Efficacy and safety of osilodrostat in patients with Cushing's disease (LINC 3): a multicentre phase III study with a double-blind, randomised withdrawal phase.

BACKGROUND: Cushing's disease is a rare endocrine disorder characterised by cortisol overproduction with severe complications. Therapies for cortisol reduction are often necessary. Here we report the outcomes from the pivotal phase III study of osilodrostat (a potent oral inhibitor of cytochrome P450 11B1, mitochondrial [11ß-hydroxylase]; Novartis Pharma AG, Basel, Switzerland) in patients with Cushing's disease. METHODS: LINC 3 was a prospective, multicentre, open-label, phase III study with a double-blind randomised withdrawal period, that comprised four periods. Patients aged 18-75 years, with confirmed persistent or recurrent Cushing's disease (defined as mean 24-h urinary free cortisol [UFC] concentration >1·5 times the upper limit of normal [ULN] and morning plasma adrenocorticotropic hormone above the lower limit of normal) who had previously had pituitary surgery or irradiation, or were newly diagnosed and who refused surgery or were not surgical candidates, were recruited from 66 hospital sites and private clinical practices in 19 countries. In period 1, open-label osilodrostat was initiated in all participants and adjusted every 2 weeks (1-30 mg twice daily; film-coated tablets for oral administration) on the basis of mean 24-h UFC concentration and safety until week 12. In period 2, weeks 13-24, osilodrostat was continued at the therapeutic dose determined during period 1. In period 3, beginning at week 26, participants who had a mean 24-h UFC concentration of less than or equal to the ULN at week 24, without up-titration after week 12, were randomly assigned (1:1), via an interactive-response technology, stratified by osilodrostat dose at week 24 and history of pituitary irradiation, to continue osilodrostat or switch to placebo for 8 weeks. Participants and investigators were masked to treatment assignment. Ineligible participants continued open-label osilodrostat. In period 4, weeks 35-48, all participants were given open-label osilodrostat until core-study end. The primary objective was to compare the efficacy of osilodrostat versus placebo at the end of period 3. The primary endpoint was the proportion of participants who had been randomly assigned to treatment or placebo with a complete response (ie, mean 24-h UFC concentration of ≤ULN) at the end of the randomised withdrawal period (week 34), without up-titration during this period. The key secondary endpoint was the proportion of participants with a complete response at the end of the single-arm, open-label period (ie, period 2, week 24) without up-titration during weeks 13-24. Analysis was by intention-to-treat for all patients who received at least one dose of osilodrostat (full analysis set; key secondary endpoint) or randomised treatment (randomised analysis set; primary endpoint) and safety was assessed in all enrolled patients who received at least one dose of osilodrostat and had at least one post-baseline safety assessment. LINC 3 is registered with ClinicalTrials.gov, NCT02180217, and is now complete. FINDINGS: Between Nov 12, 2014, and March 22, 2017, 202 patients were screened and 137 were enrolled. The median age was 40·0 years (31·0-49·0) and 106 (77%) participants were female. 72 (53%) participants were eligible for randomisation during the withdrawal phase, of whom 36 were assigned to continue osilodrostat and 35 were assigned to placebo; one patient was not randomly assigned due to investigator decision and continued open-label osilodrostat. More patients maintained a complete response with osilodrostat versus with placebo at week 34 (31 [86%] vs ten [29%]; odds ratio 13·7 [95% CI 3·7-53·4]; p<0·0001). At week 24, 72 (53%; 95% CI 43·9-61·1) of 137 patients maintained a complete response without up-titration after week 12. Most common adverse events (ie, occurred in >25% of participants) were nausea (57 [42%]), headache (46 [34%]), fatigue (39 [28%]), and adrenal insufficiency (38 [28%]). Hypocortisolism occurred in 70 (51%) patients and adverse events related to adrenal hormone precursors occurred in 58 (42%) patients. One patient died, unrelated to study drug, after the core study phase. INTERPRETATION: Twice-daily osilodrostat rapidly reduced mean 24-h UFC and sustained this reduction alongside improvements in clinical signs of hypercortisolism; it was also generally well tolerated. Osilodrostat is an effective new treatment option that is approved in Europe for the treatment of endogenous Cushing's syndrome and in the USA for Cushing's disease. FUNDING: Novartis Pharma AG.

Radiotherapy as a tool for the treatment of Cushing's disease.

