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OBJECTIVE: To contribute to clarify molecular mechanisms supporting senescence and de-differentiation of chondrocytes in chondrocyte pathologies such as osteoarthritis (OA). Specifically, we investigated the relationship between the nuclear lamina protein Lamin B1 and the negative regulator of chondrogenesis Slug transcription factor in osteoarthritic chondrocytes. METHODS: Lamin B1 and Slug proteins were analyzed in cartilage explants from normal subjects and OA patients by immunohistochemical technique. Their expression was confirmed on isolated chondrocytes both at passage 0 and passage 2 (de-differentiated chondrocytes) by immunofluorescence and western blot. Subsequently, we explored the "in vivo" binding of Slug on LMNB1 promoter by chromatin immunoprecipitation assay (ChIP). RESULTS: In this study we demonstrated that nuclear lamina protein Lamin B1 and anti-chondrogenic Slug transcription factor are upregulated in cartilage and OA chondrocytes. Furthermore, we found that Slug is "in vivo" recruited by LMNB1 gene promoter mostly when chondrocytes undergo de-differentiation or OA degeneration. CONCLUSIONS: We described for the first time a potential regulatory role of Slug on the LMNB1 gene expression in OA chondrocytes. These findings may have important implications for the study of premature senescence, and degeneration of cartilage, and may contribute to develop effective therapeutic strategies against signals supporting cartilage damage in different subsets of patients.
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Condrocitos/metabolismo , Laminina/biosíntesis , Osteoartritis de la Rodilla/metabolismo , Factores de Transcripción/biosíntesis , Anciano , Cartílago Articular/metabolismo , Núcleo Celular/metabolismo , Células Cultivadas , Femenino , Humanos , Articulación de la Rodilla/metabolismo , Laminina/genética , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/genética , Factores de Transcripción de la Familia Snail , Factores de Transcripción/genética , Regulación hacia ArribaRESUMEN
BACKGROUND AND OBJECTIVE: Bioreactors are devices that efficiently create an environment that enables cell cultures to grow in a three-dimensional (3D) context mimicking in vivo conditions. In this study, we investigate the effect of dynamic fluid flow on the osteogenic potential of human mesenchymal stem cells obtained from periodontal ligament and entrapped in alginate microbeads. MATERIAL AND METHODS: After proper immunophenotyping, cells were encapsulated in barium alginate, cultured in 3D static or 3D dynamic conditions represented by a bioreactor system. Calcein-AM/propidium iodide staining was used to assess cellular viability. Quantitative real-time polymerase chain reaction was used to analyze the expression of osteogenic markers (Runx2 and COL1). Alizarin Red S staining and the Fourier transform infrared spectroscopy were used to assess mineral matrix deposition. RESULTS: Optimal encapsulation procedure, in terms of polymer pumping rate, distance from droplet generator to the gelling bath and atomizing airflow was assessed. Cell viability was not affected by encapsulation in alginate microbeads. Bioreactor cell exposure was effective in anticipating osteogenic differentiation and improving mineral matrix deposition. CONCLUSION: For the first time human mesenchymal stem cells obtained from periodontal ligaments encapsulated in alginate microbeads were cultured in a bioreactor system. This combination could represent a promising strategy to create a cell-based smart system with enhanced osteogenic potential useful for many different dental applications.
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Alginatos , Materiales Biocompatibles , Células Madre Mesenquimatosas/fisiología , Osteogénesis/fisiología , Ligamento Periodontal/citología , Andamios del Tejido , Adipogénesis/fisiología , Alginatos/química , Apatitas/análisis , Materiales Biocompatibles/química , Reactores Biológicos , Técnicas de Cultivo de Célula , Diferenciación Celular/fisiología , Supervivencia Celular/fisiología , Condrogénesis/fisiología , Colágeno Tipo I/análisis , Cadena alfa 1 del Colágeno Tipo I , Subunidad alfa 1 del Factor de Unión al Sitio Principal/análisis , Matriz Extracelular/química , Ácido Glucurónico/química , Ácidos Hexurónicos/química , Humanos , Hidrodinámica , Microesferas , Propiedades de Superficie , Andamios del Tejido/química , Gelatina de Wharton/citologíaRESUMEN
The Lynch syndrome (LS) is an autosomal dominant condition usually characterized by germline pathogenic variants in DNA mismatch repair (MMR) genes. Despite the guidelines now available, determining the pathogenicity of rare variants remains challenging, as the clinical significance of a genetic variant could be uncertain, but it may represent a disease-associated variation in the aforementioned genes. In this case report we will describe the case of a 47 years-old female affected by endometrial cancer (EC) with an extremely rare germline heterozygous variant in the MSH2 gene (c.562G > T p. (Glu188Ter), exon 3) that is likely pathogenic, and a family history consistent with LS.
