RESUMEN

Mercury (Hg) is an environmental contaminant that poses great risk to human health. However, it is still widely used in artisanal gold-mining enterprises around the world, especially in developing countries. Methylmercury (MeHg) is produced environmentally by biomethylation of inorganic Hg present in water sediments, leading to its subsequent accumulation in the aquatic food chain. Due to its high metabolic rate, the Central Nervous System (CNS) is one of the main targets of MeHg. In the present study, we investigate the impact of chronic MeHg intoxication on NADPH diaphorase (NADPH-d) activity and astrocyte mobilization in the visual cortex of the rat. After 60 days of MeHg administration by oral gavage (0.04 mg/kg/day), tissue samples containing the visual cortex were submitted to measurements of Hg levels, NADPH-d activity, and GFAP immunohistochemistry for identification of astrocytes. MeHg intoxication was associated with increased Hg deposits and with reduced NADPH-d neuropil reactivity in the visual cortex. A morphometric analysis suggested that NADPH-d-positive neurons were mostly spared from MeHg harmful action and intoxicated animals had astrocytic activation similar to the control group. The decrease in NADPH-d neuropil reactivity may be due to the negative effect of chronic MeHg poisoning on both the synthesis and transport of this enzyme in afferent pathways to the visual cortex. The relative resistance of NADPH-d-reactive neurons to chronic MeHg intoxication may be associated with peculiarities in cell metabolism or to a protective role of nitric oxide, safeguarding those neurons from Hg deleterious effects.

Asunto(s)

Astrocitos/efectos de los fármacos , Contaminantes Ambientales/toxicidad , Compuestos de Metilmercurio/toxicidad , NADPH Deshidrogenasa/metabolismo , Neuronas/efectos de los fármacos , Corteza Visual/efectos de los fármacos , Animales , Astrocitos/enzimología , Conducta Animal/efectos de los fármacos , Contaminantes Ambientales/metabolismo , Oro , Humanos , Masculino , Compuestos de Metilmercurio/metabolismo , Minería , Neuronas/enzimología , Ratas , Ratas Wistar , Corteza Visual/enzimología , Corteza Visual/patología

RESUMEN

Neuronal signaling is known to be required for salivary gland development, with parasympathetic nerves interacting with the surrounding tissues from early stages to maintain a progenitor cell population and control morphogenesis. In contrast, postganglionic sympathetic nerves arrive late in salivary gland development to perform a secretory function; however, no previous report has shown their role during development. Here, we show that a subset of neuronal cells within the parasympathetic submandibular ganglion (PSG) express the catecholaminergic marker tyrosine hydroxylase (TH) in developing murine and human submandibular glands. This sympathetic phenotype coincided with the expression of transcription factor Hand2 within the PSG from the bud stage (E12.5) of mouse embryonic salivary gland development. Hand2 was previously associated with the decision of neural crest cells to become sympathetic in other systems, suggesting a role in controlling neuronal fate in the salivary gland. The PSG therefore provides a population of TH-expressing neurons prior to the arrival of the postganglionic sympathetic axons from the superior cervical ganglion at E15.5. In culture, in the absence of nerves from the superior cervical ganglion, these PSG-derived TH neurons were clearly evident forming a network around the gland. Chemical ablation of dopamine receptors in explant culture with the neurotoxin 6-hydroxydopamine at early stages of gland development resulted in specific loss of the TH-positive neurons from the PSG, and subsequent branching was inhibited. Taken altogether, these results highlight for the first time the detailed developmental time course of TH-expressing neurons during murine salivary gland development and suggest a role for these neurons in branching morphogenesis.

Asunto(s)

Neuronas/citología , Glándula Submandibular/embriología , Sistema Nervioso Simpático/citología , Tirosina 3-Monooxigenasa , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/fisiología , Humanos , Ratones , Neuronas/enzimología

RESUMEN

Phosphodiesterase-5 inhibitors (PDE5Is) have been shown to modulate cell death/cell survival in different in vivo and in vitro models of disease by activating many signaling pathways. This review aimed at elucidating how PDE5Is can inhibit apoptosis. In this study, we describe many signaling pathways involved with the mechanism of action of PDE5Is that ultimately inhibit apoptosis and thus promote cell survival.

Asunto(s)

Apoptosis/efectos de los fármacos , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 5/genética , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Neuronas/efectos de los fármacos , Inhibidores de Fosfodiesterasa 5/farmacología , Citrato de Sildenafil/farmacología , Animales , Apoptosis/genética , Autofagia/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , GMP Cíclico/agonistas , GMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de GMP Cíclico/genética , Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 5/metabolismo , Encefalomielitis Autoinmune Experimental/enzimología , Encefalomielitis Autoinmune Experimental/genética , Encefalomielitis Autoinmune Experimental/patología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Regulación de la Expresión Génica , Humanos , Ratones , Neuronas/enzimología , Neuronas/patología , Transducción de Señal , Médula Espinal/efectos de los fármacos , Médula Espinal/enzimología , Médula Espinal/patología

