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Chronic migraine is a disabling neurovascular disorder that ranks amongst the top causes of years lived with disability worldwide. The duration and the frequency of migraine affect cognitive and affective domains, inducing worsening of memory, executive functions, orientation and causing anxiety. Population-based studies report a worrying level of resistance to treatments. Therefore, this study aims: 1) to assess efficacy of monoclonal antibodies (mAbs) directed towards the calcitonin gene-related peptide (CGRP) or its receptor (CGRP-R) for chronic migraine resistant to current preventatives; 2) to design a clinical trial protocol to evaluate the efficacy and safety of combination therapy utilizing anti-CGRP/CGRP-R together with onabotulinumtoxin A in patients suffering from resistant chronic migraine; 3) to provide a molecular rationale for combination therapy. A controlled trial is warranted as pooled analysis of real-world data from our group highlighted that combined treatment provides ≥50% reduction vs. baseline (onabotulinumtoxin A) of monthly headache days (MHDs) in up to 58.8% of patients, but there has been only sparse application of this combined therapy to date. The mAbs chosen are: erenumab, because its combination effect with onabotulinumtoxin A improved symptoms in 65% of patients; eptinezumab, due to its faster action. The results highlight that early diagnosis of migraine improves therapeutic outcomes with mAbs alone, confirming their effectiveness and the need for an adequately powered clinical trial evaluating the safety and potential superior effectiveness of eptinezumab/erenumab and onabotulinumtoxin A together.
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Up to 80 % nursing home residents with dementia experiences chronic pain. Contextually, 97 % presents fluctuant neuropsychiatric symptoms (NPS). Among the most challenging is agitation, connected with undertreated pain and managed through neuroleptics doubling death risk. Evidence is accumulating in favor of the involvement of the endocannabinoid system in nociception and NPS. This double-blind, placebo-controlled, randomized trial (NAbiximols Clinical Translation To the treatment of Pain and Agitation In Severe Dementia [NACTOPAISD]) aims at investigating efficacy and safety of oral spray nabiximols, containing Δ9-tetrahydrocannabinol and cannabidiol (Sativex®), for pain and agitation treatment in severe dementia patients (Mini-Mental State Examination ≤ 12) over 65. The coprimary endpoints are efficacy on pain and agitation, assessed through the recently validated Italian Mobilization-Observation-Behavior-Intensity-Dementia and the Cohen-Mansfield Agitation Inventory. The secondary endpoint is the evaluation of efficacy duration after wash-out and the assessment of quality of life through the DEMQOL. Any adverse events will be reported. The results undergo statistical analysis plan. NACTOPAISD might provide rationale for a translational safer pain and agitation treatment in severe dementia. It is approved by Calabria Region Ethics Committee and follows the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) and the Consolidated Standards of Reporting Trials (CONSORT) statements.
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Cannabidiol , Dolor Crónico , Demencia , Dronabinol , Agitación Psicomotora , Anciano , Cannabidiol/administración & dosificación , Cannabidiol/efectos adversos , Dolor Crónico/tratamiento farmacológico , Dolor Crónico/etiología , Demencia/complicaciones , Demencia/tratamiento farmacológico , Método Doble Ciego , Dronabinol/administración & dosificación , Dronabinol/efectos adversos , Combinación de Medicamentos , Humanos , Vaporizadores Orales , Agitación Psicomotora/tratamiento farmacológico , Agitación Psicomotora/etiología , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
The 97% of dementia patients develops fluctuant neuropsychiatric symptoms often related to under-diagnosed and unrelieved pain. Up to 80% severe demented nursing home residents experiences chronic pain due to age-related comorbidities. Patients lacking self-report skills risk not to be appropriately treated for pain. Mobilization-Observation-Behavior-Intensity-Dementia (MOBID2) is the sole pain scale to consider the frequent co-occurrence of musculoskeletal and visceral pain and to unravel concealed pain through active guided movements. Accordingly, the Italian real-world setting can benefit from its translation and validation. This clinical study provides a translated, adapted and validated version of the MOBID2, the Italian I-MOBID2. The translation, adaptation and validation of the scale for non-verbal, severe demented patients was conducted according to current guidelines in a cohort of 11 patients over 65 with mini-mental state examination ≤ 12. The I-MOBID2 proves: good face and scale content validity index (0.89); reliable internal consistency (Cronbach's α = 0.751); good to excellent inter-rater (Intraclass correlation coefficient, and test-retest (ICC = 0.902) reliability. The construct validity is high (Rho = 0.748 p < 0.05 for 11 patients, Spearman rank order correlation of the overall pain intensity score with the maximum item score of I-MOBID2 Part 1; rho=0.895 p < 0.01 for 11 patients, for the overall pain intensity score with the maximum item score of I-MOBID2 Part 2) and a good rate of inter-rater and test-retest agreement was demonstrated by Cohen's K = 0.744. The average execution time is of 5.8 min, thus making I-MOBID2 a useful tool suitable also for future development in community setting with administration by caregivers.
