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1.
Adv Sci (Weinh) ; : e2403963, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38924362

RESUMO

Ferroptosis is a form of regulated cell death that can be modulated by small molecules and has the potential for the development of therapeutics for oncology. Although excessive lipid peroxidation is the defining hallmark of ferroptosis, DNA damage may also play a significant role. In this study, a potential mechanistic role for MIF in homologous recombination (HR) DNA repair is identified. The inhibition or genetic depletion of MIF or other HR proteins, such as breast cancer type 1 susceptibility protein (BRCA1), is demonstrated to significantly enhance the sensitivity of cells to ferroptosis. The interference with HR results in the translocation of the tumor suppressor protein p53 to the mitochondria, which in turn stimulates the production of reactive oxygen species. Taken together, the findings demonstrate that MIF-directed small molecules enhance ferroptosis via a putative MIF-BRCA1-RAD51 axis in HR, which causes resistance to ferroptosis. This suggests a potential novel druggable route to enhance ferroptosis by targeted anticancer therapeutics in the future.

2.
Cells ; 13(10)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38786065

RESUMO

In various neurodegenerative conditions, inflammation plays a significant role in disrupting the blood-brain barrier (BBB), contributing to disease progression. Nitric oxide (NO) emerges as a central regulator of vascular function, with a dual role in inflammation, acting as both a pro- and anti-inflammatory molecule. This study investigates the effects of the NO donor sodium nitroprusside (SNP) in protecting the BBB from lipopolysaccharide (LPS)-induced inflammation, using bEnd.3 endothelial cells as a model system. Additionally, Raw 264.7 macrophages were employed to assess the effects of LPS and SNP on their adhesion to a bEnd.3 cell monolayer. Our results show that LPS treatment induces oxidative stress, activates the JAK2/STAT3 pathway, and increases pro-inflammatory markers. SNP administration effectively mitigates ROS production and IL-6 expression, suggesting a potential anti-inflammatory role. However, SNP did not significantly alter the adhesion of Raw 264.7 cells to bEnd.3 cells induced by LPS, probably because it did not have any effect on ICAM-1 expression, although it reduced VCAM expression. Moreover, SNP did not prevent BBB disruption. This research provides new insights into the role of NO in BBB disruption induced by inflammation.


Assuntos
Barreira Hematoencefálica , Inflamação , Lipopolissacarídeos , Nitroprussiato , Lipopolissacarídeos/farmacologia , Nitroprussiato/farmacologia , Animais , Camundongos , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Células RAW 264.7 , Inflamação/patologia , Espécies Reativas de Oxigênio/metabolismo , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Estresse Oxidativo/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Adesão Celular/efeitos dos fármacos , Interleucina-6/metabolismo , Transdução de Sinais/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
3.
Biochimie ; 219: 118-129, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37993054

RESUMO

Breast cancer is the most prevalent cancer in women. Metabolic abnormalities, particularly increased lipid synthesis and uptake, impact the onset and progression of the disease. However, the influence of lipid metabolism in breast cancer varies according to the disease stage and patient's hormone status. In postmenopausal patients, obesity is associated with a higher risk and poor prognosis of luminal tumors, while in premenopausal individuals, it is correlated to BRCA mutated tumors. In fact, the tumor's lipid profile may be used to distinguish between HER2+, luminal and BRCA-mutated tumors. Moreover, drug resistance was associated with increased fatty acid synthesis and alterations in membrane composition, impacting its fluidity and spatial subdomains such as lipid rafts. Here, we discuss the subtype-specific lipid metabolism alterations found in breast cancer and the potentiality of its modulation in a clinical setting.


