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1.
Int J Biol Macromol ; 249: 125890, 2023 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-37479205

RESUMEN

The best amylolytic activity production by Aspergillus clavatus UEM 04 occurred in submersed culture, with starch, for 72 h, at 25 °C, and 100 rpm. Exclusion chromatography partially purified two enzymes, which ran as unique bands in SDS-PAGE with approximately 84 kDa. LC-MS/MS identified a glucoamylase (GH15) and an α-amylase (GH13_1) as the predominant proteins and other co-purified proteins. Zn2+, Cu2+, and Mn2+ activated the glucoamylase, and SDS, Zn2+, Fe3+, and Cu2+ inhibited the α-amylase. The α-amylase optimum pH was 6.5. The optimal temperatures for the glucoamylase and α-amylase were 50 °C and 40 °C, and the Tm was 53.1 °C and 56.3 °C, respectively. Both enzymes remained almost fully active for 28-32 h at 40 °C, but the α-amylase thermal stability was calcium-dependent. Furthermore, the glucoamylase and α-amylase KM for starch were 2.95 and 1.0 mg/mL, respectively. Still, the Vmax was 0.28 µmol/min of released glucose for glucoamylase and 0.1 mg/min of consumed starch for α-amylase. Moreover, the glucoamylase showed greater affinity for amylopectin and α-amylase for maltodextrin. Additionally, both enzymes efficiently degraded raw starch. At last, glucose was the main product of glucoamylase, and α-amylase produced mainly maltose from gelatinized soluble starch hydrolysis.


Asunto(s)
Glucano 1,4-alfa-Glucosidasa , alfa-Amilasas , alfa-Amilasas/metabolismo , Glucano 1,4-alfa-Glucosidasa/metabolismo , Almidón/metabolismo , Cromatografía Liquida , Espectrometría de Masas en Tándem , Glucosa , Concentración de Iones de Hidrógeno
2.
J. coloproctol. (Rio J., Impr.) ; 41(4): 335-339, Out.-Dec. 2021. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1356437

RESUMEN

Objective: To assess the survival rate of patients with colorectal cancer at Hospital Universitário Alzira Vellano, in the municipality of Alfenas, state of Minas Gerais (MG), Brazil, from 2007 to 2016. Methodology: A search was conducted in the laboratory files and medical records of patients diagnosed with colorectal cancer and cared for during the aforementioned period. Results: In total, 128 cases were found: 52.3% were men, and 47.7% were women, with ages ranging from 25 to 91 years. The most common types of cancer in both genders were of the colon, rectum and sigmoid. The most common stages were T3N1Mx, followed by T3N0Mx and T3N2Mx. Patients with T1 or T2 cancers had a 100% survival rate, whereas the rate for those with grade 4 (T4) was of 0%. An association (p<0.05) of the location of the tumor with the survival rate was confirmed. Conclusion: There was a high mortality rate among patients diagnosed with colorectal cancer at Hospital Universitário Alzira Vellano from 2007 to 2016. (AU)


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Neoplasias Intestinales/mortalidad , Tasa de Supervivencia
3.
Brain Res ; 1724: 146424, 2019 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-31472112

RESUMEN

Spinal cord injury (SCI) is a medical condition that currently lacks effective treatment. Galantamine is a reversible, competitive acetylcholinesterase inhibitor, used to treat patients with Alzheimers disease. It has been demonstrated that galantamine increases cerebral neurogenesis and has a neuroprotective effect by binding to nicotinic receptors and has an anti-inflammatory effect due to its allosteric binding to the α7nAChR. In the present study, the effects of galantamine on functional recovery and histological outcome in a rat contusion model of SCI were analyzed. Male Wistar rats were submitted to SCI using a NYU/MASCIS impactor. The animals from the galantamine group were treated with 5 mg/kg galantamine intraperitoneally for 5 days. The Basso, Beattie and Bresnahan scale (BBB) was used to evaluate locomotor activity. The expression of beta3-tubulin, NFM, GFAP, O4, CD68 and CD3 was analyzed by flow cytometry. Rats that received galantamine had significantly higher BBB scores in comparison with the control lesion group. Galantamine treatment increased the percentage of NFM positive cells at 6 weeks post-injury and reduced the size of the lesion. The results indicate that galantamine increased tissue survival and accelerated hind limb motor function recovery. This is the first study that has shown the possibility of therapeutic use of galantamine in a model of acute spinal cord injury.


