The Role of DNA Methylation and Histone Modification in Periodontal Disease: A Systematic Review.

Despite a number of reports in the literature on the role of epigenetic mechanisms in periodontal disease, a thorough assessment of the published studies is warranted to better comprehend the evidence on the relationship between epigenetic changes and periodontal disease and its treatment. Therefore, the aim of this systematic review is to identify and synthesize the evidence for an association between DNA methylation/histone modification and periodontal disease and its treatment in human adults. A systematic search was independently conducted to identify articles meeting the inclusion criteria. DNA methylation and histone modifications associated with periodontal diseases, gene expression, epigenetic changes after periodontal therapy, and the association between epigenetics and clinical parameters were evaluated. Sixteen studies were identified. All included studies examined DNA modifications in relation to periodontitis, and none of the studies examined histone modifications. Substantial variation regarding the reporting of sample sizes and patient characteristics, statistical analyses, and methodology, was found. There was some evidence, albeit inconsistent, for an association between DNA methylation and periodontal disease. IL6, IL6R, IFNG, PTGS2, SOCS1, and TNF were identified as candidate genes that have been assessed for DNA methylation in periodontitis. While several included studies found associations between methylation levels and periodontal disease risk, there is insufficient evidence to support or refute an association between DNA methylation and periodontal disease/therapy in human adults. Further research must be conducted to identify reproducible epigenetic markers and determine the extent to which DNA methylation can be applied as a clinical biomarker.

Niacin Ameliorates Neuro-Inflammation in Parkinson's Disease via GPR109A.

In this study, we used macrophage RAW264.7 cells to elucidate the molecular mechanism underlying the anti-inflammatory actions of niacin. Anti-inflammatory actions of niacin and a possible role of its receptor GPR109A have been studied previously. However, the precise molecular mechanism of niacin's action in reducing inflammation through GPR109A is unknown. Here we observed that niacin reduced the translocation of phosphorylated nuclear kappa B (p-NF-κB) induced by lipopolysaccharide (LPS) in the nucleus of RAW264.7 cells. The reduction in the nuclear translocation in turn decreased the expression of pro-inflammatory cytokines IL-1ß, IL-6 in RAW264.7 cells. We observed a decrease in the nuclear translocation of p-NF-κB and the expression of inflammatory cytokines after knockdown of GPR109A in RAW264.7 cells. Our results suggest that these molecular actions of niacin are mediated via its receptor GPR109A (also known as HCAR2) by controlling the translocation of p-NF-κB to the nucleus. Overall, our findings suggest that niacin treatment may have potential in reducing inflammation by targeting GPR109A.

Safety and Immunological Efficacy of a DNA Vaccine Encoding the Androgen Receptor Ligand-Binding Domain (AR-LBD).

BACKGROUND: The androgen receptor (AR) is a key oncogenic driver of prostate cancer, and has been the primary focus of prostate cancer treatment for several decades. We have previously demonstrated that the AR is also an immunological target antigen, recognized in patients with prostate cancer, and targetable by means of vaccines in rodent models with delays in prostate tumor growth. The current study was performed to determine the safety and immunological efficacy of a GMP-grade plasmid DNA vaccine encoding the ligand-binding domain (LBD) of the AR, pTVG-AR. METHODS: Groups of male mice (n = 6-10 per group) were evaluated after four or seven immunizations, using different schedules and inclusion of GM-CSF as a vaccine adjuvant. Animals were assessed for toxicity using gross observations, pathological analysis, and analysis of serum chemistries. Animals were analyzed for evidence of vaccine-augmented immunity by tetramer analysis. Survival studies using different immunization schedules and inclusion of GM-CSF were conducted in an autochthonous genetically engineered mouse model. RESULTS: No significant toxicities were observed in terms of animal weights, histopathology, hematological changes, or changes in serum chemistries, although there was a trend to lower serum glucose in animals treated with the vaccine. There was specifically no evidence of toxicity in other tissues that express AR, including liver, muscle, hematopoietic, and brain. Vaccination was found to elicit AR LBD-specific CD8+ T cells. In a subsequent study of tumor-bearing animals, animals treated with vaccine had prolonged survival compared with control-immunized mice. CONCLUSIONS: These studies demonstrate that, in immunocompetent mice expressing the target antigen, immunization with the pTVG-AR vaccine was both safe and effective in eliciting AR-specific cellular immune responses, and prolonged the survival of prostate tumor-bearing mice. These findings support the clinical evaluation of pTVG-AR in patients with recurrent prostate cancer. Prostate 77:812-821, 2017. © 2017 Wiley Periodicals, Inc.

