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1.
Int Endod J ; 52(5): 639-645, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30447154

RESUMEN

AIM: To investigate the proliferation and mineralization of a human cementoblast cell line under alkaline conditions. METHODOLOGY: A human cementoblast cell line was cultured in alkaline media with several pHs (pH 7.6, 8.0 and 8.4) without CO2 . Cell numbers, phospho-p44/42 expression, alkaline phosphatase (ALP) activity and mineralization were evaluated. The significance of differences between groups was assessed using two-way analysis of variance 15 (ANOVA) followed by Bonferroni's multiple comparison test (α = 0.01). RESULTS: Cell numbers increased in a time-dependent manner in the high pH medium groups. Western blot analysis revealed the upregulated expression of phospho-p44/42 under alkaline conditions. ALP activity was also increased at pH 8.0 and 8.4. Alizarin red staining revealed increased mineralization in the high pH medium groups. The incorporation of the transient receptor potential ankyrin subfamily member 1 (TRPA1) antagonist HC030031 markedly negated the effect on proliferation and mineralization. CONCLUSIONS: Extracellular alkaline conditions promoted the proliferation and mineralization of human cementoblasts in vitro via TRPA1.


Asunto(s)
Fosfatasa Alcalina , Cemento Dental , Calcificación Fisiológica , Recuento de Células , Diferenciación Celular , Línea Celular , Proliferación Celular , Células Cultivadas , Humanos
2.
Climacteric ; 20(6): 571-576, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28933961

RESUMEN

OBJECTIVE: The aim of this report was to evaluate the impact of hormone replacement therapy (HRT) on lymphocytic infiltration of the endometrium in postmenopausal women. METHOD: This study included 58 Japanese patients who had undergone hysterectomy at the University Hospital of Occupational and Environmental Health, Japan. Before surgery, nine patients had received 17ß-estradiol (E2), 0.72 mg transdermally for 2-8 weeks (E2 group); 16 patients had received an Estra-1,3,5(10)-triene-3,16α, 17ß-triol (E3) vaginal tablet 0.5 mg per month five times (E3 group); and 19 patients had received 17ß-estradiol, 0.62 mg, and norethindrone acetate (P), 2.70 mg for 3-16 weeks (E2 + P group). Fourteen patients received no HRT (control group). We examined uterine tissue specimens immunohistochemically for CD45+, CD3+, CD4+, CD8+, CD20+, CD56+, and Ki67 antigen-positive cells. RESULTS: The numbers of CD56 + cells were significantly increased in the E2 group compared with all other groups (E2 vs. E3: 7.0 vs. 0.75, p = 0.017; E2 vs. E2 + P: 7.0 vs. 0.58, p = 0.009; E2 vs. CONTROL: 7.0 vs. 0.43, p = 0.010). The numbers of CD3+ cells were significantly increased in the E2 group compared with the control group (149.3 vs. 42.6, p = 0.008). CONCLUSION: 17ß-Estradiol induced the proliferation of endometrial uterine natural killer cells (CD56+) in postmenopausal women.


Asunto(s)
Endometrio/efectos de los fármacos , Estradiol/farmacología , Terapia de Reemplazo de Estrógeno , Células Asesinas Naturales/efectos de los fármacos , Posmenopausia , Administración Cutánea , Proliferación Celular/efectos de los fármacos , Endometrio/citología , Estradiol/administración & dosificación , Femenino , Humanos , Células Asesinas Naturales/citología , Persona de Mediana Edad
3.
Opt Express ; 22(1): 1143-51, 2014 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-24515074

RESUMEN

We experimentally study the spectral broadening of intense, ∼ 100 femtosecond laser pulses at 785 nm coupled into different kinds of hollow core capillary fibers, all filled with air at ambient pressure. Differently from observations in other gases, the spectra are broadened with a strong red-shift due to highly efficient intrapulse Raman scattering. Numerical simulations show that such spectra can be explained only by increasing the Raman fraction of the third order nonlinearity close to 100%. Experimentally, these broadened and red-shifted pulses do not generally allow for straightforward compression using, for example, standard chirped mirrors. However, using special hollow fibers that are internally coated with silver and polymer we obtain pulse durations in the sub-20 fs regime with energies up to 300 µJ.

