DNA methylation-mediated 11ßHSD2 downregulation drives the increases in angiotensin-converting enzyme and angiotensin II within preeclamptic placentas.

Preeclampsia (PE) is a complex human-specific complication frequently associated with placental pathology. The local renin-angiotensin system (RAS) in the human placenta, which plays a crucial role in regulating placental function, has been extensively documented. Glucocorticoids (GCs) are a class of steroid hormones. PE cases often have abnormalities in GCs levels and placental GCs barrier. Despite extensive speculation, there is currently no robust evidence indicating that GCs regulate placental RAS. This study aims to investigate these potential relationships. Plasma and placental samples were collected from both normal and PE pregnancies. The levels of angiotensin-converting enzyme (ACE), angiotensin II (Ang II), cortisol, and 11ß-hydroxysteroid dehydrogenases (11ßHSD) were analyzed. In PE placentas, cortisol, ACE, and Ang II levels were elevated, while 11ßHSD2 expression was reduced. Interestingly, a positive correlation was observed between ACE and cortisol levels in the placenta. A significant inverse correlation was found between the methylation statuses within the 11ßHSD2 gene promoter and its expression, meanwhile, 11ßHSD2 expression was negatively correlated with cortisol and ACE levels. In vitro experiments using placental trophoblast cells confirmed that active GCs can stimulate ACE transcription and expression through the GR pathway. Furthermore, 11ßHSD2 knockdown could enhance this activating effect. An in vivo study using a rat model of intrauterine GCs overexposure during mid-to-late gestation suggested that excess GCs in utero lead to increased ACE and Ang II levels in the placenta. Collectively, this study provides the first evidence of the relationships between 11ßHSD2 expression, GCs barrier, ACE, and Ang II levels in the placenta. It not only contributes to understanding the pathological features of the placental GCs barrier and RAS under PE conditions, also provides important information for revealing the pathological mechanism of PE.

11ß-Hydroxysteroid dehydrogenase and the brain: Not (yet) lost in translation.

11-beta-hydroxysteroid dehydrogenases (11ß-HSDs) catalyse the conversion of active 11-hydroxy glucocorticoids (cortisol, corticosterone) and their inert 11-keto forms (cortisone, 11-dehydrocorticosterone). They were first reported in the body and brain 70 years ago, but only recently have they become of interest. 11ß-HSD2 is a dehydrogenase, potently inactivating glucocorticoids. In the kidney, 11ß-HSD2 generates the aldosterone-specificity of intrinsically non-selective mineralocorticoid receptors. 11ß-HSD2 also protects the developing foetal brain and body from premature glucocorticoid exposure, which otherwise engenders the programming of neuropsychiatric and cardio-metabolic disease risks. In the adult CNS, 11ß-HSD2 is confined to a part of the brain stem where it generates aldosterone-specific central control of salt appetite and perhaps blood pressure. 11ß-HSD1 is a reductase, amplifying active glucocorticoid levels within brain cells, notably in the cortex, hippocampus and amygdala, paralleling its metabolic functions in peripheral tissues. 11ß-HSD1 is elevated in the ageing rodent and, less certainly, human forebrain. Transgenic models show this rise contributes to age-related cognitive decline, at least in mice. 11ß-HSD1 inhibition robustly improves memory in healthy and pathological ageing rodent models and is showing initial promising results in phase II studies of healthy elderly people. Larger trials are needed to confirm and clarify the magnitude of effect and define target populations. The next decade will be crucial in determining how this tale ends - in new treatments or disappointment.

11ß-Hydroxysteroid dehydrogenase type 2 may mediate the stress-specific effects of cortisol on brain cell proliferation in adult zebrafish (Danio rerio).

