Coordination between proteasome impairment and caspase activation leading to TAU pathology: neuroprotection by cAMP

Neurofibrillary tangles (NFTs) are hallmarks of Alzheimer’s disease (AD). The main component of NFTs is TAU, a highly soluble microtubule-associated protein. However, when TAU is cleaved at Asp421 by caspases it becomes prone to aggregation leading to NFTs. What triggers caspase activation resulting in TAU cleavage remains unclear. We investigated in rat cortical neurons a potential coordination between proteasome impairment and caspase activation. We demonstrate that upon proteasome inhibition, the early accumulation of detergent-soluble ubiquitinated (SUb) proteins paves the way to caspase activation and TAU pathology. This occurs with two drugs that inhibit the proteasome by different means: the product of inflammation prostaglandin J2 (PGJ2) and epoxomicin. Our results pinpoint a critical early event, that is, the buildup of SUb proteins that contributes to caspase activation, TAU cleavage, TAU/Ub-protein aggregation and neuronal death. Furthermore, to our knowledge, we are the first to demonstrate that elevating cAMP in neurons with dibutyryl-cAMP (db-cAMP) or the lipophilic peptide PACAP27 prevents/ diminishes caspase activation, TAU cleavage and neuronal death induced by PGJ2, as long as these PGJ2-induced changes are moderate. db-cAMP also stimulated proteasomes, and mitigated proteasome inhibition induced by PGJ2. We propose that targeting cAMP/PKA to boost proteasome activity in a sustainable manner could offer an effective approach to avoid early accumulation of SUb proteins and later caspase activation, and TAU cleavage, possibly preventing/delaying AD neurodegeneration

Subchronic infusion of the product of inflammation prostaglandin J2 models sporadic Parkinson\u27s disease in mice

Background Chronic neuroinflammation is implicated in Parkinson\u27s disease (PD). Inflammation involves the activation of microglia and astrocytes that release high levels of prostaglandins. There is a profound gap in our understanding of how cyclooxygenases and their prostaglandin products redirect cellular events to promote PD neurodegeneration. The major prostaglandin in the mammalian brain is prostaglandin D2, which readily undergoes spontaneous dehydration to generate the bioactive cyclopentenone prostaglandins of the J2 series. These J2 prostaglandins are highly reactive and neurotoxic products of inflammation shown in cellular models to impair the ubiquitin/proteasome pathway and cause the accumulation of ubiquitinated proteins. PD is a disorder that exhibits accumulation of ubiquitinated proteins in neuronal inclusions (Lewy bodies). The role of J2 prostaglandins in promoting PD neurodegeneration has not been investigated under in vivo conditions. Methods We addressed the neurodegenerative and behavioral effects of the administration of prostaglandin J2 (PGJ2) simultaneously into the substantia nigra/striatum of adult male FVB mice by subchronic microinjections. One group received unilateral injections of DMSO (vehicle, n = 6) and three groups received PGJ2 [3.4 μg or 6.7 μg (n = 6 per group) or 16.7 μg (n = 5)] per injection. Immunohistochemical and behavioral analyses were applied to assess the effects of the subchronic PGJ2 microinfusions. Results Immunohistochemical analysis demonstrated a PGJ2 dose-dependent significant and selective loss of dopaminergic neurons in the substantia nigra while the GABAergic neurons were spared. PGJ2 also triggered formation of aggregates immunoreactive for ubiquitin and α-synuclein in the spared dopaminergic neurons. Moreover, PGJ2 infusion caused a massive microglia and astrocyte activation that could initiate a deleterious cascade leading to self-sustained progressive neurodegeneration. The PGJ2-treated mice also exhibited locomotor and posture impairment. Conclusion Our studies establish the first model of inflammation in which administration of an endogenous highly reactive product of inflammation, PGJ2, recapitulates key aspects of PD. Our novel PGJ2-induced PD model strongly supports the view that localized and chronic production of highly reactive and neurotoxic prostaglandins, such as PGJ2, in the CNS could be an integral component of inflammation triggered by insults evoked by physical, chemical or microbial stimuli and thus establishes a link between neuroinflammation and PD neurodegeneration

Neuroinflammation and J2 Prostaglandins: Linking Impairment of the Ubiquitin-Proteasome Pathway and Mitochondria to Neurodegeneration

