RESUMEN
BACKGROUND: The enhanced view totally extraperitoneal (eTEP) approach is becoming increasingly more widely accepted as a promising technique in the treatment of ventral hernia. However, evidence is still lacking regarding the perioperative, postoperative and long-term outcomes of this technique. The aim of this meta-analysis is to summarize the current available evidence regarding the perioperative and short-term outcomes of ventral hernia repair using eTEP. STUDY DESIGN: A systematic search was performed of PubMed, EMBASE, Cochrane Library and Web of Science electronic databases to identify studies on the laparoscopic or robotic-enhanced view totally extraperitoneal (eTEP) approach for the treatment of ventral hernia. A pooled meta-analysis was performed. The primary end point was focused on short-term outcomes regarding perioperative characteristics and postoperative parameters. RESULTS: A total of 13 studies were identified involving 918 patients. Minimally invasive eTEP resulted in a rate of surgical site infection of 0% [95% CI 0.0-1.0%], a rate of seroma of 5% [95% CI 2.0-8.0%] and a rate of major complications (Clavien-Dindo III-IV) of 1% [95% CI 0.0-3.0%]. The rate of intraoperative complications was 2% [95% CI 0.0-4.0%] with a conversion rate of 1.0% [95% CI 0.0-3.0%]. Mean hospital length of stay was 1.77 days [95% CI 1.21-2.24]. After a median follow-up of 6.6 months (1-24), the rate of recurrence was 1% [95% CI 0.0-1.0%]. CONCLUSION: Minimally invasive eTEP is a safe and effective approach for ventral hernia repair, with low reported intraoperative complications and good outcomes.
Asunto(s)
Hernia Ventral , Hernia Incisional , Laparoscopía , Humanos , Herniorrafia/efectos adversos , Herniorrafia/métodos , Mallas Quirúrgicas , Hernia Ventral/cirugía , Laparoscopía/efectos adversos , Laparoscopía/métodos , Complicaciones Intraoperatorias , Hernia Incisional/cirugíaRESUMEN
Induction of neuroprotective heat-shock proteins via pharmacological Hsp90 inhibitors is currently being investigated as a potential treatment for neurodegenerative diseases. Two major hurdles for therapeutic use of Hsp90 inhibitors are systemic toxicity and limited central nervous system permeability. We demonstrate here that chronic treatment with a proprietary Hsp90 inhibitor compound (OS47720) not only elicits a heat-shock-like response but also offers synaptic protection in symptomatic Tg2576 mice, a model of Alzheimer's disease, without noticeable systemic toxicity. Despite a short half-life of OS47720 in mouse brain, a single intraperitoneal injection induces rapid and long-lasting (>3 days) nuclear activation of the heat-shock factor, HSF1. Mechanistic study indicates that the remedial effects of OS47720 depend upon HSF1 activation and the subsequent HSF1-mediated transcriptional events on synaptic genes. Taken together, this work reveals a novel role of HSF1 in synaptic function and memory, which likely occurs through modulation of the synaptic transcriptome.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Factores de Transcripción/metabolismo , Enfermedad de Alzheimer/metabolismo , Animales , Proteínas de Unión al ADN/genética , Modelos Animales de Enfermedad , Proteínas HSP90 de Choque Térmico/metabolismo , Factores de Transcripción del Choque Térmico , Humanos , Memoria/fisiología , Trastornos de la Memoria/metabolismo , Trastornos de la Memoria/terapia , Ratones , Ratones Transgénicos , Factores de Transcripción/genéticaRESUMEN
PURPOSE: No definitive surgical treatment for non-acute pilonidal disease has been established thus far. We herein report the short-term and long-term outcomes of 74 consecutive patients who underwent the cleft lift procedure for non-acute pilonidal disease. METHODS: A total of 74 consecutive patients who underwent the cleft lift procedure for the treatment of non-acute pilonidal disease were evaluated. RESULTS: Complete healing was achieved in 54 patients (73%). Wound seroma was observed in 12 patients (15%) in the first week, and this persisted until the second week in 10 patients (13%). Partial dehiscence was found in eight patients (11%). One patient presented with complete wound dehiscence (1%), and another experienced early postoperative bleeding (1%). Wound infection was observed in one patient (1%). The median follow-up period was 51.5 months (range 15-88 months). Three cases of recurrences were observed, which occurred after 51, 42 and 12 months of follow-up. CONCLUSIONS: If longer-term follow-up is achieved, definitive conclusions may be obtained. However, the present results suggest that the cleft lift procedure may become the gold standard technique for the surgical management of non-acute pilonidal disease.
