11β-hydroxysteroid dehydrogenases: intracellular gate-keepers of tissue glucocorticoid action

Modulation by Ozone of Glucocorticoid-Regulating Factors in the Lungs in Relation to Stress Axis Reactivity

Exposure to air pollutants increases levels of circulating glucocorticoid stress hormones that exert profound effects relevant to health and disease. However, the nature and magnitude of tissue-level effects are modulated by factors that regulate local glucocorticoid activity; accordingly, inter-individual differences could contribute to susceptibility. In the present study, we characterized effects of ozone (O₃) inhalation on glucocorticoid-regulating factors in the lungs of rat strains with contrasting hypothalamic–pituitary–adrenal stress axis responses. Hyper-responsive Fischer (F344) and less responsive Lewis (LEW) rats were exposed to air or 0.8 ppm O₃ for 4 h by nose-only inhalation. Levels of the high-specificity and -affinity corticosteroid-binding globulin protein increased in the lungs of both strains proportional to the rise in corticosterone levels following O₃ exposure. Ozone reduced the ratio of 11β-hydroxysteroid dehydrogenase type 1 (HSDB1)/HSDB2 mRNA in the lungs of F344 but not LEW, indicating strain-specific transcriptional regulation of the major glucocorticoid metabolism factors that control tissue-level action. Intercellular adhesion molecule (ICAM)-1 and total elastase activity were increased by O₃ in both strains, consistent with extravasation and tissue remodeling processes following injury. However, mRNA levels of inflammatory markers were significantly higher in the lungs of O₃-exposed LEW compared to F344. The data show that strain differences in the glucocorticoid response to O₃ are accompanied by corresponding changes in regulatory factors, and that these effects are collectively associated with a differential inflammatory response to O₃. Innate differences in glucocorticoid regulatory factors may modulate the pulmonary effects of inhaled pollutants, thereby contributing to differential susceptibility.

Rank- and sex-specific differences in the neuroendocrine regulation of glucocorticoids in a wild group-living fish

Individuals that live in groups experience different challenges based on their social rank and sex. Glucocorticoids have a well-established role in coordinating responses to challenges and glucocorticoid levels often vary between ranks and sexes. However, the neuroendocrine mechanisms regulating glucocorticoid dynamics in wild groups are poorly understood, making it difficult to determine the functional consequences of differences in glucocorticoid levels. Therefore, we observed wild social groups of a cooperatively breeding fish (Neolamprologus pulcher) and evaluated how scale cortisol content (an emerging method to evaluate cortisol dynamics in fishes) and expression of glucocorticoid-related genes varied across group members. Scale cortisol was detectable in ~50% of dominant males (7/17) and females (7/15)-but not in any subordinates (0/16)-suggesting that glucocorticoid levels were higher in dominants. However, the apparent behavioural and neuroendocrine factors regulating cortisol levels varied between dominant sexes. In dominant females, higher cortisol was associated with greater rates of territory defense and increased expression of corticotropin-releasing factor in the preoptic and hypothalamic regions of the brain, but these patterns were not observed in dominant males. Additionally, transcriptional differences in the liver suggest that dominant sexes may use different mechanisms to cope with elevated cortisol levels. While dominant females appeared to reduce the relative sensitivity of their liver to cortisol (fewer corticosteroid receptor transcripts), dominant males appeared to increase hepatic cortisol breakdown (more catabolic enzyme transcripts). Overall, our results offer valuable insights on the mechanisms regulating rank- and sex-based glucocorticoid dynamics, as well as the potential functional outcomes of these differences.

Imaging brain cortisol regulation in PTSD with a target for 11β-hydroxysteroid dehydrogenase type 1

BACKGROUNDInvestigations of stress dysregulation in posttraumatic stress disorder (PTSD) have focused on peripheral cortisol, but none have examined cortisol in the human brain. This study used positron emission tomography (PET) to image 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), a cortisol-producing enzyme, as a putative brain cortisol marker in PTSD.METHODSSixteen individuals with PTSD and 17 healthy, trauma-exposed controls (TCs) underwent PET imaging with [18F]AS2471907, a radioligand for 11β-HSD1.RESULTSPrefrontal-limbic 11β-HSD1 availability, estimated as [18F]AS2471907 volume of distribution (VT), was significantly higher in the PTSD group compared with the TC group (β = 1.16, P = 0.0057). Lower prefrontal-limbic 11β-HSD1 availability was related to greater overall PTSD severity (R2 = 0.27, P = 0.038) in the PTSD group. 11β-HSD1 availability was not related to plasma cortisol levels (R2 = 0.026, P = 0.37). In a PTSD subset (n = 10), higher 11β-HSD1 availability was associated with higher availability of translocator protein (TSPO), a microglial marker (β = 4.40, P = 0.039).CONCLUSIONHigher brain cortisol-producing 11β-HSD1 in the PTSD group may represent a resilience-promoting neuroadaptation resulting in lower PTSD symptoms. Along with preliminary associations between 11β-HSD1 and TSPO, corroborating previous evidence of immune suppression in PTSD, these findings collectively challenge previous hypotheses of the deleterious effects of both excessive brain glucocorticoid and brain immune signaling in PTSD.FUNDINGBrain and Behavior Research Foundation Independent Investigator Grant, National Institute of Mental Health grants F30MH116607 and R01MH110674, the Veterans Affairs National Center for PTSD, the Gustavus and Louise Pfeiffer Foundation Fellowship, Clinical and Translational Science Awards grant UL1 TR000142 from the NIH National Center for Advancing Translational Science.

Association between Selected Polymorphisms rs12086634, rs846910, rs4844880, rs3753519 of 11β-Hydroxysteroid Dehydrogenase Type 1 (HSD11B1) and the Presence of Insulin Resistance in the Polish Population of People Living in Upper Silesia

Background: Many factors influence the development of insulin resistance, among other genetic factors. Cortisol is one of the factors that has a significant impact on the development of insulin resistance. The proteins that have a substantial effect on blood cortisol levels include 11β-hydroxysteroid dehydrogenase type 1. HSD11B1 is a microsomal enzyme that catalyzes the conversion of the stress hormone cortisol to the inactive metabolite cortisone. Gene encoding HSD11B1 is located on 1q32.2. This study was designed to assess the association between four polymorphic sides in HSD11B1 (rs12086634, rs846910, rs4844880, rs3753519) between subjects with and without insulin resistance in the Polish population of people living in Upper Silesia. Methods: The study included a total of 507 consecutive patients, 374 (73.77%) with and 133 (26.23%) without insulin resistance. Results: The results show that there were no statistically significant differences in the distribution of genotypes and alleles of the examined polymorphisms of the 11β-hydroxysteroid dehydrogenase type 1 gene between subjects with and without insulin resistance (determined using the HOMA-IR, insulin resistance index) and that rs846910 and rs1208663 polymorphisms of the 11β-hydroxysteroid dehydrogenase type 1 gene in the examined subjects have a significant effect on the magnitude of the HOMA-IR insulin resistance index. Conclusions: The study results suggested that genetic variation of rs846910 and rs1208663 polymorphism of the HSD11B1 gene is related to the susceptibility to insulin resistance. Our results provide a basis to begin basic research on the role of the HSD11B1 gene in the pathogenesis of insulin resistance.

The poorly conducted orchestra of steroid hormones, oxidative stress and inflammation in frailty needs a maestro: Regular physical exercise

This review outlines the various factors associated with unhealthy aging which includes becoming frail and dependent. With many people not engaging in recommended exercise, facilitators and barriers to engage with exercise must be investigated to promote exercise uptake and adherence over the lifespan for different demographics, including the old, less affluent, women, and those with different cultural-ethnic backgrounds. Governmental and locally funded public health messages and environmental facilitation (gyms, parks etc.) can play an important role. Studies have shown that exercise can act as a conductor to balance oxidative stress, immune and endocrine functions together to promote healthy aging and reduce the risk for age-related morbidities, such as cardiovascular disease and atherosclerosis, and promote cognition and mood over the lifespan. Like a classic symphony orchestra, consisting of four groups of related musical instruments - the woodwinds, brass, percussion, and strings - the aging process should also perform in harmony, with compassion, avoiding the aggrandizement of any of its individual parts during the presentation. This review discusses the wide variety of molecular, cellular and endocrine mechanisms (focusing on the steroid balance) underlying this process and their interrelationships.

