RESUMO
The disruption of mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) plays a relevant role in Alzheimer's disease (AD). MAMs have been implicated in neuronal dysfunction and death since it is associated with impairment of functions regulated in this subcellular domain, including lipid synthesis and trafficking, mitochondria dysfunction, ER stress-induced unfolded protein response (UPR), apoptosis, and inflammation. Since MAMs play an important role in lipid metabolism, in this study we characterized and investigated the lipidome alterations at MAMs in comparison with other subcellular fractions, namely microsomes and mitochondria, using an in vitro model of AD, namely the mouse neuroblastoma cell line (N2A) over-expressing the APP familial Swedish mutation (APPswe) and the respective control (WT) cells. Phospholipids (PLs) and fatty acids (FAs) were isolated from the different subcellular fractions and analyzed by HILIC-LC-MS/MS and GC-MS, respectively. In this in vitro AD model, we observed a down-regulation in relative abundance of some phosphatidylcholine (PC), lysophosphatidylcholine (LPC), and lysophosphatidylethanolamine (LPE) species with PUFA and few PC with saturated and long-chain FA. We also found an up-regulation of CL, and antioxidant alkyl acyl PL. Moreover, multivariate analysis indicated that each organelle has a specific lipid profile adaptation in N2A APPswe cells. In the FAs profile, we found an up-regulation of C16:0 in all subcellular fractions, a decrease of C18:0 levels in total fraction (TF) and microsomes fraction, and a down-regulation of 9-C18:1 was also found in mitochondria fraction in the AD model. Together, these results suggest that the over-expression of the familial APP Swedish mutation affects lipid homeostasis in MAMs and other subcellular fractions and supports the important role of lipids in AD physiopathology.
Assuntos
Doença de Alzheimer , Lipidômica , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Animais , Camundongos , Lipidômica/métodos , Linhagem Celular Tumoral , Membranas Mitocondriais/metabolismo , Mitocôndrias/metabolismo , Fosfolipídeos/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Humanos , Metabolismo dos Lipídeos/fisiologia , Membranas Associadas à MitocôndriaRESUMO
After spinal cord injury (SCI), infiltrating macrophages undergo excessive phagocytosis of myelin and cellular debris, forming lipid-laden foamy macrophages. To understand their role in the cellular pathology of SCI, investigation of the foamy macrophage phenotype in vitro revealed a pro-inflammatory profile, increased reactive oxygen species (ROS) production, and mitochondrial dysfunction. Bioinformatic analysis identified PI3K as a regulator of inflammation in foamy macrophages, and inhibition of this pathway decreased their lipid content, inflammatory cytokines, and ROS production. Macrophage-specific inhibition of PI3K using liposomes significantly decreased foamy macrophages at the injury site after a mid-thoracic contusive SCI in mice. RNA sequencing and in vitro analysis of foamy macrophages revealed increased autophagy and decreased phagocytosis after PI3K inhibition as potential mechanisms for reduced lipid accumulation. Together, our data suggest that the formation of pro-inflammatory foamy macrophages after SCI is due to the activation of PI3K signaling, which increases phagocytosis and decreases autophagy.
Assuntos
Fosfatidilinositol 3-Quinases , Traumatismos da Medula Espinal , Camundongos , Animais , Fosfatidilinositol 3-Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Macrófagos/metabolismo , Traumatismos da Medula Espinal/metabolismo , Lipídeos , Medula Espinal/patologiaRESUMO
Glyphosate (GLY), the most widely used herbicide, has been regarded as an emergent environmental contaminant due to its constant and cumulative use, with potential harm to non-target organisms, such as crops, disrupting cells' redox balance. Therefore, plants need to fine-tune their antioxidant (AOX) mechanisms to thrive under GLY-contaminated environments. Proline overaccumulation is a common response in plants exposed to GLY, yet its role in GLY-induced toxicity remains unclear. Thus, this study explores whether Pro overaccumulation in response to GLY is perceived as a downstream tolerance mechanism or an early-warning stress signal. To investigate this, Arabidopsis thaliana T-DNA mutant lines for Pro biosynthetic (P5CS1) and catabolic genes (ProDH) were used and screened for their GLY susceptibility. Upon seedlings' exposure to GLY (0.75 mg L-1) for 14 days, the herbicide led to reduced biomass in all genotypes, accompanied by Pro overaccumulation. Mutants with heightened Pro levels (prodh) exhibited the greatest biomass reduction, increased lipid peroxidation (LP), and hydrogen peroxide (H2O2) levels, accompanied by a compromised performance of the AOX system. Conversely, p5cs1-4, mutants with lower Pro levels, demonstrated an enhanced AOX system activation, not only with increased levels of glutathione (GSH) and ascorbate (AsA), but also with increased activity of both ascorbate peroxidase (APX) and catalase (CAT). These findings suggest that Pro overaccumulation under GLY exposure is associated with stress sensitivity rather than tolerance, highlighting its potential as an early-warning signal for GLY toxicity in non-target plants and for detecting weed resistance.