Asunto(s)
Seno Pilonidal/cirugía , Procedimientos Quirúrgicos Operativos/métodos , Adolescente , Adulto , Anciano , Nalgas , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Región Sacrococcígea , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
It has been shown that insoluble Gd chelates are suitable MRI contrast agents for conditional activation by intracellular lipases. The DTPA-based, insoluble, inactive contrast agent was internalized into dendritic cells by phagocytosis. Cleavage of long aliphatic side chains by intracellular lipase activity leads to the contrast agents solubility and hereby its activation depending on the enzyme expression. Uptake and activation of the contrast agent was much reduced in Flt3+ CD11b+ progenitor cells. Detectability limits in the T(1)-weighted MR images were estimated in phantoms and in vivo in the rat brain. Marginal toxic effects were only observed at very high concentrations of the contrast agent. The chelate can easily be modified to be targeted by enzymes expressed during specific change of cell status like activation or differentiation. Such a system is suitable for functional cellular in vivo MR imaging.
Asunto(s)
Encéfalo/citología , Trasplante de Células/fisiología , Medios de Contraste , Gadolinio DTPA , Imagen por Resonancia Magnética/métodos , Animales , Células de la Médula Ósea/fisiología , Fenómenos Fisiológicos Celulares , Medios de Contraste/toxicidad , ADN Complementario/biosíntesis , ADN Complementario/genética , Células Dendríticas/fisiología , Gadolinio DTPA/toxicidad , Perfilación de la Expresión Génica , Lipasa/biosíntesis , Ratones , Ratones Endogámicos C57BL , Modelos Anatómicos , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Complementario/biosíntesis , ARN Complementario/genética , Ratas , Ratas Wistar , Células Madre/fisiologíaRESUMEN
Transient focal ischaemia by middle cerebral artery occlusion (MCAO) may produce cell death, but the mechanisms leading to cell death differ in the infarct core and in the penumbra, the immediate zone surrounding the infarct core. In the present study, transient focal ischaemia to adult rats was produced by intraluminal occlusion of the middle cerebral artery for 1 h followed by 0 h (n=6), 1 h (n=10), 4 h (n=8), 6 h (n=2) and 12 h (n=3) of reperfusion. The present model of ischaemia causes a large cortico-striatal infarct extending through the mediolateral cortex and dorsolateral striatum at 12 h. The expression and subcellular distribution of several proteins involved in apoptosis have been examined in the penumbra and in the infarct core by using combined methods of immunohistochemistry, cell subfractionation and Western blotting. Transient focal ischaemia by MCAO results in activation of complex signal pathways for cell death in the penumbra. Increased expression of Bcl-2 and Bax, but not of Bcl-x, occurs in the penumbra at the time when Bax translocates from the cytosol to the mitochondria, cytochrome c is released to the cytoplasm and active caspase-3 is expressed. Bax translocation, cytochrome c release and active caspase-3 are observed at 4 h, but not at 1 h, following reperfusion, and together indicate activation of the caspase-dependent pathway of apoptosis in the penumbra. In contrast, reduced Bax expression but not Bax translocation and cytochrome c release occurs in the infarct core, thus suggesting apoptosis signals restricted to the penumbra. In addition, increased expression of an apoptosis-inducing factor in the cytoplasm and nuclei of selected cells shows, for the first time, activation of the caspase-independent mitochondrial pathway in the penumbra following transient focal ischaemia and reperfusion.
