Gut-brain axis in the pathogenesis of sepsis-associated encephalopathy

The gut-brain axis is a bidirectional communication network linking the gut and the brain, overseeing digestive functions, emotional responses, body immunity, brain development, and overall health. Substantial research highlights a connection between disruptions of the gut-brain axis and various psychiatric and neurological conditions, including depression and Alzheimer's disease. Given the impact of the gut-brain axis on behavior, cognition, and brain diseases, some studies have started to pay attention to the role of the axis in sepsis-associated encephalopathy (SAE), where cognitive impairment is the primary manifestation. SAE emerges as the primary and earliest form of organ dysfunction following sepsis, potentially leading to acute cognitive impairment and long-term cognitive decline in patients. Notably, the neuronal damage in SAE does not stem directly from the central nervous system (CNS) infection but rather from an infection occurring outside the brain. The gut-brain axis is posited as a pivotal factor in this process. This review will delve into the gut-brain axis, exploring four crucial pathways through which inflammatory signals are transmitted and elevate the incidence of SAE. These pathways encompass the vagus nerve pathway, the neuroendocrine pathway involving the hypothalamic-pituitary-adrenal (HPA) axis and serotonin (5-HT) regulation, the neuroimmune pathway, and the microbial regulation. These pathways can operate independently or collaboratively on the CNS to modulate brain activity. Understanding how the gut affects and regulates the CNS could offer the potential to identify novel targets for preventing and treating this condition, ultimately enhancing the prognosis for individuals with SAE.

The mind-skin connection: A narrative review exploring the link between inflammatory skin diseases and psychological stress

Inflammatory skin diseases are known to negatively impact patient psychology, with individuals experiencing higher rates of stress and subsequent diminished quality of life, as well as mental health issues including anxiety and depression. Moreover, increased psychological stress has been found to exacerbate existing inflammatory skin diseases. The association between inflammatory skin diseases and psychological stress is a timely topic, and a framework to better understand the relationship between the two that integrates available literature is needed. In this narrative review article, we discuss potential neurobiological mechanisms behind psychological stress due to inflammatory skin diseases, focusing mainly on proinflammatory cytokines in the circulating system (the brain-gut-skin communications) and the default mode network in the brain. We also discuss potential descending pathways from the brain that lead to aggravation of inflammatory skin diseases due to psychological stress, including the central and peripheral hypothalamic-pituitary-adrenal axes, peripheral nerves and the skin barrier function.

Brain-Thymus Connections in Chagas Disease

BACKGROUND

The brain and the immune systems represent the two primary adaptive systems within the body. Both are involved in a dynamic process of communication, vital for the preservation of mammalian homeostasis. This interplay involves two major pathways: the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system.

SUMMARY

The establishment of infection can affect immunoneuroendocrine interactions, with functional consequences for immune organs, particularly the thymus. Interestingly, the physiology of this primary organ is not only under the control of the central nervous system (CNS) but also exhibits autocrine/paracrine regulatory circuitries mediated by hormones and neuropeptides that can be altered in situations of infectious stress or chronic inflammation. In particular, Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), impacts upon immunoneuroendocrine circuits disrupting thymus physiology. Here, we discuss the most relevant findings reported in relation to brain-thymic connections during T. cruzi infection, as well as their possible implications for the immunopathology of human Chagas disease.

KEY MESSAGES

During T. cruzi infection, the CNS influences thymus physiology through an intricate network involving hormones, neuropeptides, and pro-inflammatory cytokines. Despite some uncertainties in the mechanisms and the fact that the link between these abnormalities and chronic Chagasic cardiomyopathy is still unknown, it is evident that the precise control exerted by the brain over the thymus is markedly disrupted throughout the course of T. cruzi infection.

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.

AVP-eGFP was significantly upregulated by hypovolemia in the parvocellular division of the paraventricular nucleus in the transgenic rats

Arginine vasopressin (AVP) is produced in the paraventricular (PVN) and supraoptic nuclei (SON). Peripheral AVP, which is secreted from the posterior pituitary, is produced in the magnocellular division of the PVN (mPVN) and SON. In addition, AVP is produced in the parvocellular division of the PVN (pPVN), where corticotrophin-releasing factor (CRF) is synthesized. These peptides synergistically modulate the hypothalamic-pituitary-adrenal (HPA) axis. Previous studies have revealed that the HPA axis was activated by hypovolemia. However, the detailed dynamics of AVP in the pPVN under hypovolemic state has not been elucidated. Here, we evaluated the effects of hypovolemia and hyperosmolality on the hypothalamus, using AVP-enhanced green fluorescent protein (eGFP) transgenic rats. Polyethylene glycol (PEG) or 3% hypertonic saline (HTN) was intraperitoneally administered to develop hypovolemia or hyperosmolality. AVP-eGFP intensity was robustly upregulated at 3 and 6 h after intraperitoneal administration of PEG or HTN in the mPVN. While in the pPVN, eGFP intensity was significantly increased at 6 h after intraperitoneal administration of PEG with significant induction of Fos-immunoreactive (-ir) neurons. Consistently, eGFP mRNA, AVP hnRNA, and CRF mRNA in the pPVN and plasma AVP and corticosterone were significantly increased at 6 h after intraperitoneal administration of PEG. The results suggest that AVP and CRF syntheses in the pPVN were activated by hypovolemia, resulting in the activation of the HPA axis.

Hypothalamic-pituitary-thyroid axis function in female adolescent nonsuicidal self-injury and its association with comorbid borderline personality disorder and depression

OBJECTIVES

Behavioral disturbances in adolescence are potentially linked to aberrant functioning of the thyroid gland. Accordingly, alterations of the hypothalamic-pituitary-thyroid (HPT) axis might impact psychopathological development. Yet corresponding research in adolescents with nonsuicidal self-injury (NSSI) and comorbid mental disorders is scarce.

METHODS

The present study examined HPT axis functioning in adolescents with NSSI compared to healthy controls (HC) using blood-based assays of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and the ratio of these hormones (fT3/fT4 ratio). Cortisol was additionally examined to contrast HPT axis functioning with a well-established biomarker of stress responsivity. Moreover, associations between clinical characteristics, HPT axis and HPA axis functioning were investigated. Female adolescents meeting NSSI criteria according to DSM-5 criteria (n = 117) were compared to adolescent HC (n = 41). Standardized serum-based endocrinological assays and interview- and questionnaire-based psychiatric assessments were used. Smoking status was included as covariate for all analyses.

RESULTS

NSSI patients displayed altered HPT axis functioning as fT3/fT4 ratio values were blunted in comparison to HC. Negative correlations were further present between fT3, fT3/fT4 ratio and severity of BPD symptoms, depression scores and symptomatic distress. TSH correlated negatively with severity of BPD symptoms and symptomatic distress exclusively. Cortisol values differed neither significantly between experimental groups nor correlated significantly with clinical characteristics.

CONCLUSIONS

Longitudinal examinations, assessing links between psychopathology and endocrinological alterations, are warranted to address potential clinical implications of thyroid markers in child and adolescent psychiatry.

Clinical advances in the pharmacotherapy of congenital adrenal hyperplasia

BACKGROUND

Patients with 21-hydroxylase deficiency congenital adrenal hyperplasia (21OHD-CAH) have poor health outcomes with increased mortality, short stature, impaired fertility, and increased cardiovascular risk factors such as obesity. To address this, there are therapies in development that target the clinical goal of treatment, which is to control excess androgens with an adrenal replacement dose of glucocorticoid.

METHODS

Narrative review of publications on recent clinical developments in the pharmacotherapy of congenital adrenal hyperplasia.

SUMMARY

Therapies in clinical development target different levels of the hypothalamo-pituitary-adrenal axis. Two corticotrophin-releasing factor type 1 (CRF1) receptor antagonists, Crinecerfont and Tildacerfont, have been trialled in poorly controlled 21OHD-CAH patients, and both reduced ACTH and androgen biomarkers while patients were on stable glucocorticoid replacement. Improvements in glucocorticoid replacement include replacing the circadian rhythm of cortisol that has been trialled with continuous s.c. infusion of hydrocortisone and Chronocort, a delayed-release hydrocortisone formulation. Chronocort optimally controlled 21OHD-CAH in 80% of patients on an adrenal replacement dose of hydrocortisone, which was associated with patient-reported benefits including restoration of menses and pregnancies. Adrenal-targeted therapies include the steroidogenesis-blocking drug Abiraterone acetate, which reduced adrenal androgen biomarkers in poorly controlled patients.

CONCLUSIONS

CRF1 receptor antagonists hold promise to avoid excess glucocorticoid replacement in patients not controlled on standard or circadian glucocorticoid replacement such as Chronocort. Gene and cell therapies are the only therapeutic approaches that could potentially correct both cortisol deficiency and androgen excess.

