demonstrate demographic associations such as sex, age, and race-ethnicity. Periodontitis has been found to be increased with age and in males. This study used nonhuman primates representing a human-like model for periodontitis and examined the gingival transcriptome stratified on sex and age. Thirty-six Macaca mulatta in 4 age groups-young (<3 y), adolescent (3-7 y), adult (12-15 y), and aged (>17 y)-with a healthy periodontium were used to characterize gene expression in healthy gingival tissues. Gene expression was compared to clinical measures of bleeding on probing (BOP) and probing pocket depth (PPD). The results demonstrated sex differences in number of up- and downregulated genes that increased with age. Female animals generally showed elevated expression of genes related to host immunoinflammatory responses, and males showed increased expression of tissue structural genes. Gene expression correlations with BOP and/or PPD showed minimal overlap between the sexes, while male animals demonstrated substantial overlap in genes that correlated with both BOP and PPD clinical features. A cluster analysis of genes significantly different between sexes showed a clear sex and age discrimination in the young and adolescent animals. In the older groups, the genes clustered predominately by sex, irrespective of age group. A pathway analysis identified that significant gene expression patterns were quite similar in adolescent and adult animals, while the young and aged samples were quite distinct. The results confirmed substantial sex related variations in gingival tissue biology that were affected by age and observed even in adolescent animals. This suggests that "programming" of the gingival tissues related to sex can occur rather early in life and presage variations in future risk for periodontitis.

Biological Aging and Periodontal Disease: Analysis of NHANES (2001-2002)

INTRODUCTION

Periodontitis is a chronic inflammatory disease caused by multiple potential contributing factors such as bacterial biofilm infection of the tissues surrounding the teeth and environmental determinants and a dysregulated host response for modifying and resolving the inflammation. Because periodontal disease is a major public health concern with substantial increases in the prevalence and severity in aging populations, previous studies of periodontitis tended to approach the disease as an age-associated outcome across the life span. However, few investigations have considered that, as a chronic noncommunicable disease, periodontitis may not simply be a disease that increases with age but may contribute to more rapid biologic aging.

OBJECTIVES

Increasing population data supports the potential disconnect between chronological aging and biologic aging, which would contribute to the heterogeneity of aging phenotypes within chronologic ages across populations. Thus, our aim was to test whether periodontal disease affects biological aging across the life span.

METHODS

The prevalence of periodontitis in the adult US population is a portion of the assessment of the National Health and Nutrition Examination Survey (NHANES), which has been ongoing since 1971 through 2-y cycles sampling populations across the country. We used NHANES 2001-2002 to test the hypothesis that the presence/severity of periodontal disease as an exposure variable would negatively affect telomere length, a measure of biological aging, and that this relationship is modified by factors that also affect the progression of periodontitis, such as sex, race/ethnicity, and smoking.

RESULTS

The data demonstrated a significant impact of periodontitis on decreasing telomere lengths across the life span. These differences were modulated by age, sex, race/ethnicity, and smoking within the population.

CONCLUSION

The findings lay the groundwork for future studies documenting broader effects on biological aging parameters as well as potential intervention strategies for periodontitis in driving unhealthy aging processes.

KNOWLEDGE TRANSFER STATEMENT

Periodontitis is a chronic inflammatory disease and dysregulated host response. Shortening of telomeres is a reflection of biologic aging. Decreased telomere lengths with periodontitis are seemingly related to chronic infection and persistent local and systemic inflammation. These findings suggest that periodontitis is not simply a disease of aging but may also transmit chronic systemic signals that could affect more rapid biological aging. Clinicians can use this outcome to recognize the role of periodontitis in driving unhealthy aging processes in patients.

Effectiveness of cervical pessary compared to cervical cerclage with or without vaginal progesterone for the prevention of preterm birth in women with twin pregnancies and a short cervix: study protocol for a two-by-two factorial randomised clinical trial

INTRODUCTION

Women with twin pregnancies and a short cervix are at increased risk for preterm birth (PTB). Given the burden of prematurity and its attendant risks, the quest for effective interventions in twins has been an area of considerable research. Studies investigating the effectiveness of cervical cerclage, cervical pessary and vaginal progesterone in preventing PTB have yielded conflicting results. The aim of this study is to compare the effectiveness of cervical pessary and cervical cerclage with or without vaginal progesterone to prevent PTB in women with twin pregnancies and a cervical length (CL) ≤ 28 mm.

