[Show abstract][Hide abstract] ABSTRACT: Telomere dysfunction and telomerase activation underlie cancer transformation. This study aims to investigate the contribution of telomere biology to pituitary tumor behavior.
Samples from 50 patients with pituitary tumors (11 ACTH-secreting, 18 GH-secreting, and 21 non-secreting tumors) and 7 subjects without pituitary lesions were collected. The expressions of telomerase essential components TERT and TERC and tumor telomere content were measured by quantitative PCR techniques.
Telomerase (TERT) expression was detected in 36 % of tumors. No correlation was observed between TERT and TERC expression level and tumor size in any tumor type. There was no association between gene expression and clinical findings. Telomere content (T/S ratio) was similar between pituitary adenomas (0.39 ± 0.16) and normal pituitaries (0.47 ± 0.12; p = 0.24) and also was between the different adenoma types: ACTH-secreting (0.43 ± 0.08), GH-secreting (0.31 ± 0.12), and non-secreting (0.42 ± 0.20; p = 0.10) tumors.
The telomere content and expression of telomerase components are comparable between normal pituitary glands and tumor tissues, suggesting that telomere biology does not play an important role in pituitary tumor development.
Journal of endocrinological investigation 05/2015; DOI:10.1007/s40618-015-0298-3 · 1.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Maternal kangaroo care (MKC) is a naturalistic intervention that alleviates neonatal pain, and mothers are assumed to play a stress regulatory role in MKC. Yet, no MKC infant pain study has examined relationship between maternal and infant stress reactivity concurrently, or whether post-partum depression and/or anxiety (PPDA) alters maternal and neonatal stress response and the regulatory effects of MKC.Objectives
To examine the concordance of salivary cortisol reactivity between 42 mothers and their stable preterm infants during routine infant heel lance (HL) while in MKC and to compare salivary cortisol between groups of mothers with and without PPDA and their infants.Methods
Maternal and infant salivary cortisol samples were collected pre-HL and 20 min post-HL with two additional maternal samples at night and in the morning. Mothers and infants were allocated to with PPDA versus without PPDA study groups on the basis of maternal post-natal mental health assessment scores.ResultsHigher mothers' cortisol pre-HL was weakly associated with higher infants' salivary cortisol in response to the HL procedure. Maternal depression and/or anxiety were not associated with infants' cortisol. During HL, both groups of mothers and infants showed no change in salivary cortisol.Conclusions
Concordance between mother and infant salivary cortisol supports the maternal stress regulatory role in MKC. MKC may have stress regulatory benefits for mothers and their preterm infants during HL independent of PPDA. Future MKC studies that target mothers with altered mood will help to build on these findings.
European journal of pain (London, England) 03/2015; 19(3). DOI:10.1002/ejp.566 · 3.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives: Pituitary stem cells play a role in the oncogenesis of human adamantinomatous craniopharyngiomas (aCPs). We hypothesized that crosstalk between the Wnt/beta-catenin and Sonic Hedgehog (SHH) pathways, both of which are important in normal pituitary development, would contribute to the pathogenesis of aCPs. Design: To explore the mRNA and protein expression of components of the SHH signaling pathway in aCPs and their relationship with the identification of CTNNB1/beta-catenin mutations and patients outcomes. Patients & Methods: In 18 aCP samples, CTNNB1 was sequenced, and the mRNA expression levels of SHH pathway members (SHH, PTCH1, SMO, GLI1, GLI2, GLI3 and SUFU) and SMO, GLI1, GLI3, SUFU, beta-catenin, and Ki67 proteins were evaluated by qPCR and immunohistochemistry, respectively. Anterior normal pituitaries were used as controls. Associations between molecular findings and clinical data were analyzed. Results: The aCPs presented higher mRNA expression of SHH (+400-fold change [FC]; P<0.01), GLI1 (+102-FC; P<0.001) and GLI3 (+5.1-FC; P<0.01) than normal anterior pituitaries. Longer disease-free survival was associated with low SMO and SUFU mRNA expression (P<0.01 and P=0.02, respectively). CTNNB1/beta-catenin mutations were found in 47% of the samples. aCPs with identified mutations presented with higher mRNA expression of SMO and GLI1 (+4.3-FC; P=0.02 and +10.2-FC; P=0.03, respectively). SMO, GLI1, GLI3, and SUFU staining was found in 85%, 67%, 93%, and 64% of the samples, respectively. Strong GLI1 and GLI3 staining was detected in palisade cells, which also labeled Ki67, a marker of cell proliferation. Conclusions: The upregulation of SHH signaling occurs in aCPs. Thus, activation of Wnt/beta-catenin and SHH pathways, both of which are important in pituitary embryogenesis, appears to contribute to the pathogenesis of aCP.