Diagnostic value of standard deviation score of log-transformed serum dehydroepiandrosterone sulfate in patients with hypothalamic-pituitary-adrenal axis insufficiency

Serum dehydroepiandrosterone sulfate (DHEA-S) levels reflect the state of adrenocorticotropic hormone (ACTH) secretion. However, it is difficult to use serum DHEA-S to diagnose hypothalamic-pituitary-adrenal (HPA) axis insufficiency due to its non-normal and highly skewed distribution. In this study, we focused on HPA insufficiency caused by hypothalamic and/or pituitary dysfunction and evaluated the usefulness of the standard deviation score of log-transformed DHEA-S (ln DHEA-S SD score), which was calculated from the established age- and sex-specific reference values. We retrospectively reviewed the medical records of 94 patients suspected of having HPA insufficiency, in whom serum DHEA-S measurement and the rapid ACTH stimulation test were performed, and included 65 patients who met our criteria in this study. The ln DHEA-S SD scores were distributed more normally than measured DHEA-S levels and were significantly higher in patients with a peak cortisol level ≥18 μg/dL than in those below this value, suggesting that this score is a legitimate and strong indicator of adrenocortical function. The optimal cut-off value for impaired HPA function was -0.853, with a sensitivity of 70.3% and a specificity of 100%. Among the 37 patients whose peak cortisol levels were below 18 μg/dL, 11 patients with ln DHEA-S scores ≥-0.853 exhibited significantly higher basal ACTH and basal and peak cortisol levels than the 26 patients with scores <-0.853. Thus, this score plays a supportive role in evaluating HPA axis function, particularly in patients with borderline cortisol responses to ACTH.

Gut microbiota depletion from early adolescence alters anxiety and depression-related behaviours in male mice with Alzheimer-like disease

The gut-microbiota-brain axis plays an important role in stress-related disorders, and dysfunction of this complex bidirectional system is associated with Alzheimer's disease. This study aimed to assess the idea that whether gut microbiota depletion from early adolescence can alter anxiety- and depression-related behaviours in adult mice with or without Alzheimer-like disease. Male C57BL/6 mice were treated with an antibiotic cocktail from weaning to adulthood. Adult mice received an intracerebroventricular injection of amyloid-beta (Aβ)1-42, and were subjected to anxiety and depression tests. We measured, brain malondialdehyde and glutathione following anxiety tests, and assessed brain oxytocin and the hypothalamic-pituitary-adrenal (HPA) axis function by measuring adrenocorticotrophic hormone (ACTH) and corticosterone following depression tests. Healthy antibiotic-treated mice displayed significant decreases in anxiety-like behaviours, whereas they did not show any alterations in depression-like behaviours and HPA axis function. Antibiotic treatment from early adolescence prevented the development of anxiety- and depression-related behaviours, oxidative stress and HPA axis dysregulation in Alzheimer-induced mice. Antibiotic treatment increased oxytocin in the brain of healthy but not Alzheimer-induced mice. Taken together, these findings suggest that gut microbiota depletion following antibiotic treatment from early adolescence might profoundly affect anxiety- and depression-related behaviours, and HPA axis function in adult mice with Alzheimer-like disease.

Diurnal pattern of salivary cortisol and progression of aortic stiffness: Longitudinal study

BACKGROUND

The positive direct relation between stress and the development of cardiovascular disease has increasingly been recognized. However, the link between hypothalamic-pituitary-adrenal (HPA) dysregulation and subclinical cardiovascular disease has not been studied longitudinally. We investigated the relation of diurnal salivary cortisol, as a biological marker of stress levels, with progression of aortic stiffness over five years.

METHODS

A total of 3281 people (mean age 65.5) in the Whitehall II prospective study provided six saliva samples on a single weekday. We assessed the diurnal salivary cortisol using the daytime slope and bedtime level. Aortic stiffness was measured by carotid-femoral pulse wave velocity (PWV) at baseline (2007-2009) and five years later (2012-2013). Linear mixed models were used to estimate the association of diurnal salivary cortisol with baseline PWV and five-year longitudinal changes.

RESULTS

Diurnal salivary cortisol were not associated with PWV at baseline. Among women but not men, a 1-SD shallower salivary cortisol slope at baseline was associated with a five-year increase in PWV (β = 0.199; 95% CI = 0.040, 0.358 m/s) and higher bedtime cortisol level (β = 0.208, 95% CI = 0.062, 0.354 m/s).

CONCLUSIONS

Dysregulation of the HPA axis measured using salivary cortisol (shallower slope, higher bedtime level) predicted the rate of progression of aortic stiffness among women.

Soporific effect of modified Suanzaoren Decoction on mice models of insomnia by regulating Orexin-A and HPA axis homeostasis

AIM

Modified Suanzaoren Decoction (MSZRD) is obtained by improving Suanzaoren Decoction (SZRT), a traditional Chinese herbal prescription that has been used to treat insomnia for more than thousands of years. Our previous study showed that MSZRD can improve the gastrointestinal discomfort related insomnia by regulating Orexin-A. This study is the first study to evaluate the effects and possible mechanisms of MSZRD in mice with insomnia caused by p-chlorophenylalanine (PCPA) combined with multifactor random stimulation.

METHODS

After 14 days of multifactor stimulation to ICR mice, a PCPA suspension (30 mg/mL) was injected intraperitoneally for two consecutive days to establish an insomnia model. Three different doses of MSZRD (3.6, 7.2, and 14.4 g/kg/day) were given to ICR mice for 24 days. The food intake and back temperature were measured, and behavioral tests and pentobarbital sodium-induced sleep tests were conducted. The levels of Orexin-A, corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and adrenocortical hormones (CORT) in the serum and 5-hydroxytryptamine (5-HT), dopamine (DA), and norepinephrine (NE) in hypothalamus were measured using enzyme-linked immunosorbent assay (ELISA) kits. The levels of γ-aminobutyric acid (GABA) and glutamic acid (Glu) were measured by high-performance liquid chromatography (HPLC). The expression of 5HT1A receptor (5-HTRIA) and orexin receptor 2 antibody (OX2R) was measured by Western blot (WB) and immunohistochemical staining (ICH). Hematoxylin and eosin (H&E) staining and Nissl staining were used to assess the histological changes in hypothalamus tissue.

RESULTS

Of note, MSZRD can shorten the sleep latency of insomnia mice (P < 0.05, 0.01), prolonged the sleep duration of mice (P < 0.05, 0.01), and improve the circadian rhythm disorder relative to placebo-treated animals. Furthermore, MSZRD effectively increased the content of 5-HT and 5-HTR1A protein in the hypothalamus of insomnia mice (P < 0.05, 0.01), while downregulated the content of DA and NE (P < 0.05, 0.01). Importantly, serum GABA concentration was increased by treatment with MSZRD (P < 0.05), as reflected by a decreased Glu/GABA ratio (P < 0.05). Moreover, MSZRD decreased the levels of CORT, ACTH, and CRH related hormones in HPA axis (P < 0.05, 0.01). At the same time, MSZRD significantly downregulated the serum Orexin-A content in insomnia mice (P < 0.05), as well as hypothalamic OX2R expression (P < 0.05). In addition, MSZRD also improved the histopathological changes in hypothalamus in insomnia mice.

CONCLUSION

MSZRD has sleep-improvement effect in mice model of insomnia. The mechanism may be that regulating the expression of Orexin-A affects the homeostasis of HPA axis and the release of related neurotransmitters in mice with insomnia.

Early-Life Stress Reprograms Stress-Coping Abilities in Male and Female Juvenile Rats

Prenatal stress (PS) is a major risk factor for the development of emotional disorders in adulthood that may be mediated by an altered hypothalamic-pituitary-adrenal axis response to stress. Although the early onset of stress-related disorders is recognized as a major public health problem, to date, there are relatively few studies that have examined the incidence of early-life stressors in younger individuals. In this study, we assessed PS impact on the stress-coping response of juvenile offspring in behavioral tests and in the induced molecular changes in the hippocampus. Furthermore, we assessed if pregnancy stress could be driving changes in patterns of maternal behavior during early lactation. We found that PS modified stress-coping abilities of both sex offspring. In the hippocampus, PS increased the expression of bdnf-IV and crfr1 and induced sex difference changes on glucocorticoids and BDNF mRNA receptor levels. PS changed the hippocampal epigenetic landscape mainly in male offspring. Stress during pregnancy enhanced pup-directed behavior of stressed dams. Our study indicates that exposure to PS, in addition to enhanced maternal behavior, induces dynamic neurobehavioral variations at juvenile ages of the offspring that should be considered adaptive or maladaptive, depending on the characteristics of the confronting environment. Our present results highlight the importance to further explore risk factors that appear early in life that will be important to allow timely prevention strategies to later vulnerability to stress-related disorders.

