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Alzheimer's disease (AD) is the most prevalent form of dementia and is characterized by progressive neurodegeneration leading to severe cognitive, memory, and behavioral impairments. The onset of AD involves a complex interplay among various factors, including age, genetics, chronic inflammation, and impaired energy metabolism. Despite significant efforts, there are currently no effective therapies capable of modifying the course of AD, likely owing to an excessive focus on the amyloid hypothesis and a limited consideration of other intracellular pathways. In the present review, we emphasize the emerging concept of AD as a metabolic disease, where alterations in energy metabolism play a critical role in its development and progression. Notably, glucose metabolism impairment is associated with mitochondrial dysfunction, oxidative stress, Ca2+ dyshomeostasis, and protein misfolding, forming interconnected processes that perpetuate a detrimental self-feeding loop sustaining AD progression. Advanced glycation end products (AGEs), neurotoxic compounds that accumulate in AD, are considered an important consequence of glucose metabolism disruption, and glyceraldehyde (GA), a glycolytic intermediate, is a key contributor to AGEs formation in both neurons and astrocytes. Exploring the impact of GA-induced glucose metabolism impairment opens up exciting possibilities for creating an easy-to-handle in vitro model that recapitulates the early stage of the disease. This model holds great potential for advancing the development of novel therapeutics targeting various intracellular pathways implicated in AD pathogenesis. In conclusion, looking beyond the conventional amyloid hypothesis could lead researchers to discover promising targets for intervention, offering the possibility of addressing the existing medical gaps in AD treatment.
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Doença de Alzheimer , Humanos , Doença de Alzheimer/metabolismo , Gliceraldeído/metabolismo , Estresse Oxidativo , Produtos Finais de Glicação Avançada/metabolismo , Glucose/metabolismo , Peptídeos beta-Amiloides/metabolismoRESUMO
Alzheimer's disease (AD) is a widespread neurodegenerative disorder, affecting a large number of elderly individuals worldwide. Mitochondrial dysfunction, metabolic alterations, and oxidative stress are regarded as cooperating drivers of the progression of AD. In particular, metabolic impairment amplifies the production of reactive oxygen species (ROS), resulting in detrimental alterations to intracellular Ca2+ regulatory processes. The Na+/Ca2+ exchanger (NCX) proteins are key pathophysiological determinants of Ca2+ and Na+ homeostasis, operating at both the plasma membrane and mitochondria levels. Our study aimed to explore the role of NCX1 and NCX3 in retinoic acid (RA) differentiated SH-SY5Y cells treated with glyceraldehyde (GA), to induce impairment of the default glucose metabolism that typically precedes Aß deposition or Tau protein phosphorylation in AD. By using an RNA interference-mediated approach to silence either NCX1 or NCX3 expression, we found that, in GA-treated cells, the knocking-down of NCX3 ameliorated cell viability, increased the intracellular ATP production, and reduced the oxidative damage. Remarkably, NCX3 silencing also prevented the enhancement of Aß and pTau levels and normalized the GA-induced decrease in NCX reverse-mode activity. By contrast, the knocking-down of NCX1 was totally ineffective in preventing GA-induced cytotoxicity except for the increase in ATP synthesis. These findings indicate that NCX3 and NCX1 may differently influence the evolution of AD pathology fostered by glucose metabolic dysfunction, thus providing a potential target for preventing AD.
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Objectives: To describe a case of Shanghai fever disease and to analyze other published reports in non-Asiatic countries, defining clinical characteristics and highlighting that this is not only an Asian disease. Study design: A computerized search without language restriction was conducted using PubMed and Scopus; all references listed were hand-searched to identify any other relevant literature. An article was considered eligible for inclusion in the systematic review if it reported cases with Shanghai fever described in non-Asiatic countries. Our case was also included in the analysis. Results: Ten articles reporting 10 cases of Shanghai fever disease were considered. Fever, diarrhea and ecthyma gangrenosum were the most frequent symptoms observed. Blood was the most common site of isolation for Pseudomonas aeruginosa. Three patients underwent surgery due to necrotizing enteritis and intestinal perforation. Meningitis was documented in one case. None of the patients received antipseudomonal antibiotics within 24 h of admission. The outcome was good in nine cases; only one patient died due to multiple organ failure from Pseudomonas sepsis. No common primary immune deficiency was identified in these patients. Extremely young age (<1 year) was the only host factor predisposing to Shanghai fever. Conclusions: It is important to shed light on this disease in non-Asiatic countries and take into account that it can also affect healthy children. Pediatricians, therefore, should consider Shanghai fever among diagnoses in children with community-onset diarrhea, fever and skin lesions suggestive of ecthyma gangrenosum to start an appropriate treatment sooner and to reduce the mortality in these children.