RESUMEN

Recent studies have shown that probucol (PB), a hipocholesterolemic agent with antioxidant and anti-inflammatory properties, presents neuroprotective properties. On the other hand, adverse effects have limited PB's clinical application. Thus, the search for PB derivatives with no or less adverse effects has been a topic of research. In this study, we present a novel organoselenium PB derivative (RC513) and investigate its potential protective activity in an in vitro experimental model of oxidative toxicity induced by tert-butyl hydroperoxide (tBuOOH) in HT22 neuronal cells, as well as exploit potential protective mechanisms. tBuOOH exposure caused a significant decrease in the cell viability, which was preceded by (i) increased reactive species generation and (ii) decreased mitochondrial maximum oxygen consumption rate. RC513 pretreatment (48 h) significantly prevented the tBuOOH-induced decrease of cell viability, RS generation, and mitochondrial dysfunction. Of note, RC513 significantly increased glutathione peroxidase (GPx) activity and mRNA expression of GPx1, a key enzyme involved in peroxide detoxification. The use of mercaptosuccinic acid, an inhibitor of GPx, significantly decreased the protective activity of RC513 against tBuOOH-induced cytotoxicity in HT22 cells, highlighting the importance of GPx upregulation in the observed protection. In summary, the results showed a significant protective activity of a novel PB derivative against tBuOOH-induced oxidative stress and mitochondrial dysfunction, which was related to the upregulation of GPx. Our results point to RC513 as a promising neuroprotective molecule, even though studies concerning potential beneficial effects and safety aspects of RC513 under in vivo conditions are well warranted.

Asunto(s)

Diseño de Fármacos , Glutatión Peroxidasa/metabolismo , Neuronas/enzimología , Fármacos Neuroprotectores/síntesis química , Fármacos Neuroprotectores/farmacología , Probucol/síntesis química , Probucol/farmacología , Regulación hacia Arriba , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Glutatión Peroxidasa/genética , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Neuronas/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Compuestos de Sulfhidrilo/metabolismo , Tiomalatos , Factores de Tiempo , terc-Butilhidroperóxido , Glutatión Peroxidasa GPX1

RESUMEN

Many studies have shown that a maternal low-protein diet increases the susceptibility of offspring to cardiovascular disease in later-life. Moreover, a lower incidence of cardiovascular disease in females than in males is understood to be largely due to the protective effect of high levels of estrogens throughout a woman's reproductive life. However, to our knowledge, the role of estradiol in moderating the later-life susceptibility of offspring of nutrient-deprived mothers to cardiovascular disease is not fully understood. The present study is aimed at investigating whether oxidative stress in the brainstem caused by a maternal low-protein diet administered during a critical period of fetal/neonatal brain development (i.e during gestation and lactation) is affected by estradiol levels. Female Wistar rat offspring were divided into four groups according to their mothers' diets and to the serum estradiol levels of the offspring at the time of testing: (1) 22 days of age/control diet: (2) 22 days of age/low-protein diet; (3) 122 days of age/control diet: (4) 122 days of age/low-protein diet. Undernutrition in the context of low serum estradiol compared to undernutrition in a higher estradiol context resulted in increased levels of oxidative stress biomarkers and a reduction in enzymatic and non-enzymatic antioxidant defenses. Total global oxy-score showed oxidative damage in 22-day-old rats whose mothers had received a low-protein diet. In the 122-day-old group, we observed a decrease in oxidative stress biomarkers, increased enzymatic antioxidant activity, and a positive oxy-score when compared to control. We conclude from these results that following a protein deficiency in the maternal diet during early development of the offspring, estrogens present at high levels at reproductive age may confer resistance to the oxidative damage in the brainstem that is very apparent in pre-pubertal rats.

Asunto(s)

Tronco Encefálico/metabolismo , Dieta con Restricción de Proteínas/efectos adversos , Desnutrición/metabolismo , Fenómenos Fisiologicos Nutricionales Maternos , Neuronas/metabolismo , Neuroprotección , Estrés Oxidativo , Animales , Animales Recién Nacidos , Biomarcadores/sangre , Biomarcadores/metabolismo , Tronco Encefálico/enzimología , Estradiol/sangre , Femenino , Glutatión/metabolismo , Glutatión Transferasa/metabolismo , Lactancia , Peroxidación de Lípido , Desnutrición/sangre , Desnutrición/etiología , Proteínas del Tejido Nervioso/metabolismo , Neuronas/enzimología , Oxidación-Reducción , Oxidorreductasas/metabolismo , Embarazo , Carbonilación Proteica , Ratas Wistar

RESUMEN

The Wistar Audiogenic Rat (WAR) is a well-characterized seizure-prone, inbred rodent strain that, when acutely stimulated with high-intensity sounds, develops brainstem-dependent tonic-clonic seizures that can evolve to limbic-like, myoclonic (forebrain) seizures when the acoustic stimuli are presented chronically (audiogenic kindling). In order to investigate possible mechanisms underlying WAR susceptibility to seizures, we evaluated Na,K-ATPase activity, Ca-ATPase activity, Mg-ATPase activity, lipid membrane composition and oxidative stress markers in whole forebrain and whole brainstem samples of naïve WAR, as compared to samples from control Wistar rats. We also evaluated the expression levels of α1 and α3 isoforms of Na,K-ATPase in forebrain samples. We observed increased Na,K-ATPase activity in forebrain samples and increased oxidative stress markers (lipid peroxidation, glutathione peroxidase and superoxide dismutase) in brainstem samples of WAR. The Ca-ATPase activity, Mg-ATPase activity, lipid membrane composition and expression levels of α1 and α3 isoforms of Na,K-ATPase were unaltered. In view of previous data showing that the membrane potentials from naïve WAR's neurons are less negative than that from neurons from Wistar rats, we suggest that Na,K-ATPase increased activity might be involved in a compensatory mechanism necessary to maintain WAR's brains normal activity. Additionally, ongoing oxidative stress in the brainstem could bring Na,K-ATPase activity back to normal levels, which may explain why WAR's present increased susceptibility to seizures triggered by high-intensity sound stimulation.