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Dolor Crónico , Demencia , Dolor Crónico/psicología , Demencia/terapia , Humanos , Dimensión del Dolor , Psicometría , Reproducibilidad de los Resultados , Encuestas y CuestionariosRESUMEN
BACKGROUND: Purpose of the present systematic review is to investigate preclinical evidence in favor of the working hypothesis of efficacy of cannabinoids in ocular pain treatment. METHODS: Literature search includes the most relevant repositories for medical scientific literature from inception until November, 24 2021. Data collection and selection of retrieved records adhere to PRISMA criteria. RESULTS: In agreement with a priori established protocol the search retrieved 2471 records leaving 479 results after duplicates removal. Eleven records result from title and abstract screening to meet the inclusion criteria; only 4 results are eligible for inclusion in the qualitative synthesis impeding meta-analysis. The qualitative analysis highlights the antinociceptive and anti-inflammatory efficacy of Δ8-tetrahydrocannabinol, cannabidiol and its derivative HU-308 and of new racemic CB1 allosteric ligand GAT211 and its enantiomers GAT228 and GAT229. Moreover, CB2R agonists RO6871304 and RO6871085 and CB2R ligand HU910 provide evidence of anti-inflammatory efficacy. CB2 agonist HU308 reduces of 241% uveitis-induced leukocyte adhesion and changes lipidome profile. Methodological and design issues raise concern of risk of bias and the amount of studies is too small for generalization. Furthermore, the ocular pain model used can resemble only inflammatory but not neuropathic pain. CONCLUSIONS: The role of the endocannabinoid system in ocular pain is underinvestigated, since only two studies assessing the effects of cannabinoid receptors modulators on pain behavior and other two on pain-related inflammatory processes are found. Preclinical studies investigating the efficacy of cannabinoids in ocular inflammatory and neuropathic pain models are needed to pave the way for clinical translation.
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Agonistas de Receptores de Cannabinoides/farmacología , Cannabinoides/farmacología , Dolor Ocular/tratamiento farmacológico , Uveítis/tratamiento farmacológico , Animales , Antiinflamatorios/farmacología , Cannabidiol/farmacología , Modelos Animales de Enfermedad , Dronabinol/farmacología , Evaluación Preclínica de Medicamentos , Leucocitos/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , RoedoresRESUMEN
The ternary AMnBi_{2} (A is alkaline as well as rare-earth atom) materials provide an arena for investigating the interplay between low-dimensional magnetism of the antiferromagnetic MnBi layers and the electronic states in the intercalated Bi layers, which harbor relativistic fermions. Here, we report on a comprehensive study of the optical properties and magnetic torque response of Ca_{1-x}Na_{x}MnBi_{2}. Our findings give evidence for a spin canting occurring at T_{s}â¼50-100 K. With the support of first-principles calculations we establish a direct link between the spin canting and the reconstruction of the electronic band structure, having immediate implications for the spectral weight reshuffling in the optical response, signaling a partial gapping of the Fermi surface, and the dc transport properties below T_{s}.