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Oscillatory swimming of a fishlike body, whose motion is essentially promoted by the flapping tail, has been studied almost exclusively in axial mode under an incoming uniform stream or, more recently, self-propelled under a virtual body resistance. Obviously, both approaches do not consider the unavoidable recoil motions of the real body which have to be necessarily accounted for in a design procedure for technological means. Actually, once combined with the prescribed kinematics of the tail, the recoil motions lead to a remarkable improvement on the resulting swimming performance. An inviscid impulse model, linear in both potential and vortical contributions, is a proper tool to obtain a deeper comprehension of the physical events with respect to more elaborated flow interaction models. In fact, at a first look, the numerical results seem to be quite entangled, since their trends in terms of the main flapping parameters are not easy to be identified and a fair interpretation is obtained by means of the model capability to separate the effects of added mass and vortex shedding. Specifically, a prevailing dependence of the potential contribution on the heave amplitude and of the vortical contribution on the pitch amplitude is instrumental to unravel their combined action. A further aid for a proper interpretation of the data is provided by accounting separately for a geometrical component of the recoil which is expected to follow from the annihilation of any spurious rigid motion in case no fluid interactions occur. The above detailed decomposition of the recoil motions shows, through the numerical results, how the single components are going to influence the main flapping parameters and the locomotion performance as a guide for the design of biomimetic swimmers.
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Enfermedad Pulmonar Obstructiva Crónica , Natación , Humanos , Locomoción , Biomimética , Movimiento (Física)RESUMEN
BACKGROUND: The research addressed to detect new molecular targets in the development of therapeutic strategies aimed to repair bone tissues. The AIM OF THIS STUDY was to determine the potential osteogenic activity of bone cells from the nasal septum and their use to perform accurate molecular analysis from a single sample. METHODOLOGY: The cells, after nasal septum surgery, were subjected to gene silencing, Reverse Transcriptase - Polymerase Chain reactions, immunocytochemistry and chromatin immunoprecipitation. RESULTS: Cells from the nasal septum can give rise to mature osteoblasts that express osteogenic markers (ALP, Runx2, Slug) and are able to mineralize. We demonstrated that Runx2, a transcription factor critical in early osteospecific differentiation, interacts in vivo with the promoter of the SLUG gene, a marker of osteoblast maturation. CONCLUSIONS: We demonstrated that nasal septum-derived osteoblasts represent an interesting alternative source for bone forming cells, and a promising material to be utilized in bone cellular therapy.
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Tabique Nasal/citología , Osteogénesis/fisiología , Ingeniería de Tejidos/métodos , Adulto , Anciano , Inmunoprecipitación de Cromatina , Subunidad alfa 1 del Factor de Unión al Sitio Principal , Femenino , Citometría de Flujo , Silenciador del Gen , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Osteoblastos/fisiología , ARN Interferente Pequeño/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción de la Familia Snail , Factores de Transcripción , TransfecciónRESUMEN
The present study evaluated human primary osteoblasts and two different osteoblast-like cell lines behaviour when cultured in presence of different hydroxyapatite-based (HA) biomaterials (SINTlife-FIN-CERAMICA S.p.a., Faenza, Italy; Bio-Oss, Geistlich Biomaterials, Woulhusen, Switzerland; Biostite-GABA Vebas, San Giuliano Milanese, MI, Italy), focusing attention on the effect of HA/Biostite in terms of modulation of osteoblastic differentiation. Analysis were about adhesion, proliferation and mineralization activity. Runt-related transcription factor 2 (Runx2), Estrogen Receptor alpha (ERalfa) expression and alkaline phosphatase activity (ALP) were measured as osteoblastic differentiation markers. Determination of viable cells was done with MTT colorimetric assay. Scanning electron microscopy (SEM) analysis was performed on biomaterial-treated cells. All hydroxyapatite-based biomaterials didn't affect cells morphology and viability, whereas only presence of HA/Biostite improved cells adhesion, growth and differentiation. Adhesion and spreading of the primary cells on HA/Biostite were the same showed by two different osteoblast-like cell lines. These results have important implications for both tissue-engineered bone grafts and enhancement of HA implants performance, to develop new teeth's supporting structure therapies and replacement.
