Publications by authors named "Eva Szarek"

24 Publications

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Pde8b haploinsufficiency in mice is associated with modest adrenal defects, impaired steroidogenesis, and male infertility, unaltered by concurrent PKA or Wnt activation.

Mol Cell Endocrinol 2021 02 15;522:111117. Epub 2020 Dec 15.

Section on Endocrinology and Genetics, Program on Developmental Endocrinology & Genetics (PDEGEN), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD, 20892, USA. Electronic address:

PDE8B, PRKAR1A and the Wnt/β-catenin signaling are involved in endocrine disorders. However, how PDEB8B interacts with both Wnt and protein kinase A (PKA) signaling in vivo remains unknown. We created a novel Pde8b knockout mouse line (Pde8b); Pde8b haploinsufficient (Pde8b) mice were then crossed with mice harboring: (1) constitutive beta-catenin activation (Pde8b;ΔCat) and (2) Prkar1a haploinsufficieny (Pde8b;Prkar1a). Adrenals and testes from mice (3-12-mo) were evaluated in addition to plasma corticosterone, aldosterone and Dkk3 concentrations, and the examination of expression of steroidogenesis-, Wnt- and cAMP/PKA-related genes. Pde8b male mice were infertile with down-regulation of the Wnt/β-catenin pathway which did not change significantly in the Pde8b;ΔCat mice. Prkar1a haploinsufficiency also did not change the phenotype significantly. In vitro studies showed that PDE8B knockdown upregulated the Wnt pathway and increased proliferation in CTNNB1-mutant cells, whereas it downregulated the Wnt pathway in PRKAR1A-mutant cells. These data support an overall weak, if any, role for PDE8B in adrenocortical tumorigenesis, even when co-altered with Wnt signaling or PKA upregulation; on the other hand, PDE8B appears to play a significant role in male fertility.
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http://dx.doi.org/10.1016/j.mce.2020.111117DOI Listing
February 2021

A phosphodiesterase 11 (Pde11a) knockout mouse expressed functional but reduced Pde11a: Phenotype and impact on adrenocortical function.

Mol Cell Endocrinol 2021 01 27;520:111071. Epub 2020 Oct 27.

Section on Endocrinology & Genetics (SEGEN), Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, 20892, USA. Electronic address:

Phosphodiesterases catalyze the hydrolysis of cyclic nucleotides and maintain physiologic levels of intracellular concentrations of cyclic adenosine and guanosine mono-phosphate (cAMP and cGMP, respectively). Increased cAMP signaling has been associated with adrenocortical tumors and Cushing syndrome. Genetic defects in phosphodiesterase 11A (PDE11A) may lead to increased cAMP signaling and have been found to predispose to the development of adrenocortical, prostate, and testicular tumors. A previously reported Pde11a knockout (Pde11a) mouse line was studied and found to express PDE11A mRNA and protein still, albeit at reduced levels; functional studies in various tissues showed increased cAMP levels and reduced PDE11A activity. Since patients with PDE11A defects and Cushing syndrome have PDE11A haploinsufficiency, it was particularly pertinent to study this hypomorphic mouse line. Indeed, Pde11a mice failed to suppress corticosterone secretion in response to low dose dexamethasone, and in addition exhibited adrenal subcapsular hyperplasia with predominant fetal-like features in the inner adrenal cortex, mimicking other mouse models of increased cAMP signaling in the adrenal cortex. We conclude that a previously reported Pde11a mouse showed continuing expression and function of PDE11A in most tissues. Nevertheless, Pde11a partial inactivation in mice led to an adrenocortical phenotype that was consistent with what we see in patients with PDE11A haploinsufficiency.
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http://dx.doi.org/10.1016/j.mce.2020.111071DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7771190PMC
January 2021

Lipofuscin Accumulation in Cortisol-Producing Adenomas With and Without PRKACA Mutations.

Horm Metab Res 2017 Oct 23;49(10):786-792. Epub 2017 Aug 23.

Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland 20892, USA.

The adrenal cortex accumulates lipofuscin granules with age. Lipofuscin accumulation is also seen in adrenocortical tumors associated with Cushing syndrome (CS), particularly those with mutations, such as in primary pigmented nodular adrenocortical disease (PPNAD). We investigated the presence of lipofuscin in cortisol-producing adenomas (CPAs) responsible for CS with and without the (pLeu206Arg) somatic mutation. Ten paraffin-embedded sections of CPAs from cases with overt CS with (n=4) and without (n=6) a mutation were microscopically examined through three detection methods, the hematoxylin-Eosin (H & E) staining, the Fontana Masson (FM) staining using light microscopy, and lipofuscin autofluorescence, using confocal laser scanning microscopy (CLSM). Sections were examined quantitatively according to the intensity of the pigmentation, as well as qualitatively based on the total number of granular pigments at all visual fields per tissue slide. Tissues from CPAs were compared to peritumoral adjacent tissues (n=5), to Conn adenomas (n=4), and PPNAD (n=3). CPAs had significantly higher number of lipofuscin-pigment granules compared to peritumoral adrenal tissue and Conn adenomas (46.9±9.5 vs. 3.8±4.8, p=0.0001). The presence of the mutation did not increase the chances of pigmentation in the form of lipofuscin granules within CPAs associated with CS. Thus, all CPAs leading to CS accumulate lipofuscin, which presents like pigmentation sometimes seen macroscopically but always detected microscopically. PPNAD caused by mutations is the best known adrenal lesion leading to CS associated with intense lipofuscin pigmentation and this was confirmed here; CPAs harboring mutations did not have statistically significantly more pigmentation than CPAs without mutation, but a larger study might have shown a difference.
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http://dx.doi.org/10.1055/s-0043-116385DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6299839PMC
October 2017

Prkar1a gene knockout in the pancreas leads to neuroendocrine tumorigenesis.

Endocr Relat Cancer 2017 01 1;24(1):31-40. Epub 2016 Nov 1.

