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Browning of white adipose tissue is hallmarked by increased mitochondrial density and metabolic improvements. However, it remains largely unknown how mitochondrial turnover and quality control are regulated during adipose browning. In the present study, we found that mice lacking adipocyte FoxO1, a transcription factor that regulates autophagy, adopted an alternate mechanism of mitophagy to maintain mitochondrial turnover and quality control during adipose browning. Post-developmental deletion of adipocyte FoxO1 (adO1KO) suppressed Bnip3 but activated Fundc1/Drp1/OPA1 cascade, concurrent with up-regulation of Atg7 and CTSL. In addition, mitochondrial biogenesis was stimulated via the Pgc1α/Tfam pathway in adO1KO mice. These changes were associated with enhanced mitochondrial homeostasis and metabolic health (e.g., improved glucose tolerance and insulin sensitivity). By contrast, silencing Fundc1 or Pgc1α reversed the changes induced by silencing FoxO1, which impaired mitochondrial quality control and function. Ablation of Atg7 suppressed mitochondrial turnover and function, causing metabolic disorder (e.g., impaired glucose tolerance and insulin sensitivity), regardless of elevated markers of adipose browning. Consistently, suppression of autophagy via CTSL by high-fat diet was associated with a reversal of adO1KO-induced benefits. Our data reveal a unique role of FoxO1 in coordinating mitophagy receptors (Bnip3 and Fundc1) for a fine-tuned mitochondrial turnover and quality control, underscoring autophagic clearance of mitochondria as a prerequisite for healthy browning of adipose tissue.
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Resistência à Insulina , Animais , Camundongos , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Obesidade/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismoRESUMO
Particulate matter, represented by soot particles, poses a significant global environmental threat, necessitating efficient control technology. Here, we innovatively designed and elaborately fabricated ordered hierarchical macroporous catalysts of Ce0.8Zr0.2O2 (OM CZO) integrated on a catalyzed diesel particulate filter (CDPF) using the self-assembly method. An oxygen-vacancy-enriched ordered macroporous Ce0.8Zr0.2O2 catalyst (VO-OM CZO) integrated CDPF was synthesized by subsequent NaBH4 reduction. The VO-OM CZO integrated CDPF exhibited a markedly enhanced soot oxidation activity compared to OM CZO and powder CZO coated CDPFs (T50: 430 vs 490 and 545 °C, respectively). The well-defined OM structure of the VO-OM CZO catalysts effectively improves the contact efficiency between soot and the catalysts. Meanwhile, oxygen vacancies trigger the formation of a large amount of highly reactive peroxide species (O22-) from molecular oxygen (O2) through electron abstraction from the three adjacent Ce3+ (3Ce3+ + Vö + O2 â 3Ce4+ + O22-), contributing to the efficient soot oxidation. This work demonstrates the fabrication of the ordered macroporous CZO integrated CDPF and reveals the importance of structure and surface engineering in soot oxidation, which sheds light on the design of highly efficient PM capture and removal devices.
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Oxirredução , Catálise , Peróxidos/química , Fuligem/química , Filtração , Material Particulado/química , Emissões de VeículosRESUMO
Various pharmacological blockers targeting K+ channel have been identified to be related to the treatment of Parkinson's disease (PD). Previous studies showed that 4-Aminopyridine (4-AP), a wide-spectrum K+ channel blocker, was able to attenuate apomorphine-induced rotation in parkinsonism rats, indicating the possible beneficial effects in attenuation of PD motor symptoms. However, it is unclear whether 4-AP exhibits neuroprotective effects against the neurodegeneration of substantia nigra (SN)-striatum system in PD. In this study, the 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mouse model was employed to evaluate the neuroprotective effects of 4-AP. Results showed that 4-AP inhibited MPTP-induced dopaminergic neuronal loss in the SN as well as dopamine depletion in the striatum. Behavior indexes of open field test and rotarod test confirmed that 4-AP attenuated MPTP-induced motor deficits. We also showed that 4-AP treatment could significantly attenuate the MPTP-induced increase in malonaldehyde (MDA) levels and decrease in superoxide dismutase (SOD) levels. Additionally, MPTP significantly reduced the Bcl-2 expression and promoted the Caspase-3 activation; 4-AP protected dopaminergic neurons against MPTP-induced neurotoxicity by reversing these changes. These results indicate that 4-AP exerts a neuroprotective effect on dopaminergic neurons against MPTP by decreasing oxidative stress and apoptosis. This provides a promising therapeutic target for the treatment of PD.