4.
Eur J Gynaecol Oncol ; 35(2): 163-6, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24772920

RESUMEN

PURPOSE: To review the treatment of primary retroperitoneal mucinous cystadenocarcinoma (PRMC). CASE REPORT: A 30-year-old woman had a large retroperitoneal mucinous adenocarcinoma treated with conservative laparoscopic surgery. Two years later, she was found to have bilateral ovarian cysts at the time of cesarean section. Since cystectomies revealed mucinous adenocarcinoma, she underwent complete surgical staging and adjuvant chemotherapy at this time. CONCLUSION: A rare case of similar cancer in the ovary following treatment for PRMC was described. It is unclear whether the prognosis is improved by oophorectomy. Further cases and long-term follow-up are necessary.


Asunto(s)
Adenocarcinoma Mucinoso/cirugía , Cistadenocarcinoma Mucinoso/cirugía , Neoplasias Primarias Secundarias/cirugía , Neoplasias Ováricas/cirugía , Neoplasias Retroperitoneales/cirugía , Adenocarcinoma Mucinoso/patología , Adulto , Cistadenocarcinoma Mucinoso/patología , Femenino , Humanos , Neoplasias Primarias Secundarias/patología , Neoplasias Ováricas/patología , Ovariectomía , Neoplasias Retroperitoneales/patología
5.
Vet Pathol ; 49(5): 819-23, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22081134

RESUMEN

The origin and transmission routes of atypical bovine spongiform encephalopathy (BSE) remain unclear. To assess whether the biological and biochemical characteristics of atypical L-type BSE detected in Japanese cattle (BSE/JP24) are conserved during serial passages within a single host, 3 calves were inoculated intracerebrally with a brain homogenate prepared from first-passaged BSE/JP24-affected cattle. Detailed immunohistochemical and neuropathologic analysis of the brains of second-passaged animals, which had developed the disease and survived for an average of 16 months after inoculation, revealed distribution of spongiform changes and disease-associated prion protein (PrP(Sc)) throughout the brain. Although immunolabeled PrP(Sc) obtained from brain tissue was characterized by the presence of PrP plaques and diffuse synaptic granular accumulations, no stellate-type deposits were detected. Western blot analysis suggested no obvious differences in PrP(Sc) molecular mass or glycoform pattern in the brains of first- and second-passaged cattle. These findings suggest failures to identify differences in mean incubation period and biochemical and neuropathologic properties of the BSE/JP24 prion between the first and second passages in cattle.


Asunto(s)
Encéfalo/patología , Encefalopatía Espongiforme Bovina/transmisión , Proteínas PrPSc/metabolismo , Animales , Western Blotting/veterinaria , Encéfalo/metabolismo , Bovinos , Encefalopatía Espongiforme Bovina/metabolismo , Encefalopatía Espongiforme Bovina/patología , Femenino , Glicosilación , Inmunohistoquímica/veterinaria , Proteínas PrPSc/análisis , Conformación Proteica , Estabilidad Proteica , Pase Seriado
6.
Am J Transplant ; 11(6): 1325-9, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21645259

RESUMEN

IL28B genetic polymorphism is related to interferon-sensitivity in chronic hepatitis C, but the significance of grafts carrying different genotypes from recipients is still unclear in liver transplantation. A 51-year-old Japanese male carrying a minor genotype underwent dual liver transplantation for liver cirrhosis due to hepatitis C virus (HCV). The left lobe graft carried a major genotype, and the right a minor genotype. He achieved virological response during the course of pegylated-interferon and ribavirin therapy against recurrent hepatitis C for 2 years, but HCV relapsed immediately at the end of the therapy. Two years after antiviral therapy, liver biopsy was performed from each graft. The specimens showed A1F0 in the left lobe graft and A2F2 in the right. Moreover, quantitative polymerase chain reaction was performed using RNA extracted from each specimen to see there was no HCV RNA in the left lobe whereas there was in the right. This case provides clear evidence that IL28B genetic variants determine interferon sensitivity in recurrent hepatitis C following liver transplantation, which could result in new strategies for donor selection or for posttransplant antiviral therapy to HCV positive recipients.