Assuntos
Neoplasias da Mama , Feminino , Humanos , Neoplasias da Mama/metabolismo , Lipídeos , Obesidade/complicações , Receptor ErbB-2/metabolismo , Receptores de Progesterona/metabolismo , Transdução de Sinais
4.
Neurobiol Dis ; 191: 106389, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38142840

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disease which accounts for the most cases of dementia worldwide. Impaired memory, including acquisition, consolidation, and retrieval, is one of the hallmarks in AD. At the cellular level, dysregulated synaptic plasticity partly due to reduced long-term potentiation (LTP) and enhanced long-term depression (LTD) underlies the memory deficits in AD. GluA3 containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are one of key receptors involved in rapid neurotransmission and synaptic plasticity. Recent studies revealed a novel form of GluA3 involved in neuronal plasticity that is dependent on cyclic adenosine monophosphate (cAMP), rather than N-methyl-d-aspartate (NMDA). However, this cAMP-dependent GluA3 pathway is specifically and significantly impaired by amyloid beta (Aß), a pathological marker of AD. cAMP is a key second messenger that plays an important role in modulating memory and synaptic plasticity. We previously reported that exchange protein directly activated by cAMP 2 (Epac2), acting as a main cAMP effector, plays a specific and time-limited role in memory retrieval. From electrophysiological perspective, Epac2 facilities the maintenance of LTP, a cellular event closely associated with memory retrieval. Additionally, Epac2 was found to be involved in the GluA3-mediated plasticity. In this review, we comprehensively summarize current knowledge regarding the specific roles of GluA3 and Epac2 in synaptic plasticity and memory, and their potential association with AD.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Humanos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Plasticidade Neuronal/fisiologia , Potenciação de Longa Duração/fisiologia , Transtornos da Memória , Hipocampo/metabolismo
5.
Cell Death Dis ; 14(11): 772, 2023 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-38007529

RESUMO

Ferroptosis is an iron- and reactive oxygen species (ROS)-dependent form of regulated cell death, that has been implicated in Alzheimer's disease and Parkinson's disease. Inhibition of cystine/glutamate antiporter could lead to mitochondrial fragmentation, mitochondrial calcium ([Ca2+]m) overload, increased mitochondrial ROS production, disruption of the mitochondrial membrane potential (ΔΨm), and ferroptotic cell death. The observation that mitochondrial dysfunction is a characteristic of ferroptosis makes preservation of mitochondrial function a potential therapeutic option for diseases associated with ferroptotic cell death. Mitochondrial calcium levels are controlled via the mitochondrial calcium uniporter (MCU), the main entry point of Ca2+ into the mitochondrial matrix. Therefore, we have hypothesized that negative modulation of MCU complex may confer protection against ferroptosis. Here we evaluated whether the known negative modulators of MCU complex, ruthenium red (RR), its derivative Ru265, mitoxantrone (MX), and MCU-i4 can prevent mitochondrial dysfunction and ferroptotic cell death. These compounds mediated protection in HT22 cells, in human dopaminergic neurons and mouse primary cortical neurons against ferroptotic cell death. Depletion of MICU1, a [Ca2+]m gatekeeper, demonstrated that MICU is protective against ferroptosis. Taken together, our results reveal that negative modulation of MCU complex represents a therapeutic option to prevent degenerative conditions, in which ferroptosis is central to the progression of these pathologies.


Assuntos
Cálcio , Ferroptose , Animais , Humanos , Camundongos , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Neurônios Dopaminérgicos/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Espécies Reativas de Oxigênio/metabolismo
6.
Trends Pharmacol Sci ; 44(12): 917-933, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37783643

RESUMO

Exposure to environmental pollutants contributes to diverse pathologies, including pulmonary disease, lower respiratory infections, cancer, and stroke. Pollutants' entry can occur through inhalation, traversing endothelial and epithelial barriers, and crossing the blood-brain barrier, leading to a wide distribution throughout the human body via systemic circulation. Pollutants cause cellular damage by multiple mechanisms encompassing oxidative stress, mitochondrial dysfunction, (neuro)inflammation, and protein instability/proteotoxicity. Sensing pollutants has added a new dimension to disease progression and drug failure. Understanding the molecular pathways and potential receptor binding/signaling that underpin 'sensing' could contribute to ways to combat the detrimental effects of pollutants. We highlight key points of pollutant signaling, crosstalk with receptors acting as drug targets for chronic diseases, and discuss the potential for future therapeutics.