European Journal of Endocrinology 02/2015; 172(5). DOI:10.1530/EJE-14-0934 · 3.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Context and Objective
Sonic Hedgehog (SHH) and GLI2, an obligatory mediator of SHH signal transduction, are holoprosencephaly (HPE)-associated genes essential in pituitary formation. GLI2 variants have been found in patients with congenital hypopituitarism without complex midline cerebral defects (MCD). However, data on the occurrence of SHH mutations in these patients are limited. We screened for SHH and GLI2 mutations or copy number variations (CNV) in patients with congenital hypopituitarism without MCD or with variable degrees of MCD.Patients and methodsDetailed data on clinical, laboratory and neuroimaging findings of 115 patients presenting with congenital hypopituitarism without MCD, septo-optic dysplasia or HPE were analyzed. The SHH and GLI2 genes were directly sequenced and the presence of gene CNV was analyzed by multiplex ligation-dependent probe amplification (MLPA).ResultsAnterior pituitary deficiency was found in 74% and 53% of patients with SOD or HPE, respectively. Diabetes insipidus was common in patients with HPE (47%) but infrequent in patients with congenital hypopituitarism or SOD (7% and 8%, respectively). A single heterozygous nonsense SHH mutation (p.Tyr175Ter) was found in a patient presenting with hypopituitarism and alobar HPE. No other SHH mutations or CNV were found. Nine GLI2 variations (8 missense and 1 frameshift) including a homozygous and a compound heterozygous variation were found in patients with congenital hypopituitarism or SOD but not in HPE patients. No GLI2 CNV were found.ConclusionSHH mutations or CNV are not a common cause of congenital hypopituitarism in patients without complex MCD. GLI2 variants are found in some patients with congenital hypopituitarism without complex MCD or SOD. However, functional analyses of these variants are needed to strengthen genotype-phenotype relationship.This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Background: The sonic hedgehog (SHH) pathway plays a key role in rodent adrenal cortex development and is involved in tumorigenesis in several human tissues, but data in human adrenal glands are limited. Objectives: To analyze the involvement of the SHH pathway in human adrenal development and tumorigenesis and the effects of SHH inhibition on an adrenocortical tumor (ACT) cell line. Patients & Methods: Expression of SHH pathway components was evaluated by immunohistochemistry (IHC) in 51 normal adrenals (33 fetal) and 34 ACTs (23 pediatric), and by qPCR in 81 ACTs (61 pediatric) and 19 controls (10 pediatric). The effects of SHH pathway inhibition on gene expression and cell viability in the NCI-H295A adrenocortical tumor cell line after cyclopamine treatment were analyzed. Results: SHH pathway proteins were present in fetal and postnatal normal adrenals and showed distinct patterns of spatiotemporal expression throughout development. Adult ACCs presented with higher expression of PTCH1, SMO, GLI3 and SUFU compared with normal adult adrenal cortices. Conversely, pediatric ACTs showed lower mRNA expression of SHH, PTCH1, SMO, GLI1 and GLI3 compared with normal pediatric adrenal cortices. In vitro treatment with cyclopamine resulted in decreased GLI3, SFRP1, CTNNB1 mRNA expression and beta-catenin staining, as well as decreased cell viability. Conclusions: The SHH pathway is active in human fetal and postnatal adrenals, up regulated in adult ACCs and down regulated in pediatric ACTs. SHH pathway antagonism impaired cell viability. The SHH pathway is deregulated in ACTs and might provide a new target therapy to be explored.
