RESUMO
Due to the current limited knowledge about the role of filamin A (FLNA) in pituitary tumour progression, we aimed to analyse FLNA expression levels and its impact on aggressive markers of pituitary neuroendocrine tumours (PitNETs), using an integrative approach of in vivo and in vitro models and human samples. An increase in the expression levels of FLNA was observed in the advanced tumoural stages of the hyperplastic adenomatous pituitary model, concomitant with a decrease in cell proliferation and with a modification in the subcellular localisation of this protein. Similarly, overexpression of FLNA in the somatolactotropic GH3 cell line induced a decrease in the cell proliferation, promoted a migratory phenotype, increased invasion activity, and decreased the prolactin secretion. Cyclin D1 (CCND1) and cyclin-dependent kinase 4 (CDK4) expression increased in both models in correlation with the increase observed in FLNA levels. When human tissues were analysed a significant increase of FLNA was observed in PitNETs compared to normal pituitary gland, with heterogeneous intracellular localisation. Higher levels of FLNA expression were observed in tumours with invasive characteristics. These results underline the crucial roles of FLNA as a modulator of pathological markers and as a potential prognostic marker in pituitary tumours.
Assuntos
Adenoma , Tumores Neuroendócrinos , Neoplasias Hipofisárias , Humanos , Neoplasias Hipofisárias/metabolismo , Filaminas/genética , Filaminas/metabolismo , Hipófise/metabolismoRESUMO
Toxicological studies have revealed that DEHP exposure during pregnancy may induce developmental disorders, especially in male offspring, leading to morphological and functional alterations in the reproductive system by mechanisms that should be investigated. Thus, the aim of this work was to analyze the testicular toxicity induced by an environmentally relevant DEHP dose during development and its impact on FLNA, a protein that participates in the blood-testis barrier assembly. We used male Wistar rats exposed to DEHP during pregnancy and lactation. The results showed that DEHP exposure during development and lactation increased body weight, decreased gonadal weight and shortened anogenital distance. This phthalate induced morphological changes in the testis, suggestive of hypospermatogenesis. DEHP exposure decreased the number of FLNA positive cells and the expression of FLNA and claudin-1 in prepubertal testes. Furthermore, DEHP inhibited FLNA and claudin-1 protein expression in adult male rats. These results indicated that exposure to DEHP during gestation and lactation perturbed testis development and suggested that FLNA is a target protein of DEHP, possibly contributing to the phthalate-induced damage on BTB.
Assuntos
Dietilexilftalato , Efeitos Tardios da Exposição Pré-Natal , Gravidez , Feminino , Ratos , Masculino , Animais , Humanos , Testículo/metabolismo , Dietilexilftalato/toxicidade , Dietilexilftalato/metabolismo , Filaminas/metabolismo , Claudina-1/metabolismo , Ratos Wistar , Lactação , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/metabolismoRESUMO
PURPOSE: Filamin A (FLNA) expression is related to dopamine receptor type 2 (DRD2) expression in prolactinomas. Nevertheless, in corticotrophinomas, there are few studies about DRD2 expression and no data on FLNA. Therefore, we evaluated FLNA and DRD2 expression in corticotrophinomas and their association with tumor characteristics. METHODS: DRD2 and FLNA expression by immunohistochemistry, using H-score, based on the percentage of positive cells in a continuous scale of 0-300, were evaluated in 23 corticotrophinomas samples from patients submitted to neurosurgery. In six patients, treatment with cabergoline was indicated after non curative surgery. RESULTS: Twenty-two patients were female and one male. Regarding tumor size, 10 were micro and 12 were macroadenomas. DRD2 expression was found in 89% of cases and did not correlate with FLNA expression. Moreover, the response to cabergoline, observed in 33% of the cases, did not correlate with DRD2 nor FLNA expression. FLNA expression was not associated with clinical and tumor characteristics, except for sphenoid sinus invasion. CONCLUSIONS: In our cohort of corticotrophinomas, DRD2 expression was not associated with FLNA expression nor to the response to CAB. Nonetheless, FLNA expression could be related to tumor invasiveness.