Assuntos
Poluentes Ambientais , Humanos , Poluentes Ambientais/toxicidade , Inflamação , Estresse Oxidativo
7.
Sci Rep ; 13(1): 10622, 2023 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-37391534

RESUMO

Tumor necrosis factor alpha (TNF-α) and its key role in modulating immune responses has been widely recognized as a therapeutic target for inflammatory and neurodegenerative diseases. Even though inhibition of TNF-α is beneficial for the treatment of certain inflammatory diseases, total neutralization of TNF-α largely failed in the treatment of neurodegenerative diseases. TNF-α exerts distinct functions depending on interaction with its two TNF receptors, whereby TNF receptor 1 (TNFR1) is associated with neuroinflammation and apoptosis and TNF receptor 2 (TNFR2) with neuroprotection and immune regulation. Here, we investigated the effect of administering the TNFR1-specific antagonist Atrosimab, as strategy to block TNFR1 signaling while maintaining TNFR2 signaling unaltered, in an acute mouse model for neurodegeneration. In this model, a NMDA-induced lesion that mimics various hallmarks of neurodegenerative diseases, such as memory loss and cell death, was created in the nucleus basalis magnocellularis and Atrosimab or control protein was administered centrally. We showed that Atrosimab attenuated cognitive impairments and reduced neuroinflammation and neuronal cell death. Our results demonstrate that Atrosimab is effective in ameliorating disease symptoms in an acute neurodegenerative mouse model. Altogether, our study indicates that Atrosimab may be a promising candidate for the development of a therapeutic strategy for the treatment of neurodegenerative diseases.


Assuntos
Doenças Neurodegenerativas , Receptores Tipo II do Fator de Necrose Tumoral , Receptores Tipo I de Fatores de Necrose Tumoral , Animais , Camundongos , Modelos Animais de Doenças , Transtornos da Memória/tratamento farmacológico , Doenças Neuroinflamatórias , Receptores Tipo I de Fatores de Necrose Tumoral/antagonistas & inibidores , Fator de Necrose Tumoral alfa , Doenças Neurodegenerativas/tratamento farmacológico
8.
Sci Rep ; 13(1): 5670, 2023 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-37024614

RESUMO

Idiopathic pulmonary fibrosis is a progressive lung disease that causes scarring and loss of lung function. Macrophages play a key role in fibrosis, but their responses to altered morphological and mechanical properties of the extracellular matrix in fibrosis is relatively unexplored. Our previous work showed functional changes in murine fetal liver-derived alveolar macrophages on fibrous or globular collagen morphologies. In this study, we applied differential proteomics to further investigate molecular mechanisms underlying the observed functional changes. Macrophages cultured on uncoated, fibrous, or globular collagen-coated plastic were analyzed by liquid chromatography-mass spectrometry. The presence of collagen affected expression of 77 proteins, while 142 were differentially expressed between macrophages grown on fibrous or globular collagen. Biological process and pathway enrichment analysis revealed that culturing on any type of collagen induced higher expression of enzymes involved in glycolysis. However, this did not lead to a higher rate of glycolysis, probably because of a concomitant decrease in activity of these enzymes. Our data suggest that macrophages sense collagen morphologies and can respond with changes in expression and activity of metabolism-related proteins. These findings suggest intimate interactions between macrophages and their surroundings that may be important in repair or fibrosis of lung tissue.