The Journal of Clinical Endocrinology and Metabolism 04/2014; 99(7):jc20134098. DOI:10.1210/jc.2013-4098 · 6.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ContextThe role of planar cell polarity (Wnt/PCP) and calcium-dependent (Wnt/Ca) noncanonical Wnt pathways in adrenocortical tumours (ACTs) is unknown.Objectives
To investigate gene expression of Wnt/PCP and Wnt/Ca pathways and its association with TP53 p.R337H and CTNNB1 mutations in paediatric and adult ACTs and to correlate these findings with clinical outcome.PatientsExpression of noncanonical Wnt-related genes was evaluated in 91 ACTs (66 children, 25 adults) by qPCR and beta-catenin, P53, and protein effectors of Wnt/Ca (NFAT) and Wnt/PCP (JNK) by immunohistochemistry. TP53 and CTNNB1 genes were sequenced.ResultsTP53 p.R337H mutation frequency was higher in children (86% vs 28%) while CTNNB1 mutation was higher in adults (32% vs 6%). Mortality was higher in adults harbouring TP53 p.R337H and in children with CTNNB1 mutations. Overexpression of WNT5A, Wnt/Ca ligand, was observed in children and adults. Overexpression of MAPK8 and underexpression of PRICKLE, Wnt/PCP mediators, were observed in paediatric, but not in adult cases. Cytoplasmic/nuclear beta-catenin and P53 accumulation were observed in the majority of pediatric and adult ACTs as well as NFAT and JNK. Overexpression of MAPK8 and underexpression of PRICKLE were associated with mortality in children while overexpression of WNT5A and underexpression of PRICKLE were associated with mortality in adults.Conclusions
In our study, TP53 p.R337H and CTNNB1 mutations correlated with poor prognosis in adults and children, respectively. We demonstrate, for the first time, the activation of Wnt/PCP and Wnt/Ca noncanonical pathway genes, and their association with poor outcome in children and adults, suggesting their putative involvement in ACTs aggressiveness.This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Context: Loss-of-function mutations in makorin ring finger 3 (MKRN3), an imprinted gene located on the long arm of chromosome 15, have been recognized recently as a cause of familial central precocious puberty (CPP) in humans. MKRN3 has a potential inhibitory effect on GnRH secretion. Objectives: To investigate potential MKRN3 sequence variations as well as copy number and methylation abnormalities of the 15q11 locus in patients with apparently sporadic CPP. Setting and participants: We studied 215 unrelated children (207 girls and 8 boys) from three University Medical Centers with a diagnosis of CPP. All but two of these patients (213 cases) reported no family history of premature sexual development. First-degree relatives of patients with identified MKRN3 variants were included for genetic analysis. Main Outcome Measures: All 215 CPP patients were screened for MKRN3 mutations by automatic sequencing. Multiplex ligation-dependent probe amplification was performed in a partially overlapping cohort of 52 patients. Results: We identified five novel heterozygous mutations in MKRN3 in eight unrelated girls with CPP. Four were frameshift mutations predicted to encode truncated proteins and one was a missense mutation, which was suggested to be deleterious by in silico analysis. All patients with MKRN3 mutations had classical features of CPP with a median age of onset at 6 years. Copy number and methylation abnormalities at the 15q11 locus were not detected in the patients tested for these abnormalities. Segregation analysis was possible in 5 of the 8 girls with MKRN3 mutations; in all cases, the mutation was inherited on the paternal allele. Conclusions: We have identified novel inherited MKRN3 defects in children with apparently sporadic CPP, supporting a fundamental role of this peptide in the suppression of the reproductive axis.
The Journal of Clinical Endocrinology and Metabolism 03/2014; 99(6):jc20133126. DOI:10.1210/jc.2013-3126 · 6.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective : The Brazilian population has heterogeneous ethnicity. No previous study evaluated NR3C1 polymorphisms in a Brazilian healthy population. Materials and methods : We assessed NR3C1 polymorphisms in Brazilians of Caucasian, African and Asian ancestry (n = 380). In a subgroup (n = 40), we compared the genotypes to glucocorticoid (GC) sensitivity, which was previously evaluated by plasma (PF) and salivary (SF) cortisol after dexamethasone (DEX) suppression tests, GC receptor binding affinity (K d ), and DEX-50% inhibition (IC 50 ) of concanavalin-A-stimulated mononuclear cell proliferation. p.N363S (rs6195), p.ER22/23EK (rs6189-6190), and BclI (rs41423247) allelic discrimination was performed by Real-Time PCR (Polymerase Chain Reaction). Exons 3 to 9 and exon/intron boundaries were amplified by PCR and sequenced. Results : Genotypic frequencies (%) were: rs6195 (n = 380; AA:96.6/AG:3.14/GG:0.26), rs6189-6190 (n = 264; GG:99.6/GA:0.4), rs41423247 (n = 264; CC:57.9/CG:34.1/GG:8.0), rs6188 (n = 155; GG:69.6/GT:25.7/TT:4.7), rs258751 (n = 150; CC:88.0/CT:10.7/TT:1.3), rs6196 (n = 176; TT:77.2/TC:20.4/CC:2.4), rs67300719 (n = 137; CC:99.3/CT:0.7), and rs72542757 (n = 137; CC:99.3/CG:0.7). The rs67300719 and rs72542757 were found only in Asian descendants, in whom p.N363S and p.ER22/23EK were absent. The p.ER22/23EK was observed exclusively in Caucasian descendants. Hardy-Weinberg equilibrium was observed, except in the Asian for rs6188 and rs258751, and in the African for p.N363S. The K d , IC 50 , baseline and after DEX PF or SF did not differ between genotype groups. However, the mean DEX dose that suppressed PF or SF differed among the BclI genotypes (P = 0.03). DEX dose was higher in GG- (0.7 ± 0.2 mg) compared to GC- (0.47 ± 0.2 mg) and CC-carriers (0.47 ± 0.1 mg). Conclusion : The genotypic frequencies of NR3C1 polymorphisms in Brazilians are similar to worldwide populations. Additionally, the BclI polymorphism was associated with altered pituitary-adrenal axis GC sensitivity.
