Hypothalamic-Pituitary-Adrenal Axis Response in Patients With Acne Vulgaris Treated With Clascoterone.

BACKGROUND: Clascoterone cream 1% is a topical androgen receptor inhibitor approved to treat acne vulgaris in patients =>12 years of age. This report provides details of patients who developed laboratory signs of hypothalamic-pituitary-adrenal (HPA) axis suppression without clinical signs of adrenal suppression during the clascoterone development program. METHODS: Two open-label, multicenter, Phase 2 trials evaluated HPA axis suppression in patients with moderate-to-severe acne vulgaris. Study 1 (NCT01831960) enrolled cohorts of adults =>18 years of age and adolescents =>12 to <18 years of age. Study 2 (NCT02720627) enrolled adolescents 9 to <12 years of age. Patients applied clascoterone twice daily at maximum-exposure dosages for 14 days. Adrenal suppression was evaluated via cosyntropin stimulation test (CST) at baseline and day 14. Patients with an abnormal CST result (serum cortisol level =<18 µg/dL) had a follow-up CST approximately 4 weeks later. Blood was collected for pharmacokinetic analysis. Other safety assessments included adverse events (AEs), physical examination/vital signs, and electrocardiography. RESULTS: Overall, 5/69 clascoterone-treated patients had an abnormal CST result on day 14, including 1/20 adults, 2/22 patients aged =>12 to <18 years, and 2/27 patients aged 9 to <12 years. All patients had normal cortisol levels at follow-up testing approximately 4 weeks later. No relationship was observed between abnormal CST results and clascoterone plasma concentrations or the amount of study drug applied. No clinically relevant AEs or clinically significant changes in safety measures were observed in patients with adrenal suppression. CONCLUSION: Clascoterone induced laboratory evidence of mild, reversible HPA axis suppression under maximum-use exposure. J Drugs Dermatol. 2024;23(6):433-437.     doi:10.36849/JDD.7997.

Exogenous melatonin's effect on salivary cortisol and amylase: A randomized controlled trial.

This study aimed to examine the effect of acute exogenous melatonin administration on salivary cortisol and alpha-amylase (sCort and sAA) as representatives of the HPA axis and the sympathetic nervous system, respectively. A single-dose prolonged-release melatonin (2 mg) or a placebo tablet was given to healthy volunteers (n = 64) at 20:00 h in a crossover design. The saliva was collected at six time points (20:00, 21:00, awakening, 30 min after awakening, 10:00, and 12:00 h) and was measured for sCort, sAA, and salivary melatonin (sMT) levels. Pulse rates and sleep parameters were also collected. Melatonin was effective in improving sleep onset latency by 7:04 min (p = .037) and increasing total sleep time by 24 min (p = .006). Participants with poor baseline sleep quality responded more strongly to melatonin than participants with normal baseline sleep quality as they reported more satisfaction in having adequate sleep (p = .017). Melatonin administration resulted in higher sCort levels at awakening time point (p = .023) and a tendency of lower sAA levels but these were not significant. Melatonin ingestion at 20:00 h resulted in a marked increase in sMT levels at 21:00 h and remained higher than baseline up to at least 10:00 h (p < .001). Melatonin increases sCort levels at certain time point with a tendency to lower sAA levels. These opposing effects of melatonin suggested a complex interplay between melatonin and these biomarkers. Also, the results confirmed the positive acute effect of a single-dose melatonin on sleep quality.

Effects of Withania somnifera Extract in Chronically Stressed Adults: A Randomized Controlled Trial.

BACKGROUND: Stress is a known causative factor in modulating cognitive health, which overall well-being and quality of life are dependent on. Long-term stress has been shown to disrupt the balance of the hypothalamic-pituitary-adrenal (HPA) axis. Adaptogens, such as Withania somnifera (ashwagandha), are commonly used in Ayurvedic medicine for stress relief and ameliorating HPA-axis dysfunction. The aim of this study was to support the role of a root and leaf water-extracted ashwagandha extract (WS) in stress reduction by confirming the lowest clinically validated dose for stress management (125 mg/day) in a dose-dependent clinical study in adults with self-reported high stress. METHODS: An 8-week, randomized, double-blinded, placebo-controlled study to compare the effects of three different WS extract doses (125, 250 and 500 mg) was performed. A total of 131 adults were enrolled, and 98 were included in the final analysis. Attenuation of chronic stress was measured using the 14-item Perceived Stress Scale (PSS) and biochemical-related stress parameters. RESULTS: We have shown that aqueous WS extract (roots and leaves) safely reduces mild to moderate chronic stress at doses of 125 mg, 250 mg, and 500 mg/day for 8 weeks. CONCLUSIONS: Our findings demonstrate the stress-reduction capabilities of this well-characterized aqueous extract of WS (root and leaf) at the low dose of 125 mg/day, in a dose-dependent manner, via the modulation of the HPA axis. TRIAL REGISTRATION: This study was registered with the Clinical Trials Registry-India (CTRI) with the registration number: CTRI/2019/11/022100.

