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BACKGROUND: Olfactory dysfunctions (OD) and taste dysfunctions (TD) are widely recognized as characteristic symptoms of COVID-19; however, the frequency and mode of occurrence has varied depending on the viral mutation. The prevalence and characteristics of OD/TD in Japan have not been definitively investigated. The purpose of this study is to assess the prevalence of OD/TD in Japan during the Alpha variant epidemic, and measure symptom prolongation at 6 months and 1 year later following initial infection. METHODS: Patients treated for COVID-19 between February to May 2021 were evaluated for OD/TD symptoms and provided with a QOL questionnaire. Olfactory tests and taste tests were performed using Open Essence and Taste Strips, respectively. RESULTS: Among the 251 COVID-19 patients who participated, 119 underwent both olfactory and taste tests. Prevalence of subjective OD and TD at the time of survey was 57.8% and 40.2%, respectively. After 12 months, the prevalence fell to 5.8% for OD and 3.5% for TD. Among the OD/TD patients, 36.6% experienced parosmia, and 55.4% experienced parageusia. Prevalence of parosmia and parageusia was higher at 6 and 12 months than at the time of survey. Patients with long-lasting disease reported qualitative dysfunctions and scored significantly higher in food-related QOL problems. Most patients who were aware of their hyposmia had low scores on the olfactory test (83.1%). In contrast, only 26.7% of patients who were aware of their hypogeusia had low scores on the taste test. CONCLUSIONS: The prevalence of COVID-19-related OD and TD at the time of survey was 57.8% and 40.2%, respectively. Subjective symptoms of OD and TD persisted for one year in 5.8% and 3.5% of patients, respectively. More than half of the patients with OD or TD complained of qualitative dysfunction and a decrease in their QOL related to eating and drinking. Most patients with TD did not have true TD, but rather developed flavour disorders associated with OD. This conclusion is supported by the finding that patients with subjective OD had low scores on the olfactory test, whereas most patients with subjective TD had normal scores on the taste test.
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COVID-19 , Trastornos del Olfato , Humanos , COVID-19/complicaciones , SARS-CoV-2 , Gusto , Disgeusia , Calidad de Vida , Olfato , Trastornos del Gusto/epidemiología , Trastornos del Gusto/etiología , Trastornos del Olfato/epidemiología , Trastornos del Olfato/etiología , Trastornos del Olfato/diagnósticoRESUMEN
The original version of this article, published on 10 September 2020 contained a mistake.
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Most atypical fractures associated with the long-term treatment with bisphosphonates (BP) commonly develop in the femoral shaft or subtrochanteric region. We report a rare case of bilateral atypical ulnar fractures in an 86-year-old woman with osteoporosis who finished the treatment with teriparatide for 2 years after long-term treatment with BP. She slid down from an approximately 30-cm-tall seat and slightly contused her left elbow. Plain radiography revealed that both ulnae had a noncomminuted short oblique fracture with cortical thickening and sclerosis at the fracture site. Based on the clinical and radiological findings, she was diagnosed with bilateral atypical ulnar fractures. The fracture of the left ulna was completely displaced and treated surgically. On the other hand, since the right ulna was an incomplete fracture, it was treated conservatively. During surgery, drilling with Kirschner wire and curettage were performed in the osteosclerotic lesion, and an autologous cancellous bone graft was inserted from the ipsilateral olecranon. Bone union was achieved in both fractures at 1 year after surgery. There have been no reports regarding the development of atypical ulnar fractures occurring after the long-term treatment with BP and 2-year use of teriparatide, and the treatment strategies of such fractures have not been established. If teriparatide cannot be used after occurring atypical fractures, the use of low-intensity pulsed ultrasound (LIPUS) and subsequent treatment for osteoporosis are recommended for the bone union. In addition, the treatment of the osteosclerotic lesion and rigid internal fixation are required in surgery.
