ANA CLAUDIA LATRONICO XAVIER
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Clínica Médica, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/42 - Laboratório de Hormônios e Genética Molecular, Hospital das Clínicas, Faculdade de Medicina
11 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 11
- Kisspeptin and Clinical Disorders(2013) SILVEIRA, Leticia Gontijo; LATRONICO, Ana Claudia; SEMINARA, Stephanie BethThe hypothalamic hormone GnRH has traditionally been viewed as a central driver of the hypothalamic-pituitary-gonadal axis. Pulsatile GnRH release is required for pulsatile gonadotropin secretion, which then modulates gonadal steroid feedback and brings about full fertility in the adult. Pathways governing GnRH ontogeny and physiology have been discovered by studying humans with disorders of GnRH secretion. In this chapter, the human genetics of the kisspeptin signaling pathway in patients with diverse reproductive phenotypes will be explored. The discovery of defects in the kisspeptin system in several reproductive disorders has shed light on the mechanisms involved in regulating GnRH secretion, revealing the critical role played by the kisspeptin signaling pathway in pubertal initiation and reproductive function.
- The benign spectrum of hypothalamic hamartomas: Infrequent epilepsy and normal cognition in patients presenting with central precocious puberty(2013) CUKIER, Priscilla; CASTRO, Luiz Henrique Martins; BANASKIWITZ, Natalie; TELES, Leandro Roberto; FERREIRA, Luiz Roberto Kobuti; ADDA, Carla Cristina; LEITE, Claudia da Costa; ARNHOLD, Ivo J. P.; MENDONCA, Berenice Bilharinho; LATRONICO, Ana Claudia; BRITO, Vinicius NahimePurpose: Hypothalamic hamartoma (HH) is the main structural cause of central precocious puberty (CPP). HH is frequently associated with cognitive impairment and epileptic encephalopathies. Disease severity in case series from neurology services may be biased towards more neurologically impaired patients. Aim: To perform a prospective cognitive evaluation in patients with HH presenting with CPP in an endocrinology outpatient clinic setting. Methods: We evaluated fifteen consecutive patients with CPP due to HH presenting to an endocrinology outpatient clinic. CPP was diagnosed at a median age of 0.7 yr (0.4-7 yr). Mean age at neurologic evaluation was 13.9 yrs. Eight patients (53.3%) were male. Epileptic seizures occurred in 5/15 (33%) patients. Two patients presented a single unprovoked seizure (SUS). Three patients were diagnosed with epilepsy. Cognitive evaluation, using age-appropriate Wechsler Intelligence Scale, was performed in 11 patients. Results: All patients without epilepsy, including two patients with a history of a SUS, had normal neurologic and cognitive evaluation. Epilepsy and SUS were only seen in patients with sessile HH. Three patients with epilepsy presented cognitive or behavioral findings. Reduced intelligence quotients (IQ), in the borderline range, were noted in both patients with epilepsy who underwent full cognitive evaluation. We found no significant correlation between HH diameter or shape and mean full-scale IQ. Conclusions: Patients who presented with isolated CPP without epilepsy displayed normal cognition when evaluated after a mean period of 13 years. Occurrence of epilepsy, seen in a minority of patients, but not of a single seizure, was associated with mild cognitive deficit and behavioral disturbances in this case series.
- Molecular and Gene Network Analysis of Thyroid Transcription Factor 1 (TTF1) and Enhanced at Puberty (EAP1) Genes in Patients with GnRH-Dependent Pubertal Disorders(2013) CUKIER, Priscilla; WRIGHT, Hollis; RULFS, Tomke; SILVEIRA, Leticia Ferreira Gontijo; TELES, Milena Gurgel; MENDONCA, Berenice Bilharinho; ARNHOLD, Ivo J. P.; HEGER, Sabine; LATRONICO, Ana Claudia; OJEDA, Sergio R.; BRITO, Vinicius NahimeBackground/Aim: TTF1 and EAP1 are transcription factors that modulate gonadotropin-releasing hormone expression. We investigated the contribution of TTF1 and EAP1 genes to central pubertal disorders. Patients and Methods: 133 patients with central pubertal disorders were studied: 86 with central precocious puberty and 47 with normosmic isolated hypogonadotropic hypogonadism. The coding region of TTF1 and EAP1 were sequenced. Variations of polyglutamine and polyalanine repeats in EAP1 were analyzed