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1.
Ultrasound Obstet Gynecol ; 62(6): 875-881, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37266920

RESUMO

OBJECTIVE: To assess the role of the choroid plexus (CP) of the fourth ventricle (4V) in fetuses with an open 4V and a normal cerebellar vermis. METHODS: Two groups of patients were recruited in two fetal medicine referral centers. The prospectively collected control group included singleton pregnancies with a normal sonographic examination after first-trimester combined screening for chromosomal abnormalities and normal outcome, recruited in the period between 2019 and 2022. The study group was selected retrospectively by searching our databases to identify all cases with an isolated open 4V and normal anatomy and size of the cerebellar vermis. The inclusion criteria of the study group were: (1) gestational age between 20 and 22 weeks; (2) a brainstem-vermis angle ≥ 18° in the midsagittal plane with an otherwise normal cerebellum and vermis; (3) 4V-CP visible and seen separately from the vermis; (4) absence of other intra- and extracranial anomalies; and (5) available prenatal and/or postnatal magnetic resonance imaging (MRI) data. RESULTS: In 169 cases of the control group, the 4V-CP was seen separately from the cerebellar vermis and was noticed to progressively fill the space caudal to the 4V, between the vermis and brainstem. From 12 to 22 weeks, the surface areas of the vermis and medial portion of the 4V-CP increased progressively with advancing gestation (P < 0.0001). Intra- and interobserver correlation analysis showed good reproducibility for the measurements. Among the cases with an open 4V and a normal vermis, it was retrospectively feasible to visualize the 4V-CP separately from the inferior part of the vermis in 41 fetuses. In five of these cases, the open 4V was due to a small CP. In all 41 fetuses, the diagnosis on MRI was isolated upward rotation of the cerebellar vermis, and no additional anomaly was found. CONCLUSIONS: Closure of the 4V is dependent on the 4V-CP and not only the cerebellar vermis. In fact, a small CP may represent another cause of an open 4V. Therefore, separate visualization of the 4V-CP and cerebellar vermis is crucial to improve discrimination between the different causes of an open 4V at the anomaly scan and its clinical implications. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Plexo Corióideo , Quarto Ventrículo , Feminino , Gravidez , Humanos , Lactente , Quarto Ventrículo/diagnóstico por imagem , Plexo Corióideo/diagnóstico por imagem , Estudos Retrospectivos , Reprodutibilidade dos Testes , Ultrassonografia Pré-Natal/métodos , Diagnóstico Pré-Natal , Idade Gestacional , Imageamento por Ressonância Magnética/métodos
3.
Ultrasound Obstet Gynecol ; 59(1): 49-54, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34125985