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Conservadores de la Densidad Ósea , Fracturas del Fémur , Teriparatido/efectos adversos , Fracturas del Cúbito , Anciano de 80 o más Años , Conservadores de la Densidad Ósea/efectos adversos , Conservadores de la Densidad Ósea/uso terapéutico , Difosfonatos , Femenino , Humanos , Teriparatido/uso terapéutico , Fracturas del Cúbito/inducido químicamente , Fracturas del Cúbito/diagnóstico por imagen , Fracturas del Cúbito/cirugíaAsunto(s)
Obstrucción de las Vías Aéreas/cirugía , Glotis/cirugía , Laringoestenosis/cirugía , Lupus Eritematoso Sistémico/complicaciones , Mucosa Respiratoria/cirugía , Adherencias Tisulares/cirugía , Adulto , Obstrucción de las Vías Aéreas/etiología , Constricción Patológica/etiología , Constricción Patológica/cirugía , Trastornos de Deglución/etiología , Trastornos de Deglución/cirugía , Femenino , Humanos , Laringoestenosis/etiología , Microcirugia , Recurrencia , Adherencias Tisulares/etiología , TraqueostomíaRESUMEN
Corynebacterium ulcerans (toxigenic C. ulcerans) produces the diphtheria toxin, which causes pharyngeal and cutaneous diphtheria-like disease in people, and this bacterium is commonly detected in dogs and cats that are reared at home. It is considered dangerous when a carrier animal becomes the source of infection in people. To investigate the carrier situation of toxigenic C. ulcerans of cats bred in Japan, bacteria were isolated from 37 cats with a primary complaint of rhinitis in 16 veterinary hospitals in Osaka. Toxigenic C. ulcerans was detected in two of the cats. By drug sensitivity testing, the detected bacterium was sensitive to all investigated drugs, except clindamycin. It appears necessary to create awareness regarding toxigenic C. ulcerans infection in pet owners because this bacterium is believed to be the causative organism for rhinitis in cats.
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Portador Sano/veterinaria , Enfermedades de los Gatos/microbiología , Corynebacterium/aislamiento & purificación , Rinitis/veterinaria , Animales , Antibacterianos/farmacología , Toxinas Bacterianas/genética , Toxinas Bacterianas/farmacología , Portador Sano/microbiología , Gatos , Supervivencia Celular/efectos de los fármacos , Corynebacterium/efectos de los fármacos , Corynebacterium/genética , Japón , Masculino , Pruebas de Sensibilidad Microbiana , Rinitis/microbiología , Células VeroRESUMEN
Phase separation of mixtures composed of a guest polymer dissolved in monomer of a host polymer was induced by photopolymerization. From the polymerization kinetics, it was found that for the host polymer with the glass transition temperature (Tg) higher than the experimental temperature, the Trommsdorff-Norrish effect emerges, providing a method to terminate the phase separation at various intermediate stages of the process and thereby a variety of morphologies can be constructed. For the host polymers with (Tg) lower than the experimental temperature, the freezing process of morphology is not complete, leading to the secondary phase separation inside the domains already generated by the primary process. The kinetics of this secondary phase separation indicates that the peculiar morphology like "sunny-side-up egg"-like structures was generated via spinodal decomposition. The experimental results obtained in this study show that the competition between photopolymerization and phase separation can provide a useful method of materials design in the micro- and sub-micrometer scales.
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BACKGROUND: Interleukin-6 (IL-6) has an important role in cancer progression, and high levels of plasma IL-6 are correlated with a poor prognosis in a variety of cancers. It has also been reported that tumour stromal fibroblasts are necessary for steps in cancer progression, such as angiogenesis. There have been few reports of a correlation between fibroblast actions and IL-6 levels. In this study, we examined the correlation between cancer stromal fibroblasts and IL-6 and the utility of IL-6 as a therapeutic target in human colon cancer. METHODS: The expression levels of IL-6 and VEGF of fibroblasts and cancer cell lines were evaluated using real-time PCR and ELISA. The anti-angiogenic effect of inhibiting IL-6 signalling was measured in an angiogenesis model and animal experiment. RESULTS: We demonstrate that stromal fibroblasts isolated from colon cancer produced significant amounts of IL-6 and that colon cancer cells enhanced IL-6 production by stromal fibroblasts. Moreover, IL-6 enhanced VEGF production by fibroblasts, thereby inducing angiogenesis. In vivo, anti-IL6 receptor antibody targeting stromal tissue showed greater anti-tumour activity than did anti-IL6 receptor antibody targeting xenografted cancer cells. CONCLUSION: Cancer stromal fibroblasts were an important source of IL-6 in colon cancer. IL-6 produced by activated fibroblasts induced tumour angiogenesis by stimulating adjacent stromal fibroblasts. The relationship between IL-6 and stromal fibroblasts offers new approaches to cancer therapy.