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Eptinezumab (ALD-403) is a genetically engineered humanized IgG1kappa directed towards calcitonin gene-related peptide (CGRP), currently in late-stage clinical development. Eptinezumab targets the pathway of CGRP, importantly implicated in migraine pathophysiology, and may represent the first-to-market infusion therapy for migraine prevention. The background for its approval consists in preclinical data and clinical trials. Here, we provide a comprehensive review of molecular pharmacology, pharmacokinetics, metabolism, efficacy and safety investigated in the preclinical and clinical studies, with insight on possible future directions.
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Anticuerpos Monoclonales Humanizados/uso terapéutico , Antagonistas del Receptor Peptídico Relacionado con el Gen de la Calcitonina/uso terapéutico , Trastornos Migrañosos/tratamiento farmacológico , HumanosRESUMEN
SrRuO3 (SRO) is a perovskite increasingly used in oxide-based electronics both for its intrinsic metallicity, which remains unaltered in thin films and for the ease of deposition on dielectric perovskites like SrTiO3, (STO) to implement SRO/STO microcapacitors and other devices. In order to test the reliability of SRO/STO also as high-current on-chip conductor, when the SRO dimensions are pushed to the nanoscale, here we have measured the electrodynamic properties of arrays of nanoribbons, fabricated by lithography starting from an ultrathin film of SRO deposited on a STO substrate. The nanoribbons are 6 or 4 nm thick, 400, 200 and 100 nm wide and 5 mm long. The measurements have been performed by infrared spectroscopy, a non-contact weakly perturbing technique which also allows one to separately determine the carrier density and their scattering rate or mobility. Far-infrared reflectivity spectra have been analyzed by Rigorous Coupled-Wave Analysis (RCWA) and by an Effective Medium Theory, obtaining consistent results. With the radiation polarized along the nanoribbons, we obtain a carrier density similar to that of a flat film used as reference, which in turn is similar to that of bulk SRO. Moreover, in the nanoribbons the carrier scattering rate is even smaller than in the unpatterned film by about a factor of 2. This shows that the transport properties of SRO deposited on STO remain at least unaltered down to nanometric dimensions, with interesting perspectives for implementing on-chip nano-interconnects in an oxide-based electronics. When excited in the perpendicular direction, the nanoribbons appear instead virtually transparent to the radiation field, as predicted by RCWA.
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In complementary medicine, aromatherapy uses essential oils to improve agitation and aggression observed in dementia, mood, depression, anxiety and chronic pain. Preclinical research studies have reported that the essential oil obtained from bergamot (BEO) fruit (Citrus bergamia, Risso) modifies normal and pathological synaptic plasticity implicated, for instance, in nociceptive and neuropathic pain. Interestingly, recent results indicated that BEO modulates sensitive perception of pain in different models of nociceptive, inflammatory and neuropathic pain modulating endogenous systems. Thus, local administration of BEO inhibited the nociceptive behavioral effect induced by intraplantar injection of capsaicin or formalin in mice. Similar effects were observed with linalool and linalyl acetate, major volatile components of the phytocomplex, Pharmacological studies showed that the latter effects are reversed by local or systemic pretreatment with the opioid antagonist naloxone hydrochloride alike with naloxone methiodide, high affinity peripheral µ-opioid receptor antagonist. These results and the synergistic effect observed following systemic or intrathecal injection of an inactive dose of morphine with BEO or linalool indicated an activation of peripheral opioid system. Recently, in neuropathic pain models systemic or local administration of BEO or linalool induced antiallodynic effects. In particular, in partial sciatic nerve ligation (PSNL) model, intraplantar injection of the phytocomplex or linalool in the ipsilateral hindpaw, but not in the contralateral, reduced PSNL-induced extracellularsignal- regulated kinase (ERK) activation and mechanical allodynia. In neuropathic pain high doses of morphine are needed to reduce pain. Interestingly, combination of inactive doses of BEO or linalool with a low dose of morphine induced antiallodynic effects in mice. Peripheral cannabinoid and opioid systems appear to be involved in the antinociception produced by intraplantar injection of ß -caryophyllene, present in different essential oils including BEO. The data gathered so far indicate that the essential oil of bergamot is endowed with antinociceptive and antiallodynic effects and contribute to form the rational basis for rigorous testing of its efficacy in complementary medicine.