Asunto(s)
Variación Genética , Hepatitis C/genética , Interleucinas/genética , Trasplante de Hígado/efectos adversos , Secuencia de Bases , Cartilla de ADN , Humanos , Interferones , Masculino , Persona de Mediana Edad , Recurrencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
7.
Nat Cell Biol ; 2(11): 805-11, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11056535

RESUMEN

Although cAMP is well known to regulate exocytosis in many secretory cells, its direct target in the exocytotic machinery is not known. Here we show that cAMP-GEFII, a cAMP sensor, binds to Rim (Rab3-interacting molecule, Rab3 being a small G protein) and to a new isoform, Rim2, both of which are putative regulators of fusion of vesicles to the plasma membrane. We also show that cAMP-GEFII, through its interaction with Rim2, mediates cAMP-induced, Ca2+-dependent secretion that is not blocked by an inhibitor of cAMP-dependent protein kinase (PKA). Accordingly, cAMP-GEFII is a direct target of cAMP in regulated exocytosis and is responsible for cAMP-dependent, PKA-independent exocytosis.


Asunto(s)
Proteína Receptora de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Exocitosis/fisiología , Proteínas de Unión al GTP , Proteínas del Tejido Nervioso/metabolismo , Animales , Secuencia de Bases , Células COS , Proteínas Portadoras , Chlorocebus aethiops , Proteína Receptora de AMP Cíclico/genética , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , ADN Complementario , Ratones , Datos de Secuencia Molecular , Proteínas del Tejido Nervioso/genética , Ratas
8.
Nat Med ; 1(3): 249-55, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7585042

RESUMEN

Telomerase activity was analysed in 100 neuroblastoma cases. Although telomerase activity was not detected in normal adrenal tissues or benign ganglioneuromas, almost all neuroblastomas (94%) did express it, suggesting an important role for telomerase in neuroblastoma development. Neuroblastomas with high telomerase activity had other genetic changes (for example, N-myc amplification) and an unfavourable prognosis, whereas tumours with low telomerase activity were devoid of such genetic alterations and were associated with a favourable prognosis. Three neuroblastomas lacking telomerase activity regressed (stage IVS). Thus telomerase expression may be required as a critical step in the multigenetic process of tumorigenesis, and two different pathways may exist for the development of neuroblastoma.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/enzimología , Neuroblastoma/enzimología , Telomerasa/metabolismo , Telómero/ultraestructura , Neoplasias de las Glándulas Suprarrenales/ultraestructura , Glándulas Suprarrenales/embriología , Glándulas Suprarrenales/enzimología , Secuencia de Bases , Niño , Cartilla de ADN/química , Ganglioneuroma/enzimología , Humanos , Lactante , Masculino , Datos de Secuencia Molecular , Neuroblastoma/ultraestructura , Pronóstico
9.
Nat Med ; 4(9): 1065-7, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9734402

RESUMEN

Hepatitis C virus (HCV) is the main cause of chronic hepatitis worldwide. Chronic hepatitis ultimately results in the development of hepatocellular carcinoma (HCC). However, the mechanism of hepatocarcinogenesis in chronic HCV infection is still unclear. The ability of the core protein of HCV to modulate gene transcription, cell proliferation and cell death may be involved in the pathogenesis of HCC. Here, we report the development of HCC in two independent lines of mice transgenic for the HCV core gene, which develop hepatic steatosis early in life as a histological feature characteristic of chronic hepatitis C. After the age of 16 months, mice of both lines developed hepatic tumors that first appeared as adenomas containing fat droplets in the cytoplasm. Then HCC, a more poorly-differentiated neoplasia, developed from within the adenomas, presenting in a 'nodule-in-nodule' manner without cytoplasmic fat droplets; this closely resembled the histopathological characteristics of the early stage of HCC in patients with chronic hepatitis C. These results indicate that the HCV core protein has a chief role in the development of HCC, and that these transgenic mice provide good animal models for determining the molecular events in hepatocarcinogenesis with HCV infection.


