Stress and gene expression of individuals with chronic abdominal pain

Eating Behavior, Stress, and Adiposity: Discordance Between Perception and Physiology

The purpose of the study was to examine the interrelationships among stress, eating behavior, and adiposity in a cohort of normal- and overweight individuals. Clinical markers of physiological stress (fasting serum cortisol) and adiposity (body mass index [BMI] and percent body fat) were obtained from participants selected for a natural history protocol ( n = 107). Self-reported data on eating behavior (using the Three-Factor Eating Questionnaire subscales such as Cognitive Restraint, Disinhibition, and Hunger) and psychological stress (via the Perceived Stress Scale) were evaluated. Demographic information was incorporated using principal component analysis, which revealed sex- and weight-based differences in stress, adiposity, and eating behavior measures. Following a cross-sectional and descriptive analysis, significant correlations were found between the Disinhibition and Hunger eating behavior subscales and measures of adiposity including BMI ( r = .30, p = .002 and r = .20, p = .036, respectively) and percent body fat ( r = .43, p = .000 and r = .22, p = .022, respectively). Relationships between stress measures and eating behavior were also evident in the analysis. Disinhibition and Hunger correlated positively with perceived stress ( r = .32, p .001 and r = .26, p = .008, respectively). However, Disinhibition varied inversely with serum cortisol levels ( r = -.25, p = .009). Future studies are warranted to better understand this paradox underlying the effects of perceived and physiological stress on eating behavior.

Lysozyme association with circulating RNA, extracellular vesicles, and chronic stress

BACKGROUND

Stress has demonstrated effects on inflammation though underlying cell-cell communication mechanisms remain unclear. We hypothesize that circulating RNAs and extracellular vesicles (EVs) in patients with chronic stress contain signals with functional roles in cell repair.

METHODS

Blood transcriptome from patients with Irritable Bowel Syndrome versus controls were compared to identify signaling pathways and effectors. Plasma EVs were isolated (size-exclusion chromatography) and characterized for effectors' presence (immunogold labelling-electron microscopy). Based on transcriptome pathways and EV-labelling, lysozyme's effects on cell migration were tested in human colon epithelial CRL-1790 cells and compared to the effects of CXCL12, a migration inducer (wound assay). The effect of lysozyme on immune-linked mRNA and protein levels in cells which survived following serum starvation and scratch wound were investigated (NanoString).

RESULTS

Blood transcriptomes revealed pyridoxal 5'phosphate salvage, pyrimidine ribonucleotides salvage pathways, atherosclerosis, and cell movement signaling with membrane CD9 and extracellular lysozyme as effectors. Plasma EVs showed labelling with CD9, mucins, and lysozyme. This is the first identification of lysozyme on plasma EVs. In CRL-1790 cells, lysozyme induced migration and repaired scratch wound as well as CXCL12. Immune mRNA and protein expressions were altered in cells which survived following serum starvation and scratch wound, with or without lysozyme in serum-free media post-wounding: CD9, IL8, IL6 mRNAs and CD9, NT5E, PD-L1 proteins.

CONCLUSIONS

Repair and inflammatory signals are identified in plasma EVs and circulating RNAs in chronic stress. Registered clinicaltrials.gov #NCT00824941.

GENERAL SIGNIFICANCE

This study highlights the role of circulating RNAs and EVs in stress.

Anti-Müllerian Hormone Levels and Urinary Cortisol in Women With Chronic Abdominal Pain

OBJECTIVE

To explore the association of hypothalamic-pituitary-adrenal activity with ovarian functioning in women with and without chronic abdominal pain (CAP).

DESIGN AND SETTING

A secondary data analysis was performed with data from female participants in a natural history protocol at the National Institutes of Health.

PARTICIPANTS

A total of 36 women (age range = 19-39 years, mean = 27.11 years) were included in the study.

METHODS

This pilot study was conducted with a subset of participants enrolled in a natural history protocol conducted in the Hatfield Clinical Research Center at the National Institutes of Health. The parent study included participants with and without CAP who provided a 5-hour urine sample for determination of cortisol levels and serum samples for determination of circulating levels of cortisol, luteinizing hormone, and follicle-stimulating hormone. CAP was defined as presence or absence of chronic pain for at least 6 months and was determined via self-report.

RESULTS

Anti-Müllerian hormone (AMH) concentrations declined significantly with age as expected. When AMH levels were dichotomized as normal or abnormal (defined as higher or lower than age-specific normative ranges, respectively), there were significant associations between abnormal AMH levels and CAP and urine cortisol levels. Participants with CAP or low urine cortisol levels were significantly more likely to have abnormal AMH levels.

CONCLUSION

Results suggest that chronic abdominal pain and hypothalamic-pituitary-adrenal dysregulation may be associated with abnormal AMH levels.

Inflammatory genes and psychological factors predict induced shoulder pain phenotype

PURPOSE

The pain experience has multiple influences, but little is known about how specific biological and psychological factors interact to influence pain responses. The current study investigated the combined influences of genetic (pro-inflammatory) and psychological factors on several preclinical shoulder pain phenotypes.

METHODS

An exercise-induced shoulder injury model was used, and a priori selected genetic (IL1B, TNF/LTA region, and IL6 single nucleotide polymorphisms (SNP)) and psychological (anxiety, depression symptoms, pain catastrophizing, fear of pain, and kinesiophobia) factors were included as the predictors of interest. The phenotypes were pain intensity (5-d average and peak reported on numerical rating scale), upper extremity disability (5-d average and peak reported on the Quick Disabilities of the Arm, Shoulder and Hand instrument), and duration of shoulder pain (d).

RESULTS

After controlling for age, sex, and race, the genetic and psychological predictors were entered separately as main effects and interaction terms in regression models for each pain phenotype. Results from the recruited cohort (n = 190) indicated strong statistical evidence for the interactions between 1) TNF/LTA SNP rs2229094 and depression symptoms for average pain intensity and duration and 2) IL1B two SNP diplotype and kinesiophobia for average shoulder pain intensity. Moderate statistical evidence for prediction of additional shoulder pain phenotypes included interactions of kinesiophobia, fear of pain, or depressive symptoms with TNF/LTA rs2229094 and IL1B.

CONCLUSIONS

These findings support the combined predictive ability of specific genetic and psychological factors for shoulder pain phenotypes by revealing novel combinations that may merit further investigation in clinical cohorts to determine their involvement in the transition from acute to chronic pain conditions.