RESUMO
Vascular endothelial growth factor-A (VEGF-A) is a critical angiogenic factor which is mainly secreted from podocytes and epithelial cells in kidney and plays an important role in renal pathophysiology. In recent years, functions of different isoforms of VEGF-A and the new secretion approach via extracellular vesicles (EVs) have been identified. Thus, further understanding are needed for the role of VEGF-A and its isoforms in renal injury and repair. In this review, we summarized the expression, secretion and regulation of VEGF-A, its biological function, and the role of different isoforms of VEGF-A in the development of different renal diseases. Meanwhile, the research progress of VEGF-A as diagnostic marker and therapeutic target for renal diseases were discussed.
Assuntos
Humanos , Rim/metabolismo , Nefropatias , Isoformas de Proteínas/metabolismo , Fator A de Crescimento do Endotélio Vascular/fisiologiaRESUMO
Abstract Metallothioneins are a superfamily of low-molecular-weight, cysteine (Cys)-rich proteins that are believed to play important roles in protection against metal toxicity and oxidative stress. The main purpose of this study was to investigate the effect of heterologous expression of a rice metallothionein isoform (OsMTI-1b) on the tolerance of Saccharomyces cerevisiae to Cd2+, H2O2 and ethanol stress. The gene encoding OsMTI-1b was cloned into p426GPD as a yeast expression vector. The new construct was transformed to competent cells of S. cerevisiae. After verification of heterologous expression of OsMTI-1b, the new strain and control were grown under stress conditions. In comparison to control strain, the transformed S. cerevisiae cells expressing OsMTI-1b showed more tolerance to Cd2+ and accumulated more Cd2+ ions when they were grown in the medium containing CdCl2. In addition, the heterologous expression of GST-OsMTI-1b conferred H2O2 and ethanol tolerance to S. cerevisiae cells. The results indicate that heterologous expression of plant MT isoforms can enhance the tolerance of S. cerevisiae to multiple stresses.
Assuntos
Proteínas de Plantas/genética , Oryza/genética , Saccharomyces cerevisiae/metabolismo , Cádmio/metabolismo , Expressão Gênica , Etanol/metabolismo , Peróxido de Hidrogênio/metabolismo , Metalotioneína/genética , Proteínas de Plantas/metabolismo , Saccharomyces cerevisiae/genética , Estresse Oxidativo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Metalotioneína/metabolismoRESUMO
Introducción: La alopecia infantil es una afección poco frecuente en la consulta dermatológica pediátrica. Su etiología es variable según el grupo etario estudiado. El objetivo fue estudiar la causa de alopecia en niños en 2 hospitales pediátricos de referencia nacional en Chile. Pacientes y método: Análisis descriptivo de registros clínicos del total de pacientes atendidos entre enero de 2007 y junio de 2010 en los Servicios de Dermatología de los Hospitales Roberto del Río y Luis Calvo Mackenna. Se incluyeron pacientes con diagnóstico clínico de alopecia. Resultados: Se encontraron 345 registros clínicos, 179 varones (51,9%). La mediana de edad fue 72 meses. Los diagnósticos más prevalentes fueron alopecia areata (AA) (36,8%), tiña capitis (TC) (21%), nevo sebáceo (13,2%) y efluvio telógeno (8,7%). Según el grupo etario predominaron en recién nacidos: aplasia cutis y nevo sebáceo; en lactantes, preescolares y escolares: nevo sebáceo, AA y TC. En escolares se agregó tricotilomanía. En adolescentes nevo sebáceo, AA y efluvio telógeno. Se observó una correlación significativa entre AA con enfermedad autoinmune, enfermedad tiroidea, alteraciones ungueales, enfermedad psiquiátrica y síndrome de Down. En TC el agente etiológico más prevalente fue Microsporum Canis (86,6%). La tricotilomanía se correlacionó con enfermedad psiquiátrica significativamente. Conclusiones: Las principales causas de alopecia infantil fueron adquiridas y no cicatriciales. La etiología varía de acuerdo al grupo etario estudiado. Algunos tipos de alopecia infantil presentaron alta prevalencia de enfermedad psiquiátrica.