The immune response of the CNS is a defense mechanism activated upon injury to initiate repair mechanisms while chronic over-activation of the CNS immune system (termed neuroinflammation) may exacerbate injury. The latter is implicated in a variety of neurological and neurodegenerative disorders such as Alzheimer and Parkinson diseases, amyotrophic lateral sclerosis, multiple sclerosis, traumatic brain injury, HIV dementia, and prion diseases. Cyclooxygenases (COX-1 and COX-2), which are key enzymes in the conversion of arachidonic acid into bioactive prostanoids, play a central role in the inflammatory cascade. J2 prostaglandins are endogenous toxic products of cyclooxygenases, and because their levels are significantly increased upon brain injury, they are actively involved in neuronal dysfunction induced by pro-inflammatory stimuli. In this review, we highlight the mechanisms by which J2 prostaglandins (1) exert their actions, (2) potentially contribute to the transition from acute to chronic inflammation and to the spreading of neuropathology, (3) disturb the ubiquitin-proteasome pathway and mitochondrial function, and (4) contribute to neurodegenerative disorders such as Alzheimer and Parkinson diseases, and amyotrophic lateral sclerosis, as well as stroke, traumatic brain injury (TBI), and demyelination in Krabbe disease. We conclude by discussing the therapeutic potential of targeting the J2 prostaglandin pathway to prevent/delay neurodegeneration associated with neuroinflammation. In this context, we suggest a shift from the traditional view that cyclooxygenases are the most appropriate targets to treat neuroinflammation, to the notion that J2 prostaglandin pathways and other neurotoxic prostaglandins downstream from cyclooxygenases, would offer significant benefits as more effective therapeutic targets to treat chronic neurodegenerative diseases, while minimizing adverse side effects

The Ubiquitin-Proteasome System: Potential Therapeutic Targets for Alzheimer’s Disease and Spinal Cord Injury

The ubiquitin-proteasome system (UPS) is a crucial protein degradation system in eukaryotes. Herein, we will review advances in the understanding of the role of several proteins of the UPS in Alzheimer’s disease (AD) and functional recovery after spinal cord injury (SCI). The UPS consists of many factors that include E3 ubiquitin ligases, ubiquitin hydrolases, ubiquitin and ubiquitin-like molecules, and the proteasome itself. An extensive body of work links UPS dysfunction with AD pathogenesis and progression. More recently, the UPS has been shown to have vital roles in recovery of function after SCI. The ubiquitin hydrolase (Uch-L1) has been proposed to increase cellular levels of mono-ubiquitin and hence to increase rates of protein turnover by the UPS. A low Uch-L1 level has been linked with Ab accumulation in AD and reduced neuroregeneration after SCI. One likely mechanism for these beneficial effects of Uch-L1 is reduced turnover of the PKA regulatory subunit and consequently, reduced signaling via CREB. The neuron-specific F-box protein Fbx2 ubiquitinates b-secretase thus targeting it for proteasomal degradation and reducing generation of Ab. Both Uch-L1 and Fbx2 improve synaptic plasticity and cognitive function in mouse AD models. The role of Fbx2 after SCI has not been examined, but abolishing ß-secretase reduces neuronal recovery after SCI, associated with reduced myelination. UBB+1, which arises through a frame-shift mutation in the ubiquitin gene that adds 19 amino acids to the C-terminus of ubiquitin, inhibits proteasomal function and is associated with increased neurofibrillary tangles in patients with AD, Pick’s disease and Down’s syndrome. These advances in understanding of the roles of the UPS in AD and SCI raise new questions but, also, identify attractive and exciting targets for potential, future therapeutic interventions

Prostaglandin D2/J2 signaling pathway in a rat model of neuroinflammation displaying progressive parkinsonian-like pathology: potential novel therapeutic targets

