Phase 2 Trial of Baxdrostat for Treatment-Resistant Hypertension.

BACKGROUND: Aldosterone synthase controls the synthesis of aldosterone and has been a pharmacologic target for the treatment of hypertension for several decades. Selective inhibition of aldosterone synthase is essential but difficult to achieve because cortisol synthesis is catalyzed by another enzyme that shares 93% sequence similarity with aldosterone synthase. In preclinical and phase 1 studies, baxdrostat had 100:1 selectivity for enzyme inhibition, and baxdrostat at several dose levels reduced plasma aldosterone levels but not cortisol levels. METHODS: In this multicenter, placebo-controlled trial, we randomly assigned patients who had treatment-resistant hypertension, with blood pressure of 130/80 mm Hg or higher, and who were receiving stable doses of at least three antihypertensive agents, including a diuretic, to receive baxdrostat (0.5 mg, 1 mg, or 2 mg) once daily for 12 weeks or placebo. The primary end point was the change in systolic blood pressure from baseline to week 12 in each baxdrostat group as compared with the placebo group. RESULTS: A total of 248 patients completed the trial. Dose-dependent changes in systolic blood pressure of -20.3 mm Hg, -17.5 mm Hg, -12.1 mm Hg, and -9.4 mm Hg were observed in the 2-mg, 1-mg, 0.5-mg, and placebo groups, respectively. The difference in the change in systolic blood pressure between the 2-mg group and the placebo group was -11.0 mm Hg (95% confidence interval [CI], -16.4 to -5.5; P<0.001), and the difference in this change between the 1-mg group and the placebo group was -8.1 mm Hg (95% CI, -13.5 to -2.8; P = 0.003). No deaths occurred during the trial, no serious adverse events were attributed by the investigators to baxdrostat, and there were no instances of adrenocortical insufficiency. Baxdrostat-related increases in the potassium level to 6.0 mmol per liter or greater occurred in 2 patients, but these increases did not recur after withdrawal and reinitiation of the drug. CONCLUSIONS: Patients with treatment-resistant hypertension who received baxdrostat had dose-related reductions in blood pressure. (Funded by CinCor Pharma; BrigHTN ClinicalTrials.gov number, NCT04519658.).

Efficacy and safety of aldosterone synthase inhibition with and without empagliflozin for chronic kidney disease: a randomised, controlled, phase 2 trial.

BACKGROUND: Excess aldosterone accelerates chronic kidney disease progression. This phase 2 clinical trial assessed BI 690517, an aldosterone synthase inhibitor, for efficacy, safety, and dose selection. METHODS: This was a multinational, randomised, controlled, phase 2 trial. People aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 30 to less than 90 mL/min/1·73 m2, a urine albumin to creatinine ratio (UACR) of 200 to less than 5000 mg/g, and serum potassium of 4·8 mmol/L or less, taking an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, were enrolled. Participants were randomly assigned (1:1) to 8 weeks of empagliflozin or placebo run-in, followed by a second randomisation (1:1:1:1) to 14 weeks of treatment with once per day BI 690517 at doses of 3 mg, 10 mg, or 20 mg, or placebo. Study participants, research coordinators, investigators, and the data coordinating centre were masked to treatment assignment. The primary endpoint was the change in UACR measured in first morning void urine from baseline (second randomisation) to the end of treatment. This study is registered with ClinicalTrials.gov (NCT05182840) and is completed. FINDINGS: Between Feb 18 and Dec 30, 2022, of the 714 run-in participants, 586 were randomly assigned to receive BI 690517 or placebo. At baseline, 33% (n=196) were women, 67% (n=390) were men, 42% (n=244) had a racial identity other than White, and mean participant age was 63·8 years (SD 11·3). Mean baseline eGFR was 51·9 mL/min/1·73 m2 (17·7) and median UACR was 426 mg/g (IQR 205 to 889). Percentage change in first morning void UACR from baseline to the end of treatment at week 14 was -3% (95% CI -19 to 17) with placebo, -22% (-36 to -7) with BI 690517 3 mg, -39% (-50 to -26) with BI 690517 10 mg, and -37% (-49 to -22) with BI 690517 20 mg monotherapy. BI 690517 produced similar UACR reductions when added to empagliflozin. Investigator-reported hyperkalaemia occurred in 10% (14/146) of those in the BI 690517 3 mg group, 15% (22/144) in the BI 690517 10 mg group, and 18% (26/146) in the BI 690517 20 mg group, and in 6% (nine of 147) of those receiving placebo, with or without empagliflozin. Most participants with hyperkalaemia did not require intervention (86% [72/84]). Adrenal insufficiency was an adverse event of special interest reported in seven of 436 study participants (2%) receiving BI 690517 and one of 147 participants (1%) receiving matched placebo. No treatment-related deaths occurred during the study. INTERPRETATION: BI 690517 dose-dependently reduced albuminuria with concurrent renin-angiotensin system inhibition and empagliflozin, suggesting an additive efficacy for chronic kidney disease treatment without unexpected safety signals. FUNDING: Boehringer Ingelheim.