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Alzheimer's disease (AD) is a neurodegenerative disorder that represents the first cause of dementia. Although there has been significant progress in AD research, the actual mechanisms underlying this pathology remain largely unknown. There is increasing evidence that oxidative stress, metabolic alterations, and mitochondrial dysfunction are key players in the development and worsening of AD. As a result, in the past few years, remarkable attempts have been made to develop neuroprotective strategies against the impairment of mitochondrial dynamics and cell redox status. In the present study, we reveal a novel antioxidant K+ channel-independent effect of the M-current inhibitor XE-991 in SH-SY5Y cells differentiated with retinoic acid (RA) and primary rat cortical neurons exposed to the glycolysis inhibitor glyceraldehyde (GA). This experimental approach aimed to create a condition of hypometabolism accompanied by mitochondrial dysfunction and redox imbalance, as frequently observed in the beginning stage of the disease. We found that XE-991 exerted a neuroprotective action most likely through the resumption of superoxide dismutase (SOD) activity, which was significantly compromised during GA challenge. We also observed that the enhancement of SOD activity was accompanied by a sequence of positive effects; these included the reduction in basal Ca2+ levels within cytoplasmic and mitochondrial compartments, the decrease in mitochondrial reactive oxygen species (ROS) production, the modulation of AMPK/mTOR pathway, the recovery of ΔΨm collapse, the increase in the intracellular ATP content and the decrease in amyloid-ß (Aß) and hyperphosphorylated form of tau protein (pTau) levels. Collectively, our study reveals an off-target antioxidant effect of XE-991 and paves the way toward the further evaluation of new therapeutic uses of already existing molecules to accelerate the process of developing an effective therapy to counteract AD.
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INTRODUCTION AND AIMS: The limited therapeutic options for ischemic stroke treatment render necessary the identification of new strategies. In recent years, it has been shown that natural compounds may represent a valid therapeutic opportunity. Therefore, the present study aimed to evaluate the protective effect of Ruta graveolens water extract (RGWE) in an in vivo experimental model of brain ischemia. METHODS: RGWE effects on ischemic damage and neurological function were evaluated in adult rats subjected to transient occlusion of the Middle Cerebral Artery (tMCAO), receiving two intraperitoneal injections of RGWE, 100 and 300 min after the induction of ischemia. In addition, astroglial and microglial activation was measured as GFAP and IBA-1 expression by immunofluorescence and confocal microscopy analysis. RESULTS: Treatment with RGWE containing 10 mg/kg of Rutin, the major component, ameliorates the ischemic damage and improves neurological performances. Interestingly, the pro-inflammatory states of astrocytes and microglia, respectively detected by using C3 and iNOS markers, were significantly reduced in ipsilateral cortical and striatal areas in ischemic RGWE-treated rats. CONCLUSIONS: RGWE shows a neuroprotective effect on brain infarct volume extent in a transient focal cerebral ischemia model and this effect was paralleled by the prevention of pro-inflammatory astroglial and microglial activation. Collectively, our findings support the idea that natural compounds may represent potential therapeutic opportunities against ischemic stroke.