Asunto(s)

Tronco Encefálico/enzimología , Estrés Oxidativo/fisiología , Prosencéfalo/enzimología , Convulsiones , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Estimulación Acústica/efectos adversos , Adenosina Trifosfatasas/metabolismo , Animales , Tronco Encefálico/patología , Modelos Animales de Enfermedad , Glutatión Peroxidasa/metabolismo , Excitación Neurológica/fisiología , Peroxidación de Lípido , Neuronas/enzimología , Prosencéfalo/patología , Isoformas de Proteínas/metabolismo , Ratas , Ratas Wistar , Convulsiones/etiología , Convulsiones/metabolismo , Convulsiones/patología

RESUMEN

During development sex differences in aromatase expression in limbic regions of mouse brain depend on sex chromosome factors. Genes on the sex chromosomes may affect the hormonal regulation of aromatase expression and this study was undertaken to explore that possibility. Male E15 anterior amygdala neuronal cultures expressed higher levels of aromatase (mRNA and protein) than female cultures. Furthermore, treatment with oestradiol (E2) or dihydrotestosterone (DHT) increased Cyp19a1 expression and aromatase protein levels only in female neuronal cultures. The effect of E2 on aromatase expression was not imitated by oestrogen receptor (ER) α agonist PPT or the GPER agonist G1, but it was fully reproduced by DPN, a specific ligand of ERß. By contrast, the effect of DHT on aromatase expression was not blocked by the anti-androgen flutamide, but completely abrogated by the ERß antagonist PHTPP. Experiments using the four core genotype model showed a sex chromosome effect in ERß expression (XY > XX) and regulation by E2 or DHT (only XX respond) in amygdala neurons. In conclusion, sex chromosome complement governs the hormonal regulation of aromatase expression through activation of ERß in developing mouse brain.

Asunto(s)

Amígdala del Cerebelo/embriología , Amígdala del Cerebelo/enzimología , Aromatasa/biosíntesis , Receptor beta de Estrógeno/metabolismo , Regulación del Desarrollo de la Expresión Génica , Neuronas/enzimología , Cromosomas Sexuales , Animales , Células Cultivadas , Dihidrotestosterona/metabolismo , Estradiol/metabolismo , Femenino , Masculino , Ratones

RESUMEN

The Duchenne Muscular Dystrophy (DMD) is a genetic disorder characterized by the absence of dystrophin protein, causing severe myopathy from increases of oxidative stress. Injuries of intestinal muscle can compromise the myenteric plexus. This study aimed to evaluate the disorders occurred in the muscular layer and in the acetylcholinesterase myenteric neurons (ACHE-r) of ileum of mdx mice, and the effects of supplementation with ascorbic acid (AA) in both components. 30 male mice C57BL/10, and 30 male mice C57BL/10Mdx were separated according to the age and treatment (n=10/group): 30-days-old control group (C30); 30-days-old dystrophic group (D30); 60-days-old control group (C60); 60-days-old dystrophic group (D60); 60-days-old control group supplemented with AA (CS60); and 60-days-old dystrophic group supplemented with AA (DS60). The animals were euthanized and the ileum was collected and processed. Semi-serial sections were stained by Masson's trichrome, and acetylcholinesterase histochemical technique in whole-mounts preparations to identify the myenteric neurons. The muscular layer thickness and the area of smooth muscle of ileum were lower in dystrophic groups, especially in D30 group. The DS60 group showed the muscular layer thickness similar to C60. The density of ACHE-r neurons of myenteric plexus of ileum was lower in D30 animals; however, it was similar in animals of 60-days-old without treatment (C60 and D60) and, higher in DS60. The cell body profile area of ACHE-r neurons was similar in C30-D30 and C60-D60; however, it was higher in DS60. DMD caused damage to the ileum's musculature and myenteric plexus, and the AA prevented the ACHE-r neuronal loss.

Asunto(s)

Acetilcolinesterasa/metabolismo , Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Íleon/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Neuronas/efectos de los fármacos , Animales , Recuento de Células , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Núcleo Celular/patología , Tamaño de la Célula/efectos de los fármacos , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , Citoplasma/patología , Modelos Animales de Enfermedad , Íleon/enzimología , Íleon/patología , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos mdx , Músculo Liso/metabolismo , Músculo Liso/patología , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patología , Plexo Mientérico/efectos de los fármacos , Plexo Mientérico/enzimología , Plexo Mientérico/patología , Neuronas/enzimología , Neuronas/patología , Tamaño de los Órganos

RESUMEN

Thioredoxin (Trx) and glyoxalase (Glo) systems have been suggested to be molecular targets of methylglyoxal (MGO). This highly reactive endogenous compound has been associated with the development of neurodegenerative pathologies and cell death. In the present study, the glutathione (GSH), Trx, and Glo systems were investigated to understand early events (0.5-3 h) that may determine cell fate. It is shown for the first time that MGO treatment induces an increase in glutathione reductase (GR) protein in hippocampal slices (1 h) and HT22 nerve cells (0.5 and 2.5 h). Thioredoxin interacting protein (Txnip), thioredoxin reductase (TrxR), Glo1, and Glo2 were markedly increased (2- to 4-fold) in hippocampal slices and 1.2- to 1.3-fold in HT22 cells. This increase in protein levels in hippocampal slices was followed by a corresponding increase in GR, TrxR, and Glo1 activities, but not in HT22 cells. In these cells, GR and TrxR activities were decreased by MGO. This result is in agreement with the idea that MGO can affect the Trx/TrxR reducing system, and now we show that GR and Txnip can also be affected by MGO. Impairment in the GR or TrxR reducing capacity can impair peroxide removal by glutathione peroxidase and peroxiredoxin, as both peroxidases depend on reduced GSH and Trx, respectively. In this regard, inhibition of GR and TrxR by 2-AAPA or auranofin, respectively, potentiated MGO toxicity in differentiated SH-SY5Y cells. Overall, MGO not only triggers a clear defense response in hippocampal slices and HT22 cells but also impairs the Trx/TrxR and GSH/GR reducing couples in HT22 cells. The increased MGO toxicity caused by inhibition of GR and TrxR with specific inhibitors, or their inhibition by MGO treatment, supports the notion that both reducing systems are relevant molecular targets of MGO.