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Materiales Biocompatibles/farmacología , Durapatita/farmacología , Osteoblastos/efectos de los fármacos , Células Cultivadas , Humanos , FenotipoRESUMEN
Even if NOTCH1 is commonly mutated in chronic lymphocytic leukemia (CLL), its functional impact in the disease remains unclear. Using CRISPR/Cas9-generated Mec-1 cell line models, we show that NOTCH1 regulates growth and homing of CLL cells by dictating expression levels of the tumor suppressor gene DUSP22. Specifically, NOTCH1 affects the methylation of DUSP22 promoter by modulating a nuclear complex, which tunes the activity of DNA methyltransferase 3A (DNMT3A). These effects are enhanced by PEST-domain mutations, which stabilize the molecule and prolong signaling. CLL patients with a NOTCH1-mutated clone showed low levels of DUSP22 and active chemotaxis to CCL19. Lastly, in xenograft models, NOTCH1-mutated cells displayed a unique homing behavior, localizing preferentially to the spleen and brain. These findings connect NOTCH1, DUSP22, and CCL19-driven chemotaxis within a single functional network, suggesting that modulation of the homing process may provide a relevant contribution to the unfavorable prognosis associated with NOTCH1 mutations in CLL.
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Quimiocina CCL19/fisiología , Fosfatasas de Especificidad Dual/genética , Leucemia Linfocítica Crónica de Células B/patología , Fosfatasas de la Proteína Quinasa Activada por Mitógenos/genética , Receptor Notch1/genética , Línea Celular , Movimiento Celular , Quimiotaxis , ADN (Citosina-5-)-Metiltransferasas/metabolismo , ADN Metiltransferasa 3A , Regulación Neoplásica de la Expresión Génica , Genes Supresores de Tumor , Xenoinjertos , Humanos , Leucemia Linfocítica Crónica de Células B/genética , Mutación , Dominios Proteicos/genéticaAsunto(s)
Esclerosis Amiotrófica Lateral/patología , Apoptosis , Neuronas Motoras/patología , Envejecimiento , Sustitución de Aminoácidos , Esclerosis Amiotrófica Lateral/enzimología , Esclerosis Amiotrófica Lateral/genética , Animales , Núcleo Celular/metabolismo , Núcleo Celular/patología , Fragmentación del ADN , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Transgénicos , Neuronas Motoras/enzimología , Neuronas Motoras/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismoRESUMEN
A c-myc DNA with a deletion which includes 5' flanking, exon 1 and intron I sequences has been found in normal white blood cells of a mother and one daughter in a Northern Italian family. In addition, the degree of methylation of specific CCGG sites in the truncated DNA is lower in both mother and daughter than that found in normal DNA. It is of interest that deletions of the first exon and hypomethylation of the c-myc gene have usually been observed only in some neoplasias. However, our results demonstrate that the c-myc truncated DNA with the abnormal methylation pattern here reported is a genomic variant which by itself is not related to neoplastic transformation.
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Deleción Cromosómica , ADN/química , Exones/genética , Genes myc/genética , Mapeo Cromosómico , Femenino , Humanos , Intrones , Italia , Metilación , LinajeRESUMEN
It is well known that breast carcinomas without estrogen receptor (ER) have a poor prognosis and do not respond to endocrine therapy. In analyzing the question of the lack of ER gene expression, we have considered the possibility that specific negative transcription factors are present in ER-negative breast cancers. Inside the P3 upstream promoter of human ER gene we identified a transcriptional regulatory sequence able to bind protein factors expressed in ER-negative MDA-MB-231 breast cancer cells. This sequence, lying between nucleotides -3258 to -3157, seems to be critical for inhibition of ER gene transcription. In fact, the selected sequence in the form of double-stranded DNA has been introduced into ER-negative breast cancer cells as 'decoy' cis elements showing the ability to remove the putative negative transcription factor(s) and to induce the reactivation of ER gene transcription. In addition, in transient transfection assays the selected sequence decreased the SV-40 promoted luciferase activity. Gel shift assays identified multiple DNA-protein interactions which specifically form in this region, and data from Southwestern experiments strongly suggested the presence of a specific protein expressed in MDA-MB-231 ER-negative, but not in MCF7 ER-positive cells.