Stress-induced increases in cortisol can stimulate or inhibit brain cell proliferation, but the mechanisms behind these opposing effects are unknown. We tested the hypothesis that 11ß-hydroxysteroid dehydrogenase type 2 (Hsd11b2), a glucocorticoid-inactivating enzyme expressed in neurogenic regions of the adult zebrafish brain, mitigates cortisol-induced changes to brain cell proliferation, using one of three stress regimes: a single 1 min air exposure (acute stress), two air exposures spaced 24 h apart (repeat acute stress) or social subordination (chronic stress). Plasma cortisol was significantly elevated 15 min after air exposure and recovered within 24 h after acute and repeat acute stress, whereas subordinate fish exhibited significant and sustained elevations relative to dominant fish for 24 h. Following acute stress, brain hsd11b2 transcript abundance was elevated up to 6 h after a single air exposure but was unchanged by repeat acute stress or social subordination. A sustained increase in brain Hsd11b2 protein levels occurred after acute stress, but not after repeat or chronic stress. Following acute and repeat acute stress, brain pcna transcript abundance (a marker of cell proliferation) exhibited a prolonged elevation, but was unaffected by social subordination. Interestingly, the number of telencephalic BrdU+ cells increased in fish after a single air exposure but was unchanged by repeat acute stress. Following acute and repeat acute stress, fish expressed lower brain glucocorticoid and mineralocorticoid receptor (gr and mr) transcript abundance while subordinate fish exhibited no changes. Taken together, these results demonstrate stressor-specific regulation of Hsd11b2 in the zebrafish brain that could modulate rates of cortisol catabolism contributing to observed differences in brain cell proliferation.

Pseudohyperaldosteronism Due to Licorice: A Practice-Based Learning from a Case Series.

Pseudohyperaldosteronism (PHA) is characterized by hypertension, hypokalemia, and a decrease in plasma renin and aldosterone levels. It can be caused by several causes, but the most frequent is due to excess intake of licorice. The effect is mediated by the active metabolite of licorice, glycyrrhetinic acid (GA), which acts by blocking the 11-hydroxysteroid dehydrogenase type 2 and binding to the mineralocorticoid receptor (MR) as an agonist. The management of licorice-induced PHA depends on several individual factors, such as age, gender, comorbidities, duration and amount of licorice intake, and metabolism. The clinical picture usually reverts upon licorice withdrawal, but sometimes mineralocorticoid-like effects can be critical and persist for several weeks, requiring treatment with MR blockers and potassium supplements. Through this case series of licorice-induced PHA, we aim to increase awareness about exogenous PHA, and the possible risk associated with excess intake of licorice. An accurate history is mandatory in patients with hypertension and hypokalemia to avoid unnecessary testing. GA is a component of several products, such as candies, breath fresheners, beverages, tobacco, cosmetics, and laxatives. In recent years, the mechanisms of action of licorice and its active compounds have been better elucidated, suggesting its benefits in several clinical settings. Nevertheless, licorice should still be consumed with caution, considering that licorice-induced PHA is still an underestimated condition, and its intake should be avoided in patients with increased risk of licorice toxicity due to concomitant comorbidities or interfering drugs.

The Role of microRNA in the Regulation of Cortisol Metabolism in the Adipose Tissue in the Course of Obesity.

The similarity of the clinical picture of metabolic syndrome and hypercortisolemia supports the hypothesis that obesity may be associated with impaired expression of genes related to cortisol action and metabolism in adipose tissue. The expression of genes encoding the glucocorticoid receptor alpha (GR), cortisol metabolizing enzymes (HSD11B1, HSD11B2, H6PDH), and adipokines, as well as selected microRNAs, was measured by real-time PCR in adipose tissue from 75 patients with obesity, 19 patients following metabolic surgery, and 25 normal-weight subjects. Cortisol levels were analyzed by LC-MS/MS in 30 pairs of tissues. The mRNA levels of all genes studied were significantly (p < 0.05) decreased in the visceral adipose tissue (VAT) of patients with obesity and normalized by weight loss. In the subcutaneous adipose tissue (SAT), GR and HSD11B2 were affected by this phenomenon. Negative correlations were observed between the mRNA levels of the investigated genes and selected miRNAs (hsa-miR-142-3p, hsa-miR-561, and hsa-miR-579). However, the observed changes did not translate into differences in tissue cortisol concentrations, although levels of this hormone in the SAT of patients with obesity correlated negatively with mRNA levels for adiponectin. In conclusion, although the expression of genes related to cortisol action and metabolism in adipose tissue is altered in obesity and miRNAs may be involved in this process, these changes do not affect tissue cortisol concentrations.

Phthalates cause a low-renin phenotype commonly found in premature infants with idiopathic neonatal hypertension.