Assuntos
Colágeno Tipo I , Proteômica , Camundongos , Animais , Colágeno Tipo I/metabolismo , Proteômica/métodos , Colágeno/metabolismo , Macrófagos/metabolismo , Fibrose
9.
Int J Mol Sci ; 24(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36675159

RESUMO

Dysfunction of the immune system and mitochondrial metabolism has been associated with Parkinson's disease (PD) pathology. Mutations and increased kinase activity of leucine-rich repeat kinase 2 (LRRK2) are linked to both idiopathic and familial PD. However, the function of LRRK2 in the immune cells under inflammatory conditions is contradictory. Our results showed that lipopolysaccharide (LPS) stimulation increased the kinase activity of LRRK2 in parental RAW 264.7 (WT) cells. In addition to this, LRRK2 deletion in LRRK2 KO RAW 264.7 (KO) cells altered cell morphology following LPS stimulation compared to the WT cells, as shown by an increase in the cell impedance as observed by the xCELLigence measurements. LPS stimulation caused an increase in the cellular reactive oxygen species (ROS) levels in both WT and KO cells. However, WT cells displayed a higher ROS level compared to the KO cells. Moreover, LRRK2 deletion led to a reduction in interleukin-6 (IL-6) inflammatory cytokine and cyclooxygenase-2 (COX-2) expression and an increase in lactate production after LPS stimulation compared to the WT cells. These data illustrate that LRRK2 has an effect on inflammatory processes in RAW macrophages upon LPS stimulation.


Assuntos
Lipopolissacarídeos , Transdução de Sinais , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Lipopolissacarídeos/farmacologia , Espécies Reativas de Oxigênio , Macrófagos/metabolismo , Mutação
10.
Int J Biol Macromol ; 224: 584-593, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36273544

RESUMO

Several polysaccharides are considered to be "biological response modifiers" (BRM) - these refer to biomolecules that augment immune responses and can be derived from a variety of sources. Microalgae produce a diverse range of polysaccharides and could be an excellent source of BRM. Here, we describe the chemical structure and biological activity of water-soluble polysaccharide isolated from the marine diatom Conticribra weissflogii. Using chemical and NMR spectroscopic methods, the polysaccharide was identified as a (1 â†’ 3)-linked ß-D-glucan with a low proportion of C-6 substitution by single ß-glucose units. The biological activity of this low molecular weight ß-glucan (11.7 kDa) was investigated with respect to glioblastoma cell lines (U87 MG and U251) and macrophages (RAW 264.7). We observed that this ß-D-glucan did not exhibit cytotoxic activity against glioblastoma cells, but did enhance the phagocytic activity of macrophages, suggesting that it possesses immunomodulatory properties.


Assuntos
Diatomáceas , Glioblastoma , beta-Glucanas , Humanos , Glucanos/química , Polissacarídeos/química , beta-Glucanas/química , Fatores Imunológicos
11.
Int J Mol Sci ; 23(12)2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35742966

RESUMO

Glioblastoma multiforme (GBM) is the most aggressive brain tumor in adults. In addition to genetic causes, the tumor microenvironment (TME), including stiffening of the extracellular matrix (ECM), is a main driver of GBM progression. Mechano-transduction and the unfolded protein response (UPR) are essential for tumor-cell adaptation to harsh TME conditions. Here, we studied the effect of a variable stiff ECM on the morphology and malignant properties of GBM stem cells (GSCs) and, moreover, examined the possible involvement of the UPR sensor PERK herein. For this, stiffness-tunable human blood plasma (HBP)/alginate hydrogels were generated to mimic ECM stiffening. GSCs showed stiffness-dependent adaptation characterized by elongated morphology, increased proliferation, and motility which was accompanied by F-Actin cytoskeletal remodeling. Interestingly, in PERK-deficient GSCs, stiffness adaptation was severely impaired, which was evidenced by low F-Actin levels, the absence of F-Actin remodeling, and decreased cell proliferation and migration. This impairment could be linked with Filamin-A (FLN-A) expression, a known interactor of PERK, which was strongly reduced in PERK-deficient GSCs. In conclusion, we identified a novel PERK/FLNA/F-Actin mechano-adaptive mechanism and found a new function for PERK in the cellular adaptation to ECM stiffening.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Actinas/metabolismo , Adulto , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Glioblastoma/metabolismo , Humanos , Microambiente Tumoral , Resposta a Proteínas não Dobradas
12.
Cells ; 11(6)2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35326443