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Regulación de la Expresión Génica , Regiones Promotoras Genéticas/genética , Receptores de Estrógenos/genética , Secuencia de Bases , ADN/análisis , Silenciador del Gen/fisiología , Humanos , Células K562 , Datos de Secuencia Molecular , Células Tumorales CultivadasRESUMEN
The receptor for transferrin plays an important role both in tumor cell growth and in hemoglobin synthesis. In this paper, we demonstrate that the monoclonal antibody 42/6 to human transferrin receptor inhibits iron uptake in the human leukemic K562 cell line and suppresses hemoglobin accumulation in K562 cells induced to erythroid differentiation by butyric acid. In contrast, only slight inhibitory effects were observed on cell proliferation of both uninduced and erythroid-induced K562 cells treated with the 42/6 monoclonal antibody. In addition, the 42/6 monoclonal antibody to human transferrin receptor does not inhibit butyric acid-induced accumulation of gamma-globin mRNA. The effect of the 42/6 monoclonal antibody on hemoglobin synthesis appears to be restricted to human cell lines, as murine Friend erythroleukemic cells undergo erythroid differentiation when cultured in the presence of hexamethylenebisacetamide plus the 42/6 monoclonal antibody. The findings reported in this paper suggest (a) a dissociation of iron transport and accumulation of heme molecules from the expression of globin genes and (b) a different requirement of iron uptake by different iron-dependent functions such as cell proliferation and hemoglobin expression.
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Anticuerpos Monoclonales/inmunología , Hemoglobinas/biosíntesis , Leucemia Mieloide/metabolismo , Receptores de Superficie Celular/fisiología , Butiratos/farmacología , Ácido Butírico , Diferenciación Celular/efectos de los fármacos , División Celular , Línea Celular , Eritropoyesis , Globinas/genética , Humanos , Hierro/metabolismo , Leucemia Mieloide/patología , ARN Mensajero/análisis , Receptores de Superficie Celular/inmunología , Receptores de TransferrinaRESUMEN
OBJECTIVES: The goal of this study was to determine the effects of exercise training (ET) on functional capacity and quality of life (QOL) in patients who received percutaneous transluminal coronary angioplasty (PTCA) or coronary stenting (CS), the effects on the restenosis rate and the outcome. BACKGROUND: It is unknown whether ET induces beneficial effects after coronary angioplasty. METHODS: We studied 118 consecutive patients with coronary artery disease (mean age 57+/-10 years) who underwent PTCA or CS on one (69%) or two (31%) native epicardial coronary arteries. Patients were randomized into two matched groups. Group T (n = 59) was exercised three times a week for six months at 60% of peak VO2. Group C (n = 59) was the control group. RESULTS: Only trained patients had significant improvements in peak VO2 (26%, p < 0.001) and quality of life (26.8%, p = 0.001 vs. C). The angiographic restenosis rate was unaffected by ET (T: 29%; C: 33%, P = NS) and was not significantly different after PTCA or CS. However, residual diameter stenosis was lower in trained patients (-29.7%, p = 0.045). In patients with angiographic restenosis, thallium uptake improved only in group T (19%; p < 0.001). During the follow-up (33+/-7 months) trained patients had a significantly lower event rate than controls (11.9 vs. 32.2%, RR: 0.71, 95% confidence interval [CI]: 0.60 to 0.91, p = 0.008) and a lower rate of hospital readmission (18.6 vs. 46%, RR: 0.69, 95% CI: 0.55 to 0.93, p < 0.001). CONCLUSIONS: Moderate ET improves functional capacity and QOL after PTCA or CS. During the follow-up, trained patients had fewer events and a lower hospital readmission rate than controls, despite an unchanged restenosis rate.