Since the 1970s, when the initial reports of neonatal hypertension related to renal artery thromboembolism were published, other secondary causes of neonatal hypertension have been reported. Those infants with no identifiable cause of hypertension were labeled with a variety of terms. Herein, we describe such infants as having idiopathic neonatal hypertension (INH). Most, but not all, of these hypertensive infants were noted to have bronchopulmonary dysplasia (BPD). More recently, reports described common clinical characteristics seen in INH patients, whether or not they had BPD. This phenotype includes low plasma renin activity, presentation near 40 weeks postmenstrual age, and a favorable response to treatment with spironolactone. A small prospective study in INH patents showed evidence of mineralocorticoid receptor activation due to inhibition of 11ß-HSD2, the enzyme that converts cortisol to the less potent mineralocorticoid-cortisone. Meanwhile, phthalate metabolites have been shown to inhibit 11ß-HSD2 in human microsomes. Premature infants can come in contact with exceptionally large phthalate exposures, especially those infants with BPD. This work describes a common low-renin phenotype, commonly seen in patients categorized as having INH. Further, we review the evidence that hypertension in INH patients with the low-renin phenotype may be mediated by phthalate-associated inhibition of 11ß-HSD2. Lastly, we review the implications of these findings regarding identification, treatment, and prevention of the low-renin hypertension phenotype seen in premature infants categorized as having INH.

Down-Regulation of the Mineralocorticoid Receptor (MR) and Up-Regulation of Hydroxysteroid 11-Beta Dehydrogenase Type 2 (HSD11B2) Isoenzyme in Critically Ill Patients.

Objective: The mineralocorticoid receptor (MR) has two ligands, aldosterone and cortisol. Hydroxysteroid 11-beta dehydrogenase (HSD11B) isoenzymes regulate which ligand will bind to MR. In this study we aimed to evaluate the expression of the MR and the HSD11B isozymes in peripheral polymorphonuclear cells (PMNs) in critical illness for a 13-day period.Design: Prospective studySetting: One multi-disciplinary intensive care unit (ICU)Participants: Forty-two critically ill patientsMethods: Messenger RNA (mRNA) expression of MR, HSD11B1, and HSD11B2, aldosterone levels, and plasma renin activity (PRA) were measured in 42 patients on ICU admission and on days 4, 8, and 13. Twenty-five age and sex-matched healthy subjects were used as controls.Results: Compared to healthy controls, MR expression in critically ill patients was lower during the entire study period. HSD11B1 expression was also lower, while HSD11B2 expression was higher. In patients, PRA, aldosterone, the aldosterone:renin ratio, and cortisol remained unaltered during the study period.Conclusion: Our results suggest that, in our cohort of critically ill patients, local endogenous cortisol availability is diminished, pointing towards glucocorticoid resistance. Aldosterone probably occupies the MR, raising the possibility that PMNs might be useful to study to gain insights into MR functionality during pathological states.

Comparative study on the gene expression of corticosterone metabolic enzymes in embryonic tissues between Tibetan and broiler chickens.

Glucocorticoids (GCs) are an essential mediator hormone that can regulate animal growth, behavior, the phenotype of offspring, and so on, while GCs in poultry are predominantly corticosterones. The biological activity of GCs is mainly regulated by the intracellular metabolic enzymes, including 11ß-hydroxysteroid dehydrogenases 1 (11ß-HSD1), 11ß-hydroxysteroid dehydrogenases 2 (11ß-HSD2), and 20-hydroxysteroid dehydrogenase (20-HSD). To investigate the embryonic mechanisms of phenotypic differences between breeds, we compared the expression of corticosterone metabolic enzyme genes in the yolk-sac membrane and chorioallantoic membrane (CAM). We described the tissue distribution and ontogenic patterns of corticosterone metabolic enzymes during embryonic incubation between Tibetan and broiler chickens. Forty fertilized eggs from Tibetan and broiler chickens were incubated under hypoxic and normoxic conditions, respectively. Real-time fluorescence quantitative PCR was used to examine the expression of 11ß-HSD1/2, and 20-HSD mRNA in embryonic tissues. The results showed that the expression levels of yolk-sac membrane mRNA of 11ß-HSD2 and 20-HSD in Tibetan chickens on E14 (embryonic day of 14) were significantly lower than those of broiler chickens (P < 0.05), and these genes expression of CAM in Tibetan chickens were higher than those of broiler chickens (P < 0.05). In addition, the three genes in the yolk-sac membrane and CAM were followed by a down-regulation on E18 (embryonic day of 18). The 11ß-HSD1 and 11ß-HSD2 genes followed a similar tissue-specific pattern: the expression level was more abundantly in the liver, kidney, and intestine, with relatively lower abundance in the hypothalamus and muscle, and the expression level of 20-HSD genes in all tissues tested was higher. In the liver, 20-HSD of both Tibetan and broiler chickens showed different ontogeny development patterns, and hepatic mRNA expression of 20-HSD in broiler chickens was significantly higher than that of Tibetan chickens of the same age from E14 to E18 (P < 0.05). This study preliminarily revealed the expression levels of cortisol metabolic genes in different tissues during the development process of Tibetan and broiler chicken embryos. It provided essential information for in-depth research of the internal mechanism of maternal GCs programming on offspring.