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Dolor Crónico/tratamiento farmacológico , Terapias Complementarias , Aceites de Plantas/uso terapéutico , HumanosRESUMEN
The pathophysiological processes implicated in ischemic brain damage are strongly affected by an inflammatory reaction characterized by activation of immune cells and release of soluble mediators, including cytokines and chemokines. The pro-inflammatory cytokine interleukin (IL)-1ß has been implicated in ischemic brain injury, however, to date, the mechanisms involved in the maturation of this cytokine in the ischemic brain have not been completely elucidated. We have previously suggested that matrix metalloproteinases (MMPs) may be implicated in cytokine production under pathological conditions. Here, we demonstrate that significant elevation of IL-1ß occurs in the cortex as early as 1h after the beginning of reperfusion in rats subjected to 2-h middle cerebral artery occlusion (MCAo). At this early stage, we observe increased expression of IL-1ß in pericallosal astroglial cells and in cortical neurons and this latter signal colocalizes with elevated gelatinolytic activity. By gel zymography, we demonstrate that the increased gelatinolytic signal at 1-h reperfusion is mainly ascribed to MMP2. Thus, MMP2 seems to contribute to early brain elevation of IL-ß after transient ischemia and this mechanism may promote damage since pharmacological inhibition of gelatinases by the selective MMP2/MMP9 inhibitor V provides neuroprotection in rats subjected to transient MCAo.
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Corteza Cerebral/fisiopatología , Infarto de la Arteria Cerebral Media/fisiopatología , Interleucina-1beta/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Neuronas/fisiología , Daño por Reperfusión/fisiopatología , Animales , Astrocitos/efectos de los fármacos , Astrocitos/fisiología , Corteza Cerebral/efectos de los fármacos , Ensayo de Inmunoadsorción Enzimática , Gelatina/metabolismo , Inmunohistoquímica , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Masculino , Metaloproteinasa 9 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz/farmacología , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Distribución Aleatoria , Ratas Wistar , Daño por Reperfusión/tratamiento farmacológico , Factores de TiempoRESUMEN
The evolution of ischemic brain damage is strongly affected by an inflammatory reaction that involves soluble mediators, such as cytokines and chemokines, and specialized cells activated locally or recruited from the periphery. The immune system affects all phases of the ischemic cascade, from the acute intravascular reaction due to blood flow disruption, to the development of brain tissue damage, repair and regeneration. Increased endothelial expression of adhesion molecules and blood-brain barrier breakdown promotes extravasation and brain recruitment of blood-borne cells, including macrophages, neutrophils, dendritic cells and T lymphocytes, as demonstrated both in animal models and in human stroke. Nevertheless, most anti-inflammatory approaches showing promising results in experimental stroke models failed in the clinical setting. The lack of translation may reside in the redundancy of most inflammatory mediators, exerting both detrimental and beneficial functions. Thus, this review is aimed at providing a better understanding of the dualistic role played by each component of the inflammatory/immune response in relation to the spatio-temporal evolution of ischemic stroke injury.
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Accidente Cerebrovascular/inmunología , Animales , Antiinflamatorios/uso terapéutico , Humanos , Inflamación/inmunología , Transducción de Señal , Accidente Cerebrovascular/tratamiento farmacológico , Linfocitos T/inmunologíaRESUMEN
Activation of RAGE (receptor for advanced glycation endproducts) and of its subtypes may play a role in neuronal damage and neuroinflammation associated with brain ischemia, though the underlying mechanisms remain unclear. In this study, we have examined by Western blotting the expression of RAGE isoforms in the cerebral cortex and striatum of Wistar rats subjected to transient (1 or 2 h) middle cerebral artery occlusion (tMCAo). The findings show that the full-length RAGE (~50 kDa) and its isoforms in the 26-43 kDa range are significantly decreased in the ischemic cortex, but not in the striatum, after 1 and 2 h tMCAo when compared to the sham group. By contrast, in the striatum, ischemia-reperfusion injury caused a significant increase of full-length RAGE and its isoforms in the 72-100 kDa range. We also investigated the soluble form of RAGE, which was significantly decreased in the plasma of rats subjected to transient or permanent MCAo. In conclusion, the present data demonstrate that regional brain expression of RAGE is differentially affected by tMCAo in rat. These modifications are accompanied by a decrease in the plasma levels of soluble RAGE, thereby suggesting a potential role for soluble RAGE as a peripheral biomarker of focal ischemia.