Assuntos
Arabidopsis , Glicina , Glifosato , Herbicidas , Prolina , Glicina/análogos & derivados , Glicina/farmacologia , Glicina/toxicidade , Prolina/metabolismo , Arabidopsis/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Herbicidas/toxicidade , Herbicidas/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Antioxidantes/metabolismo , Peróxido de Hidrogênio/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/fisiologia , Plântula/metabolismoRESUMO
Glioblastoma (GBM) is the most common and fatal primary tumor of the central nervous system (CNS) and current treatments have limited success. Chemokine signaling regulates both malignant cells and stromal cells of the tumor microenvironment (TME), constituting a potential therapeutic target against brain cancers. Here, we investigated the C-C chemokine receptor type 7 (CCR7) and the chemokine (C-C-motif) ligand 21 (CCL21) for their expression and function in human GBM and then assessed their therapeutic potential in preclinical mouse GBM models. In GBM patients, CCR7 expression positively associated with a poor survival. CCL21-CCR7 signaling was shown to regulate tumor cell migration and proliferation while also controlling tumor associated microglia/macrophage recruitment and VEGF-A production, thereby controlling vascular dysmorphia. Inhibition of CCL21-CCR7 signaling led to an increased sensitivity to temozolomide-induced tumor cell death. Collectively, our data indicate that drug targeting of CCL21-CCR7 signaling in tumor and TME cells is a therapeutic option against GBM.
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Glioblastoma , Microglia , Animais , Camundongos , Humanos , Glioblastoma/tratamento farmacológico , Receptores CCR7/genética , Macrófagos , Sistema Nervoso Central , Microambiente Tumoral , Quimiocina CCL21RESUMO
Macroalgae are known as abundant sources of phytochemicals, which offer a plethora of beneficial biological properties. Besides being the most notable classes of compounds found in macroalgae, phlorotannins, bromophenols, and terpenoids comprise some of the most relevant for their biological properties. Phlorotannins, mainly prevalent in brown algae and structurally characterized as complex polyphenolic compounds derived from phloroglucinol units, possess robust antioxidant, anti-inflammatory, antitumor, and cytotoxic activities, modulated by factors such as the degree of polymerization and environmental conditions. Bromophenols, halogenated compounds found in algae and other marine organisms, exhibit significant antioxidant and antiviral properties. Their diverse structures and bromination patterns contribute to their potential as therapeutic and chemical defense agents. Pigments (chemically described as primary terpenoids) play a critical role in light absorption and energy transfer in macroalgae and are divided into three main groups: (i) carotenoids, which are primarily found in brown algae and provide photoprotective and antioxidant benefits; (ii) chlorophylls, known for facilitating the conversion of light into biological energy; and (iii) phycobilins, which are mostly found in red algae and play important roles in light absorption and energy transfer, besides providing remarkable health benefits. Finally, secondary terpenoids, which are particularly abundant in red algae (e.g., the Rhodomelaceae family) are central to cellular interactions and exhibit significant antioxidant, antimicrobial, antidiabetic, and anti-inflammatory properties. This study represents a detailed analysis of the biosynthesis, structural diversity, and biological activities of these macroalgae metabolites, emphasizing their potential biological properties.