Arquivos brasileiros de endocrinologia e metabologia 02/2014; 58(1):53-61. DOI:10.1590/0004-2730000002868 · 0.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Canonical and non-canonical Wnt pathways are involved in the genesis of multiple tumors; however, their role in pituitary tumorigenesis is mostly unknown.
This study evaluated gene and protein expression of Wnt pathways in pituitary tumors and whether these expression correlate to clinical outcome.
GENES OF THE WNT CANONICAL PATHWAY: activating ligands (WNT11, WNT4, WNT5A), binding inhibitors (DKK3, sFRP1), β-catenin (CTNNB1), β-catenin degradation complex (APC, AXIN1, GSK3β), inhibitor of β-catenin degradation complex (AKT1), sequester of β-catenin (CDH1), pathway effectors (TCF7, MAPK8, NFAT5), pathway mediators (DVL-1, DVL-2, DVL-3, PRICKLE, VANGL1), target genes (MYB, MYC, WISP2, SPRY1, TP53, CCND1); calcium dependent pathway (PLCB1, CAMK2A, PRKCA, CHP); and planar cell polarity pathway (PTK7, DAAM1, RHOA) were evaluated by QPCR, in 19 GH-, 18 ACTH-secreting, 21 non-secreting (NS) pituitary tumors, and 5 normal pituitaries. Also, the main effectors of canonical (β-catenin), planar cell polarity (JNK), and calcium dependent (NFAT5) Wnt pathways were evaluated by immunohistochemistry.
There are no differences in gene expression of canonical and non-canonical Wnt pathways between all studied subtypes of pituitary tumors and normal pituitaries, except for WISP2, which was over-expressed in ACTH-secreting tumors compared to normal pituitaries (4.8x; p = 0.02), NS pituitary tumors (7.7x; p = 0.004) and GH-secreting tumors (5.0x; p = 0.05). β-catenin, NFAT5 and JNK proteins showed no expression in normal pituitaries and in any of the pituitary tumor subtypes. Furthermore, no association of the studied gene or protein expression was observed with tumor size, recurrence, and progressive disease. The hierarchical clustering showed a regular pattern of genes of the canonical and non-canonical Wnt pathways randomly distributed throughout the dendrogram.
Our data reinforce previous reports suggesting no activation of canonical Wnt pathway in pituitary tumorigenesis. Moreover, we describe, for the first time, evidence that non-canonical Wnt pathways are also not mis-expressed in the pituitary tumors.
PLoS ONE 04/2013; 8(4):e62424. DOI:10.1371/journal.pone.0062424 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: CONTEXT: Molecular diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) has not been straightforward. OBJECTIVE: To conduct a comprehensive genetic analysis by Multiplex Ligation dependent Probe Amplification (MLPA) and evaluate its reliability for the molecular CAH-21OHD diagnosis. PATIENTS AND METHODS: We studied 99 patients from 90 families with salt-wasting (SW; n=32), simple-virilizing (SV; n=29), and non-classical (NC; n=29) CAH-21OHD. Molecular analysis was sequentially performed by detecting the most frequent point mutations by allele-specific oligonucleotide polymerase chain reaction (ASO-PCR), large rearrangements by MLPA, and rare mutations by direct sequencing. Parental segregation was evaluated. RESULTS: ASO-PCR detected microconversions in 164 alleles (91.1%). MLPA identified CYP21A1P large conversions to CYP21A2 in 7 of the remaining 16 (43.7%), 30-kb deletions including the 3´-end of CYP21A1P, C4B, and the 5´-end of CYP21A2 in 3 of the 16 (18.7%), and a complete CYP21A2 deletion in one (6.3%). Five alleles (2.7%) required direct sequencing; three mutations located in the CYP21A2 gene and two derived from CYP21A1P were found. No parental segregation was observed in patients with the c.329_336del and/or the CL6 cluster mutations. These cases were not diagnosed by ASO-PCR, but MLPA detected deletions in the promoter region of the CYP21A2 gene, explaining the genotype/phenotype dissociation. CONCLUSION: Using the proposed algorithm, all alleles were elucidated. False-positive results in MLPA occurred when mutations or polymorphisms were located close to the probe-binding regions. These difficulties were overcome by the association of MLPA with ASO-PCR and paternal segregation. Using these approaches, we can successfully use MLPA in a cost-effective laboratory routine for the molecular diagnosis of CAH-21OHD.