Asunto(s)

Supervivencia Celular/fisiología , Glutatión Reductasa/metabolismo , Piruvaldehído/toxicidad , Tiorredoxinas/metabolismo , Animales , Línea Celular , Relación Dosis-Respuesta a Droga , Femenino , Glutatión/metabolismo , Hipocampo/enzimología , Humanos , Ratones , Neuronas/enzimología , Neuroprotección/fisiología , Piruvaldehído/metabolismo , Reductasa de Tiorredoxina-Disulfuro/metabolismo , Técnicas de Cultivo de Tejidos

RESUMEN

This study investigated the toxicity of rats exposed to lead acetate (AcPb) during the second phase of brain development (8-12 days postnatal) in hematological and cerebral parameters. Moreover, the preventive effect of zinc chloride (ZnCl2) and N-acetylcysteine (NAC) was investigated. Pups were injected subcutaneously with saline (0.9% NaCl solution), ZnCl2 (27 mg/kg/day), NAC (5 mg/kg/day) or ZnCl2 plus NAC for 5 days (3rd-7th postnatal days), and with saline (0.9% NaCl solution) or AcPb (7 mg/kg/day) in the five subsequent days (8th-12th postnatal days). Animals were sacrificed 21 days after the last AcPb exposure. Pups exposed to AcPb presented inhibition of blood porphobilinogen-synthase (PBG-synthase) activity without changes in hemoglobin content. ZnCl2 pre-exposure partially prevented PBG-synthase inhibition. Regarding neurotoxicity biomarkers, animals exposed to AcPb presented a decrease in cerebrum acetylcholinesterase (AChE) activity and an increase in Pb accumulation in blood and cerebrum. These changes were prevented by pre-treatment with ZnCl2, NAC, and ZnCl2 plus NAC. AcPb exposure caused no alteration in behavioral tasks. In short, results show that AcPb inhibited the activity of two important enzymatic biomarkers up to 21 days after the end of the exposure. Moreover, ZnCl2 and NAC prevented the alterations induced by AcPb.

Asunto(s)

Acetilcisteína/uso terapéutico , Cerebro/efectos de los fármacos , Cloruros/uso terapéutico , Intoxicación del Sistema Nervioso por Plomo/prevención & control , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/uso terapéutico , Compuestos de Zinc/uso terapéutico , Acetilcolinesterasa/metabolismo , Acetilcisteína/administración & dosificación , Animales , Animales Recién Nacidos , Biomarcadores/sangre , Biomarcadores/metabolismo , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Cerebro/enzimología , Cerebro/metabolismo , Cloruros/administración & dosificación , Cloruros/metabolismo , Cloruros/farmacocinética , Quimioterapia Combinada , Contaminantes Ambientales/sangre , Contaminantes Ambientales/metabolismo , Contaminantes Ambientales/toxicidad , Proteínas Ligadas a GPI/antagonistas & inhibidores , Proteínas Ligadas a GPI/metabolismo , Inyecciones Subcutáneas , Plomo/sangre , Plomo/metabolismo , Plomo/toxicidad , Intoxicación del Sistema Nervioso por Plomo/sangre , Intoxicación del Sistema Nervioso por Plomo/metabolismo , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Proteínas del Tejido Nervioso/metabolismo , Neuronas/enzimología , Neuronas/metabolismo , Fármacos Neuroprotectores/administración & dosificación , Fármacos Neuroprotectores/metabolismo , Fármacos Neuroprotectores/farmacocinética , Compuestos Organometálicos/administración & dosificación , Porfobilinógeno Sintasa/antagonistas & inhibidores , Porfobilinógeno Sintasa/sangre , Distribución Aleatoria , Ratas Wistar , Distribución Tisular/efectos de los fármacos , Toxicocinética , Compuestos de Zinc/administración & dosificación , Compuestos de Zinc/metabolismo , Compuestos de Zinc/farmacocinética

RESUMEN

Downhill running-based overtraining model increases the hypothalamic levels of IL-1ß, TNF-α, SOCS3, and pSAPK-JNK. The aim of the present study was to verify the effects of 3 overtraining protocols on the levels of BiP, pIRE-1 (Ser724), pPERK (Thr981), pelF2α (Ser52), ATF-6, GRP-94, caspase 4, caspase 12, pAKT (Ser473), pmTOR (Ser2448), and pAMPK (Thr172) proteins in the mouse hypothalamus. The mice were randomized into the control, overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up), and overtrained by running without inclination (OTR) groups. After the overtraining protocols (i.e., at the end of week 8), hypothalamus was removed and used for immunoblotting. The OTR/down group exhibited increased levels of all of the analyzed endoplasmic reticulum stress markers in the hypothalamus at the end of week 8. The OTR/up and OTR groups exhibited increased levels of BiP, pIRE-1 (Ser724), and pPERK (Thr981) in the hypothalamus at the end of week 8. There were no significant differences in the levels of caspase 4, caspase 12, pAKT (Ser473), pmTOR (Ser2448), and pAMPK (Thr172) between the experimental groups at the end of week 8. In conclusion, the 3 overtraining protocols increased the endoplasmic reticulum stress at the end of week 8.

