Five patients with 11β-hydroxylase deficiency due to CYP11B1 gene mutation: A case study / 中华内分泌代谢杂志

Objective:To investigate the clinical and molecular characteristics of 11β-hydroxylase deficiency(11β-OHD) to improve the understanding of this disorder.Methods:The clinical manifestation, hormone level, imaging examination, characteristics of gene variation and follow-up of five patients with 11β-OHD diagnosed in Henan Children′s Hospital from 2016 to 2021 were carefully reviewed.Results:Among the 5 children, 3 were male and 2 were female, all without positive family history. The age at diagnosis was 1 year 5 months to 7 years(average 3 years and 9 months), and the bone age was 3 years 6 months to 16 years(average 10 years and 3 months). Two cases were misdiagnosed as 21-hydroxylase deficiency(21-OHD) and treated with long-term mineralocorticoids. Three patients presented with hypertension and one patient had testicular adrenal rest tumor. Adrenal CT showed bilateral adrenal hyperplasia in five patients. ACTH, 17-hydroxyprogesterone, testosterone, and androstenedione levels were increased in 5 children, and hypokalemia occurred in 1 patient. One patient carried homozygous novel missense variant, and four patients had compound heterozygous variants. Four patients carried missence mutations, two patients had deletion and one patient harbored a chimeric CYP11B2 exon1-6/CYP11B1 exon7-9. Three novel CYP11B1 mutations, including c. 1385T>C(p.L462P), c.64C>T(p.Q22*)and c. 1354G>A(p.G452R) were identified. The final height of 2 male children were 164.4 cm and 150.2 cm, respectively, and the related hormone levels of the other 3 children were normal.Conclusion:11β-OHD is easily misdiagnosed, leading to severe impairment of final height. CYP11B1 gene variation is complex and diverse, which requires variety of gene detection methods.

New insights on aldosterone-producing cell clusters in the pathogenesis of primary aldosteronism / 中华内分泌代谢杂志

Primary aldosteronism(PA) is one of the most common secondary hypertension, the pathogenesis is still not fully understood. Aldosterone synthase(CYP11B2) was thought to be continuously expressed in the zona glomerulosa of the adrenal cortex. In recent years, it is found that there were discontinuous CYP11B2 positive cell clusters in adrenal cortex via immunohistochemical staining, and proposed the concept of aldosterone-producing cell clusters(APCC). Thenceforwarding a growing body of studies suggest that there may be a potential causal link between APCC and PA. This article summarizes the latest studies on APCC and provide an update on the potential role of APCC in the pathogenesis of PA.

Atractylenolide-I covalently binds to CYP11B2, selectively inhibits aldosterone synthesis, and improves hyperaldosteronism

Hyperaldosteronism is a common disease that is closely related to endocrine hypertension and other cardiovascular diseases. Cytochrome P450 11B2 (CYP11B2), an important enzyme in aldosterone (ALD) synthesis, is a promising target for the treatment of hyperaldosteronism. However, selective inhibitors targeting CYP11B2 are still lacking due to the high similarity with CYP11B1. In this study, atractylenolide-I (AT-I) was found to significantly reduce the production of ALD but had no effect on cortisol synthesis, which is catalyzed by CYP11B1. Chemical biology studies revealed that due to the presence of Ala320, AT-I is selectively bound to the catalytic pocket of CYP11B2, and the C8/C9 double bond of AT-I can be epoxidized, which then undergoes nucleophilic addition with the sulfhydryl group of Cys450 in CYP11B2. The covalent binding of AT-I disrupts the interaction between heme and CYP11B2 and inactivates CYP11B2, leading to the suppression of ALD synthesis; AT-I shows a significant therapeutic effect for improving hyperaldosteronism.