Asunto(s)
Isquemia Encefálica/metabolismo , Isquemia Encefálica/patología , Caspasas/metabolismo , Neuronas/patología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Animales , Apoptosis , Factor Inductor de la Apoptosis , Western Blotting , Isquemia Encefálica/etiología , Citocromos c/metabolismo , Citosol/metabolismo , Activación Enzimática/fisiología , Flavoproteínas/biosíntesis , Inmunohistoquímica , Infarto de la Arteria Cerebral Media/complicaciones , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patología , Masculino , Proteínas de la Membrana/biosíntesis , Mitocondrias/metabolismo , Neuroglía/metabolismo , Neuroglía/patología , Neuronas/metabolismo , Transporte de Proteínas , Proteínas Proto-Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Ratas , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Factores de Tiempo , Proteína X Asociada a bcl-2 , Proteína bcl-XRESUMEN
We studied whether pro-survival Akt was activated after transient focal cerebral ischemia and whether it inhibited pro-apoptotic Bad. Phosphorylation of Akt (serine-473) was enhanced in cortex after 1-hour ischemia, and also after 1h and 6 h of reperfusion, but it returned back to that in controls by 24 h. After this first wave of Akt activation, a second increase was observed between 4 and 7 days. In striatum, only the late Akt activation was seen. In contrast to Akt, no Bad phosphorylation (serine-136) was detected after ischemia. Therefore, injury spontaneously activated Akt, but this did not suppress Bad signalling. It is proposed that further pharmacological activation of Akt shortly after ischemia might promote cell survival, whereas Akt activation at longer time points is involved with glial reactivity.
Asunto(s)
Apoptosis/fisiología , Isquemia Encefálica/enzimología , Proteínas Portadoras/metabolismo , Supervivencia Celular/fisiología , Corteza Cerebral/enzimología , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas/metabolismo , Daño por Reperfusión/enzimología , Secuencia de Aminoácidos/fisiología , Animales , Isquemia Encefálica/fisiopatología , Corteza Cerebral/fisiopatología , Proteínas del Choque Térmico HSP72 , Proteínas de Choque Térmico/metabolismo , Masculino , Neostriado/enzimología , Neostriado/fisiopatología , Fosforilación , Proteínas Proto-Oncogénicas c-akt , Ratas , Ratas Sprague-Dawley , Daño por Reperfusión/fisiopatología , Serina/metabolismo , Transducción de Señal/fisiología , Factores de Tiempo , Proteína Letal Asociada a bclRESUMEN
Matrix metalloproteinases (MMPs) degrade the extracellular matrix and carry out key functions during development and after injury. By means of zymography, Western blot and immunohistochemistry, we studied MMP-2 (gelatinase A) and MMP-9 (gelatinase B) in rat brain after focal cerebral ischemia. The control rat brain showed constitutive MMP-2 and, to a lesser extent, MMP-9, which were mainly present as prozymogens. MMP-2 protein was located in the cell body of neurons, glia, and endothelium, whereas MMP-9 was associated to neurons and myelinated fibre tracts. Ischemia greatly increased MMP activation in two temporal waves, in the first one, MMP-9 protein was induced from 4 h to 4 days, and also a small and short-lasting increase in MMP-2 was detected at 4 h. The second wave showed a massive increase in MMP-2 protein expression and activation by day 4, which was compatible with abundant MMP-2 in reactive microglia/macrophages. Our results are compatible with progressive induction of MMP-9 proform, likely in neurons, shortly after ischemia. For MMP-2, the results suggest a discrete production immediately after reperfusion, while a very enhanced expression and activation of MMP-2 attributable to microglia/macrophages occurs on day 4, and it might contribute to the phagocytic action of these reactive cells.
