Expression data from 12 and 52 weeks old Rar-alpha WT and KO male mice
Ontology highlight
ABSTRACT: Primary aldosteronism (PA) is the most frequent form of secondary arterial hypertension. Mutations in different genes increase aldosterone production in PA, but additional mechanisms may contribute to increased cell proliferation and aldosterone producing adenoma (APA) development. We performed transcriptome analysis in APA and identified retinoic acid receptor alpha (RARα) signaling as a central molecular network involved in nodule formation. To understand how RARα modulates adrenal structure and function, we explored the adrenal phenotype of male and female Rarα knockout mice. Inactivation of Rarα in mice led to major structural disorganization of the adrenal cortex in both sexes, with increased adrenal cortex size in female mice and increased cell proliferation in males. Abnormalities of vessel architecture and extracellular matrix were due to decreased Vegfa expression and modifications in extracellular matrix components. On the molecular level, Rarα inactivation leads to inhibition of non-canonical Wnt signaling, without affecting the canonical Wnt pathway nor PKA signaling. Our study suggests that Rarα contributes to the maintenance of normal adrenal cortex structure and cell proliferation, by modulating Wnt signaling. Dysregulation of this interaction may contribute to abnormal cell proliferation, creating a propitious environment for the emergence of specific driver mutations in PA.
Project description:Disorders of isolated mineralocorticoid deficiency causing potentially life-threatening salt-wasting crisis early in life have been associated with gene variants of aldosterone biosynthesis or resistance, but in some patients no such variants are found. WNT/β-catenin signaling is crucial for differentiation and maintenance of the aldosterone producing adrenal zona glomerulosa (zG). We describe a highly consanguineous family with multiple perinatal deaths or infants presenting at birth with failure to thrive, severe salt-wasting crises associated with isolated hypoaldosteronism, nail anomalies, short stature, and deafness. Whole exome sequencing revealed a homozygous splice variant in the R-SPONDIN receptor LGR4 gene (c.618-1G>C) regulating WNT signaling. The resulting transcripts affected protein function and stability, and resulted in loss of Wnt/β-catenin signaling in vitro. The impact of LGR4 inactivation was analyzed by adrenal cortex specific ablation of Lgr4, using Lgr4Flox/Flox mated with Sf1:Cre mice. Inactivation of Lgr4 within the adrenal cortex in the mouse model caused decreased WNT signaling, aberrant zonation with deficient zG and reduced aldosterone production. Thus, human LGR4 mutations establish a direct link between LGR4 inactivation and decreased canonical WNT signaling with abnormal zG differentiation and endocrine function. Therefore, variants in WNT signaling and its regulators should systematically be considered in familial hyperreninemic hypoaldosteronism.
Project description:Primary aldosteronism (PA) is the most common endocrine hypertension comprising 10% of hypertensive patients. A recent series of transcriptome analyses using DNA microarray has shown that neumerous genes are differentially expressed between aldosterone-producing adenoma (APA) and its adjacent adrenal gland (AAG) tissue from the same patient. However, the molecular mechanism(s) of pathogenesis of APA has not yet been fully clarified. Although growing body of evidence has shown that epigenetic abnormalities including DNA methylation play a key role in tumorigenesis, there are few studies with regard to DNA methylation in APA. In the present study, to elucidate the pathogenic relationship between gene expression and DNA methylation in PA, we conducted an integrated analysis of transcriptome and methylome data for paired APA-AAG samples from the same patient. Adrenal specimens were obtained from 7 Japanese patients with APA, who underwent adrenalectomy at Tokyo Medical and Dental University. RNA and DNA samples were extracted from those 7 paired APA and AAG tissues. Gene expression and genome-wide DNA methylation profiles were obtained using SurePrint G3 Human GE 8x60K Microarray (Agilent) and Infinium HumanMethylation450 Beadchip (Illumina), respectively. Transcriptome anlaysis identified 244 significantly (2 fold<) upregulated genes in APA compared to AAG. The upregulated genes include the previously studied genes such as PCP4, ALDH1A2, and CYP11B2, and other genes that have not been previously studied, such as HOXA9, HOXA11, and HOXB9. Gene ontology (GO) analysis for these upregulated genes identified the calcium signaling pathway to be most significantly enriched with the upregulated genes (8 genes). Methylome analysis revealed that APA was globally hypomethylated compared to AAG regardless of gene feature groups, namely, TSS1500, TSS200, 5’UTR, 1stExon, gene body, and 3’UTR. GO analysis for the genes showing hypomethylation at TSS1500/TSS200 regions in APA identified the term “cytokine-cytokine receptor interaction” to be most significantly enriched with hypomethylated genes (37 genes). Integrated analysis of gene expression and genome-wide DNA methylation profiles identified 18 genes that are upregulated and whose TSS1500/TSS200 regions are hypomethylated in APA compared to AAG. These genes include CYP11B2 and MC2R (ACTH receptor). In conclusion, this is the first genome-wide study for PA that integrated transcriptome and methylome data. Global DNA hypomethylation in APA and concordant transcriptional up-regulation of some key genes, such as CYP11B2 and MC2R, may play crucial roles in the pathophysiological significance in PA. Adrenal specimens were obtained from 7 Japanese patients with APA, who underwent adrenalectomy at Tokyo Medical and Dental University. RNA and DNA samples were extracted from those 7 paired APA and AAG tissues. Gene expression and genome-wide DNA methylation profiles were obtained using SurePrint G3 Human GE 8x60K Microarray (Agilent) and Infinium HumanMethylation450 Beadchip (Illumina), respectively.