RESUMO

OBJECTIVE: To evaluate whether in fetuses with open spina bifida (OSB) the tentorium can be seen to be displaced downwards and vertically oriented by the time of the 11-13-week scan and whether this is reflected in an alteration of the brainstem-tentorium (BST) angle. METHODS: The study population was recruited between 2015 and 2020 from three fetal medicine referral centers and comprised a control group and a study group of pregnancies with OSB. The control group was recruited prospectively and included singleton pregnancies with a normal sonographic examination after first-trimester combined screening for chromosomal abnormalities and normal outcome. The study group was selected retrospectively and included all cases with OSB between 2015 and 2020. All cases underwent detailed ultrasound assessment at 11 + 0 to 13 + 6 weeks' gestation. The position of the torcular Herophili (TH) was identified in the midsagittal view of the fetal brain with the use of color Doppler and was considered as a proxy for the insertion of the tentorium on the fetal skull. The BST angle was calculated in the same view and was compared between the two groups. RESULTS: Sixty normal fetuses were included in the control group and 22 fetuses with OSB in the study group. In both groups, the BST angle was found to be independent of gestational age or crown-rump length (P = 0.8815, R2 = 0.0003861 in the controls, and P = 0.2665, R2 = 0.00978 in the OSB group). The mean BST angle was 48.7 ± 7.8° in controls and 88.1 ± 1.18°, i.e. close to 90°, in fetuses with OSB. Comparison of BST-angle measurements between the control group and cases with OSB showed a statistically significant difference (P = 0.0153). In all fetuses with OSB, the downward displacement of the TH and tentorium was clearly visible at the 11-13-week scan. CONCLUSIONS: In fetuses with OSB, the BST angle is significantly larger than in normal controls, with the tentorium being almost perpendicular to the brainstem. This sign confirms the inferior displacement of the tentorium cerebelli with respect to its normal insertion on the occipital clivus as early as the first trimester of pregnancy and is useful in the diagnosis of Chiari-II malformation at this early stage. In fetuses with OSB, the low position of the tentorium and TH is clearly visible, even subjectively, at the 11-13-week scan. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Feto/diagnóstico por imagem , Espinha Bífida Cística/diagnóstico por imagem , Disrafismo Espinal/diagnóstico por imagem , Ultrassonografia Pré-Natal , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/embriologia , Estudos de Casos e Controles , Fossa Craniana Posterior/diagnóstico por imagem , Fossa Craniana Posterior/embriologia , Cavidades Cranianas/diagnóstico por imagem , Cavidades Cranianas/embriologia , Dura-Máter/diagnóstico por imagem , Dura-Máter/embriologia , Feminino , Feto/embriologia , Idade Gestacional , Humanos , Gravidez , Primeiro Trimestre da Gravidez , Estudos Prospectivos , Estudos Retrospectivos , Espinha Bífida Cística/embriologia , Disrafismo Espinal/embriologia
4.
Ultrasound Obstet Gynecol ; 58(4): 568-575, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33847428

RESUMO

OBJECTIVE: To describe the sonographic appearance and position of the choroid plexus of the fourth ventricle (4V-CP) between 12 and 21 weeks' gestation in normal fetuses and in fetuses with Dandy-Walker malformation (DWM) or Blake's pouch cyst (BPC). METHODS: The study population comprised 90 prospectively recruited normal singleton pregnancies and 41 pregnancies identified retrospectively from our institutional database that had a suspected posterior fossa anomaly at 12-13 weeks' gestation based on the ultrasound finding of abnormal hindbrain spaces. In all cases the final diagnosis was confirmed by prenatal and/or postnatal magnetic resonance imaging or postmortem examination. All pregnancies underwent a detailed ultrasound assessment, including a dedicated examination of the posterior fossa, at 12-13 weeks, 15-16 weeks and 20-21 weeks of gestation. Two-dimensional ultrasound images of the midsagittal and coronal views of the brain through the posterior fontanelle and three-dimensional volume datasets were obtained. Multiplanar orthogonal image correlation with volume contrast imaging was used as the reference visualization mode. Two independent operators, blinded to the fetal outcome, were asked to classify the 4V-CP as visible or not visible in both normal and abnormal cases, and to assess if the 4V-CP was positioned inside or outside the cyst in fetuses with DWM and BPC. RESULTS: Of the 41 fetuses with apparently isolated cystic posterior fossa anomaly in the first trimester, eight were diagnosed with DWM, 29 were diagnosed with BPC and four were found to be normal in the second trimester. The position of the 4V-CP differed between DWM, BPC and normal cases in the first- and second-trimester ultrasound examinations. In particular, in normal fetuses, no cyst was present and, in the midsagittal and coronal planes of the posterior fossa, the 4V-CP appeared as an echogenic oval-shaped structure located inside the 4V apparently attached to the cerebellar vermis. In fetuses with DWM, the 4V-CP was not visible in the midsagittal view because it was displaced inferolaterally by the cyst. In contrast, in the coronal view of the posterior brain, the 4V-CP was visualized in all cases with DWM at 12-13 weeks, with a moderate decrease in the visualization rate at 15-16 weeks (87.5%) and at 20-21 weeks (75%). In the coronal view, the 4V-CP was classified as being outside the cyst in all DWM cases at 12-13 weeks and in 87.5% and 75% of cases at 15-16 and 20-21 weeks, respectively. In fetuses with BPC, the 4V-CP was visualized in all cases in both the midsagittal and coronal views at 12-13 weeks and in 100% and 96.6% of cases, respectively, at 15-16 weeks. In the coronal view, the 4V-CP was classified as being inside the cyst in 28 (96.6%), 27 (93.1%) and 25 (86.2%) cases at 12-13, 15-16 and 20-21 weeks, respectively. The medial segment of the 4V-CP was visualized near the inferior part of the vermis. CONCLUSIONS: Our study shows that longitudinal ultrasound assessment of the 4V-CP and its temporal changes from 12 to 21 weeks is feasible. The 4V-CP is located inside the cyst, just below the vermis, in BPC and outside the cyst, inferolaterally displaced and distant from the vermian margin, in DWM, consistent with the pathogenesis of the two conditions. The position of the 4V-CP is a useful sonographic marker that can help differentiate between DWM and BPC as early as in the first trimester of pregnancy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Cistos do Sistema Nervoso Central/diagnóstico por imagem , Plexo Corióideo/embriologia , Síndrome de Dandy-Walker/diagnóstico por imagem , Quarto Ventrículo/embriologia , Ultrassonografia Pré-Natal/métodos , Cistos do Sistema Nervoso Central/embriologia , Plexo Corióideo/diagnóstico por imagem , Plexo Corióideo/patologia , Fossa Craniana Posterior/diagnóstico por imagem , Fossa Craniana Posterior/embriologia , Fossa Craniana Posterior/patologia , Síndrome de Dandy-Walker/embriologia , Bases de Dados Factuais , Diagnóstico Diferencial , Diagnóstico Precoce , Estudos de Viabilidade , Feminino , Feto/diagnóstico por imagem , Feto/embriologia , Quarto Ventrículo/diagnóstico por imagem , Quarto Ventrículo/patologia , Humanos , Gravidez , Primeiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Estudos Retrospectivos
5.
Ultrasound Obstet Gynecol ; 51(2): 214-218, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28078737