Asunto(s)

Trastornos de Traumas Acumulados/metabolismo , Estrés del Retículo Endoplásmico , Hipotálamo/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Condicionamiento Físico Animal/efectos adversos , Esfuerzo Físico , Animales , Apoptosis , Biomarcadores/metabolismo , Western Blotting , Trastornos de Traumas Acumulados/etiología , Trastornos de Traumas Acumulados/inmunología , Chaperón BiP del Retículo Endoplásmico , Proteínas de Choque Térmico/metabolismo , Hipotálamo/enzimología , Hipotálamo/inmunología , Masculino , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Neuronas/enzimología , Neuronas/inmunología , Fosforilación , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/metabolismo , Distribución Aleatoria , Respuesta de Proteína Desplegada , eIF-2 Quinasa/metabolismo

RESUMEN

In decapod crustaceans, molting is controlled by the pulsatile release of molt-inhibiting hormone (MIH) from neurosecretory cells in the X-organ/sinus gland (XO/SG) complex in the eyestalk ganglia (ESG). A drop in MIH release triggers molting by activating the molting gland or Y-organ (YO). Post-transcriptional mechanisms ultimately control MIH levels in the hemolymph. Neurotransmitter-mediated electrical activity controls Ca2+-dependent vesicular release of MIH from the SG axon terminals, which may be modulated by nitric oxide (NO). In green shore crab, Carcinus maenas, nitric oxide synthase (NOS) protein and NO are present in the SG. Moreover, C. maenas are refractory to eyestalk ablation (ESA), suggesting other regions of the nervous system secrete sufficient amounts of MIH to prevent molting. By contrast, ESA induces molting in the blackback land crab, Gecarcinus lateralis. Double-label immunofluorescence microscopy and quantitative polymerase chain reaction were used to localize and quantify MIH and NOS proteins and transcripts, respectively, in the ESG, brain, and thoracic ganglion (TG) of C. maenas and G. lateralis. In ESG, MIH- and NOS-immunopositive cells were closely associated in the SG of both species; confocal microscopy showed that NOS was localized in cells adjacent to MIH-positive axon terminals. In brain, MIH-positive cells were located in a small number of cells in the olfactory lobe; no NOS immunofluorescence was detected. In TG, MIH and NOS were localized in cell clusters between the segmental nerves. In G. lateralis, Gl-MIH and Gl-crustacean hyperglycemic hormone (CHH) mRNA levels were ~105-fold higher in ESG than in brain or TG of intermolt animals, indicating that the ESG is the primary source of these neuropeptides. Gl-NOS and Gl-elongation factor (EF2) mRNA levels were also higher in the ESG. Molt stage had little or no effect on CHH, NOS, NOS-interacting protein (NOS-IP), membrane Guanylyl Cyclase-II (GC-II), and NO-independent GC-III expression in the ESG of both species. By contrast, MIH and NO receptor GC-I beta subunit (GC-Iß) transcripts were increased during premolt and postmolt stages in G. lateralis, but not in C. maenas. MIH immunopositive cells in the brain and TG may be a secondary source of MIH; the release of MIH from these sources may contribute to the difference between the two species in response to ESA. The MIH-immunopositive cells in the TG may be the source of an MIH-like factor that mediates molt inhibition by limb bud autotomy. The association of MIH- and NOS-labeled cells in the ESG and TG suggests that NO may modulate MIH release. A model is proposed in which NO-dependent activation of GC-I inhibits Ca2+-dependent fusion of MIH vesicles with the nerve terminal membrane; the resulting decrease in MIH activates the YO and the animal enters premolt.

Asunto(s)

Proteínas de Artrópodos/metabolismo , Braquiuros/fisiología , Sistema Nervioso Central/metabolismo , Regulación del Desarrollo de la Expresión Génica , Hormonas de Invertebrados/metabolismo , Neuronas/metabolismo , Óxido Nítrico Sintasa/metabolismo , Animales , Acuicultura , Proteínas de Artrópodos/genética , Océano Atlántico , Braquiuros/crecimiento & desarrollo , California , Sistema Nervioso Central/citología , Sistema Nervioso Central/enzimología , República Dominicana , Ojo , Ganglios de Invertebrados/citología , Ganglios de Invertebrados/enzimología , Ganglios de Invertebrados/metabolismo , Hormonas de Invertebrados/genética , Masculino , Muda , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuronas/citología , Neuronas/enzimología , Óxido Nítrico Sintasa/genética , Corteza Olfatoria/citología , Corteza Olfatoria/enzimología , Corteza Olfatoria/metabolismo , Especificidad de Órganos , Océano Pacífico , Especificidad de la Especie , Tórax

RESUMEN

Iron is a trace element and a structural part of antioxidant enzymes, and its requirements vary according to age and gender. We hypothesized that iron deficiency (ID) leads to an increase in free radicals which mainly affect the brain, and the severity of damage would therefore be dependent on age and gender. Two groups of Wistar rats were evaluated evolutionarily: 100 rats (50 males; 50 females) with ID diet and 100 rats (50 males; 50 females) with standard diet. Both groups were offspring from mothers who were previously under the same dietary intervention. The ages studied roughly correspond to stages of human development: birth (0 postnatal day "PND" in rats), childhood (21 PND), early adolescence (42 PND), late adolescence (56 PND), and adulthood (70 PND). The following biomarkers in the brain, blood, and liver were analyzed: lipid peroxidation products (LPO), protein carbonyl content and activity of the antioxidant enzymes, superoxide dismutase, catalase, and glutathione peroxidase. It was demonstrated that ID subjects are born with high levels of LPO in the brain and low antioxidant activity, the damage being more severe in males. After birth, antioxidant defense focuses on the central level (brain) in ID females and on the peripheral level (blood and liver) in ID males. In two critical stages of development, birth and late adolescence, antioxidant protection is insufficient to counteract oxidative damage in ID subjects. Moreover, we observed that the variability of results in the literature on oxidative stress and ID comes from gender and age of the subjects under study. With this, we can establish patterns and exact moments to carry out studies or treatments.