Asunto(s)
Carcinoma Hepatocelular/virología , Hepacivirus/fisiología , Neoplasias Hepáticas/virología , Proteínas del Núcleo Viral/fisiología , Animales , Carcinoma Hepatocelular/patología , Transformación Celular Viral , Femenino , Hepatitis C Crónica/metabolismo , Humanos , Neoplasias Hepáticas/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteínas del Núcleo Viral/genética
10.
J Phys Chem A ; 115(28): 8055-63, 2011 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-21671684

RESUMEN

The oriented CO (a (3)Π, v' = 0, Ω = 1 and 2) beam has been prepared by using an electric hexapole and applied to the energy transfer reaction of CO (a (3)Π, v' = 0, Ω = 1 and 2) + NO (X (2)Π) → NO (A (2)Σ(+), B (2)Π) + CO (X (1)Σ(+)). The emission spectra of NO (A (2)Σ(+), B(2)Π) have been measured at three orientation configurations (C-end, O-end, random). The shape of the emission spectra (and/or the internal excitation of products) turns out to be insensitive to the molecular orientation. The vibrational distributions of NO (A (2)Σ(+), v' = 0-2) and NO (B (2)Π, v' = 0-2) are determined to be N(v'=0):N(v'=1):N(v'=2) = 1:0.40 ± 0.05:0.10 ± 0.05 and N(v'=0):N(v'=1):N(v'= 2) = 1:0.6 ± 0.1:0.7 ± 0.1, respectively, and the branching ratio γ/ß [=NO (A (2)Σ(+))/NO (B (2)Π)] is estimated to be γ/ß âˆ¼ 0.3 ± 0.1 by means of spectral simulation. These vibrational distributions of NO (A, B) can be essentially attributed to the product-pair correlations between CO (X, v″) and NO (A (2)Σ(+), v' = 0-2), NO (B (2)Π, v' = 0-2) due to energetic restriction under the vibrational distribution of CO (X, v″) produced from the vertical transition of CO (a (3)Π, v' = 0) → CO (X, v″) in the course of energy transfer. The steric opacity function has been determined at two wavelength regions: 220 < λ < 290 nm [NO (A → X) is dominant]; 320 < λ < 400 nm [NO (B → X) is dominant]. For both channels NO (A (2)Σ(+), B(2)Π), a significant CO (a (3)Π) alignment effect is recognized; the largest reactivity at the sideways direction with the small reactivity at the molecular axis direction is observed. These CO (a (3)Π) alignment effects can be essentially attributed to the steric asymmetry on two sets of molecular orbital overlap, [CO (2π) + NO (6σ (2π))] and [CO (5σ) + NO (1π (2π))]. All experimental observations support the electron exchange mechanism that is operative through the formation of a weakly bound complex OCNO.


Asunto(s)
Monóxido de Carbono/química , Química Física , Transferencia de Energía , Óxido Nítrico/química , Electrones , Isomerismo , Termodinámica , Vibración
11.
J Phys Chem A ; 115(40): 10888-93, 2011 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-21905731

RESUMEN

The atomic alignment effect has been studied for the dissociative energy transfer reaction of metal carbonyls (Fe(CO)(5), Ni(CO)(4)) with the oriented Ar ((3)P(2), M(J) = 2). The emission intensity from the excited metal products (Fe*, Ni*) has been measured as a function of the atomic alignment in the collision frame. The selectivity of the atomic orbital alignment of Ar ((3)P(2), M(J) = 2) (rank 2 moment, a(2)) is found to be opposite for the two reaction systems; the Fe(CO)(5) reaction is favorable at the Π configuration (positive a(2)), while the Ni(CO)(4) reaction is favorable at the Σ configuration (negative a(2)). Moreover, a significant spin alignment effect (rank 4 moment, a(4)) is recognized only in the Ni(CO)(4) reaction. The atomic alignment effect turns out to be essentially different between the two reaction systems; the Fe(CO)(5) reaction is controlled by the configuration of the half-filled 3p atomic orbital of Ar ((3)P(2)) in the collision frame (L dependence), whereas the Ni(CO)(4) reaction is controlled by the configuration of the total angular moment J (including spin) of Ar ((3)P(2)) in the collision frame (J dependence). As the origin of J dependence observed only in the Ni(CO)(4) reaction, the correlation (and/or the interference) between two electron exchange processes via the electron rearrangements is proposed.


