Displacement of PKA catalytic subunit from AKAP signaling islands drives pathology in Cushing's syndrome

Mutations in the catalytic subunit of protein kinase A (PKAc) drive the stress hormone disorder adrenal Cushing's syndrome. Here we define mechanisms of action for the PKAc-L205R and W196R variants. Both Cushing's mutants are excluded from A kinase anchoring protein (AKAP) signaling islands and consequently diffuse throughout the cell. Kinase-dead experiments show that PKA activity is required for cortisol hypersecretion. However, kinase activation is not sufficient, as only cAMP analog drugs that displace native PKAc from AKAPs enhance cortisol release. Rescue experiments that incorporate mutant PKAc into AKAP signaling islands abolish cortisol overproduction, indicating that kinase anchoring restores normal endocrine function. Phosphoproteomics show that PKAc-L205R and W196R engage different mitogenic signaling pathways. ERK activity is elevated in adrenal-specific PKAc-W196R knock-in mice. Conversely, PKAc-L205R attenuates Hippo signaling, thereby upregulating the YAP/TAZ transcriptional co-activators. Thus, aberrant localization of each Cushing's variant promotes the transmission of a distinct downstream pathogenic signal.

The increase in urinary serotonin and decrease in salivary cortisol concentrations following direct inhalations of concentrated essential oils is not induced by non-specific effects

Objectives. The effectiveness of exogenously triggered serotonin (e.g., dietary supplements, drugs) increase is varied. However, since urinary serotonin concentrations were found to correlate with those in the cerebrospinal fluid, the olfactory system might be an efficient and testable pathway to quickly elevate serotonin levels due to its fast-acting central neurophysiological and peripheral pathways. However, little research has been devoted to investigate this assumption. This paper extends previous findings of parasympathetic activation of a specially designed essential oil inhaler (AromaStick® Balance) by experimentally testing its impact on urine serotonin and saliva cortisol excretion. Method. Two experiments involving healthy individuals were conducted to test the efficacy of essential oil application to the nose by employing different inhalation protocols and control conditions. Results. In the pilot study (n=8), serotonin urine excretion was increased after six inhalations (effect size Cohen’s d=0.7). In the second experiment (n=80), inhalations proved superior to both the natural control condition and the pseudo placebo condition after three and six inhalation cycles (0.6<d<1.8). In addition, there was a large reduction of cortisol saliva levels after three inhalations (d=0.9). Conclusion. Short and deep inhalations of essential oil scents directly delivered to the olfac-tory system appear to result in an enhanced serotonin and a reduced cortisol release in healthy individuals of both sexes.

Nesfatin-1 stimulates the hypothalamus-pituitary-interrenal axis hormones in goldfish

Stress in vertebrates is mediated by the hypothalamus-pituitary-adrenal (in mammals)/interrenal (in fish) (HPA/I) axis, which produces the corticotropin-releasing factor (CRF), adrenocorticotropic hormone (ACTH), and corticosteroids, respectively. Nesfatin-1, a novel anorexigenic peptide encoded in the precursor nucleobindin-2 (NUCB2), is increasingly acknowledged as a peptide that influences the stress axis in mammals. The primary aim of this study was to characterize the putative effects of nesfatin-1 on the fish HPI axis, using goldfish ( Carassius auratus) as an animal model. Our results demonstrated that nucb2/nesfatin-1 transcript abundance was detected in the HPI tissues of goldfish, with most abundant expression in the pituitary. NUCB2/nesfatin-1-like immunoreactivity was found in the goldfish hypothalamus, pituitary, and interrenal cells of the head kidney. GPCR12, a putative receptor for nesfatin-1, was also detected in the pituitary and interrenal cells. NUCB2/nesfatin-1-like immunoreactivity was observed in ACTH-expressing pituitary corticotrophs. Acute netting and restraint stress upregulated nucb2/nesfatin-1 mRNA levels in the forebrain, hypothalamus, and pituitary, as well as crf and crf-r1 expression in the forebrain and hypothalamus. Intraperitoneal and intracerebroventricular administration of nesfatin-1 increased cortisol release and hypothalamic crf mRNA levels, respectively. Finally, we found that nesfatin-1 significantly stimulated ACTH secretion from dispersed pituitary cells in vitro. Collectively, our data provide the first evidence showing that nesfatin-1 is a stress responsive peptide, which modulates the stress axis hormones in fish.