Direct inhibition of bisphenols on human and rat 11ß-hydroxysteroid dehydrogenase 2: Structure-activity relationship and docking analysis.

Bisphenols (BPs) as endocrine-disrupting compounds have drawn attention to their health hazards. Whether a BP interferes with glucocorticoid metabolism remains unclear. 11ß-Hydroxysteroid dehydrogenase 2 (11ß-HSD2) is a key glucocorticoid-metabolizing enzyme that controls fetal glucocorticoid levels across the placental barrier and mineralocorticoid receptor specificity in the kidney. In this study, 11 BPs were tested to inhibit human placental and rat renal 11ß-HSD2 and were analyzed for inhibitory potency, mode action, and docking parameters. BPs had inhibitory potency against human 11ß-HSD2: BPFL>BPAP>BPZ>BPB>BPC>BPAF>BPA>TDP and the IC10 values were 0.21, 0.55, 1.04, 2.04, 2.43, 2.57, 14.43, and 22.18 µM, respectively. All BPs are mixed inhibitors except BPAP, which is a competitive inhibitor for human 11ß-HSD2. Some BPs also inhibited rat renal 11ß-HSD2, with BPB (IC50, 27.74 ± 0.95) > BPZ (42.14 ± 0.59) > BPAF (54.87 ± 1.73) > BPA (77.32 ± 1.20) > other BPs (about 100 µM). Docking analysis showed that all BPs bound to the steroid-binding site, interacting with the catalytic residue Tyr232 of both enzymes and the most potent human 11ß-HSD2 inhibitor BPFL acts possibly due to its large fluorene ring that has hydrophobic interaction with residues Glu172 and Val270 and π-stacking interaction with catalytic residue Tyr232. The increase in the size of substituted alkanes and halogenated groups in the methane moiety of the bridge of BPs increases its inhibitory potency. Regressions of the lowest binding energy with inhibition constant indicated that there was an inverse regression. These results indicated that BPs significantly inhibited human and rat 11ß-HSD2 activity and that there were species-dependent differences.

Cadmium induces placental glucocorticoid barrier damage by suppressing the cAMP/PKA/Sp1 pathway and the protective role of taurine.

Cadmium (Cd) exposure during pregnancy damages the placental glucocorticoid (GC) barrier, exposes the foetus to excess corticosterone (CORT) levels, and eventually inhibits foetal development. In addition, taurine (Tau) alleviates the toxicity of Cd on liver and kidney, but limited data are available on the role of Tau against the toxicity of heavy metals on female reproduction and fetal development. The present study was conducted to investigate the specific mechanism of Cd-induced placental GC barrier damage and the protective role of Tau. Pregnant rats were administered CdCl2 (1 mg/kg/day) and Tau (100, 200, or 300 mg/kg/day) by gavage from gestational day (GD) 0 to 19. The data showed that CdCl2 increased the foetal growth restriction (FGR) rate of the offspring, and the levels of CORT in the placental, maternal and foetal serum. Treatment with Tau significantly reversed the impact of Cd on both maternal and fetal parameters. Additionally, Tau can attenuate Cd-induced inhibition of 11ß-hydroxysteroid dehydrogenase 2 (11ß-HSD2) and specificity protein 1 (Sp1) in vivo and vitro. Furthermore, Sp1-siRNA alone reduced 11ß-HSD2 levels and had a further inhibitory effect when the cells were treated with Cd simultaneously. Moreover, Cd suppressed cAMP/PKA signalling. Forskolin (adenylate cyclase agonist) pretreatment activated cAMP/PKA signalling and restored the Cd-induced downregulation of Sp1 and 11ß-HSD2. Tau alleviated the Cd-induced decrease of Sp1 via activating cAMP/PKA signalling. Therefore, the results highlight that Tau protects against Cd-induced impairments in GC barrier damage by upregulating the cAMP/PKA/Sp1 pathway in placental trophoblasts.

Long noncoding RNA PVT1 accelerates the growth of placental trophoblasts in preeclampsia through the microRNA-24-3p/HSD11B2 axis.