Treatment of Cushing's disease (CD) is one of the most challenging tasks in endocrinology. The first-line treatment, transsphenoidal pituitary surgery, is associated with a high failure rate and a high prevalence of recurrence. Re-operation is associated with an even higher rate of a failure and recurrence. There are three main second-line treatments for CD - pituitary radiation therapy (RT), bilateral adrenalectomy and chronic cortisol-lowering medical treatment. All these treatments have their limitations. While bilateral adrenalectomy provides permanent cure of the hypercortisolism in all patients, the unavoidable chronic adrenal insufficiency and the risk of development of Nelson syndrome are of concern. Chronic cortisol-lowering medical treatment is not efficient in all patients and side effects are often a limiting factor. RT is efficient for approximately two-thirds of all patients with CD. However, the high prevalence of pituitary insufficiency is of concern as well as potential optic nerve damage, development of cerebrovascular disease and secondary brain tumours. Thus, when it comes to decide appropriate treatment for patients with CD, who have either failed to achieve remission with pituitary surgery, or patients with recurrence, the pros and cons of all second-line treatment options must be considered.

MANAGEMENT OF ENDOCRINE DISEASE: Management of Cushing's syndrome during pregnancy: solved and unsolved questions.

With fewer than 200 reported cases, Cushing's syndrome (CS) in pregnancy remains a diagnostic and therapeutic challenge. In normal pregnancies, misleading signs may be observed such as striae or hypokalemia, while plasma cortisol and urinary free cortisol may rise up to 2- to 3-fold. While the dexamethasone suppression test is difficult to use, reference values for salivary cortisol appear valid. Apart from gestational hypertension, differential diagnosis includes pheochromocytoma and primary aldosteronism. The predominant cause is adrenal adenoma (sometimes without decreased ACTH), rather than Cushing's disease. There are considerable imaging pitfalls in Cushing's disease. Aberrant receptors may, in rare cases, lead to increased cortisol production during pregnancy in response to HCG, LHRH, glucagon, vasopressin or after a meal. Adrenocortical carcinoma (ACC) is rare and has poor prognosis. Active CS during pregnancy is associated with a high rate of maternal complications: hypertension or preeclampsia, diabetes, fractures; more rarely, cardiac failure, psychiatric disorders, infection and maternal death. Increased fetal morbidity includes prematurity, intrauterine growth retardation and less prevalently stillbirth, spontaneous abortion, intrauterine death and hypoadrenalism. Therapy is also challenging. Milder cases can be managed conservatively by controlling comorbidities. Pituitary or adrenal surgery should ideally be performed during the second trimester and patients should then be treated for adrenal insufficiency. Experience with anticortisolic drugs is limited. Metyrapone was found to allow control of hypercortisolism, with a risk of worsening hypertension. Cabergoline may be an alternative option. The use of other drugs is not advised because of potential teratogenicity and/or lack of information. Non-hormonal (mechanical) contraception is recommended until sustained biological remission is obtained.

Urine protein electrophoresis study in dogs with pituitary dependent hyperadrenocorticism during therapy with trilostane / Avaliação da proteína urinária por eletroforese em cães com hiperadrenocorticismo hipófise dependente durante a terapia com trilostano

Hyperadrenocorticism is one of the most common endocrine disorders in dogs. Regarding to the kidneys, chronic hypercortisolemia can cause damage to the glomerulus, and evolve into chronic kidney disease. This study evaluated nine normotensive dogs with pituitary dependent hyperadrenocorticism, before and after therapy with trilostane, during the follow-up period of six months, in order to investigate the development of pathological proteinuria by quantitative (urinary protein-to-creatinine ratio) and qualitative (urinary protein electrophoresis) methods, and also to monitor its intensity over the course of the disease and therapy. The main renal lesion detected in dogs with hyperadrenocorticism was in the tubular segment, evidenced by the prevalence of urinary protein bands of lower molecular weight, indicating the lack absorption of these proteins in the proximal segment of the nephron. Low molecular weight proteins persisted throughout the follow-up. Regarding the future of routine veterinary medical clinic in the care of patients with hyperadrenocorticism, the assessments of proteinuria determinations by the urinary protein-to-creatinin ratio and urinary protein electrophoresis, according to the results obtained in this study, can add more information about the renal damage in these animals, and contribute to the prognosis.(AU)