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Anticuerpos/farmacología , Neoplasias del Colon/irrigación sanguínea , Neoplasias del Colon/tratamiento farmacológico , Fibroblastos/metabolismo , Interleucina-6/metabolismo , Receptores de Interleucina-6/metabolismo , Células del Estroma/efectos de los fármacos , Animales , Línea Celular , Línea Celular Tumoral , Neoplasias del Colon/metabolismo , Fibroblastos/efectos de los fármacos , Fibroblastos/enzimología , Fibroblastos/patología , Células HT29 , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Inflamación/patología , Ratones , Ratones Desnudos , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , Células del Estroma/metabolismo , Células del Estroma/patología , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
The FIB-4 index is a simple formula to predict liver fibrosis based on the standard biochemical values (AST, ALT and platelet count) and age. We here investigated the utility of the index for noninvasive prediction of progression in liver fibrosis. The time-course alteration in the liver fibrosis stage between paired liver biopsies and the FIB-4 index was examined in 314 patients with chronic hepatitis C. The average interval between liver biopsies was 4.9 years. The cases that showed a time-course improvement in the fibrosis stage exhibited a decrease in the FIB-4 index, and those that showed deterioration in the fibrosis stage exhibited an increase in the FIB-4 index with a significant correlation (P < 0.001). Increase in the ΔFIB-4 index per year was an independent predictive factor for the progression in liver fibrosis with an odds ratio of 3.90 (P = 0.03). The area under the receiver operating characteristic curve of the ΔFIB-4 index/year for the prediction of advancement to cirrhosis was 0.910. Using a cut-off value of the ΔFIB-4 index/year <0.4 or ≥ 0.4, the cumulative incidence of fibrosis progression to cirrhosis at 5 and 10 years was 34% and 59%, respectively in patients with the ΔFIB-4 index/year ≥0.4, whereas it was 0% and 3% in those with the ΔFIB-4 index/year <0.4 (P < 0.001). In conclusion, measurement of the time-course changes in the FIB-4 index is useful for the noninvasive and real-time estimation of the progression in liver fibrosis.
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Alanina Transaminasa/sangre , Aspartato Aminotransferasas/sangre , Hepatitis C Crónica/complicaciones , Cirrosis Hepática/etiología , Adulto , Factores de Edad , Anciano , Biopsia , Estudios de Cohortes , Demografía , Progresión de la Enfermedad , Femenino , Hepatitis C Crónica/metabolismo , Hepatitis C Crónica/virología , Humanos , Incidencia , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/metabolismo , Cirrosis Hepática/virología , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Valor Predictivo de las Pruebas , Índice de Severidad de la Enfermedad , Factores de TiempoRESUMEN
BACKGROUND: Epithelial mesenchymal transition (EMT) is known to be associated with chemoresistance as well as increased invasion/metastasis. However, the relationship between EMT and resistance to an epidermal growth factor receptor (EGFR) -targeting drug in head and neck squamous cell carcinoma (HNSCC) remains unknown. In this study, we investigated the acquisition of EMT by gefitinib in HNSCC cell line (UMSCC81B). METHODS: We isolated fibroblastoid variant (81B-Fb) from gefitinib-resistant UMSCC81B-GR3 cells obtained after increasing the doses of gefitinib treatment in vitro and examined EMT and its underlying mechanism. RESULT: 81B-Fb cells exhibited fibroblast-like morphology, increased motility, loss of E-cadherin, acquisition of vimentin and snail expression. In 81B-Fb cells, downregulation of EGFR, which is mediated by increased ubiquitination, and activation of downstream protein kinase B (Akt), glycogen synthase kinase-beta (GSK-3ß) signalling and upregulation of snail expression were observed compared with UMSCC81B cells. LY294002, but not U0126, suppressed foetal bovine serum or heregulin-ß1-induced phosphorylation of Akt/GSK-3ß and snail expression together with the inhibition of 81B-Fb cell motility. Furthermore, forced expression of EGFR resulted in partial restoration of gefitinib sensitivity and reversal of EMT. CONCLUSION: These results suggest that EMT in the gefitinib-resistant cells is mediated by the downregulation of EGFR and compensatory activation of Akt/GSK-3ß/snail pathway.