Corticosterone release in very young siblicidal seabird chicks (Rissa tridactyla) is sensitive to environmental variability and responds rapidly and robustly to external challenges.

In birds, patterns of development of the adrenocortical response to stressors vary among individuals, types of stressors, and species. Since there are benefits and costs of exposure to elevated glucocorticoids, this variation is presumably a product of selection such that animals modulate glucocorticoid secretion in contexts where doing so increases their fitness. In this study, we evaluated hypothalamo-pituitary-adrenal (HPA) activity in first-hatched free-living seabird nestlings that engage in intense sibling competition and facultative siblicide (black-legged kittiwakes, Rissa tridactyla). We sampled 5 day old chicks (of the ∼45 day nestling period), a critical early age when food availability drives establishment of important parent-offspring and intra-brood dynamics. We experimentally supplemented parents with food ("supplemented") and measured chick baseline corticosterone secretion and capacity to rapidly increase corticosterone in response to an acute challenge (handling and 15 min of restraint in a bag). We also used topical administration of corticosterone to evaluate the ability of chicks to downregulate physiologically relevant corticosterone levels on a short time scale (minutes). We found that 5 day old chicks are not hypo-responsive but release corticosterone in proportion to the magnitude of the challenge, showing differences in baseline between parental feeding treatments (supplemented vs non-supplemented), moderate increases in response to handling, and a larger response to restraint (comparable to adults) that also differed between chicks from supplemented and control nests. Topical application of exogenous corticosterone increased circulating levels nearly to restraint-induced levels and induced downregulation of HPA responsiveness to the acute challenge of handling. Parental supplemental feeding did not affect absorbance/clearance or negative feedback. Thus, while endogenous secretion of corticosterone in young chicks is sensitive to environmental context, other aspects of the HPA function, such as rapid negative feedback and/or the ability to clear acute elevations in corticosterone, are not. We conclude that 5 day old kittiwake chicks are capable of robust adrenocortical responses to novel challenges, and are sensitive to parental food availability, which may be transduced behaviorally, nutritionally, or via maternal effects. Questions remain about the function of such rapid, large acute stress-induced increases in corticosterone in very young chicks.

Optogenetic induction of chronic glucocorticoid exposure in early-life leads to blunted stress-response in larval zebrafish.

Early life stress (ELS) exposure alters stress susceptibility in later life and affects vulnerability to stress-related disorders, but how ELS changes the long-lasting responsiveness of the stress system is not well understood. Zebrafish provides an opportunity to study conserved mechanisms underlying the development and function of the stress response that is regulated largely by the neuroendocrine hypothalamus-pituitary-adrenal/interrenal (HPA/I) axis, with glucocorticoids (GC) as the final effector. In this study, we established a method to chronically elevate endogenous GC levels during early life in larval zebrafish. To this end, we employed an optogenetic actuator, beggiatoa photoactivated adenylyl cyclase, specifically expressed in the interrenal cells of zebrafish and demonstrate that its chronic activation leads to hypercortisolaemia and dampens the acute-stress evoked cortisol levels, across a variety of stressor modalities during early life. This blunting of stress-response was conserved in ontogeny at a later developmental stage. Furthermore, we observe a strong reduction of proopiomelanocortin (pomc)-expression in the pituitary as well as upregulation of fkbp5 gene expression. Going forward, we propose that this model can be leveraged to tease apart the mechanisms underlying developmental programming of the HPA/I axis by early-life GC exposure and its implications for vulnerability and resilience to stress in adulthood.

Neurobehavioral and molecular changes in a rodent model of ACTH-induced HPA axis dysfunction.