Hiperadrenocorticismo (HAC) é uma das doenças endócrinas mais comuns em cães. A hipercortisolemia crônica pode causar danos glomerulares, pelo aumento da taxa de filtração glomerular, podendo levar ao desenvolvimento de doença renal crônica. Este estudo avaliou nove cães normotensos com hiperadrenocorticismo hipófise-dependente, antes e após a terapia com trilostano, durante o período de acompanhamento de seis meses, a fim de investigar o desenvolvimento de proteinúria patológica por métodos quantitativo (relação proteína e creatinina urinária) e qualitativos (eletroforese de proteínas urinárias) e também para monitorar a sua intensidade ao longo do curso da doença e terapia. A principal lesão renal detectada em cães com HAC foi no segmento tubular, evidenciada pela prevalência de bandas de proteínas urinárias de peso molecular mais baixo, indicando a falta de absorção destas proteínas no segmento proximal do néfron. A proteinúria de baixo peso molecular persistiu durante todo o acompanhamento. Em relação ao futuro da rotina clínica médica veterinária no tratamento de cães com hiperadrenocorticismo, as avaliações de proteinúria pela relação proteína e creatinina urinária e eletroforese de proteínas urinárias, de acordo com os resultados obtidos neste estudo, podem adicionar mais informações sobre a lesão renal nestes animais e contribuir para o prognóstico.(AU)

Optimization of left adrenal vein sampling in primary aldosteronism: Coping with asymmetrical cortisol secretion.

We evaluated the influence of catheter sampling position and size on left adrenal venous sampling (AVS) in patients with primary aldosteronism (PA) and analyzed their relationship to cortisol secretion. This retrospective study included 111 patients with a diagnosis of primary aldosteronism who underwent tetracosactide-stimulated AVS. Left AVS was obtained from two catheter positions - the central adrenal vein (CAV) and the common trunk. For common trunk sampling, 5-French catheters were used in 51 patients, and microcatheters were used in 60 patients. Autonomous cortisol secretion was evaluated with a low-dose dexamethasone suppression test in 87 patients. The adrenal/inferior vena cava cortisol concentration ratio [selectivity index (SI)] was significantly lower in samples from the left common trunk than those of the left CAV and right adrenal veins, but this difference was reduced when a microcatheter was used for common trunk sampling. Sample dilution in the common trunk of the left adrenal vein can be decreased by limiting sampling speed with the use of a microcatheter. Meanwhile, there was no significant difference in SI between the left CAV and right adrenal veins. Laterality, determined according to aldosterone/cortisol ratio (A/C ratio) based criteria, showed good reproducibility regardless of sampling position, unlike the absolute aldosterone value based criteria. However, in 11 cases with autonomous cortisol co-secretion, the cortisol hypersecreting side tended to be underestimated when using A/C ratio based criteria. Left CAV sampling enables symmetrical sampling, and may be essential when using absolute aldosterone value based criteria in cases where symmetrical cortisol secretion is uncertain.

Chronic Supplementation of Curcumin Enhances the Efficacy of Antidepressants in Major Depressive Disorder: A Randomized, Double-Blind, Placebo-Controlled Pilot Study.

Major depressive disorder is a devastating mental illness leading to a lifetime prevalence of higher than 16% on individuals. The treatment delay and inevitable adverse effects are major limitations of current depression interventions. Emerging evidence indicates that curcumin produced significant antidepressant properties in depression in both rodents and humans without adverse effects. Therefore, it is necessary to further clarify the antidepressant actions of curcumin and the underlying mechanism in depressed patients. A total of 108 male adults aged between 31 and 59 years were systematically recruited in Tianjin Anding Hospital. Subjects were administered the Chinese version of 17-item Hamilton Depression Rating Scale and Montgomery-Asberg Depression Rating Scale that measures different scores of depressive symptoms. The subjects were asked to take 2 capsules containing either 1000 mg of curcumin or placebo soybean powder daily for 6 weeks on the basis of their current antidepressant medications. The plasma levels of interleukin 1ß, tumor necrosis factor α, brain-derived neurotrophic factor, and salivary cortisol were measured by enzyme-linked immunosorbent assay before and after curcumin or placebo treatment during the 6-week procedure. Chronic supplementation with curcumin produced significant antidepressant behavioral response in depressed patients by reduction of 17-item Hamilton Depression Rating Scale and Montgomery-Asberg Depression Rating Scale scores. Furthermore, curcumin decreases inflammatory cytokines interleukin 1ß and tumor necrosis factor α level, increases plasma brain-derived neurotrophic factor levels, and decreases salivary cortisol concentrations compared with placebo group. These findings indicate the potential benefits of further implications of supplementary administration of curcumin to reverse the development of depression and enhance the outcome of antidepressants treatment in major depressive disorder.