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Alga Marinha , Alga Marinha/metabolismo , Alga Marinha/química , Humanos , Antioxidantes/farmacologia , Animais , Phaeophyceae/metabolismo , Phaeophyceae/química , Terpenos/farmacologia , Terpenos/metabolismo , Terpenos/química , Anti-Inflamatórios/farmacologia , Taninos/farmacologia , Organismos AquáticosRESUMO
The management of acute pain focuses on a multimodal approach integrating both pharmacological and non-pharmacological treatments. In recent years, caution towards opioids has increased, with several studies showing that they are not necessarily more effective than non opioid analgesics for pain relief for musculoskeletal pain, which is the most common painful symptom in outpatient settings, and have the disadvantages of more side effects and a risk of dependence. Adjuvant and non-pharmacological treatments (e.g. manual medicine, acupuncture, hypnosis) are gaining importance to reduce therapeutic escalation and improve pain management. This approach which can be more personalized, aims to minimize risks while ensuring effective relief of acute pain.
La prise en charge de la douleur aiguë se centre autour d'une approche multimodale intégrant des traitements pharmacologiques et non pharmacologiques. Ces dernières années, la prudence envers les opiacés s'est accrue, plusieurs études montrant qu'ils ne sont pas forcément plus efficaces que les non-opiacés face à la douleur musculosquelettique notamment, qui est le symptôme douloureux le plus fréquent en ambulatoire, et ont l'inconvénient d'apporter davantage d'effets indésirables et un risque de dépendance. Les traitements adjuvants et non pharmacologiques (comme la médecine manuelle, l'acupuncture, l'hypnose) gagnent en importance pour réduire l'escalade thérapeutique et améliorer la gestion de la douleur. Cette approche personnalisée vise à minimiser les risques tout en assurant un soulagement efficace de la douleur aiguë.
Assuntos
Dor Aguda , Assistência Ambulatorial , Manejo da Dor , Humanos , Dor Aguda/terapia , Manejo da Dor/métodos , Assistência Ambulatorial/métodos , Pacientes AmbulatoriaisRESUMO
Heteroplasmy refers to the coexistence of more than one variant of the mitochondrial genome (mtDNA). Mutated or partially deleted mtDNAs can induce chronic metabolic impairment and cause mitochondrial diseases when their heteroplasmy levels exceed a critical threshold. These mutant mtDNAs can be maternally inherited or can arise de novo. Compelling evidence has emerged showing that mutant mtDNA levels can vary and change in a nonrandom fashion across generations and amongst tissues of an individual. However, our lack of understanding of the basic cellular and molecular mechanisms of mtDNA heteroplasmy dynamics has made it difficult to predict who will inherit or develop mtDNA-associated diseases. More recently, with the advances in technology and the establishment of tractable model systems, insights into the mechanisms underlying the selection forces that modulate heteroplasmy dynamics are beginning to emerge. In this review, we summarize evidence from different organisms, showing that mutant mtDNA can experience both positive and negative selection. We also review the recently identified mechanisms that modulate heteroplasmy dynamics. Taken together, this is an opportune time to survey the literature and to identify key cellular pathways that can be targeted to develop therapies for diseases caused by heteroplasmic mtDNA mutations.