Jie-Yu-He-Huan Capsule Ameliorates Anxiety-Like Behaviours in Rats Exposed to Chronic Restraint Stress via the cAMP/PKA/CREB/BDNF Signalling Pathway

Chronic stress is a critical factor in the aetiology of anxiety disorders; however, in the clinic, enduring and preventive measures are not available, and therapeutic drugs are associated with inevitable side effects. Our study established an anxiety rat model using chronic restraint stress (CRS) and assessed these animals using the open-field test, elevated plus-maze test, and light-dark box test. Jie-Yu-He-Huan capsule (JYHH), a Chinese medicine formula, was used as a preventative drug. The HPA axis-mediated release of corticotropin-releasing hormone, adrenocorticotropic hormone, and corticosterone from the hypothalamus was tested. In the hippocampus and prefrontal cortex, concentrations of 5-HT and its metabolite 5-hydroxyindoleacetic acid, as well as monoamine oxidase A, glucocorticoid receptor, and 5-HT1A receptor expression levels, were measured. Furthermore, we examined protein and mRNA expression of cAMP-PKA-CREB-BDNF pathway components. The results showed that JYHH had a significant preventative effect on the anxiety-like behaviour induced by CRS and prevented abnormal changes in the HPA axis and 5-HT system. Furthermore, CRS inhibited the cAMP-PKA-CREB-BDNF pathway, which returned to normal levels following JYHH treatment. This might be the underlying molecular mechanism of the antianxiety effect of JYHH, which could provide a new clinical target for preventative anxiolytic drugs for chronic stress.

The Cortisol and ACTH Response to Dex/CRH Testing in Women With and Without Perimenopausal Depression

CONTEXT

Abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis are frequent accompaniments of depression, and studies have documented the role of stress and stressful life events in the ontogeny of perimenopausal depressions (PMD). Because HPA axis function in women is further modulated both by aging and ovarian steroids, it is possible that a dysregulated HPA axis contributes to the increased risk of PMD.

OBJECTIVE

We examined HPA axis function in perimenopausal women with and without depression using the combined dexamethasone-corticotropin-releasing hormone (Dex/CRH) test.

METHODS

Dex/CRH tests were performed on 20 women with PMD and 20 women who were also perimenopausal but without current or past depression (control women). Main outcome measures were plasma levels of cortisol and adrenocorticotropin (ACTH) and 24-hour urinary free cortisol (UFC). Five women took chronic stable medications, otherwise all women were medically healthy, and both groups were comparable with respect to reproductive stage and age. Standardized symptom rating scales were administered to each woman prior to Dex/CRH testing.

RESULTS

No group differences were present in either baseline or stimulated ACTH and cortisol secretion. Baseline plasma measures of estradiol, progesterone, and 24-hour UFC levels similarly did not differ in PMD and control women.

CONCLUSION

Despite reports of increased stress responsiveness in PMD, we observed no abnormalities of HPA axis activity associated with PMD compared with women without depression. These findings suggest that PMD is not uniformly associated with HPA dysregulation and could reflect underlying pathophysiologic processes that are distinct from women with nonreproductive-related depressions.

The Role of Thyroid in Renovascular Function: Independent Association of Serum TSH With Renal Plasma Flow

CONTEXT

There are well-established interactions between the thyroid and the kidney. Thyroid hypofunction is associated with reduced renal plasma flow (RPF), and hypothyroidism is highly prevalent in chronic kidney disease; however, less is known about the thyroid-kidney axis in the euthyroid state.

OBJECTIVE

This work aimed to study the association of thyroid function with renovascular parameters in a well-phenotyped cohort of euthyroid normotensive and hypertensive individuals.

METHODS

This cross-sectional, multicenter study of the HyperPATH Consortium took place in 5 US and European academic institutions. A total of 789 individuals, aged 18 to 65 years, with serum thyrotropin (TSH) 0.4 to 5.5 mIU/L, participated; individuals with uncontrolled or secondary hypertension or on medication affecting the hypothalamus-pituitary-thyroid axis were excluded. Hemodynamic parameters including RPF, thyroid function testing, and the Thr92Ala deiodinase 2 (D2) polymorphism were assessed in the setting of a liberal and restricted salt diet. We searched for associations between thyroid function and renovascular parameters and accounted for confounding factors, such as older age, hypertension, and diabetes.

RESULTS

Serum TSH was inversely associated with RPF assessed in the setting both of liberal and restricted salt diets. This association remained significant and independent when accounting for confounding factors, whereas free thyroxine index (fTI) and the Thr92Ala polymorphism, associated with lower D2 catalytic activity and disrupted thyroid hormone tissue availability, were not independently associated with RPF. Serum TSH remained an independent predictor of RPF on a liberal salt diet when the analysis was restricted to healthy young individuals.

CONCLUSION

Serum TSH levels, but not fTI nor the Thr92Ala D2 polymorphism, were independently inversely associated with RPF in individuals of the HyperPATH Consortium. These findings suggest a direct interconnection between TSH and renovascular dynamics even with TSH within reference range, warranting further investigation.

Two Distinctive POMC Promoters Modify Gene Expression in Cushing Disease

CONTEXT

Mechanisms underlying pituitary corticotroph adenoma adrenocorticotropin (ACTH) production are poorly understood, yet circulating ACTH levels closely correlate with adenoma phenotype and clinical outcomes.

OBJECTIVE

We characterized the 5' ends of proopiomelanocortin (POMC) gene transcripts, which encode the precursor polypeptide for ACTH, in order to investigate additional regulatory mechanisms of POMC gene transcription and ACTH production.

METHODS

We examined 11 normal human pituitary tissues, 32 ACTH-secreting tumors, as well as 6 silent corticotroph adenomas (SCAs) that immunostain for but do not secrete ACTH.

RESULTS

We identified a novel regulatory region located near the intron 2/exon 3 junction in the human POMC gene, which functions as a second promoter and an enhancer. In vitro experiments demonstrated that CREB binds the second promoter and regulates its transcriptional activity. The second promoter is highly methylated in SCAs, partially demethylated in normal pituitary tissue, and highly demethylated in pituitary and ectopic ACTH-secreting tumors. In contrast, the first promoter is demethylated in all POMC-expressing cells and is highly demethylated only in pituitary ACTH-secreting tumors harboring the ubiquitin-specific protease 8 (USP8) mutation. Demethylation patterns of the second promoter correlate with clinical phenotypes of Cushing disease.

CONCLUSION

We identified a second POMC promoter regulated by methylation status in ACTH-secreting pituitary tumors. Our findings open new avenues for elucidating subcellular regulation of the hypothalamic-pituitary-adrenal axis and suggest the second POMC promoter may be a target for therapeutic intervention to suppress excess ACTH production.

Hypothalamic-Pituitary-Adrenal axis dysfunction by early life stress

Evidence indicates that early life stress (ELS) may act as a risk factor for the development and maintenance of adulthood severe mental health disorders due to persistent dysregulation within the hypothalamic-pituitary-adrenal (HPA) axis. It is now broadly accepted that psychological stress may change the internal homeostatic state of an individual. The dysregulation seems to be a byproduct of changes noted in the HPA axis hormone's ability to bind to the glucocorticoid and mineralocorticoid receptors, crucial in maintaining homeostasis. Whenever there is an acute interruption of this balance, illness may result. The social and physical environments have an enormous impact on our physiology and behavior, and they influence the process of adaptation or 'allostasis'. The HPA axis response to stress can be thought of as a mirror of the organism's response to stress: acute responses are generally adaptive, but excessive or prolonged responses can lead to deleterious effects. Evidence indicates that early-life stress can induce persistent changes in the ability of the HPA axis to respond to stress in adulthood This review aims to examine and summarise the existing literature exploring the relationship between ELS with regards specifically to HPA axis functioning. The maintenance of the internal homeostatic state of an individual is proposed to be based on the ability of circulating glucocorticoids to exert negative feedback on the secretion of HPA hormones through binding to mineralocorticoid (MR) and glucocorticoid (GR) receptors limiting the vulnerability to diseases related to psychological stress in genetically predisposed individuals.