Assessment of the potential of polyphenols as a CYP17 inhibitor free of adverse corticosteroid elevation.

Inhibition of 17α-hydroxylase/17,20-lyase (CYP17), which dictates the proceeding of androgen biosynthesis, is recommended as an effective treatment for androgen-dependent diseases. However, androgen depletion by selective CYP17 inhibition is accompanied with corticosteroid elevation, which increases risk of cardiovascular diseases. In this study, we evaluated the likelihood of polyphenols as a CYP17 inhibitor without cardiovascular complications. All examined polyphenols significantly inhibited CYP17 in human adrenocortical H295R cells, but their effects on androgen and cortisol biosynthesis were diverse. Resveratrol was the most potent CYP17 inhibitor with an approximate IC50 of 4 µM, and the inhibition might weigh on the 17α-hydroxylase activity more than the 17,20-lyase activity. Resveratrol also inhibited 21α-hydroxylase (CYP21) essential for corticosteroid biosynthesis but to a lesser extent, thus preventing the occurrence of cortisol elevation following CYP17 blockade. Although transcriptional down-regulation was important for α-naphthoflavone-mediated CYP17 inhibition, resveratrol inhibited CYP17 and CYP21 mainly at the level of enzyme activity rather than enzyme abundance and cytochrome P450 electron transfer. Daidzein also inhibited CYP17 and CYP21 although less potent than resveratrol. Daidzein was the only polyphenol showing inhibition of 3ß-hydroxysteroid dehydrogenase type II (3ßHSD2). The exceptional 3ßHSD2 inhibition led to dehydroepiandrosterone accumulation alongside daidzein-caused androgen biosynthetic impairment. In contrast, androgen and cortisol secretion was increased or remained normal under α-naphthoflavone and ß-naphthoflavone treatments, suggesting that CYP17 inhibition was counteracted by increased substrate generation. α-naphthoflavone and ß-naphthoflavone also enhanced the formation of cortisol from 17-hydroxyprogesterone and testosterone from androstenedione. Our findings suggest a potential application of resveratrol in androgen deprivation therapy.

Identification of novel 11ß-HSD1 inhibitors by combined ligand- and structure-based virtual screening.

11 beta-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) converts cortisone to cortisol in a NADPH dependent manner. Overexpression of 11ß-HSD1 in key metabolic tissues is related to the development of type 2 diabetes, obesity, hypertension and metabolic syndrome. Using crystal structures of human 11ß-HSD1 in complex with inhibitors as source of structural information, a combined ligand and structure-based virtual screening approach was implemented to identify novel 11ß-HSD1 inhibitors. A selected group of compounds was identified in silico and further evaluated in cell-based assays for cytotoxicity and 11ß-HSD1 mediated cortisol production inhibitory capacity. The expression of 11ß-HSD1 and 11ß-HSD2 in human LS14 adipocytes was assessed during differentiation. Biological evaluation of 39 compounds in adipocytes and steroids quantification by HPLC-MS/MS identify 4 compounds that exhibit 11ß-HSD1 mediated cortisol production inhibitory activity with potencies in the micromolar range. Two compounds showed to be selective for the 11ß-HSD1 reductase activity and over 11ß-HSD2 isoform, and thus represent novel leads for the development of more active derivatives with higher efficacies targeting intracellular cortisol levels in type 2 diabetes and metabolic syndrome.

Mitotane exhibits dual effects on steroidogenic enzymes gene transcription under basal and cAMP-stimulating microenvironments in NCI-H295 cells.

Adrenocortical carcinoma (ACC) is an extremely rare and aggressive endocrine malignancy with a poor prognosis. The most common symptom of ACC is hypercortisolism (Cushing's syndrome), which has the highest mortality. Mitotane is used as a steroidogenesis inhibitor for Cushing's syndrome or as a chemical adrenalectomy drug for ACC. Mitotane induces adrenal cortex necrosis, mitochondrial membrane impairment, and irreversible binding to CYP proteins. In this study, we explored the molecular effect of mitotane on steroidogenesis in human adrenocortical cancer NCI-H295 cells. Mitotane (10-40µM) inhibited basal and cAMP-induced cortisol secretion but did not cause cell death. Mitotane exhibited an inhibitory effect on the basal expression of StAR and P450scc protein. Furthermore, 40µM of mitotane significantly diminished StAR, CYP11A1 and CYP21 mRNA expression. HSD3B2 and CYP17 seem to be insensitive to mitotane. The stimulatory effects of mitotane on CYP11B1 were more remarkable than its inhibitory effects. In contrast, the activation of cAMP signaling strongly elevated the expression of all these genes. Mitotane (40µM) almost completely neutralized this positive effect and returned 8-Br-cAMP-induced StAR, CYP11A1, CYP17 and CYP21 mRNA to control levels. After cAMP activation, mitotane did not change the levels of CYP11B1 mRNA. The present study demonstrates that mitotane can inhibit cortisol biosynthesis due to a non-specific interference with the gene transcription of steroidogenic enzymes under both basal and 8-Br-cAMP-activated conditions in NCI-H295 cells. We also identified that StAR and CYP11A1 key enzymes that participate in the rate-limiting step of steroidogenesis, were more sensitive to mitotane. In addition, the biphasic effect of mitotane on CYP11B1 was also elucidated.