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Ataque Isquémico Transitorio/metabolismo , Isoformas de Proteínas/metabolismo , Receptores Inmunológicos/metabolismo , Animales , Western Blotting , Técnica del Anticuerpo Fluorescente , Ataque Isquémico Transitorio/sangre , Masculino , Isoformas de Proteínas/sangre , Ratas , Ratas Wistar/sangre , Receptor para Productos Finales de Glicación AvanzadaRESUMEN
In addition to its effects in the hypothalamus to control body weight, leptin is involved in the regulation of neuronal function, development and survival. Recent findings have highlighted the neuroprotective effects of leptin against ischemic brain injury; however, to date, little is known about the role performed by the signal transducer and activator of transcription (STAT)-3, a major mediator of leptin receptor transduction pathway in the brain, in the beneficial effects of the hormone. Our data demonstrate that systemic acute administration of leptin produces neuroprotection in rats subjected to permanent middle cerebral artery occlusion (MCAo), as revealed by a significant reduction of the brain infarct volume and neurological deficit up to 7 days after the induction of ischemia. By combining a subcellular fractionation approach with immunohistofluorescence, we observe that neuroprotection is associated with a cell type-specific modulation of STAT3 phosphorylation in the ischemic cortex. The early enhancement of nuclear phospho-STAT3 induced by leptin in the astrocytes of the ischemic penumbra may contribute to a beneficial effect of these cells on the evolution of tissue damage. In addition, the elevation of phospho-STAT3 induced by leptin in the neurons after 24 h MCAo is associated with an increased expression of tissue inhibitor of matrix metalloproteinases-1 in the cortex, suggesting its possible involvement to the neuroprotection produced by the adipokine.
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Isquemia Encefálica/patología , Leptina/metabolismo , Neuronas/metabolismo , Factor de Transcripción STAT3/metabolismo , Adipoquinas/metabolismo , Animales , Encéfalo/citología , Isquemia Encefálica/metabolismo , Modelos Animales de Enfermedad , Inmunohistoquímica , Leptina/farmacología , Masculino , Neuronas/efectos de los fármacos , Fosforilación , Ratas , Ratas Wistar , Inhibidor Tisular de Metaloproteinasa-1/metabolismoRESUMEN
Autophagy is the major intracellular degradation pathway that regulates long-lived proteins and organelles turnover. This process occurs at basal levels in all cells but it is rapidly upregulated in response to starvation and cellular stress. Although being recently implicated in neurodegeneration, it remains still unclear whether autophagy has a detrimental or protective role. In this study, we investigated the dynamics of the autophagic process in retinal tissue that has undergone transient ischemia, an experimental model that recapitulates features of ocular pathologies, including glaucoma, anterior ischemic optic neuropathy and retinal vessels occlusion. Retinal ischemia, induced in adult rats by increasing the intraocular pressure, was characterized by a reduction in the phosphatidylethanolamine-modified form of LC3 (LC3II) and by a significant decrease in Beclin-1. The latter event was associated with a proteolytic cleavage of Beclin-1, leading to the accumulation of a 50-kDa fragment. This event was prevented by intravitreal treatment with the non-competitive N-methyl-D-aspartate antagonist MK801 and calpain inhibitors or by calpain knockdown. Blockade of autophagy by pharmacological inhibition or Beclin-1 silencing in RGC-5 increased cell death, suggesting a pro-survival role of the autophagic process in this neuronal cell type. Altogether, our results provide original evidence for calpain-mediated cleavage of Beclin-1 and deregulation of basal autophagy in the rat retina that has undergone ocular ischemia/reperfusion injury.