Oxidative stress in songbirds exposed to dietary methylmercury.

Long-term, sublethal methylmercury exposure can cause reproductive depression, immune suppression, endocrine disruption and other problems in birds. We used two biomarkers to detect oxidative stress in livers of zebra finches (Taeniopygia guttata) developmentally exposed to sublethal levels of dietary methylmercury (0.0, 0.3, 0.6, 1.2, or 2.4 µg/g wet weight in diet). Our findings indicate that young adult finches exposed to environmentally relevant concentrations of mercury in ovo and through their diets, exhibited oxidative stress in their livers. We measured the ratio of the antioxidant glutathione in its reduced form (GSH) versus its oxidized form (GSSG) and the activity of the superoxide dismutase (SOD) enzyme suite. Blood total mercury served as a proxy for liver mercury concentration, and was on average 8.4 times the dietary dose (e.g., birds consuming 0.6 µg/g had blood mercury levels of ~5 µg/g on a wet weight basis). Consistent with what is known from large, aquatic bird species, there was a significant, negative relationship between GSH/GSSG ratios and tissue mercury concentrations, which is indicative of oxidative stress. This relationship was driven by a significant increase in the oxidized glutathione in the livers of birds with higher blood mercury levels. SOD activity was also found to have a significant, negative relationship with blood mercury.

The effect of mercury on baseline corticosterone in a breeding songbird.

Although songbirds accumulate mercury at rates equivalent to better-studied aquatic avian species, effects of mercury bioaccumulation in songbirds remain understudied. Little is known about the effects of mercury on endocrine physiology, but recent evidence indicates that mercury may disrupt the function of the hypothalamic-pituitary-adrenal axis. Both field-based correlational studies and a recent dosing experiment suggest that mercury exposure alters levels of the primary avian stress hormone, CORT. We sampled zebra finches that had been dosed with 0, 0.5, or 1.0 ppm dietary methylmercury for baseline CORT twice; once during pairing and once after successfully fledging young. Circulating levels of CORT were not significantly affected by mercury exposure. However, our findings indicate potentially important differences in CORT responses between the sexes when exposed to environmentally relevant doses of mercury across the nesting cycle.

Regulation of embryonic stem cell pluripotency by heat shock protein 90.

Deciphering the molecular basis of stem cell pluripotency is fundamental to the understanding of stem cell biology, early embryonic development, and to the clinical application of regenerative medicine. We report here that the molecular chaperone heat shock protein 90 (Hsp90) is essential for mouse embryonic stem cell (ESC) pluripotency through regulating multiple pluripotency factors, including Oct4, Nanog, and signal transducer and activator of transcription 3. Inhibition of Hsp90 by either 17-N-Allylamino-17-demethoxygeldanamycin or miRNA led to ESC differentiation. Overexpression of Hsp90ß partially rescued the phenotype; in particular, the levels of Oct4 and Nanog were restored. Notably, Hsp90 associated with Oct4 and Nanog in the same cellular complex and protected them from degradation by the ubiquitin proteasome pathway, suggesting that Oct4 and Nanog are potential novel Hsp90 client proteins. In addition, Hsp90 inhibition reduced the mRNA level of Oct4, but not that of Nanog, indicating that Hsp90 participates in Oct4 mRNA processing or maturation. Hsp90 inhibition also increased expression of some protein markers for mesodermal lineages, implying that Hsp90 suppresses mesodermal differentiation from ESCs. These findings support a new role for Hsp90 in maintaining ESC pluripotency by sustaining the level of multiple pluripotency factors, particularly Oct4 and Nanog.

Necrotizing Fasciitis of the Hand After a Prolonged Endodontic Procedure: A Case Report.

CASE: In this article, we present a case report of a patient with limited medical history and without apparent local injury, who developed left hand Group A Streptococcus-induced necrotizing fasciitis after undergoing a prolonged endodontic procedure. CONCLUSION: In addition to host factors, perhaps, the virulence of the bacteria present in the oropharynx and the expected bacterial load based on the length and complexity of a dental procedure need to be considered when deciding on whether or not to administer prophylactic antibiotics to patients undergoing dental procedures.