[Recent progress in the treatment of Cushing's disease]. / Traitement de la maladie de Cushing : progrès récents.

Transsphenoidal surgery, possibly through the endoscopic approach, remains the first line treatment. Opposing cortisol action with mifepristone proved efficacious in some individual cases but but with major monitoring difficulties. Combined treatment with three anticortisolic drugs (metyrapone, ketokonazole, O,p'DDD) is particularly attractive in severe cases. The Nelson's syndrome has been revisited, and the corticotroph tumor progression should rather be cautiously assessed after bilateral adrenalectomy. Two molecules potentially act directly to suppress the ACTH secretion by the corticotroph adenoma: agonists of the D2 Dopamine receptor and of the somatostatin receptor type 5. Their efficacy remains modest (20 to 30% of the patients actually normalize urinary cortisol). Pituitary radiotherapy can be efficiently performed by stereotaxic approach.

Orteronel (TAK-700), a novel non-steroidal 17,20-lyase inhibitor: effects on steroid synthesis in human and monkey adrenal cells and serum steroid levels in cynomolgus monkeys.

Surgical or pharmacologic methods to control gonadal androgen biosynthesis are effective approaches in the treatment of a variety of non-neoplastic and neoplastic diseases. For example, androgen ablation and its consequent reduction in circulating levels of testosterone is an effective therapy for advanced prostate cancers. Unfortunately, the therapeutic effectiveness of this approach is often temporary because of disease progression to the 'castration resistant' (CRPC) state, a situation for which there are limited treatment options. One mechanism thought to be responsible for the development of CRPC is extra-gonadal androgen synthesis and the resulting impact of these residual extra-gonadal androgens on prostate tumor cell proliferation. An important enzyme responsible for the synthesis of extra-gonadal androgens is CYP17A1 which possesses both 17,20-lyase and 17-hydroxylase catalytic activities with the 17,20-lyase activity being key in the androgen biosynthetic process. Orteronel (TAK-700), a novel, selective, and potent inhibitor of 17,20-lyase is under development as a drug to inhibit androgen synthesis. In this study, we quantified the inhibitory activity and specificity of orteronel for testicular and adrenal androgen production by evaluating its effects on CYP17A1 enzymatic activity, steroid production in monkey adrenal cells and human adrenal tumor cells, and serum levels of dehydroepiandrosterone (DHEA), cortisol, and testosterone after oral dosing in castrated and intact male cynomolgus monkeys. We report that orteronel potently suppresses androgen production in monkey adrenal cells but only weakly suppresses corticosterone and aldosterone production; the IC(50) value of orteronel for cortisol was ~3-fold higher than that for DHEA. After single oral dosing, serum levels of DHEA, cortisol, and testosterone were rapidly suppressed in intact cynomolgus monkeys. In castrated monkeys treated twice daily with orteronel, suppression of DHEA and testosterone persisted throughout the treatment period. In both in vivo models and in agreement with our in vitro data, suppression of serum cortisol levels following oral dosing was less than that seen for DHEA. In terms of human CYP17A1 and human adrenal tumor cells, orteronel inhibited 17,20-lyase activity 5.4 times more potently than 17-hydroxylase activity in cell-free enzyme assays and DHEA production 27 times more potently than cortisol production in human adrenal tumor cells, suggesting greater specificity of inhibition between 17,20-lyase and 17-hydroxylase activities in humans vs monkeys. In summary, orteronel potently inhibited the 17,20-lyase activity of monkey and human CYP17A1 and reduced serum androgen levels in vivo in monkeys. These findings suggest that orteronel may be an effective therapeutic option for diseases where androgen suppression is critical, such as androgen sensitive and CRPC.