Assuntos
Adenoma Hipofisário Secretor de ACT/metabolismo , Filaminas/metabolismo , Receptores de Dopamina D2/metabolismo , Adolescente , Adulto , Idoso , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
Filamin-A (FLNA) plays a crucial role in somatostatin receptor (sst) subtype-2 signaling in somatotropinomas. Our objective was to investigate the in vivo association between FLNA and sst2 expression, sst5 expression, dopamine receptor subtype-2 (D2) expression, somatostatin receptor ligand (SRL) responsiveness and tumor invasiveness in somatotropinomas. Quantitative real-time PCR was used to evaluate the absolute mRNA copy numbers of FLNA/sst2/sst5/D2 in 96 somatotropinomas. FLNA, sst2 and sst5 protein expression levels were also evaluated using immunohistochemistry. The Knosp-Steiner criteria were used to evaluate tumor invasiveness. Median FLNA, sst2, sst5 and D2 copy numbers were 4,244, 731, 156 and 3,989, respectively. Thirty-one of the 35 available tumors (89%) were immune positive for FLNA in the cytoplasm and membrane but not in the nucleus. FLNA and sst5 expression were positively correlated at the mRNA and protein levels (p < 0.001 and p = 0.033, respectively). FLNA was positively correlated with sst2 mRNA in patients who were responsive to SRL (p = 0.014, R = 0.659). No association was found between FLNA and tumor invasiveness. Our findings show that in somatotropinomas FLNA expression positively correlated with in vivo sst5 and D2 expression. Notably, FLNA was only correlated with sst2 in patients who were controlled with SRL. FLNA was not associated with tumor invasiveness.
Assuntos
Acromegalia/genética , Adenoma/tratamento farmacológico , Antineoplásicos/administração & dosagem , Filaminas/genética , Adenoma Hipofisário Secretor de Hormônio do Crescimento/tratamento farmacológico , Receptores de Dopamina D2/genética , Receptores de Somatostatina/genética , Acromegalia/etiologia , Acromegalia/metabolismo , Adenoma/complicações , Adenoma/genética , Adenoma/metabolismo , Adolescente , Adulto , Idoso , Antineoplásicos/uso terapêutico , Membrana Celular/genética , Membrana Celular/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Citoplasma/genética , Citoplasma/metabolismo , Feminino , Filaminas/metabolismo , Adenoma Hipofisário Secretor de Hormônio do Crescimento/complicações , Adenoma Hipofisário Secretor de Hormônio do Crescimento/genética , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Octreotida/administração & dosagem , Octreotida/uso terapêutico , Peptídeos Cíclicos/administração & dosagem , Peptídeos Cíclicos/uso terapêutico , Receptores de Dopamina D2/metabolismo , Receptores de Somatostatina/metabolismo , Somatostatina/administração & dosagem , Somatostatina/análogos & derivados , Somatostatina/uso terapêutico , Carga Tumoral , Adulto JovemRESUMO
During musculoskeletal system development, mechanical tension is generated between muscles and tendon-cells. This tension is required for muscle differentiation and is counterbalanced by tendon-cells avoiding tissue deformation. Both, Jbug/Filamin, an actin-meshwork organizing protein, and non-muscle Myosin-II (Myo-II) are required to maintain the shape and cell orientation of the Drosophila notum epithelium during flight muscle attachment to tendon cells. Here we show that halving the genetic dose of Rho kinase (Drok), the main activator of Myosin-II, enhances the epithelial deformation and bristle orientation defects associated with jbug/Filamin knockdown. Drok and activated Myo-II localize at the apical cell junctions, tendon processes and are associated to the myotendinous junction. Further, we found that Jbug/Filamin co-distribute at tendon cells with activated Myo-II. Finally, we found that Jbug/Filamin and Myo-II are in the same molecular complex and that the actin-binding domain of Jbug/Filamin is necessary for this interaction. These data together suggest that Jbug/Filamin and Myo-II proteins may act together in tendon cells to balance the tension generated during development of muscles-tendon interaction, maintaining the shape and polarity of the Drosophila notum epithelium.
Assuntos
Polaridade Celular/fisiologia , Epitélio/metabolismo , Filaminas/metabolismo , Desenvolvimento Musculoesquelético/fisiologia , Miosina Tipo II/metabolismo , Tendões/metabolismo , Actinas/metabolismo , Animais , Diferenciação Celular/fisiologia , Células Cultivadas , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Drosophila melanogaster/fisiologia , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Tendões/fisiologia , Quinases Associadas a rho/metabolismoRESUMO
Maintenance of endoplasmic reticulum (ER) proteostasis is controlled by a signalling network known as the unfolded protein response (UPR). Here, we identified filamin A as a major binding partner of the ER stress transducer IRE1α. Filamin A is an actin crosslinking factor involved in cytoskeleton remodelling. We show that IRE1α controls actin cytoskeleton dynamics and affects cell migration upstream of filamin A. The regulation of cytoskeleton dynamics by IRE1α is independent of its canonical role as a UPR mediator, serving instead as a scaffold that recruits and regulates filamin A. Targeting IRE1α expression in mice affected normal brain development, generating a phenotype resembling periventricular heterotopia, a disease linked to the loss of function of filamin A. IRE1α also modulated cell movement and cytoskeleton dynamics in fly and zebrafish models. This study unveils an unanticipated biological function of IRE1α in cell migration, whereby filamin A operates as an interphase between the UPR and the actin cytoskeleton.