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation is linked to the pathophysiology of depression. Although exogenous adrenocorticotropic hormone (ACTH) is associated with a depressive-like phenotype in rodents, comprehensive neurobehavioral and mechanistic evidence to support these findings are limited. Sprague-Dawley rats (male, n = 30; female, n = 10) were randomly assigned to the control (male, n = 10) or ACTH (male, n = 20; female n = 10) groups that received saline (0.1 ml, sc.) or ACTH (100 µg/day, sc.), respectively, for two weeks. Thereafter, rats in the ACTH group were subdivided to receive ACTH plus saline (ACTH_S; male, n = 10; female, n = 5; 0.2 ml, ip.) or ACTH plus imipramine (ACTH_I; male, n = 10; female, n = 5;10 mg/kg, ip.) for a further four weeks. Neurobehavioral changes were assessed using the forced swim test (FST), the sucrose preference test (SPT), and the open field test (OFT). Following termination, the brain regional mRNA expression of BDNF and CREB was determined using RT-PCR. After two-weeks, ACTH administration significantly increased immobility in the FST (p = 0.03), decreased interaction with the center of the OFT (p < 0.01), and increased sucrose consumption (p = 0.03) in male, but not female rats. ACTH administration significantly increased the expression of BDNF in the hippocampus and CREB in all brain regions in males (p < 0.05), but not in female rats. Imipramine treatment did not ameliorate these ACTH-induced neurobehavioral or molecular changes. In conclusion, ACTH administration resulted in a sex-specific onset of depressive-like symptoms and changes in brain regional expression of neurotrophic factors. These results suggest sex-specific mechanisms underlying the development of depressive-like behavior in a model of ACTH-induced HPA axis dysregulation.

Impact of Long-Term Dietary High Fat and Eicosapentaenoic Acid on Behavior and Hypothalamic-Pituitary-Adrenal Axis Activity in Amyloidogenic APPswe/PSEN1dE9 Mice.

INTRODUCTION: Alzheimer's disease (AD) alters neurocognitive and emotional function and causes dysregulation of multiple homeostatic processes. The leading AD framework pins amyloid beta plaques and tau tangles as primary drivers of dysfunction. However, many additional variables, including diet, stress, sex, age, and pain tolerance, interact in ways that are not fully understood to impact the onset and progression of AD pathophysiology. We asked: (1) does high-fat diet, compared to low-fat diet, exacerbate AD pathophysiology and behavioral decline? And, (2) can supplementation with eicosapentaenoic (EPA)-enriched fish oil prevent high-fat-diet-induced changes? METHODS: Male and female APPswePSdE9 mice, and their non-transgenic littermates, were randomly assigned to a diet condition (low-fat, high-fat, high-fat with EPA) and followed from 2 to 10 months of age. We assessed baseline corticosterone concentration during aging, pain tolerance, cognitive function, stress coping, and corticosterone response to a stressor. RESULTS: Transgenic mice were consistently more active than non-transgenic mice but did not perform worse on either cognitive task, even though we recently reported that these same transgenic mice exhibited metabolic changes and had increased amyloid beta. Mice fed high-fat diet had higher baseline and post-stressor corticosterone, but diet did not impact cognition or pain tolerance. Sex had the biggest influence, as female mice were consistently more active and had higher corticosterone than males. CONCLUSION: Overall, diet, genotype, and sex did not have consistent impacts on outcomes. We found little support for predicted interactions and correlations, suggesting diet impacts metabolic function and amyloid beta levels, but these outcomes do not translate to changes in behaviors measured here.

Pterostilbene alleviates cafeteria diet-induced obesity and underlying depression in adolescent male Swiss albino mice and affects insulin resistance, inflammation, HPA axis dysfunction and SIRT1 mediated leptin-ghrelin signaling.