Section on Endocrinology and GeneticsProgram on Developmental Endocrinology & Genetics (PDEGEN) & Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland, USA

Carney complex (CNC) is a rare disease associated with multiple neoplasias, including a predisposition to pancreatic tumors; it is caused most frequently by the inactivation of the PRKAR1A gene, a regulator of the cyclic AMP (cAMP)-dependent kinase (PKA). The method used was to create null alleles of prkar1a in mouse cells expressing pdx1 (Δ-Prkar1a). We found that these mice developed endocrine or mixed endocrine/acinar cell carcinomas with 100% penetrance by the age of 4-5 months. Malignant behavior of the tumors was seen as evidenced by stromal invasion and metastasis to locoregional lymph nodes. Histologically, most tumors exhibited an organoid pattern as seen in the islet-cell tumors. Biochemically, the lesions exhibited high PKA activity, as one would expect from deleting prkar1a The primary neuroendocrine nature of these tumor cells was confirmed by immunohistochemical staining and electron microscopy, the latter revealing the characteristic granules. Although the Δ-Prkar1a mice developed hypoglycemia after overnight fasting, insulin and glucagon levels in the plasma were normal. Negative immunohistochemical staining for the most commonly produced peptides (insulin, c-peptide, glucagon, gastrin and somatostatin) suggested that these tumors were non-functioning. We hypothesize that the recently identified multipotent pdx1+/insulin- cell in adult pancreas, gives rise to endocrine or mixed endocrine/acinar pancreatic malignancies with complete prkar1a deficiency. In conclusion, this mouse model supports the role of prkar1a as a tumor suppressor gene in the pancreas and points to the PKA pathway as a possible therapeutic target for these lesions.
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http://dx.doi.org/10.1530/ERC-16-0443DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5123945PMC
January 2017

PKA regulatory subunit 1A inactivating mutation induces serotonin signaling in primary pigmented nodular adrenal disease.

JCI Insight 2016 Sep 22;1(15):e87958. Epub 2016 Sep 22.

Normandie University, UNIROUEN, INSERM, U982, Laboratoire Differenciation et Communication Neuronale et Neuroendocrine, 76000 Rouen, France.

Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of ACTH-independent hypercortisolism. The disease is primarily caused by germline mutations of the protein kinase A (PKA) regulatory subunit 1A () gene, which induces constitutive activation of PKA in adrenocortical cells. Hypercortisolism is thought to result from PKA hyperactivity, but PPNAD tissues exhibit features of neuroendocrine differentiation, which may lead to stimulation of steroidogenesis by abnormally expressed neurotransmitters. We hypothesized that serotonin (5-HT) may participate in the pathophysiology of PPNAD-associated hypercortisolism. We show that PPNAD tissues overexpress the 5-HT synthesizing enzyme tryptophan hydroxylase type 2 (Tph2) and the serotonin receptors types 4, 6, and 7, leading to formation of an illicit stimulatory serotonergic loop whose pharmacological inhibition in vitro decreases cortisol production. In the human PPNAD cell line CAR47, the PKA inhibitor H-89 decreases 5-HT and 5-HT receptor expression. Moreover, in the human adrenocortical cell line H295R, inhibition of expression increases the expression of Tph2 and 5-HT receptors, an effect that is blocked by H-89. These findings show that the serotonergic process observed in PPNAD tissues results from PKA activation by mutations. They also suggest that Tph inhibitors may represent efficient treatments of hypercortisolism in patients with PPNAD.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5033753PMC
http://dx.doi.org/10.1172/jci.insight.87958DOI Listing
September 2016

Celecoxib reduces glucocorticoids in vitro and in a mouse model with adrenocortical hyperplasia.

Endocr Relat Cancer 2016 Jan 5;23(1):15-25. Epub 2015 Oct 5.

Section on Endocrinology and Genetics (SEGEN)Program on Developmental Endocrinology and Genetics (PDEGEN), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, 10 Center Drive, Building 10-Clinical Research Center, Room 1-3330, Bethesda, Maryland 20892, USAOffice of Research Services (ORS)Division of Veterinary Resources (DVR), Office of the Director (OD), National Institutes of Health, Bethesda, Maryland 20892, USACNRS UMR6247Génétique Reproduction et Développement, Clermont Université, Aubière, France.

Primary pigmented nodular adrenocortical disease (PPNAD), whether in the context of Carney complex (CNC) or isolated, leads to ACTH-independent Cushing's syndrome (CS). CNC and PPNAD are caused typically by inactivating mutations of PRKAR1A, a gene coding for the type 1a regulatory subunit (R1α) of cAMP-dependent protein kinase (PKA). Mice lacking Prkar1a, specifically in the adrenal cortex (AdKO) developed CS caused by bilateral adrenal hyperplasia (BAH), which is formed from the abnormal proliferation of fetal-like adrenocortical cells. Celecoxib is a cyclooxygenase 2 (COX2) inhibitor. In bone, Prkar1a inhibition is associated with COX2 activation and prostaglandin E2 (PGE2) production that, in turn, activates proliferation of bone stromal cells. We hypothesized that COX2 inhibition may have an effect in PPNAD. In vitro treatment of human cell lines, including one from a patient with PPNAD, with celecoxib resulted in decreased cell viability. We then treated AdKO and control mice with 1500 mg/kg celecoxib or vehicle. Celecoxib treatment led to decreased PGE2 and corticosterone levels, reduced proliferation and increased apoptosis of adrenocortical cells, and decreased steroidogenic gene expression. We conclude that, in vitro and in vivo, celecoxib led to decreased steroidogenesis. In a mouse model of PPNAD, celecoxib caused histological changes that, at least in part, reversed BAH and this was associated with a reduction of corticosterone levels.
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http://dx.doi.org/10.1530/ERC-15-0472DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4659722PMC
January 2016

Haploinsufficiency for either one of the type-II regulatory subunits of protein kinase A improves the bone phenotype of Prkar1a+/- mice.

Hum Mol Genet 2015 Nov 5;24(21):6080-92. Epub 2015 Aug 5.