Now or Later? Stress-Induced Increase and Decrease in Choice Impulsivity Are Both Associated with Elevated Affective and Endocrine Responses

Exposure to acute stress elicit physiological and psychological responses that can impact decision-making, often expressed as an increased tendency to act in an impulsive manner following stress. Delay discounting (DD) task has emerged as a reliable measure of impulsive behavior in the form of choice impulsivity (CI). Interestingly, studies that examined the effect of acute stress on DD performance reported mixed results. To address this, we conducted a within-subject examination of the impact of acute stress on CI, focusing on individual differences in response patterns. One hundred and fifty healthy female participants completed the DD task twice, before and after undergoing an acute laboratory stress induction procedure. Saliva samples and self-report mood and affect measures were collected at four time points throughout the session. Fifty-nine matched healthy control participants completed only the DD task twice, with no stress in between. Results indicate that the acute stress procedure elicited the expected effects of increased cortisol release and increased negative mood and affect, at the group level. With respect to DD, stress indeed increased CI at the group level, yet participants differed in the magnitude and direction of this effect. Interestingly, regression analysis revealed quadratic relations between stress-induced changes in CI and cortisol release. Indeed, dividing the sample into three sub-groups based on the impact of stress on CI revealed that, compared to participants that exhibited no substantial change in their CI following stress, participants that exhibited either stress-induced increase or decrease in their CI also exhibited more stress-induced cortisol release, as well as more negative affect. Taken together, these findings suggest that elevated physiological and psychological responses to stress are associated with either increased or decreased choice impulsivity, thus depicting quadratic relations between stress and impulsivity.

Ansiedad social subclínica en adultos jóvenes sanos: cortisol y ansiedad subjetiva en respuesta a estrés agudo

No existe consenso sobre el patrón de liberación de cortisol y su relación con la ansiedad subjetiva en situaciones de estrés en población con ansiedad social. Nuestro objetivo fue determinar la respuesta de cortisol y ansiedad subjetiva en individuos con ansiedad social sometidos a un estresor psicosocial agudo. 26 universitarios (58.6% hombres), edad media = 21.62 ± 0.43, fueron expuestos a la versión estrés o control del Maastricht Acute Stress Test. El cortisol salival y la ansiedad subjetiva fueron medidos antes, durante y post-estrés. Los participantes mostraron un incremento en los niveles de cortisol durante las fases de estrés y post-estrés, con una respuesta significativamente mayor en aquellos con ansiedad social. Los participantes con alta ansiedad social mostraron, a nivel muestral, mayores niveles de ansiedad subjetiva, especialmente post-estrés. Sólo en la fase de estrés, el cortisol y la ansiedad subjetiva correlacionaron significativamente en los participantes socialmente ansiosos. Los hallazgos apoyan una hiperresponsividad de cortisol en población no clínica y joven con alta ansiedad social. Futuras investigaciones deberían estudiar los factores involucrados y efectos de esta respuesta fisiológica en la salud. Asimismo, se resalta la necesidad de controlar la ansiedad social en experimentos que utilicen un estresor psicosocial de laboratorio. There is no consensus about the pattern of cortisol release and its relationship with subjective anxiety in situations of stress in the population with social anxiety. Our aim was to determine the cortisol and subjective anxiety response in individuals with social anxiety subjected to an acute psychosocial stressor. 26 college students (58.6% males), mean age = 21.62 ± 0.43, were exposed to the stress or control adaptation of the Maastricht Acute Stress Test. Salivary cortisol and subjective anxiety were measured before, during, and after stress. Participants showed an increase in cortisol levels during the stress and post-stress phases, with a significantly higher response in those with high social anxiety. Participants with high social anxiety also showed, as a tendency, higher levels of subjective anxiety, especially in the post-stress phase. Only in the stress phase, cortisol and subjective anxiety correlated significantly in socially anxious participants. The findings support a cortisol hyperresponsiveness in a young, non-clinical population with high social anxiety. Future research should focus on the factors involved and the effects of this physiological response on health. Furthermore, the need to control social anxiety in experiments using a laboratory psychosocial stressor is highlighted.

Oxytocin and cortisol release during suckling, hand-milking and machine milking in camels

This research paper addresses the hypothesis that oxytocin (OT) could be released during suckling and during milking with and without the presence of a calf and that this release could be regulated by maternal behaviour. Plasma concentration patterns of OT and cortisol (CORT) were measured in six Tunisian dromedary camels during 2 suckling episodes, 2 manual milking episodes with calves beside the mother and 2 machine milking episodes without calves present. Various patterns of OT release were observed between each camel including specific two peak release patterns. Higher plasma OT concentrations were found during the suckling and hand-milking episodes with simultaneous suckling of calves, than during the machine milking episodes without calves. Exclusive mechanical milking episodes also evoked significant mean OT release, although greatly reduced compared to suckling and hand milking. The low basal levels and classical CORT release patterns suggested non-stressful management practices were used and there were very limited differences in udder stimulation between managements. The OT release induced by exclusive suckling and suckling together with hand-milking gives a reference point for what a good milk ejection stimulation is in camels. The important and specific reduction of OT release during machine milking without the calf present could be a physiological consequence of the maternal behaviour (selectivity for the own young) and to a lesser extent explained by a lower stimulation by machine milking.