RESUMO

This study addresses the eventual consequence of cytochrome c oxidase (CytOx) inhibition by ATP at high ATP/ADP ratio in isolated rat heart mitochondria. Earlier, it has been demonstrated that the mechanism of allosteric ATP inhibition of CytOx is one of the key regulations of mitochondrial functions. It is relevant that aiming to maintain a high ATP/ADP ratio for the measurement of CytOx activity effectuating the enzymatic inhibition as well as mitochondrial respiration, optimal concentration of mitochondria is critically important. Likewise, only at this concentration, were the differences in ΔΨm and ROS concentrations measured under various conditions significant. Moreover, when CytOx activity was inhibited in the presence of ATP, mitochondrial respiration and ΔΨm both remained static, while the ROS production was markedly decreased. Consubstantial results were found when the electron transport chain was inhibited by antimycin A, letting only CytOx remain functional to support the energy production. This seems to corroborate that the decrease in mitochondrial ROS production is solely the effect of ATP binding to CytOx which results in static respiration as well as membrane potential.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons , Mitocôndrias Cardíacas , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias Cardíacas/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo
13.
J Inflamm Res ; 15: 509-531, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35115803

RESUMO

PURPOSE: Previously, we have shown that CyPPA (cyclohexyl-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-pyrimidin-4-yl]-amine), a pharmacological small-conductance calcium-activated potassium (SK)-channel positive modulator, antagonizes lipopolysaccharide (LPS)-induced cytokine expression in microglial cells. Here, we aimed to test its therapeutic potential for brain-controlled sickness symptoms, brain inflammatory response during LPS-induced systemic inflammation, and peripheral metabolic pathways in mice. METHODS: Mice were pretreated with CyPPA (15 mg/kg IP) 24 hours before and simultaneously with LPS stimulation (2.5 mg/kg IP), and the sickness response was recorded by a telemetric system for 24 hours. A second cohort of mice were euthanized 2 hours after CyPPA or solvent treatment to assess underlying CyPPA-induced mechanisms. Brain, blood, and liver samples were analyzed for inflammatory mediators or nucleotide concentrations using immunohistochemistry, real-time PCR and Western blot, or HPLC. Moreover, we investigated CyPPA-induced changes of UCP1 expression in brown adipose tissue (BAT)-explant cultures. RESULTS: CyPPA treatment did not affect LPS-induced fever, anorexia, adipsia, or expression profiles of inflammatory mediators in the hypothalamus or plasma or microglial reactivity to LPS (CD11b staining and CD68 mRNA expression). However, CyPPA alone induced a rise in core body temperature linked to heat production via altered metabolic pathways like reduced levels of adenosine, increased protein content, and increased UCP1 expression in BAT-explant cultures, but no alteration in ATP/ADP concentrations in the liver. CyPPA treatment was accompanied by altered pathways, including NFκB signaling, in the hypothalamus and cortex, while circulating cytokines remained unaltered. CONCLUSION: Overall, while CyPPA has promise as a treatment strategy, in particular according to results from in vitro experiments, we did not reveal anti-inflammatory effects during severe LPS-induced systemic inflammation. Interestingly, we found that CyPPA alters metabolic pathways inducing short hyperthermia, most likely due to increased energy turnover in the liver and heat production in BAT.