Effects of cortisol on pregnancy rate and corpus luteum function in heifers: an in vivo study.

To determine whether glucocorticoids affect the function of the bovine corpus luteum (CL) during the estrous cycle and early pregnancy, we examined the effects of exogenous cortisol or reduced endogenous cortisol on the secretion of progesterone (P4) and on pregnancy rate. In preliminary experiments, doses of cortisol and metyrapone (an inhibitor of cortisol synthesis) were established (n=33). Cortisol in effective doses of 10 mg blocked tumor necrosis factor-induced prostaglandin F(2α) secretion as measured by its metabolite (PGFM) concentrations in the blood. Metyrapone in effective doses of 500 mg increased the P4 concentration. Thus, both reagents were then intravaginally applied in the chosen doses daily from Day 15 to 18 after estrus (Day 0) in noninseminated heifers (n=18) or after artificial insemination (n=36). Pregnancy was confirmed by transrectal ultrasonography between Days 28-30 after insemination. Plasma concentrations of P4 were lower in cortisol-treated heifers than in control heifers on Days 17 and 18 of the estrous cycle (P<0.05). However, the interestrus intervals were not different between control and cortisol-treated animals (P>0.05). Moreover, metyrapone increased P4 and prolonged the CL lifespan in comparison to control animals (P<0.05). Interestingly, in inseminated heifers, cortisol increased the pregnancy rate (75%) compared with control animals (58%), whereas metyrapone reduced the pregnancy rate to 16.7% (P<0.05). The overall results suggest that cortisol, depending on the physiological status of heifers (pregnant vs. nonpregnant), modulates CL function by influencing P4 secretion. Cortisol may have a positive influence on CL function during early pregnancy, leading to support of embryo implantation and resulting in higher rates of pregnancy in heifers.

Cushing's syndrome: all variants, detection, and treatment.

Diagnosis of Cushing's syndrome involves a step-wise approach and establishing the cause can be challenging. Several pathogenic mechanisms have been proposed for glucocorticoid-induced hypertension, including a functional mineralocorticoid excess state, upregulation of the renin angiotensin system, and deleterious effects of cortisol on the vasculature. Surgical excision of the cause of excess glucocorticoids remains the optimal treatment. Antiglucocorticoid and antihypertensive agents and steroidogenesis inhibitors can be used as adjunctive treatment modalities in preparation for surgery and in cases where surgery is contraindicated or has not led to cure.

Cadmium-mediated disruption of cortisol biosynthesis involves suppression of corticosteroidogenic genes in rainbow trout.

Cadmium is widely distributed in the aquatic environment and is toxic to fish even at sublethal concentrations. This metal is an endocrine disruptor, and one well established role in teleosts is the suppression of adrenocorticotrophic hormone (ACTH)-stimulated cortisol biosynthesis by the interrenal tissue. However the mechanism(s) leading to this steroid suppression is poorly understood. We tested the hypothesis that cadmium targets genes encoding proteins critical for corticosteroid biosynthesis, including melanocortin 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleavage enzyme (P450scc), in rainbow trout (Oncorhynchus mykiss). To test this, head kidney slices (containing the interrenal tissues) were incubated in vitro with cadmium chloride (0, 10, 100 and 1000nM) for 4h either in the presence or absence of ACTH (0.5IU/mL). In the unstimulated head kidney slices, cadmium exposure did not affect basal cortisol secretion and the mRNA levels of MC2R and P450scc, while StAR gene expression was significantly reduced. Cadmium exposure significantly suppressed ACTH-stimulated cortisol production in a dose-related fashion. This cadmium-mediated suppression in corticosteroidogenesis corresponded with a significant reduction in MC2R, StAR and P450scc mRNA levels in trout head kidney slices. The inhibition of ACTH-stimulated cortisol production and suppression of genes involved in corticosteroidogenesis by cadmium were completely abolished in the presence of 8-Bromo-cAMP (a cAMP analog). Overall, cadmium disrupts the expression of genes critical for corticosteroid biosynthesis in rainbow trout head kidney slices. However, the rescue of cortisol production as well as StAR and P450scc gene expressions by cAMP analog suggests that cadmium impact occurs upstream of cAMP production. We propose that MC2R signaling, the primary step in ACTH-induced cortocosteroidogenesis, is a key target for cadmium-mediated disruption of cortisol production in trout.

Endogenous cortisol and TGF-beta in human aqueous humor contribute to ocular immune privilege by regulating dendritic cell function.