Glucocorticoid Resistance: Interference between the Glucocorticoid Receptor and the MAPK Signalling Pathways

Endogenous glucocorticoids (GCs) are steroid hormones that signal in virtually all cell types to modulate tissue homeostasis throughout life. Also, synthetic GC derivatives (pharmacological GCs) constitute the first-line treatment in many chronic inflammatory conditions with unquestionable therapeutic benefits despite the associated adverse effects. GC actions are principally mediated through the GC receptor (GR), a ligand-dependent transcription factor. Despite the ubiquitous expression of GR, imbalances in GC signalling affect tissues differently, and with variable degrees of severity through mechanisms that are not completely deciphered. Congenital or acquired GC hypersensitivity or resistance syndromes can impact responsiveness to endogenous or pharmacological GCs, causing disease or inadequate therapeutic outcomes, respectively. Acquired GC resistance is defined as loss of efficacy or desensitization over time, and arises as a consequence of chronic inflammation, affecting around 30% of GC-treated patients. It represents an important limitation in the management of chronic inflammatory diseases and cancer, and can be due to impairment of multiple mechanisms along the GC signalling pathway. Among them, activation of the mitogen-activated protein kinases (MAPKs) and/or alterations in expression of their regulators, the dual-specific phosphatases (DUSPs), have been identified as common mechanisms of GC resistance. While many of the anti-inflammatory actions of GCs rely on GR-mediated inhibition of MAPKs and/or induction of DUSPs, the GC anti-inflammatory capacity is decreased or lost in conditions of excessive MAPK activation, contributing to disease susceptibility in tissue- and disease- specific manners. Here, we discuss potential strategies to modulate GC responsiveness, with the dual goal of overcoming GC resistance and minimizing the onset and severity of unwanted adverse effects while maintaining therapeutic potential.

Transient expansion of the expression region of Hsd11b1, encoding 11β-hydroxysteroid dehydrogenase type 1, in the developing mouse neocortex

Corticosteroids are stress-related hormones that maintain homeostasis. The most effective corticosteroids are corticosterone (CORT) in rodents and cortisol in primates. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1; EC 1.1.1.146), encoded by Hsd11b1, is a key regulator of the local concentration of CORT/cortisol. Hsd11b1 expression in layer 5 of the primary somatosensory cortex has been shown in adult mice. However, its localization in the entire neocortex, especially during development, has not been fully addressed. Here, we established robust and dynamic expression profiles of Hsd11b1 in the developing mouse neocortex. Hsd11b1 was found mostly in pyramidal neurons. By retrograde tracing, we observed that some Hsd11b1-positive cells were projection neurons, indicating that at least some were excitatory. At postnatal day 0 (P0), Hsd11b1 was expressed in the deep layer of the somatosensory cortex. Then, from P3 to P8, the expression area expanded broadly; it was observed in layers 4 and 5, spanning the whole neocortex, including the primary motor cortex (M1) and the primary visual cortex (V1). The positive region gradually narrowed from P14 onwards and was ultimately limited to layer 5 of the somatosensory cortex at P26 and later. Furthermore, we administered CORT to nursing dams to increase the systemic CORT level of their pups. Here, we observed a reduced number of Hsd11b1-positive cells in the neocortex of these pups. Our observation suggests that Hsd11b1 expression in the developing neocortex is affected by systemic CORT levels. It is possible that stress on mothers influences the neocortical development of their children.

Turning the spotlight on the C11-oxy androgens in human fetal development

Research into the biosynthesis of C11-oxy C₁₉ steroids during human fetal development, specifically fetal adrenal development and during the critical period of sex differentiation, is currently lacking. Cortisol, which possesses a C11-hydroxyl moiety has, however, been firmly established in this context. Compelling questions are whether the C11-oxy C₁₉ steroids (11β-hydroxyandrostenedione, 11β-hydroxytestosterone, 11-ketoandrostenedione and 11-ketotestosterone [11KT]) and the C11-oxy C₂₁ steroids (11β-hydroxyprogesterone and 11-ketoprogesterone) are biosynthesised during gestation, and whether these hormones circulate between the placenta and the developing fetus, and between the placenta and the mother. This review will consider the role of cortisol, 11KT and 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) in determining the sex of teleost fish, while these hormones and 11βHSD2 will also be discussed with regards to murine mammals. The focus of the review will shift to highlight the potential role of C11-oxy steroids in human fetal development based on the timely expression of steroidogenic enzymes in the adrenal, testes and ovary, as well as in the placenta; summarising reported evidence of C11-oxy steroids in neonatal life.

Comparative Profiling of Salivary Cortisol and Salivary DHEA-S Among Healthy Pregnant and Non-Pregnant Women

During pregnancy, circulatory cortisol levels increase, remaining steady over the second-third trimester. In contrast, profile of salivary cortisol during pregnancy is debatable, more influenced by factors like time of sample collection in the day. Circulatory DHEA-S decrease by at least 50% over the second-third trimester of pregnancy. However, profile of salivary DHEA-S is unclear. Objective was to determine changes in salivary cortisol and DHEA-S in healthy pregnant women, compared to non-pregnant women during late morning-early afternoon sampling to avoid fluctuations associated with other times. Pregnant women in their second-third trimester prospectively (n=500) and non-pregnant women (n=133) were enrolled in study with informed consent. Live birth outcome with no pregnancy complications and≥2.5 Kg infant birth weight were included. Concentrations of salivary cortisol and DHEA-S were determined through ELISA assays. Compared to non-pregnant women, pregnant women demonstrated significant increases in salivary cortisol [median (interquartile range)=4.2 (5.1) nmol/l vs. 17.2 (13.9) nmol/l, p<0.001] and salivary DHEA-S median (interquartile range)=2.7 (2.9) nmol/l vs. 3.8 (3.2) nmol/l, p<0.001). Consistently, quartile scores representing higher levels of salivary cortisol and DHEA-S concentrations demonstrated significant association with pregnancy. Quartile scores representing higher salivary cortisol/DHEA-S ratio demonstrated significant association with pregnancy. Study suggests the indicated time range of saliva sampling might best parallel the established profile of circulatory cortisol in pregnant women. However, unlike cortisol, study indicates that the salivary DHEA-S profile is distinct from the well-known profile of circulatory DHEA-S during pregnancy. A combinatorial approach involving both salivary and circulatory compartments could provide comprehensive picture of DHEA-S and hypothalamus-pituitary-adrenal axis during pregnancy.

Effect of Preterm Birth on Cardiac and Cardiomyocyte Growth and the Consequences of Antenatal and Postnatal Glucocorticoid Treatment

Preterm birth coincides with a key developmental window of cardiac growth and maturation, and thus has the potential to influence long-term cardiac function. Individuals born preterm have structural cardiac remodelling and altered cardiac growth and function by early adulthood. The evidence linking preterm birth and cardiovascular disease in later life is mounting. Advances in the perinatal care of preterm infants, such as glucocorticoid therapy, have improved survival rates, but at what cost? This review highlights the short-term and long-term impact of preterm birth on the structure and function of the heart and focuses on the impact of antenatal and postnatal glucocorticoid treatment on the immature preterm heart.

New insights into the roles of glucocorticoid signaling dysregulation in pathological cardiac hypertrophy

Pathological cardiac hypertrophy is a process of abnormal remodeling of the myocardium in response to stress overload or ischemia that results in myocardial injury, which is an independent risk factor for the increased morbidity and mortality of heart failure. Elevated circulating glucocorticoids (GCs) levels are associated with an increased risk of pathological cardiac hypertrophy, but the exact role remains unclear. In the heart, GCs exerts physiological and pharmacological effects by binding the glucocorticoid receptor (GR, NR3C1). However, under the state of tissue damage or oxidative stress, GCs can also bind the closely related mineralocorticoid receptor (MR, NR3C2) to exert a detrimental effect on cardiac function. In addition, the bioavailability of GCs at the cellular level is mainly regulated by tissue-specific metabolic enzymes 11β-hydroxysteroid dehydrogenases (11β-HSDs), including 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) and type 2 (11β-HSD2), which catalyze the interconversion of active GCs. In this paper, we provide an overview of GC signaling and its physiological roles in the heart and highlight the dynamic and diverse roles of GC signaling dysregulation, mediated by excessive ligand GCs levels, GR/MR deficiency or overexpression, and local GCs metabolic disorder by 11β-HSDs, in the pathology of cardiac hypertrophy. Our findings will provide new ideas and insights for the search for appropriate intervention targets for pathological cardiac hypertrophy.

Parental cannabis and tobacco use during pregnancy and childhood hair cortisol concentrations

BACKGROUND

Fetal exposure to cannabis and tobacco during pregnancy leads to adverse fetal and childhood outcomes. We hypothesized that fetal exposure to cannabis and tobacco have persistent programming effects on hypothalamic pituitary adrenal (HPA) axis functioning in childhood. Therefore, we examined the associations of parental cannabis and tobacco use during pregnancy with childhood hair cortisol and cortisone concentrations at 6 years, as biomarkers of long-term HPA-axis functioning.

METHOD

In a population-based prospective birth cohort among 2577 mothers and their children, information of parental cannabis and tobacco use was collected by questionnaires, and maternal urine samples were additionally analyzed to detect cannabis metabolite concentrations. Cortisol and cortisone were measured in hair samples at 6 years. Linear regression analysis with adjustment for several confounders was used to test our hypothesis.

