Search

Most aldosterone-producing adenomas (APAs) have gain-of-function somatic mutations of ion channels or transporters. However, their frequency in aldosterone-producing cell clusters of normal adrenal gland suggests a requirement for codriver mutations in APAs. Here we identified gain-of-function mutations in both CTNNB1 and GNA11 by whole-exome sequencing of 3/41 APAs. Further sequencing of known CTNNB1-mutant APAs led to a total of 16 of 27 (59%) with a somatic p.Gln209His, p.Gln209Pro or p.Gln209Leu mutation of GNA11 or GNAQ. Solitary GNA11 mutations were found in hyperplastic zona glomerulosa adjacent to double-mutant APAs. Nine of ten patients in our UK/Irish cohort presented in puberty, pregnancy or menopause. Among multiple transcripts upregulated more than tenfold in double-mutant APAs was LHCGR, the receptor for luteinizing or pregnancy hormone (human chorionic gonadotropin). Transfections of adrenocortical cells demonstrated additive effects of GNA11 and CTNNB1 mutations on aldosterone secretion and expression of genes upregulated in double-mutant APAs. In adrenal cortex, GNA11/Q mutations appear clinically silent without a codriver mutation of CTNNB1. Sequence analysis identifies gain-of-function somatic mutations in GNA11 or GNAQ in CTNNB1-mutant aldosterone-producing adenomas. Most patients with these mutations presented during puberty, pregnancy or menopause, with elevated LHCGR expression.

Background: We report (this meeting) somatic mutation of GNA11/Q in CTNNB1-mutant APAs. The recurrent co-driver mutation causes reversible hypertension in puberty, pregnancy, or menopause. We have investigated the molecular mechanism of this association. Methods: Gene expression profiles in 3 double mutant APAs were studied by unsupervised hierarchical clustering analysis and enrichment analysis of 362 differentially expressed genes and validated by qPCR, IFC and IHC in 10 double mutant APAs or transfected primary adrenal cells. Multiple region biopsies were performed in 7 adrenals adjacent to double-mutant APAs and 4 APAs with KCNJ5 or CACNA1D mutations. The findings of APA mutations in adjacent adrenals were replicated in each case by ddPCR ± NGS. Results: Unsupervised hierarchical clustering analysis showed clustering of the double-mutant APAs, and a high proportion of genes were many-fold upregulated compared to other APAs. LHCGR, TMEM132E, DKK1, C9orf84, FAP, GNRHR and MPP3 are among the genes with high expression. A small number of genes are down-regulated in the double-mutant APAs, including CYP11B1. qPCR confirmed an average of ~10 to 1000-fold higher expression of the hallmark genes in double-mutants. Enrichment analysis showed significant enrichment of features or terms concerned with cell junction and cell adhesion (P

Aldosterone-producing adenomas (APAs) vary in phenotype and genotype. Zona glomerulosa (ZG)-like APAs frequently have mutations of an L-type calcium channel (LTCC) CaV1.3. Using a novel antagonist of CaV1.3, compound 8, we investigated the role of CaV1.3 on steroidogenesis in the human adrenocortical cell line, H295R and in primary human adrenal cells. This investigational drug was compared with the common antihypertensive drug nifedipine, which has 4.5-fold selectivity for the vascular LTCC, CaV1.2, over CaV1.3. In H295R cells transfected with wild-type or mutant CaV1.3 channels, the latter produced more aldosterone than wild-type, which was ameliorated by 100 μM of compound 8. In primary adrenal and non-transfected H295R cells, compound 8 decreased aldosterone production similar to high concentration of nifedipine (100 μM). Selective CaV1.3 blockade may offer a novel way of treating primary hyperaldosteronism, which avoids the vascular side effects of CaV1.2-blockade and provides targeted treatment for ZG-like APAs with mutations of CaV1.3.

Recent discoveries of somatic mutations permit the recognition of subtypes of aldosterone-producing adenomas with distinct clinical presentations and pathological features. Here we describe three women with hyperaldosteronism, two who presented in pregnancy and one who presented after menopause. Their aldosterone-producing adenomas harbored activating mutations of CTNNB1, encoding β-catenin in the Wnt cell-differentiation pathway, and expressed LHCGR and GNRHR, encoding gonadal receptors, at levels that were more than 100 times as high as the levels in other aldosterone-producing adenomas. The mutations stimulate Wnt activation and cause adrenocortical cells to de-differentiate toward their common adrenal-gonadal precursor cell type. (Funded by grants from the National Institute for Health Research Cambridge Biomedical Research Centre and others.).