Asunto(s)
Encéfalo/enzimología , Ataque Isquémico Transitorio/enzimología , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Animales , Barrera Hematoencefálica , Western Blotting , Endotelio Vascular/enzimología , Activación Enzimática , Inducción Enzimática , Precursores Enzimáticos/metabolismo , Técnicas para Inmunoenzimas , Macrófagos/enzimología , Masculino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Fibras Nerviosas Mielínicas/enzimología , Proteínas del Tejido Nervioso/genética , Neuroglía/enzimología , Neuronas/enzimología , Ratas , Ratas Sprague-Dawley , Daño por Reperfusión/enzimología , Factores de TiempoRESUMEN
Growth factors promote cell growth and survival and protect the brain from developing injury after ischemia. In this article, the authors examined whether transforming growth factor-alpha (TGF-alpha) was protective in transient focal ischemia and whether alteration of cerebral circulation was involved. Rats received intraventricular TGF-alpha (50 ng, either split into 2 doses given 30 minutes before and 30 minutes after middle cerebral artery occlusion (MCAO), or 1 dose given 30 minutes after MCAO) or vehicle. Rats were subjected to 1-hour intraluminal MCAO and cerebral blood flow was recorded continuously by laser-Doppler flowmetry. Infarct volume was measured 1 and 4 days later. The effects of TGF-alpha on arterial tone were assessed in isolated rabbit basilar and common carotid arteries. Transforming growth factor-alpha before and after ischemia reduced infarct volume by 70% at 1 day and 50% at 4 days. Transforming growth factor-alpha given only after ischemia also did reduce infarct volume by 70% at 1 day and 80% at 4 days. The protective effect was more marked in cortex than in striatum. Transforming growth factor-alpha did not change cortical microvascular perfusion and did not modify arterial passive tone nor agonist-induced active tone. It can be concluded that TGF-alpha reduces infarct volume, even when the factor is exclusively administered at reperfusion, and that this effect is not mediated by changes in microvascular perfusion or cerebral arteries. It is therefore suggested that TGF-alpha has a protective effect against neuronal cell death after transient focal ischemia.
Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Circulación Cerebrovascular/efectos de los fármacos , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Factor de Crecimiento Transformador alfa/farmacología , Animales , Arteria Basilar/efectos de los fármacos , Arterias Carótidas/efectos de los fármacos , Técnicas In Vitro , Masculino , Microcirculación/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Conejos , Ratas , Ratas Sprague-Dawley , Vasoconstricción/efectos de los fármacosRESUMEN
The role of gene induction (expression of HSP72 and c-JUN proteins) and delayed ischemic cell death (in situ labeling of DNA fragmentation) have been investigated in the goat hippocampus after transient global cerebral ischemia. The animals were subjected to 20-min ischemia (bilateral occlusion of the external carotid arteries plus bilateral jugular vein compression) and allowed to reperfuse for 2 h, and then 1, 3, and 7 days. Histological signs of cell loss were not found in the hippocampus at 2 h, 1 day, or 3 days of reperfusion. However, such an ischemic insult produced extensive, selective, and delayed degeneration in the hippocampus, as 68% of the neurons in CA1 had died at 7 days, but cell loss was not detected in CA3 and dentate gyrus fields. Concomitantly, a high percentage of TUNEL-positive CA1 neurons (60+/-9%, mean +/- SEM) was seen at 7 days, but not at the earlier time points. Mild induction of HSP72 was detected in the goat hippocampus after ischemia. The maximum percentage of HSP72-positive neurons (10-15%) was shown at 3 days of reperfusion and was concentrated mainly in the CA3 field, subiculum, and hilus, rather than in the CA1 field, whereas HSP72 expression was hardly detected at 7 days. At this later time point, scattered induction of nuclear c-JUN was found in a few neurons. The results show that: 1) postischemic delayed neuronal death selectively affects the CA1 field in the goat hippocampus, a phenomenon which seems to take longer to develop than in previously reported rodent models; and 2) postischemic expression of c-JUN does not appear to be related to cell death or survival, while the inability of most CA1 neurons to express HSP72 could contribute to neuronal death.
Asunto(s)
Isquemia Encefálica/genética , Isquemia Encefálica/metabolismo , Fragmentación del ADN , Cabras/fisiología , Proteínas de Choque Térmico/metabolismo , Proteínas Proto-Oncogénicas c-jun/metabolismo , Animales , Isquemia Encefálica/patología , Isquemia Encefálica/fisiopatología , Muerte Celular/fisiología , Femenino , Proteínas del Choque Térmico HSP72 , Neuronas/fisiología , Factores de Tiempo , Distribución TisularRESUMEN
Matrix metalloproteinases degrade the extracellular matrix and are involved in a variety of diseases, including inflammatory diseases of the central nervous system. Here we estimated the content of gelatinase in rat brain under control conditions and 4 h after transient focal ischemia using gelatinolytic extraction and zymographic analysis. We also examined the expression of the MMP-9 and MMP-2 proteins by Western blot. Using the zymographic apparent gelatinase activity we estimated that brain gelatinase content was 0.44 ng/mg of protein. Ischemia induced a 1.7-fold increase at 4 h, thus showing an early MMP response to the ischemic injury. The main increase was seen for the MMP-9 proform, which was accompanied by enhanced MMP-9 protein expression. We suggest that basal cerebral MMP-9 and MMP-2 activities are involved in the maintenance of the extracellular matrix and prevent substrate accumulation, while enhanced postischemic MMP activity before cell death may contribute to edema formation and blood-brain barrier breakdown.