Background: Prostaglandins are products of the cyclooxygenase pathway, which is implicated in Parkinson’s disease (PD). Limited knowledge is available on mechanisms by which prostaglandins contribute to PD neurodegeneration. To address this gap, we focused on the prostaglandin PGD2/J2 signaling pathway, because PGD2 is the most abundant prostaglandin in the brain, and the one that increases the most under pathological conditions. Moreover, PGJ2 is spontaneously derived from PGD2. Methods: In this study, we determined in rats the impact of unilateral nigral PGJ2-microinfusions on COX-2, lipocalin-type PGD2 synthase (L-PGDS), PGD2/J2 receptor 2 (DP2), and 15 hydroxyprostaglandin dehydrogenase (15-PGDH). Nigral dopaminergic (DA) and microglial distribution and expression levels of these key factors of the prostaglandin D2/J2 pathway were evaluated by immunohistochemistry. PGJ2-induced motor deficits were assessed with the cylinder test. We also determined whether oral treatment with ibuprofen improved the PD-like pathology induced by PGJ2. Results: PGJ2 treatment induced progressive PD-like pathology in the rats. Concomitant with DA neuronal loss in the substantia nigra pars compacta (SNpc), PGJ2-treated rats exhibited microglia and astrocyte activation and motor deficits. In DA neurons, COX-2, L-PGDS, and 15-PGDH levelsincreased significantly in PGJ2-treated rats compared to controls, while DP2 receptor levels were unchanged. In microglia, DP2 receptors were basically non-detectable, while COX-2 and L-PGDS levels increased upon PGJ2-treatment, and 15-PGDH remained unchanged. 15-PGDH was also detected in oligodendrocytes. Notably, ibuprofen prevented most PGJ2-induced PD-like pathology. Conclusions: The PGJ2-induced rat model develops progressive PD pathology, which is a hard-to-mimic aspect of this disorder. Moreover, prevention of most PGJ2-induced PD-like pathology with ibuprofen suggests a positive feedback mechanism between PGJ2 and COX-2 that could lead to chronic neuroinflammation. Notably, this is the first study that analyzes the nigral dopaminergic and microglial distribution and levels of factors of the PGD2/J2 signaling pathway in rodents. Our findings support the notions that upregulation of COX-2 and L-PGDS may be important in the PGJ2 evoked PD-like pathology, and that neuronal DP2 receptor antagonists and L-PGDS inhibitors may be novel pharmacotherapeutics to relieve neuroinflammation-mediated neurodegeneration in PD, circumventing the adverse side effects of cyclooxygenase inhibitors

Calcified Cephalohematoma: an unusual case

Introduction: A cephalohematoma is characterized by a collection of serosanguineous fluid localized in the sub periosteum space, being the most common birth injury to the head. It occurs in up to 2.5% of all live births. Rarely a cephalohematoma persists and may calcify. We present a case that illustrates a calcified cephalohematoma that was reabsorbed. Case report: A two-month-old infant presented to the Pediatric Consultation at a first level hospital with a history of persistent right parietal mass, with no other symptoms He was born from instrument-assisted delivery with vacuum and about 72 hours after birth a right parietal tumefaction associated with cutaneous erythema was observed. At the physical examination on the first Pediatric Consultation, he presented with a 3-centimeter-long right parietal mass with hard consistency and no other alterations. Cranial X-rays were requested and showed images compatible with a calcified cephalohematoma, without apparent internal lamina alterations. A wait and see approach was conducted. At twelve-month-old, the mass had been completely reabsorbed and the child’s neurodevelopment was globally adequate. Currently, with four-years-old, the neurodevelopment remains adequate. Discussion and conclusion: Even though cephalohematoma is the most common birth injury to the head, in most cases it is reabsorbed in two to four weeks. Rarely a cephalohematoma persists and may calcify. An adequate medical history and physical examination are very important for a correct diagnosis. Cranium radiography is usually the first line imaging strategy and this patient radiographies were particularly evocative of the diagnosis. In this case a wait and see approach was conducted, the calcified cephalohematoma spontaneously reabsorbed, and the patient showed a good outcome

Reducción del tiempo de tratamiento antimicrobiano en unidades de cuidados intensivos en Fortaleza, Brasil