Asunto(s)

Envejecimiento , Anemia Ferropénica/metabolismo , Encéfalo/metabolismo , Dieta/efectos adversos , Hígado/metabolismo , Neuronas/metabolismo , Estrés Oxidativo , Anemia Ferropénica/etiología , Anemia Ferropénica/fisiopatología , Anemia Ferropénica/prevención & control , Animales , Biomarcadores/sangre , Biomarcadores/metabolismo , Encéfalo/enzimología , Femenino , Compuestos Ferrosos/uso terapéutico , Hierro de la Dieta/uso terapéutico , Lactancia , Peroxidación de Lípido , Hígado/enzimología , Masculino , Fenómenos Fisiologicos Nutricionales Maternos , Neuronas/enzimología , Oxidorreductasas/metabolismo , Embarazo , Carbonilación Proteica , Distribución Aleatoria , Ratas Wistar , Destete

RESUMEN

OBJECTIVES: Obesity is a metabolic and hormonal disorder with serious social and psychological impacts. There is a close relationship among obesity, neuroendocrine homeostasis and behavioral patterns. However, few data are available in the literature regarding this subject. This study assessed behavior and memory of adult obese rats by monosodium l-glutamate (MSG) neonatal treatment or highly palatable dietary treatment. METHODS: MSG obesity was induced by subcutaneous injections of MSG (4 mg/g) during the first 5 days of life (Ob-MSG); control group (C-MSG), received saline solution equimolar. Both groups were fed with commercial chow. To induce dietary obesity, 21-day-old rats were assigned to two experimental diets: highly palatable diet (Ob-Diet) and control diet (C-Diet) composed of commercial chow. Ninety-day-old animals were submitted to behavioral assessment by the open-field test and short- and long-term memory by the object recognition test. Biometric variables were obtained, the Lee index was calculated and mass of retroperitoneal and perigonadal fat pads was measured. Furthermore, an altered behavioral profile was investigated by quantification of plasmatic corticosterone, expression, and activity of hypothalamic extracellular signal-regulated kinase protein (ERK) 1 and 2. RESULTS: Increased Lee index and fat pads were observed in Ob-MSG and Ob-Diet groups. Ob-MSG presented a higher level of anxiety and impaired long-term memory compared to C-MSG, while there was no difference between Ob-Diet and C-Diet. The Ob-MSG group presented a higher level of plasmatic corticosterone and increased phosphorylation of hypothalamic ERK1 and 2. DISCUSSION: Both treatments induced obesity but only Ob-MSG showed altered behavioral parameters, which is related to increased concentration of corticosterone and hypothalamic ERK1 and 2 activation.

Asunto(s)

Corticosterona/sangre , Modelos Animales de Enfermedad , Hipotálamo/metabolismo , Sistema de Señalización de MAP Quinasas , Consolidación de la Memoria , Neuronas/metabolismo , Obesidad/metabolismo , Animales , Animales Recién Nacidos , Conducta Animal/efectos de los fármacos , Corticosterona/agonistas , Activación Enzimática/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Hipotálamo/enzimología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Consolidación de la Memoria/efectos de los fármacos , Memoria a Largo Plazo/efectos de los fármacos , Memoria a Corto Plazo/efectos de los fármacos , Proteína Quinasa 1 Activada por Mitógenos/química , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/química , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Proteínas del Tejido Nervioso/agonistas , Proteínas del Tejido Nervioso/metabolismo , Neuronas/efectos de los fármacos , Neuronas/enzimología , Obesidad/sangre , Obesidad/inducido químicamente , Fosforilación/efectos de los fármacos , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Distribución Aleatoria , Ratas Wistar , Glutamato de Sodio/toxicidad

RESUMEN

Excitotoxicity is the major component in neuropathological conditions, related to harmful action of imbalanced concentrations of glutamate and its agonists in the nervous tissue, ultimately resulting in cell death. In the present study, we evaluated the effects of an acute striatal lesion induced by a focal N-methyl-D-aspartate (NMDA) microinjection on the morphometry of NADPH diaphorase-reactive neurons (NADPH-d+ ), a subset of cells which release nitric oxide (NO) in the brain and are known by its resistance in pathological conditions. Two hundred and forty NADPH-d neurons from NMDA-lesioned striatum and contralateral counterpart were tridimensionally reconstructed at 1, 3 and 7 post-lesion days (PLDs). Cell body and dendritic field areas, length of dendrites by order and fractal dimension were analyzed. There were no significant morphometric differences when NADPH-d+ neurons from lesioned and control striatal regions were compared among PLDs evaluated. Conversely, a conspicuous pallor in striatal neuropil reactivity was evidenced, especially in latter survival time. In addition, we observed a noticeable inflammatory response induced by NMDA. Our results suggest that NADPH-d+ neurons were spared from deleterious effects of acute NMDA excitotoxic damage in the striatum, reinforcing the notion that this cell group is selectively resistant to injury in the nervous system.