Epigenetics: A missing link between early life stress and depression

Research has suggested a relationship between early life stress, and depression in particular longer episodes of depression with treatment resistant outcomes. However, the underlying mechanisms for this association remain poorly understood. Molecular studies indicate that, in general, the hereditary character of psychiatric disorders are polygenic, multifactorial and highly complex, with innumerable low-effect genetic variants interacting with each other. In addition, the importance of the environment and its interaction with genes has pointed to a fundamental role of epigenetic mechanisms in psychiatric disorders, such as methylation of deoxyribonucleic acid (DNA), alterations, histone actions and regulation of gene expression by non-coding ribonucleic acids (RNAs). This article provides an overview of the interplay of epigenetics, the HPA axis, early life stress and the development of depression. Advances in our knowledge of epigenetics in the context of early life stress and depression provide a new understanding of the genetic influence on psychopathology and could lead to the identification of new targets for clinical intervention.

Altered endocannabinoid-dynamics in craniopharyngioma patients and their association with HPA-axis disturbances

OBJECTIVE

Patients with craniopharyngioma (CP) frequently suffer from morbid obesity. Endocannabinoids (ECs) are involved in weight gain and rewarding behavior but have not been investigated in this context.

DESIGN

Cross-sectional single-center study.

METHODS

Eighteen patients with CP and 16 age- and sex-matched controls were included. Differences in endocannabinoids (2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA)) and endocannabinoid-like molecules (oleoyl ethanolamide (OEA), palmitoylethanolamide (PEA), and arachidonic acid (AA) were measured at baseline and following endurance exercise. We further explored ECs-dynamics in relation to markers of HPA-axis activity (ACTH, cortisol, copeptin) and hypothalamic damage.

RESULTS

Under resting conditions, independent of differences in BMI, 2-AG levels were more than twice as high in CP patients compared to controls. In contrast, 2-AG and OEA level increased in response to exercise in controls but not in CP patients, while AEA levels decreased in controls. As expected, exercise increased ACTH and copeptin levels in controls only. In a mixed model analysis across time and group, HPA measures did not provide additional information for explaining differences in 2-AG levels. However, AEA levels were negatively influenced by ACTH and copeptin levels, while OEA levels were negatively predicted by copeptin levels only. There were no significant differences in endocannabinoids depending on hypothalamic involvement.

CONCLUSION

Patients with CP show signs of a dysregulated endocannabinoid system under resting conditions as well as following exercise in comparison to healthy controls. Increased 2-AG levels under resting conditions and the missing response to physical activity could contribute to the metabolic phenotype of CP patients.

Thyroid axis activity and dopamine function in depression

BACKGROUND

Several lines of evidence suggest alterations in both hypothalamic-pituitary-thyroid (HPT) axis and dopamine (DA) function in depressed patients. However, the functional relationships between HPT and DA systems have not been well defined.

METHODS

We examined thyrotropin (TSH) response to 0800 h and 2300 h protirelin (TRH) challenges, and adrenocorticotropic hormone (ACTH), cortisol and growth hormone (GH) responses to apomorphine (APO, a DA receptor agonist), in 58 drug-free DSM-IV major depressed inpatients without a suicidal behavior, and 22 healthy hospitalized controls.

RESULTS

Compared with controls, patients showed 1) lower basal serum 2300 h-TSH, 2300 h-∆TSH, and ∆∆TSH (difference between 2300 h-∆TSH and 0800 h-∆TSH) levels, and 2) lower cortisol response to APO (∆COR). A negative relationship between ∆∆TSH values and hormonal responses to APO was observed in the depressed group, but not in the control group. When patients were classified on the basis of their ∆∆TSH status, patients with reduced ∆∆TSH values (< 2.5 mU/L) showed hormonal APO responses comparable to those of controls. Patients with normal ∆∆TSH values exhibited lower ∆ACTH, ∆COR, and ∆GH values than patients with reduced ∆∆TSH values and controls.

CONCLUSION

Taken together, these results suggest that hypothalamic DA function is unaltered in depressed patients with HPT dysregulation (i.e., increased hypothalamic TRH drive leading to altered TRH receptor chronesthesy on pituitary thyrotrophs). Conversely, hypothalamic DA-receptor function is decreased in patients with normal HPT axis activity. These findings are discussed in the context of the role of TRH as a homeostatic neuromodulator in depression.

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.

MANAGEMENT OF ENDOCRINE DISEASE: Diagnosis and management of primary amenorrhea and female delayed puberty

Puberty is the period of transition from childhood to adulthood characterized by the attainment of adult height and body composition, accrual of bone strength and the acquisition of secondary sexual characteristics, psychosocial maturation and reproductive capacity. In girls, menarche is a late marker of puberty. Primary amenorrhea is defined as the absence of menarche in ≥ 15-year-old females with developed secondary sexual characteristics and normal growth or in ≥13-year-old females without signs of pubertal development. Furthermore, evaluation for primary amenorrhea should be considered in the absence of menarche 3 years after thelarche (start of breast development) or 5 years after thelarche, if that occurred before the age of 10 years. A variety of disorders in the hypothalamus-pituitary-ovarian axis can lead to primary amenorrhea with delayed, arrested or normal pubertal development. Etiologies can be categorized as hypothalamic or pituitary disorders causing hypogonadotropic hypogonadism, gonadal disorders causing hypergonadotropic hypogonadism, disorders of other endocrine glands, and congenital utero-vaginal anomalies. This article gives a comprehensive review of the etiologies, diagnostics and management of primary amenorrhea from the perspective of pediatric endocrinologists and gynecologists. The goals of treatment vary depending on both the etiology and the patient; with timely etiological diagnostics fertility may be attained even in those situations where no curable treatment exists.

Positive Correlation between nNOS and Stress-Activated Bowel Motility Is Confirmed by In Vivo HiBiT System

Neuronal nitric oxide synthase (nNOS) has various roles as a neurotransmitter. However, studies to date have produced insufficient data to fully support the correlation between nNOS and bowel motility. This study aimed to investigate the correlation between nNOS expression and gastrointestinal (GI) tract motility using a stress-induced neonatal maternal separation (NMS) mouse model. In this study, we generated a genetically modified mouse with the HiBiT sequence knock-in into the nNOS gene using CRISPR/Cas9 for analyzing accurate nNOS expression. nNOS expression was measured in the stomach, small intestine, large intestine, adrenal gland, and hypothalamus tissues after establishing the NMS model. The NMS model exhibited a significant increase in nNOS expression in large intestine, adrenal gland, and hypothalamus. Moreover, a significant positive correlation was observed between whole gastrointestinal transit time and the expression level of nNOS. We reasoned that NMS induced chronic stress and consequent nNOS activation in the hypothalamic-pituitary-adrenal (HPA) axis, and led to an excessive increase in intestinal motility in the lower GI tract. These results demonstrated that HiBiT is a sensitive and valuable tool for analyzing in vivo gene activation, and nNOS could be a biomarker of the HPA axis-linked lower intestinal tract dysfunction.

The hypothalamus-pituitary-thyroid (HPT)-axis and its role in physiology and pathophysiology of other hypothalamus-pituitary functions

The hypothalamus-pituitary-thyroid axis is one of several hormone regulatory systems from the hypothalamus to the pituitary and ultimately to the peripheral target organs. The hypothalamus and the pituitary gland are in close anatomical proximity at the base of the brain and extended through the pituitary stalk to the sella turcica. The pituitary stalk allows passage of stimulatory and inhibitory hormones and other signal molecules. The target organs are placed in the periphery and function through stimulation/inhibition by the circulating pituitary hormones. The several hypothalamus-pituitary-target organ axis systems interact in very sophisticated and complicated ways and for many of them the interactive and integrated mechanisms are still not quite clear. The diagnosis of central hypothyroidism is complicated by itself but challenged further by concomitant affection of other hypothalamus-pituitary-hormone axes, the dysfunction of which influences the diagnosis of central hypothyroidism. Treatment of both the central hypothyroidism and the other hypothalamus-pituitary axes also influence the function of the others by complex mechanisms involving both central and peripheral mechanisms. Clinicians managing patients with neuroendocrine disorders should become aware of the strong integrative influence from each hypothalamus-pituitary-hormone axis on the physiology and pathophysiology of central hypothyroidism. As an aid in this direction the present review summarizes and highlights the importance of the hypothalamus-pituitary-thyroid axis, pitfalls in diagnosing central hypothyroidism, diagnosing/testing central hypothyroidism in relation to panhypopituitarism, pointing at interactions of the thyroid function with other pituitary hormones, as well as local hypothalamic neurotransmitters and gut-brain hormones. Furthermore, the treatment effect of each axis on the regulation of the others is described. Finally, these complicating aspects require stringent diagnostic testing, particularly in clinical settings with lower or at least altered à priori likelihood of hypopituitarism than in former obvious clinical patient presentations.

MANAGEMENT OF ENDOCRINE DISEASE: Glucocorticoid-induced adrenal insufficiency: replace while we wait for evidence?