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Isquemia Encefálica , Ataque Isquêmico Transitório , AVC Isquêmico , Fármacos Neuroprotetores , Ruta , Animais , Encéfalo , Isquemia Encefálica/tratamento farmacológico , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/tratamento farmacológico , Isquemia , Ataque Isquêmico Transitório/complicações , Ataque Isquêmico Transitório/tratamento farmacológico , Ataque Isquêmico Transitório/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Ratos , ÁguaRESUMO
BACKGROUND: Congenital maxillomandibular syngnathia is a rare craniofacial anomaly leading to difficulties in feeding, breathing and ability to thrive. The fusion may consist of soft tissue union (synechiae) to hard tissue union. Isolated cases of maxillomandibular fusion are extremely rare, it is most often syndromic in etiology. CASE PRESENTATION: Clinical management of a female newborn with oromaxillofacial abnormities (synechiae, cleft palate, craniofacial dysmorphisms, dental anomaly) and extraoral malformations (skinfold overlying the nails of both halluces, syndactyly, abnormal external genitalia) is presented. The associated malformations addressed to molecular genetic investigations revealing an interferon regulatory factor 6 (IRF6)-related disorder (van der Woude syndrome/popliteal pterygium syndrome). A novel de novo heterozygous mutation in exon 4 of IRF6 gene on chromosome 1q32.2, precisely c.262A > G (p.Asn88Asp), was found. Similarities are discussed with known asparagine missense mutations in the same codon, which may alter IRF6 gene function by reduced DNA-binding ability. A concomitant maternal Xp11.22 duplication involving two microRNA genes could contribute to possible epigenetic effects. CONCLUSIONS: Our reported case carrying a novel mutation can contribute to expand understandings of molecular mechanisms underlying synechiae and orofacial clefting and to correct diagnosing of incomplete or overlapping features in IRF6-related disorders. Additional multidisciplinary evaluations to establish the phenotypical extent of the IRF6-related disorder and to address family counseling should not only be focused on the surgical corrections of syngnathia and cleft palate, but also involve comprehensive otolaryngologic, audiologic, logopedic, dental, orthopedic, urological and psychological evaluations.
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Fenda Labial , Fissura Palatina , Deformidades Congênitas das Extremidades Inferiores , Fenda Labial/genética , Fissura Palatina/diagnóstico , Fissura Palatina/genética , Fissura Palatina/cirurgia , Feminino , Humanos , Recém-Nascido , Fatores Reguladores de Interferon/química , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Deformidades Congênitas das Extremidades Inferiores/genética , Mutação , Mutação de Sentido IncorretoRESUMO
Reactive oxygen species (ROS) are versatile molecules that, even if produced in the background of many biological processes and responses, possess pleiotropic roles categorized in two interactive yet opposite domains. In particular, ROS can either function as signaling molecules that shape physiological cell functions, or act as deleterious end products of unbalanced redox reactions. Indeed, cellular redox status needs to be tightly regulated to ensure proper cellular functioning, and either excessive ROS accumulation or the dysfunction of antioxidant systems can perturb the redox homeostasis, leading to supraphysiological concentrations of ROS and potentially harmful outcomes. Therefore, whether ROS would act as signaling molecules or as detrimental factors strictly relies on a dynamic equilibrium between free radical production and scavenging resources. Of notice, the mammalian brain is particularly vulnerable to ROS-mediated toxicity, because it possesses relatively poor antioxidant defenses to cope with the redox burden imposed by the elevated oxygen consumption rate and metabolic activity. Many features of neurodegenerative diseases can in fact be traced back to causes of oxidative stress, which may influence both the onset and progression of brain demise. This review focuses on the description of the dual roles of ROS as double-edge sword in both physiological and pathological settings, with reference to Alzheimer's and Parkinson's diseases.
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Spatial and temporal control of calcium (Ca2+) levels is essential for the background rhythms and responses of living cells to environmental stimuli. Whatever other regulators a given cellular activity may have, localized and wider scale Ca2+ events (sparks, transients, and waves) are hierarchical determinants of fundamental processes such as cell contraction, excitability, growth, metabolism and survival. Different cell types express specific channels, pumps and exchangers to efficiently generate and adapt Ca2+ patterns to cell requirements. The Na+/Ca2+ exchangers (NCXs) in particular contribute to Ca2+ homeostasis by buffering intracellular Ca2+ loads according to the electrochemical gradients of substrate ions - i.e., Ca2+ and sodium (Na+) - and under a dynamic control of redundant regulatory processes. An interesting feature of NCX emerges from the strict relationship that connects transporter activity with cell metabolism: on the one hand NCX operates under constant control of ATP-dependent regulatory processes, on the other hand the ion fluxes generated through NCX provide mechanistic support for the Na+-driven uptake of glutamate and Ca2+ influx to fuel mitochondrial respiration. Proof of concept evidence highlights therapeutic potential of preserving a timed and balanced NCX activity in a growing rate of diseases (including excitability, neurodegenerative, and proliferative disorders) because of an improved ability of stressed cells to safely maintain ion gradients and mitochondrial bioenergetics. Here, we will summarize and review recent works that have focused on the pathophysiological roles of NCXs in balancing the two-way relationship between Ca2+ signals and metabolism.