The Renin-Angiotensin-Aldosterone System Regulates Sarcoidosis Granulomatous Inflammation.

Rationale: Sarcoidosis is a granulomatous disorder of unclear cause notable for abnormal elevation of blood and tissue ACE1 (angiotensin converting enzyme 1) levels and activity. ACE1 regulates the renin-angiotensin-aldosterone system (RAAS), the terminal product of which is aldosterone, which selectively engages mineralocorticoid receptors to promote inflammation. Objectives: We sought to determine whether the RAAS promotes sarcoidosis granuloma formation and related inflammatory responses. Methods: Using an established ex vivo model, we first determined whether aldosterone was produced by sarcoidosis granulomas and verified the presence of CYP11B2, the enzyme required for its production. We then evaluated the effects of selective inhibitors of ACE1 (captopril), angiotensin type 1 receptor (losartan), and mineralocorticoid receptors (spironolactone, eplerenone) on granuloma formation, reflected by computer image analysis-generated granuloma area, and selected cytokines incriminated in sarcoidosis pathogenesis. Measurements and Main Results: Aldosterone was spontaneously produced by sarcoidosis peripheral blood mononuclear cells, and both intra- and extracellular levels steadily increased during granuloma formation. In parallel, peripheral blood mononuclear cells were shown to express more CYP11B2 during granuloma formation. Significant inhibition of sarcoidosis granulomas and related cytokines (TNFα, IL-1ß, IFNγ, IL-10) was observed in response to pretreatments with captopril, losartan, spironolactone, or eplerenone, comparable to that of prednisone. Conclusions: The RAAS is intact in sarcoidosis granulomas and contributes significantly to early granuloma formation and to related inflammatory mediator responses, with important implications for clinical management.

Kinetics of Intermediate Release Enhances P450 11B2-Catalyzed Aldosterone Synthesis.

The mitochondrial enzyme cytochrome P450 11B2 (aldosterone synthase) catalyzes the 3 terminal transformations in the biosynthesis of aldosterone from 11-deoxycorticosterone (DOC): 11ß-hydroxylation to corticosterone, 18-hydroxylation, and 18-oxidation. Prior studies have shown that P450 11B2 produces more aldosterone from DOC than from the intermediate corticosterone and that the reaction sequence is processive, with intermediates remaining bound to the active site between oxygenation reactions. In contrast, P450 11B1 (11ß-hydroxylase), which catalyzes the terminal step in cortisol biosynthesis, shares a 93% amino acid sequence identity with P450 11B2, converts DOC to corticosterone, but cannot synthesize aldosterone from DOC. The biochemical and biophysical properties of P450 11B2, which enable its unique 18-oxygenation activity and processivity, yet are not also represented in P450 11B1, remain unknown. To understand the mechanism of aldosterone biosynthesis, we introduced point mutations at residue 320, which partially exchange the activities of P450 11B1 and P450 11B2 (V320A and A320V, respectively). We then investigated NADPH coupling efficiencies, binding kinetics and affinities, and product formation of purified P450 11B1 and P450 11B2, wild-type, and residue 320 mutations in phospholipid vesicles and nanodiscs. Coupling efficiencies for the 18-hydroxylase reaction with corticosterone as the substrate failed to correlate with aldosterone synthesis, ruling out uncoupling as a relevant mechanism. Conversely, corticosterone dissociation rates correlated inversely with aldosterone production. We conclude that intermediate dissociation kinetics, not coupling efficiency, enable P450 11B2 to synthesize aldosterone via a processive mechanism. Our kinetic data also suggest that the binding of DOC to P450 11B enzymes occurs in at least two distinct steps, favoring an induced-fit mechanism.

Aldosterone and aldosterone synthase inhibitors in cardiorenal disease.