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Intoxicação por MPTP , Fármacos Neuroprotetores , Doença de Parkinson , Animais , Camundongos , Ratos , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/metabolismo , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos , Camundongos Endogâmicos C57BL , Intoxicação por MPTP/tratamento farmacológico , Intoxicação por MPTP/prevenção & controle , Intoxicação por MPTP/induzido quimicamente , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Fármacos Neuroprotetores/metabolismo , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/metabolismo , Substância Negra , 4-Aminopiridina/farmacologiaRESUMO
Taste masking is critical to improving the compliance of pediatric oral dosage forms. However, it is challenging for extremely bitter lisdexamfetamine dimesylate (LDX) with a long half-life and given in large dose. The present study aims to develop an immediate-release, taste-masked lisdexamfetamine chewable tablet. Lisdexamfetamine-resin complexes (LRCs) were prepared using the batch method. The molecular mechanism of taste masking was explored by PXRD, PLM, STA, and FT-IR. The results showed that taste masking was attributed to the ionic interaction between drug and the resin. The ion exchange process conformed to first-order kinetics. The rate-limiting step of drug release was the diffusion of ions inside the particles, and the concentration of H+ was the key factor for immediate release. The masking efficiency of the prepared LRCs in saliva exceeded 96%, and the drug could be completely released within 15 min in aqueous HCl (pH 1.2). Furthermore, the SeDeM expert system was used for the first time to comprehensively study the powder properties of LRCs and to quickly visualize their defects (compressibility, lubricity/stability, and lubricity/dosage). The selection of excipients was targeted rather than traditional screening, thus obtaining a robust chewable tablet formulation suitable for direct compression. Finally, the difference between chewable tablets containing LRCs and chewable tablets containing lisdexamfetamine dimesylate was compared by in vitro dissolution test, electronic tongue, and disintegration test. In conclusion, an immediate-released, child-friendly lisdexamfetamine chewable tablets without bitterness was successfully developed by the QbD approach, using the SeDeM system, which may help in further development of chewable tablets.
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Dimesilato de Lisdexanfetamina , Paladar , Humanos , Criança , Resinas de Troca Iônica/química , Excipientes , Espectroscopia de Infravermelho com Transformada de Fourier , Solubilidade , Comprimidos , Composição de Medicamentos/métodos , Administração OralRESUMO
Conjugated polymers possess better electron conductivity due to large π-electron conjugated configuration endowing them significant scientific and technological interest. However, the obvious deficiency of active-site underutilization impairs their electrochemical performance. Therefore, designing and engineering π-conjugated polymers with rich redox functional groups and mesoporous architectures could offer new opportunities for them in these emerging applications and further expand their application scopes. Herein, a series of 1,3,5-tris(4-aminophenyl) benzene (TAPB)-based π-conjugated mesoporous polymers (π-CMPs) are constructed by one-pot emulsion-induced interface assembly strategy. Furthermore, co-induced in situ polymerization on 2D interfaces by emulsion and micelles is explored, which delivers sandwiched 2D mesoporous π-CMPs-coated graphene oxides (GO@mPTAPB). Benefiting from specific redox-active functional groups, excellent electron conductivity and a 2D mesoporous conjugated framework, GO@mPTAPB exhibits high capability of accommodating Li+ anions (up to 382 mAh g-1 at 0.2 A g-1 ) and outstanding electrochemical stability (87.6% capacity retention after 1000 cycles). The ex situ Raman and impedance spectra are further applied to reveal the high reversibility of GO@mPTAPB. This work will greatly promote the development of advanced π-CMPs-based organic anodes toward energy storage devices.
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An in-depth understanding of the surface properties-activity relationship could provide a fundamental guidance for the design of highly efficient perovskite-based catalysts for the control of anthropogenic methane emission. Herein, both oxygen vacancies and Con+ Lewis acid sites were purposely introduced on ordered macroporous La0.8Sr0.2CoO3 monolithic catalysts by one-step reduction and selective etching in oxalic acid, and their synergistic effect on methane combustion was investigated. Combined with experimental and theoretical investigations, we revealed that the positively charged Con+ Lewis acid sites and single-electron-trapped oxygen vacancies (Vo·) formed an active pair, which enabled an effective localized electron cloud shift from Vo· to Con+. The characteristic electronic effect modulates surface electronic properties and coordination structures, thus resulting in superior oxygen activation capacity, lattice oxygen mobility, and reducibility, as well as favorable CH4 interaction and oxidation. Our work not only gives insights into surface properties-activity relationships on perovskite for hydrocarbon combustion but also sheds substantial light on future environmental catalyst design and modulation for hydrocarbon pollutants elimination.