Asunto(s)
Encéfalo/enzimología , Gelatinasas/metabolismo , Ataque Isquémico Transitorio/enzimología , Animales , Colagenasas/metabolismo , Activación Enzimática , Precursores Enzimáticos/metabolismo , Gelatinasas/análisis , Cinética , Masculino , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
JAK/STAT is one of the pathways bearing signals from the cell membrane to the nucleus in response to extracellular growth factors and cytokines. In the present study, we examined the cellular distribution of Jak1 and Stat3, and activation of the JAK/STAT pathway following transient focal cerebral ischemia in the rat. Jak1 was mainly seen in white matter astrocytes and in certain neurons. Notably, large pyramidal neurons of cortical layer V showed the highest neuronal Jak1 expression within cerebral cortex and, in addition, expressed Stat3 indicating that the JAK/STAT pathway is involved in signaling in the corticofugal projection system. Shortly following ischemia, Jak1 immunoreactive astrocytes located in the ipsilateral neighbouring white matter and ischemic cortex and striatum showed nuclear translocation of Stat3. These features were maintained in large reactive astrocytes that surrounded the infarct from 3 to 7 days. At these later times, the abundant reactive microglia/macrophages were strongly immunoreactive to Stat3 and, to a lesser extent, Jak1. Two main protein complexes showing DNA binding activity at the sis-inducible element site were found under basal conditions, followed by changes in this pattern following ischemia concomitant with neuronal cell loss and activation of glia. This study showed basal cerebral activity of JAK/STAT signaling pathway, involving Jak1 and Stat3 proteins, and selective activation following ischemia. It is suggested that the kinase activity of Jak1 mediates nuclear translocation of Stat3 in astrocytes, and that this signaling pathway is involved in the astroglial response to focal cerebral ischemia.
Asunto(s)
Astrocitos/metabolismo , Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Transactivadores/metabolismo , Animales , Astrocitos/patología , Encéfalo/patología , Isquemia Encefálica/patología , Inmunohistoquímica , Janus Quinasa 1 , Masculino , Ratas , Ratas Sprague-Dawley , Factor de Transcripción STAT3RESUMEN
Cyclooxygenase-2, a key enzyme in prostanoid synthesis, is induced by inflammatory stimuli and it is associated with cell death after cerebral ischemia. Here we evaluated whether cyclooxygenase-2 was induced after a short (10-min) episode of focal ischemia, mild enough not to cause inflammation or cell death. One-hour ischemia leading to brain infarct was studied for comparative purposes. Induction of cyclooxygenase-2 mRNA and protein was detected after both 10-min and 1-h ischemia. However, signs of edema were only apparent after 1-h, but not 10-min ischemia, and only rats subjected to 1-h ischemia had developed brain infarct at 4 days. Therefore, cyclooxygenase-2, not linked with neural cell death or inflammation, is induced after focal ischemia.