Section on Endocrinology and Genetics (SEGEN), Program on Developmental Endocrinology & Genetics (PDEGEN), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD),

Carney Complex (CNC), a human genetic syndrome predisposing to multiple neoplasias, is associated with bone lesions such as osteochondromyxomas (OMX). The most frequent cause for CNC is PRKAR1A deficiency; PRKAR1A codes for type-I regulatory subunit of protein kinase A (PKA). Prkar1a(+/-) mice developed OMX, fibrous dysplasia-like lesions (FDL) and other tumors. Tumor tissues in these animals had increased PKA activity due to an unregulated PKA catalytic subunit and increased PKA type II (PKA-II) activity mediated by the PRKAR2A and PRKAR2B subunits. To better understand the effect of altered PKA activity on bone, we studied Prkar2a and Prkar2b knock out (KO) and heterozygous mice; none of these mice developed bone lesions. When Prkar2a(+/-) and Prkar2b(+/-) mice were used to generate Prkar1a(+/-)Prkar2a(+/-) and Prkar1a(+/-)Prkar2b(+/-) animals, bone lesions formed that looked like those of the Prkar1a(+/-) mice. However, better overall bone organization and mineralization and fewer FDL lesions were found in both double heterozygote groups, indicating a partial restoration of the immature bone structure observed in Prkar1a(+/-) mice. Further investigation indicated increased osteogenesis and higher new bone formation rates in both Prkar1a(+/-)Prkar2a(+/-) and Prkar1a(+/-)Prkar2b(+/-) mice with some minor differences between them. The observations were confirmed with a variety of markers and studies. PKA activity measurements showed the expected PKA-II decrease in both double heterozygote groups. Thus, haploinsufficiency for either of PKA-II regulatory subunits improved bone phenotype of mice haploinsufficient for Prkar1a, in support of the hypothesis that the PRKAR2A and PRKAR2B regulatory subunits were in part responsible for the bone phenotype of Prkar1a(+/-) mice.
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http://dx.doi.org/10.1093/hmg/ddv320DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4599668PMC
November 2015

Carney triad can be (rarely) associated with germline succinate dehydrogenase defects.

Eur J Hum Genet 2016 Apr 15;24(4):569-73. Epub 2015 Jul 15.

Section on Endocrinology and Genetics (SEGEN), Program on Developmental Endocrinology and Genetics (PDEGEN), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA.

Carney triad, the association of paragangliomas/pheochromocytomas, gastrointestinal stromal tumors and pulmonary chondromas, is a sporadic condition that is significantly more frequent in females; its genetic etiology remains unknown. Carney triad is distinct from the dyad of paragangliomas/pheochromocytomas and gastrointestinal stromal tumors, known as Carney-Stratakis syndrome, which is inherited in an autosomal- dominant manner and is almost always caused by succinate dehydrogenase subunit mutations. In the present study, we investigated the largest cohort of Carney triad patients that is available internationally: 63 unrelated patients. Six patients (9.5%) were found to have germline variants in the SDHA, SDHB or SDHC genes. All six patients, except one, had multifocal gastrointestinal stromal tumors, chondromas and/or paragangliomas. A patient with Carney triad and SDHC variant had a ganglioneuroma. One of the patients with Carney triad and SDHB mutation had a nephew with the same sequence defect, who developed a neuroblastoma. Other relatives, carriers of the identified SDHA, SDHB or SDHC mutations, have not developed any of the components of Carney triad or Carney-Stratakis syndrome. None of the other 57 Carney triad patients had any genomic defects of SDHA, SDHB or SDHC genes. We conclude that, in rare occasions, Carney triad can be allelic to Carney-Stratakis syndrome. Although for the vast majority of patients with Carney triad the causative defect(s) remain(s) unknown, testing for SDHA, SDHB or SDHC variations should be offered, as carriers may develop isolated paragangliomas/pheochromocytomas and occasionally other tumors.
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http://dx.doi.org/10.1038/ejhg.2015.142DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4929866PMC
April 2016

PRKACA: the catalytic subunit of protein kinase A and adrenocortical tumors.

Front Cell Dev Biol 2015 20;3:26. Epub 2015 May 20.

Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics and Pediatric Endocrinology Inter-Institute Training Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA.

Cyclic-AMP (cAMP)-dependent protein kinase (PKA) is the main effector of cAMP signaling in all tissues. Inactivating mutations of the PRKAR1A gene, coding for the type 1A regulatory subunit of PKA, are responsible for Carney complex and primary pigmented nodular adrenocortical disease (PPNAD). PRKAR1A inactivation and PKA dysregulation have been implicated in various types of adrenocortical pathologies associated with ACTH-independent Cushing syndrome (AICS) from PPNAD to adrenocortical adenomas and cancer, and other forms of bilateral adrenocortical hyperplasias (BAH). More recently, mutations of PRKACA, the gene coding for the catalytic subunit C alpha (Cα), were also identified in the pathogenesis of adrenocortical tumors. PRKACA copy number gain was found in the germline of several patients with cortisol-producing BAH, whereas the somatic Leu206Arg (c.617A>C) recurrent PRKACA mutation was found in as many as half of all adrenocortical adenomas associated with AICS. In vitro analysis demonstrated that this mutation led to constitutive Cα activity, unregulated by its main partners, the PKA regulatory subunits. In this review, we summarize the current understanding of the involvement of PRKACA in adrenocortical tumorigenesis, and our understanding of PKA's role in adrenocortical lesions. We also discuss potential therapeutic advances that can be made through targeting of PRKACA and the PKA pathway.
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http://dx.doi.org/10.3389/fcell.2015.00026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4438593PMC
June 2015

Phosphodiesterase sequence variants may predispose to prostate cancer.

Endocr Relat Cancer 2015 Aug 15;22(4):519-30. Epub 2015 May 15.

Section on Endocrinology and GeneticsProgram on Developmental Endocrinology and Genetics (PDEGEN) and Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USASchool of Health and BiosciencesPontifícia Universidade Católica do Paraná (PUCPR), Curitiba, PR 80215-901, BrazilDepartment of Pharmacology and PhysiologyGeorge Washington University, Washington, DC 20037, USALaboratory of Genomics and Molecular BiologyCIPEDepartment of PathologyA.C. Camargo Cancer Center, 01509-010 São Paulo, SP, BrazilDepartment of StatisticsGeorge Washington University, Washington, DC 20037, USA Section on Endocrinology and GeneticsProgram on Developmental Endocrinology and Genetics (PDEGEN) and Pediatric Endocrinology Inter-institute Training Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD 20892, USASchool of Health and BiosciencesPontifícia Universidade Católica do Paraná (PUCPR), Curitiba, PR 80215-901, BrazilDepartment of Pharmacology and PhysiologyGeorge Washington University, Washington, DC 20037, USALaboratory of Genomics and Molecular BiologyCIPEDepartment of PathologyA.C. Camargo Cancer Center, 01509-010 São Paulo, SP, BrazilDepartment of StatisticsGeorge Washington University, Washington, DC 20037, USA