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION: Cortisol Awakening Response (CAR) is a rapid increase of cortisol levels within 30-45 min after awakening. Objective: This study evaluates CAR compared to cortisol circadian rhythm in active and in remission Cushing´s disease (CD). Material and Methods: We evaluated healthy controls (HC, n=19), obese (OB, n=10), in remission (n=08), and active CD patients (n=10). Salivary cortisol (SF) was determined at 0800, 1100, 1700, 2000 and 2300h on the first day. CAR was obtained in the next morning immediately upon awakening and at 15, 30, 45, and 60 min post-wake-up. Results: We observed differences in SF levels throughout the day in HC, OB, and in remission CD (ANOVA P=0.0001), but not in active CD (P=0.2). We demonstrated SF increment after awakening in HC, OB, and in remission CD (ANOVA P=0.007), with no effect of time on SF in active CD. The relative increment of SF obtained at the peak after awakening (CARi%) in the active CD (67±57%) was lower than in HC (154±107%), OB (240±188%) and in remission CD (186±184%) patients (P=0.009). There was a negative correlation between the SF at awakening and the CARi% in HC (r=-0.8), OB (r=-0.78), and in remission CD (r=-0.74), but not in active CD (r=-0.35; P=0.31). Conclusion: The present study originally described a blunted CAR in active CD in contrast to its presence in HC, OB, and in remission CD. This subtle dysfunction of the HPA axis may represent a distinct and additional physiopathological phenomenon superimposing the dysregulated cortisol circadian rhythm in this disease.
European Journal of Endocrinology 02/2013; DOI:10.1530/EJE-12-0982 · 3.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: To estimate the pretest probability of Cushing's syndrome (CS) diagnosis by a Bayesian approach using intuitive clinical judgment. MATERIALS AND METHODS: Physicians were requested, in seven endocrinology meetings, to answer three questions: "Based on your personal expertise, after obtaining clinical history and physical examination, without using laboratorial tests, what is your probability of diagnosing Cushing's Syndrome?"; "For how long have you been practicing Endocrinology?"; and "Where do you work?". A Bayesian beta regression, using the WinBugs software was employed. RESULTS: We obtained 294 questionnaires. The mean pretest probability of CS diagnosis was 51.6% (95%CI: 48.7-54.3). The probability was directly related to experience in endocrinology, but not with the place of work. CONCLUSION: Pretest probability of CS diagnosis was estimated using a Bayesian methodology. Although pretest likelihood can be context-dependent, experience based on years of practice may help the practitioner to diagnosis CS. Arq Bras Endocrinol Metab. 2012;56(9):633-7.
Arquivos brasileiros de endocrinologia e metabologia 12/2012; 56(9):633-637. DOI:10.1590/S0004-27302012000900006 · 0.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ALTHOUGH THE MOLECULAR PATHOGENESIS OF PITUITARY ADENOMAS HAS BEEN ASSESSED BY SEVERAL DIFFERENT TECHNIQUES, IT STILL REMAINS PARTIALLY UNCLEAR. RIBOSOMAL PROTEINS (RP) HAVE BEEN RECENTLY RELATED TO HUMAN TUMORIGENESIS, BUT THEY HAVE NOT YET BEEN EVALUATED IN PITUITARY TUMORIGENESIS. OBJECTIVE THE AIM OF THIS STUDY WAS TO INTRODUCE SAGE (SERIAL ANALYSIS OF GENE EXPRESSION), A HIGH-THROUGHPUT METHOD, IN PITUITARY RESEARCH IN ORDER TO COMPARE DIFFERENTIAL GENE EXPRESSION. METHODS TWO SAGE CDNA LIBRARIES WERE CONSTRUCTED, ONE USING A POOL OF MRNA OBTAINED FROM FIVE GH-SECRETING PITUITARY TUMORS AND ANOTHER FROM THREE NORMAL PITUITARIES. GENES DIFFERENTIALLY EXPRESSED BETWEEN THE LIBRARIES WERE FURTHER VALIDATED BY REAL TIME PCR IN TWENTY-TWO GH-SECRETING PITUITARY TUMORS AND IN FIFTEEN NORMAL PITUITARIES. RESULTS COMPUTER GENERATED GENOMIC ANALYSIS TOOLS IDENTIFIED 13,722 AND 14,993 EXCLUSIVE GENES IN NORMAL AND ADENOMA LIBRARIES, RESPECTIVELY. BOTH SHARED 6,497 GENES: 2,188 were underexpressed and 4,309 overexpressed in tumoral library. In adenoma library, 33 genes encoding ribosomal proteins were underexpressed. Among these, RPSA, RPS3, RPS14, and RPS29 were validated by Real-Time PCR. Conclusion We report the first SAGE library from normal pituitary tissue and GH-secreting pituitary tumor, which provide quantitative assessment of cellular transcriptome. We also validated some down-regulated genes encoding ribosomal proteins. Altogether, the present data suggests that the underexpression of the studied RP genes possibly collaborates directly or indirectly with other genes to modify cell cycle arrest, DNA repair and apoptosis, leading to an environment that might have a putative role in the tumorigenesis, introducing new perspectives for further studies on molecular genesis of somatotrophinomas.