RESUMO

OBJECTIVES: To introduce a new sonographic marker of intrathoracic liver herniation in fetuses with left-sided congenital diaphragmatic hernia (CDH). METHODS: In a consecutive series of fetuses with isolated CDH, an ultrasound volume of the fetal abdomen was acquired. On this volume, offline calculation of the angle formed by the midline of the abdomen (joining the center of the vertebral body to the abdominal insertion of the umbilical cord) and a second line joining the center of the vertebral body to the intra-abdominal convexity of the umbilical vein was carried out to give the umbilical vein deviation angle (UVDA). The UVDA was measured in a group of normal fetuses selected as controls. At follow-up, the presence of liver herniation was investigated in all cases of CDH. UVDA values were compared between the CDH group and controls, and between CDH 'liver-up' vs 'liver-down' cases. A receiver-operating characteristics (ROC) curve was constructed to identify a cut-off value of the UVDA with the highest accuracy in predicting liver herniation in the CDH group. RESULTS: Between 2009 and 2015, 22 cases of left-sided CDH were included in the study group, of which nine cases had liver herniation. Eighty-eight normal fetuses were recruited as controls. The UVDA was significantly higher in the cases vs controls (15.25 ± 7.91° vs 7.68 ± 1.55°; P < 0.0001). Moreover, the UVDA was significantly increased in CDH fetuses with liver-up vs liver-down (21.77 ± 8.79° vs 10.75 ± 2.10°; P < 0.0001). On ROC curve analysis the UVDA showed good prediction of liver herniation (area under the ROC curve, 0.94; P < 0.0001) with the best cut-off of 15.2°, yielding a sensitivity of 89% and a specificity of 100% (P < 0.0001). CONCLUSIONS: In fetuses with CDH, umbilical vein bowing may be quantified by measuring the UVDA using three-dimensional ultrasound. This sonographic marker seems to be an accurate predictor of liver herniation in left-sided CDH. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Ecocardiografia Tridimensional , Doenças Fetais/diagnóstico por imagem , Hérnias Diafragmáticas Congênitas/diagnóstico por imagem , Hepatopatias/diagnóstico por imagem , Fígado/diagnóstico por imagem , Ultrassonografia Pré-Natal , Adulto , Feminino , Doenças Fetais/patologia , Testes Genéticos , Idade Gestacional , Hérnias Diafragmáticas Congênitas/embriologia , Hérnias Diafragmáticas Congênitas/patologia , Humanos , Itália , Fígado/embriologia , Hepatopatias/embriologia , Hepatopatias/patologia , Gravidez , Estudos Prospectivos , Curva ROC , Veias Umbilicais/anormalidades , Veias Umbilicais/diagnóstico por imagem
6.
Leukemia ; 32(2): 438-449, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28745329