Long noncoding RNA plasmacytoma variant translocation 1 (PVT1) is essential for the maintenance of normal functions of trophoblasts in preeclampsia (PE). This study aims to decipher the concrete mechanism of PVT1 with the microRNA-24-3p/Type-2 11ß-hydroxysteroid dehydrogenase (miR-24-3p/HSD11B2) axis in PE. PVT1, miR-24-3p, and HSD11B2 expression levels in normal placental tissues and PE placental tissues were defined. HTR-8/SVneo cells were transfected to determine the effects of PVT1, miR-24-3p, and HSD11B2 on the growth of HTR-8/SVneo cells. The relationships among PVT1/miR-24-3p/HSD11B2 in HTR-8/SVneo cells were identified. PVT1 and HSD11B2 were downregulated, while miR-24-3p was upregulated in the placenta of PE. Upregulated/downregulated PVT1 promoted/impeded the growth of human placental trophoblast (HTR-8/SVneo) cells in PE. Restored/knocked down miR-24-3p impeded/enhanced the growth of HTR-8/SVneo cells in PE. PVT1 inhibited miR-24-3p to mediate HSD11B2. PVT1 sponges miR-24-3p to regulate HSD11B2; thereby, the growth of placental trophoblasts is promoted in PE.

11ß-Hydroxysteroid dehydrogenase 2: A key mediator of high susceptibility to osteoporosis in offspring after prenatal dexamethasone exposure.

Epidemiological investigations have shown that individuals treated with dexamethasone during pregnancy have an increased risk of osteoporosis after birth. Our studies reported that peak bone mass was decreased in the prenatal dexamethasone exposure (PDE) offspring before chronic stress, while further decrease was observed after chronic stress. Simultaneously, increase of bone local active corticosterone was observed in the PDE offspring, while further increase was also observed after chronic stress. Moreover, the histone H3 lysine 9 acetylation (H3K9ac) level of 11-beta hydroxysteroid dehydrogenase 2 (11ß-HSD2) and its expression in bone tissue of PDE offspring rats remained lower than the control before and after birth. Injection of 11ß-HSD2 overexpression lentivirus into the bone marrow cavity could partially alleviate the accumulation of bone local active corticosterone and bone loss induced by PDE. In vitro, dexamethasone inhibited the expression of 11ß-HSD2 and aggravated the inhibitory effect of corticosterone on the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Overexpression of 11ß-HSD2 partially alleviated the inhibitory effect of corticosterone. Moreover, dexamethasone promoted the nuclear translocation of glucocorticoid receptor (GR), which resulted in the stimulation of 11ß-HSD2 expression due to the binding of GR to the 11ß-HSD2 promoter region directly, as well as increasing H3K9ac level in the 11ß-HSD2 promoter region by recruiting histone deacetylase 11 (HDAC11). Our results indicated that low expression of 11ß-HSD2 in bone tissue is an important mediator for the high susceptibility to osteoporosis in PDE adult offspring.

Selenium attenuates the cadmium-induced placenta glucocorticoid barrier damage by up-regulating the expression of specificity protein 1.

Cadmium (Cd) is an environmental pollutant and pregnant women are especially susceptible to the effects of exposure to Cd. Our previous study found Cd can be accumulated in the placenta and causes fetal growth restriction (FGR) through damage the placental glucocorticoid barrier. Selenium (Se), as an essential micronutrient, can allivate Cd-induced toxicity. In this study, we aim to explore the protective mechanism of Se against Cd-induced the placental glucocorticoid barrier damage and FGR. Pregnant Sprague Dawley (SD) rats were exposed to CdCl2 (1 mg/kg/day) and Na2 SeO3 (0.1-0.2-0.3 mg/kg/day) by gavage from gestational day (GD) 0 to GD 19. The results showed that reduced fetal weight, increased corticosterone concentrations in the maternal and fetal serum, and impaired placental labyrinth layer blood vessel development, appeared in pregnant rats after Cd exposure and improved after treated with Se. In cell experiments, we confirmed that Se reduces Cd-induced apoptosis. Moreover, Se can abolish Cd-induced 11ß-HSD2 and specificity protein 1 (Sp1) decreasing in vivo and vitro. In human JEG-3 cells, the knockdown of Sp1 expression by small interfering RNA can suppressed the protective effect of Se on Cd-induced 11ß-HSD2 decreasing. In general, our results demonstrated that Se is resistant to Cd-induced FGR through upregulating the placenta barrier via activation of the transcription factor Sp1.