European Journal of Endocrinology 09/2012; DOI:10.1530/EJE-12-0760 · 3.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the modulation of the hypothalamus-pituitary-adrenal axis (HPA) on prolactin secretion in rats after adrenalectomy (ADX).
Plasma corticosterone, ACTH, and prolactin concentrations were measured by radioimmunoassay in rats after bilateral ADX in the short- (3 hours and 1 day) and long-term (3, 7, and 14 days).
Animals that underwent ADX showed undetectable corticosterone levels and a triphasic ACTH response with a transient increase (3h), a decrease (1d), and further increase in the long-term after ADX. Sham animals showed a marked increase in corticosterone and ACTH levels three hours after surgery, with a decrease to basal levels thereafter. Plasma prolactin levels were not changed after ADX.
There are different points of equilibrium in the HPA axis after the glucocorticoid negative feedback is removed. Prolactin plasma secretion is not altered in the short or long- term after ADX, suggesting that the peptidergic neurons essential for prolactin release are not activated after ADX.
Arquivos brasileiros de endocrinologia e metabologia 06/2012; 56(4):244-9. DOI:10.1590/S0004-27302012000400005 · 0.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Idiopathic central precocious puberty and its postponement with a (gonadotropin-releasing hormone) GnRH agonist are complex conditions, the final effects of which on bone mass are difficult to define. We evaluated bone mass, body composition, and bone remodeling in two groups of girls with idiopathic central precocious puberty, namely one group that was assessed at diagnosis and a second group that was assessed three years after GnRH agonist treatment.
The precocious puberty diagnosis and precocious puberty treatment groups consisted of 12 girls matched for age and weight to corresponding control groups of 12 (CD) and 14 (CT) girls, respectively. Bone mineral density and body composition were assessed by dual X-ray absorptiometry. Lumbar spine bone mineral density was estimated after correction for bone age and the mathematical calculation of volumetric bone mineral density. CONEP: CAAE-0311.0.004.000-06.
Lumbar spine bone mineral density was slightly increased in individuals diagnosed with precocious puberty compared with controls; however, after correction for bone age, this tendency disappeared (CD = -0.74 + 0.9 vs. precocious puberty diagnosis = -1.73 + 1.2). The bone mineral density values of girls in the precocious puberty treatment group did not differ from those observed in the CT group.
There is an increase in bone mineral density in girls diagnosed with idiopathic central precocious puberty. Our data indicate that the increase in bone mineral density in girls with idiopathic central precocious puberty is insufficient to compensate for the marked advancement in bone age observed at diagnosis. GnRH agonist treatment seems to have no detrimental effect on bone mineral density.
[Show abstract][Hide abstract] ABSTRACT: CTNNB1/β-catenin mutations and activation of Wnt/β-catenin pathway are frequent in adult adrenocortical tumors (ACT), but data on childhood ACT are lacking.
The aim of the study was to investigate the presence of Wnt/β-catenin pathway abnormalities in childhood ACT.
Clinicopathological findings and outcome of 62 childhood ACT patients were analyzed regarding CTNNB1 mutations and the expression of Wnt-related genes (CTNNB1; WNT4, a Wnt ligand; SFRP1, DKK3, and AXIN1, Wnt inhibitors; TCF7, a transcription factor; and MYC and WISP2, target genes) by quantitative PCR and immunohistochemistry.