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Proteínas Reguladoras de la Apoptosis/metabolismo , Autofagia , Calpaína/metabolismo , Riñón/irrigación sanguínea , Daño por Reperfusión/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/genética , Beclina-1 , Calpaína/genética , Línea Celular , Modelos Animales de Enfermedad , Humanos , Isquemia/genética , Isquemia/metabolismo , Riñón/metabolismo , Masculino , Procesamiento Proteico-Postraduccional , Ratas , Ratas Wistar , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Daño por Reperfusión/genética , Daño por Reperfusión/fisiopatologíaRESUMEN
Loss of retinal ganglion cells occurs in a variety of pathological conditions, including central retinal artery occlusion, diabetes and glaucoma. Using an experimental model of retinal ischemia induced by transiently raise the intraocular pressure (IOP), In this study, we report the original observation that ischemic retinal ganglion cells death is associated with the transient deactivation of the pro-survival kinase Akt and activation of GSK-3beta followed, during reperfusion, by a longer lasting, PI3K-dependent, activation of Akt and phosphorylation of GSK-3beta. Under these experimental conditions, retinal ischemia induced the expression of Bad, a pro-apoptotic protein, member of the Bcl-2 family. The detrimental effects yielded by the ischemic stimulus were minimized by intravitreal administration of the NMDA receptor antagonist, MK801, that reduced the expression of Bad and significantly increased Akt phosphorylation. In conclusion, our present results contribute to unravel the mechanisms underlying retinal damage by high IOP-induced transient ischemia in rat. In addition, these data implicate the pro-survival PI3K/Akt pathway and the observed reduced expression of Bad in the neuroprotection afforded by MK801.
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Receptores de N-Metil-D-Aspartato/fisiología , Daño por Reperfusión/fisiopatología , Enfermedades de la Retina/fisiopatología , Transducción de Señal/fisiología , Análisis de Varianza , Androstadienos/farmacología , Animales , Muerte Celular/fisiología , Cromonas/farmacología , Maleato de Dizocilpina/farmacología , Inhibidores Enzimáticos/farmacología , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Presión Intraocular/fisiología , Isquemia/complicaciones , Isquemia/fisiopatología , Masculino , Morfolinas/farmacología , Proteína Oncogénica v-akt/metabolismo , Fosfohidrolasa PTEN/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Wistar , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Daño por Reperfusión/etiología , Enfermedades de la Retina/complicaciones , Enfermedades de la Retina/patología , Serina/metabolismo , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Wortmanina , Proteína Letal Asociada a bcl/metabolismoRESUMEN
Matrix metalloproteinases (MMPs) have been implicated in the pathophysiology of ischemic stroke. In particular, the gelatinases MMP-2 and MMP-9 contribute to disruption of the blood-brain barrier and hemorrhagic transformation following ischemic injury. In addition to extracellular matrix degradation, MMPs may directly regulate neuronal cell death through mechanisms that are not completely understood. Here we describe the spatio-temporal distribution of activated MMP-2 and MMP-9 in the brain of rats subjected to 2 h middle cerebral artery occlusion (MCAo) followed by different periods of reperfusion (15 min, 2 h, 6 h and 22 h). By in situ zymography we have observed that gelatinases become activated 15 min and 2 h after the beginning of reperfusion in the ischemic core and penumbra, respectively. In situ zymography signal broadly co-localized with NeuN-positive cells, thus suggesting that proteolysis mainly occurs in neurons. Gelatinolytic activity was mainly detected in cell nuclei, marginally appearing in the cytosol only at later stages following the insult; we did not detect variations in gelatinolysis in the extracellular matrix. Finally, we report that pharmacological inhibition of MMPs by N-[(2R)-2-(hydroxamidocarbonyl-methyl)-4-methylpenthanoyl]-L-tryptophan methylamide (GM6001) significantly reduces brain infarct volume induced by transient MCAo. Taken together our data underscore the crucial role of gelatinases during the early stages of reperfusion and further extend previous observations documenting the detrimental role of these enzymes in the pathophysiology of brain ischemia.