RESULTS

As compared to non-exposed children, offspring exposed to cannabis during pregnancy (in combination with tobacco) had higher childhood cortisol concentrations (log-10 transformed difference 0.16, 95 % Confidence Interval 0.04 to 0.28). This association was not mediated by birth weight. No differences in cortisone concentrations among cannabis-exposed children were observed. Maternal tobacco use during pregnancy was not associated with childhood cortisol or cortisone concentrations. Further, paternal cannabis or tobacco use was not associated with childhood cortisol or cortisone concentrations.

CONCLUSIONS

Our findings suggest that maternal cannabis use, combined with tobacco, during pregnancy is associated with alterations in offspring HPA-axis functioning. Further studies need to replicate these findings, and assess the causality and long-term consequences of these associations.

Ozone-dependent increases in lung glucocorticoids and macrophage response: Effect modification by innate stress axis function

Although considerable inter-individual variability exists in health effects associated with air pollutant exposure, underlying reasons remain unclear. We examined whether innate differences in stress axis function modify lung glucocorticoid and macrophage responses to ozone (O3). Highly-stress responsive Fischer (F344) and less responsive Lewis (LEW) rats were exposed for 4 h by nose-only inhalation to air or O3 (0.8 ppm). Ozone increased corticosterone recovered by bronchoalveolar lavage in both strains (F344 > LEW). Higher corticosterone in F344 was associated with a blunted response to O3 of macrophage pro-inflammatory genes compared to LEW. Pharmacological inhibition of O3-dependent corticosterone production in F344 enhanced the inflammatory gene response to O3, mimicking the LEW phenotype. Examination of potential impacts of glucocorticoids on macrophage function using a human monocyte-derived macrophage cell line (THP-1) showed that cortisol modified phagocytosis in a macrophage phenotype-dependent manner. Overall, our data implicate endogenous glucocorticoids in the regulation of pulmonary macrophage responses to O3.

Glucocorticoids: Fuelling the Fire of Atherosclerosis or Therapeutic Extinguishers?

Glucocorticoids are steroid hormones with key roles in the regulation of many physiological systems including energy homeostasis and immunity. However, chronic glucocorticoid excess, highlighted in Cushing's syndrome, is established as being associated with increased cardiovascular disease (CVD) risk. Atherosclerosis is the major cause of CVD, leading to complications including coronary artery disease, myocardial infarction and heart failure. While the associations between glucocorticoid excess and increased prevalence of these complications are well established, the mechanisms underlying the role of glucocorticoids in development of atheroma are unclear. This review aims to better understand the importance of glucocorticoids in atherosclerosis and to dissect their cell-specific effects on key processes (e.g., contractility, remodelling and lesion development). Clinical and pre-clinical studies have shown both athero-protective and pro-atherogenic responses to glucocorticoids, effects dependent upon their multifactorial actions. Evidence indicates regulation of glucocorticoid bioavailability at the vasculature is complex, with local delivery, pre-receptor metabolism, and receptor expression contributing to responses linked to vascular remodelling and inflammation. Further investigations are required to clarify the mechanisms through which endogenous, local glucocorticoid action and systemic glucocorticoid treatment promote/inhibit atherosclerosis. This will provide greater insights into the potential benefit of glucocorticoid targeted approaches in the treatment of cardiovascular disease.

Hexose-6-phosphate dehydrogenase blockade reverses prostate cancer drug resistance in xenograft models by glucocorticoid inactivation

Prostate cancer resistance to next-generation hormonal treatment with enzalutamide is a major problem and eventuates into disease lethality. Biologically active glucocorticoids that stimulate glucocorticoid receptor (GR) have an 11β-OH moiety, and resistant tumors exhibit loss of 11β-HSD2, the oxidative (11β-OH → 11-keto) enzyme that normally inactivates glucocorticoids, allowing elevated tumor glucocorticoids to drive resistance by stimulating GR. Here, we show that up-regulation of hexose-6-phosphate dehydrogenase (H6PD) protein occurs in prostate cancer tissues of men treated with enzalutamide, human-derived cell lines, and patient-derived prostate tissues treated ex vivo with enzalutamide. Genetically silencing H6PD blocks NADPH generation, which inhibits the usual reductive directionality of 11β-HSD1, to effectively replace 11β-HSD2 function in human-derived cell line models, suppress the concentration of biologically active glucocorticoids in prostate cancer, and reverse enzalutamide resistance in mouse xenograft models. Similarly, pharmacologic blockade of H6PD with rucaparib normalizes tumor glucocorticoid metabolism in human cell lines and reinstates responsiveness to enzalutamide in mouse xenograft models. Our data show that blockade of H6PD, which is essential for glucocorticoid synthesis in humans, normalizes glucocorticoid metabolism and reverses enzalutamide resistance in mouse xenograft models. We credential H6PD as a pharmacologic vulnerability for treatment of next-generation androgen receptor antagonist-resistant prostate cancer by depleting tumor glucocorticoids.

Body Mass Index and Age Effects on Brain 11β-Hydroxysteroid Dehydrogenase Type 1: a Positron Emission Tomography Study

CONTEXT

Cortisol, a glucocorticoid steroid stress hormone, is primarily responsible for stimulating gluconeogenesis in the liver and promoting adipocyte differentiation and maturation. Prolonged excess cortisol leads to visceral adiposity, insulin resistance, hyperglycemia, memory dysfunction, cognitive impairment, and more severe Alzheimer's disease phenotypes. The intracellular enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the conversion of inactive cortisone to active cortisol; yet the amount of 11β-HSD1 in the brain has not been quantified directly in vivo.

OBJECTIVE

We analyzed positron emission tomography (PET) scans with an 11β-HSD1 inhibitor radioligand in twenty-eight individuals (23 M/5F): 10 lean, 13 overweight, and 5 obese individuals. Each individual underwent PET imaging on the high-resolution research tomograph PET scanner after injection of ¹¹C-AS2471907 (n = 17) or ¹⁸F-AS2471907 (n = 11). Injected activity and mass doses were 246 ± 130 MBq and 0.036 ± 0.039 μg, respectively, for ¹¹C-AS2471907, and 92 ± 15 MBq and 0.001 ± 0.001 μg for ¹⁸F-AS2471907. Correlations of mean whole brain and regional distribution volume (V_T) with body mass index (BMI) and age were performed with a linear regression model.

RESULTS

Significant correlations of whole brain mean V_T with BMI and age (V_T = 15.23-0.63 × BMI + 0.27 × Age, p = 0.001) were revealed. Age-adjusted mean whole brain V_T values were significantly lower in obese individuals. Post hoc region specific analyses revealed significantly reduced mean V_T values in the thalamus (lean vs. overweight and lean vs. obese individuals). Caudate, hypothalamus, parietal lobe, and putamen also showed lower V_T value in obese vs. lean individuals. A significant age-associated increase of 2.7 mL/cm³ per decade was seen in BMI-corrected mean whole brain V_T values.

CONCLUSIONS

In vivo PET imaging demonstrated, for the first time, correlation of higher BMI (obesity) with lower levels of the enzyme 11β-HSD1 in the brain and correlation of increased 11β-HSD1 levels in the brain with advancing age.

The 24-hour average concentration of cortisol is elevated in obese African-American youth with type 2 diabetes

INTRODUCTION

24-h average (IC) plasma concentrations of cortisol and growth hormone are lower in obese youth and adults without Type 2 diabetes (T2D) compared to lean subjects. Here we examined IC-cortisol and IC-growth hormone levels in obese youth with and without T2D.

METHODS

We pooled ½-hourly samples from 20 to 24-hour sampling to create an IC for cortisol, cortisone, C-peptide, insulin, growth hormone and cortisol-binding-globulin in obese African-American youth with (n = 8) and without T2D (N = 9). Analytes were assayed by standard methods.

RESULTS

The groups were similar in age and sex, all participants had BMI% ≥94. T2D patients had slightly lower BMI z-score (2.25 ± 0.36 versus 2.58 ± 0.16, p = 0.0429). IC-cortisol (5.70 ± 1.8 μg/dl vs 4.18 ± 1.07 μg/dl, p = 0.0481) was higher and IC-C-peptide (2.33 ± 0.89 ng/ml vs 4.36 ± 1.12 ng/ml, p = 0.001) lower in T2D. There were no differences in cortisone/cortisol or for other analytes between groups. IC-cortisol was correlated with IC-cortisone (r = 0.46, p = 0.0471) but not with ICs of insulin, C-peptide, cortisol-binding-globulin, or growth hormone.

CONCLUSIONS

IC-cortisol levels are higher and IC-C-peptide lower in obese African-American youth with T2D. Higher levels of IC-cortisol in obese youth with T2D may indicate a change in hypothalamic-pituitary-adrenal regulation which may exacerbate hyperglycemia and other metabolic complications of obesity.