Introduction: Childhood alopecia is a relative rare event in general paediatric dermatology practice. Hair loss in children may have multiple causes, and there are different types of alopecia according to age groups. The aim of the study was to describe the clinical and epidemiological profile of alopecia in children from two Chilean paediatric hospitals. Patients and method: Descriptive analysis of clinical records of patients from the Dermatology Department of Roberto del Rio and Luis Calvo Mackenna Hospitals between January 2007 and June 2010. Patients with clinical diagnosis of alopecia were included. Results: A total of 345 clinical records were analysed, with 179 males (51.9%). The median age was 72 months. Overall, the most common diagnoses were: alopecia areata (AA), (36.8%), tinea capitis (TC), (21%), nevus sebaceous (13.2%), and tellogen effluvium (8.7%). According to age groups, in newborns, the most common causes were aplasia cutis and nevus sebaceous. In toddlers, pre-school and school children, the principal causes were nevus sebaceous, AA and TC. Trichotillomania was also significant in school children. In adolescents, nevus sebaceous, AA and tellogen effluvium were the most frequent diagnoses. AA was statistically associated with autoimmune disease, thyroid disease, nail disorder, psychiatric disease, and Down's syndrome. The most common aetiological agent in TC was M. canis (86.6%). Trichotillomania was also statistically associated to psychiatric disorders. Conclusions: In this study, the main causes of alopecia in children were acquired and non-scarring alopecia. In our results, the type of alopecia varies according to age group. Some types of childhood alopecia showed a close correlation to psychiatric disorders.
Assuntos
Humanos , Permeabilidade da Membrana Celular/fisiologia , Claudinas/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Harringtoninas/metabolismo , Intestinos/metabolismo , Isoformas de Proteínas/metabolismo , Linhagem Celular Tumoral , Dextranos/metabolismo , /análogos & derivados , /metabolismo , Intestinos/fisiologia , Junções Íntimas/metabolismo , Junções Íntimas/fisiologia , Transcrição Gênica/fisiologiaRESUMO
Introduction Parotid gland incidentalomas (PGIs) are unexpected hypermetabolic foci in the parotid region that can be found when scanning with whole-body positron emission/computed tomography (PET/CT). These deposits are most commonly due to benign lesions such as Warthin tumor. Objective The aim of this study was to determine the prevalence of PGIs identified in PET/CT scans and to assess the role of smoking in their etiology. Methods We retrospectively reviewed all PET/CT scans performed at our center in search of PGIs and identified smoking status and standardized uptake value (SUVmax) in each case. We also analyzed the database of parotidectomies performed in our department in the previous 10 years and focused on the pathologic diagnosis and the presence or absence of smoking in each case. Results Sixteen cases of PGIs were found in 4,250 PET/CT scans, accounting for 0.4% . The average SUVmax was 6.5 (range 2.8 to 16). Cytology was performed in five patients; it was benign in four cases and inconclusive in one case. Thirteen patients had a history of smoking. Of the parotidectomies performed in our center with a diagnosis of Warthin tumor, we identified a history of smoking in 93.8% of those patients. Conclusions The prevalence of PGIs on PET/CT was similar to that reported by other authors. Warthin tumor is frequently diagnosed among PGIs on PET/CT, and it has a strong relationship with smoking. We suggest that a diagnosis other than Warthin tumor should be considered for PGIs in nonsmokers. .