Assuntos
DNA Mitocondrial , Heteroplasmia , DNA Mitocondrial/genética , Mitocôndrias/genéticaRESUMO
BACKGROUND: In Brazil, the COVID-19 pandemic found the universal and public Unified Health System (SUS) with problems accumulated over time, due, among other reasons, to low investments, and disparities in resource distribution. The preparedness and response of the healthcare system, involving the SUS and a private sector, was affected by large socioeconomic and healthcare access inequities. This work was aimed at offering an overview of COVID-19 inpatient mortality during the pandemic in Brazil, exploring factors associated with its variations and, specifically, differences across public, private (for-profit) and philanthropic (private non-profit) inpatient healthcare units, providers, and non-providers of services to the SUS. METHODS: This cross-sectional study used public secondary data. The main data source was the SIVEP-Gripe, which comprises data on severe acute respiratory illness records prospectively collected. We also employed the National Record of Health Establishments, the SUS' Hospitalization Information System and municipalities' data from IBGE. We considered adult COVID-19 hospitalizations registered in SIVEP-Gripe from February 2020 to December 2022 in inpatient healthcare units with a minimum of 100 cases in the period. Data analyses explored the occurrence of inpatient mortality, employing general linear mixed models to identify the effects of patients', health care processes', healthcare units' and municipalities' characteristics on it. RESULTS: About 70% of the COVID-19 hospitalizations in Brazil were covered by the SUS, which attended the more vulnerable population groups and had worse inpatient mortality. In general, non-SUS private and philanthropic hospitals, mostly reimbursed by healthcare insurance plans accessible for more privileged socioeconomic classes, presented the best outcomes. Southern Brazil had the best performance among the macro-regions. Black and indigenous individuals, residents of lower HDI municipalities, and those hospitalized out of their residence city presented higher odds of inpatient mortality. Moreover, adjusted inpatient mortality rates were higher in the pandemic peak moments and were significantly reduced after COVID-19 vaccination reaching a reasonable coverage, from July 2021. CONCLUSIONS: COVID-19 exposed socioeconomic and healthcare inequalities and the importance and weaknesses of SUS in Brazil. This work indicates the need to revert the disinvestment in the universal public system, a fundamental policy for reduction of inequities in the country.
Assuntos
COVID-19 , Adulto , Humanos , COVID-19/epidemiologia , Estudos Transversais , Brasil/epidemiologia , Pacientes Internados , Pandemias , Vacinas contra COVID-19 , Acessibilidade aos Serviços de SaúdeRESUMO
Endoplasmic reticulum (ER) stress and mitochondrial dysfunction, which are key events in the initiation and/or progression of several diseases, are correlated with alterations at ER-mitochondria contact sites, the so-called "Mitochondria-Associated Membranes" (MAMs). These intracellular structures are also implicated in NLRP3 inflammasome activation which is an important driver of sterile inflammation, however, the underlying molecular basis remains unclear. This work aimed to investigate the role of ER-mitochondria communication during ER stress-induced NLRP3 inflammasome activation in both peripheral and central innate immune systems, by using THP-1 human monocytes and BV2 microglia cells, respectively, as in vitro models. Markers of ER stress, mitochondrial dynamics and mass, as well as NLRP3 inflammasome activation were evaluated by Western Blot, IL-1ß secretion was measured by ELISA, and ER-mitochondria contacts were quantified by transmission electron microscopy. Mitochondrial Ca2+ uptake and polarization were analyzed with fluorescent probes, and measurement of aconitase and SOD2 activities monitored mitochondrial ROS accumulation. ER stress was demonstrated to activate the NLRP3 inflammasome in both peripheral and central immune cells. Studies in monocytes indicate that ER stress-induced NLRP3 inflammasome activation occurs by a Ca2+-dependent and ROS-independent mechanism, which is coupled with upregulation of MAMs-resident chaperones, closer ER-mitochondria contacts, as well as mitochondrial depolarization and impaired dynamics. Moreover, enhanced ER stress-induced NLRP3 inflammasome activation in the immune system was found associated with pathological conditions since it was observed in monocytes derived from bipolar disorder (BD) patients, supporting a pro-inflammatory status in BD. In conclusion, by demonstrating that ER-mitochondria communication plays a key role in the response of the innate immune cells to ER stress, this work contributes to elucidate the molecular mechanisms underlying NLRP3 inflammasome activation under stress conditions, and to disclose novel potential therapeutic targets for diseases associated with sterile inflammation.
Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Estresse do Retículo Endoplasmático , Humanos , Sistema Imunitário , MitocôndriasRESUMO
Dementia, especially Alzheimer's Disease (AD) and vascular dementia, is a major public health problem that continues to expand in both economically emerging and hegemonic countries. In 2017, the World Alzheimer Report estimated that over 50 million people were living with dementia globally. Metabolic dysfunctions of brain structures such as the hippocampus and cerebral cortex have been implicated as risk factors for dementia. Several well-defined metabolic risk factors for AD include visceral obesity, chronic inflammation, peripheral and brain insulin resistance, type 2 diabetes mellitus (T2DM), hypercholesterolemia, and others. In this review, we describe the relationship between the dysmetabolic mechanisms, although still unknown, and dementia, particularly AD. Adiponectin (ADPN), the most abundant circulating adipocytokine, acts as a protagonist in the metabolic dysfunction associated with AD, with unexpected and intriguing dual biological functions. This contradictory role of ADPN has been termed the adiponectin paradox. Some evidence suggests that the adiponectin paradox is important in amyloidogenic evolvability in AD. We present cumulative evidence showing that AD and T2DM share many common features. We also review the mechanistic pathways involving brain insulin resistance. We discuss the importance of the evolvability of amyloidogenic proteins (APs), defined as the capacity of a system for adaptive evolution. Finally, we describe potential therapeutic strategies in AD, based on the adiponectin paradox.