Testosterona inhibe la actividad de la aldosterona sintasa silvestre y quimérica in vitro

Background: Familial hyperaldosteronism type I is caused by the generation of a chimeric aldosterone synthase enzyme (ASCE) which is regulated by ACTH instead of angiotensin II. We have reported that in vitro, the wild-type (ASWT) and chimeric aldosterone synthase (ASCE) enzymes are inhibited by progesterone and estradiol does not affect their activity. Aim: To explore the direct action of testosterone on ASWT and ASCE enzymes. Material and Methods: HEK-293 cells were transiently transfected with vectors containing the full ASWT or ASCE cDNAs. The effect of testosterone on AS enzyme activities was evaluated incubating HEK-cells transfected with enzyme vectors and adding deoxycorticosterone (DOC) alone or DOC plus increasing doses of testosterone. Aldosterone production was measured by HPLC-MS/MS. Docking of testosterone within the active sites of both enzymes was performed by modelling in silico. Results: In this system, testosterone inhibited ASWT (90% inhibition at five pM, 50% inhibitory concentration (IC50) =1.690 pM) with higher efficacy andpotency than ASCE (80% inhibition at five pM, IC50=3.176 pM). Molecular modelling studies showed different orientation of testosterone in ASWT and ASCE crystal structures. Conclusions: The inhibitory effect of testosterone on ASWT or ASCE enzymes is a novel non-genomic testosterone action, suggesting that further clinical studies are needed to assess the role of testosterone in the screening and diagnosis of primary aldosteronism.

ACTHR in regulating aldosterone secretion to angiotensin Ⅱ and potassium chloride stimulation / 中华内分泌外科杂志

Objective To study CYP11B2 mRNA and aldosterone secretion alteration in human adrenocortical carcinoma H295R cell after angiotensin Ⅱ (AT-Ⅱ) and potassium chloride stimulation,and to investigate the effect of adrenocorticotropic hormone receptor (ACTHR) on them.Methods Lentiviral vector was used to increase ACTHR expression.It was transfected into the H295R cells.Similarly,another H295R cells,without ACTHR vector,was used as the control group.ACTHR alteration was measured by Western blot and real-time polymerase chain reaction (RT-PCR).CYP11B2 mRNA was detected at 24 hours after 100 nmol/L AT-Ⅱ/16 mmol/L KCL stimulation,and the amplification of the two groups was compared.Aldosterone was measured by ELISA kit.Results Compared with those in control ceils,the protein and mRNA level of ACTHR in experimental cells were increased 2.4 times and 18 times respectively (P＜0.05).CYP11B2 mRNA of experimental cells was 1.7 times higher than control cells after 24 h stimulation of AT-Ⅱ.Aldosterone production was 121.98+8.31 and 104.05+6.88 ng/L respectively.The former amplification was 2.06 times higher than that of the latter (P＜0.05).Similarly,CYP11B2 mRNA of experimental cells was 19.2 times higher than control cells after 24 h stimulation of KCL.Aldosterone production was 137.67±10.35 and 104.05 ± 6.88 ng/L respectively.The former amplification was 3.13 times higher than that of the latter (P＜0.05).Conclusion Overexpression of ACTHR increases the sensitivity and response of CYP11B2 mRNA and aldosterone to AT-Ⅱ and KCL stimulation,and ACTHR is expected to become a key protein in understanding primary aldosteronism.

CYP11B2 gene polymorphism among coronary heart disease patients and blood donors in Malaysia

Various previous studies have reported the implication of CYP11B2 gene polymorphism in the pathophysiology of cardiovascular diseases. In particular, the -344T/C polymorphism, which is located at a putative binding site for the steroidogenic transcription factor (SF-1) has been associated with essential hypertension, left ventricular dilation and coronary heart disease. In the present study, we aim to determine the allele and genotype frequencies of the CYP11B2 gene in patients with clinical manifestation of coronary heart disease and confirmed by angiography and blood donors and to calculate the association of the gene polymorphism with CHD. A total of 79 DNA from patients with coronary heart disease admitted to the National Heart Institute and 84 healthy blood donors have been genotyped using polymerase chain reaction technique followed by restriction enzyme digestion (RFLP). Results of the study demonstrated that out of 79 for the patients, 40 were homozygous T, 10 were homozygous C and 29 were heterozygous TC. The frequencies of genotype TT, CC and TC for patients were 0.5, 0.13 and 0.36 respectively. The frequencies of allele T and C in patients were 0.68 and 0.31 respectively. While for the blood donors, 40 subjects were of homozygous T, 7 were homozygous C and 37 were heterozygous TC. The genotype frequencies for the TT, CC and TC were 0.47, 0.08 and 0.44 respectively. The frequency of the allele T was 0.69 and allele C was 0.3. Chi-Square analysis showed that there was no significant difference in the genotype and C allele frequencies between the CHD patients and the blood donors. Our study suggests that there is lack of association between -344T/C polymorphism of CYP11B2 gene and coronary heart disease.