Assuntos
Humanos , Proteínas ADAM/metabolismo , Proteólise , Fator de von Willebrand/química , Fator de von Willebrand/metabolismo , Sítios de Ligação , Cálcio/metabolismo , Dissulfetos/química , Dissulfetos/metabolismo , Ligação de Hidrogênio , Modelos Moleculares , Mutagênese Sítio-Dirigida , Ligação Proteica , Estabilidade Proteica , Estrutura Terciária de Proteína , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Fator de von Willebrand/genéticaRESUMO
OBJECTIVE: To analyze the association between the length of napping during the night shift and the recovery after work among nurses. METHOD: Cross-sectional epidemiological study involving 1940 nurses from 18 public hospitals in the City of Rio de Janeiro. A multidimensional and self-applied questionnaire was used with information about health, sociodemographic and occupational characteristics, health-related behaviors and housework. Multiple logistic regression was applied to identify the association, adjusted for confounding variables. RESULTS: The gross analyses showed 44%, 127% and 66% higher chances of a high level of recovery after work for nurses who sleep up to two hours, between 2.1 and 3 hours and 3.1 hours or more, respectively, when compared to the nurses who do not sleep. After adjusting for confounding variables, the association only continues significant for the group that sleeps 2.1 to 3 hours during the night shift (OR=1.79; 95%CI=1.33-2.41). CONCLUSION: The association between the length of napping and the high level of recovery after work, confirmed in the present results, can be included in the studies that aim to support more appropriate policies aimed at improving the workers' work, life and health conditions, not only in nursing, but night-shift workers in general. .
OBJETIVO: analisar a associação entre duração do cochilo durante o plantão noturno e recuperação após o trabalho, entre enfermeiros. MÉTODO: estudo epidemiológico seccional com 1940 enfermeiros, de 18 hospitais públicos, do Município do Rio de Janeiro. Utilizou-se questionário multidimensional e autopreenchível com informações sobre saúde, características sociodemográficas, ocupacionais, comportamentos relacionados à saúde e trabalho doméstico. Utilizou-se a regressão logística múltipla, buscando identificar a associação ajustada por variáveis de confundimento. RESULTADOS: as análises brutas mostraram chances 44%, 127% e 66% mais elevadas de alta recuperação após o trabalho, para aqueles que dormem até 2 horas, de 2,1 a 3 horas e de 3,1 horas ou mais, respectivamente, comparados aos que não dormem. Após o ajuste por variáveis de confundimento, a associação permanece significativa apenas para o grupo que dorme de 2,1 a 3 horas durante o plantão noturno (OR=1,79; IC95%=1,33-2,41). CONCLUSÃO: a associação entre tempo de cochilo e alta recuperação após o trabalho, confirmada nos resultados, pode compor os estudos que buscam subsidiar políticas mais adequadas voltadas à melhoria das condições de trabalho, de vida e saúde dos trabalhadores, não apenas da enfermagem, mas trabalhadores noturnos de forma geral. .
OBJETIVO: Analizar la asociación entre la duración de la siesta durante la guardia nocturna y la recuperación tras el trabajo entre enfermeros. MÉTODO: Estudio epidemiológico seccional con 1940 enfermeros de dieciocho hospitales públicos del Municipio de Rio de Janeiro. Fue utilizado cuestionario tipo multidimensional y autollenado con informaciones sobre salud, características sociodemográficas, ocupacionales, comportamientos relacionados a la salud y trabajo doméstico. Fue utilizada la regresión logística múltipla, buscando identificar la asociación ajustada por variables de confusión. RESULTADOS: Los análisis brutos mostraron posibilidades 44%, 127% y 66% más elevadas de alta recuperación tras el trabajo, para aquellos que duermen hasta 2 horas, de 2,1 a 3 horas y de 3,1 horas o más, respectivamente, comparados a aquellos que no duermen. Tras el ajuste por variables de confusión, la asociación sigue significativa solamente para el grupo que duerme de 2,1 a 3 horas durante la guardia nocturna (OR=1,79; IC95%=1,33-2,41). CONCLUSIÓN: La asociación entre el tiempo de siesta y la alta recuperación tras el trabajo, confirmada en nuestros resultados, puede componer los estudios con objeto de subsidiar políticas más adecuadas dirigidas a la mejora de las condiciones de trabajo, de vida y salud de los trabajadores, no solamente enfermeros, pero trabajadores nocturnos de manera general. .