Aqueous humor (AqH) has been shown to have significant immunosuppressive effects on APCs in animal models. We wanted to establish whether, in humans, AqH can regulate dendritic cell (DC) function and to identify the dominant mechanism involved. Human AqH inhibited the capacity of human peripheral blood monocyte-derived DC to induce naive CD4(+) T cell proliferation and cytokine production in vitro, associated with a reduction in DC expression of the costimulatory molecule CD86. This was seen both for DC cultured under noninflammatory conditions (immature DC) and for DC stimulated by proinflammatory cytokines (mature DC). DC expression of MHC classes I/II and CD83 was reduced (mature DC only). Myeloid DC from peripheral blood were similarly sensitive to the effects of human AqH, but only under inflammatory conditions. The addition of α-melanocyte stimulating hormone and vasoactive intestinal peptide did not cause significant inhibition at physiological levels. However, the addition of exogenous cortisol at physiological levels recapitulated the AqH-induced reduction in CD86 and inhibition of DC-induced T cell proliferation, and blockade of cortisol in AqH partially reversed its suppressive effects. TGF-ß2 had an additional effect with cortisol, and although simultaneous blockade of cortisol and TGF-ß2 in AqH reduced its effectiveness, there was still a cortisol- and TGF-ß-independent component. In humans, AqH regulates DC maturation and function by the combined actions of cortisol and TGF-ß2, a pathway that is likely to contribute to the maintenance of immune privilege in the eye.

Medical therapy of Cushing's disease: where are we now?

The goals of ideal medical therapy for Cushing's disease should be to target the aetiology of the disorder, and thus surgery is the current 'gold standard' treatment. However, no effective drug that directly and effectively targets the adrenocorticotropin-secreting pituitary adenoma has been found to date, and treatments to control the hypercortisolaemic state by adrenal-based therapy are frequently used. Inhibitors of adrenal steroidogenesis, adrenolytic agents, compounds with neuromodulatory properties, and ligands of different nuclear hormone receptors involved in hypothalamo-pituitary regulation currently used have been reviewed. Ketoconazole and metyrapone can control hypercortisolaemicstates, as well as mitotane in selective cases, depending on their side effects and frequent monitoring. The somatostatin analogue pasireotide and the dopamine agonist cabergoline, as well as their combination, show some therapeutic promise, while retinoic acid analogues should be further investigated in the pituitary-targeted medical therapy of Cushing's disease. Since a percentage of patients treated with surgery are not cured, or improve and subsequently relapse, there is an urgent need for effective medical therapies for this disorder. At present, only cabergoline and pasireotide are under active investigation, while adrenal steroidogenesis inhibitors are still the mainstay treatments for the control of the hypercortisolaemic state.

A specific CRH antagonist attenuates ACTH-stimulated cortisol secretion in ovine adrenocortical cells.

Corticotropin releasing hormone (CRH) has been detected in the adrenal gland of many species and may be involved in regulation of glucocorticoid secretion. In cultured human fetal adrenal definitive/transitional zone cells, CRH upregulates the adrenocorticotropic hormone (ACTH) receptor and steroidogenic enzymes and is blocked by the selective CRH type 1 receptor (CRH(1)) antagonist, antalarmin. Based on these findings and evidence that antalarmin infusion into sheep suppressed prepartum increases in cortisol, we hypothesized that antalarmin would influence adrenal cortisol secretion. Antalarmin strongly attenuated ACTH and forskolin (FSK)-stimulated cortisol and cyclic adenosine monophosphate (cAMP) release from cultured ovine adrenocortical cells but did not prevent ACTH binding to cells or ACTH-induced proliferation in adult cells. Corticotropin releasing hormone was minimally effective as a secretagogue but increased the cortisol response to subsequent ACTH. These results suggest that antalarmin attenuates ACTH-induced cortisol secretion from cultured ovine adrenal cortical cells at a site distal to the ACTH receptor. Although CRH may modulate the secretory response to ACTH, it is probably not a direct cortisol secretagogue in the sheep.

Induction of progesterone receptor A form attenuates the induction of cytosolic phospholipase A2alpha expression by cortisol in human amnion fibroblasts.