Modulation of the renin-angiotensin-aldosterone system is a foundation of therapy for cardiovascular and kidney diseases. Excess aldosterone plays an important role in cardiovascular disease, contributing to inflammation, fibrosis, and dysfunction in the heart, kidneys, and vasculature through both genomic and mineralocorticoid receptor (MR)-mediated as well as nongenomic mechanisms. MR antagonists have been a key therapy for attenuating the pathologic effects of aldosterone but are associated with some side effects and may not always adequately attenuate the nongenomic effects of aldosterone. Aldosterone is primarily synthesized by the CYP11B2 aldosterone synthase enzyme, which is very similar in structure to other enzymes involved in steroid biosynthesis including CYP11B1, a key enzyme involved in glucocorticoid production. Lack of specificity for CYP11B2, off-target effects on the hypothalamic-pituitary-adrenal axis, and counterproductive increased levels of bioactive steroid intermediates such as 11-deoxycorticosterone have posed challenges in the development of early aldosterone synthase inhibitors such as osilodrostat. In early-phase clinical trials, newer aldosterone synthase inhibitors demonstrated promise in lowering blood pressure in patients with treatment-resistant and uncontrolled hypertension. It is therefore plausible that these agents offer protection in other disease states including heart failure or chronic kidney disease. Further clinical evaluation will be needed to clarify the role of aldosterone synthase inhibitors, a promising class of agents that represent a potentially major therapeutic advance.

Methods Article for a Study Protocol: Study Design and Baseline Characteristics for Aldosterone Synthase Inhibition in Chronic Kidney Disease.

INTRODUCTION: Aldosterone synthase (AS) inhibition may overcome increased aldosterone production in response to renin-angiotensin system inhibition. BI 690517 is an AS inhibitor under investigation for chronic kidney disease (CKD). METHODS: This multinational, phase II, double-blind study (NCT05182840) investigated the efficacy and safety of daily oral BI 690517, with or without empagliflozin 10 mg, in participants with CKD. The primary endpoint was change from baseline in urine albumin:creatinine ratio (UACR) at week 14. Between February 18, 2022, and December 30, 2022, 714 adults already treated by angiotensin-converting enzyme inhibitor (30.5%) or angiotensin receptor blocker (69.8%) were randomized (1:1) to an 8-week run-in to assign background empagliflozin (n = 356) or placebo (n = 358). Participants in each group were then randomized (1:1:1:1) to a 14-week treatment period with BI 690517 (3 mg, 10 mg, or 20 mg) or placebo. Of the 714 participants who entered run-in, 586 were randomized to the treatment period. They were predominantly men (66.6%) of white race (58.4%) with a mean (standard deviation [SD]) age of 63.8 (11.3) years. Type 2 diabetes was present in 414 participants (70.6%). The baseline mean (SD) estimated glomerular filtration rate was 51.9 (17.7) mL/min/1.73 m2, and median (interquartile range) UACR was 426.3 mg/g (205.3-888.5). CONCLUSION: This study will inform dose selection for further clinical development and determine whether BI 690517, with or without background empagliflozin, has a favorable safety profile and potential for additive kidney protection in participants with CKD already treated with a renin-angiotensin system inhibitor.

Aldosterone synthase inhibitor (BI 690517) therapy for people with diabetes and albuminuric chronic kidney disease: A multicentre, randomized, double-blind, placebo-controlled, Phase I trial.

AIM: This Phase I study evaluated the safety and early efficacy of an aldosterone synthase inhibitor (BI 690517) in people with diabetes and albuminuric chronic kidney disease. METHODS: Double-blind, placebo-controlled study (NCT03165240) at 40 sites across Europe. Eligible participants [estimated glomerular filtration rate ≥20 and <75 ml/min/1.73 m2; urine albumin/creatinine ratio (UACR) ≥200 and <3500 mg/g] were randomized 6:1 to receive once-daily oral BI 690517 3, 10 or 40 mg, or eplerenone 25-50 mg, or placebo, for 28 days. The primary endpoint was the proportion of participants with drug-related adverse events (AEs). Secondary endpoints included changes from baseline in the UACR. RESULTS: Fifty-eight participants were randomized and treated from 27 November 2017 to 16 April 2020 (BI 690517: 3 mg, n = 18; 10 mg, n = 13; 40 mg, n = 14; eplerenone, n = 4; placebo, n = 9) for 28 days. Eight (13.8%) participants experienced drug-related AEs [BI 690517: 3 mg (two of 18); 10 mg (four of 13); 40 mg (two of 14)], most frequently constipation [10 mg (one of 13); 40 mg (one of 14)] and hyperkalaemia [3 mg (one of 18); 10 mg (one of 13)]. Most AEs were mild to moderate; one participant experienced severe hyperkalaemia (serum potassium 6.9 mmol/L; BI 690517 10 mg). UACR responses [≥20% decrease from baseline (first morning void urine) after 28 days] were observed for 80.0% receiving BI 690517 40 mg (eight of 10) versus 37.5% receiving placebo (three of eight). Aldosterone levels were suppressed by BI 690517, but not eplerenone or placebo. CONCLUSIONS: BI 690517 was generally well tolerated, reduced plasma aldosterone and may decrease albuminuria in participants with diabetes and albuminuric chronic kidney disease.