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Cálcio , Trocador de Sódio e Cálcio , Transporte Biológico , Cálcio/metabolismo , Homeostase/fisiologia , Sódio/metabolismo , Trocador de Sódio e Cálcio/metabolismoRESUMO
INTRODUCTION: The second most common form of early-onset dementia-frontotemporal dementia (FTD)-is often characterized by the aggregation of the microtubule-associated protein tau. Here we studied the mechanism of tau-induced neuronal dysfunction in neurons with the FTD-related 10+16 MAPT mutation. METHODS: Live imaging, electrophysiology, and redox proteomics were used in 10+16 induced pluripotent stem cell-derived neurons and a model of tau spreading in primary cultures. RESULTS: Overproduction of mitochondrial reactive oxygen species (ROS) in 10+16 neurons alters the trafficking of specific glutamate receptor subunits via redox regulation. Increased surface expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors containing GluA1 and NR2B subunits leads to impaired glutamatergic signaling, calcium overload, and excitotoxicity. Mitochondrial antioxidants restore the altered response and prevent neuronal death. Importantly, extracellular 4R tau induces the same pathological response in healthy neurons, thus proposing a mechanism for disease propagation. DISCUSSION: These results demonstrate mitochondrial ROS modulate glutamatergic signaling in FTD, and suggest a new therapeutic strategy.
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Demência Frontotemporal , Células-Tronco Pluripotentes Induzidas , Demência Frontotemporal/genética , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Mitocôndrias , Neurônios/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Proteínas tau/metabolismoRESUMO
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive regression and memory loss. Dysfunctions of both glucose metabolism and mitochondrial dynamics have been recognized as the main upstream events of the degenerative processes leading to AD. It has been recently found that correcting cell metabolism by providing alternative substrates can prevent neuronal injury by retaining mitochondrial function and reducing AD marker levels. Here, we induced an AD-like phenotype by using the glycolysis inhibitor glyceraldehyde (GA) and explored whether L-carnitine (4-N-trimethylamino-3-hydroxybutyric acid, LC) could mitigate neuronal damage, both in SH-SY5Y neuroblastoma cells and in rat primary cortical neurons. We have already reported that GA significantly modified AD marker levels; here we demonstrated that GA dramatically compromised cellular bioenergetic status, as revealed by glycolysis and oxygen consumption rate (OCR) evaluation. We found that LC ameliorated cell survival, improved OCR and ATP synthesis, prevented the loss of the mitochondrial membrane potential (Δψm) and reduced the formation of reactive oxygen species (ROS). Of note, the beneficial effect of LC did not rely on the glycolytic pathway rescue. Finally, we noticed that LC significantly reduced the increase in pTau levels induced by GA. Overall, these findings suggest that the use of LC can promote cell survival in the setting of the metabolic impairments commonly observed in AD. Our data suggest that LC may act by maintaining mitochondrial function and by reducing the pTau level.
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Doença de Alzheimer/metabolismo , Carnitina/farmacologia , Gliceraldeído/toxicidade , Fármacos Neuroprotetores/farmacologia , Trifosfato de Adenosina/biossíntese , Doença de Alzheimer/induzido quimicamente , Animais , Sobrevivência Celular/efeitos dos fármacos , Glicólise , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Modelos Biológicos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Proteínas tau/metabolismoRESUMO
The novel coronavirus disease 2019 (COVID-19) is a global pandemic that continues to sweep across the world, posing an urgent need for effective therapies and prevention of the spread of the severe acute respiratory syndrome related to coronavirus-2 (SARS-CoV-2). A major hypothesis that is currently guiding research and clinical care posits that an excessive and uncontrolled surge of pro-inflammatory cytokines (the so-called "cytokine storm") drives morbidity and mortality in the most severe cases. In the overall efforts made to develop effective and safe therapies (including vaccines) for COVID-19, clinicians are thus repurposing ready-to-use drugs with direct or indirect anti-inflammatory and immunomodulatory activities. Speculatively, there are many opportunities and challenges in targeting immune/inflammatory processes in the evolving settings of COVID-19 disease because of the need to safely balance the fight against virus and aggressive inflammation versus the suppression of host immune defenses and the risk of additional harms in already compromised patients. To this end, many studies are globally underway to weigh the pros and cons of tailoring drugs used for inflammatory-driven conditions to COVID-19 patient care, and the next step will be to summarize the growing clinical trial experience into clean clinical practice. Based on the current evidence, anti-inflammatory drugs should be considered as complementary approaches to anti-viral drugs that need to be timely introduced in the management of COVID-19 according to disease severity. While drugs that target SARS-CoV-2 entry or replication are expected to confer the greatest benefits at the early stage of the infection, anti-inflammatory drugs would be more effective in limiting the inflammatory processes that drive the worsening of the disease.