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Antineoplásicos/farmacología , Carcinoma/patología , Resistencia a Antineoplásicos , Transición Epitelial-Mesenquimal , Neoplasias de Cabeza y Cuello/patología , Quinazolinas/farmacología , Transducción de Señal , Animales , Carcinoma/metabolismo , Línea Celular Tumoral/efectos de los fármacos , Movimiento Celular , Proliferación Celular , Regulación hacia Abajo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Gefitinib , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Neoplasias de Cabeza y Cuello/metabolismo , Humanos , Masculino , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Fenotipo , Fosforilación , Transporte de Proteínas , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factores de Transcripción de la Familia Snail , Factores de Transcripción/metabolismoRESUMEN
A Ku-band (12-18 GHz) multichannel Doppler reflectometer (DR) has been developed in the GAMMA 10/potential control and divertor simulating experiment (PDX) tandem mirror device to improve the applicability of DR measurement for simultaneous monitoring of velocity of electron density turbulence at different locations. Our previous single-channel DR circuit has been replaced by the multichannel microwave system using a nonlinear transmission line based comb generator with heterodyne technique. The multichannel DR system has been installed in the central cell of GAMMA 10/PDX. Initial results of application to GAMMA 10/PDX plasma are presented, showing Doppler frequency shifts during an additional ion cyclotron resonance frequency heating and gas-puffing experiment.
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In high-frequency pulsed magnets, such as kickers in particle accelerators, it is essential to reduce eddy currents that could be induced in the magnet core during excitation not to distort and attenuate the magnetic field pulse. A novel iron lamination scheme with additional interlaminar insulation is proposed for the magnet core of such pulsed magnets. A laminated steel sheet core is formed by alternately stacking thin steel and insulation sheets. For application to matched kicker magnets for accelerators, test magnets with the new and conventional iron lamination were designed, assembled, and extensively evaluated. The pulsed magnetic field waveforms of two test magnets with the new lamination successfully matched to below 0.1% over the entire pulse duration, which was significantly better than those with the conventional lamination. Among the applications of the developed high-frequency pulsed magnets, beam injection kickers for the coming next generation light sources and future colliders, where suppression of the transient stored-beam oscillation during beam injection is crucial, are considered to be promising.
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The multipass Thomson scattering (MPTS) technique is one of the most useful methods for measuring low-electron-density plasmas. The MPTS system increases Thomson scattering (TS) signal intensities by integrating all multipass (MP) signals and improving the TS time resolution by analyzing each pass signal. The fully coaxial MPTS system developed in GAMMA 10/potential-control and diverter-simulator experiments has a polarization-based configuration with image-relaying optics. The MPTS system can enhance Thomson scattered signals for improving the measurement accuracy and megahertz-order time resolution. In this study, we develop a new MPTS system comprising a laser amplification system to obtain continuous MP signals. The laser amplification system can improve degraded laser power and return an amplified laser to the MP system. We obtain continuous MP signals from the laser amplification system by improving the laser beam profile adjuster in gas scattering experiments. Moreover, we demonstrate that more MP signals and stronger amplified MP signals can be achieved via multiple laser injections to the laser amplification system in the developed MP system comprising a laser amplification system.