Identification of sulfonylpyrimidines as novel selective aldosterone synthase (CYP11B2) inhibitors.

4-[(5-[2-Methyl-5-(methylsulfonyl)pentan-2-yl]sulfonylpyrimidin-4-yl)amino]benzonitrile 2 was identified as a novel potent aldosterone synthase inhibitor. Compound 2 was found to inhibit human CYP11B2 in the nanomolar range, and showed an aldosterone-lowering effect in a furosemide-treated cynomolgus monkey model. Although human CYP11B2 has the high homology sequence with human CYP11B1, compound 2 showed more than 80 times higher selectivity over human CYP11B1 in vitro.

AGT, CYP11B2 & ADRB2 gene polymorphism & essential hypertension (HT): A meta-analysis.

Background & objectives The results of the genetic association studies between the selected candidate genes and hypertension (HT) contradicted across different populations. Majority of the meta-analyses carried out did not consider population genetic ancestry as a confounding factor. Therefore, this meta-analysis attempted to consolidate and re-evaluate the findings of the association between the selected candidate variants (AGT-rs699, CYP11B2-rs1799998, ADRB2-rs1042713 and rs1042714) and HT, by categorizing the genotyping data based on known genetic ancestry, and/or major geographical populations. Methods Publications were retrieved from PubMed, Cochrane and World of Science. The included articles were further divided into different populations based on their known genetic and/or geographical ancestry. Results AGTrs699-G was significantly associated with HT among Indians for (i) allele [P=0.03, Odds ratio (OR): 1.37, 95% Confidence Interval (CI): 1.03-1.82], and (ii) dominant mode of inheritance (P=0.009, OR:1.45, 95% CI: 1.09-1.91). CYP11B2rs1799998-G was significantly associated with HT in Europeans for (i) allele (P=6.9 × 10-5, OR: 0.82, 95% CI: 0.74-0.9), (ii) recessive (P=6.38 × 10-5, OR: 0.7, 95% CI: 0.59-0.83) and (iii) dominant mode of inheritance (P=0.008, OR: 0.81, 95% CI: 0.7-0.94). ADRB2-rs1042713-G was significantly associated with HT in east Asians for (i) allele (P=0.01, OR: 1.26, 95% CI: 1.05-1.51), and (ii) recessive mode of inheritance (P=0.04, OR: 1.36, 95% CI: 1.01-1.83). Interpretation & conclusions Different genotype and allele frequencies in diverse populations result in different genetic associations with HT across populations. This meta-analysis finding provides an update and summary of the genetic association between the selected simple nucleotide polymorphism (SNPs) and HT across different populations and essential insights into selecting appropriate pharmacogenetic marker(s) for effective HT management in populations of different ancestries.

Enhanced Ca2+ signaling, mild primary aldosteronism, and hypertension in a familial hyperaldosteronism mouse model (Cacna1hM1560V/+ ).

Gain-of-function mutations in the CACNA1H gene (encoding the T-type calcium channel CaV3.2) cause autosomal-dominant familial hyperaldosteronism type IV (FH-IV) and early-onset hypertension in humans. We used CRISPR/Cas9 to generate Cacna1hM1560V/+ knockin mice as a model of the most common FH-IV mutation, along with corresponding knockout mice (Cacna1h-/- ). Adrenal morphology of both Cacna1hM1560V/+ and Cacna1h-/- mice was normal. Cacna1hM1560V/+ mice had elevated aldosterone:renin ratios (a screening parameter for primary aldosteronism). Their adrenal Cyp11b2 (aldosterone synthase) expression was increased and remained elevated on a high-salt diet (relative autonomy, characteristic of primary aldosteronism), but plasma aldosterone was only elevated in male animals. The systolic blood pressure of Cacna1hM1560V/+ mice was 8 mmHg higher than in wild-type littermates and remained elevated on a high-salt diet. Cacna1h-/- mice had elevated renal Ren1 (renin-1) expression but normal adrenal Cyp11b2 levels, suggesting that in the absence of CaV3.2, stimulation of the renin-angiotensin system activates alternative calcium entry pathways to maintain normal aldosterone production. On a cellular level, Cacna1hM1560V/+ adrenal slices showed increased baseline and peak intracellular calcium concentrations in the zona glomerulosa compared to controls, but the frequency of calcium spikes did not rise. We conclude that FH-IV, on a molecular level, is caused by elevated intracellular Ca2+ concentrations as a signal for aldosterone production in adrenal glomerulosa cells. We demonstrate that a germline Cacna1h gain-of-function mutation is sufficient to cause mild primary aldosteronism, whereas loss of CaV3.2 channel function can be compensated for in a chronic setting.