Intrauterine growth restriction leads to a high-corticosterone producing offspring: An implication for pulmonary infection susceptibility

AIMS

Although intrauterine growth restriction (IUGR) impairs immune system homeostasis and lung development, its relationship with the susceptibility to pulmonary infections remains unclear. Thus, this study aimed to investigate the impact of IUGR on acute lung inflammatory response induced by bacterial stimulus.

MATERIALS AND METHODS

Pregnant female Wistar rats were subjected to 50% caloric-protein food restriction during gestation. To mimic bacterial lung infection, adult male offspring (12 weeks old) were challenged with a single lipopolysaccharide (LPS) intranasal instillation, and 6 h later, we assessed the acute inflammatory response. Normal birth weight (NBW) animals represent the control group.

KEY FINDINGS

LPS instillation increased the protein levels in the airways of both the NBW and low birth weight (LBW) groups, indicating vascular leakage. LBW animals exhibited a lower number of neutrophils, reduced production of interleukin-6 and macrophage-inflammatory protein-2 and decreased upregulation of intercellular adhesion molecule-1 gene expression in lung tissues. Further analysis revealed that the LBW group produced lower levels of prostaglandin-E₂ and failed to secrete leukotriene-B₄ upon LPS stimulation, which correlated with impaired cyclooxygenase-2 and 5-lipoxygenase expression. These results were probably associated with their inability to upregulate the expression of Toll-like receptor-4 and downstream signaling proteins, such as nuclear factor kappa-B, in the lungs. The LBW group also exhibited abnormal airway thickening and high corticosterone levels under basal conditions.

SIGNIFICANCE

This study suggests that IUGR-induced foetal programming in LBW offspring threatens HPA axis physiology and corticosterone biodisponibility, and impairs the innate response to bacterial antigens, increasing future susceptibility to pulmonary infection.

Roles of Nuclear Receptors in Vascular Calcification

Vascular calcification is defined as an inappropriate accumulation of calcium depots occurring in soft tissues, including the vascular wall. Growing evidence suggests that vascular calcification is an actively regulated process, sharing similar mechanisms with bone formation, implicating both inhibitory and inducible factors, mediated by osteoclast-like and osteoblast-like cells, respectively. This process, which occurs in nearly all the arterial beds and in both the medial and intimal layers, mainly involves vascular smooth muscle cells. In the vascular wall, calcification can have different clinical consequences, depending on the pattern, localization and nature of calcium deposition. Nuclear receptors are transcription factors widely expressed, activated by specific ligands that control the expression of target genes involved in a multitude of pathophysiological processes, including metabolism, cancer, inflammation and cell differentiation. Some of them act as drug targets. In this review we describe and discuss the role of different nuclear receptors in the control of vascular calcification.

The Function of the Hypothalamic-Pituitary-Adrenal Axis During Experimental Autoimmune Encephalomyelitis: Involvement of Oxidative Stress Mediators

Multiple sclerosis (MS) is an inflammatory, demyelinating disease with an unknown origin. Previous studies showed the involvement of the hypothalamic–pituitary–adrenal (HPA) axis to susceptibility to autoimmune diseases, including MS, and its best-characterized animal model, experimental autoimmune encephalomyelitis (EAE). During MS/EAE, innate immune cells are activated and release cytokines and other inflammatory mediators, leading to a vicious cycle of inflammation. In response to inflammation, the activated HPA axis modulates immune responses via glucocorticoid activity. Because the mechanisms involving oxidative stress to the HPA axis are relatively unrevealed, in this study, we investigate the inflammatory and oxidative stress status of HPA axis during EAE. Our results reveal an upregulation of Pomc gene expression, followed by POMC and ACTH protein increase at the peak of the EAE in the pituitary. Also, prostaglandins are well-known contributors of HPA axis activation, which increases during EAE at the periphery. The upregulated Tnf expression in the pituitary during the peak of EAE occurred. This leads to the activation of oxidative pathways, followed by upregulation of inducible NO synthase expression. The reactive oxidant/nitrosative species (ROS/RNS), such as superoxide anion and NO, increase their levels at the onset and peak of the disease in the pituitary and adrenal glands, returning to control levels at the end of EAE. The corticotrophs in the pituitary increased in number and volume at the peak of EAE that coincides with high lipid peroxidation levels. The expression of MC2R in the adrenal glands increases at the peak of EAE, where strong induction of superoxide anion and malondialdehyde (MDA), reduced total glutathione (GSH) content, and catalase activity occurred at the peak and end of EAE compared with controls. The results obtained from this study may help in understanding the mechanisms and possible pharmacological modulation in MS and demonstrate an effect of oxidative stress exposure in the HPA activation during the course of EAE.

Generalized and tissue specific glucocorticoid resistance

Glucocorticoids (GCs) are steroid hormones that influence several physiologic functions and are among the most frequently prescribed drugs worldwide. Resistance to GCs has been observed in the context of the familial generalized GC resistance (Chrousos' syndrome) or tissue specific GC resistance in chronic inflammatory states. In this review, we have summarized the major factors that influence individual glucocorticoid sensitivity/resistance. The fine-tuning of GC action is determined in a tissue-specific fashion that includes the combination of different GC receptor promoters, translation initiation sites, splice isoforms, interacting proteins, post-translational modifications, and alternative mechanisms of signal transduction.

High-throughput rat immunoglobulin G N-glycosylation profiling revealed subclass-specific changes associated with chronic stress

Immunoglobulin G (IgG) glycosylation corresponds well with immune system changes, so it can potentially be used as a biomarker for the consequences of chronic stress such as low-grade inflammation and enhanced immunosenescence in older animals. Here we present a high-throughput glycoproteomic workflow, including IgG enrichment, HILIC glycopeptide purification, and nano-LC-MS analysis of tryptic glycopeptides applied for the analysis of rat IgG. A cohort of 80 animals was exposed to seven stressors in a customized chronic stress protocol with blood and tissue sampling in three timepoints. Young female rats experienced an increase in agalactosylated glycoforms on IgG2a and IgG2c accompanied by a decrease in monogalactosylation. Among old females, increased galactosylation was observed in the IgG2b subclass, pointing to an anti-inflammatory activity of IgG. Additionally, IgG Fc N-glycosylation patterns in Sprague Dawley rats were analyzed, quantified, and reported for the first time. Our findings emphasize age-, sex- and subclass-dependent differences in IgG glycosylation related to chronic stress exposure, confirming the relevance of newly developed methods for further research in glycobiology of rodent immune response. SIGNIFICANCE: In this study, we showed that a high-throughput streamlined methodology based on protein L 96-well monolithic plates for efficient rat IgG immunoaffinity enrichment from blood plasma, paired with appropriate tryptic glycopeptide preparation, HILIC-SPE enrichment, and nano-LC-MS methods was suitable for quick processing of large sample sets. We report a subclass-specific profiling and changes in rat IgG Fc galactosylation and adrenal gland immunohistochemistry of male and female animals exposed to a customized chronic stress protocol.

The rise in expression and activity of 11β-HSD1 in human mesenchymal progenitor cells induces adipogenesis through increased local cortisol synthesis

11β-Hydroxysteroid dehydrogenase 1 (11β-HSD1) plays an important role in pre-receptor glucocorticoid metabolism. This enzyme is expressed in bone, increases with age, and catalyzes the conversion of the inactive glucocorticoid cortisone into the active glucocorticoid cortisol and vice versa. Here we hypothesized that the physiological activity of 11β-HSD1 to produce cortisol in human mesenchymal progenitor cells (hMSC) is principally sufficient to shift the differentiation potential in the direction of adipogenic. We thus investigated differentiating hMSCs and the mesenchymal stem cell line SCP-1 cultured under osteogenic conditions and stimulated with supra-physiological cortisone levels. The release of active cortisol into the medium was monitored and the influence on cell differentiation analyzed. We revealed an increase in 11β-HSD1 expression followed by increased reductive activity of the enzyme, thereby inducing a more adipogenic phenotype of the cell models via cortisol with negative effects on osteogenesis. Through inhibition experiments with the specific inhibitor 10 j, we proved the enzyme specificity for cortisol synthesis and adipogenic differentiation. Increased expression of 11β-HSD1 followed by higher cortisol levels might thus explain bone marrow adiposity followed by reduced bone quality and stability in old age or in situations of supra-physiological glucocorticoid exposure.