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Shigella, the causative agent of bacillary dysentery, is capable of directing its movement within host cells by exploiting actin dynamics. The VirG protein expressed at one pole of the bacterium can recruit neural Wiskott-Aldrich syndrome protein (N-WASP), a downstream effector of Cdc42. Here, we show that Cdc42 is required for the actin-based motility of Shigella. Microinjection of a dominant active mutant Cdc42, but not Rac1 or RhoA, into Swiss 3T3 cells accelerated Shigella motility. In add-back experiments in Xenopus egg extracts, addition of a guanine nucleotide dissociation inhibitor for the Rho family, RhoGDI, greatly diminished the bacterial motility or actin assembly, which was restored by adding activated Cdc42. In N-WASP-depleted extracts, the bacterial movement almost arrested was restored by adding exogenous N-WASP but not H208D, an N-WASP mutant defective in binding to Cdc42. In pyrene actin assay, Cdc42 enhanced VirG-stimulating actin polymerization by N-WASP-actin-related protein (Arp)2/3 complex. Actually, Cdc42 stimulated actin cloud formation on the surface of bacteria expressing VirG in a solution containing N-WASP, Arp2/3 complex, and G-actin. Immunohistological study of Shigella-infected cells expressing green fluorescent protein-tagged Cdc42 revealed that Cdc42 accumulated by being colocalized with actin cloud at one pole of intracellular bacterium. Furthermore, overexpression of H208D mutant in cells interfered with the actin assembly of infected Shigella and diminished the intra- and intercellular spreading. These results suggest that Cdc42 activity is involved in initiating actin nucleation mediated by VirG-N-WASP-Arp2/3 complex formed on intracellular Shigella.
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Actinas/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Shigella flexneri/fisiología , Proteína de Unión al GTP cdc42/metabolismo , Células 3T3 , Animales , Proteínas Bacterianas/metabolismo , Células COS , Proteínas de Unión al ADN/metabolismo , Perros , Inhibidores de Disociación de Guanina Nucleótido , Humanos , Mamíferos , Ratones , Microinyecciones/métodos , Proteínas del Tejido Nervioso/genética , Óvulo/metabolismo , Conejos , Ratas , Factores de Transcripción/metabolismo , Proteína Neuronal del Síndrome de Wiskott-Aldrich , Xenopus/metabolismo , Inhibidor alfa de Disociación del Nucleótido Guanina rho , Inhibidores de la Disociación del Nucleótido Guanina rho-EspecíficoRESUMEN
Only a few cases of various glomerulonephropathies have been reported in patients with polycythemia vera. We report the case of a 72-year-old female with polycythemia vera in whom renal biopsy examination showed membranoproliferative glomerulonephritis (MPGN)-like lesion and glomerular expression of plasmalemmal vesicle-associated protein-1 (PV-1), a marker of glomerular capillary remodeling after injury. Prior to admission to our hospital for nephrotic syndrome, she had received hydroxyurea and phlebotomy. On admission, she was hypertensive with pretibial edema, hepatosplenomegaly, massive proteinuria (6.14 g/day), low serum albumin (2.9 g/dl), high fibrinogen, fibrin/fibrinogen degradation products and thrombomodulin levels, but with normal serum creatinine and complement levels. Microscopic examination of a renal biopsy demonstrated MPGN-like features with double contour and mesangial interposition. Electron microscopy showed subendothelial deposits, platelets attached to glomerular capillary walls and fibrin deposition. Immunofluorescence study identified IgM deposition along part of the capillary wall and mesangium. CD42b-positive platelets and megakaryocytes were detected in glomerular capillaries, accompanied with increased expression of platelet-derived growth factor receptor b and thrombomodulin in the mesangium and glomerular capillary, respectively. PV-1 was expressed along the glomerular capillary. Anti-platelet and anticoagulant combination therapy, together with the use of anti-hypertensive agents and hydroxyurea, resulted in improvement of the nephrotic syndrome. The findings suggested that activated platelets, enhanced coagulation state and endothelial damage may contribute to glomerulonephropathy associated with polycythemia vera.