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Remote limb ischemic postconditioning (RLIP) is a well-established neuroprotective strategy able to protect the brain from a previous harmful ischemic insult through a sub-lethal occlusion of the femoral artery. Neural and humoral mechanisms have been proposed as mediators required to transmit the peripheral signal from limb to brain. Moreover, different studies suggest that protection observed at brain level is associated to a general genetic reprogramming involving also microRNAs (miRNAs) intervention. Methods: Brain ischemia was induced in male rats by transient occlusion of the middle cerebral artery (tMCAO), whereas RLIP was achieved by one cycle of temporary occlusion of the ipsilateral femoral artery after tMCAO. The expression profile of 810 miRNAs was evaluated in ischemic brain samples from rats subjected either to tMCAO or to RLIP. Among all analyzed miRNAs, there were four whose expression were upregulated after stroke and returned to basal level after RLIP, thus suggesting a possible involvement in RLIP-induced neuroprotection. These selected miRNAs were intracerebroventricularly infused in rats subjected to remote ischemic postconditioning, and their effect was evaluated in terms of brain damage, neurological deficit scores and expression of putative targets. Results: Twenty-one miRNAs, whose expression was significantly affected by tMCAO and by tMCAO plus RLIP, were selected based on microarray microfluidic profiling. Our data showed that: (1) stroke induced an up-regulation of let-7a and miR-143 (2) these two miRNAs were involved in the protective effects induced by RLIP and (3) HIF1-α contributes to their protective effect. Indeed, their expression was reduced after RLIP and the exogenous intracerebroventricularly infusion of let-7a and miR-143 mimics prevented neuroprotection and HIF1-α overexpression induced by RLIP. Conclusions: Prevention of cerebral let-7a and miR-143 overexpression induced by brain ischemia emerges as new potential strategy in stroke intervention.
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Pós-Condicionamento Isquêmico/métodos , AVC Isquêmico/reabilitação , MicroRNAs/metabolismo , Reabilitação do Acidente Vascular Cerebral/métodos , Animais , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Infusões Intraventriculares , AVC Isquêmico/genética , AVC Isquêmico/patologia , Masculino , MicroRNAs/agonistas , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Técnicas Estereotáxicas , Regulação para CimaRESUMO
BACKGROUND: High resolution manometry (HRM), has been recently introduced in clinical practice to detect esophageal intraluminal pressure and esophageal motor function. We evaluated the feasibility and usefulness of intraoperative esophageal HRM during antireflux laparoscopic procedures in pediatric cases with neurological impairment (NI) or esophageal atresia (EA). METHODS: From January to November 2019, seven children (5 NI, 2 EA) with gastroesophageal reflux (GER) were enrolled. Data on intraoperative pressure changes of the esophagogastric junction (EGJ) and postoperative follow-up data were collected. RESULTS: Average preoperative LES pressures were not significantly different from postoperative pressures. A sliding hernia was detected in all patients as evidenced by EGJ double peak pressures. Hernia correction after esophageal traction was complete in 71.4% of the patients, and residual hernia (<2 cm) was detected in 28.6%. Postoperative EGJ pressures were higher compared to preoperative sphincteric pressures (p < 0.001); in NI patients, higher postoperative values were noted compared to EA (p = 0.05). No sliding hernia and/or GER relapses were recorded. Two patients reported dysphagia postoperatively. CONCLUSIONS: Intraoperative HRM may optimize esophageal pressure changes during laparoscopic fundoplication. Further studies are needed to confirm the usefulness of a tailored surgical approach to reduce postoperative complications.