Meta analysis of the association between CYP11 B2 gene polymorphism and left ventricle hypertrophy / 中华胸心血管外科杂志

Objective To investigate the association between CYP11 B2 gene polymo-rphism and left ventricle hypertrophy with meta analysis.Methods Literatures about the association of CYP11 B2 gene polymorphism and left ventricle hypertrophy from January 1992 to December 2011 were searched.The electronic databases retrieved from Pubmed,Embase,China national knowledge intemet,Chinese biological medicine disk,VIP fulltext database and Wanfang fulltext database.Odds ratio of CYP11 B2 genotype distributions in left ventricle hypertrophy patients comparing with healthy control were analyzed.RevMan5.1 software was applied for investigating hereogeneity among individual studies and summarizing effects with proper statistical methods.Six case control studies were enrolled.Results A total of 541 cases and 553 controls were enrolled for the study.The pooled OR of CC vs TT + TC genotype was 1.15 (95％ CI:0.74 ～ 1.80) (Z =0.63,P =0.53) in the subgroup of hypertension,and the pooled OR of CC vs TT + TC genotype was 1.15 (95 ％ CI:0.74 ～ 1.80) (Z =0.63,P =0.53) in the subgroup of race.The pooled OR of C vs T allele was 1.15 (95％ CI:0.76 ～ 1.74) vs 0.87 (95％ CI:0.58 ～ 1.31) (Z =0.67,P =O.50).Conclusion Whether the hypertension or the race,the genotype of CYP11 B2 polymorphism has no association with an increased risk of left ventricle hypertrophy.

Association of aldosterone synthase (CYP11B2 C-344T) gene polymorphism & susceptibility to essential hypertension in a south Indian Tamil population.

Background & objective: Renin-angiotensin aldosterone system (RAAS) plays an important role in the regulation of blood pressure. Aldosterone, synthesized by aldosterone synthase in the adrenal cortex is encoded by the CYP11B2 gene. In this case-control study we examined the association between CYP11B2 C-344T polymorphism and essential hypertension in south Indian Tamil population. Methods: The study was conducted in 406 hypertensive cases and 424 healthy controls from Tamil population. Genotyping was performed by PCR-restriction fragment length polymorphism method. Statistical analysis was performed by logistic regression analysis. Results: The 344TT homozygous variant genotype (OR-1.8; 95% CI: 1.1-2.8; P=0.02) and T allele (P=0.007) were found to be significantly associated with hypertension. In gender based analysis, the risk was significantly higher in male hypertensives (OR-1.8; 95% CI: 1.0-3.6, P=0.05) but not in female subjects. Interpretation & conclusion: A significant association between CYP11B2 gene polymorphism and essential hypertension was observed and the risk was confined to male subjects in south Indian Tamil population.

Impact of gene-environment interaction between the C (-344) T polymorphism of CYP11B2 and drinking index on the risk of hypertension under multifactor dimensionality reduction model in Chinese Mongolian population / 中华流行病学杂志

1.22-4.56), 2.05(1.07-3.94) and 5.56(2.54-12.18) respectively. Conclusion Essential hypertension might positively be affected by the interaction of the C (-344) T polymorphism of CYP11B2 and the drinking index in Chinese Mongolian population.

Associations of the genetic polymorphisms in CYP11B2 gene with nonfamilial structural atrial fibrillation / 中华流行病学杂志

Objective To investigate whether polymorphisms in CYP11B2 gene are associated with nonfamilial structural atrial fibrillation(AF) in Chinese Han population. Methods A free-designed pair-matched hospital based ease-control study was performed in 297 cases and 297 controls. We investigated two tagging single nucleotide polymorphisms (tSNPs)-rs4545, rs3802228 in CYP11B2 gene by using GenomeLab~(TM) SNPstream technique. Results Two tSNPs were consistent with Hardy-Weinberg expectations in case and control groups. Compared with controls, the left atrial diameter of cases was significantly higher(P<0.0001). No significant difference in genotype or allele frequencies of tSNPs in CYP11B2 gene was observed. However, at the site of rs3802228 in 3' UTR of the case group, the left atrial diameter in AF patients with GG genotype was significantly higher than others. After adjusted for covariates age, smoking, Body mass index and hypertension, we did not observe the association of rs4545, rs3802228 with AE Conclusion Our result suggested that polymorphisms of rs4545 in CYP11B2 gene might not be associated with atrial fibrillation but polymorphism of 3' UTR rs3802228 locus in CYP11B2 gone might be associated with atrial structural remodeling.