Cafeteria diet (CD) model for in-vivo studies mimics the western diet having imbalanced nutritional value, high caloric-density and palatability. Uncontrolled eating leads to the development of childhood obesity, poor self-esteem and depression due to its effects on brain development. Herbal supplements are novel inclusion in the management of obesity and mental well-being. Pterostilbene (PTE) found in blueberries and Pterocarpus marsupium heartwood, is known to prevent obesity in invivo models. Adolescent Swiss albino male mice were fed on CD for 70 days and the development of obesity was assessed by gain in body weight, abdominal circumference. Forced swim and tail suspension test confirmed depression in CD fed mice. Obesity induced depressed (OID) mice were treated with PTE (10, 20, 40 mg/kg), standard antiobesity drug cetilistat (10 mg/kg), antidepressant fluoxetine (10 mg/kg) for 28 days. Post treatment, PTE-treated mice showed reduction in BW and depression-like behavior analysed using paradigms such as sucrose preference, open field, marble burying, and resident intruder test in comparison to the CD group. Insulin resistance, lipid profile, antioxidant enzyme, inflammatory cytokines (NF-κB, IL-6, TNF α) and cortisol levels were mitigated by PTE. It also restored normal cellular architecture of the brain and adipose tissue and increased the Silent mating type information regulation 2 homolog1 (SIRT1), leptin and ghrelin receptors gene expression in the brain. Thus, it can be concluded that PTE might have inhibited OID like behavior in mice via inhibition of IR, modulating neuroinflammation and hypothalamic-pituitary-adrenal axis dysfunction and upregulating SIRT1 mediated leptin-ghrelin signaling.

Prenatal serotonin reuptake inhibitor antidepressant exposure, SLC6A4 genetic variations, and cortisol activity in 6-year-old children of depressed mothers: A cohort study.

Prenatal exposure to maternal depression and serotonin reuptake inhibitor (SRI) antidepressants both affect the development of the hypothalamic-pituitary-adrenal (HPA) system, possibly via the neurotransmitter serotonin (5HT). In a community cohort, we investigated the impact of two factors that shape prenatal 5HT signaling (prenatal SRI [pSRI] exposure and child SLC6A4 genotype) on HPA activity at age 6 years. Generalized estimating equation (GEE) models were used to study associations between cortisol reactivity, pSRI exposure, and child SLC6A4 genotype, controlling for maternal depression, child age, and sex (48 pSRI exposed, 74 nonexposed). Salivary cortisol levels were obtained at five time points during a laboratory stress challenge: arrival at the laboratory, following two sequential developmental assessments, and then 20 and 40 min following the onset of a stress-inducing cognitive/social task. Cortisol decreased from arrival across both developmental assessments, and then increased across both time points following the stress challenge in both groups. pSRI-exposed children had lower cortisol levels across all time points. In a separate GEE model, we observed a lower cortisol stress response among children with LG /S alleles compared with children with La/La alleles, and this was particularly evident among children of mothers reporting greater third trimester depressed mood. Our findings suggest that pSRI exposure and a genetic factor associated with modulating 5HT signaling shaped HPA reactivity to a laboratory stress challenge at school age.

Prevalence and risk factors for hypothalamus-pituitary-adrenal axis suppression in infants receiving glucocorticoid eye drops after ocular surgery.

PURPOSE: To examine the prevalence and risk factors for hypothalamus-pituitary-adrenal axis suppression (HPA axis suppression) in infants receiving glucocorticoid (GC) eye drops after ocular surgery. METHODS: This was a clinical observational cohort study. Children under the age of two receiving GC eye drops after cataract or glaucoma surgery between 1 January 2017 and 31 December 2021 were included at one centre. Medical history and results of the adrenocorticotropic hormone (ACTH) stimulation tests were obtained through patient charts. RESULTS: Forty-nine infants were included in the study. Ten out of 22 patients (45.5%) tested during treatment and two out of 27 patients (7.4%) tested after treatment cessation were diagnosed with HPA axis suppression. The duration of HPA axis suppression extended beyond 3 months in 8 out of 12 patients. Logistic regression showed that infants with HPA axis suppression had received a higher GC dose/body weight/day before the first ACTH test (p < 0.001). There was a 79% (95% CI:1.28;2.50) increase in the odds of having HPA axis suppression for a 0.01 mg GC increase/kg/day corresponding to an additional daily eye drop for an infant weighing 5 kg. There was an association between HPA axis suppression and number of days from surgery to test (p = 0.003), age at surgery (p = 0.035) and cumulated GC dose (p = 0.005). Three infants with HPA axis suppression had affected growth and one had Cushing-like features, but there were no cases of Addisonian crisis. CONCLUSION: Infants are at risk of having hypothalamus-pituitary-adrenal axis suppression if they receive a high daily glucocorticoid dose per weight by topical ocular administration. Infants receiving glucocorticoids after ocular surgery should be monitored clinically or by ACTH testing.