CTNNB1-activating mutations were found in only four of 62 ACT (6%), all of them harboring TP53 mutation. There was association between the presence of CTNNB1 mutations and death (P = 0.02). Diffuse β-catenin accumulation was found in 71% of ACT, even in ACT without CTNNB1 mutations. Compared to normal adrenals, ACT presented increased expression of CTNNB1 (P = 0.008) and underexpression of Wnt inhibitor genes: DKK3 (P < 0.0001), SFRP1 (P = 0.05), and AXIN1 (P = 0.04). With regard to Wnt/β-catenin target genes, ACT presented increased expression of WISP2 but lower expression of MYC. Higher overall survival was associated with underexpression of SFRP1 (P = 0.01), WNT4 (P = 0.004), and TCF7 (P < 0.01).
CTNNB1 mutations are not common in childhood ACT but appear to associate with poor prognosis. Nevertheless, most ACT exhibit increased expression of β-catenin and WISP2 and reduced expression of Wnt inhibitor genes (DKK3, SFRP1, and AXIN1). Thus, in addition to CTNNB1 mutations, other genetic events affecting the Wnt/β-catenin pathway may be involved in childhood adrenocortical tumorigenesis.
The Journal of Clinical Endocrinology and Metabolism 08/2011; 96(10):3106-14. DOI:10.1210/jc.2011-0363 · 6.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The association between large for gestational age (LGA) phenotype, postnatal growth and cardiometabolic risk (CMR) in adult life remains unclear. The role of IGF1 genotype on LGA-related outcomes in adult life is unknown.
To assess the postnatal growth, IGF-I levels, CMR and the influence of the 737.738 IGF1 in adults born LGA.
Case-control study (n = 515) nested in a population-based prospective cohort (n = 2063); 117 LGA and 398 gender-matched controls appropriate for gestational age (AGA) subjects.
Anthropometry was evaluated at birth, at 9-10 and at 23-25 years old. At the age of 23-25 years, blood pressure (BP), glycaemia, insulinaemia, homeostasis model assessment - insulin resistance, lipids, fibrinogen, and plasma IGF-I and 737.738 IGF1 polymorphism were assessed.
Large for gestational age subjects remained heavier and taller than AGA at 9-10 and 23-25 years (P < 0·05); at 23-25 years, LGA had greater waist circumference (WC; P < 0·05) and higher BP (P < 0·05) than controls. Body proportionality at birth did not predict metabolic outcome. LGA subjects presenting catch-down of weight in childhood had lower body mass index (BMI; P = 0·001), lower WC (P < 0·05) and lower BP (P < 0·05) at 23-25 years. 737.738 IGF-I genotype differed between groups (P < 0·001). Homozygosis for polymorphic alleles was associated with increased odds of LGA (OR: 3·2; 95% CI: 1·5-6·9), higher IGF-I (56·9 ± 16·4 vs 37·7 ± 16·0 nm; P < 0·01) and lower BP (114/68 vs 121/73 mmHg; P < 0·05).
Young adults born LGA presented higher BMI, WC and BP and appear to be at higher CMR risk than AGA subjects. The 737.738 IGF1 polymorphism appears to play a role on birth size and LGA-related metabolic outcomes.
[Show abstract][Hide abstract] ABSTRACT: The corticotrophin releasing hormone (CRH), the main hypothalamic regulator of adrenocorticotropic hormone (ACTH) secretion,
is mainly synthesized in the parvocellular, but also in the magnocellular neurons, of the paraventricular nucleus (PVN). CRH
neurons of the PVN receive adrenergic afferent from nucleus tractus solitarius, locus coeruleus, and ventro-lateral medulla. CRH is secreted into the hypophyseal portal blood and binds to high affinity membrane type I
CRH receptors (CRH-R1) in the anterior pituitary corticotrophs to stimulate pro-opiomelanocortin (POMC) gene transcription
through a process that includes the activation of adenylyl cyclase. The CRH stimulates POMC gene transcription in vivo and
in vitro and also in response to stress and adrenalectomy. ACTH, synthesized within the anterior pituitary as part of a large
POMC 241-amino-acid precursor, is the principal hormone stimulating adrenal glucocorticoid biosynthesis and secretion. Angiotensin
II, activin, inhibin, and cytokines (TNF-β and leptin) synergize with or inhibit the effects of ACTH on the adrenal cortex.
The hypothalamic pituitary adrenal (HPA) axis is also regulated by biological rhythms resulting from a complex interaction
of genetic output of the endogenous circadian pacemaker and environmental synchronizers. ACTH is secreted in a pulsatile pattern
with a circadian rhythm so that levels are the highest on waking and decline throughout the day, reaching the nadir values
in the evening. Other regulator of the HPA axis is the stress system, which has main components the CRH and locus coeruleus-norepinephrine
autonomic systems and their peripheral effectors. Basal and stress induced activity of the HPA axis is constrained by glucocorticoid
negative feedback. Glucocorticoids and catecholamines affect major immune functions such as antigen presentation, leukocyte
proliferation and traffic, secretion of cytokines and antibodies, and selection of the T helper (Th) 1 versus Th2 responses.