Asunto(s)
Isquemia Encefálica/enzimología , Encéfalo/enzimología , Isoenzimas/biosíntesis , Prostaglandina-Endoperóxido Sintasas/biosíntesis , Animales , Arteriopatías Oclusivas , Encéfalo/patología , Isquemia Encefálica/complicaciones , Isquemia Encefálica/patología , Infarto Cerebral/enzimología , Infarto Cerebral/etiología , Infarto Cerebral/patología , Ciclooxigenasa 2 , Inducción Enzimática , Inflamación/patología , Isoenzimas/genética , Neuronas/patología , Prostaglandina-Endoperóxido Sintasas/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
Transforming growth factor-alpha (TGF-alpha) is a ligand for the epidermal growth factor (EGF) receptor (EGFR), and is more abundant than EGF in the brain. The authors studied whether administration of exogenous TGF-alpha into the brain can protect neurons against ischemia in a model of permanent middle cerebral artery (MCA) occlusion in the rat, and whether any effect of TGF-alpha was mediated by EGFR by administering 4,5-dianilinophthalimide (DAPH), a protein-tyrosine kinase inhibitor with high selectivity for EGFR. Rats received either TGF-alpha (10 or 25 ng), DAPH (100 ng), DAPH plus TGF-alpha (25 ng), or vehicle in the ipsilateral first ventricle. Drugs were administered twice: 30 minutes before and 30 minutes after MCA occlusion, and infarct volume was evaluated 24 hours later. Transforming growth factor-alpha at the dose of 25 ng caused a statistically significant reduction of infarct volume (60%) in relation to ischemic rats administered vehicle. This reduction was no longer seen when TGF-alpha was administered in combination with DAPH. The present results show that TGF-alpha can protect neurons from ischemic damage, and that this effect is mediated by EGFR. It is suggested that activation of EGFR-mediated intracellular signalling pathways contributes to the survival of neural cells susceptible to ischemic injury.
Asunto(s)
Arteriopatías Oclusivas/complicaciones , Arterias Cerebrales , Infarto Cerebral/etiología , Infarto Cerebral/patología , Receptores ErbB/fisiología , Fármacos Neuroprotectores/farmacología , Factor de Crecimiento Transformador alfa/farmacología , Animales , Edema Encefálico/patología , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Inhibidores Enzimáticos/farmacología , Receptores ErbB/efectos de los fármacos , Procesamiento de Imagen Asistido por Computador , Masculino , Ftalimidas/farmacología , Ratas , Ratas Sprague-DawleyRESUMEN
Nuclear factor-kappaB (NF-kappaB) becomes activated under inflammatory conditions and triggers induction of gene expression. Here, activation of NF-kappaB was studied after transient middle cerebral artery occlusion in the rat. Expression of p65 and p50, protein subunits of NF-kappaB, was examined by Western blotting, and immunohistochemistry for p65 was carried out. Double-labelling with specific markers for astroglia and microglia was used for cell type identification. Neurons located within and surrounding the ischemic core were identified during the first 24 h post-ischemia by using an antibody against 72-kDa heat shock protein. NF-kappaB binding activity was evaluated at different times post-ischemia with electrophoretic mobility gel shift assays. The results showed constitutive expression of p65 and p50, and NF-kappaB binding activity. Basal p65 was seen in certain neurons and resting astrocytes. Constitutive NF-kappaB binding activity was attributable to one main protein complex possibly formed in neurons and astrocytes, although two minor complexes were also detected. At 1 day post-ischemia selective induction of p65 was seen in neurons located in a penumbra-like area. At this time, however, no disturbances of basal NF-kappaB binding activity were found. Western blotting showed delayed induction of p65 several days after ischemia, whereas no changes were detected for p50. From 4 days post-ischemia, a substantial increase in the amount of p65 was detected due to induction in reactive astrocytes and microglia/macrophages. This was correlated with a robust enhancement of NF-kappaB binding activity with formation of three major specific complexes binding DNA. It is proposed that the highly inducible NF-kappaB complexes resulted from induction of p65 and activation of NF-kappaB in post-ischemic reactive glia.