Assuntos
Humanos , Masculino , Calicreínas/metabolismo , Neoplasias da Próstata/metabolismo , Biomarcadores Tumorais/metabolismo , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/diagnóstico , Isoformas de Proteínas/metabolismo , Fatores de RiscoRESUMO
BACKGROUND/AIMS: Fibroblast growth factor signaling is involved in hepatocarcinogenesis. The aim of this study was to determine the fibroblast growth factor receptor (FGFR) isotype expression in hepatocellular carcinoma (HCC) and neighboring nonneoplastic liver tissue, and elucidate its prognostic implications. METHODS: Immunohistochemical staining of FGFR1, -2, -3, and -4 was performed in the HCCs and paired neighboring nonneoplastic liver tissue of 870 HCC patients who underwent hepatic resection. Of these, clinical data for 153 patients who underwent curative resection as a primary therapy were reviewed, and the relationship between FGFR isotype expression and overall survival was evaluated (development set). This association was also validated in 73 independent samples (validation set) by Western blot analysis. RESULTS: FGFR1, -2, -3, and -4 were expressed in 5.3%, 11.1%, 3.8%, and 52.7% of HCCs, respectively. Among the development set of 153 patients, FGFR2 positivity in HCC was associated with a significantly shorter overall survival (5-year survival rate, 35.3% vs. 61.8%; P=0.02). FGFR2 expression in HCC was an independent predictor of a poor postsurgical prognosis (hazard ratio, 2.10; P=0.02) in the development set. However, the corresponding findings were not statistically significant in the validation set. CONCLUSIONS: FGFR2 expression in HCC could be a prognostic indicator of postsurgical survival.
Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Western Blotting , Carcinoma Hepatocelular/metabolismo , Hepatectomia , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/metabolismo , Prognóstico , Modelos de Riscos Proporcionais , Isoformas de Proteínas/metabolismo , Receptores de Fatores de Crescimento de Fibroblastos/metabolismoRESUMO
OBJECTIVE: Certain drug classes alleviate the symptoms of Willis-Ekbom's disease, whereas others aggravate them. The pharmacological profiles of these drugs suggest that drugs that alleviate Willis-Ekbom's disease inhibit thyroid hormone activity, whereas drugs that aggravate Willis-Ekbom's disease increase thyroid hormone activity. These different effects may be secondary to the opposing actions that drugs have on the CYP4503A4 enzyme isoform. Drugs that worsen the symptoms of the Willis-Ekbom's disease inhibit the CYP4503A4 isoform, and drugs that ameliorate the symptoms induce CYP4503A4. The aim of this study is to determine whether Saint John's wort, as an inducer of the CYP4503A4 isoform, diminishes the severity of Willis-Ekbom's disease symptoms by increasing the metabolism of thyroid hormone in treated patients. METHODS: In an open-label pilot trial, we treated 21 Willis-Ekbom's disease patients with a concentrated extract of Saint John's wort at a daily dose of 300 mg over the course of three months. RESULTS: Saint John's wort reduced the severity of Willis-Ekbom's disease symptoms in 17 of the 21 patients. CONCLUSION: Results of this trial suggest that Saint John's wort may benefit some Willis-Ekbom's disease patients. However, as this trial was not placebo-controlled, the extent to which Saint John's wort is effective as a Willis-Ekbom's disease treatment will depend on future, blinded placebo-controlled studies. .
Assuntos
Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , /efeitos dos fármacos , Hypericum , Extratos Vegetais/uso terapêutico , Síndrome das Pernas Inquietas/tratamento farmacológico , Fatores Etários , /antagonistas & inibidores , /metabolismo , Isoformas de Proteínas/efeitos dos fármacos , Isoformas de Proteínas/metabolismo , Síndrome das Pernas Inquietas/enzimologia , Índice de Gravidade de Doença , Resultado do Tratamento , Hormônios Tireóideos/metabolismoRESUMO
The purpose of this study is to determine 1) whether morphine postconditiong (MPostC) can attenuate the intercellular adhesion molecules-1 (ICAM-1) expression after reoxygenation injury and 2) the subtype(s) of the opioid receptors (ORs) that are involved with MPostC. Human umbilical vein endothelial cells (HUVECs) were subjected to 6 hr anoxia followed by 12 hr reoxygenation. Three morphine concentrations (0.3, 3, 30 microM) were used to evaluate the protective effect of MPostC. We also investigated blockading the OR subtypes' effects on MPostC by using three antagonists (a micro-OR antagonist naloxone, a kappa-OR antagonist nor-binaltorphimine, and a delta-OR antagonist naltrindole) and the inhibitor of protein kinase C (PKC) chelerythrine. As results, the ICAM-1 expression was significantly reduced in the MPostC (3, 30 microM) groups compared to the control group at 1, 6, 9, and 12 hours reoxygenation time. As a consequence, neutrophil adhesion was also decreased after MPostC. These effects were abolished by coadministering chelerythrine, nor-binaltorphimine or naltrindole, but not with naloxone. In conclusion, it is assumed that MPostC could attenuate the expression of ICAM-1 on endothelial cells during reoxygenation via the kappa and delta-OR (opioid receptor)-specific pathway, and this also involves a PKC-dependent pathway.