Assuntos
Citoesqueleto de Actina/metabolismo , Movimento Celular , Endorribonucleases/metabolismo , Fibroblastos/metabolismo , Filaminas/metabolismo , Neurônios/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Endorribonucleases/deficiência , Endorribonucleases/genética , Evolução Molecular , Feminino , Filaminas/genética , Células HEK293 , Humanos , Cinética , Masculino , Camundongos , Camundongos Knockout , Neurônios/patologia , Heterotopia Nodular Periventricular/genética , Heterotopia Nodular Periventricular/metabolismo , Heterotopia Nodular Periventricular/patologia , Fosforilação , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais , Resposta a Proteínas não Dobradas , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
The immune system in marine invertebrates is mediated through cellular and humoral components, which act together to address the action of potential pathogenic microorganisms. In bivalve mollusks biomolecules implicated in oxidative stress and recognition of pathogens have been involved in the innate immune response. To better understand the molecular basis of the immune response of surf clam Mesodesma donacium, qPCR approaches were used to identify genes related to its immune response against Vibrio anguillarum infection. Genes related to oxidative stress response and recognition of pathogens like superoxide dismutase (MdSOD), catalase (MdCAT), ferritin (MdFER) and filamin (MdFLMN) were identified from 454-pyrosequencing cDNA library of M. donacium and were evaluated in mantle, adductor muscle and gills. The results for transcripts expression indicated that MdSOD, MdFLMN and MdFER were primarily expressed in the muscle, while MdCAT was more expressed in gills. Challenge experiments with the pathogen V. anguillarum had showed that levels of transcript expression for MdSOD, MdCAT, MdFER, and MdFLMN were positively regulated by pathogen, following a time-dependent expression pattern with significant statistical differences between control and challenge group responses (p<0.05). These results suggest that superoxide dismutase, catalase, ferritin and filamin, could be contributing to the innate immune response of M. donacium against the pathogen V. anguillarum.
Assuntos
Bivalves/genética , Bivalves/imunologia , Imunidade Inata/genética , Vibrio/imunologia , Animais , Sequência de Bases , Bivalves/microbiologia , Catalase/genética , Catalase/metabolismo , DNA Complementar/genética , Ferritinas/genética , Ferritinas/metabolismo , Filaminas/genética , Filaminas/metabolismo , Dados de Sequência Molecular , Músculos/metabolismo , Estresse Oxidativo/genética , Análise de Sequência de DNA , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismoRESUMO
The cytoskeleton mediates various cellular processes such as differentiation and fusion, including in the filopodia and podosomes. However, apart from cell migration and formation of the sealing zone, little is known regarding the changes and related regulatory mechanisms of the cytoskeleton and additional roles of the filopodia and podosomes during the differentiation and fusion of osteoclasts. The cytomorphology and cytoskeleton of osteoclasts in the differentiation process were evaluated using tartrate-resistant acid phosphatase staining and immunofluorescence staining. Moreover, the expression levels of Rho GTPases and enzymes related to osteoclast differentiation and bone resorption were detected by quantitative reverse transcription-polymerase chain reaction. We detected 3 types of filopodia in osteoclast precursors and only 1 type of filopodia in undifferentiated cells. Mature osteoclasts were completely devoid of filopodia. Interestingly, cell fusion was highly specific, and the fusion initially occurred to the filopodia. Confocal images revealed that F-actin and microtubules significantly differed among fused cells. These results suggest that filopodia and podosomes not only play important roles in cell migration and the formation of sealing zones but also in the pre-fusion selectivity of 2 cells and the movement direction of the cell nucleus and cytoplasm during the fusion process. In addition, cdc42v1, RhoU, and RhoF regulate the formation of 3 types of filopodia during various stages of differentiation, while Rac1, Rac2, and filament A may be associated with cell selectivity during the fusion process.