Function and Regulation of the Epithelial Na+ Channel ENaC

The Epithelial Na⁺ Channel, ENaC, comprised of 3 subunits (αβγ, or sometimes δβγENaC), plays a critical role in regulating salt and fluid homeostasis in the body. It regulates fluid reabsorption into the blood stream from the kidney to control blood volume and pressure, fluid absorption in the lung to control alveolar fluid clearance at birth and maintenance of normal airway surface liquid throughout life, and fluid absorption in the distal colon and other epithelial tissues. Moreover, recent studies have also revealed a role for sodium movement via ENaC in nonepithelial cells/tissues, such as endothelial cells in blood vessels and neurons. Over the past 25 years, major advances have been made in our understanding of ENaC structure, function, regulation, and role in human disease. These include the recently solved three-dimensional structure of ENaC, ENaC function in various tissues, and mutations in ENaC that cause a hereditary form of hypertension (Liddle syndrome), salt-wasting hypotension (PHA1), or polymorphism in ENaC that contributes to other diseases (such as cystic fibrosis). Moreover, great strides have been made in deciphering the regulation of ENaC by hormones (e.g., the mineralocorticoid aldosterone, glucocorticoids, vasopressin), ions (e.g., Na⁺ ), proteins (e.g., the ubiquitin-protein ligase NEDD4-2, the kinases SGK1, AKT, AMPK, WNKs & mTORC2, and proteases), and posttranslational modifications [e.g., (de)ubiquitylation, glycosylation, phosphorylation, acetylation, palmitoylation]. Characterization of ENaC structure, function, regulation, and role in human disease, including using animal models, are described in this article, with a special emphasis on recent advances in the field. © 2021 American Physiological Society. Compr Physiol 11:1-29, 2021.

Perinatal determinants of neonatal hair glucocorticoid concentrations

Adult hair glucocorticoid concentrations reflect months of hypothalamic-pituitary-adrenal axis activity. However, little is known about the determinants of neonatal hair glucocorticoids. We tested associations between perinatal exposures and neonatal hair glucocorticoids. Cortisol and cortisone were measured by LC-MS/MS in paired maternal and infant hair samples collected within 10 days of birth (n = 49 term, n = 47 preterm), with neonatal samples collected at 6-weeks in n = 54 preterm infants. We demonstrate cortisol accumulation in hair increases with fetal maturity, with hair cortisol being higher in term than preterm born infants after delivery (median 401 vs 106 pg/mg; p < 0.001). In term born infants, neonatal hair cortisol is positively associated with maternal hair cortisol concentration (β = 0.240, p = 0.045) and negatively associated with birthweight z-score (β = -0.340, p = 0.006). Additionally, being born without maternal labour is associated with lower hair cortisol concentrations (β = -0.489, p < 0.001) and a lower ratio of cortisol to cortisone (β = -0.484, p = 0.001). In preterm infants, histological chorioamnionitis is associated with a higher cortisol to cortisone ratio in hair (β = 0.459, p = 0.001). In samples collected 6 weeks after preterm birth, hair cortisol concentration is associated with cortisol hair concentrations measured after birth (β = 0.523, p < 0.001), chorioamnionitis (β = 0.250, p = 0.049) and postnatal exposures including intravenous hydrocortisone therapy (β = 0.343, p < 0.007) and neonatal sepsis (β = 0.290, p = 0.017). In summary, neonatal hair cortisol is associated with birth gestation, maternal hair cortisol concentration and fetal growth. Additionally, exposures at delivery are important determinants of hair cortisol, and should be considered in the design of future research investigating how neonatal hair cortisol relates to prenatal exposures or fetal development.

Modelling Hydrocortisone Pharmacokinetics on a Subcutaneous Pulsatile Infusion Replacement Strategy in Patients with Adrenocortical Insufficiency

In the context of glucocorticoid (GC) therapeutics, recent studies have utilised a subcutaneous hydrocortisone (HC) infusion pump programmed to deliver multiple HC pulses throughout the day, with the purpose of restoring normal circadian and ultradian GC rhythmicity. A key challenge for the advancement of novel HC replacement therapies is the calibration of infusion pumps against cortisol levels measured in blood. However, repeated blood sampling sessions are enormously labour-intensive for both examiners and examinees. These sessions also have a cost, are time consuming and are occasionally unfeasible. To address this, we developed a pharmacokinetic model approximating the values of plasma cortisol levels at any point of the day from a limited number of plasma cortisol measurements. The model was validated using the plasma cortisol profiles of 9 subjects with disrupted endogenous GC synthetic capacity. The model accurately predicted plasma cortisol levels (mean absolute percentage error of 14%) when only four plasma cortisol measurements were provided. Although our model did not predict GC dynamics when HC was administered in a way other than subcutaneously or in individuals whose endogenous capacity to produce GCs is intact, it was found to successfully be used to support clinical trials (or practice) involving subcutaneous HC delivery in patients with reduced endogenous capacity to synthesize GCs.

Impact of cholesterol-pathways on breast cancer development, a metabolic landscape

ApoB-lipoproteins and their components modulate intracellular metabolism and have been associated with the development of neoplastic phenomena, such as proliferation, anchorage-independent growth, epithelial-mesenchymal transition, and cancer invasion. In cancer cells, the modulation of targets that regulate cholesterol metabolism, such as synthesis de novo, endocytosis, and oxidation, are contributing factors to cancer development. While mechanisms associated with sterol regulatory element-binding protein 2 (SREBP-2)/mevalonate, the low-density lipoprotein receptor (LDL-R) and liver X receptor (LXR) have been linked with tumor growth; metabolites derived from cholesterol-oxidation, such as oxysterols and epoxy-cholesterols, also have been described as tumor processes-inducers. From this notion, we perform an analysis of the role of lipoproteins, their association with intracellular cholesterol metabolism, and the impact of these conditions on breast cancer development, mechanisms that can be shared during atherogenesis promoted mainly by LDL. Pathways connecting plasma dyslipidemias in conjunction with the effect of cholesterol-derived metabolites on intracellular mechanisms and cellular plasticity phenomena could provide new approaches to elucidate the triggering factors of carcinogenesis, conditions that could be considered in the development of new therapeutic approaches.

Differential effects of reduced mineralocorticoid receptor activation by unilateral adrenalectomy vs mineralocorticoid antagonist treatment in patients with primary aldosteronism - Implications for depression and anxiety

The mineralocorticoid receptor (MR) and its ligand aldosterone have been found to play a major role in the pathophysiology of depression. Both could be targets of therapeutic interventions. We analyzed laboratory data and questionnaires evaluating anxiety (using GAD-7 questionnaire) and depression (using PHQD questionnaire) of up to 210 patients with primary aldosteronism (PA) (82 females, 54.7 ± 12.0yrs; 128 males, 48.7 ± 12.8yrs) before and one year after initiation of specific treatment of PA by either adrenalectomy (ADX) or treatment with mineralocorticoid receptor antagonists (MRA). After ADX normalization of aldosterone excess was observed. This was associated with a significant reduction of depressive symptoms, but no significant change in GAD-7 score. MRA treatment was accompanied with persistent high aldosterone levels, but led to a significant improvement of anxiety, but no significant changes in PHQD scores. These data suggest different mechanistic pathways for depression and anxiety mediated via the MR. For treatment of depression a reduction of aldosterone levels might be relevant at CNS locations specific for aldosterone, whereas MRA targets MR more broadly, including areas, where cortisol is the main ligand. MRA may be useful in treatment of anxiety related behavior.

Identification, Expression and Evolution of Short-Chain Dehydrogenases/Reductases in Nile Tilapia (Oreochromis niloticus)

The short-chain dehydrogenases/reductases (SDR) superfamily is involved in multiple physiological processes. In this study, genome-wide identification and comprehensive analysis of SDR superfamily were carried out in 29 animal species based on the latest genome databases. Overall, the number of SDR genes in animals increased with whole genome duplication (WGD), suggesting the expansion of SDRs during evolution, especially in 3R-WGD and polyploidization of teleosts. Phylogenetic analysis indicated that vertebrates SDRs were clustered into five categories: classical, extended, undefined, atypical, and complex. Moreover, tandem duplication of hpgd-a, rdh8b and dhrs13 was observed in teleosts analyzed. Additionally, tandem duplications of dhrs11-a, dhrs7a, hsd11b1b, and cbr1-a were observed in all cichlids analyzed, and tandem duplication of rdh10-b was observed in tilapiines. Transcriptome analysis of adult fish revealed that 93 SDRs were expressed in more than one tissue and 5 in one tissue only. Transcriptome analysis of gonads from different developmental stages showed that expression of 17 SDRs were sexually dimorphic with 11 higher in ovary and 6 higher in testis. The sexually dimorphic expressions of these SDRs were confirmed by in situ hybridization (ISH) and qPCR, indicating their possible roles in steroidogenesis and gonadal differentiation. Taken together, the identification and the expression data obtained in this study contribute to a better understanding of SDR superfamily evolution and functions in teleosts.