Assuntos
Animais , Humanos , Benzofenantridinas/farmacologia , Células Endoteliais/citologia , Endotélio Vascular/citologia , Molécula 1 de Adesão Intercelular/genética , Morfina/farmacologia , Naloxona/farmacologia , Naltrexona/análogos & derivados , Antagonistas de Entorpecentes/farmacologia , Entorpecentes/farmacologia , Isoformas de Proteínas/metabolismo , Proteína Quinase C/antagonistas & inibidores , Receptores Opioides/metabolismo , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/fisiologia , Veias Umbilicais/citologiaRESUMO
PURPOSE: Radiotherapy for head and neck cancer does not impair the voice quality as much as laser treatment or surgery, but it can induce muscle wasting and fibrosis and symptoms of dry mouth. We investigated the effect of irradiation on the myosin heavy chain (MyHC) expression in laryngeal muscles. MATERIALS AND METHODS: Rats were irradiated with one dose of 10, 15, 20, 25, 30, or 35 Gy and other rats were irradiated with 20 Gy. The thyroarytenoid (TA), posterior cricoarytenoid (PCA), and cricothyroid (CT) muscles were subjected to reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Two weeks after irradiation with 10, 15, or 20 Gy, all the MyHC type expressions had decreased in a dose-dependent manner in the TA, PCA, and CT muscles, and especially the expression of MyHC IIa decreased much more than the expressions of the other MyHC isoforms in all muscles. In the 20 Gy-irradiated rats, almost all the MyHC isoform expressions declined over 12 weeks in the TA, PCA, and CT muscles, except for the MyHC I expression in the PCA and CT muscle. The MyHC IIa expression was markedly decreased in all the muscles. CONCLUSION: The laryngeal muscles responded differently to radiation, but they showed a time-dependent and long-lasting decrease in the expressions of all the MyHC isoforms in the TA, PCA, and CT muscles. In particular, the expression of the MyHC IIa isoform in all the muscles may be more sensitive to irradiation than the expressions of the other MyHC isoforms.
Assuntos
Animais , Ratos , Peso Corporal/efeitos da radiação , Expressão Gênica/efeitos da radiação , Músculos Laríngeos/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Isoformas de Proteínas/metabolismo , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Inhibin, which is important for normal gonadal function, acts on the pituitary gonadotropins to suppress folliclestimulating hormone (FSH) secretion. The level and cellular localization of the inhibin isotypes, alpha, beta(A) and beta(B), in the testis of mice were examined during postnatal development in order to determine if inhibin expression is related to testicular maturation. Mouse testes were sampled on postnatal days (PNDs) 1, 3, 6, 18, 48 and 120, and analyzed by Western blotting and immunofluorescence. Western blot analysis showed very low levels of inhibin alpha, beta(A) and beta(B) expression in the testes at days 1 to 6 after birth. The levels then increased gradually from PND 18 to 48-120, and there were significant peaks at PND 48. Inhibin alpha, beta(A) and beta(B) were detected in testicular cells during postnatal development using immunohistochemistry. The immunoreactivity of inhibin alpha was rarely observed in testicular cells during PND 1 to 6, or in the cytoplasmic process of Sertoli cells surrounding the germ cells and interstitial cells during PND 18 to 120. Inhibin beta(A) and beta(B) immunoreactivity was rarely observed in the testis from PND 1 to 6. On the other hand, it was observed in some spermatogonial cells, as well as in the interstitial space between PND 48 and PND 120. We conclude that the expression of inhibin isotypes increases progressively in the testis of mice with increasing postnatal age, suggesting that inhibin is associated with a negative feedback signal for FSH in testicular maturation.