Asunto(s)

Cuerpo Estriado/patología , Agonistas de Aminoácidos Excitadores/toxicidad , N-Metilaspartato/toxicidad , NADPH Deshidrogenasa/metabolismo , Neuronas/enzimología , Neuronas/patología , Animales , Cuerpo Estriado/efectos de los fármacos , Encefalitis/inducido químicamente , Masculino , Neuronas/efectos de los fármacos , Ratas , Ratas Wistar

RESUMEN

BACKGROUND: Wnt-5a is a member of the WNT family of secreted lipoglycoproteins, whose expression increases during development; moreover, Wnt-5a plays a key role in synaptic structure and function in the adult nervous system. However, the mechanism underlying these effects is still elusive. MicroRNAs (miRNAs) are a family of small non-coding RNAs that control the gene expression of their targets through hybridization with complementary sequences in the 3' UTR, thereby inhibiting the translation of the target proteins. Several evidences indicate that the miRNAs are actively involved in the regulation of neuronal function. RESULTS: In the present study, we examined whether Wnt-5a modulates the levels of miRNAs in hippocampal neurons. Using PCR arrays, we identified a set of miRNAs that respond to Wnt-5a treatment. One of the most affected miRNAs was miR-101b, which targets cyclooxygenase-2 (COX2), an inducible enzyme that converts arachidonic acid to prostanoids, and has been involved in the injury/inflammatory response, and more recently in neuronal plasticity. Consistent with the Wnt-5a regulation of miR-101b, this Wnt ligand regulates COX2 expression in a time-dependent manner in cultured hippocampal neurons. CONCLUSION: The biological processes induced by Wnt-5a in hippocampal neurons, involve the regulation of several miRNAs including miR-101b, which has the capacity to regulate several targets, including COX-2 in the central nervous system.

Asunto(s)

Ciclooxigenasa 2/análisis , Hipocampo/enzimología , MicroARNs/fisiología , Neuronas/enzimología , Proteínas Wnt/fisiología , Animales , Western Blotting , Células Cultivadas , Regulación hacia Abajo , Expresión Génica , Perfilación de la Expresión Génica , Marcación de Gen , Hipocampo/química , Plasticidad Neuronal , Neuronas/química , Ratas Sprague-Dawley , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteína Wnt-5a

RESUMEN

Neuronal differentiation plays a key role during embryogenesis. However, based on the capacity of neuronal stem cells to either generate or regenerate neurons and because differentiation stops aberrant neuroblasts proliferation, neuronal differentiation is crucial during neuropathological conditions. Although phosphatidylcholine (PtdCho) has been proposed as an important molecule for neurite growth and neuronal regeneration, the identity of the molecular target has remained elusive. This study originally describes that lysophosphatidylcholine (LPtdCho), either exogenously supplied or generated by the imbalance of PtdCho metabolism through the enzymatic action of cytosolic phospholipase A2, acts as a neurotrophic-like factor. We demonstrated that LPtdCho induces neuronal differentiation by activation of the small G protein Ras followed by the Raf/MEK/ERK signaling pathway. Accordingly, LPtdCho redirects neuroblasts gene expression leading to the generation of functional mature neurons expressing ßIII-tubulin and having increased acetylcholinesterase activity and membrane biosynthesis required for neuritogenesis. These findings provide mechanistic details of the role of cytidine-5-diphosphocholine (CDP-choline) and PtdCho as neuroprotectors. Furthermore, as LPtdCho recapitulates the effect of the therapeutic agent retinoic acid, these results open new avenues for drug discovery for the treatment of neuropathological conditions.

Asunto(s)

Linaje de la Célula , Lisofosfatidilcolinas/farmacología , Neuronas/citología , Neuronas/metabolismo , Animales , Biomarcadores/metabolismo , Calcio/metabolismo , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Linaje de la Célula/efectos de los fármacos , Humanos , Lisofosfatidilcolinas/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Modelos Biológicos , Neuronas/efectos de los fármacos , Neuronas/enzimología , Fosfatidilcolinas/metabolismo , Fosfolipasas A2 Citosólicas/metabolismo , Sistemas de Mensajero Secundario , Tretinoina/farmacología , Proteínas ras/metabolismo

RESUMEN

Hydroelectrolytic imbalances, such as saline load (SL), trigger behavioral and neuroendocrine responses, such as thirst, hypophagia, vasopressin (AVP) and oxytocin (OT) release and hypothalamus­pituitary­adrenal (HPA) axis activation. To investigate the participation of the type-1 cannabinoid receptor (CB1R) in these homeostatic mechanisms,male adult Wistar rats were subjected to SL (0.3MNaCl) for four days. SL induced not only increases in the water intake and plasma levels of AVP, OT and corticosterone, as previously described, but also increases in CB1R expression in the lamina terminalis, which integrates sensory afferents, aswell as in the hypothalamus, the main integrative and effector area controlling hydroelectrolytic homeostasis. A more detailed analysis revealed that CB1R-positive terminals are in close apposition with not only axons but also dendrites and secretory granules of magnocellular neurons, particularly vasopressinergic cells. In satiated and euhydrated animals, the intracerebroventricular administration of the CB1R selective agonist ACEA (0.1 µg/5 µL) promoted hyperphagia, but this treatment did not reverse the hyperosmolality-induced hypophagia in the SL group. Furthermore, ACEA pretreatment potentiated water intake in the SL animals during rehydration as well as enhanced the corticosterone release and prevented the increase in AVP and OT secretion induced by SL. The same parameters were not changed by ACEA in the animals whose daily food intake was matched to that of the SL group (Pair-Fed). These data indicate that CB1Rs modulate the hydroelectrolytic balance independently of the food intake during sustained hyperosmolality and hypovolemia.