Assuntos
Doença de Alzheimer , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Humanos , Doença de Alzheimer/metabolismo , Adiponectina/uso terapêutico , Diabetes Mellitus Tipo 2/metabolismo , Encéfalo/metabolismoRESUMO
E. globulus leaves have been mainly exploited for essential oil recovery or for energy generation in industrial pulp mills, neglecting the abundance of valuable families of extractives, namely, triterpenic acids, that might open new ways for the integrated valorization of this biomass. Therefore, this study highlights the lipophilic characterization of E. globulus leaves before and after hydrodistillation, aiming at the integrated valorization of both essential oils and triterpenic acids. The lipophilic composition of E. globulus leaves after hydrodistillation is reported for the first time. Extracts were obtained by dichloromethane Soxhlet extraction and analyzed by gas chromatography-mass spectrometry. In addition, their cytotoxicity on different cell lines representative of the innate immune system, skin, liver, and intestine were evaluated. Triterpenic acids, such as betulonic, oleanolic, betulinic and ursolic acids, were found to be the main components of these lipophilic extracts, ranging from 30.63-37.14 g kg-1 of dry weight (dw), and representing 87.7-89.0% w/w of the total content of the identified compounds. In particular, ursolic acid was the major constituent of all extracts, representing 46.8-50.7% w/w of the total content of the identified compounds. Other constituents, such as fatty acids, long-chain aliphatic alcohols and ß-sitosterol were also found in smaller amounts in the studied extracts. This study also demonstrates that the hydrodistillation process does not affect the recovery of compounds of greatest interest, namely, triterpenic acids. Therefore, the results establish that this biomass residue can be considered as a promising source of value-added bioactive compounds, opening new strategies for upgrading pulp industry residues within an integrated biorefinery context.
Assuntos
Eucalyptus , Óleos Voláteis , Triterpenos , Eucalyptus/química , Ácidos Graxos , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Álcoois , Triterpenos/farmacologia , Triterpenos/químicaRESUMO
Peroxiredoxin 3 (PRDX3) belongs to a superfamily of peroxidases that function as protective antioxidant enzymes. Among the six isoforms (PRDX1-PRDX6), PRDX3 is the only protein exclusively localized to the mitochondria, which are the main source of reactive oxygen species. Excessive levels of reactive oxygen species are harmful to cells, inducing mitochondrial dysfunction, DNA damage, lipid and protein oxidation and ultimately apoptosis. Neuronal cell damage induced by oxidative stress has been associated with numerous neurodegenerative disorders including Alzheimer's and Parkinson's diseases. Leveraging the large aggregation of genomic ataxia datasets from the PREPARE (Preparing for Therapies in Autosomal Recessive Ataxias) network, we identified recessive mutations in PRDX3 as the genetic cause of cerebellar ataxia in five unrelated families, providing further evidence for oxidative stress in the pathogenesis of neurodegeneration. The clinical presentation of individuals with PRDX3 mutations consists of mild-to-moderate progressive cerebellar ataxia with concomitant hyper- and hypokinetic movement disorders, severe early-onset cerebellar atrophy, and in part olivary and brainstem degeneration. Patient fibroblasts showed a lack of PRDX3 protein, resulting in decreased glutathione peroxidase activity and decreased mitochondrial maximal respiratory capacity. Moreover, PRDX3 knockdown in cerebellar medulloblastoma cells resulted in significantly decreased cell viability, increased H2O2 levels and increased susceptibility to apoptosis triggered by reactive oxygen species. Pan-neuronal and pan-glial in vivo models of Drosophila revealed aberrant locomotor phenotypes and reduced survival times upon exposure to oxidative stress. Our findings reveal a central role for mitochondria and the implication of oxidative stress in PRDX3 disease pathogenesis and cerebellar vulnerability and suggest targets for future therapeutic approaches.