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Angioplastia Coronaria con Balón/rehabilitación , Enfermedad Coronaria/terapia , Ejercicio Físico , Calidad de Vida , Stents , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios Prospectivos , RecurrenciaRESUMEN
To define a role for the angiopoietin/Tie2 system in astrocytoma angiogenesis, we examined the expression of angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) in these tumors by immunohistochemistry and in situ hybridization. Furthermore, we studied in vitro the effects elicited by glioblastoma cell-secreted Ang1 or by recombinant Ang1 on functions of endothelial cells (ECs). Our observations of astrocytomas show that a stage-specific induction of angiopoietins occurs and is correlated with angiogenic phases of different intensity. Ang1 expression was found in a few astrocytes scattered in the tumor at all stages of astrocytoma progression. In blood vessels, Ang1 mRNA increased progressively in high-grade glioblastomas, in which the number of vessels was higher than in low-grade tumors. Ang2 was detected in tumor cells and in ECs in high-grade astrocytomas, whereas its expression was negligible in low-grade tumors. Coculture of glioblastoma cell lines producing Ang1 with endothelium demonstrated a key role of this ligand in the control of EC network organization. We found that recombinant Ang1 in vitro induces EC spreading and reorganization of the cell monolayer into cordlike structures. These results suggest that Ang1 directly acts on ECs by modulating cell-cell and cell-matrix associations and promoting the differentiation phase of angiogenesis.
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Inductores de la Angiogénesis/metabolismo , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Glicoproteínas de Membrana/biosíntesis , Neovascularización Patológica/metabolismo , Inductores de la Angiogénesis/fisiología , Angiopoyetina 1 , Angiopoyetina 2 , Astrocitoma/genética , Astrocitoma/metabolismo , Línea Celular , Glioblastoma/irrigación sanguínea , Glioblastoma/genética , Humanos , Inmunohistoquímica , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/farmacología , Biosíntesis de Proteínas , Proteínas/metabolismo , Proteínas/farmacología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Células Tumorales CultivadasRESUMEN
The purpose of this study is to evaluate the efficacy of yttria-stabilized zirconia (3Y-TZP) as an inert phase to prevent the decomposition of Bi2 V0.9 Cu0.1 O5.5 -δ (BICUVOX.1) electrolyte under reducing atmosphere. A post-mortem scanning electron microscopy (SEM) study was performed after chemical stability tests under hydrogen-rich atmosphere using a Sieverts-type apparatus. SEM results showed that BICUVOX.1 decomposition starts under a hydrogen pressure of 19.7 atm at 300°C, even in the case of the composite containing 3Y-TZP. The microstructure of BICUVOX.1 after decomposition was observed to be composed of microspheres ranging from 10 to 100 µm formed primarily of metallic bismuth. In the composite, in addition to microspheres, the microstructure contained bismuth fibers growth from the grain area of the BICUVOX.1 matrix. Despite significant surface morphological modifications, the grain-boundary-arranged 3Y-TZP particles in a BICUVOX.1-matrix composite did not result in enhanced chemical stability.
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Although anaplastic large-cell lymphomas (ALCL) carrying anaplastic lymphoma kinase (ALK) have a relatively good prognosis, aggressive forms exist. We have identified a novel translocation, causing the fusion of the TRAF1 and ALK genes, in one patient who presented with a leukemic ALK+ ALCL (ALCL-11). To uncover the mechanisms leading to high-grade ALCL, we developed a human patient-derived tumorgraft (hPDT) line. Molecular characterization of primary and PDT cells demonstrated the activation of ALK and nuclear factor kB (NFkB) pathways. Genomic studies of ALCL-11 showed the TP53 loss and the in vivo subclonal expansion of lymphoma cells, lacking PRDM1/Blimp1 and carrying c-MYC gene amplification. The treatment with proteasome inhibitors of TRAF1-ALK cells led to the downregulation of p50/p52 and lymphoma growth inhibition. Moreover, a NFkB gene set classifier stratified ALCL in distinct subsets with different clinical outcome. Although a selective ALK inhibitor (CEP28122) resulted in a significant clinical response of hPDT mice, nevertheless the disease could not be eradicated. These data indicate that the activation of NFkB signaling contributes to the neoplastic phenotype of TRAF1-ALK ALCL. ALCL hPDTs are invaluable tools to validate the role of druggable molecules, predict therapeutic responses and implement patient specific therapies.