Asunto(s)

Metabolismo Energético/fisiología , Receptor Cannabinoide CB1/fisiología , Cloruro de Sodio Dietético/farmacología , Equilibrio Hidroelectrolítico , Animales , Ingestión de Alimentos/efectos de los fármacos , Endocannabinoides/farmacología , Metabolismo Energético/efectos de los fármacos , Homeostasis/efectos de los fármacos , Homeostasis/fisiología , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Sistema Hipotálamo-Hipofisario/metabolismo , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Hipovolemia/metabolismo , Masculino , Neuronas/efectos de los fármacos , Neuronas/enzimología , Neuronas/metabolismo , Sistema Hipófiso-Suprarrenal/efectos de los fármacos , Sistema Hipófiso-Suprarrenal/metabolismo , Ratas , Ratas Wistar , Receptor Cannabinoide CB1/agonistas , Equilibrio Hidroelectrolítico/efectos de los fármacos

RESUMEN

BACKGROUND AND OBJECTIVES: Studies in humans and animal models have established a close relationship between early environment insult and subsequent risk of development of non-communicable diseases, including the cardiovascular. Whereas experimental evidences highlight the early undernutrition and the late cardiovascular disease relation, the central mechanisms linking the two remain unknown. Owing to the oxidative balance influence in several pathologies, the aim of the present study was to evaluate the effects of maternal undernutrition (i.e. a low-protein (LP) diet) on oxidative balance in the brainstem. METHODS AND RESULTS: Male rats from mothers fed with an LP diet (8% casein) throughout the perinatal period (i.e. gestation and lactation) showed 10× higher lipid peroxidation levels than animals treated with normoprotein (17% casein) at 100 days of age. In addition, we observed the following reductions in enzymatic activities: superoxide dismutase, 16%; catalase, 30%; glutathione peroxidase, 34%; glutathione-S-transferase, 51%; glutathione reductase, 23%; glucose-6-phosphate dehydrogenase, 31%; and in non-enzymatic glutathione system, 46%. DISCUSSION: This study is the first to focus on the role of maternal LP nutrition in oxidative balance in a central nervous system structure responsible for cardiovascular control in adult rats. Our data observed changes in oxidative balance in the offspring, therefore, bring a new concept related to early undernutrition and can help in the development of a new clinical strategy to combat the effects of nutritional insult. Wherein the central oxidative imbalance is a feasible mechanism underlying the hypertension risk in adulthood triggered by maternal LP diet.

Asunto(s)

Antioxidantes/metabolismo , Tronco Encefálico/metabolismo , Dieta con Restricción de Proteínas/efectos adversos , Lactancia , Fenómenos Fisiologicos Nutricionales Maternos , Neuronas/metabolismo , Estrés Oxidativo , Animales , Tronco Encefálico/enzimología , Femenino , Glutatión/metabolismo , Glutatión Transferasa/metabolismo , Peroxidación de Lípido , Masculino , Proteínas del Tejido Nervioso/metabolismo , Neuronas/enzimología , Oxidación-Reducción , Oxidorreductasas/metabolismo , Embarazo , Complicaciones del Embarazo/etiología , Complicaciones del Embarazo/metabolismo , Complicaciones del Embarazo/fisiopatología , Deficiencia de Proteína/etiología , Deficiencia de Proteína/metabolismo , Deficiencia de Proteína/fisiopatología , Ratas Wistar

RESUMEN

BACKGROUND: Wnt-5a is a member of the WNT family of secreted lipoglycoproteins, whose expression increases during development; moreover, Wnt-5a plays a key role in synaptic structure and function in the adult nervous system. However, the mechanism underlying these effects is still elusive. MicroRNAs (miRNAs) are a family of small non-coding RNAs that control the gene expression of their targets through hybridization with complementary sequences in the 3' UTR, thereby inhibiting the translation of the target proteins. Several evidences indicate that the miRNAs are actively involved in the regulation of neuronal function. RESULTS: In the present study, we examined whether Wnt-5a modulates the levels of miRNAs in hippocampal neurons. Using PCR arrays, we identified a set of miRNAs that respond to Wnt-5a treatment. One of the most affected miRNAs was miR-101b, which targets cyclooxygenase-2 (COX2), an inducible enzyme that converts arachidonic acid to prostanoids, and has been involved in the injury/inflammatory response, and more recently in neuronal plasticity. Consistent with the Wnt-5a regulation of miR-101b, this Wnt ligand regulates COX2 expression in a time-dependent manner in cultured hippocampal neurons. CONCLUSION: The biological processes induced by Wnt-5a in hippocampal neurons, involve the regulation of several miRNAs including miR-101b, which has the capacity to regulate several targets, including COX-2 in the central nervous system

Asunto(s)

Animales , Ratas , MicroARNs/fisiología , Ciclooxigenasa 2/análisis , Proteínas Wnt/fisiología , Hipocampo/enzimología , Neuronas/enzimología , Regulación hacia Abajo , Expresión Génica , Células Cultivadas , Western Blotting , Ratas Sprague-Dawley , Marcación de Gen , Perfilación de la Expresión Génica , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteína Wnt-5a , Hipocampo/química , Plasticidad Neuronal , Neuronas/química