Assuntos
Ataxia Cerebelar/genética , Estresse Oxidativo/genética , Peroxirredoxina III/genética , Adulto , Animais , Ataxia Cerebelar/metabolismo , Ataxia Cerebelar/patologia , Drosophila , Feminino , Humanos , Mutação com Perda de Função , Masculino , Pessoa de Meia-Idade , LinhagemRESUMO
Plants must adapt to cope with adverse environmental conditions that affect their growth and development. To overcome these constraints, they can alter their developmental patterns by modulating cellular processes and activating stress-responsive signals. Alongside the activation of the antioxidant (AOX) system, a high number of genes are expressed, and proteins must be distributed to the correct locations within the cell. The endomembrane system and associated vesicles thus play an important role. Several pathways have been associated with adverse environmental conditions, which is the case for the exocyst-positive organelle-EXPO. The present work, using Arabidopsis mutants with T-DNA insertions in the gene EXO70, essential for EXPO vesicles formation, was designed to characterise the anatomical (morphology and root length), biochemical (quantification of stress markers and antioxidant system components), and molecular responses (gene expression) to abiotic stresses (saline, drought, oxidative, and metal-induced toxicity). The results obtained showed that mutant plants behave differently from the wild type (WT) plants. Therefore, in the exo70 mutant, morphological changes were more noticeable in plants under stress, and the non-enzymatic component of the antioxidant system was activated, with no alterations to the enzymatic component. Furthermore, other defence strategies, such as autophagy, did not show important changes. These results confirmed the EXPO as an important structure for tolerance/adaptation to stress.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Antioxidantes/metabolismo , Citoplasma/metabolismo , Estresse Fisiológico/genética , Homeostase/genética , Plantas Geneticamente Modificadas/metabolismo , Secas , Regulação da Expressão Gênica de PlantasRESUMO
Alzheimer's disease (AD) is the most common neurodegenerative disorder affecting elderly people worldwide. Currently, there are no effective treatments for AD able to prevent disease progression, highlighting the urgency of finding new therapeutic strategies to stop or delay this pathology. Several plants exhibit potential as source of safe and multi-target new therapeutic molecules for AD treatment. Meanwhile, Eucalyptus globulus extracts revealed important pharmacological activities, namely antioxidant and anti-inflammatory properties, which can contribute to the reported neuroprotective effects. This review summarizes the chemical composition of essential oil (EO) and phenolic extracts obtained from Eucalyptus globulus leaves, disclosing major compounds and their effects on AD-relevant pathological features, including deposition of amyloid-ß (Aß) in senile plaques and hyperphosphorylated tau in neurofibrillary tangles (NFTs), abnormalities in GABAergic, cholinergic and glutamatergic neurotransmission, inflammation, and oxidative stress. In general, 1,8-cineole is the major compound identified in EO, and ellagic acid, quercetin, and rutin were described as main compounds in phenolic extracts from Eucalyptus globulus leaves. EO and phenolic extracts, and especially their major compounds, were found to prevent several pathological cellular processes and to improve cognitive function in AD animal models. Therefore, Eucalyptus globulus leaves are a relevant source of biological active and safe molecules that could be used as raw material for nutraceuticals and plant-based medicinal products useful for AD prevention and treatment.