We hypothesized that mutations that inactivate phosphodiesterase (PDE) activity and lead to increased cAMP and cyclic guanosine monophosphate levels may be associated with prostate cancer (PCa). We sequenced the entire PDE coding sequences in the DNA of 16 biopsy samples from PCa patients. Novel mutations were confirmed in the somatic or germline state by Sanger sequencing. Data were then compared to the 1000 Genome Project. PDE, CREB and pCREB protein expression was also studied in all samples, in both normal and abnormal tissue, by immunofluorescence. We identified three previously described PDE sequence variants that were significantly more frequent in PCa. Four novel sequence variations, one each in the PDE4B,PDE6C, PDE7B and PDE10A genes, respectively, were also found in the PCa samples. Interestingly, PDE10A and PDE4B novel variants that were present in 19 and 6% of the patients were found in the tumor tissue only. In patients carrying PDE defects, there was pCREB accumulation (P<0.001), and an increase of the pCREB:CREB ratio (patients 0.97±0.03; controls 0.52±0.03; P-value <0.001) by immunohistochemical analysis. We conclude that PDE sequence variants may play a role in the predisposition and/or progression to PCa at the germline and/or somatic state respectively.
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http://dx.doi.org/10.1530/ERC-15-0134DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4499475PMC
August 2015

Phosphodiesterase 8B and cyclic AMP signaling in the adrenal cortex.

Endocrine 2015 Sep 14;50(1):27-31. Epub 2015 May 14.

Section on Endocrinology and Genetics, Program on Developmental Endocrinology & Genetics (PDEGEN) Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, 10 Center Drive, Building 10, NIH-Clinical Research Center, Room 1-3216, Bethesda, MD, 20892, USA.

Bilateral adrenocortical hyperplasia (BAH) in humans and mice has been recently linked to phosphodiesterase (PDE) 8B (PDE8B) and 11 (PDE11A) defects. These findings have followed the discovery that defects of primary genes of the cyclic monophosphatase (cAMP) signaling pathway, such as guanine nucleotide binding alpha subunit and PRKAR1A, are involved in the pathogenesis of BAH in humans; complete absence of Prkar1a in the adrenal cortex of mice also led to pathology that mimicked the human disease. Here, we review the most recent findings in human and mouse studies on PDE8B, a cAMP-specific PDE that appears to be highly expressed in the adrenal cortex and whose deficiency may underlie predisposition to BAH and possibly other human diseases.
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http://dx.doi.org/10.1007/s12020-015-0621-yDOI Listing
September 2015

Germline PRKACA amplification causes variable phenotypes that may depend on the extent of the genomic defect: molecular mechanisms and clinical presentations.

Eur J Endocrinol 2015 06;172(6):803-11

Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Building 10-CRC, Room 9D42, 10 Center Drive, MSC, 1103, Bethesda, Maryland 20892, USA

Objective: We have recently reported five patients with bilateral adrenocortical hyperplasia (BAH) and Cushing's syndrome (CS) caused by constitutive activation of the catalytic subunit of protein kinase A (PRKACA). By doing new in-depth analysis of their cytogenetic abnormality, we attempted a better genotype-phenotype correlation of their PRKACA amplification.

Design: This study is a case series.

Methods: Molecular cytogenetic, genomic, clinical, and histopathological analyses were performed in five patients with CS.

Results: Reinvestigation of the defects of previously described patients by state-of-the-art molecular cytogenetics showed complex genomic rearrangements in the chromosome 19p13.2p13.12 locus, resulting in copy number gains encompassing the entire PRKACA gene; three patients (one sporadic case and two related cases) were observed with gains consistent with duplications, while two sporadic patients were observed with gains consistent with triplications. Although all five patients presented with ACTH-independent CS, the three sporadic patients had micronodular BAH and underwent bilateral adrenalectomy in early childhood, whereas the two related patients, a mother and a son, presented with macronodular BAH as adults. In at least one patient, PRKACA triplication was associated with a more severe phenotype.

Conclusions: Constitutional chromosomal PRKACA gene amplification is a recently identified genetic defect associated with CS, a trait that may be inherited in an autosomal dominant manner or occur de novo. Genomic rearrangements can be complex and can result in different copy number states of dosage-sensitive genes, e.g., duplication and triplication. PRKACA amplification can lead to variable phenotypes clinically and pathologically, both micro- and macro-nodular BAH, the latter of which we speculate may depend on the extent of amplification.
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http://dx.doi.org/10.1530/EJE-14-1154DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4428149PMC
June 2015

Carney triad, SDH-deficient tumors, and Sdhb+/- mice share abnormal mitochondria.

Endocr Relat Cancer 2015 Jun 25;22(3):345-52. Epub 2015 Mar 25.

Section on Endocrinology and Genetics (SEGEN)Program on Developmental Endocrinology and Genetics (PDEGEN), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Building 10, CRC, Room 1-3330, 10 Center Drive, MSC1103, Bethesda, Maryland 20892, USADepartment of Biophysics and Nuclear MedicineUniversity Hospitals of Strasbourg, Strasbourg, FranceFaculty of MedicineIcube UMR 7357 University of Strasbourg/CNRS and FMTS, Strasbourg, FranceLaboratory of PathologyNational Cancer Institute (NCI), NIH, Bethesda, Maryland 20892, USASection on Medical Neuroendocrinology (SMN)Program on Reproductive and Adult Endocrinology (PRAE), NICHD, NIH, Bethesda, Maryland 20892, USASection of Immunopathology and Laboratory of ImmunologyNational Eye Institute, U.S. National Institutes of Health, Bethesda, Maryland 20892, USADepartment of Nuclear MedicineLa Timone University Hospital, CERIMED, 264, Rue Saint-Pierre, 13385 Marseille Cedex 5, FranceInstitut Paoli-CalmettesInserm UMR1068 Marseille Cancerology Research Center, Marseille, FranceEmeritus Staff CenterMayo Clinic Rochester, 200 First Street Southwest, Rochester, Minnesota 55905, USA