The proinflammatory cytokines, notably interleukin-1, interleukin-6, tumor necrosis factor β, and leukemia inhibitory factor
also increase ACTH secretion either directly or by augmenting the effect of CRF. Glucocorticoids exert an immunoregulatory
feedback by several mechanisms, involving the blockade of lymphocyte activation, the production and action of IL-2, IL-1,
γ-interferon, TNF, and prostaglandins. Another important aspect of the regulation of the HPA axis is the negative feedback
control exerted by glucocorticoid, which inhibits the basal expression of CRH and AVP mRNA synthesis and secretion in the
hypothalamus and also inhibits POMC gene transcription in the anterior pituitary. Glucocorticoid exerts its effects by activation
of cytosolic receptors that belong to the nuclear receptor superfamily, the corticosteroid type I, or mineralocorticoid, and
corticosteroid type II, or glucocorticoid, receptors. Several molecular mechanisms underlying glucocorticoid actions have
been elucidated, most of which involve transcriptional regulation of gene expression. One of the most important factors regulating
the access of endogenous glucocorticoid to its receptor is local metabolism of the steroids within the target cells by 11β-hydroxysteroid
dehydrogenase (11β-HSD) enzymes, a phenomenon sometimes termed prereceptor metabolism. Cortisol/corticosterone are responsible
for the salt and water homeostasis and blood pressure control and influence carbohydrate, protein, lipid, and bone metabolism.
They are also important regulators of immune and inflammatory processes and are required for numerous processes associated
with host defense. On the other hand, prolonged or high dose glucocorticoid therapy as well as an excess of endogenous production
of glucocorticoids exert a large spectrum of deleterious actions in the whole body. Our understanding on the HPA axis biology
has given significant insight into the critical role of glucocorticoids in the maintenance of homeostasis and, when dysregulated,
in the pathogenesis of diseases.
Key Words:Hypothalamic-pituitary-adrenal-axis-stress response-cortisol circadian rhythm-glucocorticoid feedback-pathophysiology
[Show abstract][Hide abstract] ABSTRACT: Genes involved in formation/development of the adenohypophysis, CTNNB1 gene, and microRNAs might be implicated in the craniopharyngioma pathogenesis. The objective of this study is to perform the molecular analysis of HESX1, PROP1, POU1F1, and CTNNB1 genes and evaluate a panel of miRNA expression in craniopharyngioma. We also verified whether the presence of CTNNB1 mutation is associated with clinical findings and miRNA expression. The study included 16 patients with adamantinomatous craniopharyngioma (nine children and seven adults; eight females and eight males; 6-55 years, median 15.5 years). DNA, RNA, and cDNA were obtained from craniopharyngioma and normal pituitaries. DNA was also extracted from peripheral blood of healthy subjects. All genes were amplified by polymerase chain reaction and direct sequenced. Relative quantification of miRNA expression was calculated using the 2(-ΔΔCt) method. We found no mutations in HESX1, PROP1, and POU1F1 genes and four polymorphisms in PROP1 gene which were in Hardy-Weinberg equilibrium and had similar allelic frequencies in craniopharyngioma and controls. We found seven different mutations in CTNNB1 in eight of 16 patients. Younger patients presented more frequently CTNNB1 mutation than adults. We observed hyperexpression of miR-150 (1.7-fold); no different expression of miR-16-1, miR-21, and miR23a; and an underexpression of miR-141, let-7a, miR-16, miR-449, miR-145, miR-143, miR-23b, miR-15a, and miR-24-2 (ranging from -7.5 to -2.5-fold; p = 0.02) in craniopharyngioma. There was no association between tumor size or the recurrence and the presence of CTNNB1mutations. miR-16 and miR-141 were underexpressed in craniopharyngioma presenting CTNNB1 mutations. miR-23a and miR24-2 were hyperexpressed in patients who underwent only one surgery. Mutations or polymorphisms in pituitary transcription factors are unlikely to contribute to the adamantinomatous craniopharyngioma pathogenesis, differently of CTNNB1 mutations. Our data suggest the potential involvement of the deregulation of miRNA expression in the craniopharyngioma pathogenesis and outcome and also that the miRNA could modulate the Wnt signaling pathway in craniopharyngioma tumorigenesis.
Hormones and Cancer 08/2010; 1(4):187-96. DOI:10.1007/s12672-010-0041-7 · 2.15 Impact Factor