Glucocorticoids are, besides non-steroidal anti-inflammatory drugs, the most widely used anti-inflammatory medications. Prevalence studies indicate substantial use of both systemic and locally acting agents. A recognised adverse effect of glucocorticoid treatment is adrenal insufficiency, which is highly prevalent based on biochemical testing, but its clinical implications are poorly understood. Current evidence, including randomised trials and observational studies, indicates substantial variation among patients in both risk and course of glucocorticoid-induced adrenal insufficiency, but both are currently unpredictable. Oral and intra-articular formulations, as well as long-term and high-dose treatments, carry the highest risk of glucocorticoid-induced adrenal insufficiency defined by biochemical tests. However, no route of administration, treatment duration, or dose can be considered without risk. More research is needed to estimate the risk and temporal pattern of glucocorticoid-induced adrenal insufficiency, to investigate its clinical implications, and to identify predictors of risk and prognosis. Randomized trials are required to evaluate whether hydrocortisone replacement therapy mitigates risk and symptoms of glucocorticoid-induced adrenal insufficiency in patients discontinuing glucocorticoid treatment. This review aims to provide an overview of the available evidence, pointing to knowledge gaps and unmet needs.

Some dystrophy phenotypes of dystrophin-deficient mdx mice are exacerbated by mild, repetitive daily stress

Psychosocial stressors can cause physical inactivity, cardiac damage, and hypotension-induced death in the mdx mouse model of Duchenne muscular dystrophy (DMD). Because repeated exposure to mild stress can lead to habituation in wild-type mice, we investigated the response of mdx mice to a mild, daily stress to determine whether habituation occurred. Male mdx mice were exposed to a 30-sec scruff restraint daily for 12 weeks. Scruff restraint induced immediate physical inactivity that persisted for at least 60 minutes, and this inactivity response was just as robust after 12 weeks as it was after one day. Physical inactivity in the mdx mice was not associated with acute skeletal muscle contractile dysfunction. However, skeletal muscle of mdx mice that were repeatedly stressed had slow-twitch and tetanic relaxation times and trended toward high passive stiffness, possibly due to a small but significant increase in muscle fibrosis. Elevated urinary corticosterone secretion, adrenal hypertrophy, and a larger adrenal cortex indicating chronic activation of the hypothalamic-pituitary-adrenal (HPA) axis were measured in 12-week stressed mdx mice relative to those unstressed. However, pharmacological inhibition of the HPA axis did not affect scruff-induced physical inactivity and acute corticosterone injection did not recapitulate the scruff-induced phenotype, suggesting the HPA axis is not the driver of physical inactivity. Our results indicate that the response of mdx mice to an acute mild stress is non-habituating and that when that stressor is repeated daily for weeks, it is sufficient to exacerbate some phenotypes associated with dystrophinopathy in mdx mice.

What we have to know about corticosteroids use during Sars-Cov-2 infection

PURPOSE

Glucocorticoids (GCs), alone or associated to other drugs, were widely used in the management of patients affected by severe acute respiratory syndrome caused by SARS-CoV-2 infection, during the recent COVID-19 outbreak. This review summarizes the available data on HPA axis impairment in GC-treated SARS-CoV-2 patients, focusing on the risk of adrenal insufficiency and on potential drug interactions during concomitant treatments.

METHODS

Literature on the impact of GCs therapy on HPA axis and on the consequences of coadministration of GCs and other drugs in SARS-CoV-2 patients has been reviewed.

RESULTS

GC treatment can cause symptoms of hypercortisolism, especially in patients with individual hypersensibility, or hypoadrenalism after drug withdrawal, due to hypothalamic-pituitary-adrenal (HPA) axis suppression, with consequences in terms of increased morbidity and mortality risk. On the other hand, in SARS-CoV-2-infected patient's cortisol secretion could be insufficient also due to critical illness-related corticosteroid insufficiency (CIRCI). In addition, in this clinical context, the co-administration of antiretroviral drugs and corticosteroids may trigger drug-drug interaction and enhance the exposure to the latter ones, metabolized through the CYP450 CYP3A pathway, severely impacting on HPA axis.

CONCLUSION

Physicians involved in the management of patients affected by COVID-19 should be aware of the need of an appropriate GC dose tapering, and of potential interaction of GCs with antiviral therapy and drugs used to treat associated co-morbidities.

MANAGEMENT OF ENDOCRINE DISEASE: Thyroid and female infertility: more questions than answers?!

Severe thyroid dysfunction may lead to menstrual disorders and infertility via direct and indirect interactions with the hypothalamo-pituitary-ovarian axis and the reproductive organs. However, the exact prevalence of infertility in women with thyroid disorders remains unknown. Fertility problems may persist even after restoring normal thyroid function, and then surgery and/or an assisted reproductive technology (ART) may be necessary to obtain a pregnancy. The initial step in an ART treatment is the ovarian stimulation, putting strain on the thyroid gland, potentially leading to (permanent) hypothyroidism in women with thyroid autoimmunity (TAI) or when already treated with thyroid hormones (LT4). Moreover, women with ovarian and unexplained causes of infertility have a higher prevalence of TAI. In women treated with LT4, a serum TSH level <2.5 mIU/L should be targeted before ART. In women with TSH levels >4.0 mIU/L, fertilisation rates, embryo quality and live birth rates may be impaired but also improved with LT4 therapy. In euthyroid women with TAI, LT4 should not be given systematically, but on a case-by-case basis if serum TSH is >2.5 mIU/L. For all of the above reasons, women of infertile couples should be screened routinely for the presence of thyroid disorders. In this review, we will focus on the gaps in the current knowledge, the remaining questions on the associations between thyroid (disorders) and (assisted) reproduction and make proposals for future investigations that may lead to a better understanding and contribute to novel treatment options in the long term.

Case Report: SARS-CoV-2 Infection in a Child With Suprasellar Tumor and Hypothalamic-Pituitary Failure

In early 2020, a novel coronavirus leading to potentially death was discovered. Since then, the 2019 coronavirus disease (COVID-19) has spread to become a worldwide pandemic. Beyond the risks strictly related to the infection, concerns have been expressed for the endocrinological impact that COVID-19 may have, especially in vulnerable individuals with pre-existing endocrinological health conditions. To date new information is emerging regarding severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) in children but the literature is still scarce concerning this infection in patients with intracranial malignant neoplasms. We report a 9-year-old child infected with SARS-CoV-2 and recent diagnosis of suprasellar non-germinomatous germ cell tumor also suffering from diabetes insipidus and hypothalamic-pituitary failure (hypothyroidism, adrenal insufficiency, hypothalamic obesity and growth hormone deficiency) and its clinical course. The patient remained asymptomatic for the duration of the infection without requiring any change in the replacement therapeutic dosages taken before the infection. We then discuss the proposed approach to treat a pediatric patient with SARS-CoV-2 infection and hypothalamic-pituitary failure and we include a review of the literature. Our report suggests that SARS-CoV-2 infection is usually mild and self-limiting in children even those immunocompromised and with multiple endocrinological deficits. Patients are advised to keep any scheduled appointments unless informed otherwise.

The effects of psychobiotics on the microbiota-gut-brain axis in early-life stress and neuropsychiatric disorders

Psychobiotics are considered among potential avenues for modulating the bidirectional communication between the gastrointestinal tract and central nervous system, defined as the microbiota-gut-brain axis (MGBA). Even though causality has not yet been established, intestinal dysbiosis has emerged as a hallmark of several diseases, including neuropsychiatric disorders (NPDs). The fact that the microbiota and central nervous system are co-developing during the first years of life has provided a paradigm suggesting a potential role of psychobiotics for earlier interventions. Studies in animal models of early-life stress (ELS) have shown that they can counteract the pervasive effects of stress during this crucial developmental period, and rescue behavioral symptoms related to anxiety and depression later in life. In humans, evidence from clinical studies on the efficacy of psychobiotics at improving mental outcomes in most NPDs remain limited, except for major depressive disorder for which more studies are available. Consequently, the beneficial effect of psychobiotics on depression-related outcomes in adults are becoming clearer. While the specific mechanisms at play remain elusive, the effect of psychobiotics are generally considered to involve the hypothalamic-pituitary-adrenal axis, intestinal permeability, and inflammation. It is anticipated that future clinical studies will explore the potential role of psychobiotics at mitigating the risk developing NPDs in vulnerable individuals or in the context of childhood adversity. However, such studies remain challenging at present in terms of design and target populations; the profound impact of stress on the proper development of the MGBA during the first year of life is becoming increasingly recognized, but the trajectories post-ELS in humans and the mechanisms by which stress affects the susceptibility to various NPDs are still ill-defined. As psychobiotics are likely to exert both shared and specific mechanisms, a better definition of target subpopulations would allow to tailor psychobiotics selection by aligning mechanistic properties with known pathophysiological mechanisms or risk factors. Here we review the available evidence from clinical and preclinical studies supporting a role for psychobiotics at ameliorating depression-related outcomes, highlighting the knowledge gaps and challenges associated with conducting longitudinal studies to address outstanding key questions in the field.