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Recent developments in endovascular radiological techniques and devices have rendered embolization a major therapeutic option prior to surgery in many renal vascular or neoplastic diseases. A 19-yearold female patient, with a diagnosis of tuberous sclerosis complex (TSC) in childhood, was admitted with severe anemia. Polycystic kidney disease in end-stage renal failure appeared four years before and the patient has been undergoing peritoneal dialysis. The patient's medical history also included bilateral renal angiomyolipomas (AMLs). One year earlier, a unilateral endovascular embolization was performed to repair a bleeding aneurysm at the right renal upper pole. A second bilateral ruptured renal aneurysm was diagnosed at admission. To continue with peritoneal dialysis and prevent intrarenal hemorrhage and intraperitonal bleeding, an urgent bilateral renal AE was performed. Two months later she underwent a bilateral retroperitoneal nephrectomy. The posterior surgical approach, preserved the peritoneal surface area and adequate conditions to continue dialysis. At histology, bilateral AMLs were confirmed and a renal cell carcinoma of the right kidney was concurrently discovered. She undergoes continuous peritoneal dialysis. Urgent selective renal AE represents a feasible treatment for bilateral AML bleeding. It is safe and feasible before performing nephrectomy in patients with end-stage renal failure.
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Increasing evidence suggests that metabolic alterations may be etiologically linked to neurodegenerative disorders such as Parkinson's disease (PD) and in particular empathizes the possibility of targeting mitochondrial dysfunctions to improve PD progression. Under different pathological conditions (i.e., cardiac and neuronal ischemia/reperfusion injury), we showed that supplementation of energetic substrates like glutamate exerts a protective role by preserving mitochondrial functions and enhancing ATP synthesis through a mechanism involving the Na+-dependent excitatory amino acid transporters (EAATs) and the Na+/Ca2+ exchanger (NCX). In this study, we investigated whether a similar approach aimed at promoting glutamate metabolism would be also beneficial against cell damage in an in vitro PD-like model. In retinoic acid (RA)-differentiated SH-SY5Y cells challenged with α-synuclein (α-syn) plus rotenone (Rot), glutamate significantly improved cell viability by increasing ATP levels, reducing oxidative damage and cytosolic and mitochondrial Ca2+ overload. Glutamate benefits were strikingly lost when either EAAT3 or NCX1 expression was knocked down by RNA silencing. Overall, our results open the possibility of targeting EAAT3/NCX1 functions to limit PD pathology by simultaneously favoring glutamate uptake and metabolic use in dopaminergic neurons.
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Transportador 3 de Aminoácido Excitatório/metabolismo , Ácido Glutâmico/metabolismo , Doença de Parkinson/genética , Trocador de Sódio e Cálcio/metabolismo , Linhagem Celular Tumoral , Humanos , Neuroproteção , Doença de Parkinson/metabolismo , TransfecçãoRESUMO
Increasing evidence suggests that metabolic dysfunctions are at the roots of neurodegenerative disorders such as Alzheimer's disease (AD). In particular, defects in cerebral glucose metabolism, which have been often noted even before the occurrence of clinical symptoms and histopathological lesions, are now regarded as critical contributors to the pathogenesis of AD. Hence, the stimulation of energy metabolism, by enhancing the availability of specific metabolites, might be an alternative way to improve ATP synthesis and to positively affect AD progression. For instance, glutamate may serve as an intermediary metabolite for ATP synthesis through the tricarboxylic acid (TCA) cycle and the oxidative phosphorylation. We have recently shown that two transporters are critical for the anaplerotic use of glutamate: the Na+-dependent Excitatory Amino Acids Carrier 1 (EAAC1) and the Na+-Ca2+ exchanger 1 (NCX1). Therefore, in the present study, we established an AD-like phenotype by perturbing glucose metabolism in both primary rat cortical neurons and retinoic acid (RA)-differentiated SH-SY5Y cells, and we explored the potential of glutamate to halt cell damage by monitoring neurotoxicity, AD markers, ATP synthesis, cytosolic Ca2+ levels and EAAC1/NCX1 functional activities. We found that glutamate significantly increased ATP production and cell survival, reduced the increase of AD biomarkers (amyloid ß protein and the hyperphosphorylated form of tau protein), and recovered the increase of NCX reverse-mode activity. The RNA silencing of either EAAC1 or NCX1 caused the loss of the beneficial effects of glutamate, suggesting the requirement of a functional interplay between these transporters for glutamate-induced protection. Remarkably, our results indicate, as proof-of-principle, that facilitating the use of alternative fuels, like glutamate, may be an effective approach to overcome deficits in glucose utilization and significantly slow down neuronal degenerative process in AD.