Asunto(s)
Argón/química , Compuestos de Hierro Carbonilo/química , Níquel/química , Transferencia de Energía
12.
J Phys Chem A ; 115(18): 4583-91, 2011 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-21491885

RESUMEN

We have studied how the KrF* formation in the NF3 þ Kr*(3P2) reaction depends on the mutual configuration between the orientation of the NF3 molecule and the alignment of the Kr*(3P2, M(J) = 2) atom in the collision frame. The molecular steric opacity function has been determined as a function of the atomic orbital alignment (M'(L)) in the collision frame. The molecular steric opacity function turns out to depend remarkably on M'(L) ; the |M'(L)| = 1 alignment is favorable at the molecular axis direction, whereas the M'(L) = 0 alignment is favorable at the sideways direction with a very poor reactivity at the molecular axis direction. The influence of deformation of the NF3 geometry on the electron affinity has been evaluated by ab initio calculation, and the M'(L) dependent intermolecular potential has been estimated from the interaction potential for the bromine-rare gas system. We propose the "collision-induced harpooning mechanism" as a novel process for the harpooning in which collisional deformation of the NF3 geometry with C(s) symmetry plays an important role as an initiating factor on electron transfer for the formation of NF3(-) due to increasing the electron affinity of NF3 and due to localizing the negative charge on the closest F-atom of NF3(-) anion. All experimental observations can support the collision-induced harpooning mechanism.

13.
Vet Pathol ; 48(5): 942-7, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20921323

RESUMEN

To characterize the biological and biochemical properties of H-type bovine spongiform encephalopathy (BSE), a transmission study with a Canadian H-type isolate was performed with bovinized transgenic mice (TgBoPrP), which were inoculated intracerebrally with brain homogenate from cattle with H-type BSE. All mice exhibited characteristic neurologic signs, and the subsequent passage showed a shortened incubation period. The distribution of disease-associated prion protein (PrP(Sc)) was determined by immunohistochemistry, Western blot, and paraffin-embedded tissue (PET) blot. Biochemical properties and higher molecular weight of the glycoform pattern were well conserved within mice. Immunolabeled granular PrP(Sc), aggregates, and/or plaque-like deposits were mainly detected in the following brain locations: septal nuclei, subcallosal regions, hypothalamus, paraventricular nucleus of the thalamus, interstitial nucleus of the stria terminalis, and the reticular formation of the midbrain. Weak reactivity was detected by immunohistochemistry and PET blot in the cerebral cortex, most thalamic nuclei, the hippocampus, medulla oblongata, and cerebellum. These findings indicate that the H-type BSE prion has biological and biochemical properties distinct from those of C-type and L-type BSE in TgBoPrP mice, which suggests that TgBoPrP mice constitute a useful animal model to distinguish isolates from BSE-infected cattle.


Asunto(s)
Encefalopatía Espongiforme Bovina/transmisión , Proteínas PrPSc/metabolismo , Animales , Western Blotting/veterinaria , Canadá , Bovinos , Encefalopatía Espongiforme Bovina/metabolismo , Encefalopatía Espongiforme Bovina/patología , Femenino , Inmunohistoquímica/veterinaria , Ratones , Ratones Transgénicos , Modelos Animales , Peso Molecular , Adhesión en Parafina/veterinaria , Proteínas PrPSc/análisis
14.
J Cell Biol ; 141(2): 409-18, 1998 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-9548719

RESUMEN

The small GTPase Rho is believed to regulate the actin cytoskeleton and cell adhesion through its specific targets. We previously identified the Rho targets: protein kinase N, Rho-associated kinase (Rho-kinase), and the myosin-binding subunit (MBS) of myosin phosphatase. We found that in MDCK epithelial cells, MBS accumulated at the tetradecanoylphorbol-13-acetate (TPA)-induced membrane ruffling area, where moesin, a member of the ERM (ezrin, radixin, and moesin) family, was localized. Neither membrane ruffling nor an accumulation of moesin and MBS at the free-end plasma membrane was induced when MDCK cells were stimulated with TPA after the microinjection of C3, which ADP-ribosylates and inactivates Rho. MBS was colocalized with moesin at the cell-cell contact sites in MDCK cells. We also found that moesin was coimmunoprecipitated with MBS from MDCK cells. Recombinant MBS interacted with the amino-terminal domains of moesin and ezrin. Myosin phosphatase composed of the catalytic subunit and MBS showed phosphatase activity toward moesin, which was phosphorylated by Rho-kinase. The phosphatase activity was inhibited when MBS was phosphorylated by Rho-kinase. These results suggest that MBS is recruited with moesin to the plasma membrane and that myosin phosphatase and Rho-kinase regulate the phosphorylation state of moesin downstream of Rho.