Asunto(s)
Galantamina/farmacología , Recuperación de la Función/efectos de los fármacos , Traumatismos de la Médula Espinal/tratamiento farmacológico , Animales , Contusiones/patología , Galantamina/metabolismo , Miembro Posterior/fisiopatología , Locomoción/efectos de los fármacos , Masculino , Actividad Motora/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Ratas , Ratas Wistar , Recuperación de la Función/fisiología , Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/fisiopatología
4.
Neurobiol Learn Mem ; 163: 107040, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31310813

RESUMEN

Early life stress such as physical abuse, trauma or neglect during a critical period of development can elicit negative long-lasting effects on health. Neonatal maternal deprivation (MD) is a stressful event capable of triggering structural and neurobiological changes in Central Nervous System (CNS) development during proliferative and migratory cell differentiation. In this study, we investigated the maternal behavior of lactating rats submitted to protocol of chronic neonatal maternal deprivation (MD) during postnatal day (PND) 1 until 10. We analyzed the effects of the MD in the olfactory memory and cellular proliferation and differentiation in the hippocampus and olfactory bulb in Wistar rat pups on 7, 11 and 21 days postpartum. Analysis in active neurons, cellular differentiation and proliferation, were marked and evaluated by flow cytometry in tissue samples of hippocampi and olfactory bulb. Our results demonstrated an increase in maternal behavior immediately after dam's return to the home-cage in MD group compared to the non-deprived group. In addition, MD pups spent more time (higher latency) to identify the nest odor in comparison to the non-deprived rat pups in the olfactory learning task and showed a significant delay in the neural differentiation and proliferation in the hippocampus and olfactory bulb. These results reveal that disruptions in the mother-infant bonding by the MD induce changes in maternal behavior and interaction with the offspring that could be leading to delayed CNS development and significant impairment in offspring's olfactory learning.


Asunto(s)
Aprendizaje/fisiología , Conducta Materna , Privación Materna , Neuronas/fisiología , Animales , Animales Recién Nacidos/crecimiento & desarrollo , Animales Recién Nacidos/fisiología , Femenino , Citometría de Flujo , Hipocampo/crecimiento & desarrollo , Hipocampo/fisiología , Masculino , Memoria/fisiología , Bulbo Olfatorio/crecimiento & desarrollo , Bulbo Olfatorio/fisiología , Embarazo , Ratas , Ratas Wistar , Olfato/fisiología
5.
Regen Med ; 13(7): 785-801, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30289057

RESUMEN

AIM: Scaffolds are a promising approach for spinal cord injury (SCI) treatment. FGF-2 is involved in tissue repair but is easily degradable and presents collateral effects in systemic administration. In order to address the stability issue and avoid the systemic effects, FGF-2 was encapsulated into core-shell microfibers by coaxial electrospinning and its in vitro and in vivo potential were studied. Materials & methods: The fibers were characterized by physicochemical and biological parameters. The scaffolds were implanted in a hemisection SCI rat model. Locomotor test was performed weekly for 6 weeks. After this time, histological analyses were performed and expression of nestin and GFAP was quantified by flow cytometry. Results: Electrospinning resulted in uniform microfibers with a core-shell structure, with a sustained liberation of FGF-2 from the fibers. The fibers supported PC12 cells adhesion and proliferation. Implanted scaffolds into SCI promoted locomotor recovery at 28 days after injury and reduced GFAP expression. CONCLUSION: These results indicate the potential of these microfibers in SCI tissue engineering. [Formula: see text].


Asunto(s)
Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Médula Espinal/patología , Ingeniería de Tejidos/métodos , Andamios del Tejido , Animales , Ensayo de Materiales , Células PC12 , Ratas , Médula Espinal/metabolismo , Médula Espinal/ultraestructura , Traumatismos de la Médula Espinal/terapia
6.
J Proteome Res ; 16(10): 3688-3703, 2017 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-28836437

RESUMEN

Sugar cane is an important crop for sugar and biofuel production. Its lignocellulosic biomass represents a promising option as feedstock for second-generation ethanol production. Nitrogen fertilization can affect differently tissues and its biopolymers, including the cell-wall polysaccharides and lignin. Lignin content and composition are the most important factors associated with biomass recalcitrance to convert cell-wall polysaccharides into fermentable sugars. Thus it is important to understand the metabolic relationship between nitrogen fertilization and lignin in this feedstock. In this study, a large-scale proteomics approach based on GeLC-MS/MS was employed to identify and relatively quantify proteins differently accumulated in two contrasting genotypes for lignin composition after excessive nitrogen fertilization. From the ∼1000 nonredundant proteins identified, 28 and 177 were differentially accumulated in response to nitrogen from IACSP04-065 and IACSP04-627 lines, respectively. These proteins were associated with several functional categories, including carbon metabolism, amino acid metabolism, protein turnover, and oxidative stress. Although nitrogen fertilization has not changed lignin content, phenolic acids and lignin composition were changed in both species but not in the same way. Sucrose and reducing sugars increased in plants of the genotype IACSP04-065 receiving nitrogen.