by GeneScan software. Association of TTF1 and EAP1 to genes implicated in timing of puberty was investigated by meta-network framework GeneMANIA and Cytoscape software. Results: Direct sequencing of the TTF1 did not reveal any mutation or polymorphisms. Four EAP1 synonymous variants were identified with similar frequencies among groups. The most common EAP1 5'-distal polyalanine genotype was the homozygous 12/12, but the genotype 12/9 was identified in 2 central precocious puberty sisters without functional alteration in EAP1 transcriptional activity. TTF1 and EAP1 were connected, via genetic networks, to genes implicated in the control of menarche. Conclusion: No TTF1 or EAP1 germline mutations were associated with central pubertal disorders. TTF1 and EAP1 may affect puberty by changing expression in response to other members of puberty-associated gene networks, or by differentially affecting the expression of gene components of these networks. (C) 2013 S. Karger AG, Basel
bookPart Tumores da glândula adrenal(2013) ALMEIDA, Madson Q.; LATRONICO, Ana Claudia- Approach to the Patient With Hypogonadotropic Hypogonadism(2013) SILVEIRA, Leticia Ferreira Gontijo; LATRONICO, Ana ClaudiaHypogonadotropic hypogonadism (HH) or secondary hypogonadism is defined as a clinical syndrome that results from gonadal failure due to abnormal pituitary gonadotropin levels. HH may result from either absent or inadequate hypothalamic GnRH secretion or failure of pituitary gonadotropin secretion. Several congenital and acquired causes, including functional and organic forms, have been associated with this condition. One important aspect of the HH diagnosis is that it may reflect the presence of a tumor of the hypothalamic pituitary region or even a systemic disease. On the other hand, functional forms of HH, characterized by a transient defect in GnRH secretion, are relatively common in women, in response to significant weight loss, exercise, or stress leading to hypothalamic amenorrhea. HH is typically characterized by low circulating sexual steroids associated with low or inappropriately normal gonadotropin levels. The precise and early diagnosis of HH can prevent negative physical and psychological sequelae, preserve normal peak bone mass, and restore the fertility in affected patients.
bookPart Manuseio do retardo puberal(2013) GADELHA, Patricia Sampaio; COSTA, Elaine Maria Frade; LATRONICO, Ana Claudia; MENDONçA, Berenice Bilharinho de- POD-1 binding to the E-box sequence inhibits SF-1 and StAR expression in human adrenocortical tumor cells(2013) FRANCA, Monica Malheiros; FERRAZ-DE-SOUZA, Bruno; SANTOS, Mariza Gerdulo; LERARIO, Antonio Marcondes; FRAGOSO, Maria Candida Barisson Villares; LATRONICO, Ana Claudia; KUICK, Rork D.; HAMMER, Gary D.; LOTFI, Claudimara F. P.Pod-1/Tcf21 is expressed at epithelial-mesenchymal interaction sites during development of many organs. Different approaches have demonstrated that Pod-1 transcriptionally inhibits Sf-1/NR5A1 during gonadal development. Disruption of Sf-1 can lead to disorders of adrenal development, while increased dosage of SF-1 has been related to increased adrenal cell proliferation and tumorigenesis. In this study, we analyzed whether POD-1 overexpression inhibits the endogenous Sf-1 expression in human and mouse adrenocortical tumor cells. Cells were transiently transfected with luciferase reporter gene under the control of Sf-1 promoter and with an expression vector encoding Pod-1. Pod-1 construct inhibited the transcription of the Sf1/Luc reporter gene in a dose-dependent manner in mouse Y-1 adrenocortical carcinoma (ACC) cells, and inhibited endogenous SF-1 expression in the human H295R and ACC-T36 adrenocortical carcinoma cells. These results were validated by chromatin immunoprecipitation assay with POD-1-transfected H295R cells using primers specific to E-box sequence in SF-1 promoter region, indicating that POD-1 binds to the SF-1 E-box promoter. Moreover, POD-1 over-expression resulted in a decrease in expression of the SF-1 target gene, StAR (Steroidogenic Acute Regulatory Protein). Lastly, while the induced expression of POD-1 did not affect the cell viability of H295R/POD-1 or ACC-T36/POD-1 cells, the most significantly enriched KEGG pathways for genes negatively correlated to POD-1/TCF21 in 33 human ACCs were those associated with cell cycle genes.