Intrauterine programming of cartilaginous 11ß-HSD2 induced by corticosterone and caffeine mediated susceptibility to adult osteoarthritis.

Our previous study reported that prenatal caffeine exposure (PCE) could induce chondrodysplasia and increase the susceptibility to osteoarthritis in offspring rats. However, the potential mechanisms and initiating factors remain unknown. This study aims to investigate whether 11ß-HSD2, a glucocorticoid-metabolizing enzyme, is involved in the susceptibility of osteoarthritis induced by PCE and to further explore its potential mechanisms and initiating factors. Firstly, we found that PCE reduced cartilage matrix synthesis (aggrecan/Col2a1 expression) in male adult offspring rats and exhibited an osteoarthritis phenotype following chronic stress, which was associated with persistently reduced H3K9ac and H3K27ac levels at the promoter of 11ß-HSD2 as well as its expression in the cartilage from fetus to adulthood. The expression of 11ß-HSD2, aggrecan and Col2a1 were all decreased by corticosterone in the fetal chondrocytes, while overexpression of 11ß-HSD2 could partially alleviate the decrease of matrix synthesis induced by corticosterone in vitro. Furthermore, the glucocorticoid receptor (GR) activated by glucocorticoids directly bonded to the promoter region of 11ß-HSD2 to inhibit its expression. Meanwhile, the activated GR reduced the H3K9ac and H3K27ac levels of 11ß-HSD2 by recruiting HDAC4 and promoting GR-HDAC4 protein interaction to inhibit the 11ß-HSD2 expression. Moreover, caffeine could reduce the expression of 11ß-HSD2 by inhibiting the cAMP/PKA signaling pathway but without reducing the H3K9ac and H3K27ac levels of 11ß-HSD2, thereby synergistically enhancing the corticosterone effect. In conclusion, the persistently reduced H3K9ac and H3K27ac levels of 11ß-HSD2 from fetus to adulthood mediated the inhibition of cartilage matrix synthesis and the increased susceptibility to osteoarthritis. This epigenetic programming change in utero was induced by glucocorticoids with synergistic effect of caffeine.

Abnormal neonatal sodium handling in skin precedes hypertension in the SAME rat.

We discovered high Na+ and water content in the skin of newborn Sprague-Dawley rats, which reduced ~ 2.5-fold by 7 days of age, indicating rapid changes in extracellular volume (ECV). Equivalent changes in ECV post birth were also observed in C57Bl/6 J mice, with a fourfold reduction over 7 days, to approximately adult levels. This established the generality of increased ECV at birth. We investigated early sodium and water handling in neonates from a second rat strain, Fischer, and an Hsd11b2-knockout rat modelling the syndrome of apparent mineralocorticoid excess (SAME). Despite Hsd11b2-/- animals exhibiting lower skin Na+ and water levels than controls at birth, they retained ~ 30% higher Na+ content in their pelts at the expense of K+ thereafter. Hsd11b2-/- neonates exhibited incipient hypokalaemia from 15 days of age and became increasingly polydipsic and polyuric from weaning. As with adults, they excreted a high proportion of ingested Na+ through the kidney, (56.15 ± 8.21% versus control 34.15 ± 8.23%; n = 4; P < 0.0001), suggesting that changes in nephron electrolyte transporters identified in adults, by RNA-seq analysis, occur by 4 weeks of age. Our data reveal that Na+ imbalance in the Hsd11b2-/- neonate leads to excess Na+ storage in skin and incipient hypokalaemia, which, together with increased, glucocorticoid-induced Na+ uptake in the kidney, then contribute to progressive, volume contracted, salt-sensitive hypertension. Skin Na+ plays an important role in the development of SAME but, equally, may play a key physiological role at birth, supporting post-natal growth, as an innate barrier to infection or as a rudimentary kidney.

Species-specific differences in the inhibition of 11ß-hydroxysteroid dehydrogenase 2 by itraconazole and posaconazole.