Asunto(s)
Biocombustibles , Plantas Modificadas Genéticamente/genética , Proteoma/genética , Saccharum/genética , Biomasa , Carbohidratos/química , Carbohidratos/genética , Fermentación , Regulación de la Expresión Génica de las Plantas , Genotipo , Lignina/química , Lignina/metabolismo , Nitrógeno/química , Nitrógeno/metabolismo , Oxidantes/química , Oxidantes/metabolismo , Fenotipo , Plantas Modificadas Genéticamente/metabolismo , Proteoma/química , Saccharum/metabolismo
7.
Islets ; 9(2): 30-42, 2017 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-28151049

RESUMEN

The maintenance of viable and functional pancreatic islets is crucial for successful islet transplantation from brain-dead donors. To overcome islet quality loss during culture, some studies have co-cultured islets with mesenchymal stem/stromal cells (MSC). However, it is still uncertain if MSC-secreted factors are enough to improve islet quality or if a physical contact between MSCs and islets is needed. Therefore, we performed a systematic review and meta-analysis to clarify the effect of different culture contact systems of islets with MSCs on viability and insulin secretion outcomes. Pubmed and Embase were searched. Twenty studies fulfilled the eligibility criteria and were included in the qualitative synthesis and/or meta-analysis. For both outcomes, pooled weighted mean differences (WMD) between islet cultured alone (control group) and the co-culture condition were calculated. Viability mean was higher in islets co-cultured with MSCs compared with islet cultured alone [WMD = 18.08 (95% CI 12.59-23.57)]. The improvement in viability was higher in islets co-cultured in indirect or mixed contact with MSCs than in direct physical contact (P <0.001). Moreover, the mean of insulin stimulation index (ISI) was higher in islets from co-culture condition compared with islet cultured alone [WMD = 0.83 (95% CI 0.54-1.13)], independently of contact system. Results from the studies that were analyzed only qualitatively are in accordance with meta-analysis data. Co-culture of islets with MSCs has the potential for protecting islets from injury during culture period. Moreover, culture time appears to influence the beneficial effect of different methods of co-culture on viability and function of islets.


Asunto(s)
Técnicas de Cocultivo , Insulina/metabolismo , Islotes Pancreáticos/citología , Células Madre Mesenquimatosas/citología , Animales , Humanos , Secreción de Insulina , Islotes Pancreáticos/metabolismo
8.
J Biomed Mater Res A ; 105(5): 1333-1345, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28120428

RESUMEN

Engineering neural tissue by combining biodegradable materials, cells and growth factors is a promising strategy for the treatment of central and peripheral nervous system injuries. In this study, neural differentiation of mouse embryonic stem cells (mESCs) was investigated in combination with three dimensional (3D) electrospun nanofibers as a substitute for the extracellular matrix (ECM). Nano/microfibrous poly(lactic-co-glycolic acid) (PLGA) 3D scaffolds were fabricated through electrospinning and characterized. The scaffolds consisted of either a randomly oriented or an aligned structure of PLGA fibers. The mESCs were induced to differentiate into neuronal lineage and the effect of the polymer and fiber orientation on cell survival, morphology and differentiation efficiency was studied. The neural progenitors derived from the mESCs could survive and migrate onto the fibrous scaffolds. Aligned fibers provided more contact guidance with the neurites preferentially extending along the long axis of fiber. The mESCs differentiated into neural lineages expressing neural markers as seen by the immunocytochemistry. The nestin and beta3-tubulin expression was enhanced on the PLGA aligned fibers in comparison with the other groups, as seen by the quantitative analysis. Taken together, a combination of electrospun fiber scaffolds and mESC derived neural progenitor cells could provide valuable information about the effects of topology on neural differentiation and axonal regeneration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1333-1345, 2017.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Ácido Láctico , Células Madre Embrionarias de Ratones/metabolismo , Nanofibras/química , Células-Madre Neurales/metabolismo , Ácido Poliglicólico , Andamios del Tejido/química , Animales , Antígenos de Diferenciación/biosíntesis , Ácido Láctico/química , Ácido Láctico/farmacología , Ratones , Células Madre Embrionarias de Ratones/citología , Células-Madre Neurales/citología , Ácido Poliglicólico/química , Ácido Poliglicólico/farmacología , Copolímero de Ácido Poliláctico-Ácido Poliglicólico
9.
Drug Discov Today ; 21(8): 1243-56, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27155458

RESUMEN

Whereas highly porous scaffolds composed of electrospun nanofibers can mimick major features of the extracellular matrix in tissue engineering, they lack the ability to incorporate and release biocompounds (drugs, growth factors) safely in a controlled way. Here, electrospun core-shell fibers (core made from water and aqueous solutions of hydrophilic polymers and the shell from materials with well-defined release mechanisms) offer unique advantages in comparison with those that have helped make porous nanofibrillar scaffolds highly successful in tissue engineering. This review considers the preparation and biofunctionalization of such core-shell fibers as well as applications in various areas, including neural, vascular, cardiac, cartilage and bone tissue engineering, and touches on the topic of clinical trials.