Carney triad (CTr) describes the association of paragangliomas (PGL), pulmonary chondromas, and gastrointestinal (GI) stromal tumors (GISTs) with a variety of other lesions, including pheochromocytomas and adrenocortical tumors. The gene(s) that cause CTr remain(s) unknown. PGL and GISTs may be caused by loss-of-function mutations in succinate dehydrogenase (SDH) (a condition known as Carney-Stratakis syndrome (CSS)). Mitochondrial structure and function are abnormal in tissues that carry SDH defects, but they have not been studied in CTr. For the present study, we examined mitochondrial structure in human tumors and GI tissue (GIT) of mice with SDH deficiency. Tissues from 16 CTr tumors (n=12), those with isolated GIST (n=1), and those with CSS caused by SDHC (n=1) and SDHD (n=2) mutations were studied by electron microscopy (EM). Samples of GIT from mice with a heterozygous deletion in Sdhb (Sdhb(+) (/-), n=4) were also studied by EM. CTr patients presented with mostly epithelioid GISTs that were characterized by plump cells containing a centrally located, round nucleus and prominent nucleoli; these changes were almost identical to those seen in the GISTs of patients with SDH. In tumor cells from patients, regardless of diagnosis or tumor type, cytoplasm contained an increased number of mitochondria with a 'hypoxic' phenotype: mitochondria were devoid of cristae, exhibited structural abnormalities, and were of variable size. Occasionally, mitochondria were small and round; rarely, they were thin and elongated with tubular cristae. Many mitochondria exhibited amorphous fluffy material with membranous whorls or cystic structures. A similar mitochondrial hypoxic phenotype was seen in Sdhb(+) (/-) mice. We concluded that tissues from SDH-deficient tumors, those from mouse GIT, and those from CTr tumors shared identical abnormalities in mitochondrial structure and other features. Thus, the still-elusive CTr defect(s) is(are) likely to affect mitochondrial function, just like germline SDH-deficiency does.
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http://dx.doi.org/10.1530/ERC-15-0069DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4433412PMC
June 2015

Pituitary adenoma with paraganglioma/pheochromocytoma (3PAs) and succinate dehydrogenase defects in humans and mice.

J Clin Endocrinol Metab 2015 May 19;100(5):E710-9. Epub 2015 Feb 19.

Section on Endocrinology and Genetics (P.X., E.S., S.A.M., P.M., M.R., N.R., M.d.L.L.S., C.L., E.B., M.L., C.A.S.), Program on Developmental Endocrinology and Genetics, Section on Medical Neuroendocrinology (P.B., A.G.), Program in Reproductive and Adult Endocrinology, Section on Molecular Dysmorphology (C.A.W., A.C.), Program in Developmental Endocrinology and Genetics, Microscopy and Imaging Core (L.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Laboratory of Pathology (A.G., M.Q., K.P.), National Cancer Institute, and Biostatistics and Clinical Epidemiology Service (D.K.), Clinical Center, National Institutes of Health, Bethesda, Maryland 20892; Department of Endocrinology (C.M.), University of Connecticut Health Center, Farmington, Connecticut 06030; Genomic Medicine Institute (J.M., C.E.), Cleveland Clinic, Cleveland, Ohio 44195; Department of Biochemistry and Molecular Biology (L.J.M.), Mayo Clinic College of Medicine, Rochester, Minnesota 55905; and Department of Molecular Medicine (P.B.), Institute of Virology, Slovak Academy of Sciences, 833 06 Bratislava, Slovakia.

Context: Germline mutations in genes coding succinate dehydrogenase (SDH) subunits A, B, C, and D have been identified in familial paragangliomas (PGLs)/pheochromocytomas (PHEOs) and other tumors. We described a GH-secreting pituitary adenoma (PA) caused by SDHD mutation in a patient with familial PGLs. Additional patients with PAs and SDHx defects have since been reported.

Design: We studied 168 patients with unselected sporadic PA and with the association of PAs, PGLs, and/or pheochromocytomas, a condition we named the 3P association (3PAs) for SDHx germline mutations. We also studied the pituitary gland and hormonal profile of Sdhb(+/-) mice and their wild-type littermates at different ages.

Results: No SDHx mutations were detected among sporadic PA, whereas three of four familial cases were positive for a mutation (75%). Most of the SDHx-deficient PAs were either prolactinomas or somatotropinomas. Pituitaries of Sdhb(+/-) mice older than 12 months had an increased number mainly of prolactin-secreting cells and several ultrastructural abnormalities such as intranuclear inclusions, altered chromatin nuclear pattern, and abnormal mitochondria. Igf-1 levels of mutant mice tended to be higher across age groups, whereas Prl and Gh levels varied according to age and sex.

Conclusion: The present study confirms the existence of a new association that we termed 3PAs. It is due mostly to germline SDHx defects, although sporadic cases of 3PAs without SDHx defects also exist. Using Sdhb(+/-) mice, we provide evidence that pituitary hyperplasia in SDHx-deficient cells may be the initial abnormality in the cascade of events leading to PA formation.
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http://dx.doi.org/10.1210/jc.2014-4297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4422891PMC
May 2015

Is IGSF1 involved in human pituitary tumor formation?

Endocr Relat Cancer 2015 Feb 19;22(1):47-54. Epub 2014 Dec 19.

Section on Endocrinology and GeneticsProgram on Developmental Endocrinology and Genetics (PDEGEN) Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, NIH-Clinical Research Center, 10 Center Drive, Building 10, Room 1-3330, MSC1103, Bethesda, Maryland 20892, USAGroup for Advanced Molecular InvestigationGraduate Program in Health Science, Medical School, Pontificia Universidade Catolica do Paraná, Curitiba 80215, BrazilDepartment of Pharmacology and TherapeuticsMcGill University, Montréal, Québec, Canada H3G 1Y6Pediatric Endocrinology Inter-institute Training ProgramEunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, Maryland 20892, USAThe Liggins InstituteUniversity of Auckland, Auckland 1023, New ZealandTaranaki Base HospitalNew Plymouth 4310, New ZealandAuckland City Hospital & Greenlane Clinical CentreAuckland 1142, New ZealandDepartment of NeurosurgeryUniversity of Virginia Health Sciences Center, University of Virginia, Charlottesville, Virginia 22904, USASurgical Neurology BranchNational Institute for Neurological Diseases and Stroke (NINDS), National Institutes of Health, Bethesda, Maryland 20892, USA Departments ofEndocrinology and Metabolic DisordersPediatricsLeiden University Medical Center, Leiden 2333, The Netherlands Section on Endocrinology and GeneticsProgram on Developmental Endocrinology and Genetics (PDEGEN) Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, NIH-Clinical Research Center, 10 Center Drive, Building 10, Room 1-3330, MSC1103, Bethesda, Maryland 20892, USAGroup for Advanced Molecular InvestigationGraduate Program in Health Science, Medical School, Pontificia Universidade Catolica do Paraná, Curitiba 80215, BrazilDepartment of Pharmacology and TherapeuticsMcGill University, Montréal, Québec, Canada H3G 1Y6Pediatric