Suppression of adult cytogenesis in the rat brain leads to sex-differentiated disruption of the HPA axis activity.

OBJECTIVES: The action of stress hormones, mainly glucocorticoids, starts and coordinates the systemic response to stressful events. The HPA axis activity is predicated on information processing and modulation by upstream centres, such as the hippocampus where adult-born neurons (hABN) have been reported to be an important component in the processing and integration of new information. Still, it remains unclear whether and how hABN regulates HPA axis activity and CORT production, particularly when considering sex differences. MATERIALS AND METHODS: Using both sexes of a transgenic rat model of cytogenesis ablation (GFAP-Tk rat model), we examined the endocrinological and behavioural effects of disrupting the generation of new astrocytes and neurons within the hippocampal dentate gyrus (DG). RESULTS: Our results show that GFAP-Tk male rats present a heightened acute stress response. In contrast, GFAP-Tk female rats have increased corticosterone secretion at nadir, a heightened, yet delayed, response to an acute stress stimulus, accompanied by neuronal hypertrophy in the basal lateral amygdala and increased expression of the glucocorticoid receptors in the ventral DG. CONCLUSIONS: Our results reveal that hABN regulation of the HPA axis response is sex-differentiated.

Glucocorticoid Production in Lymphoid Organs: Acute Effects of Lipopolysaccharide in Neonatal and Adult Mice.

Glucocorticoids (GCs) are critical modulators of the immune system. The hypothalamic-pituitary-adrenal (HPA) axis regulates circulating GC levels and is stimulated by endotoxins. Lymphoid organs also produce GCs; however, it is not known how lymphoid GC levels are regulated in response to endotoxins. We assessed whether an acute challenge of lipopolysaccharide (LPS) increases lymphoid levels of progesterone and GCs, and expression of steroidogenic enzymes and key HPA axis components (eg, corticotropin-releasing hormone [CRH], adrenocorticotropic hormone [ACTH]). We administered LPS (50 µg/kg intraperitoneally) or vehicle control to male and female C57BL/6J neonatal (postnatal day [PND] 5) and adult (PND90) mice and collected blood, bone marrow, thymus, and spleen 4 hours later. We measured progesterone, 11-deoxycorticosterone, corticosterone, and 11-dehydrocorticosterone via liquid chromatography-tandem mass spectrometry. We measured gene expression of key steroidogenic enzymes (Cyp11b1, Hsd11b1, and Hsd11b2) and HPA axis components (Crh, Crhr1, Pomc, and Mc2r) via quantitative polymerase chain reaction. At PND5, LPS induced greater increases in steroid levels in lymphoid organs than in blood. In contrast, at PND90, LPS induced greater increases in steroid levels in blood than in lymphoid organs. Steroidogenic enzyme transcripts were present in all lymphoid organs, and LPS altered steroidogenic enzyme expression predominantly in the spleen. Lastly, we detected transcripts of key HPA axis components in all lymphoid organs, and there was an effect of LPS in the spleen. Taken together, these data suggest that LPS regulates GC production by lymphoid organs, similar to its effects on the adrenal glands, and the effects of LPS might be mediated by local expression of CRH and ACTH.

Impact of Hydrocortisone and of CRH Infusion on the Hypothalamus-Pituitary-Adrenocortical Axis of Septic Male Mice.