Asunto(s)
Sistemas de Liberación de Medicamentos , Nanofibras , Ingeniería de Tejidos , Animales , Humanos , Nanotecnología , Tecnología Farmacéutica
10.
Alcohol ; 49(7): 665-74, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26314629

RESUMEN

Ethanol exposure to offspring during pregnancy and lactation leads to developmental disorders, including central nervous system dysfunction. In the present work, we have studied the effect of chronic ethanol exposure during pregnancy and lactation on the phosphorylating system associated with the astrocytic and neuronal intermediate filament (IF) proteins: glial fibrillary acidic protein (GFAP), and neurofilament (NF) subunits of low, medium, and high molecular weight (NFL, NFM, and NFH, respectively) in 9- and 21-day-old pups. Female rats were fed with 20% ethanol in their drinking water during pregnancy and lactation. The homeostasis of the IF phosphorylation was not altered in the cerebral cortex, cerebellum, or hippocampus of 9-day-old pups. However, GFAP, NFL, and NFM were hyperphosphorylated in the hippocampus of 21-day-old pups. PKA had been activated in the hippocampus, and Ser55 in the N-terminal region of NFL was hyperphosphorylated. In addition, JNK/MAPK was activated and KSP repeats in the C-terminal region of NFM were hyperphosphorylated in the hippocampus of 21-day-old pups. Decreased NFH immunocontent but an unaltered total NFH/phosphoNFH ratio suggested altered stoichiometry of NFs in the hippocampus of ethanol-exposed 21-day-old pups. In contrast to the high susceptibility of hippocampal cytoskeleton in developing rats, the homeostasis of the cytoskeleton of ethanol-fed adult females was not altered. Disruption of the cytoskeletal homeostasis in neural cells supports the view that regions of the brain are differentially vulnerable to alcohol insult during pregnancy and lactation, suggesting that modulation of JNK/MAPK and PKA signaling cascades target the hippocampal cytoskeleton in a window of vulnerability in 21-day-old pups. Our findings are relevant, since disruption of the cytoskeleton in immature hippocampus could contribute to later hippocampal damage associated with ethanol toxicity.


Asunto(s)
Depresores del Sistema Nervioso Central/toxicidad , Citoesqueleto/efectos de los fármacos , Etanol/toxicidad , Hipocampo/efectos de los fármacos , Lactancia , Animales , Animales Recién Nacidos , Peso Corporal/efectos de los fármacos , Proteínas Quinasas Dependientes de AMP Cíclico/efectos de los fármacos , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Ingestión de Energía/efectos de los fármacos , Femenino , Proteína Ácida Fibrilar de la Glía/metabolismo , Hipocampo/embriología , Homeostasis , Filamentos Intermedios/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteínas de Neurofilamentos/metabolismo , Fosforilación , Embarazo , Ratas , Ratas Wistar
11.
Metab Brain Dis ; 28(3): 429-38, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23378107

RESUMEN

Carbonyl compounds such as methylglyoxal (MGO) seem to play an important role in complications resulting from diabetes mellitus, in aging and neurodegenerative disorders. In this study, we are showing, that MGO is able to suppress cell viability and induce apoptosis in the cerebral cortex and hippocampus of neonatal rats ex-vivo. These effects are partially related with ROS production, evaluated by DCFH-DA assay. Coincubation of MGO and reduced glutathione (GSH) or Trolox (vitamin E) totally prevented ROS production but only partially prevented the MGO-induced decreased cell viability in the two brain structures, as evaluated by the MTT assay. Otherwise, L-NAME, a nitric oxide (NO) inhibitor, partially prevented ROS production in the two structures but partially prevented cytotoxicity in the hippocampus. Pharmacological inhibition of Erk, has totally attenuated MGO-induced ROS production and cytotoxicity, suggesting that MEK/Erk pathway could be upstream of ROS generation and cell survival. Otherwise, p38MAPK and JNK failed to prevent ROS generation but induced decreased cell survival consistent with ROS-independent mechanisms. We can propose that Erk, p38MAPK and JNK are involved in the cytotoxicity induced by MGO through different signaling pathways. While Erk could be an upstream effector of ROS generation, p38MAPK and JNK seem to be associated with ROS-independent cytotoxicity in neonatal rat brain. The cytotoxic damage progressed to apoptotic cell death at MGO concentration higher than those described for adult brain, suggesting that the neonatal brain is resistant to MGO-induced cell death. The consequences of MGO-induced brain damage early in life, remains to be clarified. However, it is feasible that high MGO levels during cortical and hippocampal development could be, at least in part, responsible for the impairment of cognitive functions in adulthood.