Interaction of Pituitary Adenylate Cyclase-Activating Polypeptide and Angiotensin II on Aldosterone Production in Human Adrenocortical H295R Cells / 대한내분비학회지

BACKGROUND: Evidence is accumulating that aldosterone secretion can be regulated in a paracrine and/or an autocrine manner by several neuropeptides locally released within the adrenal gland. Among neuropeptides, pituitary adenylate cyclase-activating polypeptide (PACAP) is present in high concentration in the human adrenal gland. The purpose of this study was to investigate the action of PACAP and the interaction between PACAP and angiotensin II (AII), the main physiologic aldosterone secretagogue, in aldosterone production in human H295R adrenocortical cells. METHODS: H295R cells were incubated with increasing concentrations of PACAP (10(-11)M~10(-7)M) in the absence or presence of 10(-7)M AII. Aldosterone concentration in the supernatant was determined by RIA. Intracellular cAMP content was measured by RIA and total inositol phosphate (IP) production by anion exchange chromatography. Gene expression of CYP11B2 was studied by RT-PCR. RESULTS: In H295R cells, PACAP stimulated aldosterone production in a dose-dependent manner. Incubation of H295R cells with PACAP in the presence of AII significantly increased aldosterone production, compared with that of PACAP alone. PACAP dose-dependently increased cAMP production, but 10(-7)M AII had no effect on either basal or PACAP-stimulated cAMP production. Total IP production was not affected by PACAP, but was increased by 10(-7)M AII; an increase that was not further increased by addition of PACAP. RT-PCR analysis of H295R cells which were exposed to 10-7M PACAP or 10(-7)M AII showed an increase in CYP11B2 transcript signal. Induction of CYP11B2 mRNA expression in response to treatment with both PACAP and AII was significantly more than that resulting from using PACAP alone. CONCLUSION: The present study demonstrates that PACAP exerts a direct stimulatory effect on aldosterone production through induction of CYP11B2 mRNA expression by adenylate cyclase activation as the main intracellular signal pathway in H295R cells. Furthermore, there may be some additive effects between PACAP and AII on aldosterone production.

The Effects of an Aldosterone Synthase (CYP11B2) Gene Polymorphism on the Risk of Myocardial Infarction

BACKGROUND AND OBJECTIVES: Several polymorphisms of the renin-angiotensin-aldosterone system have been found to have pleiotropic effects on cardiovascular diseases. Polymorphism of the aldosterone synthase gene (CYP11B2), which may influence plasma aldosterone levels, has been reported to cause systemic hypertension, influence the left ventricular diameter and mass, and decrease baroreflex sensitivity of the cardiovascular system. Through these mechanisms, it is thought to increase the risk of myocardial infarction (MI). Our study was designed to elucidate whether polymorphism of CYP11B2 increased the risk of MI. SUBJECTS AND METHODS: We analyzed the genotypes of CYP11B2 and the classic risk factors of MI in 188 MI patients and 320 control subjects without history of MI. RESULTS: There was no significant difference in the distribution of genotypes between the patient and control groups. Adjusting for the classical risk factors, multiple logistic regression analysis showed no significant effect of CYP11B2 gene polymorphism on the development of MI. However, the presence of the -344C allele is associated with a markedly increased MI risk conferred by classic risk factors including hypertension, smoking, and male sex. In particular, hypertension was not a significant risk factor as compared with non-hypertensive patients in subjects without -344C, but the relative risk was increased to 2.40 (95% CI:1.05-5.51, p<0.05) with - 344C. The relative risks of smoking and male sex were also increased with the presence of the - 344C allele. CONCLUSION: CYP11B2 polymorphism is not an independent risk factor of MI, although hypertension, smoking, and male sex are more potent risk factors for MI in Koreans who possess the - 344C allele.