Asunto(s)
Toxinas Botulínicas , Proteínas de Microfilamentos , Fosfoproteínas Fosfatasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas/metabolismo , ADP Ribosa Transferasas/genética , ADP Ribosa Transferasas/fisiología , Animales , Encéfalo/metabolismo , Bovinos , Línea Celular , Membrana Celular/química , Membrana Celular/enzimología , Membrana Celular/ultraestructura , Sistema Libre de Células , Proteínas del Citoesqueleto , Perros , Células Epiteliales , Péptidos y Proteínas de Señalización Intracelular , Fosfatasa de Miosina de Cadena Ligera , Miosinas/metabolismo , Fosfoproteínas Fosfatasas/análisis , Fosfoproteínas Fosfatasas/genética , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fosforilación , Proteínas/análisis , Proteínas/genética , Proteínas Recombinantes de Fusión , Transducción de Señal/fisiología , Acetato de Tetradecanoilforbol/farmacología , Quinasas Asociadas a rho
15.
J Cell Biol ; 139(3): 785-95, 1997 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-9348294

RESUMEN

The dynamic rearrangement of cell-cell junctions such as tight junctions and adherens junctions is a critical step in various cellular processes, including establishment of epithelial cell polarity and developmental patterning. Tight junctions are mediated by molecules such as occludin and its associated ZO-1 and ZO-2, and adherens junctions are mediated by adhesion molecules such as cadherin and its associated catenins. The transformation of epithelial cells by activated Ras results in the perturbation of cell-cell contacts. We previously identified the ALL-1 fusion partner from chromosome 6 (AF-6) as a Ras target. AF-6 has the PDZ domain, which is thought to localize AF-6 at the specialized sites of plasma membranes such as cell-cell contact sites. We investigated roles of Ras and AF-6 in the regulation of cell-cell contacts and found that AF-6 accumulated at the cell-cell contact sites of polarized MDCKII epithelial cells and had a distribution similar to that of ZO-1 but somewhat different from those of catenins. Immunoelectron microscopy revealed a close association between AF-6 and ZO-1 at the tight junctions of MDCKII cells. Native and recombinant AF-6 interacted with ZO-1 in vitro. ZO-1 interacted with the Ras-binding domain of AF-6, and this interaction was inhibited by activated Ras. AF-6 accumulated with ZO-1 at the cell-cell contact sites in cells lacking tight junctions such as Rat1 fibroblasts and PC12 rat pheochromocytoma cells. The overexpression of activated Ras in Rat1 cells resulted in the perturbation of cell-cell contacts, followed by a decrease of the accumulation of AF-6 and ZO-1 at the cell surface. These results indicate that AF-6 serves as one of the peripheral components of tight junctions in epithelial cells and cell-cell adhesions in nonepithelial cells, and that AF-6 may participate in the regulation of cell-cell contacts, including tight junctions, via direct interaction with ZO-1 downstream of Ras.