METHODS AND ANALYSIS

This multicentre, randomised clinical trial will be conducted at My Duc Hospital and My Duc Phu Nhuan Hospital, Vietnam. Asymptomatic women with twin pregnancies and a CL ≤28 mm, measured at 16-22 weeks' gestation, will be randomised in a 1:1:1:1 ratio to receive a cerclage, pessary, cerclage plus progesterone or pessary plus progesterone. Primary outcome will be PTB <34 weeks. Secondary outcomes will be maternal and neonatal complications. We preplanned a subgroup analysis according to CL from all women after randomisation and divided into four quartiles. Analysis will be conducted on an intention-to-treat basis. The rate of PTB <34 weeks' gestation in women with twin pregnancies and a cervix ≤28 mm and treated with pessary in our previous study at My Duc Hospital was 24.2%. A sample size of 340 women will be required to show or refute that cervical cerclage decreases the rate of PTB <34 weeks by 50% compared with pessary (from 24.2% to 12.1%, α level 0.05, power 80%, 5% lost to follow-up and protocol deviation). This study is not to be powered to assess interactions between interventions.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Institutional Ethics Committee of My Duc Hospital and informed patient consent was obtained before study enrolment. Results of the study will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03863613 (date of registration: 4 March 2019).

Stress tuning of the fundamental absorption edge of pure germanium waveguides

One-dimensional stress dependence on the fundamental absorption edge of pure germanium (Ge) waveguide has theoretically and experimentally been studied, considering built-in two-dimensional stress-tensile Ge grown on Si. Based on the results, we have designed Ge Franz-Keldysh (FK) electroabsorption (EA) modulators to work at 1550 nm. Application of one-dimensional [110] compressive stress above -350 MPa on a pure Ge [-110] waveguide should allow 1550 nm light transmission, unless otherwise a pure Ge modulator can only operate at 1600 nm or longer due to the built-in two-dimensional tensile stress in Ge. The prediction has experimentally been verified using a SiNx stressor film. This concludes that the presented stress-tuning approach of the pure Ge waveguides should expand the operation wavelength of Ge FK-EA modulators to C band. Since stress tuning can be locally done in the back-end-of-line of complementary metal oxide semiconductor (CMOS) process, the presented stress-tuning method should enable "field-programable" control of the operation wavelengths of the monolithically integrated Ge modulators in Si photonics platform.

Local bandgap control of germanium by silicon nitride stressor

We have proposed a new approach to tune the operation wavelength of Franz-Keldysh Ge electro-absorption modulation in Si photonics by controlling the local strain environment to cover the whole range of C + L bands (1.53 - 1.62 μm). The present paper shows a proof of strain-tuning modulator concept by the shift of the Ge absorption edge using SiN(x) stressor films and Franz-Keldysh effect in strain-controlled Ge.

Interstitial fluids associated with wound repair support proliferation but not differentiation of neonatal rat myoblasts in vitro

The ability of wound fluids to support events required for skeletal muscle regeneration was examined. Wound fluids were obtained from polyvinyl alcohol sponges 1, 3, 5, 10, and 15 days after implantation. Neonatal rat L8 myoblasts were used to test the ability of early wound fluids to promote myoblast proliferation and late wound fluids to promote myoblast differentiation-two characteristics deemed critical for effective skeletal muscle regeneration. Early wound fluids (1- and 3-day) stimulated DNA replication by myoblasts, as judged by tritiated thymidine uptake, up to ninefold (p < 0.05). Later wound fluids (5-, 10-, and 15-day) displayed decreasing ability to stimulate proliferation, with 15-day wound fluid failing to significantly stimulate proliferation. In contrast, myoblast differentiation, as judged by myotube fusion and creatine kinase activity, was progressively reduced by wound fluids of increasing age. In fact, late wound fluids (5, 10, and 15 days) reduced myotube fusion by 88% to 100% and depressed creatine kinase activity by 60% to 75% (p < 0.05). Thus, wound fluids from a repair environment appear to support myoblast proliferation early but suppress myoblast differentiation later. These characteristics suggest that the wound repair environment cannot fully support skeletal muscle regeneration.