Assuntos
Animais , Masculino , Camundongos , Envelhecimento/fisiologia , Regulação da Expressão Gênica/fisiologia , Subunidades beta de Inibinas/genética , Inibinas/genética , Camundongos Endogâmicos ICR , Isoformas de Proteínas/metabolismo , Transporte Proteico/fisiologia , Testículo/metabolismoRESUMO
Survivin variants specific real time quantitative RT-PCR was developed to analyze their expression in 53 paired cancer and para-cancerous tissues, and the expression of the wild-type survivin protein was detected by immunohistochemistry. The results showed that survivin mRNA and protein were expressed in gastric cancer and para-cancerous tissues. The survivin-2B was dominantly expressed in para-cancerous tissues, whereas the survivin-DeltaEx3 was more frequently detected in cancer tissues. The positive rate of survivin-2a was 100% in both cancer and para-cancerous tissues, but its relative transcript expression level was not significantly increased in cancer tissues in comparison with para-cancerous tissues. The correlation analysis revealed that the expression of survivin-2a mRNA was significantly associated with that of total survivin (r (s)=0.4178, P=0.0018), whereas inversely to that of survivin-DeltaEX3 (r (s)=-0.4506, P=0.0007). It was suggested that survivin-2a may act as an antagonist of survivin-DeltaEX3. The balance between antiapoptotic survivin iso-forms and nonantiapoptotic ones may play an important role in tumorigenesis and tumor progression. Promising value is hinted to analyze survivin and its variants in tumor early diagnosis and distinguishing malignant tumors from benign ones.
Assuntos
Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Células Tumorais Cultivadas , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismoRESUMO
Trichostatin A (TSA), originally developed as an antifungal agent, is one of potent histone deacetylase (HDAC) inhibitors, which are known to cause growth arrest and apoptosis induction of transformed cells, including urinary bladder, breast, prostate, ovary, and colon cancers. However, the effect of HDAC inhibitors on human non-small cell lung cancer cells is not clearly known yet. Herein, we demonstrated that treatment of TSA resulted in a significant decrease of the viability of H157 cells in a dose-dependent manner, which was revealed as apoptosis accompanying with nuclear fragmentation and an increase in sub-G0/G1 fraction. In addition, it induced the expression of Fas/FasL, which further triggered the activation of caspase-8. Catalytic activation of caspase-9 and decreased expression of anti-aptototic Bcl-2 and Bcl-XL proteins were observed in TSA-treated cells. Catalytic activation of caspase-3 by TSA was further confirmed by cleavage of pro-caspase-3 and intracellular substrates, including poly (ADP-ribose) polymerase (PARP) and inhibitor of caspase-activated deoxyribonuclease (ICAD). In addition, a characteristic phenomenon of mitochondrial dysfunction, including mitochondrial membrane potential transition and release of mitochondrial cytochrome c into the cytosol was apparent in TSA-treated cells. Taken together, our data indicate that inhibition of HDAC by TSA induces the apoptosis of H157 cells through signaling cascade of Fas/FasL-mediated extrinsic and mitocondria-mediated intrinsic caspases pathway.