14.
Eur Respir Rev ; 30(161)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34348980

RESUMO

Respiratory diseases are among the leading causes of morbidity and mortality worldwide, representing a major unmet medical need. New chemical entities rarely make it into the clinic to treat respiratory diseases, which is partially due to a lack of adequate predictive disease models and the limited availability of human lung tissues to model respiratory disease. Human pluripotent stem cells (hPSCs) may help fill this gap by serving as a scalable human in vitro model. In addition, human in vitro models of rare genetic mutations can be generated using hPSCs. hPSC-derived epithelial cells and organoids have already shown great potential for the understanding of disease mechanisms, for finding new potential targets by using high-throughput screening platforms, and for personalised treatments. These potentials can also be applied to other hPSC-derived lung cell types in the future. In this review, we will discuss how hPSCs have brought, and may continue to bring, major changes to the field of respiratory diseases by understanding the molecular mechanisms of the pathology and by finding efficient therapeutics.


Assuntos
Células-Tronco Pluripotentes , Diferenciação Celular , Células Epiteliais , Humanos , Pulmão , Organoides
15.
Biochim Biophys Acta Mol Basis Dis ; 1866(6): 165716, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32061776

RESUMO

Thiosulfate sulfurtransferase (TST, EC 2.8.1.1), also known as Rhodanese, is a mitochondrial enzyme which catalyzes the transfer of sulfur in several molecular pathways. After its initial identification as a cyanide detoxification enzyme, it was found that its functions also include sulfur metabolism, modification of iron­sulfur clusters and the reduction of antioxidants glutathione and thioredoxin. TST deficiency was shown to be strongly related to the pathophysiology of metabolic diseases including diabetes and obesity. This review summarizes research related to the enzymatic properties and functions of TST, to then explore the association between the effects of TST on mitochondria and development of diseases such as diabetes and obesity.


Assuntos
Antioxidantes/metabolismo , Doenças Metabólicas/genética , Enxofre/metabolismo , Tiossulfato Sulfurtransferase/genética , Glutationa/metabolismo , Humanos , Proteínas Ferro-Enxofre/genética , Doenças Metabólicas/enzimologia , Doenças Metabólicas/patologia , Selênio/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Tiossulfato Sulfurtransferase/metabolismo
16.
Brain Pathol ; 30(3): 589-602, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31769564

RESUMO

During Alzheimer's disease (AD) progression, microglial cells play complex roles and have potentially detrimental as well as beneficial effects. The use of appropriate model systems is essential for characterizing and understanding the roles of microglia in AD pathology. Here, we used organotypic hippocampal slice cultures (OHSCs) to investigate the impact of microglia on amyloid beta (Aß)-mediated toxicity. Neurons in OHSCs containing microglia were not vulnerable to cell death after 7 days of repeated treatment with Aß1-42 oligomer-enriched preparations. However, when clodronate was used to remove microglia, treatment with Aß1-42 resulted in significant neuronal death. Further investigations indicated signs of endoplasmic reticulum stress and caspase activation after Aß1-42 challenge only when microglia were absent. Interestingly, microglia provided protection without displaying any classic signs of activation, such as an amoeboid morphology or the release of pro-inflammatory mediators (e.g., IL-6, TNF-α, NO). Furthermore, depleting microglia or inhibiting microglial uptake mechanisms resulted in significant more Aß deposition compared to that observed in OHSCs containing functional microglia, suggesting that microglia efficiently cleared Aß. Because inhibiting microglial uptake increased neuronal cell death, the ability of microglia to engulf Aß is thought to contribute to its protective properties. Our study argues for a beneficial role of functional ramified microglia whereby they act against the accumulation of neurotoxic forms of Aß and support neuronal resilience in an in situ model of AD pathology.