Asunto(s)
Células Epiteliales/fisiología , Cinesinas/fisiología , Proteínas de la Membrana/fisiología , Miosinas/fisiología , Fosfoproteínas/fisiología , Uniones Estrechas/fisiología , Proteínas ras/fisiología , Animales , Calcio/fisiología , Bovinos , Comunicación Celular , Línea Celular , Proteínas del Citoesqueleto/metabolismo , Perros , Células Epiteliales/metabolismo , Fibroblastos , Intestinos , Riñón , Cinesinas/genética , Cinesinas/metabolismo , Cinesinas/ultraestructura , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/ultraestructura , Ratones , Microscopía Inmunoelectrónica , Miosinas/genética , Miosinas/metabolismo , Miosinas/ultraestructura , Ocludina , Células PC12 , Fosfoproteínas/metabolismo , Fosfoproteínas/ultraestructura , Ratas , Proteínas Recombinantes/metabolismo , Uniones Estrechas/metabolismo , Uniones Estrechas/ultraestructura , Proteína de la Zonula Occludens-1 , alfa Catenina , Proteínas ras/metabolismo
16.
J Cell Biol ; 125(5): 1095-107, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7515068

RESUMEN

Neurons are highly polarized cells composed of dendrites, cell bodies, and long axons. Because of the lack of protein synthesis machinery in axons, materials required in axons and synapses have to be transported down the axons after synthesis in the cell body. Fast anterograde transport conveys different kinds of membranous organelles such as mitochondria and precursors of synaptic vesicles and axonal membranes, while organelles such as endosomes and autophagic prelysosomal organelles are conveyed retrogradely. Although kinesin and dynein have been identified as good candidates for microtubule-based anterograde and retrograde transporters, respectively, the existence of other motors for performing these complex axonal transports seems quite likely. Here we characterized a new member of the kinesin super-family, KIF3A (50-nm rod with globular head and tail), and found that it is localized in neurons, associated with membrane organelle fractions, and accumulates with anterogradely moving membrane organelles after ligation of peripheral nerves. Furthermore, native KIF3A (a complex of 80/85 KIF3A heavy chain and a 95-kD polypeptide) revealed microtubule gliding activity and baculovirus-expressed KIF3A heavy chain demonstrated microtubule plus end-directed (anterograde) motility in vitro. These findings strongly suggest that KIF3A is a new motor protein for the anterograde fast axonal transport.


Asunto(s)
Transporte Axonal , Cinesinas/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Microtúbulos/metabolismo , Neuronas/metabolismo , Animales , Transporte Biológico Activo , Encéfalo/metabolismo , Compartimento Celular , Movimiento Celular , Femenino , Técnica del Anticuerpo Fluorescente , Cinesinas/química , Ratones , Proteínas Recombinantes , Porcinos , Distribución Tisular , Tubulina (Proteína)/metabolismo
17.
J Cell Biol ; 139(4): 951-61, 1997 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-9362513

RESUMEN

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.


Asunto(s)
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 Tisular
18.
J Cell Biol ; 145(2): 347-61, 1999 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-10209029

RESUMEN

Adducin is a membrane skeletal protein that binds to actin filaments (F-actin) and thereby promotes the association of spectrin with F-actin to form a spectrin-actin meshwork beneath plasma membranes such as ruffling membranes. Rho-associated kinase (Rho- kinase), which is activated by the small guanosine triphosphatase Rho, phosphorylates alpha-adducin and thereby enhances the F-actin-binding activity of alpha-adducin in vitro. Here we identified the sites of phosphorylation of alpha-adducin by Rho-kinase as Thr445 and Thr480. We prepared antibody that specifically recognized alpha-adducin phosphorylated at Thr445, and found by use of this antibody that Rho-kinase phosphorylated alpha-adducin at Thr445 in COS7 cells in a Rho-dependent manner. Phosphorylated alpha-adducin accumulated in the membrane ruffling area of Madin-Darby canine kidney (MDCK) epithelial cells and the leading edge of scattering cells during the action of tetradecanoylphorbol-13-acetate (TPA) or hepatocyte growth factor (HGF). The microinjection of Botulinum C3 ADP-ribosyl-transferase, dominant negative Rho-kinase, or alpha-adducinT445A,T480A (substitution of Thr445 and Thr480 by Ala) inhibited the TPA-induced membrane ruffling in MDCK cells and wound-induced migration in NRK49F cells. alpha-AdducinT445D,T480D (substitution of Thr445 and Thr480 by Asp), but not alpha-adducinT445A,T480A, counteracted the inhibitory effect of the dominant negative Rho-kinase on the TPA-induced membrane ruffling in MDCK cells. Taken together, these results indicate that Rho-kinase phosphorylates alpha-adducin downstream of Rho in vivo, and that the phosphorylation of adducin by Rho-kinase plays a crucial role in the regulation of membrane ruffling and cell motility.