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Resistencia a Antineoplásicos , Linfoma Anaplásico de Células Grandes/genética , FN-kappa B/metabolismo , Proteínas Tirosina Quinasas Receptoras/genética , Factor 1 Asociado a Receptor de TNF/genética , Translocación Genética/genética , Quinasa de Linfoma Anaplásico , Animales , Western Blotting , Citometría de Flujo , Perfilación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Inmunoprecipitación , Hibridación Fluorescente in Situ , Linfoma Anaplásico de Células Grandes/tratamiento farmacológico , Linfoma Anaplásico de Células Grandes/mortalidad , Ratones , Ratones Endogámicos NOD , FN-kappa B/genética , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Inhibidores de Proteasoma/farmacología , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteínas Tirosina Quinasas Receptoras/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Factor 1 Asociado a Receptor de TNF/metabolismo , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Autosomal dominant polycystic kidney disease (ADPKD) is a common disorder mostly characterized by cyst formation in kidney tubules. The majority of ADPKD cases is caused by mutations in the PKD1 gene, but no prevalent mutation has been reported. By heteroduplex analysis of the 3' single-copy region of the gene, we have searched for mutations in subjects from 40 ADPKD families of Northern Italy. Seven novel polymorphisms and three novel disease-associated mutations (R3718Q, L3851P and IVS45+56del25) were identified. Both missense mutations are located in the major extracellular loop of polycystin-1. The 25 bp deletion inside intron 45 did not affect 5' and 3' consensus splicing sites, but caused a 56 nucleotide out of frame-deletion due to activation of a cryptic 3' splice site in exon 46. The mutated RNA should produce a truncated polycystin 1 at the G binding peptide in the intracellular C-terminal end of the protein. RT-PCR analysis showed that the disease-associated mutations were present in transcribed sequences. In particular, RNA analysis of BHK cells transfected with PKD1 genomic DNA, including the deleted intron, showed that no normal transcript is produced by the deleted gene. This intronic mutation, found in a large pedigree, seems to be associated with a prevalence of cerebrovascular disease.
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Empalme Alternativo/genética , Expresión Génica/genética , Mutación Missense/genética , Riñón Poliquístico Autosómico Dominante/genética , Biosíntesis de Proteínas , Proteínas/genética , Adulto , Anciano , Secuencia de Bases/genética , Femenino , Humanos , Fallo Renal Crónico/genética , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Polimorfismo Genético , Isoformas de Proteínas/genética , Canales Catiónicos TRPPRESUMEN
There is increasing evidence that oxidative damage plays a major role in amyotrophic lateral sclerosis (ALS), but how it contributes to motor neuron degeneration and astrocytic gliosis, two pathologic hallmarks of the disease, is unknown. A few studies have suggested that ALS motor neurons die via apoptosis and show upregulation of c-jun, an immediate early gene that is necessary for neuronal apoptosis. In order to elucidate the mechanisms of cell damage induced by oxidant stress, we have studied in ALS and control spinal cord the immunohistochemical expression of c-Jun, of JNK/SAPK, a kinase that activates c-Jun following various types of stress, and of NF-kappa B, a transcription factor that is induced by oxidant stress and has prominent neuroprotective functions. An in situ end-labeling assay was performed for detecting apoptotic cells. We show that (a) the JNK/SAPK-c-Jun pathway is dramatically overexpressed in ALS spinal cord; (b) the strongest activation occurs in astrocytes, while motor neurons show unusually low expression of the pathway; (c) increased JNK/SAPK expression in glial cells is accompanied by NF-kappa B activation, indicating the presence of a protective response to oxidant sress, which is deficient in motor neurons; (d) activation of JNK/SAPK, c-Jun and NF-kappa B is unrelated to apoptotic cell death. These results support the view that astrocytes are directly involved in the pathologic process of ALS, and might explain the selective vulnerability of motor neurons by their relative lack of antioxidant defenses.