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Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Transportador 3 de Aminoácido Excitatório/metabolismo , Ácido Glutâmico/metabolismo , Substâncias Protetoras/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Morte Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Córtex Cerebral/patologia , Gliceraldeído , Humanos , Modelos Biológicos , Neurônios/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Tretinoína/farmacologiaRESUMO
Background: Laparoscopic cholecystectomy (LC) is the standard of care for gallbladder (GB) pathologies. We evaluated clinical, ultrasonographic (US) data as well as histopathological findings in children affected with symptomatic cholecystic disease (SCD) who underwent LC, with the aim of defining surgical timing. Methods: We reviewed our cases who underwent elective LC (ELC) or urgent LC (ULC). Clinical, US, surgical and histological features were used to create different risk scores. Results: We considered 26 children (17 ELC/9 ULC). US signs were not different in the two groups (p > 0.05). Operating times were longer in ELC than in ULC (p = 0.01). Histopathological evaluation revealed fibrosis and atrophy in both ELC and ULC. The clinical risk score was higher in ELC compared to ULC (p < 0.001). An increased operative risk score was noted in patients with systemic inflammatory signs (OR1.98), lithotherapy (OR1.4.3) and wall thickening ≥3 mm (OR2.6). An increased histopathological risk score was detected in children with symptom duration >7 days (OR3.61), concomitant hematological disease (OR1.23) and lithotherapy (OR3.61). Conclusion: Criteria adopted in adults cannot be adopted to detect the severity of GB damage in children. A dedicated clinical and US score is mandatory to define the most appropriate surgical timing.
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Cell membranes spatially define gradients that drive the complexity of biological signals. To guarantee movements and exchanges of solutes between compartments, membrane transporters negotiate the passages of ions and other important molecules through lipid bilayers. The Na+/Ca2+ exchangers (NCXs) in particular play central roles in balancing Na+ and Ca2+ fluxes across diverse proteolipid borders in all eukaryotic cells, influencing cellular functions and fate by multiple means. To prevent progression from balance to disease, redundant regulatory mechanisms cooperate at multiple levels (transcriptional, translational, and post-translational) and guarantee that the activities of NCXs are finely-tuned to cell homeostatic requirements. When this regulatory network is disturbed by pathological forces, cells may approach the end of life. In this review, we will discuss the main findings, controversies and open questions about regulatory mechanisms that control NCX functions in health and disease.
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Ativação do Canal Iônico , Trocador de Sódio e Cálcio/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Humanos , Modelos BiológicosRESUMO
It is well established that mitochondria are the main source of ATP production within cells. However, mitochondria have other remarkable functions, serving as important modulators of cellular Ca2+ signaling, and it is now generally recognized that control over Ca2+ homeostasis is intrinsically interwoven with mitochondrial abilities to adjust and tune ATP production. In this review, we describe the mechanisms that mitochondria use to balance Ca2+ homeostasis maintenance and cell energy metabolism. In recent years, the knowledge on the molecular machinery mediating Ca2+ influx/efflux has been improved and, albeit still open to further investigations, several lines of evidence converge on the hypothesis that plasma membrane Na+/Ca2+ exchanger (NCX) isoforms are also expressed at the mitochondrial level, where they contribute to the Ca2+ and Na+ homeostasis maintenance. In particular, the connection between mitochondrial NCX activity and metabolic substrates utilization is further discussed here. We also briefly focus on the alterations of both mitochondrial Ca2+ handling and cellular bioenergetics in neurodegenerative diseases, such as Parkinson's and Alzheimer's disease.
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Cálcio/metabolismo , Metabolismo Energético , Homeostase , Mitocôndrias/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Animais , Sinalização do Cálcio , HumanosRESUMO
Energy metabolism impairment is a central event in the pathophysiology of ischemia. The limited availability of glucose and oxygen strongly affects mitochondrial activity, thus leading to ATP depletion. In this setting, the switch to alternative energy sources could ameliorate cells survival by enhancing ATP production, thus representing an attractive strategy for ischemic treatment. In this regard, some studies have recently re-evaluated the metabolic role of glutamate and its potential to promote cell survival under pathological conditions. In the present review, we discuss the ability of glutamate to exert an "energizing role" in cardiac and neuronal models of hypoxia/reoxygenation (H/R) injury, focusing on the Na+/Ca2+ exchanger (NCX) and the Na+-dependent excitatory amino acid transporters (EAATs) as key players in this metabolic pathway.