Assuntos
Peptídeos beta-Amiloides/farmacologia , Hipocampo/efeitos dos fármacos , Microglia/efeitos dos fármacos , Neuroproteção/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Animais , Caspases/metabolismo , Morte Celular/efeitos dos fármacos , Ácido Clodrônico , Hipocampo/metabolismo , Interleucina-6/metabolismo , Camundongos , Microglia/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
17.
Biochim Biophys Acta Mol Basis Dis ; 1866(3): 165621, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31786336

RESUMO

Lipotoxicity causes hepatic cell death and therefore plays an important role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Metformin, a first-line anti-diabetic drug, has shown a potential protective effect against NAFLD. However, the underlying mechanism is still not clear. In this study, we aim to understand the molecular mechanism of the protective effect of metformin in NAFLD, focusing on lipotoxicity. Cell death was studied in HepG2 cells and primary rat hepatocytes exposed to palmitate and metformin. Metformin ameliorated palmitate-induced necrosis and apoptosis (decreased caspase-3/7 activity by 52% and 57% respectively) in HepG2 cells. Metformin also reduced palmitate-induced necrosis in primary rat hepatocytes (P < 0.05). The protective effect of metformin is not due to reducing intracellular lipid content or activation of AMPK signaling pathways. Metformin and a low concentration (0.1 µmol/L) of rotenone showed moderate inhibition on mitochondrial respiration indicated by reduced basal and maximal mitochondrial respiration and proton leak in HepG2 cells. Moreover, metformin and rotenone (0.1 µmol/L) preserved mitochondrial membrane potential in both HepG2 cells and primary rat hepatocytes. In addition, metformin and rotenone (0.1 µmol/L) also reduces reactive oxygen species (ROS) production and increase superoxide dismutase 2 (SOD2) expression. Our results establish that metformin AMPK-independently protects against palmitate-induced hepatic cell death by moderate inhibition of the mitochondrial respiratory chain, recovering mitochondrial function, decreasing cellular ROS production, and inducing SOD2 expression, indicating that metformin may have beneficial actions beyond its glucose-lowering effect and also suggests that mitochondrial complex І may be a therapeutic target in NAFLD.


Assuntos
Morte Celular/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Metformina/farmacologia , Palmitatos/farmacologia , Substâncias Protetoras/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Células Hep G2 , Hepatócitos/metabolismo , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Necrose/induzido quimicamente , Necrose/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Superóxido Dismutase/metabolismo
18.
Arch Toxicol ; 94(1): 173-186, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31677074

RESUMO

Macrophages play a major role in the removal of foreign materials, including nano-sized materials, such as nanomedicines and other nanoparticles, which they accumulate very efficiently. Because of this, it is recognized that for a safe development of nanotechnologies and nanomedicine, it is essential to investigate potential effects induced by nano-sized materials on macrophages. To this aim, in this work, a recently established model of primary murine alveolar-like macrophages was used to investigate macrophage responses to two well-known nanoparticle models: 50 nm amino-modified polystyrene, known to induce cell death via lysosomal damage and apoptosis in different cell types, and 50 nm silica nanoparticles, which are generally considered non-toxic. Then, a time-resolved study was performed to characterize in detail the response of the macrophages following exposure to the two nanoparticles. As expected, exposure to the amino-modified polystyrene led to cell death, but surprisingly no lysosomal swelling or apoptosis were detected. On the contrary, a peculiar mitochondrial membrane hyperpolarization was observed, accompanied by endoplasmic reticulum stress (ER stress), increased cellular reactive oxygen species (ROS) and changes of metabolic activity, ultimately leading to cell death. Strong toxic responses were observed also after exposure to silica, which included mitochondrial ROS production, mitochondrial depolarization and cell death by apoptosis. Overall, these results showed that exposure to the two nanoparticles led to a very different series of intracellular events, suggesting that the macrophages responded differently to the two nanoparticle models. Similar time-resolved studies are required to characterize the response of macrophages to nanoparticles, as a key parameter in nanosafety assessment.