The balance of muscle oxygen supply and demand reveals critical metabolic rate and predicts time to exhaustion.

We tested the hypothesis that during whole body exercise, the balance between muscle O2 supply and metabolic demand may elucidate intensity domains, reveal a critical metabolic rate, and predict time to exhaustion. Seventeen active, healthy volunteers (12 males, 5 females; 32 ± 2 yr) participated in two distinct protocols. Study 1 (n = 7) consisted of constant work rate cycling in the moderate, heavy, and severe exercise intensity domains with concurrent measures of pulmonary V̇o2 and local %SmO2 [via near-infrared spectroscopy (NIRS)] on quadriceps and forearm sites. Average %SmO2 at both sites displayed a domain-dependent response (P < 0.05). A negative %SmO2 slope was evident during severe-domain exercise but was positive during exercise below critical power (CP) at both muscle sites. In study 2 (n = 10), quadriceps and forearm site %SmO2 was measured during three continuous running trials to exhaustion and three intermittent intensity (ratio = 60 s severe: 30 s lower intensity) trials to exhaustion. Intensity-dependent negative %SmO2 slopes were observed for all trials (P < 0.05) and predicted zero slope at critical velocity. %SmO2 accurately predicted depletion and repletion of %D' balance on a second-by-second basis (R2 = 0.99, P < 0.05; both sites). Time to exhaustion predictions during continuous and intermittent exercise were either not different or better with %SmO2 [standard error of the estimate (SEE) < 20.52 s for quad, <44.03 s for forearm] versus running velocity (SEE < 65.76 s). Muscle O2 balance provides a dynamic physiological delineation between sustainable and unsustainable exercise (consistent with a "critical metabolic rate") and predicts real-time depletion and repletion of finite work capacity and time to exhaustion.NEW & NOTEWORTHY Dynamic muscle O2 saturation discriminates boundaries between exercise intensity domains, exposes a critical metabolic rate as the highest rate of steady state O2 supply and demand, describes time series depletion and repletion for work above critical power, and predicts time to exhaustion during severe domain whole body exercise. These results highlight the matching of O2 supply and demand as a primary determinant for sustainable exercise intensities from those that are unsustainable and lead to exhaustion.

Critical Velocity during Intermittent Running with Changes of Direction.

PURPOSE: We tested the hypothesis that critical velocity (CV) during intermittent running with changes of direction is reliably and accurately identified from a simple shuttle field test. We also tested the hypothesis that CV during intermittent running with changes of direction running is not equivalent to continuous linear running. METHODS: Young adults performed a custom shuttle test of intermittent sprint running to reveal CV. Sprints were 18.3 m per direction, with rest between sprints of 15 s for 3 min, 10 s for 2 min, and no rest for 2 min (7 min total). To test reliability, the CV shuttle test (CVST) was performed twice. To test validity, blood lactate was assessed during two separate trials inclusive of 5% above or below CVST end velocity. To explore task specificity, CV during CVST was compared to CV obtained from three linear running time trials. RESULTS: Total distance and CSVT end test velocity were similar between visits (864 ± 21 m and 3.23 ± 0.13 m·s vs 900 ± 30 m and 3.21 ± 0.15 m·s, respectively). At 5% above CVST end velocity, all subjects failed to complete 20 min and had unstable blood lactate values. A steady state blood lactate profile was observed during trials 5% below end velocity and all subjects completed the trial. The CV from the CVST was lower than the CV from linear running (△ -17% ± 6%), highlighting the importance of test specificity for threshold determination. CONCLUSIONS: The CVST provides a reliable and accurate determination of CV and can be used by coaches, athletes, and trainers to better understand the physiological impact specific to practice or competitions involving intermittent change of direction running.

Environmental Health Practice Challenges and Research Needs for U.S. Health Departments.