IGSF1 is a membrane glycoprotein highly expressed in the anterior pituitary. Pathogenic mutations in the IGSF1 gene (on Xq26.2) are associated with X-linked central hypothyroidism and testicular enlargement in males. In this study, we tested the hypothesis that IGSF1 is involved in the development of pituitary tumors, especially those that produce growth hormone (GH). IGSF1 was sequenced in 21 patients with gigantism or acromegaly and 92 healthy individuals. Expression studies with a candidate pathogenic IGSF1 variant were carried out in transfected cells and immunohistochemistry for IGSF1 was performed in the sections of GH-producing adenomas, familial somatomammotroph hyperplasia, and in normal pituitary. We identified the sequence variant p.N604T, which in silico analysis suggested could affect IGSF1 function, in two male patients and one female with somatomammotroph hyperplasia from the same family. Of 60 female controls, two carried the same variant and seven were heterozygous for other variants. Immunohistochemistry showed increased IGSF1 staining in the GH-producing tumor from the patient with the IGSF1 p.N604T variant compared with a GH-producing adenoma from a patient negative for any IGSF1 variants and with normal control pituitary tissue. The IGSF1 gene appears polymorphic in the general population. A potentially pathogenic variant identified in the germline of three patients with gigantism from the same family (segregating with the disease) was also detected in two healthy female controls. Variations in IGSF1 expression in pituitary tissue in patients with or without IGSF1 germline mutations point to the need for further studies of IGSF1 action in pituitary adenoma formation.
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http://dx.doi.org/10.1530/ERC-14-0465DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4272759PMC
February 2015

Gigantism and acromegaly due to Xq26 microduplications and GPR101 mutation.

N Engl J Med 2014 Dec 3;371(25):2363-74. Epub 2014 Dec 3.

The authors' affiliations are listed in the Appendix.

Background: Increased secretion of growth hormone leads to gigantism in children and acromegaly in adults; the genetic causes of gigantism and acromegaly are poorly understood.

Methods: We performed clinical and genetic studies of samples obtained from 43 patients with gigantism and then sequenced an implicated gene in samples from 248 patients with acromegaly.

Results: We observed microduplication on chromosome Xq26.3 in samples from 13 patients with gigantism; of these samples, 4 were obtained from members of two unrelated kindreds, and 9 were from patients with sporadic cases. All the patients had disease onset during early childhood. Of the patients with gigantism who did not carry an Xq26.3 microduplication, none presented before the age of 5 years. Genomic characterization of the Xq26.3 region suggests that the microduplications are generated during chromosome replication and that they contain four protein-coding genes. Only one of these genes, GPR101, which encodes a G-protein-coupled receptor, was overexpressed in patients' pituitary lesions. We identified a recurrent GPR101 mutation (p.E308D) in 11 of 248 patients with acromegaly, with the mutation found mostly in tumors. When the mutation was transfected into rat GH3 cells, it led to increased release of growth hormone and proliferation of growth hormone-producing cells.

Conclusions: We describe a pediatric disorder (which we have termed X-linked acrogigantism [X-LAG]) that is caused by an Xq26.3 genomic duplication and is characterized by early-onset gigantism resulting from an excess of growth hormone. Duplication of GPR101 probably causes X-LAG. We also found a recurrent mutation in GPR101 in some adults with acromegaly. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others.).
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http://dx.doi.org/10.1056/NEJMoa1408028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4291174PMC
December 2014

Differentially regulated protein kinase A (PKA) activity in adipose tissue and liver is associated with resistance to diet-induced obesity and glucose intolerance in mice that lack PKA regulatory subunit type IIα.

Endocrinology 2014 Sep 10;155(9):3397-408. Epub 2014 Jun 10.

Section on Endocrinology and Genetics (E.L., M.N., E.S., S.A.M., C.A.S.), Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Biostatistics and Clinical Epidemiology Service (N.S.), CC, National Institutes of Health, Mouse Metabolism Core Laboratory (T.C., O.G.), National Institute of Diabetes and Digestive and Kidney Diseases, and Eunice Kennedy Shriver National Institute of Child Health and Human Development intramural Summer Student Program (S.A.M.), Bethesda, Maryland 20892.

The cAMP-dependent protein kinase A (PKA) signaling system is widely expressed and has a central role in regulating cellular metabolism in all organ systems affected by obesity. PKA has four regulatory (RIα, RIIα, RIβ, RIIβ) and four catalytic (Cα, Cβ, Cγ, Prkx) subunit isoforms that have tissue-specific expression profiles. In mice, knockout (KO) of RIIβ, the primary PKA regulatory subunit in adipose tissue or knockout of the catalytic subunit Cβ resulted in a lean phenotype that resists diet-induced obesity and associated metabolic complications. Here we report that the disruption of the ubiquitously expressed PKA RIIα subunit in mice (RIIαKO) confers resistance to diet-induced obesity, glucose intolerance, and hepatic steatosis. After 2-week high-fat diet exposure, RIIαKO mice weighed less than wild-type littermates. Over time this effect was more pronounced in female mice that were also leaner than their wild-type counterparts, regardless of the diet. Decreased intake of a high-fat diet contributed to the attenuated weight gain in RIIαKO mice. Additionally, RIIα deficiency caused differential regulation of PKA in key metabolic organs: cAMP-stimulated PKA activity was decreased in liver and increased in gonadal adipose tissue. We conclude that RIIα represents a potential target for therapeutic interventions in obesity, glucose intolerance, and nonalcoholic fatty liver disease.
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http://dx.doi.org/10.1210/en.2014-1122DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4138573PMC
September 2014

Macronodular adrenal hyperplasia due to mutations in an armadillo repeat containing 5 (ARMC5) gene: a clinical and genetic investigation.

J Clin Endocrinol Metab 2014 Jun 6;99(6):E1113-9. Epub 2014 Mar 6.