Assuntos
Doença de Alzheimer , Óleos Voláteis , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Animais , Biomassa , Florestas , Humanos , Óleos Voláteis/farmacologia , Óleos Voláteis/uso terapêutico , Fenóis/farmacologiaRESUMO
Nonalcoholic fatty liver disease (NAFLD), a condition strongly associated with obesity and insulin resistance, is characterized by hepatic lipid accumulation and activation of the endoplasmic reticulum (ER) stress response. The sirtuin 2 (SIRT2) protein deacetylase is emerging as a new player in metabolic homeostasis, but its role in the development of hepatic steatosis and its link with ER stress activation remains unknown. SIRT2-knockout (SIRT2-KO) and wild-type mice were fed either a control or a high-fat diet (HFD) for 4 weeks. Genetic manipulation of SIRT2 levels was performed in human hepatic cells. Although apparently normal under a control diet, SIRT2-KO mice showed accelerated body weight gain and adiposity on a HFD, accompanied by severe insulin resistance. Importantly, SIRT2-KO mice exhibited worsened hepatic steatosis independently from diet, consistent with upregulated gene expression of lipogenic enzymes and increased expression of ER stress markers. Exposure of hepatic cells to palmitate induced lipid accumulation, increased ER stress, and decreased SIRT2 expression. Moreover, SIRT2-silenced cells showed enhanced lipid accumulation and ER stress activation under basal conditions, whereas SIRT2 overexpression abrogated palmitate-induced lipid deposition and ER stress activation. Our findings reveal a role for SIRT2 in the regulation of hepatic lipid homeostasis, potentially through the ER stress response, suggesting that SIRT2 activation might constitute a therapeutic strategy against obesity and its metabolic complications.
Assuntos
Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Sirtuína 2/metabolismo , Animais , Dieta Hiperlipídica , Estresse do Retículo Endoplasmático/fisiologia , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/complicações , Obesidade/genética , Obesidade/metabolismo , Palmitatos/metabolismo , Sirtuína 2/genéticaRESUMO
Parkinson's disease (PD) is a progressive neurodegenerative disorder, for which no disease-modifying therapies are available to date. Although understanding of the precise aetiology of PD is incomplete, it is clear that age, genetic predisposition and environmental stressors increase the risk. At the cellular level, oxidative stress, chronic neuroinflammation, mitochondrial dysfunction and aberrant protein aggregation have been implicated as contributing factors. These detrimental processes are counteracted by elaborate networks of cellular defence mechanisms, one of which is orchestrated by transcription factor nuclear factor-erythroid 2 p45-related factor 2 (Nrf2; gene name NFE2L2). A wealth of preclinical evidence suggests that Nrf2 activation is beneficial in cellular and animal models of PD. In this review, we summarise the current understanding of mitochondrial dysfunction in PD, the role of Nrf2 in mitochondrial function and explore the potential of Nrf2 as a therapeutic target for mitochondrial dysfunction in PD.
Assuntos
Fator 2 Relacionado a NF-E2 , Doença de Parkinson , Animais , Regulação da Expressão Gênica , Mitocôndrias/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Doença de Parkinson/genéticaRESUMO
Alzheimer's disease (AD) is one of the most common forms of dementia in the elderly. Currently, there are over 50 million cases of dementia worldwide and it is expected that it will reach 136 million by 2050. AD is described as a neurodegenerative disease that gradually compromises memory and learning capacity. Patients often exhibit brain glucose hypometabolism and are more susceptible to develop type 2 diabetes or insulin resistance in comparison with age-matched controls. This suggests that there is a link between both pathologies. Glucose metabolism and the tricarboxylic acid cycle are tightly related to mitochondrial performance and energy production. Impairment of both these pathways can evoke oxidative damage on mitochondria and key proteins linked to several hallmarks of AD. Glycation is also another type of post-translational modification often reported in AD, which might impair the function of proteins that participate in metabolic pathways thought to be involved in this illness. Despite needing further research, therapies based on insulin treatment, usage of anti-diabetes drugs or some form of dietary intervention, have shown to be promising therapeutic approaches for AD in its early stages of progression and will be unveiled in this paper.