The authors are grateful for the contribution of the physicians, pharmacists and patients of the Walter Cantídio University Hospital who collaborated in the conduction of this study.Objective: To evaluate the application of the Antimicrobial (ATM) treatment time reduction strategy in Intensive Care Units (ICU) in an Antimicrobial Stewardship Program (ASP). Method: This is a descriptive and cross-sectional study, carried out in two ICU of a university hospital in Fortaleza, Brazil, from January/2017 to January/2019. Adult patients were included, accompanied by a pharmacist, and using ATM, in which the treatment time reduction strategy was applied. The evaluation of the strategy was made through the difference between the predicted time established at the beginning of the treatment and the effective days of use of each ATM. Results: Of the 100 patients included, 51.0 % were male and 64.0 % were elderly. The respiratory system was the most frequently affected by the infections (37.4 %) and the most prevalent classes of ATM were carbapenems (23.0 %) and glycopeptides (20.1 %). There was a decrease from 831 unnecessary days of antimicrobial therapy and from an average of 13.7 to 8.9 days of treatment. The greatest reductions in days were observed for meropenem, with 202 days reduced. The study also allowed the identification of associations between the reduction > 8 days of treatment and the variables length of stay > 22 days and patients in exclusive palliative care, and associations between hospi tal discharge and reductions of up to 7 days of therapy. Conclusions: The data obtained suggest that the presence of an ASP influences the practices of ATM use and its treatment time and emphasize the role of pharmaceutical professionals in these programs.Objetivo: Evaluar la aplicación de la estrategia reducción del tiempo de tratamiento Antimicrobiano (ATM) en Uni dades de Cuidados Intensivos (UCI) en un Programa Stewardship de Antimicrobiano (ASP). Método: Este es un estudio descriptivo y transversal, realizado en dos UCI de un hospital universitario de Fortaleza, Brasil, de enero/2017 a enero/2019. Se incluyeron pacientes adultos, acompañados por un farmacéutico y utilizan do ATM, en los que se aplicó la estrategia de reducción del tiempo de tratamiento. La evaluación de la estrategia se realizó a través de la diferencia entre el tiempo previsto establecido al inicio del tratamiento y los días efectivos de uso de cada ATM. Resultados: De los 100 pacientes incluidos, 51,0 % eran del sexo masculino y 64,0 % ancianos. El sistema respira torio fue el más frecuentemente afectado (37,4 %) y las clases de ATM más prevalentes fueron los carbapenémicos (23,0 %) y los glicopéptidos (20,1 %). Hubo una disminución de 831 días innecesarios de terapia antimicrobiana y de un promedio de 13,7 a 8,9 días de tratamiento. Las mayores reducciones en días se observaron para meropenem, con 202 días reducidos. El estudio también permitió identificar asociaciones entre la reducción > 8 días de trata miento y las variables estancia > 22 días y pacientes en cuidados paliativos exclusivos; y asociaciones entre alta hospitalaria y reducciones de hasta 7 días de terapia. Conclusiones: Los datos obtenidos sugieren que la presencia de un ASP influye en las prácticas de uso de ATM y su tiempo de tratamiento y enfatizan el papel de los profesionales farmacéuticos en estos programa

Reducción del tiempo de tratamiento antimicrobiano en unidades de cuidados intensivos en Fortaleza, Brasil

Objective: To evaluate the application of the Antimicrobial (ATM) treatment time reduction strategy in Intensive Care Units (ICU) in an Antimicrobial Stewardship Program (ASP). Method: This is a descriptive and cross-sectional study, carried out in two ICU of a university hospital in Fortaleza, Brazil, from January/2017 to January/2019. Adult patients were included, accompanied by a pharmacist, and using ATM, in which the treatment time reduction strategy was applied. The evaluation of the strategy was made through the difference between the predicted time established at the beginning of the treatment and the effective days of use of each ATM. Results: Of the 100 patients included, 51.0 % were male and 64.0 % were elderly. The respiratory system was the most frequently affected by the infections (37.4 %) and the most prevalent classes of ATM were carbapenems (23.0 %) and glycopeptides (20.1 %). There was a decrease from 831 unnecessary days of antimicrobial therapy and from an average of 13.7 to 8.9 days of treatment. The greatest reductions in days were observed for meropenem, with 202 days reduced. The study also allowed the identification of associations between the reduction > 8 days of treatment and the variables length of stay > 22 days and patients in exclusive palliative care, and associations between hospital discharge and reductions of up to 7 days of therapy. Conclusions: The data obtained suggest that the presence of an ASP influences the practices of ATM use and its treatment time and emphasize the role of pharmaceutical professionals in these programs.Objetivo: Evaluar la aplicación de la estrategia reducción del tiempo de tratamiento Antimicrobiano (ATM) en Unidades de Cuidados Intensivos (UCI) en un Programa Stewardship de Antimicrobiano (ASP). Método: Este es un estudio descriptivo y transversal, realizado en dos UCI de un hospital universitario de Fortaleza, Brasil, de enero/2017 a enero/2019. Se incluyeron pacientes adultos, acompañados por un farmacéutico y utilizando ATM, en los que se aplicó la estrategia de reducción del tiempo de tratamiento. La evaluación de la estrategia se realizó a través de la diferencia entre el tiempo previsto establecido al inicio del tratamiento y los días efectivos de uso de cada ATM. Resultados: De los 100 pacientes incluidos, 51,0 % eran del sexo masculino y 64,0 % ancianos. El sistema respiratorio fue el más frecuentemente afectado (37,4 %) y las clases de ATM más prevalentes fueron los carbapenémicos (23,0 %) y los glicopéptidos (20,1 %). Hubo una disminución de 831 días innecesarios de terapia antimicrobiana y de un promedio de 13,7 a 8,9 días de tratamiento. Las mayores reducciones en días se observaron para meropenem, con 202 días reducidos. El estudio también permitió identificar asociaciones entre la reducción > 8 días de tratamiento y las variables estancia > 22 días y pacientes en cuidados paliativos exclusivos; y asociaciones entre alta hospitalaria y reducciones de hasta 7 días de terapia. Conclusiones: Los datos obtenidos sugieren que la presencia de un ASP influye en las prácticas de uso de ATM y su tiempo de tratamiento y enfatizan el papel de los profesionales farmacéuticos en estos programas