BACKGROUND: Environmental health (EH) professionals, one of the largest segments of the public health workforce, are responsible for delivery of essential environmental public health services. The challenges facing these professionals and research needs to improve EH practice are not fully understood, but 26% of EH professionals working in health departments of the United States plan to retire in 5 y, while only 6% of public health students are currently pursuing EH concentrations. OBJECTIVES: A groundbreaking initiative was recently launched to understand EH practice in health departments of the United States. This commentary article aims to identify priority EH practice challenges and related research needs for health departments. METHODS: A horizon scanning approach was conducted in which challenges facing EH professionals were provided by 1,736 respondents working at health departments who responded to a web-based survey fielded in November 2017. Thematic analyses of the responses and determining the frequency at which respondents reported specific issues and opportunities identified primary EH topic areas. These topic areas and related issues informed focus group discussions at an in-person workshop held in Anaheim, California. The purpose of the in-person workshop was to engage each of the topic areas and issues, through facilitated focus groups, leading to the formation of four to five related problem statements for each EH topic. DISCUSSION: EH professionals are strategically positioned to diagnose, intervene, and prevent public health threats. Focus group engagement resulted in 29 priority problem statements partitioned among 6 EH topic areas: a) drinking water quality, b) wastewater management, c) healthy homes, d) food safety, e) vectors and public health pests, and f) emerging issues. This commentary article identifies priority challenges and related research needs to catalyze effective delivery of essential environmental public health services for common EH program areas in health departments. An unprecedented initiative to revitalize EH practice with timely and strategic recommendations for student and professional training, nontraditional partnerships, and basic and translational research activities is recommended. https://doi.org/10.1289/EHP5161.

A gamma camera re-evaluation of potassium iodide blocking efficiency in mice.

The protection of the thyroid against radioiodine uptake has been an important safety concern for decades. After several studies examined potassium iodide blockade efficacy in the 1960's and 1970's, a standard dosage was prescribed by both the World Health Organization and the U.S. Food and Drug Administration. In this paper, we tested the effectiveness of a scaled version of that standard dosage in comparison to higher doses in mice. A novel gamma camera was employed with a high spatial resolution for precisely quantifying activity within the thyroid and a field of view large enough to image the entire mouse body. Thyroid and whole-body 125I biodistribution was analyzed immediately after exposure and 1 and 7 days later. It was found that 1 h after exposure five times the scaled human dose blocked thyroid uptake about 40% more effectively than the 1X scaled dose. Even after 1 d and 7 d, five times the recommended scaled human dose blocked approximately 10% more effectively than the 1X dose. These data suggest the need for continued evaluation of the effectiveness of KI as a blocking agent and the application of novel, non-invasive technologies to this important human health issue.

Low-dose niacin supplementation modulates GPR109A, niacin index and ameliorates Parkinson's disease symptoms without side effects.

A 65-year-old male, Parkinson's disease patient, was evaluated for GPR109A expression, niacin index, UPDRS scale, handwriting test, and quality of sleep with and without niacin treatment. The evaluation was repeated 3 months after niacin was stopped. Niacin modulated the abovementioned parameters and showed the overall improvement without side effects.

Upregulation of GPR109A in Parkinson's disease.

BACKGROUND: Anecdotal animal and human studies have implicated the symptomatic and neuroprotective roles of niacin in Parkinson's disease (PD). Niacin has a high affinity for GPR109A, an anti-inflammatory receptor. Niacin is also thought to be involved in the regulation of circadian rhythm. Here we evaluated the relationships among the receptor, niacin levels and EEG night-sleep in individuals with PD. METHODS AND FINDINGS: GPR109A expression (blood and brain), niacin index (NAD-NADP ratio) and cytokine markers (blood) were analyzed. Measures of night-sleep function (EEG) and perceived sleep quality (questionnaire) were assessed. We observed significant up-regulation of GPR109A expression in the blood as well as in the substantia nigra (SN) in the PD group compared to age-matched controls. Confocal microscopy demonstrated co-localization of GPR109A staining with microglia in PD SN. Pro and anti-inflammatory cytokines did not show significant differences between the groups; however IL1-ß, IL-4 and IL-7 showed an upward trend in PD. Time to sleep (sleep latency), EEG REM and sleep efficiency were different between PD and age-matched controls. Niacin levels were lower in PD and were associated with increased frequency of experiencing body pain and decreased duration of deep sleep. CONCLUSIONS: The findings of associations among the GPR109A receptor, niacin levels and night-sleep function in individuals with PD are novel. Further studies are needed to understand the pathophysiological mechanisms of action of niacin, GPR109A expression and their associations with night-sleep function. It would be also crucial to study GPR109A expression in neurons, astrocytes, and microglia in PD. A clinical trial to determine the symptomatic and/or neuroprotective effect of niacin supplementation is warranted.