Epigenetic Regulation of the Renin-Angiotensin-Aldosterone System in Hypertension.

Activation of the renin-angiotensin-aldosterone system (RAAS) plays an important pathophysiological role in hypertension. Increased mRNA levels of the angiotensinogen angiotensin-converting enzyme, angiotensin type 1 receptor gene, Agtr1a, and the aldosterone synthase gene, CYP11B2, have been reported in the heart, blood vessels, and kidneys in salt-sensitive hypertension. However, the mechanism of gene regulation in each component of the RAAS in cardiovascular and renal tissues is unclear. Epigenetic mechanisms, which are important for regulating gene expression, include DNA methylation, histone post-translational modifications, and microRNA (miRNA) regulation. A close association exists between low DNA methylation at CEBP-binding sites and increased AGT expression in visceral adipose tissue and the heart of salt-sensitive hypertensive rats. Several miRNAs influence AGT expression and are associated with cardiovascular diseases. Expression of both ACE and ACE2 genes is regulated by DNA methylation, histone modifications, and miRNAs. Expression of both angiotensinogen and CYP11B2 is reversibly regulated by epigenetic modifications and is related to salt-sensitive hypertension. The mineralocorticoid receptor (MR) exists in cardiovascular and renal tissues, in which many miRNAs influence expression and contribute to the pathogenesis of hypertension. Expression of the 11beta-hydroxysteroid dehydrogenase type 2 (HSD11B2) gene is also regulated by methylation and miRNAs. Epigenetic regulation of renal and vascular HSD11B2 is an important pathogenetic mechanism for salt-sensitive hypertension.

Expression and significance of CEMIP and CYP11B2 in serum in women with foetal growth restriction.

BACKGROUND: Foetal growth restriction (FGR) occurs when a foetus fails to reach its growth potential. This observational study assessed the expression and significance of cell migration-including protein (CEMIP) and aldosterone synthase (CYP11B2) in the serum of pregnant women with FGR. METHODS: 40 singleton FGR-suffered pregnant women, as well as 40 normal singleton pregnant women, were enrolled. The expression of CEMIP and CYP11B2 in serum was detected in early pregnancy. The correlations between parameters were evaluated. The predictive variables for FGR were determined. The diagnostic value of CEMIP and CYP11B2 for FGR was analysed. RESULTS: CEMIP and CYP11B2 mRNA expression in the serum of pregnant women with FGR decreased (both P < 0.001). CEMIP (95%CI: 0.802-0.921, P < 0.001) and CYP11B2 (95%CI: 0.795-0.907, P < 0.001) mRNA expression in serum and soluble fms like tyrosine kinase-1 (sFLT1)/placental growth factor (PlGF) ratio (95%CI: 0.866-0.974, P < 0.001) were independent predictors of FGR, and CEMIP (r = -0.578, P = 0.001) and CYP11B2 (r = -0.602, P < 0.001) mRNA expression in serum were negatively correlated with sFLT1/PlGF ratio. CEMIP (AUC = 0.741) and CYP11B2 (AUC = 0.764) mRNA expression in serum had good diagnostic value for FGR. CONCLUSION: The expression of CEMIP and CYP11B2 is reduced in the serum of pregnant women with FGR and may become new diagnostic markers for FGR.

Foetal growth restriction is the inability of the foetus to reach its growth potential in the uterus due to various factors. This study aimed to investigate the expression and significance of cell migration-including protein and aldosterone synthase in serum of pregnant women with foetal growth restriction. In our study, we found that the expression of cell migration-including protein and aldosterone synthase in serum of pregnant women with foetal growth restriction were decreased. Cell migration-including protein and aldosterone synthase expression was negatively correlated with soluble fms like tyrosine kinase-1/placental growth factor ratio. In addition, the study also found that cell migration-including protein and aldosterone synthase expression in serum had good diagnostic value for foetal growth restriction.

Node-by-node diagnosis for multiple ipsilateral nodules by segmental adrenal venous sampling in primary aldosteronism.