Asunto(s)
Encéfalo/patología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Piruvaldehído/toxicidad , Animales , Animales Recién Nacidos , Anexina A5/metabolismo , Antioxidantes/farmacología , Western Blotting , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Supervivencia Celular/efectos de los fármacos , Colorantes , Colorantes Fluorescentes , Técnicas In Vitro , L-Lactato Deshidrogenasa/metabolismo , MAP Quinasa Quinasa 4/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Piruvaldehído/antagonistas & inhibidores , Piruvaldehído/metabolismo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Sales de Tetrazolio , Tiazoles , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
12.
Neurotoxicology ; 33(5): 1106-16, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22705628

RESUMEN

In the present report we examined the effect of maternal exposure to diphenyl ditelluride (PhTe)(2) (0.01 mg/kg body weight) during the first 14 days of lactational period on the activity of some protein kinases targeting the cytoskeleton of striatum and cerebellum of their offspring. We analyzed the phosphorylating system associated with glial fibrillary acidic protein (GFAP), and neurofilament of low, medium and high molecular weight (NF-L, NF-M and NF-H, respectively) of pups on PND 15, 21, 30 and 45. We found that (PhTe)(2) induced hyperphosphorylation of all the proteins studied on PND 15 and 21, recovering control values on PND 30 and 45. The immunocontent of GFAP, NF-L, NF-M and NF-H in the cerebellum of 15-day-old pups was increased. Western blot assays showed activation/phosphorylation of Erk1/2 on PND 21 and activation/phosphorylation of JNK on PND 15. Otherwise, p38MAPK was not activated in the striatum of (PhTe)(2) exposed pups. On the other hand, the cerebellum of pups exposed to (PhTe)(2) presented activated/phosphorylated Erk1/2 on PND 15 and 21 as well as activated/phosphorylated p38MAPK on PND 21, while JNK was not activated. Western blot assays showed that both in the striatum and in the cerebellum of (PhTe)(2) exposed pups, the immunocontent of the catalytic subunit of PKA (PKAcα) was increased on PND 15. Western blot showed that the phosphorylation level of NF-L Ser55 and NF-M/NF-H KSP repeats was increased in the striatum and cerebellum of both 15- and 21-day-old pups exposed to (PhTe)(2). Diphenyl diselenide (PhSe)(2), the selenium analog of (PhTe)(2), prevented (PhTe)(2)-induced hyperphosphorylation of striatal intermediate filament (IF) proteins but it failed to prevent the action of (PhTe)(2) in cerebellum. Western blot assay showed that the (PhSe)(2) prevented activation/phosphorylation of Erk1/2, JNK and PKAcα but did not prevent the stimulatory effect of (PhTe)(2) on p38MAPK in cerebellum at PND 21. In conclusion, this study demonstrated that dam exposure to low doses of (PhTe)(2) can alter cellular signaling targeting the cytoskeleton of striatum and cerebellum in the offspring in a spatiotemporal manner, which can be related to the neurotoxic effects of (PhTe)(2).


Asunto(s)
Derivados del Benceno/toxicidad , Cerebelo/citología , Cuerpo Estriado/citología , Citoesqueleto/metabolismo , Homeostasis/efectos de los fármacos , Neuronas/efectos de los fármacos , Compuestos Organometálicos/toxicidad , Efectos Tardíos de la Exposición Prenatal/patología , Factores de Edad , Análisis de Varianza , Animales , Animales Recién Nacidos , Peso Corporal/efectos de los fármacos , Femenino , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Proteína Ácida Fibrilar de la Glía/metabolismo , Técnicas In Vitro , Proteínas de Neurofilamentos/metabolismo , Neuronas/metabolismo , Fosfatos/farmacocinética , Isótopos de Fósforo/farmacocinética , Embarazo , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Factores de Tiempo
13.
Exp Neurol ; 233(1): 391-9, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22116044

RESUMEN

The studies of signaling mechanisms involved in the disruption of the cytoskeleton homeostasis were performed in a model of quinolinic acid (QUIN) neurotoxicity in vitro. This investigation focused on the phosphorylation level of intermediate filament (IF) subunits of astrocytes (glial fibrillary acidic protein - GFAP) and neurons (low, medium and high molecular weight neurofilament subunits - NFL, NFM and NFH, respectively). The activity of the phosphorylating system associated with the IFs was investigated in striatal slices of rat exposed to QUIN or treated simultaneously with QUIN plus glutamate receptor antagonists, calcium channel blockers or kinase inhibitors. Results showed that in astrocytes, the action of 100 µM QUIN was mainly due to increased Ca(2+) influx through NMDA and L-type voltage-dependent Ca(2+) channels (L-VDCC). In neuronal cells QUIN acted through metabotropic glutamate receptor (mGluR) activation and influx of Ca(2+) through NMDA receptors and L-VDCC, as well as Ca(2+) release from intracellular stores. These mechanisms then set off a cascade of events including activation of PKA, PKCaMII and PKC, which phosphorylate head domain sites on GFAP and NFL. Also, Cdk5 was activated downstream of mGluR5, phosphorylating the KSP repeats on NFM and NFH. mGluR1 was upstream of phospholipase C (PLC) which, in turn, produced diacylglycerol (DAG) and inositol 3,4,5 triphosphate (IP3). DAG is important to activate PKC and phosphorylate NFL, while IP(3) contributed to Ca(2+) release from internal stores promoting hyperphosphorylation of KSP repeats on the tail domain of NFM and NFH. The present study supports the concept of glutamate and Ca(2+) contribution in excitotoxic neuronal damage provoked by QUIN associated to dysfunction of the cytoskeleton homeostasis and highlights the differential signaling mechanisms elicited in striatal astrocytes and neurons.