Asunto(s)
Química Encefálica/fisiología , Isquemia Encefálica/fisiopatología , FN-kappa B/metabolismo , Animales , Arteriopatías Oclusivas/fisiopatología , Western Blotting , Trastornos Cerebrovasculares/fisiopatología , Cartilla de ADN , Regulación de la Expresión Génica/fisiología , Inmunohistoquímica , Masculino , FN-kappa B/análisis , FN-kappa B/genética , Neuroglía/fisiología , Ratas , Ratas Sprague-DawleyRESUMEN
Severe transient focal cerebral ischemia causes brain infarction with a strong glial reaction. We have studied whether postischemic reactive glial cells express epidermal growth factor receptor (EGFR) following middle cerebral artery occlusion in the rat. We have also looked for signs of proliferating activity, as EGFR is known to be involved in cell growth and proliferation in certain non-neural cells. EGFR was studied using three different antibodies which were found to stain for a tyrosine-phosphorylated protein (p170) corresponding to the membrane-anchored EGFR. Neurons of the control brain were strongly immunoreactive to EGFR, but a decrease of EGFR-immunoreactivity was seen in the ipsilateral brain side from 24 h postischemia due to neuronal loss. However, the presence of abundant glial cells strongly immunoreactive to EGFR became apparent in this area from 4 days postischemia onward. The use of microglial (lectin or OX-42) and astroglial (GFAP) markers showed that these postischemic EGFR-stained cells were reactive microglia/macrophages and astroglia. The subcellular localization of EGFR in reactive microglia/macrophages was compatible with the network of the Golgi apparatus, as revealed with an antibody against a peripheral membrane-bound protein of the Golgi. The presence of abundant proliferating cells in the ischemic brain was detected from 4 days postischemia with an antibody against proliferating cell nuclear antigen. Proliferating reactive microglia/macrophages were abundant within the infarcted brain side, whereas proliferating astrocytes were found mainly in the immediate periphery of the infarct limiting the necrotic area from the undamaged tissue. These proliferating cells were immunoreactive to EGFR. The results show the presence of EGFR in postischemic reactive glial cells and suggest that EGFR-dependent pathways mediate signal transduction in reactive glia following transient focal cerebral ischemia.
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Receptores ErbB/metabolismo , Ataque Isquémico Transitorio/metabolismo , Neuroglía/metabolismo , Neuroglía/patología , Animales , Arteriopatías Oclusivas/metabolismo , Arteriopatías Oclusivas/patología , División Celular , Enfermedades Arteriales Cerebrales/metabolismo , Enfermedades Arteriales Cerebrales/patología , Ataque Isquémico Transitorio/patología , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
Stat1 has a dual function as signal transducer and activator of transcription, and is activated in response to growth factors and cytokines. We examined Stat1 in the rat brain during development and following transient focal ischemia, using Western immunoblotting. Two bands of 91 and 84 kDa, corresponding to Stat1 alpha and Stat1 beta forms, were found with an intensity that increased from postnatal day 0 to adulthood in cerebellum and cerebral cortex. Ischemia caused a strong induction of Stat1 in the ipsilateral cortex after 4, 7 and 15 days, but not at 6 or 24 h. These results show that Stat1 is normally expressed in the postnatal and adult rat brain and is induced under brain infarction.
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Encéfalo/metabolismo , Proteínas de Unión al ADN/biosíntesis , Ataque Isquémico Transitorio/metabolismo , Proteínas del Tejido Nervioso/biosíntesis , Transducción de Señal/fisiología , Transactivadores/biosíntesis , Animales , Western Blotting , Encéfalo/crecimiento & desarrollo , Cerebelo/irrigación sanguínea , Cerebelo/crecimiento & desarrollo , Cerebelo/metabolismo , Masculino , Peso Molecular , Ratas , Ratas Sprague-Dawley , Factor de Transcripción STAT1RESUMEN
Stat3 is a member of a recently identified family of proteins named STATs for their ability to act as signal transducers and activators of transcription. Stimulation of epidermal growth factor or cytokine receptors can cause activation of Stat3 and transduction of specific responses to the nucleus. Here the presence of Stat3 has been examined in the rat cerebellum at different times during postnatal development and adulthood by means of immunohistochemistry and western blotting. In addition, DNA binding activity at the sis-inducible element that is present in the promoter of the c-fos gene has been studied by electrophoretic mobility shift assay. The results have shown that Stat3 p92 is abundant in the rat cerebellum. Stat3 was found in the external granule cell layer and also within the molecular layer from postnatal day (P) 0 to P7. From P15 to the adult, the internal granule cell layer and Purkinje cells were also stained for Stat3. Nuclear extracts were found to contain DNA binding activity to the sis-inducible element during development and adulthood. Supershift assays demonstrated that Stat3 mediates the formation of one protein-DNA complex. The present results suggest that Stat3 participates in intracellular signaling and is involved in maintaining basal c-fos expression in the cerebellum of the developing and adult rat under physiological conditions.