Cytosolic phospholipase A2alpha (cPLA(2alpha), now known as PLA2G4A) is the enzyme catalyzing the formation of the rate-limiting substrate, arachidonic acid, for prostaglandin (PG) synthesis. The increasing expression of PLA2G4A toward term gestation in human amnion fibroblasts is believed to be the crucial event in parturition. Human amnion fibroblasts produce cortisol, progesterone and express glucocorticoid receptor (GR), progesterone receptor A (PGRA) form at term. The roles of progesterone and PGRA in the induction of PLA2G4A by cortisol via GR in the amnion fibroblasts remain largely unknown. Using cultured human term amnion fibroblasts, we found that cortisol induced the expression of PGRA, which was attenuated by inhibiting PG synthesis with indomethacin. Knockdown of PGRA expression or inhibition of endogenous progesterone production with trilostane significantly enhanced the induction of PLA2G4A by cortisol, whereas overexpression of PGRA attenuated the induction of PLA2G4A by cortisol. Although exogenous progesterone did not alter PLA2G4A expression under basal conditions, it attenuated cortisol-induced PLA2G4A expression at concentrations about tenfold higher, which might be achieved by competition with cortisol for GR. In conclusion, PGRA in the presence of endogenous progesterone is a transdominant repressor of the induction of PLA2G4A by cortisol. High level of progesterone may compete with cortisol for GR, thus further inhibiting the induction of PLA2G4A by cortisol. Moreover, increased PG synthesis by cortisol may feed back on the expression of PGRA leading to attenuation of cortisol-induced PLA2G4A expression. The above findings may be pertinent to the inconsistent effects of glucocorticoids on parturition in humans.

Pharmacological use of progesterone and 17-alpha-hydroxyprogesterone caproate in the prevention of preterm delivery.

Preterm delivery (PTD) is defined by the World Health Organization as birth before 37 completed weeks of gestation. In Western countries, PTD accounts for over 75% of all perinatal morbidity and mortality. The social importance of PTD derives from the consideration that it causes near three quarter of neonatal deaths not caused by malformations. Progesterone is a steroid hormone which plays a crucial role in each step of human pregnancy. Early in pregnancy progesterone is produced by the corpus luteum and it is fundamental for pregnancy maintenance until placenta takes over this function at 7-9 weeks of gestation. Late in pregnancy, the role of progesterone is less clear: certainly, it may be importance in maintaining uterine quiescence in the latter half of pregnancy by limiting the production of stimulatory prostaglandins and inhibiting the expression of contraction-associated protein genes (ion channels, oxytocin and prostaglandin receptors, and gap junctions) within the myometrium. In this review, the authors included those controlled clinical studies that have used either 17 hydroxy progesterone caproate (17P), or progesterone (P) or its synthetic derivatives (progestins) in order to avoid or reduce the incidence of preterm delivery, in populations of women at increased risk of preterm birth. The authors conclude that: 1) the treatment with 17P reduces the incidence of PTD in pluriparous women with a previous history of PTD or with recurrent abortion, as well as in nulliparous women with an actual risk; 2) the treatment with P reduces PTD in nulliparous women, namely in the presence of a silent cervical shortening; 3) 17P has no efficacy in multiple pregnancy and it is proven not to have adverse effects on the infants.

Model-based therapeutic correction of hypothalamic-pituitary-adrenal axis dysfunction.

The hypothalamic-pituitary-adrenal (HPA) axis is a major system maintaining body homeostasis by regulating the neuroendocrine and sympathetic nervous systems as well modulating immune function. Recent work has shown that the complex dynamics of this system accommodate several stable steady states, one of which corresponds to the hypocortisol state observed in patients with chronic fatigue syndrome (CFS). At present these dynamics are not formally considered in the development of treatment strategies. Here we use model-based predictive control (MPC) methodology to estimate robust treatment courses for displacing the HPA axis from an abnormal hypocortisol steady state back to a healthy cortisol level. This approach was applied to a recent model of HPA axis dynamics incorporating glucocorticoid receptor kinetics. A candidate treatment that displays robust properties in the face of significant biological variability and measurement uncertainty requires that cortisol be further suppressed for a short period until adrenocorticotropic hormone levels exceed 30% of baseline. Treatment may then be discontinued, and the HPA axis will naturally progress to a stable attractor defined by normal hormone levels. Suppression of biologically available cortisol may be achieved through the use of binding proteins such as CBG and certain metabolizing enzymes, thus offering possible avenues for deployment in a clinical setting. Treatment strategies can therefore be designed that maximally exploit system dynamics to provide a robust response to treatment and ensure a positive outcome over a wide range of conditions. Perhaps most importantly, a treatment course involving further reduction in cortisol, even transient, is quite counterintuitive and challenges the conventional strategy of supplementing cortisol levels, an approach based on steady-state reasoning.