Assuntos
Humanos , Transdução de Sinais , Receptores de Morte Celular/metabolismo , Isoformas de Proteínas/metabolismo , Mitocôndrias/efeitos dos fármacos , Neoplasias Pulmonares/metabolismo , Ácidos Hidroxâmicos/farmacologia , Histonas/metabolismo , Ativação Enzimática , Linhagem Celular Tumoral , Catálise , Caspase 9/metabolismo , Caspase 8/metabolismo , Caspase 3/metabolismo , Apoptose/efeitos dos fármacos , AcetilaçãoRESUMO
Synaptotagmin is a Ca2+ sensing protein, which triggers a fusion of synaptic vesicles in neuronal transmission. Little is known regarding the expression of Ca2+ - dependent synaptotagmin isoforms and their contribution to the release of secretory vesicles in mouse and rat parotid acinar cells. We investigated a type of Ca2+ - dependent synaptotagmin and Ca2+ signaling in both rat and mouse parotid acinar cells using RT-PCR, microfluorometry, and amylase assay. Mouse parotid acinar cells exhibited much more sensitive amylase release in response to muscarinic stimulation than did rat parotid acinar cells. However, transient [Ca2+]i increases and Ca2+ influx in response to muscarinic stimulation in both cells were identical, suggesting that the expression or activity of the Ca2+ sensing proteins is different. Seven Ca2+ - dependent synaptotagmins, from 1 to 7, were expressed in the mouse parotid acinar cells. However, in the rat parotid acinar cells, only synaptotagmins 1, 3, 4 and 7 were expressed. These results indicate that the expression of Ca2+ - dependent synaptotagmins may contribute to the release of secretory vesicles in parotid acinar cells.
Assuntos
Ratos , Camundongos , Animais , Sinaptotagminas/metabolismo , Transdução de Sinais , Isoformas de Proteínas/metabolismo , Glândula Parótida/citologia , Agonistas Muscarínicos/farmacologia , Exocitose/efeitos dos fármacos , Carbacol/farmacologia , Cálcio/metabolismo , Amilases/metabolismoRESUMO
The Met tyrosine kinase receptor is a widely expressed molecule, which mediates pleiotropic cellular responses following activation by its ligand, hepatocyte growth factor/scatter factor (HGF/SF). Previously, one of the authors identified an alternatively spliced form of Met (Met-SM) that lacked a single exon of a 47-amino-acid segment in the juxtamembrane domain. Here we report that Met-SM is a potent transforming gene in NIH3T3 mouse fibroblast cells. Met-SM-transfected NIH3T3 cells show stronger foci-forming activity than wild type-Met-transfected ones. In addition, Met-SM-transfected NIH3T3 cells form colonies in soft agar and are tumorigenic in athymic nu/nu mice. Furthermore, HGF/SF significantly increases the focus-forming activity of Met-SM comparing to wild type Met. The amount of protein and of tyrosine kinase activity of Met-SM accumulates to a high level following HGF/SF treatment. The accumulation of Met-SM correlated well with its delayed ubiquitination and increased stability. These results are consistent with the important role of the juxtamembrane domain in protein stability of Met receptor and suggest that the alternatively-spliced form may contribute to the development and progression of human cancer.
Assuntos
Camundongos , Feminino , Animais , Proteínas Proto-Oncogênicas c-met/metabolismo , Isoformas de Proteínas/metabolismo , Células NIH 3T3 , Proteínas Mutantes/metabolismo , Camundongos Nus , Fator de Crescimento de Hepatócito/farmacologia , Regulação para Baixo , Carcinógenos/metabolismo , Testes de Carcinogenicidade , Processamento AlternativoRESUMO
The three mammalian isoforms of transforming growth factor-beta (TGF-beta1, beta2, beta3) are potent regulators of cell growth, differentiation, and extracellular matrix deposition. To study their role in skin differentiation, we investigated the expression of TGF-beta isoforms on cell growth and differentiation induction of the human keratinocyte cell line, HaCaT by elevating the Ca2+ concentration. An ELISA and RT-PCR assay revealed secreted TGF-beta 1 protein and TGF-beta1 mRNA were increased during calci-um-induced differentiation. In contrast, major differences were seen for TGF-beta 2 and TGF-beta 3 mRNA which were decreased during differentiation, but TGF-beta 2 and TGF-3beta protein were not evident on an ELISA. These results suggest different functions for each TGF-beta isoforms in epidermal differentiation, such that TGF-beta 1 is associ-ated with the more differentiated state, and TGF-beta 2 and TGF-beta 3 may be associ-ated the more proliferated state.