The Role of HPA Axis and Allopregnanolone on the Neurobiology of Major Depressive Disorders and PTSD

Under stressful conditions, the hypothalamic-pituitary-adrenal (HPA) axis acts to promote transitory physiological adaptations that are often resolved after the stressful stimulus is no longer present. In addition to corticosteroids (e.g., cortisol), the neurosteroid allopregnanolone (3α,5α-tetrahydroprogesterone, 3α-hydroxy-5α-pregnan-20-one) participates in negative feedback mechanisms that restore homeostasis. Chronic, repeated exposure to stress impairs the responsivity of the HPA axis and dampens allopregnanolone levels, participating in the etiopathology of psychiatric disorders, such as major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). MDD and PTSD patients present abnormalities in the HPA axis regulation, such as altered cortisol levels or failure to suppress cortisol release in the dexamethasone suppression test. Herein, we review the neurophysiological role of allopregnanolone both as a potent and positive GABAergic neuromodulator but also in its capacity of inhibiting the HPA axis. The allopregnanolone function in the mechanisms that recapitulate stress-induced pathophysiology, including MDD and PTSD, and its potential as both a treatment target and as a biomarker for these disorders is discussed.

A Re-Examination of the oCRH Stimulation Test for the Diagnosis of Ectopic ACTH Secretion

Background: Previous studies of the oCRH test for the differential diagnosis of ACTH-dependent Cushing’s syndrome gave imprecise point estimates of specificity because of small numbers (n&lt;20) of patients with ectopic ACTH secretion (EAS). We examined a large EAS population to re-assess the test’s performance and whether benign tumors were associated with a positive response (i.e. Cushing’s disease (CD). Methods: We evaluated 103 EAS patients, including 58 females, with median age of 38 years (range 10 - 83); 99 had surgically-proven tumors and four had biochemical testing consistent with EAS. ACTH and cortisol were measured 5 and 0 minutes before and 15, 30 and 45 minutes after administration of oCRH, 1 ug/kg up to 100 ug, iv. Previous criteria were used to determine EAS responses: mean ACTH increase of &lt;34% at 15 and 30 min or mean cortisol increase of &lt;20% at 30 and 45 min. Mean responses and UFC (expressed as fold increase above upper limit of normal, ULN) were compared with t-tests; a p-value of &lt; 0.05 was considered significant. Results: Tumor types included NET (pulmonary n=67; with 4 spindle type and 5 tumorlets, thymic n=9, pancreas n=7, appendix n=1, prostate n=1), SCLC (N=3), pheochromocytoma/paraganglioma (n=3/1), metastatic without known primary (n=3), teratoma with corticotroph elements (n=1) and occult (n=4). 23 patients had “CD” responses that were significantly higher than those of non-responders: 11 with ACTH (mean+SD: 83.7 + 49.8% vs 1.2 + 18.8%, p=00025), 15 with cortisol (mean+SD: 34.7 + 8.9% vs -1.7 + 14.2%, p&lt; 0.00001). Three patients responded to both ACTH and cortisol. Among the ACTH (only) responders, 6 had cortisol increases of &lt; 10% (range 0-2-8.5%); a similar discordant response was seen among cortisol (only) responders, of whom 7 had ACTH increases of &lt;20% (range -18 - 13.4%). 70% of responders, including 3 with both ACTH and cortisol responses, had pulmonary NET (n=13), spindle cell NET (n=2) or tumorlets (n=4). Other responders had thymic NET (n=3), appendiceal NET n=1, teratoma (n=1) or were occult (n=2). The patient with corticotroph elements in a teratoma had an ACTH response only. UFC fold-increases above ULN were similar in responders and non-responders (20.20 + 26.9 xULN vs 31.4 + 38.4 xULN, p =0.21). Four of 10 patients with UFC cyclicity responded to CRH. Conclusions: Among patients with EAS the rate of false positive responses to CRH was similar to that of initial reports, 11–15%, and was associated with hormonal cyclicity and presence of a thymic carcinoid. The marked discordance of ACTH and cortisol responses may result from reduced sensitivity to ACTH, less biologically active ACTH, or autonomous cortisol release.

The Lack of Light-Dark and Feeding-Fasting Cycles Alters Temporal Events in the Goldfish (Carassius auratus) Stress Axis

Vertebrates possess circadian clocks, driven by transcriptional–translational loops of clock genes, to orchestrate anticipatory physiological adaptations to cyclic environmental changes. This work aims to investigate how the absence of a light-dark cycle and a feeding schedule impacts the oscillators in the hypothalamus-pituitary-interrenal axis of goldfish. Fish were maintained under 12L:12D feeding at ZT 2; 12L:12D feeding at random times; and constant darkness feeding at ZT 2. After 30 days, fish were sampled to measure daily variations in plasma cortisol and clock gene expression in the hypothalamus-pituitary-interrenal (HPI) axis. Clock gene rhythms in the HPI were synchronic in the presence of a light-dark cycle but were lost in its absence, while in randomly fed fish, only the interrenal clock was disrupted. The highest cortisol levels were found in the randomly fed group, suggesting that uncertainty of food availability could be as stressful as the absence of a light-dark cycle. Cortisol daily rhythms seem to depend on central clocks, as a disruption in the adrenal clock did not impede rhythmic cortisol release, although it could sensitize the tissue to stress.