OBJECTIVES: In patients with primary aldosteronism (PA), multiple adrenocortical nodules may be present on the surgical side. The aim of this study was to clarify the pathological diagnosis and the node-by-node diagnostic capability of segmental adrenal venous sampling (sAVS). DESIGN: Retrospective study. PATIENTS: A total of 162 patients who underwent adrenalectomy following sAVS were studied. MEASUREMENTS: Multiple nodules on the surgical side were extracted while referring to contrast-enhanced computed tomography images. We also performed a detailed histopathological analysis of the resected specimens from patients undergoing sAVS, which included immunohistochemistry for CYP11B2. RESULTS: In 11 (6.8%) patients, two to three nodules were detected on the surgical side. All patients were diagnosed by sAVS with at least one aldosterone-producing adenoma (APA) for localized aldosterone elevation in tributaries. Seven patients showed a lateralization index value of ≥4 after ACTH stimulation. Histopathologically and clinically, two patients had two or three CYP11B2-positive APAs, and the other nine patients both APAs and non-APAs. The positive predictive value of the most suspected APA, that is, the drainer that showed the highest aldosterone level by sAVS, was 11/11 (100%, 95% confidence interval [CI]: 71.5%-100%), while that for the second and third suspected APA was 3/7 (42.9%, 95% CI: 9.9%-81.6%), and they were significantly different (p = .01). Further, the positive predictive value of non-APA was 4/4 (100%, 95% CI: 39.8%-100%). CONCLUSIONS: The sAVS could correctly diagnose the aldosterone production in multiple ipsilateral adrenal nodules.

High-throughput screening of cytochrome P450 (CYP) family of genes in primary and recurrent pterygium.

Pterygium is a common degenerative disease characterized by fibrovascular outgrowth towards cornea. Around 200 million people have been reported to be affected by the pterygium in the world. Although the risk factors for pterygium are well documented, the molecular pathogenesis of pterygium seems to be very complex and remains highly elusive. However, the common sense for the development of pterygium appears to be deregulation of growth hemostasis due to aberrant apoptosis. In addition, pterygium shares many features with human cancers, including dysregulation of apoptosis, persistent proliferation, inflammation, invasion, and relapse following resection. Cytochrome P450 (CYP) monooxygenases are a superfamily of heme-containing enzymes with a wide range of structural and functional diversity. In the present study, we aimed to identify significant expression signatures of CYP gene in pterygium. For the study, a total number of 45 patients (30 primary and 15 recurrent pterygium) were included. For the high-throughput screening of CYP gene expression, Fluidigm 96.96 Dynamic Array Expression Chip was used and analyzed with BioMark™ HD System Real-Time PCR system. Remarkably, CYP genes were identified to be significantly overexpressed in both primary and recurrent pterygium samples. Most prominent overexpression was observed in CYP1A1, CYP11B2 and CYP4F2 in primary pterygium and CYP11A1 and CYP11B2 in recurrent pterygium. Consequently, present findings suggest the significant involvement of CYP genes in the development and progression of pterygium.

Functional nodules in primary aldosteronism: identification of CXCR4 expression with 68Ga-pentixafor PET/CT.

OBJECTIVES: We analyzed the diagnostic efficiency of 68Ga-pentixafor PET/CT for functional nodules in primary aldosteronism (PA). Furthermore, we compared the correlation of CXCR4 expression with aldosterone synthase (CYP11B2) expression and PET/CT uptake in these patients. METHODS: We prospectively assessed 50 patients diagnosed with PA and 10 patients with non-functional adrenal adenoma (NFA). All patients underwent 68Ga-pentixafor PET/CT before adrenalectomy. Immunohistochemistry (IHC) was performed to detect the protein expression of CYP11B2 and the G-protein-coupled receptor CXCR4. RESULTS: CYP11B2 IHC revealed the presence of 43 functional nodules. Subsequently, 40/43 functional nodules could be detected on 68Ga-pentixafor PET/CT, while negative imaging findings were noted for 11/13 non-functional nodules (sensitivity, 93.0%; specificity, 84.6%). The optimum SUVmax cut-off for the identification of functional nodules was 8.95 (AUC 0.914 [0.828-1.000], p < 0.001). Regarding the size of functional nodules, diagnostic efficiency appeared to be much higher for nodules greater than 1 cm in size (sensitivity, up to 97.3%). Moreover, we examined the relationship between CXCR4 and CYP11B2 expression in 56 lesions. All 43 CYP11B2-positive nodules were CXCR4-positive, but one of the 13 CYP11B2-negative nodules (7.7%) showed false-positive staining for CXCR4. Moreover, the consistency between PET/CT uptake and CXCR4 staining results was 92.9% (52/56). CONCLUSIONS: At least 90% of functional nodules show positive uptake on 68Ga-pentixafor PET/CT, and the detection ability is much better for nodules with a diameter ≥ 1 cm. With its high sensitivity and specificity, 68Ga-pentixafor PET/CT can be considered a promising surgical decision-making tool for patients with PA. KEY POINTS: • 68Ga-pentixafor PET/CT could be a useful tool for the identification of functional adrenal nodules in APAs and even IHAs. • The diagnostic efficiency appears to be much higher for nodules ≥ 1 cm in size. • There is high consistency between the results of 68Ga-pentixafor PET/CT imaging and CXCR4 immunohistochemistry.