The Hypothalamic-Pituitary-Thyroid Axis in Cushing Syndrome Before and After Curative Surgery

BACKGROUND

We do not fully understand how hypercortisolism causes central hypothyroidism or what factors influence recovery of the hypothalamic-pituitary-thyroid axis. We evaluated thyroid function during and after cure of Cushing syndrome (CS).

METHODS

We performed a retrospective cohort study of adult patients with CS seen from 2005 to 2018 (cohort 1, c1, n = 68) or 1985 to 1994 (cohort 2, c2, n = 55) at a clinical research center. Urine (UFC) and diurnal serum cortisol (F: ~8 am and ~midnight [pm]), morning 3,5,3'-triiodothyronine (T3), free thyroxine (FT4), and thyrotropin (TSH) (c1) or hourly TSH from 1500 to 1900 h (day) and 2400 to 04000 h (night) (c2), were measured before and after curative surgery.

RESULTS

While hypercortisolemic, 53% of c1 had central hypothyroidism (low/low normal FT4 + unelevated TSH). Of those followed long term, 31% and 44% had initially subnormal FT4 and T3, respectively, which normalized 6 to 12 months after cure. Hypogonadism was more frequent in hypothyroid (69%) compared to euthyroid (13%) patients. Duration of symptoms, morning and midnight F, adrenocorticotropin, and UFC were inversely related to TSH, FT4, and/or T3 levels (r = -0.24 to -0.52, P < .001 to 0.02). In c2, the nocturnal surge of TSH (mIU/L) was subnormal before (day 1.00 ± 0.04 vs night 1.08 ± 0.05, P = .3) and normal at a mean of 8 months after cure (day 1.30 ± 0.14 vs night 2.17 ± 0.27, P = .01). UFC greater than or equal to 1000 μg/day was an independent adverse prognostic marker of time to thyroid hormone recovery.

CONCLUSIONS

Abnormal thyroid function, likely mediated by subnormal nocturnal TSH, is prevalent in Cushing syndrome and is reversible after cure.

MANAGEMENT OF ENDOCRINE DISEASE: Gonadal dysfunction in congenital adrenal hyperplasia

Gonadal dysfunction is an adverse outcome in patients with congenital adrenal hyperplasia (CAH), which may become apparent already during puberty. Clinical consequences of gonadal dysfunction include menstrual disturbances in females and hypogonadism and impaired fertility in males and females. In males, gonadal dysfunction can be caused by primary gonadal failure due to testicular adrenal rest tumours (TART), and by secondary gonadal failure due to poor hormonal control. In females, gonadal dysfunction can result from an overproduction of adrenal androgens including 11-oxygenated C-19 androgens and progestins, and rarely from ovarian adrenal rest tumours. In all patients with CAH, optimal hormonal control is the key for adequate gonadal function. Therefore, regular measurements of adrenal steroids and/or their metabolites should be performed. In addition, markers of the hypothalamus-pituitary-gonadal axis need to be assessed. In females, the regularity of the menstrual cycle should be evaluated. In males, regular evaluation for TART using ultrasonography is recommended from the start of puberty or even earlier when poor hormonal control is present. When TART is present, counselling on cryopreservation of semen should be offered.

Long term effects of early life stress on HPA circuit in rodent models

Adaptation to environmental challenges represents a critical process for survival, requiring the complex integration of information derived from both external cues and internal signals regarding current conditions and previous experiences. The Hypothalamic-pituitary-adrenal axis plays a central role in this process inducing the activation of a neuroendocrine signaling cascade that affects the delicate balance of activity and cross-talk between areas that are involved in sensorial, emotional, and cognitive processing such as the hippocampus, amygdala, Prefrontal Cortex, Ventral Tegmental Area, and dorsal raphe. Early life stress, especially early critical experiences with caregivers, influences the functional and structural organization of these areas, affects these processes in a long-lasting manner and may result in long-term maladaptive and psychopathological outcomes, depending on the complex interaction between genetic and environmental factors. This review summarizes the results of studies that have modeled this early postnatal stress in rodents during the first 2 postnatal weeks, focusing on the long-term effects on molecular and structural alteration in brain areas involved in Hypothalamic-pituitary-adrenal axis function. Moreover, a brief investigation of epigenetic mechanisms and specific genetic targets mediating the long-term effects of these early environmental manipulations and at the basis of differential neurobiological and behavioral effects during adulthood is provided.

The Role of Hypothalamic Inflammation in Diet-Induced Obesity and Its Association with Cognitive and Mood Disorders

Obesity is often associated with cognitive and mood disorders. Recent evidence suggests that obesity may cause hypothalamic inflammation. Our aim was to investigate the hypothesis that there is a causal link between obesity-induced hypothalamic inflammation and cognitive and mood disorders. Inflammation may influence hypothalamic inter-connections with regions important for cognition and mood, while it may cause dysregulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis and influence monoaminergic systems. Exercise, healthy diet, and glucagon-like peptide receptor agonists, which can reduce hypothalamic inflammation in obese models, could improve the deleterious effects on cognition and mood.

Pathophysiological implications of neuroinflammation mediated HPA axis dysregulation in the prognosis of cancer and depression

Cancer patients are more likely to develop depressive symptoms and show a poor prognosis compared to the normal healthy individuals. Cancer occurrence and the anticancer treatments result in the pro-inflammatory cytokines-mediated inflammation, which dysregulates the HPA-axis activity that may result in depression-like behaviour. Conversely, depression causes the activation of the HPA-axis that results in the downstream release of endogenous glucocorticoids which may result in depressive signs and symptoms in some cancer patients. Depression may also result in non-adherence to treatment and increased mortality in cancer patients. In this review, we have focused on the role of neuroimmune axis and hyperactive HPA-axis in case of both cancer and depression. Therefore, therapeutics targeting the HPA-axis dysregulation could be effective in ameliorating symptoms of depression in cancer patients.

Cortisol Co-Secretion and Clinical Usefulness of ACTH Stimulation Test in Primary Aldosteronism: A Systematic Review and Biases in Epidemiological Studies

The hypothalamus-pituitary-adrenal (HPA) axis plays an important role in primary aldosteronism. Aldosterone biosynthesis is regulated not only by angiotensin II in the renin-angiotensin-aldosterone system, but also by adrenocorticotropic hormone (ACTH), one of the key components of the HPA axis. Although previous studies have reported cortisol cosecretion in primary aldosteronism, particularly aldosterone-producing adenoma (APA), the clinical relevance of such aldosterone and cortisol cosecretion from APA and hypertension or other metabolic disorders has not been fully established. Several somatic mutations including KCNJ5 and CACNA1D are known to induce autonomous production of aldosterone in APA, and the aldosterone responsiveness to ACTH may vary according to each mutation. The ACTH stimulation test has been reported to be a useful tool to distinguish the subtypes of primary aldosteronism (e.g., unilateral vs bilateral) in some studies, but it has not been commonly applied in clinical practice due to limited evidence. Given the recent advancement of imaging, omics research, and computational approach, it is important to summarize the most updated evidence to disentangle the potential impact of cortisol excess in primary aldosteronism and whether the ACTH stimulation test needs to be considered during the diagnostic process of primary aldosteronism. In this article, we conducted a systematic review of epidemiological studies about (i) cortisol cosecretion in primary aldosteronism and (ii) the ACTH stimulation test for the diagnosis of primary aldosteronism (including subtype diagnosis). Then, we discussed potential biases (e.g., confounding bias, overadjustment, information bias, selection bias, and sampling bias) in the previous studies and introduced some advanced epidemiological/statistical methods to minimize these limitations. A better understanding of biases and epidemiological perspective on this topic would allow us to produce further robust evidence and balanced discussion about the causal mechanisms involving the HPA axis and clinical usefulness of the ACTH stimulation test among patients with primary aldosteronism.

Hyperprolactinemia and Hypopituitarism in Acromegaly and Effect of Pituitary Surgery: Long-Term Follow-up on 529 Patients

PURPOSE

Studies on hyperprolactinemia and hypopituitarism in acromegaly are limited. We aimed to analyze the preoperative status, postoperative alterations, and correlated factors of hyperprolactinemia and hypopituitarism in acromegaly patients.