11β-hydroxysteroid dehydrogenases: A growing multi-tasking family

This review briefly addresses the history of the discovery and elucidation of the three cloned 11β-hydroxysteroid dehydrogenase (11βHSD) enzymes in the human, 11βHSD1, 11βHSD2 and 11βHSD3, an NADP⁺-dependent dehydrogenase also called the 11βHSD1-like dehydrogenase (11βHSD1L), as well as evidence for yet identified 11βHSDs. Attention is devoted to more recently described aspects of this multi-functional family. The importance of 11βHSD substrates other than glucocorticoids including bile acids, 7-keto sterols, neurosteroids, and xenobiotics is discussed, along with examples of pathology when functions of these multi-tasking enzymes are disrupted. 11βHSDs modulate the intracellular concentration of glucocorticoids, thereby regulating the activation of the glucocorticoid and mineralocorticoid receptors, and 7β-27-hydroxycholesterol, an agonist of the retinoid-related orphan receptor gamma (RORγ). Key functions of this nuclear transcription factor include regulation of immune cell differentiation, cytokine production and inflammation at the cell level. 11βHSD1 expression and/or glucocorticoid reductase activity are inappropriately increased with age and in obesity and metabolic syndrome (MetS). Potential causes for disappointing results of the clinical trials of selective inhibitors of 11βHSD1 in the treatment of these disorders are discussed, as well as the potential for more targeted use of inhibitors of 11βHSD1 and 11βHSD2.

Gut feelings about bacterial steroid-17,20-desmolase

Advances in technology are only beginning to reveal the complex interactions between hosts and their resident microbiota that have co-evolved over centuries. In this review, we present compelling evidence that implicates the host-associated microbiome in the generation of 11β-hydroxyandrostenedione, leading to the formation of potent 11-oxy-androgens. Microbial steroid-17,20-desmolase cleaves the side-chain of glucocorticoids (GC), including cortisol (and its derivatives of cortisone, 5α-dihydrocortisol, and also (allo)- 3α, 5α-tetrahydrocortisol, but not 3α-5β-tetrahydrocortisol) and drugs (prednisone and dexamethasone). In addition to side-chain cleavage, we discuss the gut microbiome's robust potential to transform a myriad of steroids, mirroring much of the host's metabolism. We also explore the overlooked role of intestinal steroidogenesis and efflux pumps as a potential route for GC transport into the gut. Lastly, we propose several health implications from microbial steroid-17,20-desmolase function, including aberrant mineralocorticoid, GC, and androgen receptor signaling in colonocytes, immune cells, and prostate cells, which may exacerbate disease states.

Decreased 11β-Hydroxysteroid Dehydrogenase Type 2 Expression in the Kidney May Contribute to Nicotine/Smoking-Induced Blood Pressure Elevation in Mice

[Figure: see text].

Antenatal Dexamethasone Treatment Induces Sex-dependent Upregulation of NTPDase1/CD39 and Ecto-5'-nucleotidase/CD73 in the Rat Fetal Brain

Dexamethasone (DEX) is frequently used to treat women at risk of preterm delivery, but although indispensable for the completion of organ maturation in the fetus, antenatal DEX treatment may exert adverse sex-dimorphic neurodevelopmental effects. Literature findings implicated oxidative stress in adverse effects of DEX treatment. Purinergic signaling is involved in neurodevelopment and controlled by ectonucleotidases, among which in the brain the most abundant are ectonucleoside triphosphate diphosphohydrolase 1 (NTPDase1/CD39) and ecto-5'-nucleotidase (e5'NT/CD73), which jointly dephosphorylate ATP to adenosine. They are also involved in cell adhesion and migration, processes integral to brain development. Upregulation of CD39 and CD73 after DEX treatment was reported in adult rat hippocampus. We investigated the effects of maternal DEX treatment on CD39 and CD73 expression and enzymatic activity in the rat fetal brain of both sexes, in the context of oxidative status of the brain tissue. Fetuses were obtained at embryonic day (ED) 21, from Wistar rat dams treated with 0.5 mg DEX/kg/day, at ED 16, 17, and 18, and brains were processed and used for further analysis. Sex-specific increase in CD39 and CD73 expression and in the corresponding enzyme activities was induced in the brain of antenatally DEX-treated fetuses, more prominently in males. The oxidative stress induction after antenatal DEX treatment was confirmed in both sexes, although showing a slight bias in males. Due to the involvement of purinergic system in crucial neurodevelopmental processes, future investigations are needed to determine the role of these observed changes in the adverse effects of antenatal DEX treatment.

Antifibrotic Effect of a Novel Selective 11β-HSD2 Inhibitor (WZ51) in a rat Model of Myocardial Fibrosis

Myocardial fibrosis (MF) is one of the leading causes of end-stage heart disease. Many studies have confirmed that inflammation caused by aldosterone may play an important role in the process of MF. A selective 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) enzyme inhibitor can reduce the inactivation of cortisol, allowing cortisol to compete for mineralocorticoid receptors. This study investigated the protective effect of a novel selective 11βHSD2 inhibitor (WZ51) on MF and described its underlying mechanism. The administration of WZ51 in rats with MF significantly alleviated myocardial injury, accompanied by a decrease in lactate dehydrogenase and the creatine kinase myocardial band. Furthermore, WZ51 significantly inhibited the development of MF and increased the protein level of 11β-HSD2. The results of this study demonstrate that 11β-HSD2 plays an important pathological role in MF. Thus, WZ51 may be a potential therapeutic agent for the treatment of this condition.

Sexual Dimorphism in Glucocorticoid Stress Response

Chronic stress is encountered in our everyday life and is thought to contribute to a number of diseases. Many of these stress-related disorders display a sex bias. Because glucocorticoid hormones are the main biological mediator of chronic stress, researchers have been interested in understanding the sexual dimorphism in glucocorticoid stress response to better explain the sex bias in stress-related diseases. Although not yet demonstrated for glucocorticoid regulation, sex chromosomes do influence sex-specific biology as soon as conception. Then a transient rise in testosterone start to shape the male brain during the prenatal period differently to the female brain. These organizational effects are completed just before puberty. The cerebral regions implicated in glucocorticoid regulation at rest and after stress are thereby impacted in a sex-specific manner. After puberty, the high levels of all gonadal hormones will interact with glucocorticoid hormones in specific crosstalk through their respective nuclear receptors. In addition, stress occurring early in life, in particular during the prenatal period and in adolescence will prime in the long-term glucocorticoid stress response through epigenetic mechanisms, again in a sex-specific manner. Altogether, various molecular mechanisms explain sex-specific glucocorticoid stress responses that do not exclude important gender effects in humans.

Adipocyte-Mineralocorticoid Receptor Alters Mitochondrial Quality Control Leading to Mitochondrial Dysfunction and Senescence of Visceral Adipose Tissue

Mineralocorticoid receptor (MR) expression is increased in the adipose tissue (AT) of obese patients and animals. We previously demonstrated that adipocyte-MR overexpression in mice (Adipo-MROE mice) is associated with metabolic alterations. Moreover, we showed that MR regulates mitochondrial dysfunction and cellular senescence in the visceral AT of obese db/db mice. Our hypothesis is that adipocyte-MR overactivation triggers mitochondrial dysfunction and cellular senescence, through increased mitochondrial oxidative stress (OS). Using the Adipo-MROE mice with conditional adipocyte-MR expression, we evaluated the specific effects of adipocyte-MR on global and mitochondrial OS, as well as on OS-induced damage. Mitochondrial function was assessed by high throughput respirometry. Molecular mechanisms were probed in AT focusing on mitochondrial quality control and senescence markers. Adipo-MROE mice exhibited increased mitochondrial OS and altered mitochondrial respiration, associated with reduced biogenesis and increased fission. This was associated with OS-induced DNA-damage and AT premature senescence. In conclusion, targeted adipocyte-MR overexpression leads to an imbalance in mitochondrial dynamics and regeneration, to mitochondrial dysfunction and to ageing in visceral AT. These data bring new insights into the MR-dependent AT dysfunction in obesity.

Improved Urinary Cortisol Metabolome in Addison Disease: A Prospective Trial of Dual-Release Hydrocortisone

CONTEXT

Oral once-daily dual-release hydrocortisone (DR-HC) replacement therapy has demonstrated an improved metabolic profile compared to conventional 3-times-daily (TID-HC) therapy among patients with primary adrenal insufficiency. This effect might be related to a more physiological cortisol profile, but also to a modified pattern of cortisol metabolism.

OBJECTIVE

This work aimed to study cortisol metabolism during DR-HC and TID-HC.

DESIGN

A randomized, 12-week, crossover study was conducted.

INTERVENTION AND PARTICIPANTS

DC-HC and same daily dose of TID-HC were administered to patients with primary adrenal insufficiency (n = 50) vs healthy individuals (n = 124) as controls.

MAIN OUTCOME MEASURES

Urinary corticosteroid metabolites were measured by gas chromatography/mass spectrometry at 24-hour urinary collections.