RESUMO

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by hyperplastic megakaryopoiesis and myelofibrosis. We recently described the upregulation of MAF (v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog) in PMF CD34+ hematopoietic progenitor cells (HPCs) compared to healthy donor. Here we demonstrated that MAF is also upregulated in PMF compared with the essential thrombocytemia (ET) and polycytemia vera (PV) HPCs. MAF overexpression and knockdown experiments shed some light into the role of MAF in PMF pathogenesis, by demonstrating that MAF favors the megakaryocyte and monocyte/macrophage commitment of HPCs and leads to the increased expression of proinflammatory and profibrotic mediators. Among them, we focused our further studies on SPP1 and LGALS3. We assessed SPP1 and LGALS3 protein levels in 115 PMF, 47 ET and 24 PV patients plasma samples and we found that SPP1 plasma levels are significantly higher in PMF compared with ET and PV patients. Furthermore, in vitro assays demonstrated that SPP1 promotes fibroblasts and mesenchymal stromal cells proliferation and collagen production. Strikingly, clinical correlation analyses uncovered that higher SPP1 plasma levels in PMF patients correlate with a more severe fibrosis degree and a shorter overall survival. Collectively our data unveil that MAF overexpression contributes to PMF pathogenesis by driving the deranged production of the profibrotic mediator SPP1.


Assuntos
Medula Óssea/metabolismo , Medula Óssea/patologia , Fibrose/metabolismo , Fibrose/patologia , Osteopontina/metabolismo , Proteínas Proto-Oncogênicas c-maf/metabolismo , Antígenos CD34/metabolismo , Proliferação de Células/fisiologia , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/patologia , Humanos , Megacariócitos/metabolismo , Megacariócitos/patologia , Transtornos Mieloproliferativos/metabolismo , Transtornos Mieloproliferativos/patologia , Policitemia Vera/metabolismo , Policitemia Vera/patologia , Mielofibrose Primária/metabolismo , Mielofibrose Primária/patologia , Trombocitemia Essencial/metabolismo , Trombocitemia Essencial/patologia
7.
Blood Cancer J ; 6(6): e439, 2016 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-27341078

RESUMO

microRNAs (miRNAs) are relevant in the pathogenesis of primary myelofibrosis (PMF) but our understanding is limited to specific target genes and the overall systemic scenario islacking. By both knowledge-based and ab initio approaches for comparative analysis of CD34+ cells of PMF patients and healthy controls, we identified the deregulated pathways involving miRNAs and genes and new transcriptional and post-transcriptional regulatory circuits in PMF cells. These converge in a unique and integrated cellular process, in which the role of specific miRNAs is to wire, co-regulate and allow a fine crosstalk between the involved processes. The PMF pathway includes Akt signaling, linked to Rho GTPases, CDC42, PLD2, PTEN crosstalk with the hypoxia response and Calcium-linked cellular processes connected to cyclic AMP signaling. Nested on the depicted transcriptional scenario, predicted circuits are reported, opening new hypotheses. Links between miRNAs (miR-106a-5p, miR-20b-5p, miR-20a-5p, miR-17-5p, miR-19b-3p and let-7d-5p) and key transcription factors (MYCN, ATF, CEBPA, REL, IRF and FOXJ2) and their common target genes tantalizingly suggest new path to approach the disease. The study provides a global overview of transcriptional and post-transcriptional deregulations in PMF, and, unifying consolidated and predicted data, could be helpful to identify new combinatorial therapeutic strategy. Interactive PMF network model: http://compgen.bio.unipd.it/pmf-net/.