METHODS

This is a single-center cohort study with long-term follow-up. We prospectively enrolled 529 acromegaly patients. Hyperprolactinemia and hypopituitarism were evaluated by testing hypothalamus-pituitary-end organ (HPEO) axes hormones before and after surgery.

RESULTS

Hyperprolactinemia (39.1%) and hypopituitarism (34.8%) were common in acromegaly. The incidences of axis-specific hypopituitarism varied (hypogonadism, 29.7%; hypothyroidism, 5.9%; adrenal insufficiency, 5.1%), and multiple HPEO axes dysfunction was diagnosed in 5.3% of patients. Patients with preoperative hyperprolactinemia [hazard ratio (HR)=1.39 (1.08-1.79); p=0.012], hypogonadism [HR=1.32 (1.01-1.73); p=0.047], and hypothyroidism [HR=3.49 (1.90-6.44); p<0.001] had higher recurrence rates than those without. Age, sex, body mass index, tumor size, invasiveness, prolactin staining, ki-67 index, and GH/IGF-1 levels were significantly correlated with preoperative hypopituitarism and hyperprolactinemia. At median 34-month follow-up after surgery, hyperprolactinemia in 95% and axis-specific hypopituitarism in 54%-71% of patients recovered, whereas new-onset hypopituitarism (hypogonadism, 6.2%; hypothyroidism, 4.0%; adrenal insufficiency, 3.2%) was also diagnosed. A shorter tumor diameter was associated with the normalization of preoperative hyperprolactinemia after surgery. Cavernous sinus non-invasion, a shorter tumor diameter, cure at follow-up, and a lower GH nadir level were associated with the improvement of preoperative hypopituitarism after surgery. A larger tumor diameter was associated with the newly developed hypopituitarism after surgery.

CONCLUSION

Hyperprolactinemia and hypopituitarism are common among acromegaly patients and predict worse surgical outcomes. After surgery, improvement and worsening of HPEO axes function co-exist. Correlated factors are identified for clinical management.

The nonhuman primate hypothalamo-pituitary-adrenal axis is an orchestrator of programming-aging interactions: role of nutrition

Developmental programming alters life-course multi-organ function and significantly affects life-course health. Recently, interest has developed in how programming may influence the rate of aging. This review describes interactions of nutrition and programming-aging interactions in hypothalamo-pituitary-adrenal (HPA) development and function from fetal development to old age. A full picture of these interactions requires data on levels of HPA activity relating to the hypothalamic, adrenal cortical, circulating blood, and peripheral cortisol metabolism. Data are provided from studies on our baboon, nonhuman primate model both across the normal life course and in offspring of maternal baboons who were moderately undernourished by a global 30% diet reduction during pregnancy and lactation. Sex differences in offspring outcomes in response to similar challenges are described. The data clearly show programming of increased HPA axis activity by moderate maternal undernutrition. Increased postnatal circulating cortisol concentrations are related to accelerated aging of the brain and cardiovascular systems. Future studies should address peripheral cortisol production and the influence of aging advantage in females. These data support the view that the HPA is an orchestrator of interactions of programming-aging mechanisms.

Low-dose ACTH test for evaluation of hypothalamus-pituitary-adrenal axis preoperatively and 3-month follow-up in non-functioning pituitary adenomas

BACKGROUND

Peri-operative glucocorticoids are routinely administered to patients undergoing trans-sphenoidal surgery for non-functional pituitary adenomas (NFPA) irrespective of hypothalamus-pituitary-adrenal (HPA) axis status.

PURPOSE

Evaluation of HPA axis before and 12 weeks after endoscopic trans-sphenoidal adenomectomy (E-TSA) utilizing low-dose (1 μg) ACTH stimulation test (LDACTH) to determine the need for glucocorticoid administration in patients with NFPA. We also determined the factors that can predict occurrence of hypocortisolism at 12 weeks after surgery.

METHODS

Sixty-three consecutive patients with NFPA requiring surgical excision were enrolled in this study. Glucocorticoids were administered to patients with demonstrable hypocortisolism [preoperative peak cortisol < 16 μg/dL during LDACTH test, postoperative day 3 (POD-3) 0800 hrs Cortisol < 8 μg/dL or stimulated cortisol (LDACTH) < 16 μg/dL at 12 weeks].

RESULTS

Hypocortisolism was present in 43 patients (68.2%) pre-operatively and persisted in 33 patients (52.4%) on POD-3. Thirty-three patients (52.4%) had hypocortisolism at 12 weeks after surgery. Eleven patients (17.4%) did not require glucocorticoids during the entire study period and 30 patients (47.6%) did not require glucocorticoids after 3 months. None of the patients developed adrenal crisis during the study. Hypocortisolism on the third post-operative day was the single significant predictor of hypocortisolism at 12 weeks after the surgery. There was a significant correlation between POD-3 0800 hrs cortisol ≥ 8μg/dL and stimulated cortisol (LDACTH) ≥16μg/dL at 12 weeks (r = 0.62, p < 0.0001). POD-3 0800 hrs cortisol ≥ 8 μg/dL had 73% sensitivity and 79% specificity in predicting eucortisolism at 12 weeks.

CONCLUSIONS

HPA function is preserved in significant proportion of NFPA patients undergoing E-TSA. Perioperative glucocorticoids should be given only in patients with demonstrable preoperative hypocortisolism on 1 μg ACTH test. Postoperative day 3 0800 hrs cortisol is a reasonable predictor of HPA axis status at 12 weeks after surgery.

Molecular insights into the divergence and diversity of post-testicular maturation strategies

Competition to achieve paternity has coerced the development of a multitude of male reproductive strategies. In one of the most well-studied examples, the spermatozoa of all mammalian species must undergo a series of physiological changes as they transit the male (epididymal maturation) and female (capacitation) reproductive tracts prior to realizing their potential to fertilize an ovum. However, the origin and adaptive advantage afforded by these intricate processes of post-testicular sperm maturation remain to be fully elucidated. Here, we review literature pertaining to the nature and the physiological role of epididymal maturation and subsequent capacitation in comparative vertebrate taxa including representative species from the avian, reptilian, and mammalian lineages. Such insights are discussed in terms of the framework they provide for helping to understand the evolutionary significance of post-testicular sperm maturation.

Impact of Acute and Chronic Stress on Thrombosis in Healthy Individuals and Cardiovascular Disease Patients

Psychological stress induces different alterations in the organism in order to maintain homeostasis, including changes in hematopoiesis and hemostasis. In particular, stress-induced hyper activation of the autonomic nervous system and hypothalamic–pituitary–adrenal axis can trigger cellular and molecular alterations in platelets, coagulation factors, endothelial function, redox balance, and sterile inflammatory response. For this reason, mental stress is reported to enhance the risk of cardiovascular disease (CVD). However, contrasting results are often found in the literature considering differences in the response to acute or chronic stress and the health condition of the population analyzed. Since thrombosis is the most common underlying pathology of CVDs, the comprehension of the mechanisms at the basis of the association between stress and this pathology is highly valuable. The aim of this work is to give a comprehensive review of the studies focused on the role of acute and chronic stress in both healthy individuals and CVD patients, focusing on the cellular and molecular mechanisms underlying the relationship between stress and thrombosis.

Variant-to-Gene-Mapping Analyses Reveal a Role for the Hypothalamus in Genetic Susceptibility to Inflammatory Bowel Disease

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) is a polygenic disorder characterized principally by dysregulated inflammation impacting the gastrointestinal tract. However, there also is increasing evidence for a clinical association with stress and depression. Given the role of the hypothalamus in stress responses and in the pathogenesis of depression, useful insights could be gleaned from understanding its genetic role in IBD.

METHODS

We conducted genetic correlation analyses on publicly available genome-wide association study summary statistics for depression and IBD traits to identify genetic commonalities. We used partitioned linkage disequilibrium score regression, leveraging our ATAC sequencing and promoter-focused Capture C data, to measure enrichment of IBD single-nucleotide polymorphisms within promoter-interacting open chromatin regions of human embryonic stem cell-derived hypothalamic-like neurons (HNs). Using the same data sets, we performed variant-to-gene mapping to implicate putative IBD effector genes in HNs. To contrast these results, we similarly analyzed 3-dimensional genomic data generated in epithelium-derived colonoids from rectal biopsy specimens from donors without pathologic disease noted at the time of colonoscopy. Finally, we conducted enrichment pathway analyses on the implicated genes to identify putative IBD dysfunctional pathways.