Low dose Hsp90 inhibitor 17AAG protects neural progenitor cells from ischemia induced death.

Stress adaptation effect provides cell protection against ischemia induced apoptosis. Whether this mechanism prevents other types of cell death in stroke is not well studied. This is an important question for regenerative medicine to treat stroke since other types of cell death such as necrosis are also prominent in the stroke brain apart from apoptosis. We report here that treatment with 17-N-Allylamino-17-demethoxygeldanamycin (17AAG), an Hsp90 inhibitor, protected neural progenitor cells (NPCs) against oxygen glucose deprivation (OGD) induced cell death in a dose dependent fashion. Cell death assays indicated that 17AAG not only ameliorated apoptosis, but also necrosis mediated by OGD. This NPC protection was confirmed by exposing cells to oxidative stress, a major stress signal prevalent in the stroke brain. Mechanistic studies demonstrated that 17AAG activated PI3K/Akt and MAPK cell protective pathways. More interestingly, these two pathways were activated in vivo by 17AAG and 17AAG treatment reduced infarct volume in a middle cerebral artery occlusion (MCAO) stroke model. These data suggest that 17AAG protects cells against major cell death pathways and thus might be used as a pharmacological conditioning agent for regenerative medicine for stroke.

Lifelong exposure to methylmercury disrupts stress-induced corticosterone response in zebra finches (Taeniopygia guttata).

Mercury can disrupt the endocrine systems of mammals and fish, but little is known about its effects on avian hormones. The authors employed an experimental manipulation to show that methylmercury suppresses the stress-induced corticosterone response in birds, an effect previously unreported in the literature. Corticosterone regulates many normal metabolic processes, such as the maintenance of proper blood glucose levels during stressful daily fasting; an inability to increase corticosterone levels in response to stressors renders a bird less able to face a wide array of environmental challenges. The authors studied reproductively mature zebra finches that had been exposed to 0.0 µg/g, 0.3 µg/g, 0.6 µg/g, 1.2 µg/g, or 2.4 µg/g (wet wt) dietary methylmercury throughout their life (i.e., from the egg onward). In contrast to some field studies, the present study found no significant change in baseline plasma corticosterone concentrations attributable to chronic methylmercury exposure. However, a comparison between the baseline corticosterone levels and levels after 30 min of handling stress revealed that the ability of birds to mount a stress response was reduced with increasing blood total mercury concentration. These results are consistent with adrenal corticoid disruption caused by chronic mercury exposure and mirror a similar study on free-living nestling songbirds exposed to environmental mercury.

Critical role of Spns2, a sphingosine-1-phosphate transporter, in lung cancer cell survival and migration.

The sphingosine-1-phosphate (S1P) transporter Spns2 regulates myocardial precursor migration in zebrafish and lymphocyte trafficking in mice. However, its function in cancer has not been investigated. We show here that ectopic Spns2 expression induced apoptosis and its knockdown enhanced cell migration in non-small cell lung cancer (NSCLC) cells. Metabolically, Spns2 expression increased the extracellular S1P level while its knockdown the intracellular. Pharmacological inhibition of S1P synthesis abolished the augmented cell migration mediated by Spns2 knockdown, indicating that intracellular S1P plays a key role in this process. Cell signaling studies indicated that Spns2 expression impaired GSK-3ß and Stat3 mediated pro-survival pathways. Conversely, these pathways were activated by Spns2 knockdown, which explains the increased cell migration since they are also crucial for migration. Alterations of Spns2 were found to affect several enzymes involved in S1P metabolism, including sphingosine kinases, S1P phosphatases, and S1P lyase 1. Genetically, Spns2 mRNA level was found to be reduced in advanced lung cancer (LC) patients as quantified by using a small scale qPCR array. These data show for the first time that Spns2 plays key roles in regulating the cellular functions in NSCLC cells, and that its down-regulation is a potential risk factor for LC.

Real-time immune monitoring to guide plasmid DNA vaccination schedule targeting prostatic acid phosphatase in patients with castration-resistant prostate cancer.