RESULTS

Total cortisol metabolites decreased during DR-HC compared to TID-HC (P < .001) and reached control values (P = .089). During DR-HC, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity measured by tetrahydrocortisol + 5α-tetrahydrocortisol/tetrahydrocortisone ratio was reduced compared to TID-HC (P < .05), but remained increased vs controls (P < .001). 11β-HSD2 activity measured by urinary free cortisone/free cortisol ratio was decreased with TID-HC vs controls (P < .01) but normalized with DR-HC (P = .358). 5α- and 5β-reduced metabolites were decreased with DR-HC compared to TID-HC. Tetrahydrocortisol/5α-tetrahydrocortisol ratio was increased during both treatments, suggesting increased 5β-reductase activity.

CONCLUSIONS

The urinary cortisol metabolome shows striking abnormalities in patients receiving conventional TID-HC replacement therapy, with increased 11β-HSD1 activity that may account for the unfavorable metabolic phenotype in primary adrenal insufficiency. Its change toward normalization with DR-HC may mediate beneficial metabolic effects. The urinary cortisol metabolome may serve as a tool to assess optimal cortisol replacement therapy.

Acute restraint stress does not alter corticosteroid receptors or 11β-hydroxysteroid dehydrogenase gene expression at hypothalamic-pituitary-adrenal axis regulatory sites in captive male white-crowned sparrows (Zonotrichia leucophrys gambelii)

Capture-restraint is often used to investigate the acute hypothalamic-pituitary-adrenal axis (HPA) response to stress in wild and captive animals through the production of glucocorticoids. Although this approach is useful for understanding changes in glucocorticoids, it overlooks potential changes in the complex regulatory systems associated with the glucocorticoid response, including genomic receptors, steroid metabolizing enzymes, carrier proteins, and downstream target proteins (e.g. gonadotropin-inhibitory hormone; GnIH). The present study in captive male white-crowned sparrows (Zonotrichia leucophrys) tests the hypothesis that corticosteroid receptors (mineralocorticoid - MR and glucocorticoid - GR), 11β-hydroxysteroid dehydrogenase 1 (11βHSD1) and 2 (11βHSD2), corticosteroid binding globulin (CBG), and GnIH undergo rapid changes in expression to mediate the glucocorticoid response to acute stress. To determine dynamic changes in gene mRNA expression in the hippocampus, hypothalamus, pituitary gland, and liver, birds were sampled within 3 min of entering the room and after 10, 30, and 60 min of capture restraint stress in a cloth bag. Restraint stress handling increased CBG and decreased GnIH mRNA expression in the liver and hypothalamus, respectively. MR, GR, 11βHSD1, and 11βHSD2 mRNA expression in the brain, pituitary gland, and liver did not change. No correlations were found between gene expression and baseline or stress-induced plasma corticosterone levels. No rapid changes of MR, GR, 11βHSD1, and 11βHSD2 mRNA expression during a standardized acute restraint protocol suggests that tissue level sensitivity may remain constant during acute stressors. However, the observed rise in CBG mRNA expression could act to facilitate transport to target tissues or buffer the rise in circulating glucocorticoids. Further studies on tissue specific sensitivity are warranted.

Mineralocorticoid receptors in the pathogenesis of insulin resistance and related disorders: from basic studies to clinical disease

Aldosterone is a steroid hormone that regulates blood pressure and cardiovascular function by acting on renal and vascular mineralocorticoid receptors (MRs) to promote sodium retention and modulate endothelial function. Indeed, MRs are expressed in endothelial cells, vascular smooth muscle cells, adipocytes, immune cells, skeletal muscle cells, and cardiomyocytes. Excessive aldosterone and associated MR activation impair insulin secretion, insulin metabolic signaling to promote development of diabetes, and the related cardiometabolic syndrome. These adverse effects of aldosterone are mediated, in part, via increased inflammation, oxidative stress, dyslipidemia, and ectopic fat deposition. Therefore, inhibition of MR activation may have a beneficial effect in prevention of impaired insulin metabolic signaling, type 2 diabetes, and cardiometabolic disorders. This review highlights findings from the recent surge in research regarding MR-related cardiometabolic disorders as well as our contemporary understanding of the detrimental effects of excess MR activation on insulin metabolic signaling.

The Effect of High-Intensity Exercise on Changes in Salivary and Serum Cortisol Proportion Dynamics

Typically, salivary cortisol is reported as 5–10% of total cortisol, but the stability of this proportion and the effect of exercise on the 24-h profile is unclear. Therefore, this study investigated the circadian rhythm of the proportion of serum cortisol represented by salivary cortisol, and the impact of acute high-intensity exercise. Recreationally trained males (n = 8, age = 25.7 ± 2.4 years, height = 174.7 ± 7.8 cm, mass = 69.8 ± 12.1 kg) completed two 24-h profiles (rest and exercise conditions) for serum (Q60) and salivary (Q120) cortisol. Exercise consisted of 5 × 30 s sprinting intervals on the cycle ergometer. Cortisol was assessed using commercially available assays. The proportion (Cprop) of serum cortisol (Cser) represented by salivary cortisol (Csal) was calculated as [Cprop = Csal/ Cser × 100]. Multilevel growth models tested for trends across the 24-h profile. The highest relation between Cser and Csal was observed at 08:00 AM (r = 0.90). The average Cprop was 5.95% and demonstrated a circadian profile characterized by a cubic model. Acute exercise did not alter Cser, Csal, or Cprop. Thus, the proportion of Cser represented by Csal changes across a 24-h period and should be accounted for if using salivary cortisol to reflect circadian output of cortisol.

Corticosteroid-binding-globulin (CBG)-deficient mice show high pY216-GSK3β and phosphorylated-Tau levels in the hippocampus

Corticosteroid-binding globulin (CBG) is the specific carrier of circulating glucocorticoids, but evidence suggests that it also plays an active role in modulating tissue glucocorticoid activity. CBG polymorphisms affecting its expression or affinity for glucocorticoids are associated with chronic pain, chronic fatigue, headaches, depression, hypotension, and obesity with an altered hypothalamic pituitary adrenal axis. CBG has been localized in hippocampus of humans and rodents, a brain area where glucocorticoids have an important regulatory role. However, the specific CBG function in the hippocampus is yet to be established. The aim of this study was to investigate the effect of the absence of CBG on hippocampal glucocorticoid levels and determine whether pathways regulated by glucocorticoids would be altered. We used cbg^-/- mice, which display low total-corticosterone and high free-corticosterone blood levels at the nadir of corticosterone secretion (morning) and at rest to evaluate the hippocampus for total- and free-corticosterone levels; 11β-hydroxysteroid dehydrogenase expression and activity; the expression of key proteins involved in glucocorticoid activity and insulin signaling; microtubule-associated protein tau phosphorylation, and neuronal and synaptic function markers. Our results revealed that at the nadir of corticosterone secretion in the resting state the cbg^-/- mouse hippocampus exhibited slightly elevated levels of free-corticosterone, diminished FK506 binding protein 5 expression, increased corticosterone downstream effectors and altered MAPK and PI3K pathway with increased pY216-GSK3β and phosphorylated tau. Taken together, these results indicate that CBG deficiency triggers metabolic imbalance which could lead to damage and long-term neurological pathologies.

Chemoselective and Site-Selective Reductions Catalyzed by a Supramolecular Host and a Pyridine-Borane Cofactor

Supramolecular catalysts emulate the mechanism of enzymes to achieve large rate accelerations and precise selectivity under mild and aqueous conditions. While significant strides have been made in the supramolecular host-promoted synthesis of small molecules, applications of this reactivity to chemoselective and site-selective modification of complex biomolecules remain virtually unexplored. We report here a supramolecular system where coencapsulation of pyridine-borane with a variety of molecules including enones, ketones, aldehydes, oximes, hydrazones, and imines effects efficient reductions under basic aqueous conditions. Upon subjecting unprotected lysine to the host-mediated reductive amination conditions, we observed excellent ε-selectivity, indicating that differential guest binding within the same molecule is possible without sacrificing reactivity. Inspired by the post-translational modification of complex biomolecules by enzymatic systems, we then applied this supramolecular reaction to the site-selective labeling of a single lysine residue in an 11-amino acid peptide chain and human insulin.

Airway exposure to perfluorooctanoate exacerbates airway hyperresponsiveness and downregulates glucocorticoid receptor expression in asthmatic mice

BACKGROUND

Multiple environmental risk factors play a vital role in the pathogenesis of asthma, which contribute to the phenotypic expression of asthma. Perfluorooctanoate (PFOA) is the most common and abundant perfluorocarbon (PFC) in humans, and it has been detected in water and the atmosphere worldwide. Glucocorticoid receptor (GR) is considered to exert a protective effect on asthma and is associated with the sensitivity to glucocorticoids. Dermal or oral exposure to PFOA has been shown to contribute various effects on airway inflammation in individuals with ovalbumin (OVA)-induced asthma. Notably, airway exposure has a critical contribution to the pathogenesis of asthma. However, the effect of airway exposure to PFOA on airway hyperresponsiveness (AHR) in patients with asthma is not currently understood.