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Proteínas Portadoras/análisis , Glomerulonefritis Membranoproliferativa/etiología , Glomérulos Renales/patología , Proteínas de la Membrana/análisis , Policitemia Vera/complicaciones , Anciano , Anticoagulantes/uso terapéutico , Antihipertensivos/uso terapéutico , Biopsia , Quimioterapia Combinada , Femenino , Técnica del Anticuerpo Fluorescente , Glomerulonefritis Membranoproliferativa/tratamiento farmacológico , Glomerulonefritis Membranoproliferativa/metabolismo , Glomerulonefritis Membranoproliferativa/patología , Humanos , Hidroxiurea/uso terapéutico , Glomérulos Renales/efectos de los fármacos , Glomérulos Renales/metabolismo , Microscopía Electrónica , Síndrome Nefrótico/etiología , Síndrome Nefrótico/metabolismo , Síndrome Nefrótico/patología , Inhibidores de Agregación Plaquetaria/uso terapéutico , Policitemia Vera/tratamiento farmacológico , Policitemia Vera/metabolismo , Policitemia Vera/patología , Resultado del TratamientoRESUMEN
Recent studies have showed that the bone marrow-derived endothelial progenitor cells play critical roles in metastasis and that ID1 is required in metastasis as regulator of angiogenesis. Therefore, we investigated the clinical significance of ID1 mRNA expression in bone marrow and peripheral samples in patients with gastric cancer. Two hundred and eighty-nine bone marrow and 196 peripheral blood samples from gastric cancer patients were collected and analysed by quantitative RT-PCR for ID1. The ID1 protein expression in one bone marrow, three metastatic lymph nodes and three peritoneal disseminated tumours was examined by immunohistochemical methods. In both bone marrow and peripheral blood samples, ID1 mRNA expression in the metastatic group was significantly higher than in any other group (P=0.003, P=0.0001, respectively) and significantly associated with lymph node metastasis and peritoneal dissemination. The cells in bone marrow with metastatic cancer stained strongly with ID1 compared with those of healthy volunteers. The expression of ID1 mRNA in bone marrow and peripheral blood was significantly associated with lymph node metastasis and peritoneal dissemination, and therefore constitutes a predictable marker for lymph node metastasis and peritoneal dissemination.
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Biomarcadores de Tumor/genética , Médula Ósea/metabolismo , Proteína 1 Inhibidora de la Diferenciación/sangre , Proteína 1 Inhibidora de la Diferenciación/genética , Neoplasias Peritoneales/genética , Neoplasias Gástricas/genética , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Técnicas para Inmunoenzimas , Metástasis Linfática , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Neoplasias Peritoneales/metabolismo , Neoplasias Peritoneales/secundario , Pronóstico , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias Gástricas/sangre , Neoplasias Gástricas/patología , Adulto JovenRESUMEN
Usher syndrome (USH) is an autosomal recessive disorder characterized by retinitis pigmentosa and hearing loss. USH type 2 (USH2) is the most common type of USH and is frequently caused by mutations in USH2A, which accounts for 74-90% of USH2 cases. This is the first study reporting the results of scanning for USH2A mutations in Japanese patients with USH2. In 8 of 10 unrelated patients, we identified 14 different mutations. Of these mutations, 11 were novel. Although the mutation spectrum that we identified differed from that for Caucasians, the incidence of mutations in USH2A was 80% for all patients tested, which is consistent with previous findings. Further, c.8559-2A>G was identified in four patients and accounted for 26.7% of mutated alleles; it is thus a frequent mutation in Japanese patients. Hence, mutation screening for c.8559-2A>G in USH2A may prove very effective for the early diagnosis of USH2.
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Proteínas de la Matriz Extracelular/genética , Predisposición Genética a la Enfermedad/genética , Mutación/genética , Síndromes de Usher/genética , Adulto , Pueblo Asiatico , Análisis Mutacional de ADN , Cartilla de ADN/genética , Femenino , Pruebas Genéticas , Humanos , Japón , Masculino , Persona de Mediana EdadRESUMEN
We isolated two novel actin filament (F-actin)-binding proteins from rat brain and rat 3Y1 fibroblast. They were splicing variants, and we named brain big one b-nexilin and fibroblast small one s-nexilin. b-Nexilin purified from rat brain was a protein of 656 amino acids (aa) with a calculated molecular weight of 78,392, whereas s-nexilin, encoded by the cDNA isolated from rat 3Y1 cells by the reverse transcriptase-PCR method, was a protein of 606 aa with a calculated molecular weight of 71,942. b-Nexilin had two F-actin- binding domains (ABDs) at the NH2-terminal and middle regions, whereas s-nexilin had one ABD at the middle region because 64 aa residues were deleted and 14 aa residues were inserted in the first NH2-terminal ABD of b-nexilin, and thereby the first ABD lost its activity. b- and s-nexilins bound along the sides of F-actin, but only b-nexilin showed F-actin cross-linking activity. b-Nexilin was mainly expressed in brain and testis, whereas s-nexilin was mainly expressed in testis, spleen, and fibroblasts, such as rat 3Y1 and mouse Swiss 3T3 cells, but neither b- nor s-nexilin was detected in liver, kidney, or cultured epithelial cells. An immunofluorescence microscopic study revealed that s-nexilin was colocalized with vinculin, talin, and paxillin at cell- matrix adherens junction (AJ) and focal contacts, but not at cell-cell AJ, in 3Y1 cells. Overexpressed b- and s-nexilins were localized at focal contacts but not at cell-cell AJ. These results indicate that nexilin is a novel F-actin-binding protein localized at cell-matrix AJ.
