RESUMO
Calcium channels control the inflow of calcium ions into cells and are involved in diverse cellular functions. The CACNA1C gene polymorphism rs1006737 A allele has been strongly associated with increased risk for bipolar disorder (BD) and with modulation of brain morphology. The medial prefrontal cortex (mPFC) has been widely associated with mood regulation in BD, but the role of this CACNA1C polymorphism in mPFC morphology and brain aging has yet to be elucidated. One hundred seventeen euthymic BD type I subjects were genotyped for CACNA1C rs1006737 and underwent 3 T three-dimensional structural magnetic resonance imaging scans to determine cortical thickness of mPFC components (superior frontal cortex (sFC), medial orbitofrontal cortex (mOFC), caudal anterior cingulate cortex (cACC) and rostral anterior cingulate cortex (rACC)). Carriers of the CACNA1C allele A exhibited greater left mOFC thickness compared to non-carriers. Moreover, CACNA1C A carriers showed age-related cortical thinning of the left cACC, whereas among A non-carriers there was not an effect of age on left cACC cortical thinning. In the sFC, mOFC and rACC (left or right), a negative correlation was observed between age and cortical thickness, regardless of CACNA1C rs1006737 A status. Further studies investigating the direct link between cortical thickness, calcium channel function, apoptosis mechanism and their underlying relationship with aging-associated cognitive decline in BD are warranted.
Assuntos
Alelos , Transtorno Bipolar/genética , Transtorno Bipolar/patologia , Canais de Cálcio Tipo L/genética , Predisposição Genética para Doença/genética , Córtex Pré-Frontal/patologia , Adolescente , Adulto , Fatores Etários , Transtorno Bipolar/diagnóstico por imagem , Dominância Cerebral/genética , Dominância Cerebral/fisiologia , Feminino , Triagem de Portadores Genéticos , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Polimorfismo Genético/genética , Córtex Pré-Frontal/diagnóstico por imagem , Estatística como Assunto , Adulto JovemRESUMO
BACKGROUND: Pituitary tumors account for approximately 10-15% of intracranial neoplasms. AIM: Using the cDNA microarray method, we have previously compared expression under two distinct conditions: a pool of 4 clinically non-functioning pituitary adenomas (NFPA) and a spinal cord metastasis of a non-functioning pituitary carcinoma, in order to gain biological insights into genomic changes of pituitary neoplasias. In the present study, we further investigated the mRNA expression of 3 selected genes previously described as being involved in other neoplasias based on a series of 60 pituitary adenomas: CRABP1 (cellular retinoic acid binding protein 1), GRP (gastrin-releasing peptide), and RERG (Ras-related, estrogen- regulated, growth inhibitor). MATERIAL AND METHODS: The expression of CRABP1, GRP, and RERG was determined by quantitative RT-PCR. RESULTS: A significantly higher content of CRABP1 mRNA was observed in NFPA compared to functioning adenomas, and PRL-secreting adenomas showed a lower expression of this gene compared to normal pituitary. A lower expression of GRP mRNA was detected in NFPA compared to normal pituitary and also to functioning adenomas. RERG mRNA was overexpressed in NFPA in comparison to functioning adenomas and to normal pituitary. Among the functioning adenomas, only the ACTH-secreting adenomas presented a higher expression of RERG mRNA compared to normal pituitary. CONCLUSIONS: The findings of differential expression of CRABP1 in prolactinomas and of RERG in NFPA compared to normal pituitary suggests that retinoic acid and estrogen receptor, respectively, could be involved in the tumorigenesis of these adenomas subtypes. Additional studies are required to further confirm this hypothesis.
Assuntos
Adenoma Hipofisário Secretor de ACT/metabolismo , Adenoma/metabolismo , GTP Fosfo-Hidrolases , Peptídeo Liberador de Gastrina , Neoplasias Hipofisárias/metabolismo , RNA Mensageiro/metabolismo , Receptores do Ácido Retinoico , Adenoma Hipofisário Secretor de ACT/genética , Adenoma/genética , Adolescente , Adulto , Idoso , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Peptídeo Liberador de Gastrina/genética , Peptídeo Liberador de Gastrina/metabolismo , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Hipófise/metabolismo , Neoplasias Hipofisárias/genética , Prolactina/metabolismo , RNA Mensageiro/genética , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/metabolismo , Adulto JovemRESUMO
The neurotensin (NT) produced in the hypothalamus and in pituitary gonadotrophs and thyrotrophs participates in neuroendocrine regulation. Recently, the involvement of this peptide in normal and neoplastic cell proliferation has been postulated. In the present study, we evaluated the expression of NT and its receptors (NTR1, 2 and 3) in a series of 50 pituitary adenomas [11 growth hormone (GH)-, eight prolactin (PRL)-, four adrenocorticotrophic hormone (ACTH)- and 27 nonfunctioning adenomas]. NT mRNA expression was significantly higher in functioning compared to nonfunctioning adenomas and with normal pituitary. Nonfunctioning pituitary adenomas showed lower expression of NT mRNA than normal pituitary. In the immunohistochemical study of functioning adenomas, NT was colocalised with GH, PRL and ACTH secreting cells. In nonfunctioning adenomas, the NT immunoreactivity intensity was variable among the samples. NTR3 mRNA expression was observed in all examined samples and was higher in the adenomas, both functioning and nonfunctioning, compared to normal pituitary. By contrast, NTR1 and NTR2 mRNA were not detected in either pituitary adenomas or normal tissue. The higher expression of NTR3, as well as the expression of NT by tumoural corticotrophs, lactotrophs and somatotrophs, which are cells types that do not express this peptide in the normal pituitary, suggests that NT autocrine and/or paracrine stimulation mediated by NTR3 may be a mechanism associated with the tumourigenesis of functioning adenomas.