METHODS

BALB/c mice were administered OVA to induce asthma. PFOA was then administered intratracheally to OVA-induced mice for seven days. Then we assessed the effect of airway exposure to PFOA on AHR and the regulation of the GR expression in asthmatic mice.

RESULTS

The results showed aggravated AHR and T helper type 2 (Th2) airway inflammation in asthmatic mice. Furthermore, these mice show a substantial decrease in the expression of the GR mRNA and protein.

CONCLUSIONS

These data strongly suggest that acute airway exposure to PFOA leads to Th2-related AHR and decreases GR expression, which may increase the difficulty in the treatment of asthma.

Long-term magnesium supplementation improves glucocorticoid metabolism: A post-hoc analysis of an intervention trial

OBJECTIVE

Increasing magnesium intake might reduce the risk of cardiovascular disease (CVD). Whether potential effects on cortisol contribute to these beneficial effects on cardiovascular health remains unclear. We therefore studied effects of long-term oral magnesium supplementation on glucocorticoid metabolism, specifically on the excretion of urinary cortisol, cortisone and their metabolites, as well as on the ratios reflecting enzymatic activity of 11β-hydroxysteroid dehydrogenases (11β-HSDs) and A-ring reductases.

DESIGN

A post-hoc analysis of a randomized trial with allocation to a magnesium supplement (350 mg/day) or a placebo for 24-week.

PATIENTS

Forty-nine overweight men and women, aged between 45 and 70 years.

MEASUREMENTS

Cortisol, cortisone and their metabolites (tetrahydrocortisol [THF], allo-tetrahydrocortisol [allo-THF] and tetrahydrocortisone [THE]) were measured in 24-h urine samples. Enzymatic activities of 11β-HSD overall and of 11β-HSD type 2 were estimated as the urinary (THF + allo-THF [THFs])/THE and cortisol/cortisone ratios, respectively. A-ring reductase activity was assessed by ratios of THF/allo-THF, allo-THF/cortisol, THF/cortisol and THE/cortisone.

RESULTS

After 24-week, urinary cortisol excretion was decreased in the magnesium group as compared with the placebo group (-32 nmol/24-h, 95% CI: -59; -5 nmol/24-h, p = .021). Ratios of THFs/THE and cortisol/cortisone were decreased following magnesium supplementation by 0.09 (95% CI: 0.02; 0.17, p = .018) and 0.10 (95% CI: 0.03; 0.17, p = .005), respectively. No effects were observed on A-ring reductase activity.

CONCLUSIONS

We observed a beneficial effect of magnesium supplementation towards a lower 24-h urinary cortisol excretion together with an increased activity of 11β-HSD type 2. Our findings may provide another potential mechanism by which increased magnesium intake lowers CVD risk (ClinicalTrials.gov identifier: NCT02235805).

Steroid profiling of glucocorticoids in microdissected mouse brain across development

Corticosterone is produced by the adrenal glands and also produced locally by other organs, such as the brain. Local levels of corticosterone in specific brain regions during development are not known. Here, we microdissected brain tissue and developed a novel liquid chromatography tandem mass spectrometry method (LC-MS/MS) to measure a panel of seven steroids (including 11-deoxycorticosterone (DOC), corticosterone, and 11-dehydrocorticosterone (DHC) in the blood, hippocampus (HPC), cerebral cortex (CC), and hypothalamus (HYP) of mice at postnatal day (PND) 5, 21, and 90. In a second cohort of mice, we measured the expression of three genes that code for steroidogenic enzymes that regulate corticosterone levels (Cyp11b1, Hsd11b1, and Hsd11b2) in the HPC, CC, and HYP. There were region-specific patterns of steroid levels across development, including higher corticosterone levels in the HPC and HYP than in the blood at PND5. In contrast, corticosterone levels were higher in the blood than in all brain regions at PND21 and PND90. Brain corticosterone levels were not positively correlated with blood corticosterone levels, and correlations across brain regions increased with age. Local corticosterone levels were best predicted by local DOC levels at PND5, but by local DHC levels at PND21 and PND90. Transcripts for the three enzymes were detectable in all samples (with highest expression of Hsd11b1) and showed region-specific changes with age. These data demonstrate that individual brain regions fine-tune local levels of corticosterone during early development and that coupling of glucocorticoid levels across regions increases with age.

Associations of Hair Cortisol Concentrations with General and Organ Fat Measures in Childhood

CONTEXT

Stress may lead to an adverse body fat distribution from childhood onwards.

OBJECTIVE

To examine the associations of hair cortisol concentration (HCC) at 6 years with general and organ fat measures, risk of overweight, and nonalcoholic fatty liver disease (NAFLD) at 10 years and to assess whether these were independent of adiposity measures at 6 years.

DESIGN, SETTING AND PARTICIPANTS

HCCs were measured in hair of 6-year-old children (n = 2042) participating in the Generation R Study, a population-based prospective cohort study.

MAIN OUTCOME MEASURES

Body mass index (BMI), fat mass index measured by dual-energy X-ray absorptiometry scan, and visceral fat index, pericardial fat index, liver fat fraction measured by magnetic resonance imaging and risk of overweight and NAFLD were obtained at 10 years.

RESULTS

The associations of higher HCC at 6 years, with higher BMI, fat mass index, and increased risk of overweight at age 10 years are explained by the relationships observed at 6 years. HCCs at 6 years were associated with a higher liver fat fraction (difference 0.11 liver fat fraction standard deviation score; 95% confidence interval [CI] 0.03, 0.18) and a higher risk of NAFLD at 10 years (odds ratio 1.95; 95% CI 1.06, 3.56), independent of fat mass index at 6 years. HCCs were not associated with pericardial or visceral fat indices.

CONCLUSIONS

Higher HCCs at 6 years were associated with higher BMI, fat mass index, liver fat fraction, and higher risks of overweight and NAFLD at 10 years. Only the associations for liver fat fraction and NAFLD were independent of fat mass index at 6 years.

Long-term administration of prednisolone: Effects on the myocardial tissue of healthy beagle dogs

This study aimed to assess the structural and functional effects of long-term hyperglucocorticoidemia on canine myocardium and compare these parameters with histopathological changes. Twelve healthy male beagle dogs were enrolled and assigned to the high-dose prednisolone (P; n=6) and control (C; n=6) groups. The P group was treated with 2 mg/kg of prednisolone BID for 84 days. Clinical parameters were measured using echocardiography and non-invasive systolic blood pressure (SBP) measured before the initiation of synthetic corticosteroids and at 7, 28, 56, and 84 days after the start of medication. For histological evaluation, cardiovascular tissue was harvested from dogs in groups P (at the end of the medication period) and C (scheduled to be euthanized for unrelated reasons). In the P group, clinical changes including thickening of the left ventricular free wall (LVFW) and interventricular septum (IVS), decreased left ventricular (LV) diastolic function, and increased SBP were observed after the start of medication. During histological evaluation, fibrosis was observed in the LVFW and IVS in the P group. Furthermore, decreased glucocorticoid receptor (GCR) levels were observed in the LVFW, right ventricular free wall (RVFW), and IVS and increased mineralocorticoid receptor (MCR) levels were observed in the LVFW and RVFW in the P group compared with those in the C group. In conclusion, fibrosis may cause LV structural and functional abnormalities in dogs with hyperadrenocorticism. Furthermore, GCR downregulation and upregulated MCR might influence the myocardial fibrosis.

Cortisol on Circadian Rhythm and Its Effect on Cardiovascular System

The synthesis and secretion of cortisol are controlled by the hypothalamic–pituitary–adrenal axis. Cortisol exhibits a proper 24-h circadian rhythm that affects the brain, the autonomic nervous system, the heart, and the vasculature that prepares the cardiovascular system for optimal function during these anticipated behavioral cycles. A literature search was conducted using databases such as Google Scholar, PubMed, and Scopus. Relevant search terms included “circadian rhythm and cardiovascular”, “cortisol”, “cortisol and acute coronary syndrome”, “cortisol and arrhythmias”, “cortisol and sudden cardiac death”, “cortisol and stroke”, and “cardioprotective agents”. A total of 120 articles were obtained on the basis of the above search. Lower levels of cortisol were seen at the beginning of sleep, while there was a rise towards the end of sleep, with the highest level reached at the moment the individual wakes up. In the present review, we discuss the role of 11β-hydroxysteroid dehydrogenase (11β-HSD1), which is a novel molecular target of interest for treating metabolic syndrome and type-2 diabetes mellitus. 11β-HSD1 is the major determinant of cortisol excess, and its inhibition alleviates metabolic abnormalities. The present review highlights the role of cortisol, which controls the circadian rhythm, and describes its effect on the cardiovascular system. The review provides a platform for future potential cardioprotective therapeutic agents.