Possible utilization of salivary IFN-γ/IL-4 ratio as a marker of chronic stress in healthy individuals

Stress and sleep deprivation-related biomarkers in saliva in patients with retinitis pigmentosa

PURPOSE

Patients with Retinitis Pigmentosa (RP) commonly experience sleep-related issues and are susceptible to stress. Moreover, variatiaons in their vision are often linked to anxiety, stress and drowsiness, indicating that stress and sleep deprivation lead to a decline in vision, and vision improves when both are mitigated. The objective of this study was to investigate the utility of salivary biomarkers as biochemical indicators of anxiety and sleep deprivation in RP patients.

METHODS

Seventy-eight RP patients and 34 healthy controls were included in this observational study. Anxiety and sleep-quality questionnaires, a complete ophthalmological exam for severity grading and, the collection of salivary samples from participants were assessed for participants. The activity of biomarkers was estimated by ELISA, and statistical analysis was performed to determine associations between the parameters. Associations between underlying psychological factors, grade of disease severity, and biomarkers activity were also examined.

RESULTS

Fifty-two (67%) of patients had a severe RP, and 26 (33%) had a mild-moderate grade. Fifty-eight (58,9%) patients reported severe levels of anxiety and 18 (23.,1%) a high level. Forty-six (59%) patients obtained pathological values in sleep-quality questionaries and 43 (55.1%) in sleepiness. Patients with RP exhibited significant differences in testosterone, cortisol, sTNFαRII, sIgA and melatonin as compared to controls and patients with a mild-moderate and advanced stage of disease showed greater differences. In covariate analysis, patients with a severe anxiety level also showed greater differences in mean salivary cortisol, sTNFαRII and melatonin and male patients showed lower IgA levels than female.

CONCLUSIONS

The present findings suggest that salivary biomarkers could be suitable non-invasive biochemical markers for the objective assessment of sleep deprivation and anxiety in RP patients. Further research is needed to characterize the effects of untreated negative psychological states and sleep deprivation on increased variability of vision and disease progression, if any.

The race-based stress reduction intervention (RiSE) study on African American women in NYC and Chicago: Design and methods for complex genomic analysis

RiSE study aims to evaluate a race-based stress-reduction intervention as an effective strategy to improve coping and decrease stress-related symptoms, inflammatory burden, and modify DNA methylation of stress response-related genes in older AA women. This article will describe genomic analytic methods to be utilized in this longitudinal, randomized clinical trial of older adult AA women in Chicago and NYC that examines the effect of the RiSE intervention on DNAm pre- and post-intervention, and its overall influence on inflammatory burden. Salivary DNAm will be measured at baseline and 6 months following the intervention, using the Oragene-DNA kit. Measures of perceived stress, depressive symptoms, fatigue, sleep, inflammatory burden, and coping strategies will be assessed at 4 time points including at baseline, 4 weeks, 8 weeks, and 6 months. Genomic data analysis will include the use of pre-processed and quality-controlled methylation data expressed as beta (β) values. Association analyses will be performed to detect differentially methylated sites on the targeted candidate genes between the intervention and non-intervention groups using the Δβ (changes in methylation) with adjustment for age, health behaviors, early life adversity, hybridization batch, and top principal components of the probes as covariates. To account for multiple testing, we will use FDR adjustment with a corrected p-value of <0.05 regarded as statistically significant. To assess the relationship between inflammatory burden and Δβ among the study samples, we will repeat association analyses with the inclusion of individual inflammation protein measures. ANCOVA will be used because it is more statistically powerful to detect differences.

Salivary signatures of oral-brain communication in sleep bruxers

Introduction

Microbiota and their interaction with hosts have been of great interest in brain research in recent years. However, the role of oral microbiota in mental illness and the underlying mechanism of oral-brain communication remains elusive. Sleep bruxism (SB) is an oral parafunctional activity related to the nervous system and is considered a risk factor for harmful clinical consequences and severe systemic conditions. Exploring the connection between oral microbiota and sleep bruxism may deepen our understanding of the complex relationship between oral-brain axis and provide insights for treatment.