11ß-hydroxysteroid dehydrogenase 2 (11ß-HSD2) converts active 11ß-hydroxyglucocorticoids to their inactive 11-keto forms, thereby preventing inappropriate mineralocorticoid receptor activation by glucocorticoids. Disruption of 11ß-HSD2 activity by genetic defects or inhibitors causes the syndrome of apparent mineralocorticoid excess (AME), characterized by hypokalemia, hypernatremia and hypertension. Recently, the azole antifungals itraconazole and posaconazole were identified to potently inhibit human 11ß-HSD2, and several case studies described patients with acquired AME. To begin to understand why this adverse drug effect was missed during preclinical investigations, the inhibitory potential of itraconazole, its main metabolite hydroxyitraconazole (OHI) and posaconazole against 11ß-HSD2 from human and three commonly used experimental animals was assessed. Whilst human 11ß-HSD2 was potently inhibited by all three compounds (IC50 values in the nanomolar range), the rat enzyme was moderately inhibited (1.5- to 6-fold higher IC50 values compared to human), and mouse and zebrafish 11ß-HSD2 were very weakly inhibited (IC50 values above 7 µM). Sequence alignment and application of newly generated homology models for human and mouse 11ß-HSD2 revealed significant differences in the C-terminal region and the substrate binding pocket. Exchange of the C-terminus and substitution of residues Leu170,Ile172 in mouse 11ß-HSD2 by the corresponding residues His170,Glu172 of the human enzyme resulted in a gain of sensitivity to itraconazole and posaconazole, resembling human 11ß-HSD2. The results provide an explanation for the observed species-specific 11ß-HSD2 inhibition by the studied azole antifungals. The obtained structure-activity relationship information should facilitate future assessments of 11ß-HSD2 inhibitors and aid choosing adequate animal models for efficacy and safety studies.

Contribution of placental 11ß-HSD2 to the pathogenesis of preeclampsia.

Preeclampsia, a major human pregnancy-specific disorder, leads to maternal and fetal morbidity and mortality. Here we reported that 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2), an enzyme that degrades active glucocorticoids, is one of the key factors that contributes to preeclampsia development. In the pregnant rat model, we firstly confirmed that administration of 11ß-HSD2 inhibitor carbenoxolone (CBX) subcutaneously or by placenta-targeted delivery system could lead to a decrease in placental 11ß-HSD2 expression and activity and an increase in corticosterone level in placenta and maternal circulation. Then, we showed that subcutaneous administration and placenta-targeted delivery of CBX resulted in the hallmark of preeclampsia-like features including hypertension, proteinuria, renal damages as well as elevated circulatory soluble fms-like tyrosine kinase 1 (sFlt1) and increased sFlt1/placental growth factor (PlGF) ratio in pregnant rats. These animals displayed decreased trophoblast invasion in uterus, impaired spiral artery remodeling, and reduced placental blood flow. Preeclampsia-like features could also be induced by administration of dexamethasone in pregnant rats. In the cultured human trophoblast models, we found that cortisol only inhibited migration and invasion of the extravillous trophoblasts with 11ß-HSD2 knockdown, and promoted sFlt1 release in the cultured syncytiotrophoblasts with 11ß-HSD2 knockdown. Furthermore, we elucidated that cortisol stimulated a disintegrin and metalloprotease (ADAM)17 expression in placentas, thereby promoting sFlt1 release in placenta. Collectively, our study provided the evidence that placental 11ß-HSD2 dysfunction plays a key role in the development of preeclampsia and immediately identified innovative target to counteract preeclampsia.

Sex difference in adrenal developmental toxicity induced by dexamethasone and its intrauterine programming mechanism.

Dexamethasone is widely used to treat preterm labor and related diseases. However, prenatal dexamethasone treatment (PDT) can cause multiorgan developmental toxicities in offspring. Our previous study found that the occurrence of fetal-originated diseases was associated with adrenal developmental programming alterations in offspring. Here, we investigated the effects of PDT on adrenal function in offspring and its intrauterine programming mechanism. A rat model of PDT was established to observe the alterations of adrenal steroidogenesis in offspring. Furthermore, we confirmed the sex differences of adrenal steroidogenesis and its molecular mechanism combined with in vivo and in vitro experiments. PDT caused a decrease in adrenal steroidogenic function in fetal rats, but it was decreased in males and increased in females after birth. Meanwhile, the adrenal H3K14ac level and expression of 11ß-hydroxysteroid dehydrogenase 2 (11ß-HSD2) in PDT offspring were decreased in males and increased in females, suggesting that 11ß-HSD2 might mediate sex differences in adrenal function. We further confirmed that dexamethasone inhibited the H3K14ac level and expression of 11ß-HSD2 through the GR/SP1/p300 pathway. After bilateral testectomy or ovariectomy of adult PDT offspring rats, adrenal 11ß-HSD2 expression and steroidogenic function were both reduced. Using rat primary fetal adrenal cells, the differential expression of AR and ERß was proven to be involved in regulating the sex difference in 11ß-HSD2 expression. This study demonstrated the sex difference in adrenal steroidogenic function of PDT offspring after birth and elucidated a sex hormone receptor-dependent epigenetically regulating mechanism for adrenal 11ß-HSD2 programming alteration.