Asunto(s)
Astrocitos/citología , Cuerpo Estriado/citología , Citoesqueleto/efectos de los fármacos , Citoesqueleto/metabolismo , Neuronas/citología , Ácido Quinolínico/farmacología , Transducción de Señal/efectos de los fármacos , Análisis de Varianza , Animales , Astrocitos/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cuerpo Estriado/efectos de los fármacos , Interacciones Farmacológicas , Inhibidores Enzimáticos/farmacología , Técnicas In Vitro , Proteínas del Tejido Nervioso/metabolismo , Neuronas/efectos de los fármacos , Ratas , Ratas Wistar
14.
Arch Toxicol ; 86(2): 217-30, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21863293

RESUMEN

We studied the effect of different concentrations of diphenyl ditelluride (PhTe)(2) on the in vitro phosphorylation of glial fibrillary acidic protein (GFAP) and neurofilament (NF) subunits from cerebral cortex and hippocampus of rats during development. (PhTe)(2)-induced hypophosphorylation of GFAP and NF subunits only in cerebral cortex of 9- and 15-day-old animals but not in hippocampus. Hypophosphorylation was dependent on ionotropic glutamate receptors, as demonstrated by the specific inhibitors 10 µM DL-AP5 and 50 µM MK801, 100 µM CNQX and 100 µM DNQX. Also, 10 µM verapamil and 10 µM nifedipine, two L-voltage-dependent Ca(2+) channels (L-VDCC) blockers; 50 µM dantrolene, a ryanodine channel blocker, and the intracellular Ca(2+) chelator Bapta-AM (50 µM) totally prevented this effect. Results obtained with 0.2 µM calyculin A (PP1 and PP2A inhibitor), 1 µM Fostriecin a potent protein phosphatase 2A (PP2A) inhibitor, 100 µM FK-506 or 100 µM cyclosporine A, specific protein phosphatase 2B inhibitors, pointed to PP1 as the protein phosphatase directly involved in the hypophosphorylating effect of (PhTe)(2). Finally, we examined the activity of DARPP-32, an important endogenous Ca(2+)-mediated inhibitor of PP1 activity. Western blot assay using anti-DARPP-32, anti-pThr34DARPP-32, and anti-pThr75DARPP-32 antibodies showed a decreased phosphorylation level of the inhibitor at Thr34, compatible with inactivation of protein kinase A (PKA) by pThr75 DARPP-32. Decreased cAMP and catalytic subunit of PKA support that (PhTe)(2) acted on neuron and astrocyte cytoskeletal proteins through PKA-mediated inactivation of DARPP-32, promoting PP1 release and hypophosphorylation of IF proteins of those neural cells. Moreover, in the presence of Bapta, the level of the PKA catalytic subunit was not decreased by (PhTe)(2), suggesting that intracellular Ca(2+) levels could be upstream the signaling pathway elicited by this neurotoxicant and targeting the cytoskeleton.


Asunto(s)
Derivados del Benceno/farmacología , Corteza Cerebral/efectos de los fármacos , Fosfoproteína 32 Regulada por Dopamina y AMPc/metabolismo , Filamentos Intermedios/efectos de los fármacos , Compuestos Organometálicos/farmacología , Animales , Corteza Cerebral/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Citoesqueleto/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Filamentos Intermedios/metabolismo , Fosforilación/efectos de los fármacos , Proteína Fosfatasa 1/metabolismo , Ratas , Transducción de Señal
15.
Chem Res Toxicol ; 24(10): 1754-64, 2011 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-21879721