Assuntos
Macrófagos/efeitos dos fármacos , Nanopartículas/toxicidade , Poliestirenos/toxicidade , Dióxido de Silício/toxicidade , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Células Cultivadas , Difusão Dinâmica da Luz , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/patologia , Macrófagos Alveolares/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Poliestirenos/química , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo
19.
Biochem Pharmacol ; 171: 113714, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31738894

RESUMO

Brain tumours are among the deadliest tumours being highly resistant to currently available therapies. The proliferative behaviour of gliomas is strongly influenced by ion channel activity. Small-conductance calcium-activated potassium (SK/KCa) channels are a family of ion channels that are associated with cell proliferation and cell survival. A combined treatment of classical anti-cancer agents and pharmacological SK channel modulators has not been addressed yet. We used the gold-derivative auranofin to induce cancer cell death by targeting thioredoxin reductases in combination with CyPPA to activate SK channels in neuro- and glioblastoma cells. Combined treatment with auranofin and CyPPA induced massive mitochondrial damage and potentiated auranofin-induced toxicity in neuroblastoma cells in vitro. In particular, mitochondrial integrity, respiration and associated energy generation were impaired. These findings were recapitulated in patient-derived glioblastoma neurospheres yet not observed in non-cancerous HT22 cells. Taken together, integrating auranofin and SK channel openers to affect mitochondrial health was identified as a promising strategy to increase the effectiveness of anti-cancer agents and potentially overcome resistance.


Assuntos
Auranofina/farmacologia , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Neuroblastoma/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia , Canais de Potássio Ativados por Cálcio de Condutância Baixa/agonistas , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Auranofina/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Humanos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neuroblastoma/tratamento farmacológico , Neuroblastoma/patologia , Pirazóis/administração & dosagem , Pirimidinas/administração & dosagem , Canais de Potássio Ativados por Cálcio de Condutância Baixa/metabolismo , Esferoides Celulares/efeitos dos fármacos , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Tiorredoxina Dissulfeto Redutase/metabolismo
20.
Cell Death Dis ; 10(11): 865, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31727879

RESUMO

Evolving concepts on Parkinson's disease (PD) pathology suggest that α-synuclein (aSYN) promote dopaminergic neuron dysfunction and death through accumulating in the mitochondria. However, the consequence of mitochondrial aSYN localisation on mitochondrial structure and bioenergetic functions in neuronal cells are poorly understood. Therefore, we investigated deleterious effects of mitochondria-targeted aSYN in differentiated human dopaminergic neurons in comparison with wild-type (WT) aSYN overexpression and corresponding EGFP (enhanced green fluorescent protein)-expressing controls. Mitochondria-targeted aSYN enhanced mitochondrial reactive oxygen species (ROS) formation, reduced ATP levels and showed severely disrupted structure and function of the dendritic neural network, preceding neuronal death. Transmission electron microscopy illustrated distorted cristae and many fragmented mitochondria in response to WT-aSYN overexpression, and a complete loss of cristae structure and massively swollen mitochondria in neurons expressing mitochondria-targeted aSYN. Further, the analysis of mitochondrial bioenergetics in differentiated dopaminergic neurons, expressing WT or mitochondria-targeted aSYN, elicited a pronounced impairment of mitochondrial respiration. In a pharmacological compound screening, we found that the pan-caspase inhibitors QVD and zVAD-FMK, and a specific caspase-1 inhibitor significantly prevented aSYN-induced cell death. In addition, the caspase inhibitor QVD preserved mitochondrial function and neuronal network activity in the human dopaminergic neurons overexpressing aSYN. Overall, our findings indicated therapeutic effects by caspase-1 inhibition despite aSYN-mediated alterations in mitochondrial morphology and function.


Assuntos
Neurônios Dopaminérgicos/metabolismo , Doença de Parkinson/genética , Serpinas/farmacologia , Proteínas Virais/farmacologia , alfa-Sinucleína/genética , Trifosfato de Adenosina/genética , Caspase 1/genética , Morte Celular/genética , Neurônios Dopaminérgicos/patologia , Regulação da Expressão Gênica , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Consumo de Oxigênio/genética , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/patologia , Espécies Reativas de Oxigênio/metabolismo
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