PURPOSE: Sepsis is hallmarked by high plasma cortisol/corticosterone (CORT), low adrenocorticotropic hormone (ACTH), and high pro-opiomelanocortin (POMC). While corticotropin-releasing hormone-(CRH) and arginine-vasopressin (AVP)-driven pituitary POMC expression remains active, POMC processing into ACTH becomes impaired. Low ACTH is accompanied by loss of adrenocortical structure, although steroidogenic enzymes remain expressed. We hypothesized that treatment of sepsis with hydrocortisone (HC) aggravates this phenotype whereas CRH infusion safeguards ACTH-driven adrenocortical structure. METHODS: In a fluid-resuscitated, antibiotics-treated mouse model of prolonged sepsis, we compared the effects of HC and CRH infusion with placebo on plasma ACTH, POMC, and CORT; on markers of hypothalamic CRH and AVP signaling and pituitary POMC processing; and on the adrenocortical structure and markers of steroidogenesis. In adrenal explants, we studied the steroidogenic capacity of POMC. RESULTS: During sepsis, HC further suppressed plasma ACTH, but not POMC, predominantly by suppressing sepsis-activated CRH/AVP-signaling pathways. In contrast, in CRH-treated sepsis, plasma ACTH was normalized following restoration of pituitary POMC processing. The sepsis-induced rise in markers of adrenocortical steroidogenesis was unaltered by CRH and suppressed partially by HC, which also increased adrenal markers of inflammation. Ex vivo stimulation of adrenal explants with POMC increased CORT as effectively as an equimolar dose of ACTH. CONCLUSIONS: Treatment of sepsis with HC impaired integrity and function of the hypothalamic-pituitary-adrenal axis at the level of the pituitary and the adrenal cortex while CRH restored pituitary POMC processing without affecting the adrenal cortex. Sepsis-induced high-circulating POMC may be responsible for ongoing adrenocortical steroidogenesis despite low ACTH.

The Type of Fat in the Diet Influences Regulatory Aminopeptidases of the Renin-Angiotensin System and Stress in the Hypothalamic-Pituitary-Adrenal Axis in Adult Wistar Rats.

(1) Background: Prolonged feeding with a high-fat diet (HFD) acts as a stressor by activating the functions of the hypothalamic-pituitary-adrenal gland (HPA) stress axis, accompanied of hypertension by inducing the renin-angiotensin-aldosterone system. Angiotensinases enzymes are regulatory aminopeptidases of angiotensin metabolism, which together with the dipeptidyl peptidase IV (DPP-IV), pyroglutamyl- and tyrosyl-aminopeptidase (pGluAP, TyrAP), participate in cognitive, stress, metabolic and cardiovascular functions. These functions appear to be modulated by the type of fat used in the diet. (2) Methods: To analyze a possible coordinated response of aminopeptidases, their activities were simultaneously determined in the hypothalamus, adenohypophysis and adrenal gland of adult male rats fed diets enriched with monounsaturated (standard diet (S diet) supplemented with 20% virgin olive oil; VOO diet) or saturated fatty acids (diet S supplemented with 20% butter and 0.1% cholesterol; Bch diet). Aminopeptidase activities were measured by fluorimetry using 2-Naphthylamine as substrates. (3) Results: the hypothalamus did not show differences in any of the experimental diets. In the pituitary, the Bch diet stimulated the renin-angiotensin system (RAS) by increasing certain angiotensinase activities (alanyl-, arginyl- and cystinyl-aminopeptidase) with respect to the S and VOO diets. DPP-IV activity was increased with the Bch diet, and TyrAP activity decrease with the VOO diet, having both a crucial role on stress and eating behavior. In the adrenal gland, both HFDs showed an increase in angiotensinase aspartyl-aminopeptidase. The interrelation of angiotensinases activities in the tissues were depending on the type of diet. In addition, correlations were shown between angiotensinases and aminopeptidases that regulate stress and eating behavior. (4) Conclusions: Taken together, these results support that the source of fat in the diet affects several peptidases activities in the HPA axis, which could be related to alterations in RAS, stress and feeding behavior.

HPA axis dysregulation is associated with differential methylation of CpG-sites in related genes.

DNA methylation shifts in Hypothalamic-pituitary-adrenal (HPA) axis related genes is reported in psychiatric disorders including hypersexual disorder. This study, comprising 20 dexamethasone suppression test (DST) non-suppressors and 73 controls, examined the association between the HPA axis dysregulation, shifts in DNA methylation of HPA axis related genes and importantly, gene expression. Individuals with cortisol level ≥ 138 nmol/l, after the low dose (0.5 mg) dexamethasone suppression test (DST) were classified as non-suppressors. Genome-wide methylation pattern, measured in whole blood using the EPIC BeadChip, investigated CpG sites located within 2000 bp of the transcriptional start site of key HPA axis genes, i.e.: CRH, CRHBP, CRHR-1, CRHR-2, FKBP5 and NR3C1. Regression models including DNA methylation M-values and the binary outcome (DST non-suppression status) were performed. Gene transcripts with an abundance of differentially methylated CpG sites were identified with binomial tests. Pearson correlations and robust linear regressions were performed between CpG methylation and gene expression in two independent cohorts. Six of 76 CpG sites were significantly hypermethylated in DST non-suppressors (nominal P < 0.05), associated with genes CRH, CRHR1, CRHR2, FKBP5 and NR3C1. NR3C1 transcript AJ877169 showed statistically significant abundance of probes differentially methylated by DST non-suppression status and correlated with DST cortisol levels. Further, methylation levels of cg07733851 and cg27122725 were positively correlated with gene expression levels of the NR3C1 gene. Methylation levels of cg08636224 (FKBP5) correlated with baseline cortisol and gene expression. Our findings revealed that DNA methylation shifts are involved in the altered mechanism of the HPA axis suggesting that new epigenetic targets should be considered behind psychiatric disorders.