RESUMEN

In the present report, we showed that diphenyl ditelluride (PhTe)(2) induced in vitro hyperphosphorylation of glial fibrillary acidic protein (GFAP), vimentin and neurofilament (NF) subunits in hippocampus of 21 day-old rats. Hyperphosphorylation was dependent on L-voltage dependent Ca(2+) channels (L-VDCC), N-methyl-d-aspartate (NMDA) and metabotropic glutamate receptors, as demonstrated by the specific inhibitors verapamil, DL-AP5 and MCPG, respectively. Also, dantrolene, a ryanodine channel blocker, EGTA and Bapta-AM, extra and intracellular Ca(2+) chelators respectively, totally prevented this effect. Activation of metabotropic glutamate receptors by (PhTe)(2) upregulates phospholipase C (PLC), producing inositol 1, 4, 5-trisphosphate (IP(3)) and diacylglycerol (DAG). Therefore, high Ca(2+) levels and DAG directly activate Ca(2+)/calmodulin-dependent protein kinase (PKCaMII) and protein kinase C (PCK), resulting in the hyperphosphorylation of Ser-57 in the carboxyl-terminal tail domain of the low molecular weight NF subunit (NF-L). Also, the activation of Erk1/2, and p38MAPK resulted in hyperphosphorylation of KSP repeats of the medium molecular weight NF subunit (NF-M). It is noteworthy that PKCaMII and PKC inhibitors prevented (PhTe)(2)-induced Erk1/2MAPK and p38MAPK activation as well as hyperphosphorylation of KSP repeats on NF-M, suggesting that PKCaMII and PKC could be upstream of this activation. Taken together, our results highlight the role of Ca(2+) as a mediator of the (PhTe)(2)-elicited signaling targeting specific phosphorylation sites on IF proteins of neural cells of rat hippocampus. Interestingly, this action shows a significant cross-talk among signaling pathways elicited by (PhTe)(2), connecting glutamate metabotropic cascade with activation of Ca(2+) channels. The extensively phosphorylated amino- and carboxyl- terminal sites could explain, at least in part, the neural dysfunction associated with (PhTe)(2) exposure.


Asunto(s)
Derivados del Benceno/toxicidad , Calcio/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Hipocampo/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteínas de Neurofilamentos/metabolismo , Compuestos Organometálicos/toxicidad , Vimentina/metabolismo , Animales , Bencilaminas/farmacología , Western Blotting , Canales de Calcio Tipo L/metabolismo , Corteza Cerebral/efectos de los fármacos , Citoesqueleto/efectos de los fármacos , Citoesqueleto/metabolismo , Electroforesis en Gel de Poliacrilamida , Hipocampo/metabolismo , Técnicas In Vitro , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosforilación/efectos de los fármacos , Proteína Quinasa C/antagonistas & inhibidores , Ratas , Ratas Wistar , Estaurosporina/farmacología , Sulfonamidas/farmacología
16.
Toxicol In Vitro ; 25(1): 28-36, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20837132

RESUMEN

Central nervous system dysfunctions are among the most significant effects of exposure to ethanol and the glial cells that play an important role in maintaining neuronal function, are extremely involved with these effects. The actin cytoskeleton plays a crucial role in a wide variety of cellular functions, especially when there is some injury. Therefore the aim of the present study was to analyze the short-term effects of ethanol (50, 100 and 200 mM) on the cytoskeleton of C6 glioma cells. Here we report that acute ethanol exposure profoundly disrupts the actin cytoskeleton in C6 cells decreasing stress fiber formation and downregulating RhoA and vinculin immunocontent. In contrast, microtubule and GFAP networks were not altered. We further demonstrate that anti-oxidants prevent ethanol-induced actin alterations, suggesting that the actions of ethanol on the actin cytoskeleton are related with generation of reactive oxygen species (ROS) in these cells. Our results show that ethanol at concentrations described to be toxic to the central nervous system was able to target the cytoskeleton of C6 cells and this effect could be related with increased ROS generation. Therefore, we propose that the dynamic restructuring of the cytoskeleton of glial cells might contribute to the response to the injury provoked by binge-like ethanol exposure in brain.


Asunto(s)
Actinas/metabolismo , Fármacos del Sistema Nervioso Central/toxicidad , Citoesqueleto/efectos de los fármacos , Etanol/toxicidad , Proteínas del Tejido Nervioso/metabolismo , Neuroglía/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Actinas/genética , Animales , Antioxidantes/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Fármacos del Sistema Nervioso Central/antagonistas & inhibidores , Citoesqueleto/metabolismo , Citoesqueleto/ultraestructura , Regulación hacia Abajo/efectos de los fármacos , Etanol/antagonistas & inhibidores , Neuroglía/metabolismo , Neuroglía/ultraestructura , Concentración Osmolar , Estrés Oxidativo/efectos de los fármacos , ARN Mensajero/metabolismo , Ratas , Fibras de Estrés/efectos de los fármacos , Fibras de Estrés/metabolismo , Factores de Tiempo , Vinculina/metabolismo , Proteína de Unión al GTP rhoA/metabolismo
17.
Rev Bras Ginecol Obstet ; 32(7): 334-9, 2010 Jul.
Artículo en Portugués | MEDLINE | ID: mdl-21152842