Assuntos
Humanos , Diferenciação Celular/fisiologia , Linhagem Celular , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Queratinócitos/citologia , Isoformas de Proteínas/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
Arginine methylation has been implicated in the signal transduction pathway leading to cell growth. Here we show that a regenerating rat liver following partial hepatectomy exhibited elevated methyltransferase activity as shown by increased methylation of a subset of endogenous proteins in vitro. The 20-kDa protein was shown to be a major cytosolic protein undergoing methylation in regenerating hepatocytes. Methylation of the 20-kDa protein peaked at 1 d following partial hepatectomy, which gradually declined to a basal level within the next 14 d. Likewise, methylation of exogenously added bulk histones followed the similar time kinetics as the 20-kDa protein, reflecting time-dependent changes in methyltransferase activity in regenerating hepatocytes. Presence of exogenously added bulk histone in the in vitro methylation assay resulted in dose-dependent inhibition of methylation of the 20-kDa protein. All the histone subtypes tested, histone 1, 2A, 2B, 3 or 4, were able to inhibit methylation of the 20-kDa protein while addition of cytochrome C, a-lactalbumin, carbonic anhydrase, bovine serum albumin, and g globulin minimally affected methylation of the 20-kDa protein. Since methylation of the 20-kDa protein preceded proliferation of hepatocytes upon partial hepatectomy, it is tempting to speculate that the methylated 20-kDa protein by activated histone-specific methyltransferase may be involved in an early signal critical for liver regeneration.
Assuntos
Animais , Humanos , Ratos , Citoplasma/química , Hepatectomia , Histonas/metabolismo , Regeneração Hepática/fisiologia , Metilação , Metiltransferases/metabolismo , Isoformas de Proteínas/metabolismo , Proteínas/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , Frações Subcelulares/químicaRESUMO
Over-expression of the human epidermal growth factor receptor-2 (HER2/neu) has been observed in many cancers, and is associated with a poor prognosis. Recent adjuvant treatment with anti-HER2 monoclonal antibodies in breast cancer has increased the demand for an evaluation of the HER2/neu status in breast cancer. The aim of this study was to investigate the HER2/neu status in breast cancer by a real-time quantitative polymerase chain reaction (PCR) method using LightCycler (Roche Diagnostics, Mannheim, Germany). DNA samples from the fresh tumor tissues of 27 patients with breast cancer were analyzed in parallel using immunohistochemistry (IHC) and the other prognostic parameters including estrogen receptor, progesterone receptor, cytokeratin, and DNA ploidy. Ten (37%) out of 27 cases tested were positive for HER2/neu, while 16 (73%) out of 22 tested positive through an IHC study. The correlation between the DNA aneuploidy and the positive results for HER2/neu were only observed using the real-time PCR method (p < 0.05). There was no significant correlation between the HER2/neu status and the S-phase fractions of the DNA ploidy or other parameters. This study demonstrated that there is marked discordance in the results for the HER2/neu status according to the various methods used. Real-time quantitative PCR for HER2/neu appears to be clinically useful due to its simplicity and ability to produce rapid results.
Assuntos
Feminino , Humanos , Neoplasias da Mama/metabolismo , Isoformas de Proteínas/metabolismo , Receptores ErbB/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
In order to determine the precise mechanism of the interactions between different types of cells, which are common phenomena in tissues and organs, the importance of coculture techniques are becoming increasingly important. In the area of cardiology, artificial arteries have been developed, based on the understanding of physiological communication of the arterial smooth muscle cells (SMC), endothelial cells (EC), and the extracellular matrix (ECM). In the study of atherosclerosis, the modification of low-density lipoprotein (LDL), which result in the recruitment and accumulation of white blood cells, especially, monocytes/macrophages, and foam cell formation, are hypothesized. Although there are well known animal models, an in vitro model of atherogenesis with a precisely known atherogenesis mechanism has not yet been developed. In this paper, an arterial wall reconstruction model using rabbit primary cultivated aortic SMCs and ECs, was shown. In addition, human peripheral monocytes were used and the transmigration of monocytes was observed by scanning electron and laser confocal microscopy. Monocyte differentiation into macrophages was shown by immunohistochemistry and comprehensive gene expression analysis. With the modified form of LDL, the macrophages were observed to accumulate lipids with a foamy appearance and differentiate into the foam cells in the ECM between the ECs and SMCs in the area of our coculture model.