Asunto(s)
Proteínas de Unión a Calmodulina/metabolismo , Citoesqueleto/fisiología , Proteínas Activadoras de GTPasa , Proteínas Serina-Treonina Quinasas/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas de Unión a Calmodulina/química , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/fisiología , Membrana Celular/ultraestructura , Movimiento Celular , Proteínas del Citoesqueleto/metabolismo , Citoesqueleto/efectos de los fármacos , Citoesqueleto/ultraestructura , Perros , Proteínas de Unión al GTP/metabolismo , Factor de Crecimiento de Hepatocito/farmacología , Humanos , Péptidos y Proteínas de Señalización Intracelular , Riñón , Modelos Biológicos , Datos de Secuencia Molecular , Oligopéptidos/síntesis química , Oligopéptidos/química , Oligopéptidos/metabolismo , Fragmentos de Péptidos/química , Fragmentos de Péptidos/aislamiento & purificación , Fosforilación , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Acetato de Tetradecanoilforbol/farmacología , Treonina , Quinasas Asociadas a rho
19.
Science ; 275(5304): 1308-11, 1997 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-9036856

RESUMEN

The small guanosine triphosphatase (GTPase) Rho is implicated in the formation of stress fibers and focal adhesions in fibroblasts stimulated by extracellular signals such as lysophosphatidic acid (LPA). Rho-kinase is activated by Rho and may mediate some biological effects of Rho. Microinjection of the catalytic domain of Rho-kinase into serum-starved Swiss 3T3 cells induced the formation of stress fibers and focal adhesions, whereas microinjection of the inactive catalytic domain, the Rho-binding domain, or the pleckstrin-homology domain inhibited the LPA-induced formation of stress fibers and focal adhesions. Thus, Rho-kinase appears to mediate signals from Rho and to induce the formation of stress fibers and focal adhesions.


Asunto(s)
Actinas/metabolismo , Adhesión Celular , Proteínas Serina-Treonina Quinasas/metabolismo , Células 3T3 , Adenosina Trifosfato/metabolismo , Animales , Sitios de Unión , Línea Celular , ADN Complementario/genética , Inhibidores Enzimáticos/farmacología , GTP Fosfohidrolasas/metabolismo , Péptidos y Proteínas de Señalización Intracelular , Lisofosfolípidos/farmacología , Ratones , Mutación , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética , Proteínas Recombinantes de Fusión/metabolismo , Estaurosporina/farmacología , Quinasas Asociadas a rho
20.
Science ; 281(5378): 832-5, 1998 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-9694656

RESUMEN

The small guanosine triphosphatases (GTPases) Cdc42 and Rac1 regulate E-cadherin-mediated cell-cell adhesion. IQGAP1, a target of Cdc42 and Rac1, was localized with E-cadherin and beta-catenin at sites of cell-cell contact in mouse L fibroblasts expressing E-cadherin (EL cells), and interacted with E-cadherin and beta-catenin both in vivo and in vitro. IQGAP1 induced the dissociation of alpha-catenin from a cadherin-catenin complex in vitro and in vivo. Overexpression of IQGAP1 in EL cells, but not in L cells expressing an E-cadherin-alpha-catenin chimeric protein, resulted in a decrease in E-cadherin-mediated cell-cell adhesive activity. Thus, IQGAP1, acting downstream of Cdc42 and Rac1, appears to regulate cell-cell adhesion through the cadherin-catenin pathway.


Asunto(s)
Cadherinas/metabolismo , Adhesión Celular , Proteínas de Ciclo Celular/metabolismo , GTP Fosfohidrolasas/metabolismo , Proteínas de Unión al GTP/metabolismo , Proteínas/metabolismo , Transactivadores , Animales , Membrana Celular/metabolismo , Proteínas del Citoesqueleto/metabolismo , Proteínas Activadoras de GTPasa , Células L , Ratones , Mutación , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes/metabolismo , alfa Catenina , beta Catenina , Proteína de Unión al GTP cdc42 , Proteínas de Unión al GTP rac
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