RESUMEN

PURPOSE: To evaluate clinical and laboratory characteristics of first-degree male relatives of patients with a confirmed diagnosis of polycystic ovary syndrome (PCOS) and to compare the findings with a control group with no family history of PCOS. METHODS: We randomly selected 28 male individuals aged 18 to 65 years who were first-degree relatives of women diagnosed with PCOS and 28 controls matched for age, waist and body mass index (BMI). RESULTS: Men with 1st degree kinship with women with PCOS had higher levels of triglycerides (189.6±103.1 versus 99.4±37.1, p<0.0001), Homeostasis Model Assessment (HOMA-IR) (3.5±9.1 versus 1.0±1.0, p=0.0077) and glucose (130.1±81.7 versus 89.5±7.8, p=0.005), and lower levels of sex hormone binding globulin (SHBG) (23.8±13.8 versus 31.1±9.1, p=0.003). SHBG levels correlated independently with triglyceride levels. These individuals also had more clinical signs of hyperandrogenism. CONCLUSIONS: Male individuals who are first-degree relatives of patients with PCOS have a higher degree of dyslipidemia and insulin resistance, lower levels of SHBG, and more evident clinical signs of hyperandrogenism. These findings suggest that insulin resistance may be of hereditary origin in individuals with a family history of PCOS regardless of anthropometric parameters.


Asunto(s)
Índice de Masa Corporal , Hiperandrogenismo/sangre , Síndrome del Ovario Poliquístico , Circunferencia de la Cintura , Relación Cintura-Cadera , Adolescente , Adulto , Anciano , Femenino , Humanos , Hiperandrogenismo/genética , Masculino , Persona de Mediana Edad , Síndrome del Ovario Poliquístico/genética , Circunferencia de la Cintura/genética , Adulto Joven
18.
Rev. bras. ginecol. obstet ; 32(7): 334-339, jul. 2010. tab
Artículo en Portugués | LILACS | ID: lil-567966

RESUMEN

OBJETIVO: avaliar as características clínicas e laboratoriais de parentes de primeiro grau do sexo masculino de pacientes com diagnóstico confirmado de síndrome de ovários policísticos (SOP) e comparar os achados com um grupo controle sem história familiar de SOP. MÉTODOS: foram selecionados aleatoriamente 28 homens com idade entre 18 e 65 anos que possuíam parentesco de primeiro grau com mulheres diagnosticadas com SOP e 28 controles pareados por idade, cintura e índice de massa corporal (IMC). RESULTADOS: homens com parentesco de 1º grau com mulheres com SOP comparados ao Grupo Controle apresentaram níveis mais elevados de triglicerídeos (189,6±103,1 versus 99,4±37,1; p<0,0001), HOMA-IR (Homeostase Model Assesment) (3,5±9,1 versus 1,0±1,0; p=0,0077) e glicemia (130,1±81,7 versus 89,5±7,8; p=0,005), além de menores níveis da globulina ligadora de hormônios sexuais (SHBG) (23,8±13,8 versus 31,1±9,1; p=0,003). Os níveis de SHBG se correlacionaram independentemente com os níveis de triglicérides. Os parentes de 1º grau também apresentavam mais sinais clínicos de hiperandrogenismo. CONCLUSÕES: parentes de primeiro grau do sexo masculino das pacientes com SOP apresentam maior grau de dislipidemia e de resistência à insulina, além de níveis mais baixos de SHBG com mais sinais clínicos de hiperandrogenismo. Esses achados sugerem que a resistência à insulina pode ter origem hereditária em indivíduos com história familiar de SOP, independentemente de parâmetros antropométricos.


PURPOSE: to evaluate clinical and laboratory characteristics of first-degree male relatives of patients with a confirmed diagnosis of polycystic ovary syndrome (PCOS) and to compare the findings with a control group with no family history of PCOS. METHODS: we randomly selected 28 male individuals aged 18 to 65 years who were first-degree relatives of women diagnosed with PCOS and 28 controls matched for age, waist and body mass index (BMI). RESULTS: men with 1st degree kinship with women with PCOS had higher levels of triglycerides (189.6±103.1 versus 99.4±37.1, p<0.0001), Homeostasis Model Assessment (HOMA-IR) (3.5±9.1 versus 1.0±1.0, p=0.0077) and glucose (130.1±81.7 versus 89.5±7.8, p=0.005), and lower levels of sex hormone binding globulin (SHBG) (23.8±13.8 versus 31.1±9.1, p=0.003). SHBG levels correlated independently with triglyceride levels. These individuals also had more clinical signs of hyperandrogenism. CONCLUSIONS: male individuals who are first-degree relatives of patients with PCOS have a higher degree of dyslipidemia and insulin resistance, lower levels of SHBG, and more evident clinical signs of hyperandrogenism. These findings suggest that insulin resistance may be of hereditary origin in individuals with a family history of PCOS regardless of anthropometric parameters.


Asunto(s)
Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Índice de Masa Corporal , Hiperandrogenismo/sangre , Síndrome del Ovario Poliquístico , Circunferencia de la Cintura , Relación Cintura-Cadera , Hiperandrogenismo/genética , Síndrome del Ovario Poliquístico/genética , Circunferencia de la Cintura/genética
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