Chronic voluntary oral methamphetamine induces deficits in spatial learning and hippocampal protein kinase Mzeta with enhanced astrogliosis and cyclooxygenase-2 levels

Methamphetamine (MA) is an addictive drug with neurotoxic effects on the brain producing cognitive impairment and increasing the risk for neurodegenerative disease. Research has focused largely on examining the neurochemical and behavioral deficits induced by injecting relatively high doses of MA [30 mg/kg of body weight (bw)] identifying the upper limits of MA-induced neurotoxicity. Accordingly, we have developed an appetitive mouse model of voluntary oral MA administration (VOMA) based on the consumption of a palatable sweetened oatmeal mash containing a known amount of MA. This VOMA model is useful for determining the lower limits necessary to produce neurotoxicity in the short-term and long-term as it progresses over time. We show that mice consumed on average 1.743 mg/kg bw/hour during 3 hours, and an average of 5.23 mg/kg bw/day over 28 consecutive days on a VOMA schedule. Since this consumption rate is much lower than the neurotoxic doses typically injected, we assessed the effects of longterm chronic VOMA on both spatial memory performance and on the levels of neurotoxicity in the hippocampus. Following 28 days of VOMA, mice exhibited a significant deficit in short-term spatial working memory and spatial reference learning on the radial 8-arm maze (RAM) compared to controls. This was accompanied by a significant decrease in memory markers protein kinase Mzeta (PKMζ), calcium impermeable AMPA receptor subunit GluA2, and the postsynaptic density 95 (PSD-95) protein in the hippocampus. Compared to controls, the VOMA paradigm also induced decreases in hippocampal levels of dopamine transporter (DAT) and tyrosine hydroxylase (TH), as well as increases in dopamine 1 receptor (D1R), glial fibrillary acidic protein (GFAP) and cyclooxygenase-2 (COX-2), with a decrease in prostaglandins E2 (PGE2) and D2 (PGD2). These results demonstrate that chronic VOMA reaching 146 mg/kg bw/28d induces significant hippocampal neurotoxicity. Future studies will evaluate the progression of this neurotoxic state

Mulheres em situação de violência pelo parceiro íntimo: tomada de decisão por apoio institucional especializado

Objetivo: Propõe-se analisar fatores envolvidos na tomada de decisão de mulheres em situação de violência interpessoal, praticada pelo parceiro íntimo, na busca por apoio institucional de referência.Métodos: Pesquisa qualitativa, descritiva e exploratória. Dezesseis mulheres foram entrevistadas, entre junho e setembro de 2012, em um Centro de Referência à Mulher de Duque de Caxias, Rio de Janeiro, Brasil, por meio de instrumento semiestruturado e individual. Os relatos foram analisados pelo método do Discurso do Sujeito Coletivo.Resultados: As mulheres buscaram suporte psicossocial quando a violência interpessoal alcançou o limite da tolerância. Este suporte possibilitou o resgate da autoestima e da confiança, além da tomada de consciência para a necessidade de mudança de vida e de autonomia econômica.Conclusões: As mulheres alcançaram sua autoconfiança com a superação da violência, o que possibilitou o resgate da autoestima e a tomada de decisão para a saída da situação de violência interpessoal praticada pelo parceiro íntimo.Palavras-chave: Enfermagem. Saúde da mulher. Violência contra a mulher. Objetivos de Desenvolvimento do Milênio