Methods

In this study, salivary samples were collected from 22 individuals with SB and 21 healthy controls, and metagenomics with metabolomics was performed. Nonparametric Wilcoxon test were applied for the statistical analysis between the two groups. Microbial dysbiosis and altered oral metabolites were found in the SB individuals.

Results

The characteristic metabolite N-acetylglucosamine (GlcNAc) (VIP=8.4823, P<0.05) was correlated to a statistically lower Streptococcus mitis level in SB individuals. Salivary IFN-g level and IFN-g/IL-4 ratio were detected with significant changes in a chip assay. Amino acid metabolism pathways were upregulated, and the pathway with the largest number of differentially expressed genes is related to amino-tRNA charging pathway, while the most significantly enriched pathway is related to arginine biosynthesis. Neurotransmitter-associated pathways with glutamatergic and GABAergic synapses and cardiovascular system-related pathways were enriched in the SB group.

Discussion

These results indicate a possible neuroimmune regulatory network of oral-brain communication in SB, which helps explain the mechanism of the oral microbiome with the host in sleep bruxers and provides a reference for early clinical and therapeutic intervention to improve the diagnosis and treatment of SB and similar diseases.

The impact of perceived stress on the hair follicle: Towards solving a psychoneuroendocrine and neuroimmunological puzzle

While popular belief harbors little doubt that perceived stress can cause hair loss and premature graying, the scientific evidence for this is arguably much thinner. Here, we investigate whether these phenomena are real, and show that the cyclic growth and pigmentation of the hair follicle (HF) provides a tractable model system for dissecting how perceived stress modulates aspects of human physiology. Local production of stress-associated neurohormones and neurotrophins coalesces with neurotransmitters and neuropeptides released from HF-associated sensory and autonomic nerve endings, forming a complex local stress-response system that regulates perifollicular neurogenic inflammation, interacts with the HF microbiome and controls mitochondrial function. This local system integrates into the central stress response systems, allowing the study of systemic stress responses affecting organ function by quantifying stress mediator content of hair. Focusing on selected mediators in this "brain-HF axis" under stress conditions, we distill general principles of HF dysfunction induced by perceived stress.

Possible utilization of salivary IFN-γ/IL-4 ratio as a marker of chronic stress in healthy individuals

Introduction

Several studies show that psychological stress reduces Th1/Th2 ratio in blood samples. However, evidence is scarce regarding the cytokine alterations during stress in saliva. We investigated the influence of chronic stress on Th1/Th2 ratio and cytokine profiles in the saliva of healthy individuals. Further, we examined the associations of the salivary cytokine levels with sleep and attention problems, which are closely related with psychological stress.

Methods

Salivary levels of 27 cytokines were measured by multiplex bead array assays in 31 healthy young individuals (health science students and hospital staff consisting of 11 men and 20 women, mean age [standard deviation] =21.5 [0.8] years). The Kessler Psychological Distress scale (K10) and Athens Insomnia Scale (AIS) were administered to assess subjective chronic psychological stress and sleep problems. Further, participants were asked to wear Actigraph GT3X accelerometers for 3 days to assess the total sleep time. Attention problems were assessed by administering the Integrated Visual and Auditory Continuous Performance Test (IVA‐CPT).

Results

Thirteen cytokines with >80% detectable results were included in the main analyses. The IFN‐γ/IL‐4 ratio, which is a commonly used index for Th1/Th2 ratio, showed significant negative correlations with the K10 and AIS scores. None of the cytokines were significantly associated with sex, body mass index, sleep index measured by Actigraph, or IVA‐CPT scores.

Conclusion

Chronic stress may be associated with alterations of the Th1/Th2 balance in salivary cytokine production. IFN‐γ/IL‐4 ratio in saliva may serve as a potential biomarker of chronic stress in healthy individuals.

The present study investigated the influence of chronic stress on Th1/Th2 ratio and cytokine profiles in the saliva of healthy individuals. The IFN‐γ/IL‐4 ratio showed a significant negative correlation with chronic stress, assessed by the Kessler Psychological Distress scale. IFN‐γ/IL‐4 ratio in saliva may serve as a potential biomarker of chronic stress in healthy individuals.