Project description:Primary aldosteronism (PA) is the most common endocrine hypertension comprising 10% of hypertensive patients. A recent series of transcriptome analyses using DNA microarray has shown that neumerous genes are differentially expressed between aldosterone-producing adenoma (APA) and its adjacent adrenal gland (AAG) tissue from the same patient. However, the molecular mechanism(s) of pathogenesis of APA has not yet been fully clarified. Although growing body of evidence has shown that epigenetic abnormalities including DNA methylation play a key role in tumorigenesis, there are few studies with regard to DNA methylation in APA. In the present study, to elucidate the pathogenic relationship between gene expression and DNA methylation in PA, we conducted an integrated analysis of transcriptome and methylome data for paired APA-AAG samples from the same patient. Adrenal specimens were obtained from 7 Japanese patients with APA, who underwent adrenalectomy at Tokyo Medical and Dental University. RNA and DNA samples were extracted from those 7 paired APA and AAG tissues. Gene expression and genome-wide DNA methylation profiles were obtained using SurePrint G3 Human GE 8x60K Microarray (Agilent) and Infinium HumanMethylation450 Beadchip (Illumina), respectively. Transcriptome anlaysis identified 244 significantly (2 fold<) upregulated genes in APA compared to AAG. The upregulated genes include the previously studied genes such as PCP4, ALDH1A2, and CYP11B2, and other genes that have not been previously studied, such as HOXA9, HOXA11, and HOXB9. Gene ontology (GO) analysis for these upregulated genes identified the calcium signaling pathway to be most significantly enriched with the upregulated genes (8 genes). Methylome analysis revealed that APA was globally hypomethylated compared to AAG regardless of gene feature groups, namely, TSS1500, TSS200, 5’UTR, 1stExon, gene body, and 3’UTR. GO analysis for the genes showing hypomethylation at TSS1500/TSS200 regions in APA identified the term “cytokine-cytokine receptor interaction” to be most significantly enriched with hypomethylated genes (37 genes). Integrated analysis of gene expression and genome-wide DNA methylation profiles identified 18 genes that are upregulated and whose TSS1500/TSS200 regions are hypomethylated in APA compared to AAG. These genes include CYP11B2 and MC2R (ACTH receptor). In conclusion, this is the first genome-wide study for PA that integrated transcriptome and methylome data. Global DNA hypomethylation in APA and concordant transcriptional up-regulation of some key genes, such as CYP11B2 and MC2R, may play crucial roles in the pathophysiological significance in PA. Adrenal specimens were obtained from 7 Japanese patients with APA, who underwent adrenalectomy at Tokyo Medical and Dental University. RNA and DNA samples were extracted from those 7 paired APA and AAG tissues. Gene expression and genome-wide DNA methylation profiles were obtained using SurePrint G3 Human GE 8x60K Microarray (Agilent) and Infinium HumanMethylation450 Beadchip (Illumina), respectively.
Project description:Primary and secondary hypertension are major risk factors for cardiovascular disease. Elevated secretion of aldosterone resulting from primary aldosteronism (PA) is a key driver of secondary hypertension. Here, we identify an unexpected role for the ubiquitin ligase Siah1 in adrenal gland development and PA. Siah1a-/- mice exhibit altered adrenal gland morphology, as reflected by dysregulated zonation of the glomerulosa, increased aldosterone levels and aldosterone target gene expression, and reduced plasma potassium levels. Genes involved in catecholamine biosynthesis and cAMP signaling are upregulated in the adrenal glands of Siah1a-/- mice, while genes related to retinoic acid signaling and cholesterol biosynthesis are downregulated. Loss of Siah1 leads to increased expression of PIAS1, an E3 SUMO-protein ligase implicated in the suppression of LXR. Notably, SIAH1 sequence variants which impaired SIAH1 ubiquitin ligase activity, resulting in elevated PIAS1 expression, were identified in patients with PA. The involvement of Siah1–PIAS1 in adrenal gland organization and function points to a possible new therapeutic target for hyperaldosteronism.