Human papillomavirus-associated oropharyngeal cancer: a new clinical entity

The incidence of oropharyngeal cancers is rising worldwide in both nonsmokers and nondrinkers. Epidemiology studies suggest a strong association between human papillomavirus (HPV) 16 infection, changing sexual behavior and cancer development. Despite initial presentation with locally advanced disease and poorly differentiated histology, HPV-associated oropharyngeal carcinoma is associated with a good prognosis because its response to chemotherapy and radiation. Clinicians should be aware of the risk of oropharyngeal cancer in young people to avoid unnecessary delay in diagnosis and treatment. A history of oral sex should be elicited in young patients with enlarged neck nodes and/or tonsillar masses.

Mammalian wound repair environment does not permit skeletal muscle regeneration

Repair and regeneration are mutually exclusive responses to injury. Previous studies have shown that wound fluids promote proliferation, but not differentiation, of myoblasts in vitro. This study explored the ability of the repair environment within polyvinyl alcohol sponges to support cellular events of skeletal muscle regeneration in vivo. Neonatal rat L8 myoblasts were modified to express beta-galactosidase then inoculated into plain sponges or sponges containing minced muscle. Labeled myoblasts were found in myotubes within minced muscle. In contrast, myoblasts inoculated into sponges lacking muscle remained mononucleate. Occurrence of labeled myoblasts within myotubes, which required fusion, represents differentiation of inoculated myoblasts to participate in regeneration. Failure of myoblasts to form myotubes in sponges lacking muscle suggests that this wound repair environment cannot support morphologic differentiation of myoblasts. Although this repair environment can support the survival of myoblasts, it did not support myogenesis, an event necessary to complete skeletal muscle regeneration. Data from this study reinforce earlier studies in vitro and suggest that the properties attributed to wound fluids are inherent in the wound environment. Whether the inability of this environment to support myogenesis is the consequence of the absence of essential factors or the presence of inhibitors remains to be determined.

An in vivo model for evaluating wound repair and regeneration microenvironments

BACKGROUND

Factors differentially regulating regeneration and repair as contrasting resolutions to injury are unknown. We adapted a common wound healing model to further characterize mammalian wound repair and regeneration microenvironments.

METHODS

Polyvinyl alcohol sponges, sponges containing minced muscle, or blocks of minced muscle were implanted onto the backs of Fischer rats. Vascularization was assessed by infusion with india ink and progress of regeneration was evaluated histologically.

RESULTS

Regeneration occurring within sponges was histologically similar to that of free muscle blocks; but, was initiated more slowly. Vascularization of minced muscle implanted in sponges was delayed slightly compared to implanted free muscle blocks.

CONCLUSIONS

Regeneration of minced muscle in sponges parallels normal regeneration of free minced muscle. Incorporation into a wound repair model provides access to interstitial fluids conditioned by regenerating muscle and will lead to more detailed comparisons of the content and properties of repair and regeneration microenvironments.

gem-Diphosphonate and gem-phosphonate-phosphate compounds with specific high density lipoprotein inducing activity

New diphosphonate compounds and related derivatives were synthesized and investigated for their activity in specifically inducing plasma high density lipoproteins (HDL) and high density lipoprotein cholesterol (HDL-C) in normal rats. The screening of numerous compounds has permitted the determination of the structural variations leading to optimal plasma lipid altering activity, indicating antiatherosclerotic potential. Among the compounds observed to be the most active, dimethyl alpha-(dimethoxyphosphinyl)-p-chlorobenzyl phosphate (20, SR-202, mifobate) was selected for further pharmacological and subsequent clinical development.