Section on Endocrinology and Genetics (F.R.F., M.Z., M.B.L., E.S., G.T., A.B., C.A.S.), Program on Developmental Endocrinology and Genetics, Program on Reproductive and Adult Endocrinology (M.Z.), Biostatistics and Clinical Epidemiology Service (N.S.), Clinical Center, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892; Group for Advanced Molecular Investigation (F.R.F.), Graduate Program in Health Science, Center for Biological and Sciences, Pontificia Universidade Catolica do Paraná, Curitiba Brazil 80215-901; Department of Endocrinology, Metabolism, and Cancer (R.L., G.A., S.E., L.D., B.R., J.B.), INSERM Unité 1016, Centre National de la Recherche Scientifique Unité Mixte de Recherche 8104, Institut Cochin, 75014 Paris, France.

Context: Inactivating germline mutations of the probable tumor suppressor gene, armadillo repeat containing 5 (ARMC5), have recently been identified as a genetic cause of macronodular adrenal hyperplasia (MAH).

Objective: We searched for ARMC5 mutations in a large cohort of patients with MAH. The clinical phenotype of patients with and without ARMC5 mutations was compared.

Methods: Blood DNA from 34 MAH patients was genotyped using Sanger sequencing. Diurnal serum cortisol measurements, plasma ACTH levels, urinary steroids, 6-day Liddle's test, adrenal computed tomography, and weight of adrenal glands at adrenalectomy were assessed.

Results: Germline ARMC5 mutations were found in 15 of 34 patients (44.1%). In silico analysis of the mutations indicated that seven (20.6%) predicted major implications for gene function. Late-night cortisol levels were higher in patients with ARMC5-damaging mutations compared with those without and/or with nonpathogenic mutations (14.5 ± 5.6 vs 6.7 ± 4.3, P < .001). All patients carrying a pathogenic ARMC5 mutation had clinical Cushing's syndrome (seven of seven, 100%) compared with 14 of 27 (52%) of those without or with mutations that were predicted to be benign (P = .029). Repeated-measures analysis showed overall higher urinary 17-hydroxycorticosteroids and free cortisol values in the patients with ARMC5-damaging mutations during the 6-day Liddle's test (P = .0002).

Conclusions: ARMC5 mutations are implicated in clinically severe Cushing's syndrome associated with MAH. Knowledge of a patient's ARMC5 status has important clinical implications for the diagnosis of Cushing's syndrome and genetic counseling of patients and their families.
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http://dx.doi.org/10.1210/jc.2013-4280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4037724PMC
June 2014

Constitutive activation of PKA catalytic subunit in adrenal Cushing's syndrome.

N Engl J Med 2014 Mar 26;370(11):1019-28. Epub 2014 Feb 26.

The authors' affiliations are listed in the Appendix.

Background: Corticotropin-independent Cushing's syndrome is caused by tumors or hyperplasia of the adrenal cortex. The molecular pathogenesis of cortisol-producing adrenal adenomas is not well understood.

Methods: We performed exome sequencing of tumor-tissue specimens from 10 patients with cortisol-producing adrenal adenomas and evaluated recurrent mutations in candidate genes in an additional 171 patients with adrenocortical tumors. We also performed genomewide copy-number analysis in 35 patients with cortisol-secreting bilateral adrenal hyperplasias. We studied the effects of these genetic defects both clinically and in vitro.

Results: Exome sequencing revealed somatic mutations in PRKACA, which encodes the catalytic subunit of cyclic AMP-dependent protein kinase (protein kinase A [PKA]), in 8 of 10 adenomas (c.617A→C in 7 and c.595_596insCAC in 1). Overall, PRKACA somatic mutations were identified in 22 of 59 unilateral adenomas (37%) from patients with overt Cushing's syndrome; these mutations were not detectable in 40 patients with subclinical hypercortisolism or in 82 patients with other adrenal tumors. Among 35 patients with cortisol-producing hyperplasias, 5 (including 2 first-degree relatives) carried a germline copy-number gain (duplication) of the genomic region on chromosome 19 that includes PRKACA. In vitro studies showed impaired inhibition of both PKA catalytic subunit mutants by the PKA regulatory subunit, whereas cells from patients with germline chromosomal gains showed increased protein levels of the PKA catalytic subunit; in both instances, basal PKA activity was increased.

Conclusions: Genetic alterations of the catalytic subunit of PKA were found to be associated with human disease. Germline duplications of this gene resulted in bilateral adrenal hyperplasias, whereas somatic PRKACA mutations resulted in unilateral cortisol-producing adrenal adenomas. (Funded by the European Commission Seventh Framework Program and others.).
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http://dx.doi.org/10.1056/NEJMoa1310359DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4727447PMC
March 2014

Expression of the murine transcription factor SOX3 during embryonic and adult neurogenesis.

Gene Expr Patterns 2013 Oct 9;13(7):240-8. Epub 2013 May 9.

Discipline of Biochemistry, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, Australia.

Previous studies have shown that Sox3 is expressed in nascent neuroprogenitor cells and is functionally required in mammals for development of the dorsal telencephalon and hypothalamus. However, Sox3 expression during embryonic and adult neurogenesis has not been examined in detail. Using a SOX3-specific antibody, we show that murine SOX3 expression is maintained throughout telencephalic neurogenesis and is restricted to progenitor cells with neuroepithelial and radial glial morphologies. We also demonstrate that SOX3 is expressed within the adult neurogenic regions and is coexpressed extensively with the neural stem cell marker SOX2 indicating that it is a lifelong marker of neuroprogenitor cells. In contrast to the telencephalon, Sox3 expression within the developing hypothalamus is upregulated in developing neurons and is maintained in a subset of differentiated hypothalamic cells through to adulthood. Together, these data show that Sox3 regulation is region-specific, consistent with it playing distinct biological roles in the dorsal telencephalon and hypothalamus.
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http://dx.doi.org/10.1016/j.gep.2013.04.004DOI Listing
October 2013

Succinate dehydrogenase mutation underlies global epigenomic divergence in gastrointestinal stromal tumor.

Cancer Discov 2013 Jun 2;3(6):648-57. Epub 2013 Apr 2.

National Cancer Institute-Center for Cancer Research, Bethesda, MD 20892-4265, USA.