Project description:Primary aldosteronism is frequently caused by an adrenocortical aldosterone-producing adenoma (APA) carrying a somatic mutation that drives aldosterone overproduction. APAs with a mutation in KCNJ5 (APA-KCNJ5MUT) are characterized by heterogeneous CYP11B2 (aldosterone synthase) expression, a particular cellular composition and larger tumor diameter than those with wild-type KCNJ5 (APA-KCNJ5WT). Here, we used spatial transcriptomics profiling of adrenal tissue cryosections to define the role of transcriptomic reprogramming in APA pathophysiology. Our findings advance the understanding of the transcriptional context of inter- and intra-tumoral APA heterogeneity and provide novel insight into the genotype-dependent tumor expansion capabilities of APAs.
Project description:The source of aldosterone in 30 to 40 % of patients with primary hyperaldosteronism (PA) is unilateral aldosterone-producing adenoma (APA). The mechanisms causing elevated aldosterone production in APA are unknown. Herein, we examined expression of G-protein coupled receptors (GPCR) in APA and demonstrate that compared to normal adrenals there is a general elevation of certain GPCR in many APA and/or ectopic expression of GPCR in others. RNA samples from normal adrenals (n = 5), APAs (n = 10), and cortisol-producing adenomas (CPAs) (n=13) were used on 15 genomic expression arrays, each of which included 223 GPCR transcripts presented in at least one out of 15 of the independent microarrays. The array results were confirmed using real-time RT-PCR (qPCR). Four GPCR transcripts exhibited a statistically significant increase that was greater than 3-fold compared to normal adrenals, suggesting a general increase in expression compared to normal adrenal glands. Four GPCR transcripts exhibited a greater than 15-fold increase of expression in one or more of the APA samples compared to normal adrenals. qPCR analysis confirmed array data and found the receptors with the highest fold increase in APA expression to be luteinizing hormone receptor (LH-R), serotonin receptor 4 (HTR4), gonadotropin-releasing hormone receptor (GnRHR), glutamate receptor metabotropic 3 (GRM3), endothelin receptor type B-like protein (GPR37), and ACTH receptor (MC2R). There are also sporadic increased expressions of these genes in the CPAs. Together, these findings suggest a potential role of altered GPCR expression in many cases of PA and provide candidate GPCR for further study. Keywords: disease state analysis
Project description:Aldosterone-producing adenomas (APA) are heterogeneous. The objectives of this study were to compare the transcriptional profiles in APA and normal adjacent adrenal gland (AAG). This was done through the Illumina beadchip analysis of RNA from eight paired APA-AAG. Other tissues (phaeochromocytoma, cushing, and hyperplastic adrenals) were included as controls.
Project description:Introduction: Primary aldosteronism (PA) is a major cause of secondary hypertension. The two principal forms of PA are bilateral adrenal hyperplasia (BAH) and aldosterone-producing adenoma (APA) whose differentiation is clinically pivotal, due to their different treatments. Adrenal venous sampling (AVS) is considered to be the gold standard for the differentiation of the two clinical entities, but it is invasive, requires great expertise and is unavailable in many centers. There would be a major clinical need for a reliable and easily accessible diagnostic biomarker. Circulating microRNA were shown to be useful as minimally invasive diagnostic markers in many diseases, but their potential applicability in PA has not yet been investigated. Aims: To determine and compare the circulating microRNA expression profiles of AVS-confirmed APA and BAH plasma samples, and to evaluate their applicability as minimally invasive markers. Methods: 81 AVS-confirmed plasma samples were included. Next-generation sequencing (NGS) was performed on 30 EDTA-anticoagulated plasma samples. Significantly differently expressed miRNAs were validated by real-time RT-qPCR on all samples. Results: We have found relative overexpression of miR-30e-5p, miR-30d-5p, miR-223-3p and miR-7-5p in BAH compared to APA by NGS. Validation of 81 samples confirmed significant overexpression (p=0.03) of miR-7-5p. Regarding the microRNA expressional variations, APA is more heterogenous at the miRNA level compared to BAH. Conclusion: miR-7-5p was significantly overexpressed in BAH samples compared to APA samples, but its sensitivity and specificity values are not good enough for introduction to the clinical practice yet.