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Encéfalo/enzimología , Infarto de la Arteria Cerebral Media/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Neuronas/enzimología , Animales , Encéfalo/efectos de los fármacos , Núcleo Celular/enzimología , Citoplasma/enzimología , Dipéptidos/farmacología , Activación Enzimática/fisiología , Matriz Extracelular/enzimología , Inmunohistoquímica , Masculino , Metaloproteinasa 2 de la Matriz/efectos de los fármacos , Metaloproteinasa 9 de la Matriz/efectos de los fármacos , Neuronas/efectos de los fármacos , Inhibidores de Proteasas/farmacología , Ratas , Ratas WistarRESUMEN
Abnormal expression of matrix metalloproteinases (MMPs) has been implicated in the pathophysiology of neuroinflammatory processes that accompany most central nervous system disease. In particular, early upregulation of the gelatinases MMP-2 and MMP-9 has been shown to contribute to disruption of the blood-brain barrier and to death of neurons in ischemic stroke. In situ zymography reveals a significant increase in gelatinolytic MMPs activity in the ischemic brain hemisphere after 2-h middle cerebral artery occlusion (MCAo) followed by 2-h reperfusion in rat. Accordingly, gel zymography demonstrates that expression and activity of MMP-2 and MMP-9 are enhanced in cortex and striatum ipsilateral to the ischemic insult. The latter effect appears to be instrumental for development of delayed brain damage since administration of a broad spectrum, highly specific MMPs inhibitor, GM6001, but not by its negative control, results in a significant (50%) reduction in ischemic brain volume. Increased gelatinase activity in the ischemic cortex coincides with elevation (166% vs sham) of mature interleukin-1beta (IL-1beta) after 2-h reperfusion and this does not appear to implicate a caspase-1-dependent processing of pro(31kDa)-IL-1beta to yield mature (17kDa) IL-1beta. More importantly, when administered at a neuroprotective dose GM6001 abolishes the early IL-1beta increase in the ischemic cortex and reduces the cleavage of the cytokine proform supporting the deduction that MMPs may initiate IL-1beta processing. In conclusion, development of tissue damage that follows transient ischemia implicates a crucial interplay between MMPs and mediators of neuroinflammation (e.g., IL-1beta), and this further underscores the therapeutic potential of MMPs inhibitors in the treatment of stroke.
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Isquemia Encefálica/metabolismo , Mediadores de Inflamación/metabolismo , Metaloproteinasas de la Matriz/biosíntesis , Daño por Reperfusión/enzimología , Animales , Western Blotting , Isquemia Encefálica/patología , Caspasa 1/metabolismo , Fluorometría , Gelatina/metabolismo , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patología , Interleucina-1beta/biosíntesis , Masculino , Metaloproteinasa 2 de la Matriz/biosíntesis , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/biosíntesis , Metaloproteinasa 9 de la Matriz/genética , Ratas , Ratas Wistar , Regulación hacia Arriba/fisiologíaRESUMEN
Neuroprotection exerted by 17beta-estradiol (17beta-E(2)) has been widely investigated in animal models of acute cerebral ischemia. Estrogens interact with intracellular receptors (ERalpha and ERbeta) to modulate the transcription of target genes, including those implicated in neuronal survival. Neuroprotection may also occur via interaction with ER-like membrane receptors mediating rapid, non-genomic, actions or via receptor-independent mechanisms. There is also evidence that blockade of inflammatory factors may represent an important mechanism involved in estrogenic neuroprotection. Here we investigate whether reduced brain damage by acute pharmacological treatment with 17beta-E(2) in male rats subjected to transient (2h) middle cerebral artery occlusion (tMCAo) involves modulation of interleukin-1beta (IL-1beta), a proinflammatory cytokine strongly implicated in the pathophysiology of ischemic stroke. Administration of 17beta-E(2) (0.2mg/kg, i.p., 1h before tMCAo) results in significant reduction of brain infarct volume, and this is reverted by the ER antagonist ICI 182,780 (0.25mg/kg, i.p.) administered 1h before 17beta-E(2). Two hours MCAo followed by 2-h reperfusion results in a significant, threefold increase of IL-1beta levels in the cortical tissue ipsilateral to the ischemic damage. Interestingly, a pretreatment with a neuroprotective dose of 17beta-E(2) attenuates the cytokine elevation and this appears to occur through ER activation. In addition, neuroprotection by 17beta-E(2) is accompanied by reduced cytochrome c translocation both in the striatum and in the cortex as revealed by Western blotting 3h after reperfusion. In conclusion, we report the original observation that neuroprotection exerted by 17beta-E(2) in a rat model of transient focal brain ischemia is accompanied by reduced cytochrome c translocation to the cytosol and involves early modulation of IL-1beta production.