PURPOSE: We have previously reported that a DNA vaccine encoding prostatic acid phosphatase (PAP) could elicit PAP-specific T cells in patients with early recurrent prostate cancer. In the current pilot trial, we sought to evaluate whether prolonged immunization with regular booster immunizations, or "personalized" schedules of immunization determined using real-time immune monitoring, could elicit persistent, antigen-specific T cells, and whether treatment was associated with changes in PSA doubling time (PSA DT). EXPERIMENTAL DESIGN: Sixteen patients with castration-resistant, nonmetastatic prostate cancer received six immunizations at 2-week intervals and then either quarterly (arm 1) or as determined by multiparameter immune monitoring (arm 2). RESULTS: Patients were on study a median of 16 months; four received 24 vaccinations. Only one event associated with treatment >grade 2 was observed. Six of 16 (38%) remained metastasis-free at 2 years. PAP-specific T cells were elicited in 12 of 16 (75%), predominantly of a Th1 phenotype, which persisted in frequency and phenotype for at least 1 year. IFNγ-secreting T-cell responses measured by ELISPOT were detectable in 5 of 13 individuals at 1 year, and this was not statistically different between study arms. The overall median fold change in PSA DT from pretreatment to posttreatment was 1.6 (range, 0.6-7.0; P = 0.036). CONCLUSIONS: Repetitive immunization with a plasmid DNA vaccine was safe and elicited Th1-biased antigen-specific T cells that persisted over time. Modifications in the immunization schedule based on real-time immune monitoring did not increase the frequency of patients developing effector and memory T-cell responses with this DNA vaccine.

A small-animal imaging system capable of multipinhole circular/helical SPECT and parallel-hole SPECT.

We have designed and built a small animal single photon emission computed tomography (SPECT) imaging system equipped with parallel-hole and multipinhole collimators and capable of circular or helical SPECT. Copper-beryllium parallel-hole collimators suitable for imaging the ~35 keV photons from the decay of (125)I have been built and installed to achieve useful spatial resolution over a range of object-detector distances and to reduce imaging time on our dual-detector array. To address the resolution limitations in the parallel-hole SPECT and the sensitivity and limited field of view of single-pinhole SPECT, we have incorporated multipinhole circular and helical SPECT in addition to expanding the parallel-hole SPECT capabilities. The pinhole SPECT system is based on a 110 mm diameter circular detector equipped with a pixellated NaI(Tl) scintillator array (1x1x5 mm(3)/pixel). The helical trajectory is accomplished by two stepping motors controlling the rotation of the detector-support gantry and displacement of the animal bed along the axis of rotation of the gantry. Results obtained in SPECT studies of various phantoms show an enlarged field of view, very good resolution and improved sensitivity using multipinhole circular or helical SPECT. Collimators with one, three and five 1 mm diameter pinholes have been implemented and compared in these tests. Our objective is to develop a system on which one may readily select a suitable mode of either parallel-hole SPECT or pinhole circular or helical SPECT for a variety of small animal imaging applications.

Adrenal gland differences associated with puberty and reproductive inhibition in Peromyscus maniculatus.

Laboratory populations of the prairie deermouse (Peromyscus maniculatus) reach a growth asymptote due primarily to the failure of more than 90% of the young born into the population to mature sexually. This inhibition is reversible; when young are removed from the inhibiting influence of the population more than 75% will reproduce within 80 days of pairing. Interestingly, the mechanism of this inhibition does not involve the degree of adrenal hypertrophy as reported in rats and housemice. We report here that the adrenal morphology of reproductively inhibited deermice raised within laboratory populations is different from patterns seen with normal puberty; namely in the area, histology, and apparent activity of the weak androgen-secreting zona reticularis. Our data indicate that the frequency of adrenal cortex cellular apoptosis is not different between the adrenal zones or between reproductively capable versus inhibited animals and therefore does not account for the differences in the numbers of cells with pycnotic nuclei in the zona reticularis of inhibited animals. We also found that the concentration of serum DHEA is significantly reduced in reproductively inhibited animals suggesting that the zona reticularis of inhibited animals may be less active than in controls. We present data to indicate that the adrenal zona reticularis of 30-day-old control animals is likely to be more active than reproductively inhibited animals of the same age. Our data also indicate that older reproductively inhibited animals of both sexes are also likely to have a much less active zona reticularis. These differences may be implicated in the mechanism of reproductive inhibition.