A life-threatening case of pseudo-aldosteronism secondary to excessive liquorice ingestion.

BACKGROUND: Liquorice is found in many food products, soft drinks, and herbal medicines. Liquorice ingestion is an uncommon cause of apparent mineralocorticoid excess or pseudo-aldosteronism. The mechanism involves the inhibition of 11-beta-hydroxysteroid dehydrogenase type-2 by the active ingredient called glycyrrhizin. This leads to the uninhibited activation of mineralocorticoid receptors by cortisol. Confectionary products that contain liquorice are readily available in many countries around the world. CASE PRESENTATION: We report a case of severe refractory hypokalaemia with hypertensive crisis and acute pulmonary oedema due to excessive liquorice consumption. A 79-year-old female presented to the emergency department following a road traffic accident. She described feeling weak and dizzy while driving before the collision. She attended her general practitioner (GP) several weeks earlier for fatigue and was being managed for hypokalaemia on oral potassium supplements. Investigations revealed hypertension (BP 180/69 mmHg), severe hypokalaemia (K 2.2 mmol/l), normal renal function, normal serum magnesium with metabolic alkalosis. Spot urinary potassium was 22 mmol/l. The patient denied taking medications including over-the-counter or herbal medication that can cause hypokalaemia. Hypokalaemia persisted despite aggressive intravenous (i.v.) and oral potassium replacement. She later developed a hypertensive crisis (BP 239/114 mmHg) with pulmonary oedema. She required admission to the intensive care unit and was managed with intravenous furosemide infusion and isosorbide dinitrate infusion. On further discussion, our patient admitted to struggling with nicotine cravings since quitting smoking two months earlier. She began eating an excessive amount of liquorice sweets to manage her cravings. Suppression of plasma renin and aldosterone supported the diagnosis of apparent mineralocorticoid excess secondary to excessive liquorice consumption. Her symptoms and hypokalaemia resolved after stopping liquorice intake. CONCLUSIONS: This case highlights the life-threatening and refractory nature of hypokalaemia secondary to excessive liquorice consumption. This case also emphasizes the importance of comprehensive history taking including dietary habits. Increased awareness among the public is required regarding the potential health hazards of excessive liquorice consumption.

Pharmacokinetics-based identification of pseudoaldosterogenic compounds originating from Glycyrrhiza uralensis roots (Gancao) after dosing LianhuaQingwen capsule.

LianhuaQingwen capsule, prepared from an herbal combination, is officially recommended as treatment for COVID-19 in China. Of the serial pharmacokinetic investigations we designed to facilitate identifying LianhuaQingwen compounds that are likely to be therapeutically important, the current investigation focused on the component Glycyrrhiza uralensis roots (Gancao). Besides its function in COVID-19 treatment, Gancao is able to induce pseudoaldosteronism by inhibiting renal 11ß-HSD2. Systemic and colon-luminal exposure to Gancao compounds were characterized in volunteers receiving LianhuaQingwen and by in vitro metabolism studies. Access of Gancao compounds to 11ß-HSD2 was characterized using human/rat, in vitro transport, and plasma protein binding studies, while 11ß-HSD2 inhibition was assessed using human kidney microsomes. LianhuaQingwen contained a total of 41 Gancao constituents (0.01-8.56 µmol/day). Although glycyrrhizin (1), licorice saponin G2 (2), and liquiritin/liquiritin apioside (21/22) were the major Gancao constituents in LianhuaQingwen, their poor intestinal absorption and access to colonic microbiota resulted in significant levels of their respective deglycosylated metabolites glycyrrhetic acid (8), 24-hydroxyglycyrrhetic acid (M2D; a new Gancao metabolite), and liquiritigenin (27) in human plasma and feces after dosing. These circulating metabolites were glucuronized/sulfated in the liver and then excreted into bile. Hepatic oxidation of 8 also yielded M2D. Circulating 8 and M2D, having good membrane permeability, could access (via passive tubular reabsorption) and inhibit renal 11ß-HSD2. Collectively, 1 and 2 were metabolically activated to the pseudoaldosterogenic compounds 8 and M2D. This investigation, together with such investigations of other components, has implications for precisely defining therapeutic benefit of LianhuaQingwen and conditions for its safe use.