Asunto(s)
Cerebelo/crecimiento & desarrollo , Proteínas de Unión al ADN/genética , Oncogenes/fisiología , Transactivadores/genética , Transcripción Genética/fisiología , Proteínas de Fase Aguda/análisis , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/inmunología , Animales , Especificidad de Anticuerpos , Western Blotting , Cerebelo/química , ADN/análisis , ADN/metabolismo , Proteínas de Unión al ADN/análisis , Proteínas de Unión al ADN/inmunología , Electroforesis , Regulación del Desarrollo de la Expresión Génica/fisiología , Inmunohistoquímica , Masculino , Neuroglía/química , Neuroglía/citología , Neuroglía/fisiología , Células de Purkinje/química , Células de Purkinje/citología , Células de Purkinje/fisiología , Ratas , Ratas Sprague-Dawley , Factor de Transcripción STAT3 , Transducción de Señal/genética , Transactivadores/análisis , Transactivadores/inmunologíaRESUMEN
Dopaminergic neurons of the substantia nigra pars compacta were examined in the rat brain following striatal infarction subsequent to transient focal cerebral ischemia. Rats had the middle cerebral artery occluded for 2 h or were sham-operated, and tyrosine hydroxylase immunoreactivity was evaluated by Western blot and immunohistochemistry at different times ranging from 1 to 60 days after ischemia. The number of tyrosine hydroxylase-immunoreactive cells in the substantia nigra pars compacta was counted under the light microscope and compared to that in the contralateral side and controls. No changes of tyrosine hydroxylase immunoreactivity were detected in the ipsilateral versus the contralateral substantia nigra of sham-operated rats or 1 day after ischemia. However, a statistically significant reduction of tyrosine hydroxylase-immunoreactive cells became apparent in the ipsilateral compared with the contralateral substantia nigra at 7 and 14 days after ischemia. This reduction showed a clear recovery at 30 days after ischemia, and no signs of difference between the ipsilateral and the contralateral side were apparent by 60 days. Therefore, the reduction of tyrosine hydroxylase immunoreactivity in the ipsilateral substantia nigra was only transiently seen from 1 to 2 weeks following ischemia. The observed loss of tyrosine hydroxylase was not accompanied by signs of cell death or gliosis in the ipsilateral pars compacta. The present results show a transitory reduction of tyrosine hydroxylase immunoreactivity in the ipsilateral substantia nigra pars compacta after focal ischemia and suggest that striatal infarction causes a transient deficit of dopaminergic function.
Asunto(s)
Infarto Cerebral/metabolismo , Cuerpo Estriado/irrigación sanguínea , Ataque Isquémico Transitorio/metabolismo , Sustancia Negra/enzimología , Tirosina 3-Monooxigenasa/inmunología , Animales , Anticuerpos Monoclonales , Arteriopatías Oclusivas/metabolismo , Recuento de Células , Infarto Cerebral/etiología , Cuerpo Estriado/patología , Lateralidad Funcional/fisiología , Proteína Ácida Fibrilar de la Glía/análisis , Proteína Ácida Fibrilar de la Glía/inmunología , Ataque Isquémico Transitorio/complicaciones , Masculino , Neuronas/química , Neuronas/citología , Neuronas/enzimología , Ratas , Ratas Sprague-Dawley , Sustancia Negra/citología , Tirosina 3-Monooxigenasa/análisisRESUMEN
Stat3, a member of the family of cytoplasmic signal transducers and activators of transcription, was found in the rat brain in vivo under physiological conditions and was stimulated following transient focal cerebral ischaemia. A transient episode of middle cerebral artery occlusion induced a strong microglial response in the areas undergoing neural cell death from 4 days after middle cerebral artery occlusion. This was accompanied by increased expression of Stat3 in the ipsilateral cortex and striatum, as revealed by Western blotting of tissue extracts. Immunohistochemistry showed strong induction of Stat3 in reactive microglial cells 4, 7 and 15 days after cerebral ischaemia. Stat3 was seen in the microglia cytoplasm, but in many microglial cells immunoreactivity was also distributed within the nucleus. These results suggest that Stat3 mediates signal transduction and activates transcription in reactive microglia in vivo following brain ischaemia.