Assuntos
MicroRNAs/genética , Proteínas de Neoplasias/genética , Mielofibrose Primária/genética , Processamento Pós-Transcricional do RNA , Idoso , Idoso de 80 Anos ou mais , Antígenos CD34/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Mielofibrose Primária/patologia , Transdução de Sinais , Transcrição Gênica
8.
Ultrasound Obstet Gynecol ; 47(6): 720-5, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25914043

RESUMO

OBJECTIVE: To describe the sonographic appearance of fetal posterior fossa anatomy at 11-14 weeks of pregnancy and to assess the outcome of fetuses with increased intracranial translucency (IT) and/or brainstem-to-occipital bone (BSOB) diameter. METHODS: Reference ranges for brainstem (BS), IT and cisterna magna (CM) measurements, BSOB diameter and the BS : BSOB ratio were obtained from the first-trimester ultrasound examination of 233 fetuses with normal postnatal outcome (control group). The intraobserver and interobserver variability of measurements were investigated using 73 stored ultrasound images. In addition, a study group of 17 fetuses with increased IT and/or BSOB diameter was selected to assess outcome. RESULTS: No significant intraobserver or interobserver variability was found for any measurement in the control group. In the study group, IT was increased in all cases and BSOB diameter was above the 95(th) centile of the calculated normal range in all but two (88%) cases. In 13/17 study cases, only two of the three posterior brain spaces were recognized on ultrasound. These 13 fetuses had a larger BSOB diameter than did the four cases that showed all three posterior brain spaces, and had severe associated anomalies including Dandy-Walker malformation (DWM) and/or chromosomal anomalies. CONCLUSIONS: Visualization of the fetal posterior fossa anatomy at 11-14 weeks' gestation is feasible. Increased fluid in the posterior brain at 11-14 weeks, particularly in the case of non-visibility of the septation that divides the future fourth ventricle from the CM, is an important risk factor for cystic posterior fossa malformations, in particular DWM, and/or chromosomal aberrations. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.


Assuntos
Transtornos Cromossômicos/diagnóstico por imagem , Fossa Craniana Posterior/diagnóstico por imagem , Síndrome de Dandy-Walker/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Estudos de Casos e Controles , Aberrações Cromossômicas , Fossa Craniana Posterior/anormalidades , Feminino , Humanos , Variações Dependentes do Observador , Gravidez , Primeiro Trimestre da Gravidez
10.
Prenat Diagn ; 35(7): 717-23, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25828703

RESUMO

OBJECTIVE: The aim of this retrospective study was to describe the sonographic appearance of the posterior brain anatomy in normal fetuses at 11 to 14 weeks of pregnancy and to determine the fetal outcome when one of the posterior brain anatomical space is not recognized. METHODS: Two groups of patients were included in the study: a control group of consecutive 311 healthy fetuses with a normal sonogram and a study group of 21 fetuses with absence of one of the three posterior brain spaces. In each fetus, images of the mid-sagittal view of the fetal face and brain at 11 to 14 weeks of gestation were obtained. RESULTS: In all fetuses with absence of one of the three posterior brain spaces, a severe anomaly, including open spina bifida, cephalocele, Dandy-Walker complex, and chromosomal aberrations, was associated. CONCLUSION: Our study indicates that the sonographic finding characterized by the absence of one of the three posterior brain spaces seems to facilitate not only the detection of open spina bifida, as previously reported, but also of other neural tube defects, such as cephalocele, and is an important risk factor for cystic posterior brain anomalies, and/or chromosomal abnormalities. Thus it seems a poor prognostic finding for major fetal abnormalities.