Project description:Primary aldosteronism (PA) is a common form of endocrine hypertension suspected in the presence of arterial hypertension (HT), hypokalemia and low plasma renin levels. While for a long time the genetic causes of PA have remained mysterious, recent findings have revealed an important role for an altered function of potassium channels in the pathogenesis of this disease. The basis for the unique sensitivity of adrenal zona glomerulosa (ZG) cells for plasma potassium concentration is a very high background potassium conductance, which is dependent on expression at high levels of two 2-pore domain (K2P) potassium channels, Task1 (KCNK3) and Task3 (KCNK9. Recent studies have shown that mice lacking Kcnk3 (Task1) or both Kcnk3 and Kcnk9 have PA. In Kcnk3 null mice, hyperaldosteronism is present in young animals of either sex, but is corrected in males after puberty. Strikingly, in these animals hyperaldosteronism associates with abnormal adrenal cortex functional zonation, since Cyp11b2, the rate-limiting enzyme for aldosterone production, is expressed in the inner region of the adrenal cortex and not in the glomerulosa. Additionally, this phenotype is under the control of sex hormones, as shown by the fact that castration of male Kcnk3 -/- animals prevents normal Cyp11b2 distribution, while testosterone injection in female Kcnk3 null mice restores expression of Cyp11b2 in ZG cells. We took advantage of the unique characteristics of the Kcnk3 null mouse model to search for genes that can modify their phenotype of PA and adrenocortical functional zonation. Using gene expression profiling in the adrenal glands of Kcnk3 null mice and exploiting the possibility of modulation of their phenotype by sexual hormones, we identified a cluster of genes closely associated with hyperaldosteronism in a sex- and hormone-dependent dynamic fashion. Among these genes, we focused our attention on Dkk3 (dickkopf3), encoding a peculiar member of the dickkopf family of Wnt signalling modulators because of its close association with aldosterone-producing cells in humans (11). Inactivation of Dkk3 in the Kcnk3 null background causes extension of the hyperaldosteronemic phenotype and increased expression of Cyp11b2 in the adrenal gland to the male sex, without affecting functional zonation. These data indicate that Dkk3 is a component of the genetic circuitry regulating expression of Cyp11b2 and suggest that it may be implicated in the pathogenesis of low-renin hyperaldosteronism in humans. One color -experiment with 2 strains of mice: C57BL/6 WT or Kcnk3 null (KO): male and female in basal conditions or following hormonal treatment (castration for males and testosterone injection for females), corresponding to 8 groups of animals. Total of 24 samples (n=3).
Project description:Primary aldosteronism (PA) is the most common endocrine hypertension comprising 10% of hypertensive patients. A recent series of transcriptome analyses using DNA microarray has shown that neumerous genes are differentially expressed between aldosterone-producing adenoma (APA) and its adjacent adrenal gland (AAG) tissue from the same patient. However, the molecular mechanism(s) of pathogenesis of APA has not yet been fully clarified. Although growing body of evidence has shown that epigenetic abnormalities including DNA methylation play a key role in tumorigenesis, there are few studies with regard to DNA methylation in APA. In the present study, to elucidate the pathogenic relationship between gene expression and DNA methylation in PA, we conducted an integrated analysis of transcriptome and methylome data for paired APA-AAG samples from the same patient. Adrenal specimens were obtained from 7 Japanese patients with APA, who underwent adrenalectomy at Tokyo Medical and Dental University. RNA and DNA samples were extracted from those 7 paired APA and AAG tissues. Gene expression and genome-wide DNA methylation profiles were obtained using SurePrint G3 Human GE 8x60K Microarray (Agilent) and Infinium HumanMethylation450 Beadchip (Illumina), respectively. Transcriptome anlaysis identified 244 significantly (2 fold<) upregulated genes in APA compared to AAG. The upregulated genes include the previously studied genes such as PCP4, ALDH1A2, and CYP11B2, and other genes that have not been previously studied, such as HOXA9, HOXA11, and HOXB9. Gene ontology (GO) analysis for these upregulated genes identified the calcium signaling pathway to be most significantly enriched with the upregulated genes (8 genes). Methylome analysis revealed that APA was globally hypomethylated compared to AAG regardless of gene feature groups, namely, TSS1500, TSS200, 5’UTR, 1stExon, gene body, and 3’UTR. GO analysis for the genes showing hypomethylation at TSS1500/TSS200 regions in APA identified the term “cytokine-cytokine receptor interaction” to be most significantly enriched with hypomethylated genes (37 genes). Integrated analysis of gene expression and genome-wide DNA methylation profiles identified 18 genes that are upregulated and whose TSS1500/TSS200 regions are hypomethylated in APA compared to AAG. These genes include CYP11B2 and MC2R (ACTH receptor). In conclusion, this is the first genome-wide study for PA that integrated transcriptome and methylome data. Global DNA hypomethylation in APA and concordant transcriptional up-regulation of some key genes, such as CYP11B2 and MC2R, may play crucial roles in the pathophysiological significance in PA.