CYP11B2 inhibitor dexfadrostat phosphate suppresses the aldosterone-to-renin ratio, an indicator of sodium retention, in healthy volunteers.

AIMS: High aldosterone is a key driver of hypertension and long-term negative sequelae. We evaluated the safety and efficacy of dexfadrostat phosphate (DP13), a novel aldosterone synthase (CYP11B2) inhibitor, in healthy participants. METHODS: This randomized, double-blind, placebo-controlled study was conducted in two parts. In part A, a single-ascending dose escalation, 16 participants received oral DP13 1-16 mg. Part B was a multiple-ascending dose, sequential group study in which 32 participants received oral DP13 4, 8 or 16 mg once daily for 8 days. Safety and tolerability were monitored throughout. An adrenocorticotropic hormone (ACTH) stimulation test at maximal blood drug concentrations defined the dose range for multiple dosing. RESULTS: DP13 was well tolerated at all doses, with no serious adverse events. In part B, all DP13 doses (4, 8 and 16 mg) over 8 days effectively suppressed aldosterone production, increased the urinary sodium/potassium ratio, decreased plasma sodium and increased plasma potassium and renin levels compared with placebo, resulting in potent suppression of the aldosterone-to-renin ratio (ARR). Endocrine counter-regulation resulted in the 4 mg dose no longer sustaining 24-h aldosterone suppression after 8 days of treatment, unlike the 8- and 16 mg doses. There was no evidence of drug-induced adrenal insufficiency (ACTH stress challenge). CONCLUSIONS: In patients with excess aldosterone and ensuing sodium retention driving hypertension, managing sodium balance is critical. A CYP11B2 inhibitor like DP13, whose effectiveness can be monitored by a reduction in ARR, may prove valuable in managing aldosterone-dependent hypertension and primary aldosteronism.

Fluorinated aldosterone synthase (CYP11B2)-inhibitors for differential diagnosis between bilateral and unilateral conditions of primary aldosteronism.

The enzyme aldosterone synthase (CYP11B2) is specifically expressed in aldosterone-producing tissue of the adrenal cortex and is overexpressed in aldosterone-producing adenomas (APA). It therefore represents an ideal target for molecular imaging, particularly for the differential diagnosis between bilateral hyperplasia and unilateral APA in primary aldosteronism. However, the presence of the cortisol-producing enzyme 11ß-hydroxylase (CYP11B1) in the adrenal cortex remains very challenging owing to its high homology to CYP11B2. Within this study, we efficiently synthesized a variety of disubstituted fluorinated pyridines and pyrazines by Suzuki coupling reactions. These compounds were evaluated for their ability to inhibit CYP11B1 and CYP11B2 in transfected Y1 cells and in NCI-h295 cells. Several compounds were found to exhibit excellent affinity (IC50 < 10 nM) to CYP11B2 as well as strong selectivity (up to 125-fold) over CYP11B1. These findings support the further development of an analogous 18F-labelled PET tracer.

Unexpectedly high mutation rate of cyp11b1 compared to cyp21a2 in randomly-selected turkish women: a large screening study.

PURPOSE: Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders resulting from enzyme deficiencies associated with steroidogenesis. The clinical presentation of non-classic CAH (NCAH) in females is often indistinguishable from other hyperandrogenic disorders like polycystic ovary syndrome (PCOS). The data on the prevalence of NCAH in unselected women in the literature is scanty. The research aimed to evaluate the prevalence of NCAH, carrier frequencies, and the correlation between clinical symptoms and genotype in Turkish women. METHODS: The study group comprised two hundred and seventy randomly-selected unrelated asymptomatic women of reproductive age (18-45). Subjects were recruited from female blood donors. All volunteers underwent clinical examination and hormone measurements. The protein-encoding exons and exon-intron boundaries of the CYP21A2, CYP11B1, HSD3ß2 and CYP21A2 promoter were sequenced by direct DNA sequencing. RESULTS: After genotyping, seven (2.2%) individuals were diagnosed with NCAH. The heterozygous carrier frequencies of CYP21A2, CYP21A2 promoter, CYP11B1, and HSD3ß2 genes with 34, 34, 41, and 1 pathologic mutation were determined at 12.6%, 12.6%, 15.2%, and 0.37% of volunteers, respectively. Gene-conversion (GC) frequencies between CYP21A2/CYP21A1P and CYP11B1/CYP11B2 were determined as 10.4% and 14.8%, respectively. CONCLUSION: Despite GC-derived higher mutation frequency determined in the CYP11B1 gene, the reason for the low frequency of NCAH due to 11OHD compared to 21OHD might be that gene-conversion arises with active CYP11B2 rather than an inactive pseudogene. HSD3ß1 exhibits high homology with HSD3ß2 located on the same chromosome; remarkably, it demonstrates low heterozygosity and no GC, most probably the outcome of a tissue-specific expression pattern.