Assuntos
Tronco Encefálico/diagnóstico por imagem , Transtornos Cromossômicos/diagnóstico por imagem , Cisterna Magna/diagnóstico por imagem , Síndrome de Dandy-Walker/diagnóstico por imagem , Quarto Ventrículo/diagnóstico por imagem , Defeitos do Tubo Neural/diagnóstico por imagem , Ultrassonografia Pré-Natal , Tronco Encefálico/anormalidades , Estudos de Casos e Controles , Cisterna Magna/anormalidades , Encefalocele/diagnóstico por imagem , Feminino , Quarto Ventrículo/anormalidades , Idade Gestacional , Humanos , Gravidez , Resultado da Gravidez , Primeiro Trimestre da Gravidez , Estudos Retrospectivos , Espinha Bífida Cística/diagnóstico por imagem
12.
Leukemia ; 28(9): 1804-10, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24549259

RESUMO

We recently defined a high-molecular risk category (HMR) in primary myelofibrosis (PMF), based on the presence of at least one of the five 'prognostically detrimental' mutated genes (ASXL1, EZH2, SRSF2 and IDH1/2). Herein, we evaluate the additional prognostic value of the 'number' of mutated genes. A total of 797 patients were recruited from Europe (n=537) and the Mayo Clinic (n=260). In the European cohort, 167 (31%) patients were HMR: 127 (23.6%) had one and 40 (7.4%) had two or more mutated genes. The presence of two or more mutations predicted the worst survival: median 2.6 years (hazard ratio (HR) 3.8, 95% confidence interval (CI) 2.6-5.7) vs. 7.0 years (HR 1.9, 95% CI 1.4-2.6) for one mutation vs 12.3 years for no mutations. The results were validated in the Mayo cohort and prognostic significance in both cohorts was independent of International Prognostic Scoring System (IPSS; HR 2.4, 95% CI 1.6-3.6) and dynamic IPSS (DIPSS)-plus (HR 1.9, 95% CI 1.2-3.1), respectively. Two or more mutations were also associated with shortened leukemia-free survival (HR 6.2, 95% CI 3.5-10.7), also Mayo validated. Calreticulin mutations favorably affected survival, independently of both number of mutations and IPSS/DIPSS-plus. We conclude that the 'number' of prognostically detrimental mutations provides added value in the combined molecular and clinical prognostication of PMF.


Assuntos
Mutação , Mielofibrose Primária/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Calreticulina/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mielofibrose Primária/mortalidade , Prognóstico , Proteínas Repressoras/genética
13.
Leukemia ; 28(5): 1052-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24150215

RESUMO

With the intent of dissecting the molecular complexity of Philadelphia-negative myeloproliferative neoplasms (MPN), we designed a target enrichment panel to explore, using next-generation sequencing (NGS), the mutational status of an extensive list of 2000 cancer-associated genes and microRNAs. The genomic DNA of granulocytes and in vitro-expanded CD3+T-lymphocytes, as a germline control, was target-enriched and sequenced in a learning cohort of 20 MPN patients using Roche 454 technology. We identified 141 genuine somatic mutations, most of which were not previously described. To test the frequency of the identified variants, a larger validation cohort of 189 MPN patients was additionally screened for these mutations using Ion Torrent AmpliSeq NGS. Excluding the genes already described in MPN, for 8 genes (SCRIB, MIR662, BARD1, TCF12, FAT4, DAP3, POLG and NRAS), we demonstrated a mutation frequency between 3 and 8%. We also found that mutations at codon 12 of NRAS (NRASG12V and NRASG12D) were significantly associated, for primary myelofibrosis (PMF), with highest dynamic international prognostic scoring system (DIPSS)-plus score categories. This association was then confirmed in 66 additional PMF patients composing a final dataset of 168 PMF showing a NRAS mutation frequency of 4.7%, which was associated with a worse outcome, as defined by the DIPSS plus score.