RESULTS

We found significant genetic correlations (rg) of 0.122 with an adjusted P (Padj) = 1.4 × 10-4 for IBD: rg = 0.122; Padj = 2.5 × 10-3 for ulcerative colitis and genetic correlation (rg) = 0.094; Padj = 2.5 × 10-3 for Crohn's disease, and significant approximately 4-fold (P = .005) and approximately 7-fold (P = .03) enrichment of IBD single-nucleotide polymorphisms in HNs and colonoids, respectively. We implicated 25 associated genes in HNs, among which CREM, CNTF, and RHOA encode key regulators of stress. Seven genes also additionally were implicated in the colonoids. We observed an overall enrichment for immune and hormonal signaling pathways, and a colonoid-specific enrichment for microbiota-relevant terms.

CONCLUSIONS

Our results suggest that the hypothalamus warrants further study in the context of IBD pathogenesis.

Undernutrition and Pubertal Timing in Female Survivors of Medulloblastoma and Other Embryonal Tumors

CONTEXT

Children with brain tumors may have pubertal onset at an inappropriately young chronologic age. Hypothalamic-pituitary irradiation ≥18Gy has been found to be a risk factor; age at irradiation is associated with pubertal timing. However, the underlying mechanisms are unknown.

OBJECTIVE

To determine the impact of body mass index (BMI) and catch-up growth on pubertal timing in females treated for medulloblastoma and other embryonal tumors.

DESIGN, SETTING, AND PATIENTS

Retrospective cohort analysis of 90 female patients treated for medulloblastoma and other embryonal tumors at Dana-Farber Cancer Institute/Boston Children's Hospital from 1996 to 2016. Eighteen individuals met inclusion criteria, with a mean ± SD follow-up period of 11.9 ± 3.4 years.

MAIN OUTCOME MEASURES

Multiple linear regression models for age at pubertal onset and bone age discrepancy from chronologic age at pubertal onset assessed the joint influences of age at irradiation, hypothalamic irradiation dose, undernutrition duration, BMI standard deviation score (SDS) at pubertal onset, and catch-up BMI SDS.

RESULTS

The mean ± SD age of pubertal onset was 9.2 ± 1.3 years and hypothalamic radiation dose was 31.9 ± 9.9 Gy. There was a direct relationship between age at irradiation and age at pubertal onset (β = 0.323 ± 0.144 [standard error] year per year; P = 0.04) that was significantly attenuated after adjusting for BMI SDS at pubertal onset (P = 0.5) and catch-up BMI SDS (P = 0.08), suggesting that BMI is a mediator.

CONCLUSIONS

Both absolute and catch-up BMI SDS at pubertal onset are significant mediators of pubertal timing and bone age discrepancy in pediatric medulloblastoma and other embryonal tumors, and thus, are targetable risk factors to optimize pubertal timing.

Effects of Early-Life Stress on the Brain and Behaviors: Implications of Early Maternal Separation in Rodents

Early-life stress during the prenatal and postnatal periods affects the formation of neural networks that influence brain function throughout life. Previous studies have indicated that maternal separation (MS), a typical rodent model equivalent to early-life stress and, more specifically, to child abuse and/or neglect in humans, can modulate the hypothalamic-pituitary-adrenal (HPA) axis, affecting subsequent neuronal function and emotional behavior. However, the neural basis of the long-lasting effects of early-life stress on brain function has not been clarified. In the present review, we describe the alterations in the HPA-axis activity-focusing on serum corticosterone (CORT)-and in the end products of the HPA axis as well as on the CORT receptor in rodents. We then introduce the brain regions activated during various patterns of MS, including repeated MS and single exposure to MS at various stages before weaning, via an investigation of c-Fos expression, which is a biological marker of neuronal activity. Furthermore, we discuss the alterations in behavior and gene expression in the brains of adult mice exposed to MS. Finally, we ask whether MS repeats itself and whether intergenerational transmission of child abuse and neglect is possible.

DNA methylation of FKBP5 in South African women: associations with obesity and insulin resistance

BACKGROUND

Disruption of the hypothalamic-pituitary-adrenal (HPA) axis, a neuroendocrine system associated with the stress response, has been hypothesized to contribute to obesity development. This may be mediated through epigenetic modulation of HPA axis-regulatory genes in response to metabolic stressors. The aim of this study was to investigate adipose tissue depot-specific DNA methylation differences in the glucocorticoid receptor (GR) and its co-chaperone, FK506-binding protein 51 kDa (FKBP5), both key modulators of the HPA axis.

METHODS

Abdominal subcutaneous adipose tissue (ASAT) and gluteal subcutaneous adipose tissue (GSAT) biopsies were obtained from a sample of 27 obese and 27 normal weight urban-dwelling South African women. DNA methylation and gene expression were measured by pyrosequencing and quantitative real-time PCR, respectively. Spearman's correlation coefficients, orthogonal partial least-squares discriminant analysis and multivariable linear regression were performed to evaluate the associations between DNA methylation, messenger RNA (mRNA) expression and key indices of obesity and metabolic dysfunction.

RESULTS

Two CpG dinucleotides within intron 7 of FKBP5 were hypermethylated in both ASAT and GSAT in obese compared to normal weight women, while no differences in GR methylation were observed. Higher percentage methylation of the two FKBP5 CpG sites correlated with adiposity (body mass index and waist circumference), insulin resistance (homeostasis model for insulin resistance, fasting insulin and plasma adipokines) and systemic inflammation (c-reactive protein) in both adipose depots. GR and FKBP5 mRNA levels were lower in GSAT, but not ASAT, of obese compared to normal weight women. Moreover, FKBP5 mRNA levels were inversely correlated with DNA methylation and positively associated with adiposity, metabolic and inflammatory parameters.

CONCLUSIONS

These findings associate dysregulated FKBP5 methylation and mRNA expression with obesity and insulin resistance in South African women. Additional studies are required to assess the longitudinal association of FKBP5 with obesity and associated co-morbidities in large population-based samples.

Neuroinflammation-Associated Alterations of the Brain as Potential Neural Biomarkers in Anxiety Disorders

Stress-induced changes in the immune system, which lead to neuroinflammation and consequent brain alterations, have been suggested as possible neurobiological substrates of anxiety disorders, with previous literature predominantly focusing on panic disorder, agoraphobia, and generalized anxiety disorder, among the anxiety disorders. Anxiety disorders have frequently been associated with chronic stress, with chronically stressful situations being reported to precipitate the onset of anxiety disorders. Also, chronic stress has been reported to lead to hypothalamic–pituitary–adrenal axis and autonomic nervous system disruption, which may in turn induce systemic proinflammatory conditions. Preliminary evidence suggests anxiety disorders are also associated with increased inflammation. Systemic inflammation can access the brain, and enhance pro-inflammatory cytokine levels that have been shown to precipitate direct and indirect neurotoxic effects. Prefrontal and limbic structures are widely reported to be influenced by neuroinflammatory conditions. In concordance with these findings, various imaging studies on panic disorder, agoraphobia, and generalized anxiety disorder have reported alterations in structure, function, and connectivity of prefrontal and limbic structures. Further research is needed on the use of inflammatory markers and brain imaging in the early diagnosis of anxiety disorders, along with the possible efficacy of anti-inflammatory interventions on the prevention and treatment of anxiety disorders.

Immune-toxicity effects of scorpion venom on the hypothalamic pituitary adrenal axis during rest and activity phases in a rodent model

Scorpion venom is a complex mixture of peptides and proteins, rich in toxins. Its toxicological effects are related to central disruptions and autonomic disturbances, organ failure, as well as an excessive systemic inflammatory response. Since the role of the hypothalamic pituitary adrenal (HPA) axis is central in the neuroendocrine-immunological axis, the purpose of this study was, therefore, to examine the immunotoxic effect of Androctonus australis hector (Aah) venom on HPA-axis in synchronised-mice model. Taking into account the circadian activity of the HPA-axis, the variations of adrenocorticotropic hormone and corticosterone plasma levels, oxidative stress as well as inflammatory markers in cerebral, hypothalamic and adrenal tissue homogenates were investigated during the rest and activity phases of animals. Histopathology study was also performed. Results showed that Aah venom activated the HPA axis. This response seems to be dependent on time of envenomation, as a higher hormone levels were more operative during the active phase than in the rest phase when compared to time-matched control. The local toxicity-effects following Aah envenomation revealed an imbalance in oxidative stress with a higher antioxidant defences in darkness hypothalamic and cerebral tissues. Furthermore, there were significantly higher levels in vascular permeability in hypothalamic and cerebral tissues accompanied by a concomitant increase in immune-cell infiltration and/or activation as shown by expression of CD68 and myeloperoxidase activity during the active phase compared with the rest phase. Overall results suggested that Aah venom had a toxic impact on different HPA-axis areas and the effect varies according to the time of envenomation.