Assuntos
Doença de Alzheimer/terapia , Encéfalo/metabolismo , Glucose/metabolismo , Insulina/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Encéfalo/patologia , Ciclo do Ácido Cítrico/genética , Humanos , Insulina/metabolismo , Resistência à Insulina/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Estresse Oxidativo/genéticaRESUMO
Glioblastoma (GBM) is the most common adult primary tumor of the CNS characterized by rapid growth and diffuse invasiveness into the brain parenchyma. The GBM resistance to chemotherapeutic drugs may be due to the presence of cancer stem cells (CSCs). The CSCs activate the same molecular pathways as healthy stem cells such as WNT, Sonic hedgehog (SHH), and Notch. Mutations or deregulations of those pathways play a key role in the proliferation and differentiation of their surrounding environment, leading to tumorigenesis. Here we investigated the effect of SHH signaling pathway inhibition in human GBM cells by using GANT-61, considering stem cell phenotype, cell proliferation, and cell death. Our results demonstrated that GANT-61 induces apoptosis and autophagy in GBM cells, by increasing the expression of LC3 II and cleaved caspase 3 and 9. Moreover, we observed that SHH signaling plays a crucial role in CSC phenotype maintenance, being also involved in the epithelial-mesenchymal transition (EMT) phenotype. We also noted that SHH pathway modulation can regulate cell proliferation as revealed through the analysis of Ki-67 and c-MYC expressions. We concluded that SHH signaling pathway inhibition may be a promising therapeutic approach to treat patients suffering from GBM refractory to traditional treatments.
Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Piridinas/farmacologia , Pirimidinas/farmacologia , Apoptose/fisiologia , Autofagia/fisiologia , Neoplasias Encefálicas/patologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/fisiologia , Glioblastoma/patologia , Proteínas Hedgehog/metabolismo , Humanos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismoRESUMO
Bipolar disorder (BD) is a chronic and cyclic mental disorder, characterized by unusual mood swings between mania/hypomania and depression, raising concern in both scientific and medical communities due to its deleterious social and economic impact. Polypharmacy is the rule due to the partial effectiveness of available drugs. Disease course is often unremitting, resulting in frequent cognitive deficits over time. Despite all research efforts in identifying BD-associated molecular mechanisms, current knowledge remains limited. However, the involvement of inflammation in BD pathophysiology is increasingly consensual, with the immune system and neuroinflammation playing a key role in disease course. Evidence includes altered levels of cytokines and acute-phase proteins, pathological microglial activation, deregulation of Nrf2-Keap1 system and changes in biogenic amines neurotransmitters, whose expression is regulated by TNF-α, a pro-inflammatory cytokine highly involved in BD, pointing out inflammation as a novel and attractive therapeutic target for BD. As result, new therapeutic agents including non-steroidal anti-inflammatory drugs, N-acetylcysteine and GSK3 inhibitors have been incorporated in BD treatment. Taking into consideration the latest pre-clinical and clinical trials, in this review we discuss recent data regarding inflammation in BD, unveiling potential therapeutic approaches through direct or indirect modulation of inflammatory response.
Assuntos
Anti-Inflamatórios/uso terapêutico , Transtorno Bipolar/tratamento farmacológico , Inflamação/tratamento farmacológico , Animais , HumanosRESUMO
OBJECTIVE: To analyze the temporal evolution of the pattern of hospital use in the context of the COVID-19 pandemic in Brazil. METHODS: This retrospective observational study compared hospital use and mortality in the Brazilian Unified Health System (SUS) in the first six months of the COVID-19 pandemic with the year before the onset of the pandemic in six Brazilian capitals (São Paulo, Rio de Janeiro, Manaus, Fortaleza, Recife, and Brasilia). It was based on secondary administrative data from the SUS Hospital Information System (SIH), focusing on the number of hospitalizations per fortnight, age, and gender of patients, hospital length of stay, and the proportions of surgical, elective, with the use of ICU, and resulting in death hospitalizations. It also compared the number of hospitalizations and mortality related to frequent diagnostic groups. RESULTS: A significant drop was identified in the number of hospitalizations as of March 2020, with the first peak of COVID-19 hospitalizations in five capitals recorded in May 2020. In the six capitals, we observed significant reductions in the mean number of hospitalizations per fortnight from the beginning of the pandemic. We also identified an increase in the mean age of the patients and the proportion of male patients. The proportion of surgical and elective hospitalizations dropped significantly in all capitals, while the proportion of hospitalizations with ICU use increased significantly. Significant increases in-hospital mortality were also recorded in the six capitals with the pandemic, including or excluding COVID-19 hospitalizations from the comparison. CONCLUSION: The pandemic caused changes in the pattern of use and hospital indicators in the first six months in the cities considered, evidencing the need for attention to diseases with a hospital production altered by the COVID-19 course and health system performance problems in the face of challenges.