Gastrointestinal stromal tumors (GIST) harbor driver mutations of signal transduction kinases such as KIT, or, alternatively, manifest loss-of-function defects in the mitochondrial succinate dehydrogenase (SDH) complex, a component of the Krebs cycle and electron transport chain. We have uncovered a striking divergence between the DNA methylation profiles of SDH-deficient GIST (n = 24) versus KIT tyrosine kinase pathway-mutated GIST (n = 39). Infinium 450K methylation array analysis of formalin-fixed paraffin-embedded tissues disclosed an order of magnitude greater genomic hypermethylation relative to SDH-deficient GIST versus the KIT-mutant group (84.9 K vs. 8.4 K targets). Epigenomic divergence was further found among SDH-mutant paraganglioma/pheochromocytoma (n = 29), a developmentally distinct SDH-deficient tumor system. Comparison of SDH-mutant GIST with isocitrate dehydrogenase-mutant glioma, another Krebs cycle-defective tumor type, revealed comparable measures of global hypo- and hypermethylation. These data expose a vital connection between succinate metabolism and genomic DNA methylation during tumorigenesis, and generally implicate the mitochondrial Krebs cycle in nuclear epigenomic maintenance.
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http://dx.doi.org/10.1158/2159-8290.CD-13-0092DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4135374PMC
June 2013

Ultra-structural identification of interstitial cells of Cajal in the zebrafish Danio rerio.

Cell Tissue Res 2012 Aug 25;349(2):483-91. Epub 2012 May 25.

Section on Endocrinology & Genetics, Program on Developmental Endocrinology & Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Building 10, CRC, Room 1-3330, 10 Center Drive, MSC1103, Bethesda, MD 20892, USA.

The interstitial cells of Cajal (ICCs) are important mediators of gastrointestinal (GI) motility because of their role as pacemakers in the GI tract. In addition to their function, ICCs are also structurally distinct cells most easily identified by their ultra-structural features and expression of the tyrosine kinase receptor c-KIT. ICCs have been described in mammals, rodents, birds, reptiles, and amphibians, but there are no reports at the ultra-structural level of ICCs within the GI tract of an organism from the teleost lineage. We describe the presence of cells in the muscularis of the zebrafish intestine; these cells have similar features to ICCs in other vertebrates. The ICC-like cells are associated with the muscularis, are more electron-dense than surrounding smooth muscle cells, possess long cytoplasmic processes and mitochondria, and are situated opposing enteric nervous structures. In addition, immunofluorescent and immunoelectron-microscopic studies with antibodies targeting the zebrafish ortholog of a putative ICC marker, c-KIT (kita), showed c-kit immunoreactivity in zebrafish ICCs. Taken together, these data represent the first ultra-structural characterization of cells in the muscularis of the zebrafish Danio rerio and suggest that ICC differentiation in vertebrate evolution dates back to the teleost lineage.
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http://dx.doi.org/10.1007/s00441-012-1434-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3674513PMC
August 2012

Molecular genetics of the developing neuroendocrine hypothalamus.

Mol Cell Endocrinol 2010 Jul 10;323(1):115-23. Epub 2010 Apr 10.

Discipline of Physiology, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, Australia.

Formation of the mammalian endocrine system and neuroendocrine organs involves complex regulatory networks resulting in a highly specialized cell system able to secrete a diverse array of peptide hormones. The hypothalamus is located in the mediobasal region of the brain and acts as a gateway between the endocrine and nervous systems. From an endocrinology perspective, the parvicellular neurons of the hypothalamus are of particular interest as they function as a control centre for several critical physiological processes including growth, metabolism and reproduction by regulating hormonal signaling from target cognate cell types in the anterior pituitary. Delineating the genetic program that controls hypothalamic development is essential for complete understanding of parvicellular neuronal function and the etiology of congenital disorders that result from hypothalamic-pituitary axis dysfunction. In recent years, studies have shed light on the interactions between signaling molecules and activation of transcription factors that regulate hypothalamic cell fate commitment and terminal differentiation. The aim of this review is to summarize the recent molecular and genetic findings that have advanced our understanding of the emergence of the known important hypophysiotropic signaling molecules in the hypothalamus. We have focused on reviewing the literature that provides evidence of the dependence on expression of specific genes for the normal development and function of the cells that secrete these neuroendocrine factors, as well as studies of the elaboration of the spatial or temporal patterns of changes in gene expression that drive this development.
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http://dx.doi.org/10.1016/j.mce.2010.04.002DOI Listing
July 2010

Hypothalamic input is required for development of normal numbers of thyrotrophs and gonadotrophs, but not other anterior pituitary cells in late gestation sheep.

J Physiol 2008 Feb 20;586(4):1185-94. Epub 2007 Dec 20.

Discipline of Physiology, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, Australia.

To evaluate the hypothalamic contribution to the development of anterior pituitary (AP) cells we surgically disconnected the hypothalamus from the pituitary (hypothalamo-pituitary disconnection, HPD) in fetal sheep and collected pituitaries 31 days later. Pituitaries (n = 6 per group) were obtained from fetal sheep (term = 147 +/- 3 days) at 110 days (unoperated group) of gestation and at 141 days from animals that had undergone HPD or sham surgery at 110 days. Cells were identified by labelling pituitary sections with antisera against the six AP hormones. Additionally, we investigated the colocalization of glycoprotein hormones. The proportions of somatotrophs and corticotrophs were unchanged by age or HPD. Lactotrophs increased 80% over time, but the proportion was unaffected by HPD. Thyrotrophs, which were unaffected by age, increased 70% following HPD. Gonadotrophs increased with gestational age (LH+ cells 55%; FSH+ cells 19-fold), but this was severely attenuated by HPD. We investigated the possible existence of a reciprocal effect of HPD on multipotential glycoprotein-expressing cells. Co-expression of LH and TSH was extremely rare (< 1%) and unchanged over the last month of gestation or HPD. The increase of gonadotrophs expressing FSH only or LH and FSH was attenuated by HPD. Therefore, the proportions of somatotrophs, lactotrophs and corticotrophs are regulated independently of hypothalamic input in the late gestation fetal pituitary. In marked contrast, the determination of the thyrotroph and gonadotroph lineages over the same time period is subject to complex mechanisms involving hypothalamic factors, which inhibit differentiation and/or proliferation of thyrotrophs, but stimulate gonadotrophs down the FSH lineage. Development of a distinct population of gonadotrophs, expressing only LH, appears to be subject to alternative mechanisms.
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http://dx.doi.org/10.1113/jphysiol.2007.141523DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2375652PMC
February 2008