Pathology and gene mutations of aldosterone-producing lesions.

The human adrenal cortex secretes aldosterone and cortisol as major corticosteroids. For their production, CYP11B2 and CYP11B1 catalyze the last steps in the syntheses of aldosterone and cortisol, respectively. In our previous study, CYP11B2 was the first successfully purified from rat adrenals and human clinical samples and then was proved to be aldosterone synthase. We demonstrated the immunohistochemistry for CYP11B2 of both rats and humans and applied it clinically to visualize the functional histology of aldosterone-producing adenoma (APA) causing primary aldosteronism (PA). We discovered aldosterone-producing cell clusters (APCCs) and possible APCC-to-APA transitional lesions (pAATLs) and further visualized aldosterone-producing lesions for rare forms of PA including familial hyperaldosteronism type 3 and novel non-familial juvenile PA. Here we review the history of our research on aldosterone-producing lesions.

Aldosterone Synthase Inhibition With Lorundrostat for Uncontrolled Hypertension: The Target-HTN Randomized Clinical Trial.

Importance: Excess aldosterone production contributes to hypertension in both classical hyperaldosteronism and obesity-associated hypertension. Therapies that reduce aldosterone synthesis may lower blood pressure. Objective: To compare the safety and efficacy of lorundrostat, an aldosterone synthase inhibitor, with placebo, and characterize dose-dependent safety and efficacy to inform dose selection in future trials. Design, Setting, and Participants: Randomized, placebo-controlled, dose-ranging trial among adults with uncontrolled hypertension taking 2 or more antihypertensive medications. An initial cohort of 163 participants with suppressed plasma renin (plasma renin activity [PRA] ≤1.0 ng/mL/h) and elevated plasma aldosterone (≥1.0 ng/dL) were enrolled, with subsequent enrollment of 37 participants with PRA greater than 1.0 ng/mL/h. Interventions: Participants were randomized to placebo or 1 of 5 dosages of lorundrostat in the initial cohort (12.5 mg, 50 mg, or 100 mg once daily or 12.5 mg or 25 mg twice daily). In the second cohort, participants were randomized in a 1:6 ratio to placebo or lorundrostat, 100 mg once daily. Main Outcomes and Measures: The primary end point was change in automated office systolic blood pressure from baseline to study week 8. Results: Between July 2021 and June 2022, 200 participants were randomized, with final follow-up in September 2022. Following 8 weeks of treatment in participants with suppressed PRA, changes in office systolic blood pressure of -14.1, -13.2, -6.9, and -4.1 mm Hg were observed with 100 mg, 50 mg, and 12.5 mg once daily of lorundrostat and placebo, respectively. Observed reductions in systolic blood pressure in individuals receiving twice-daily doses of 25 mg and 12.5 mg of lorundrostat were -10.1 and -13.8 mm Hg, respectively. The least-squares mean difference between placebo and treatment in systolic blood pressure was -9.6 mm Hg (90% CI, -15.8 to -3.4 mm Hg; P = .01) for the 50-mg once-daily dose and -7.8 mm Hg (90% CI, -14.1 to -1.5 mm Hg; P = .04) for 100 mg daily. Among participants without suppressed PRA, 100 mg once daily of lorundrostat decreased systolic blood pressure by 11.4 mm Hg (SD, 2.5 mm Hg), which was similar to blood pressure reduction among participants with suppressed PRA receiving the same dose. Six participants had increases in serum potassium above 6.0 mmol/L that corrected with dose reduction or drug discontinuation. No instances of cortisol insufficiency occurred. Conclusions and Relevance: Among individuals with uncontrolled hypertension, use of lorundrostat was effective at lowering blood pressure compared with placebo, which will require further confirmatory studies. Trial Registration: ClinicalTrials.gov Identifier: NCT05001945.