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Actinas/metabolismo , Proteínas Portadoras/metabolismo , Proteínas de Microfilamentos/metabolismo , Empalme Alternativo , Secuencia de Aminoácidos , Animales , Encéfalo/metabolismo , Proteínas Portadoras/química , Proteínas Portadoras/genética , Adhesión Celular , Línea Celular , Clonación Molecular , ADN Complementario/genética , Matriz Extracelular/metabolismo , Inmunohistoquímica , Uniones Intercelulares/metabolismo , Masculino , Ratones , Proteínas de Microfilamentos/química , Proteínas de Microfilamentos/genética , Datos de Secuencia Molecular , Peso Molecular , Ratas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , Distribución TisularRESUMEN
We purified from rat brain a novel actin filament (F-actin)-binding protein of approximately 180 kD (p180), which was specifically expressed in neural tissue. We named p180 neurabin (neural tissue-specific F-actin- binding protein). We moreover cloned the cDNA of neurabin from a rat brain cDNA library and characterized native and recombinant proteins. Neurabin was a protein of 1,095 amino acids with a calculated molecular mass of 122,729. Neurabin had one F-actin-binding domain at the NH2-terminal region, one PSD-95, DlgA, ZO-1-like domain at the middle region, a domain known to interact with transmembrane proteins, and domains predicted to form coiled-coil structures at the COOH-terminal region. Neurabin bound along the sides of F-actin and showed F-actin-cross-linking activity. Immunofluorescence microscopic analysis revealed that neurabin was highly concentrated in the synapse of the developed neurons. Neurabin was also concentrated in the lamellipodia of the growth cone during the development of neurons. Moreover, a study on suppression of endogenous neurabin in primary cultured rat hippocampal neurons by treatment with an antisense oligonucleotide showed that neurabin was involved in the neurite formation. Neurabin is a candidate for key molecules in the synapse formation and function.
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Actinas/metabolismo , Proteínas de Microfilamentos/fisiología , Proteínas del Tejido Nervioso/fisiología , Neuritas/ultraestructura , Secuencia de Aminoácidos , Animales , Células Cultivadas , Clonación Molecular , ADN Complementario/genética , Hipocampo/metabolismo , Datos de Secuencia Molecular , Oligonucleótidos Antisentido , Ratas , Distribución TisularRESUMEN
We have found a new cell-cell adhesion system at cadherin-based cell-cell adherens junctions (AJs) consisting of at least nectin and l-afadin. Nectin is a Ca(2+)-independent homophilic immunoglobulin-like adhesion molecule, and l-afadin is an actin filament-binding protein that connects the cytoplasmic region of nectin to the actin cytoskeleton. Both the trans-interaction of nectin and the interaction of nectin with l-afadin are necessary for their colocalization with E-cadherin and catenins at AJs. Here, we examined the mechanism of interaction between these two cell-cell adhesion systems at AJs by the use of alpha-catenin-deficient F9 cell lines and cadherin-deficient L cell lines stably expressing their various components. We showed here that nectin and E-cadherin were colocalized through l-afadin and the COOH-terminal half of alpha-catenin at AJs. Nectin trans-interacted independently of E-cadherin, and the complex of E-cadherin and alpha- and beta-catenins was recruited to nectin-based cell-cell adhesion sites through l-afadin without the trans-interaction of E-cadherin. Our results indicate that nectin and cadherin interact through their cytoplasmic domain-associated proteins and suggest that these two cell-cell adhesion systems cooperatively organize cell-cell AJs.