- Central Precocious Puberty Caused by Mutations in the Imprinted Gene MKRN3(2013) ABREU, Ana Paula; DAUBER, Andrew; MACEDO, Delanie B.; NOEL, Sekoni D.; BRITO, Vinicius N.; GILL, John C.; CUKIER, Priscilla; THOMPSON, Iain R.; NAVARRO, Victor M.; GAGLIARDI, Priscila C.; RODRIGUES, Tania; KOCHI, Cristiane; LONGUI, Carlos Alberto; BECKERS, Dominique; ZEGHER, Francis de; MONTENEGRO, Luciana R.; MENDONCA, Berenice B.; CARROLL, Rona S.; HIRSCHHORN, Joel N.; LATRONICO, Ana Claudia; KAISER, Ursula B.BACKGROUND The onset of puberty is first detected as an increase in pulsatile secretion of gonadotropin-releasing hormone (GnRH). Early activation of the hypothalamic-pituitary-gonadal axis results in central precocious puberty. The timing of pubertal development is driven in part by genetic factors, but only a few, rare molecular defects associated with central precocious puberty have been identified. METHODS We performed whole-exome sequencing in 40 members of 15 families with central precocious puberty. Candidate variants were confirmed with Sanger sequencing. We also performed quantitative real-time polymerase-chain-reaction assays to determine levels of messenger RNA (mRNA) in the hypothalami of mice at different ages. RESULTS We identified four novel heterozygous mutations in MKRN3, the gene encoding makorin RING-finger protein 3, in 5 of the 15 families; both sexes were affected. The mutations included three frameshift mutations, predicted to encode truncated proteins, and one missense mutation, predicted to disrupt protein function. MKRN3 is a paternally expressed, imprinted gene located in the Prader-Willi syndrome critical region (chromosome 15q11-q13). All affected persons inherited the mutations from their fathers, a finding that indicates perfect segregation with the mode of inheritance expected for an imprinted gene. Levels of Mkrn3 mRNA were high in the arcuate nucleus of prepubertal mice, decreased immediately before puberty, and remained low after puberty. CONCLUSIONS Deficiency of MKRN3 causes central precocious puberty in humans.
- Combined use of multiplex ligation-dependent probe amplification and automatic sequencing for identification of KAL1 defects in patients with Kallmann syndrome(2013) MONTENEGRO, Luciana Ribeiro; SILVEIRA, Leticia F. G.; TUSSET, Cintia; CASTRO, Margaret de; VERSIANI, Beatriz R.; LATRONICO, Ana Claudia; MENDONCA, Berenice Bilharinho; TRARBACH, Ericka B.Objective: To investigate the role of KAL1 abnormalities in Brazilian patients with Kallmann syndrome. Design: In vitro experiments. Setting: Academic medical center. Patient(s): One hundred fifteen Brazilian patients (98 men) with Kallmann syndrome. Intervention(s): Peripheral blood leukocytes were used to obtain DNA. Main Outcome Measure(s): Direct sequencing and multiplex ligation-dependent probe amplification were used to identify KAL1 abnormalities. Result(s): We identified four KAL1 mutations (p.Met1?, p.Ala33Glyfs, p.Arg257*, and p.Trp462*) and two multiple exon deletions (exons 1-2 and 3-14) in six new male patients. Overall, 17 KAL1 defects (14.8%) were identified in the entire cohort of patients with Kallmann syndrome, including previously studied cases. KAL1-mutated patients presented with a more severe reproductive and nonreproductive phenotype (synkinesia, renal malformations, cryptorchidism, and anatomic olfactory abnormalities) in comparison with patients without KAL1 mutations. Intragenic deletions were one of the most often encountered defects (29.4%). These deletions can be missed by polymerase chain reaction (PCR) due to Yq11.2 KAL1 pseudogene (KALP) spurious amplification. Conclusion(s): These results indicate that intragenic multiexon deletions are one of the most frequent KAL1 abnormalities, which can be more accurately detected by multiplex ligation-dependent probe amplification. In addition, KAL1 sequencing results should be interpreted with caution, and stringency conditions of the PCR reaction should be adjusted to avoid pseudogene amplification. (C) 2013 by American Society for Reproductive Medicine.
- Gonadotropin Resistance(2013) LATRONICO, Ana Claudia; ARNHOLD, Ivo Jorge PradoPituitary gonadotropins are essential for normal reproductive function. LH and FSH exert their effects by acting on G protein-coupled receptors. Pituitary LH and placental hCG share the same receptor (LHCGR). Homozygous or compound heterozygous inactivating mutations of LHCGR are associated with a phenotypic spectrum from female or ambiguous external genitalia due to Leydig cell hypoplasia to micropenis, hypergonadotropic hypogonadism and delayed puberty in genetic males. Testes size is slightly reduced, and testosterone levels are low in affected males. Interestingly, the clinical phenotypes are closely correlated with the severity of the mutation. In females, the phenotype is also variable and can range from primary amenorrhea to oligoamenorrhea, associated with constant infertility. Estradiol and progesterone levels remain in the early to mid-follicular phase, whereas the ovaries are normal or enlarged with cysts. In both sexes, LH levels are increased, whereas FSH is usually normal. Inactivating mutations of FSH receptor are associated with partial to complete premature ovarian failure in women and variable impairment of spermatogenesis and small testes in men. Mutations of the human gonadotropin receptors provide natural models for elucidating the differential effects of LH and FSH on the gonads.