Effect of Constant Illumination on the Function of the Hypothalamic-Pituitary-Adrenal Axis in Nonhuman Primates.

We studied the effect of constant illumination on the effects of administration of arginine vasopressin (AVP), one of the most important regulators of the key adaptive hypothalamic-pituitary-adrenal (HPA) axis under basal conditions and during stress, as well as on the circadian rhythm of activity of HPA axis and the pineal gland in laboratory primates. In young adult female rhesus monkeys exposed to constant illumination for 7 weeks, the rise in the concentration of ACTH and cortisol in response to administration of AVP was markedly reduced in comparison with both the basal period and with the control group of animals. In addition, a destructive effect of constant lighting on circadian rhythm of cortisol secretion was observed in the absence of significant circadian changes in melatonin secretion. The inhibitory effect of constant illumination on the function of the HPA axis under basal conditions and under conditions of its activation can reduce the body's adaptive abilities.

Rationale of a lower dexamethasone dose in prenatal congenital adrenal hyperplasia therapy based on pharmacokinetic modelling.

CONTEXT: Prenatal dexamethasone therapy is used in female foetuses with congenital adrenal hyperplasia to suppress androgen excess and prevent virilisation of the external genitalia. The traditional dexamethasone dose of 20 µg/kg/day has been used since decades without examination in clinical trials and is thus still considered experimental. OBJECTIVE: As the traditional dexamethasone dose potentially causes adverse effects in treated mothers and foetuses, we aimed to provide a rationale of a reduced dexamethasone dose in prenatal congenital adrenal hyperplasia therapy based on a pharmacokinetics-based modelling and simulation framework. METHODS: Based on a published dexamethasone dataset, a nonlinear mixed-effects model was developed describing maternal dexamethasone pharmacokinetics. In stochastic simulations (n = 1000), a typical pregnant population (n = 124) was split into two dosing arms receiving either the traditional 20 µg/kg/day dexamethasone dose or reduced doses between 5 and 10 µg/kg/day. Target maternal dexamethasone concentrations, identified from the literature, served as a threshold to be exceeded by 90% of mothers at a steady state to ensure foetal hypothalamic-pituitary-adrenal axis suppression. RESULTS: A two-compartment dexamethasone pharmacokinetic model was developed and subsequently evaluated to be fit for purpose. The simulations, including a sensitivity analysis regarding the assumed foetal:maternal dexamethasone concentration ratio, resulted in 7.5 µg/kg/day to be the minimum effective dose and thus our suggested dose. CONCLUSIONS: We conclude that the traditional dexamethasone dose is three-fold higher than needed, possibly causing harm in treated foetuses and mothers. The clinical relevance and appropriateness of our recommended dose should be tested in a prospective clinical trial.

Transcriptomic study of the mechanism by which the Kai Yu Zhong Yu recipe improves oocyte quality in a stressed mouse model.