Assuntos
Exoma , Mutação em Linhagem Germinativa , Transtornos Mieloproliferativos/genética , Neoplasias/genética , Estudos de Coortes , Humanos
14.
Biochem Biophys Res Commun ; 347(2): 452-9, 2006 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-16824484

RESUMO

It has been shown that when CFTR and NHE3 are co-expressed on the apical membrane of the A6-NHE3 cell monolayers, the two transporters interact via a shared regulatory complex composed of NHERF2, ezrin, and PKA. We observe here that co-expression of NHE3 reduced both PKA-dependent apical CFTR expression and its activation once in place by approximately 50%. To analyze the role of NHERF2 in this process, we transfected NHE3 expressing and non-expressing A6 monolayers with NHERF2 cDNA in which its binding domains had been deleted. When only CFTR is expressed on the apical membrane, deletion of any of the NHERF2 binding domains inhibited both PKA-dependent apical CFTR expression and its activation, while when NHE3 was co-expressed with CFTR PDZ2 deletion was without effect on CFTR sorting and activity. This suggests that when the PDZ2 domain is "sequestered" by interacting with NHE3 it can no longer participate in CFTR functional expression.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Proteínas do Citoesqueleto/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Animais , Sítios de Ligação/genética , Western Blotting , Linhagem Celular , Colforsina/farmacologia , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/fisiologia , Mutação , Néfrons/citologia , Néfrons/metabolismo , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Trocador 3 de Sódio-Hidrogênio , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/fisiologia , Transfecção , Xenopus laevis
15.
Pflugers Arch ; 449(1): 66-75, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15235914

RESUMO

Nucleotide binding to purinergic P2Y receptors contributes to the regulation of a variety of physiological functions in renal epithelial cells. Here, we investigate the regulatory mechanism of the P2Y1 receptor agonist 2-methylthioadenosine diphosphate (2-MeSADP) on Cl- transport in A6 cells, a commonly used model of the distal section of the Xenopus laevis nephron. Protein and mRNA expression analysis together with functional measurements demonstrated the basolateral location of the Xenopus P2Y1 receptor. 2-MeSADP increased intracellular [Ca2+] and cAMP and Cl- efflux, responses that were all inhibited by the specific P2Y1 receptor antagonist MRS 2179. Cl- efflux was also inhibited by the cystic fibrosis transmembrane conductance regulator (CFTR) blocker glibenclamide. Inhibition of either protein kinase A (PKA) or the binding between A-kinase-anchoring proteins (AKAPs) and the regulatory PKA RII subunit blocked the 2-MeSADP-induced activation of CFTR, suggesting that PKA mediates P2Y1 receptor regulation of CFTR through one or more AKAPs. Further, the truncation of the PDZ1 domain of the scaffolding protein Na+/H+ exchanger regulatory factor-2 (NHERF-2) inhibited 2-MeSADP-dependent stimulation of Cl- efflux, suggesting the involvement of this scaffolding protein. Activation or inhibition of PKC had no effect per se on basal Cl- efflux but potentiated or reduced the 2-MeSADP-dependent stimulation of Cl- efflux, respectively. These data suggest that the X laevis P2Y1 receptor in A6 cells can increase both cAMP/PKA and Ca2+/PKC intracellular levels and that the PKC pathway is involved in CFTR activation via potentiation of the PKA pathway.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Células Epiteliais/metabolismo , Fosfoproteínas/metabolismo , Receptores Purinérgicos P2/metabolismo , Difosfato de Adenosina/análogos & derivados , Difosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Linhagem Celular , Cloretos/metabolismo , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Células Epiteliais/citologia , Glibureto/metabolismo , Indometacina/metabolismo , Isoquinolinas/metabolismo , Túbulos Renais/citologia , Antagonistas do Receptor Purinérgico P2 , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2Y1 , Trocadores de Sódio-Hidrogênio , Sulfonamidas/metabolismo , Tionucleotídeos/metabolismo , Xenopus laevis
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