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Esclerosis Amiotrófica Lateral/metabolismo , Astrocitos/metabolismo , Proteínas Quinasas JNK Activadas por Mitógenos , Quinasas de Proteína Quinasa Activadas por Mitógenos , Proteínas Quinasas Activadas por Mitógenos , Neuronas Motoras/metabolismo , FN-kappa B/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-jun/metabolismo , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/patología , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Fragmentación del ADN , Humanos , Inmunohistoquímica , MAP Quinasa Quinasa 4 , Persona de Mediana Edad , Proteína Quinasa 12 Activada por Mitógenos , Proteína Quinasa 9 Activada por Mitógenos , Proteínas Quinasas p38 Activadas por MitógenosRESUMEN
p27/kip1 regulates the G1-S transition of the cell cycle by inhibiting cyclin D-CDK4, cyclin E-CDK2, and cyclin A-CDK2. Modulation of p27 cellular abundance occurs mainly at post-translational level by the ubiquitin-proteasome proteolysis. Although rearrangements and mutations of p27/kip1 are extremely rare events, p27 levels are reduced and associated with a poor prognosis in many human carcinomas. In astrocytic tumors, p27 decreases with advancing anaplasia and is almost absent in glioblastomas. To verify whether the degradation of p27 protein was responsible for its reduced levels in malignant gliomas, p27 degradation activity was tested in 22 tissue extracts that represented high, low, and absent p27 protein levels. p27 protein expression was detected by immunohistochemistry and immunoblot analysis and comparable results between the 2 methods were obtained. Low or undetectable p27 degradation activity was found in samples that displayed high levels of p27, i.e. all 4 normal brain biopsies, and 4 out of 6 grade II astrocytomas. Enhanced degradation activity resulted in malignant gliomas with low or absent p27 protein levels. The proteasome inhibitor LLnL abolished p27 degradation, demonstrating that it occurs in a proteasome-dependent manner. These data suggest that proteasome degradation of p27 may be instrumental in the deregulation of the cell cycle and to the malignant transformation of gliomas.
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Neoplasias Encefálicas/metabolismo , Cisteína Endopeptidasas/metabolismo , Glioma/metabolismo , Proteínas de Microfilamentos/metabolismo , Complejos Multienzimáticos/metabolismo , Proteínas Musculares , Astrocitoma/metabolismo , Glioblastoma/metabolismo , Humanos , Immunoblotting , Inmunohistoquímica , Oligodendroglioma/metabolismo , Complejo de la Endopetidasa ProteasomalRESUMEN
JNK and p38, two members of the MAP kinase family, are strongly induced by various stresses including oxidative stress and have been involved in regulation of apoptosis. As both kinases phosphorylate tau protein in vitro, we have investigated their immunohistochemical localization in a group of neurodegenerative diseases characterized by intracellular deposits of hyperphosphorylated tau. Cases included Alzheimer disease, Pick disease, progressive supranuclear palsy, corticobasal degeneration, Gerstmann-Sträussler-Scheinker disease-Indiana kindred, and frontotemporal dementia with parkinsonism linked to chromosome 17. In all tissue samples, strong immunoreactivity for both MAP kinases was found in the same neuronal or glial cells that contained tau-positive deposits. By double immunohistochemistry, JNK and p38 colocalized with tau in the inclusions. Analysis of apoptosis-related changes (DNA fragmentation, activated caspase-3) showed that the expression of JNK and p38 was unrelated to activation of an apoptotic cascade. Our data indicate that phospho-JNK and phospho-p38 are associated with hyperphosphorylated tau in a variety of abnormal tau inclusions, suggesting that these kinases may play a role in the development of degenerative diseases with tau pathology.
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Apoptosis , Proteínas Quinasas JNK Activadas por Mitógenos , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Transducción de Señal/fisiología , Tauopatías/enzimología , Proteínas tau/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/enzimología , Enfermedad de Alzheimer/patología , Encéfalo/enzimología , Encéfalo/patología , Activación Enzimática , Humanos , MAP Quinasa Quinasa 4 , Persona de Mediana Edad , Neuronas/enzimología , Neuronas/patología , Fosforilación , Tauopatías/patología , Proteínas Quinasas p38 Activadas por MitógenosRESUMEN
A mutation in the gene Girk2 that encodes an inwardly rectifying potassium channel is the genetic defect causing the behavioral and pathologic abnormalities of the weaver mutant mouse. Of the pathologic abnormalities, the best studied is the neuronal degeneration that occurs in the cerebellar cortex and in the midbrain dopaminergic neurons. A detailed characterization of the topographic and temporal expression of Girk2 is fundamental to elucidate the mechanisms underlying neurodegeneration in these mutant mice. In this study we utilized in situ hybridization to determine the expression of Girk2 mRNA during prenatal and postnatal development in the murine central nervous system (CNS). Girk2 expression was seen in multiple regions of embryonic CNS including the cerebellum and midbrain. During postnatal development, the highest expression was seen in the cerebellum, midbrain and hippocampus. However, since the developing cerebellum undergoes significant neuronal loss due to the degeneration of granule cell precursors, Girk2 mRNA expression in this area decreases progressively.