ETHNOPHARMACOLOGICAL RELEVANCE: The Kai Yu Zhong Yu recipe (KYZY) is a classic herbal formula in traditional Chinese medicine (TCM) that has been used to treat infertility associated with psychological stress for more than three hundred years. AIM OF THE STUDY: Psychological stress has major impacts on fertility, with variable outcomes depending on the nature, strength, and duration of the stress. Stress can directly disturb ovulation, oocyte quality, maturation, and embryo development. The aim of this study is to investigate the molecular mechanism by which KYZY improves oocyte developmental potential under psychological stress. MATERIALS AND METHODS: ICR female mice aged 4-5 weeks were randomly divided into five groups: control, stressed in the chronic unpredictable stress model (CUSM), and stressed plus KYZY treatment at 38.2 g/kg (KYZYH), 19.1 g/kg (KYZYM), or 9.6 g/kg (KYZYL). Ovary function was assessed by measuring serum levels of estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and anti-Müllerian hormone (AMH). Oocyte quality was evaluated in terms of reactive oxygen species (ROS) levels, apoptotic DNA fragmentation, and mitochondria distribution. We used RNA sequencing (RNAseq) to identify differentially expressed genes (DEGs) between groups and then further analyzed the DEGs for gene ontology (GO) term enrichment and protein-protein interactions. RESULTS: Mice in the stressed group had reduced serum E2, LH, and FSH as well as increased ROS levels, increased apoptosis, and disturbed mitochondria distribution in oocytes. Treatment with KYZY at all three doses reversed or ameliorated these negative effects of stress. DEG analysis identified 187 common genes between the two comparisons (stressed vs. control and KYZYM vs. stressed), 33 of which were annotated with six gene ontology (GO)'s biological process (BP) terms: cell differentiation, apoptosis, ATP synthesis, protein homo-oligomerization, neuron migration, and negative regulation of peptidase activity. Protein-protein interaction network analysis of DEGs identified key hub genes. Notably, the genes Atp5o and Cyc1 were both involved in the ATP synthesis and among the top three hub genes, suggesting that regulation of oocyte mitochondrial electron transport and ATP synthesis is important in the response to stress and also is a possible mechanism of action for KYZY. CONCLUSIONS: KYZY was effective in ameliorating the adverse effects of stress on oocyte competence, possibly by targeting the mitochondrial respiratory chain and ATP synthase.

Loss of vagal integrity disrupts immune components of the microbiota-gut-brain axis and inhibits the effect of Lactobacillus rhamnosus on behavior and the corticosterone stress response.

The vagus nerve is one of the major signalling components between the gut microbiota and brain. However, the exact relationship between gut-brain signaling along the vagus and the effects of gut microbes on brain function and behaviour is unclear. In particular, the relationship between the vagus nerve and immune signaling, that also appears to play a critical role in microbiota-gut-brain communication, has not been delineated. The aim of the present study was to determine the effect of subdiaphragmatic vagotomy on peripheral and central immune changes associated with the anxiolytic actions of L.rhamnosus. Male mice underwent vagotomy or sham surgery, followed by administration of L.rhamnosus for 14 days. L.rhamnosus administration following sham surgery resulted in reduced anxiety-like behaviour, and an attenuation of the hypothalamic-pituitary-adrenal axis (HPA axis), as indicated by reduced plasma corticosterone after acute restraint stress. These effects were associated with an increase in splenic T regulatory cells and a decrease in activated microglia in the hippocampus. The anxiolytic effects, HPA modulation and increase in T regulatory cells were prevented by vagotomy, whereas vagotomy alone led to a significant increase in activated microglia in the hippocampus that was not altered with L.rhamnosus treatment. Thus, both microbe induced and constitutive vagal signaling influences critical immune components of the microbiota-gut-brain axis. These findings suggest that, rather than acting as a direct neural link to the central nervous system, the role of the vagus nerve in gut-microbe to brain signalling is as an integral component of a bi-directional neuroimmunoendocrine pathway.

A GLP-1 Receptor Agonist Inhibits Aldosterone Release in Healthy Volunteers.

Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) are antidiabetic drugs with effects beyond antihyperglycemic action. The aim of the study was to examine whether a single dose of exenatide could be used as a stimulation test for the pituitary-adrenal axis. We carried out a single-group, open-label pilot clinical trial in an ambulatory setting. Ten healthy volunteers of both sexes with body weight>65 kg and age between 18-50 years were recruited. After fasting for 12 hours the subjects received 10 µg of exenatide solution subcutaneously. Blood samples were taken before the administration of exenatide and up to 150 minutes thereafter. The primary outcome was the maximal level of cortisol after the administration of exenatide. Single administration of exenatide 10 µg resulted in a modest increase in ACTH and cortisol levels, as compared to untreated values, and a decrease in blood glucose levels. Remarkably, a robust suppression of both renin and aldosterone levels occurred. We showed that acute administration of exenatide in a full therapeutic dose modestly stimulates the hypothalamic-pituitary-adrenal axis but inhibits the renin-aldosterone system. Further research is warranted to confirm this finding in the placebo-controlled study.