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Estradiol/farmacología , Infarto de la Arteria Cerebral Media/prevención & control , Interleucina-1beta/fisiología , Fármacos Neuroprotectores , Animales , Western Blotting , Isquemia Encefálica/patología , Citocromos c/metabolismo , Citosol/efectos de los fármacos , Citosol/enzimología , Ensayo de Inmunoadsorción Enzimática , Estradiol/análogos & derivados , Antagonistas de Estrógenos/farmacología , Fulvestrant , Infarto de la Arteria Cerebral Media/patología , Interleucina-1beta/biosíntesis , Masculino , Ratas , Ratas Wistar , Receptores de Estrógenos/antagonistas & inhibidores , Fracciones Subcelulares/efectos de los fármacos , Fracciones Subcelulares/patologíaRESUMEN
Recent studies support a role for excitotoxicity in the development of retinal ganglion cell (RGC) damage in subjects suffering from glaucoma. Coenzyme Q10 (CoQ10), an essential cofactor of the electron transport chain, has been reported to afford neuroprotection, preventing the formation of the mitochondrial permeability transition pore. Using an established animal model of retinal ischemia/reperfusion here, we show that synaptic glutamate increases at 130min from beginning of reperfusion and delayed apoptosis in the RGC layer is seen at 24h. Intraocular administration of CoQ10 minimizes glutamate increase and affords neuroprotection, suggesting that oxidative stress and energy failure might be implicated in the mechanisms of RGC death.
Asunto(s)
Presión Intraocular/fisiología , Isquemia/patología , Enfermedades de la Retina/prevención & control , Ubiquinona/análogos & derivados , Administración Tópica , Animales , Coenzimas/administración & dosificación , Coenzimas/uso terapéutico , Ácido Glutámico/toxicidad , Etiquetado Corte-Fin in Situ , Masculino , Microdiálisis , Ratas , Ratas Wistar , Enfermedades de la Retina/patología , Células Ganglionares de la Retina/efectos de los fármacos , Células Ganglionares de la Retina/patología , Ubiquinona/administración & dosificación , Ubiquinona/uso terapéuticoRESUMEN
Transient focal ischemia caused by middle cerebral artery occlusion (MCAo) produces apoptotic cell death in the penumbra area. Bcl-2 is a protooncogene that plays a major antiapoptotic role, at the cellular level, by counteracting the activation of apoptosis effectors, that is, caspases. It has been suggested that nitroglycerin (NTG), a nitric oxide donor, reduces ischemia/reperfusion-induced brain damage via the inhibition of caspase activity and NMDA receptor. In this chapter, we evaluated the protective effects of NTG against cerebral damage caused by transient (2h) MCAo (tMCAo) focusing our interest on the potential effects on Bcl-2 expression. Male Wistar rats were administered intraperitoneally (i.p.) with NTG (10mg/kg) or vehicle (PEG, 1ml/kg) 20min before the induction of MCAo by intraluminal silicon-coated filament (0.37-mm diameter). Cerebral infarct volume was measured 22h after reperfusion, while cortical Bcl-2 expression was evaluated at the end of 2-h MCAo (without reperfusion) and at 5h of reperfusion. The results show significant reduction of the infarct volume in rats preinjected with NTG, as compared to the vehicle group. After 2h of occlusion, no significant difference was seen in Bcl-2 expression in the ipsilateral and contralateral cortex of either experimental groups (NTG and vehicle). However, 5h after reperfusion, a significant increase of Bcl-2 expression was detected in the damaged cortex of control rats, probably reflecting a compensatory response aiming at counteracting the cell death process; this increase was absent in the NTG-treated rats. These data, while confirming the neuroprotective effect of NTG in an in vivo ischemia/reperfusion model, seem to suggest that the drug may act by downsizing the complex chain of events underlying apoptosis activation and consequent activation of antiapoptotic responses.