Background Primary aldosteronism is a curable cause of hypertension if the hypertension is due to an aldosterone-producing adenoma (APA) [1] , [2] . The discovery of somatic mutations defining pathogenetic subtypes of this adenoma has increased recognition of common but small zona glomerulosa-like APAs [3] , [4] , [5] , [6] . In this subtype, we have sought APAs with distinctive presentation or outcome, in which analysis of genotype–phenotype associations could help explain the low success rate and variability of adrenalectomy for curing hypertension. Methods Ten zona glomerulosa-like APAs from three women with primary aldosteronism were analysed by exome sequencing and microarray analysis. Nine had a mutation of ATP1A1 or CACNA1D, and one had a distinctive genotype and transcriptome. Targeted sequencing of further zona glomerulosa-like APAs led to the finding of two with a similar genotype, and to the recognition that all three women presented in early pregnancy or menopause. Quantitative PCR and immunohistochemistry were performed for genes upregulated in the index case. Similar analyses and a TCF–LEF assay for Wnt signalling were performed on cells transfected with the mutant gene. Findings All three APAs had novel mutations in exon 3 of CTNNB1, encoding β-catenin in the Wnt cell-differentiation pathway. The mutations prevented phosphorylation of β-catenin, resulting in an increase in total form of β-catenin and active to total ratio, as quantified by immunoblotting. Transfection of mutant constructs into HEK cells caused near doubling of Wnt signalling in a luciferase reporter assay. Microarray of the index case found a greater than 100-fold increase in expression of gonadal receptors LHCGR and GNRHR, confirmed by qPCR (both genes) and immunohistochemistry (LHCGR) in all three APAs. Increased GATA4 expression was further evidence of adrenocortical cell de-differentiation towards their common gonad-adrenal precursor cell-type. Transfection of LHCGR-negative APA cells with GFP-mutant-CTNNB1 switched on LHCGR expression in GFP-positive cells. Interpretation The role of the Wnt system in adrenal physiology and tumour development is well recognised [7] , [8] . De-differentiation of zona glomerulosa-cells after Wnt activation by the CTNNB1 mutation seems to cause aberrant gonadal receptor expression, which is also previously described [9] , [10] . Our findings connect these observations, and explain the unmasking of small APAs by increases in luteinising hormone and human chorionic gonadotropin hormone in early pregnancy or menopause. Strikingly, all three women, including the treatment-resistant older woman, were clinically cured by adrenalectomy. This contrasts with the failure of adrenalectomy to completely cure hypertension in the majority of patients. This failure is attributable to decades of exposure to aldosterone excess, and the secondary consequences of fibrosis and remodelling in the cardiovascular system [11] , [12] . CTNNB1 mutations have now been reported in 10% of APAs without a previously reported mutation [13] . Elucidation of APA subtypes could, with preoperative genotyping, permit recognition of patients in whom recent onset of primary aldosteronism is likely to be completely resolved by surgery.

Chinese men in Singapore have a higher incidence of hip fractures than Malay and Indian men. We investigated whether there were corresponding ethnic differences in peak bone mineral density (BMD) in young men and whether differences in body composition influenced peak BMD.This was a cross-sectional study of healthy volunteers in a tertiary medical center.A total of 100 Chinese, 82 Malay, and 80 Indian men aged 21 to 40 years, with body mass index between 18 and 30 kg/m(2) underwent dual-energy x-ray absorptiometry to assess BMD, lean mass (LM) and fat mass (FM), and magnetic resonance imaging to quantify abdominal subcutaneous and visceral adipose tissue. Multiple linear regression models, with adjustment for age and height (as a proxy for skeletal size), were used.Malay and Indian men had significantly higher BMD than Chinese men at the lumbar spine (Malay: B, 0.06 ± 0.02, P = .001; Indian: B, 0.03 ± 0.02, P = .049), femoral neck (Malay: B 0.04 ± 0.02, P = .034; Indian: B, 0.04 ± 0.02, P = .041), hip (Malay: B, 0.05 ± 0.02, P = .016; Indian: B, 0.06 ± 0.02, P = .001), and ultradistal radius (Malay: B, 0.03 ± 0.01, P.001; Indian: B, 0.02 ± 0.01, P = .029), and this difference was retained after adjustment for LM and FM, except in Malay men at the femoral neck and in Indian men at the ultradistal radius. LM was an important independent determinant of BMD at all sites, whereas FM, subcutaneous adipose tissue, and visceral adipose tissue were not significantly associated with BMD at any site.Lower peak BMD in Chinese men may partly explain the higher fracture incidence in this ethnic group. Further studies are needed to elucidate the reasons for these ethnic differences in bone accumulation.

Item does not contain fulltext At least 5% of individuals with hypertension have adrenal aldosterone-producing adenomas (APAs). Gain-of-function mutations in KCNJ5 and apparent loss-of-function mutations in ATP1A1 and ATP2A3 were reported to occur in APAs. We find that KCNJ5 mutations are common in APAs resembling cortisol-secreting cells of the adrenal zona fasciculata but are absent in a subset of APAs resembling the aldosterone-secreting cells of the adrenal zona glomerulosa. We performed exome sequencing of ten zona glomerulosa-like APAs and identified nine with somatic mutations in either ATP1A1, encoding the Na(+)/K(+) ATPase alpha1 subunit, or CACNA1D, encoding Cav1.3. The ATP1A1 mutations all caused inward leak currents under physiological conditions, and the CACNA1D mutations induced a shift of voltage-dependent gating to more negative voltages, suppressed inactivation or increased currents. Many APAs with these mutations were

Dear SirThe population of clinical academics in the UK is declining, exacerbated by an ageing workforce: since 2000, the number of full-time equivalent staff has fallen by 12.6%, and the proportion...

Obesity and osteoporosis are two global health problems with pronounced morbidity and mortality. While body weight appears to mitigate the development of osteoporosis, whether excess body fat promotes or protects against osteoporosis remains a conundrum. The effect of ethnicity on these associations has also been understudied. We hypothesize that (1) fat mass (FM) and lean mass (LM) are independently associated with bone mineral density (BMD) and that (2) ethnic differences exist in the association of FM and LM with BMD among Chinese, Malay and Indian subjects.