Assuntos
Ácidos de Lewis , Oxigênio , Compostos de Cálcio , Metano , Óxidos , TitânioRESUMO
The key molecular events that provoke Parkinson's disease (PD) are not fully understood. Iron deposit was found in the substantia nigra pars compacta (SNpc) of PD patients and animal models, where dopaminergic neurons degeneration occurred selectively. The mechanisms involved in disturbed iron metabolism remain unknown, however, considerable evidence indicates that iron transporters dysregulation, activation of L-type voltage-gated calcium channel (LTCC) and ATP-sensitive potassium (KATP) channels, as well as N-methyl-D-aspartate (NMDA) receptors (NMDARs) contribute to this process. There is emerging evidence on the structural links and functional modulations between iron and α-synuclein, and the key player in PD which aggregates in Lewy bodies. Iron is believed to modulate α-synuclein synthesis, post-translational modification, and aggregation. Furthermore, glia, especially activated astroglia and microglia, are involved in iron deposit in PD. Glial contributions were largely dependent on the factors they released, e.g., neurotrophic factors, pro-inflammatory factors, lactoferrin, and those undetermined. Therefore, iron chelation using iron chelators, the extracts from many natural foods with iron chelating properties, may be an effective therapy for prevention and treatment of the disease.
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Ferro/metabolismo , Doença de Parkinson/fisiopatologia , alfa-Sinucleína/metabolismo , Animais , Canais de Cálcio Tipo L , Neurônios Dopaminérgicos/patologia , Humanos , Canais KATP , Receptores de N-Metil-D-Aspartato , Substância Negra/patologiaRESUMO
Di-(2-ethylhexyl) phthalate (DEHP) is an environmental endocrine disruptor widely employed in plastic bags, industrial paints, cosmetics and food packaging, which has been reported to be harmful to human physical health. Many studies have shown that DEHP causes reproductive system toxicity, but its cytotoxicity to islet cells is few to unknown. In our research, it was found that DEHP could induce apoptosis in INS-1 cells via autophagy and oxidative stress. Taurine, a sulfur-containing ß-amino acid, could reverse DEHP-induced oxidative stress imbalance. Meanwhile, taurine could reduce DEHP-induced excessive autophagy. The interaction between oxidative stress and autophagy has been investigated in this study. After pretreated with autophagy interventional agents, it was found that autophagy was capable of alleviating oxidative stress and ROS production in DEHP-treated INS-1 cells. And down-regulated ROS production by NAC could also turn over uploaded autophagy. Our research provides a perspective about the mechanism of cytotoxicity of DEHP to INS-1 cells and taurine protective effect.
Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Dietilexilftalato/toxicidade , Poluentes Ambientais/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Taurina/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
δ-Tocotrienol, an important component of vitamin E, has been reported to possess some physiological functions, such as anticancer and anti-inflammation, however their molecular mechanisms are not clear. In this study, δ-tocotrienol was isolated and purified from rice bran. The anti-inflammatory effect and mechanism of δ-tocotrienol against lipopolysaccharides (LPS) activated pro-inflammatory mediator expressions in RAW264.7 cells were investigated. Results showed that δ-tocotrienol significantly inhibited LPS-stimulated nitric oxide (NO) and proinflammatory cytokine (TNF-α, IFN-γ, IL-1ß and IL-6) production and blocked the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases 1/2 (ERK1/2). δ-Tocotrienol repressed the transcriptional activations and translocations of nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1), which were closely related with downregulated cytokine expressions. Meanwhile, δ-tocotrienol also affected the PPAR signal pathway and exerted an anti-inflammatory effect. Taken together, our data showed that δ-tocotrienol inhibited inflammation via mitogen-activated protein kinase (MAPK) and peroxisome proliferator-activated receptor (PPAR) signalings in LPS-stimulated macrophages.
Assuntos
Anti-Inflamatórios/farmacologia , Sistema de Sinalização das MAP Quinases , Macrófagos/efeitos dos fármacos , Oryza/química , Vitamina E/análogos & derivados , Animais , Linhagem Celular , Citocinas/metabolismo , Lipopolissacarídeos/toxicidade , MAP Quinase Quinase 4/metabolismo , Macrófagos/metabolismo , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Vitamina E/análise , Vitamina E/farmacologiaRESUMO
Mammalian hibernators experience physiological extremes, e.g. ischemia, muscle disuse and hypothermia, which are lethal to non-hibernators, implying the existence of underlying mechanisms that allow hibernators to withstand these physiological extremes. Increased cell proliferation is suggested to be such a strategy, but its molecular basis remains unknown. In this study, we characterized the expression pattern of ZBED1 (zinc finger, BED-type containing 1), a transcription factor that plays a crucial role in regulating cell proliferation, in five tissues of the greater horseshoe bat (Rhinolophus ferrumequinum) during pre-hibernation, deep hibernation and post-hibernation. Moreover, we investigated the ZBED1 genetic divergence from individuals with variable hibernation phenotypes that cover all three known mtDNA lineages of the species. Expression analyses showed that ZBED1 is overexpressed only in brain and skeletal muscle, not in the other three tissues, suggesting an increased cell proliferation in these two tissues during deep hibernation. Evolutionary analyses showed that ZBED1 sequences were clustered into two well-supported clades with each one dominated by hibernating and non-hibernating individuals, respectively. Positive selection analyses further showed some positively selected sites and a divergent selection pressure among hibernating and non-hibernating groups of R. ferrumequinum. Our results suggest that ZBED1 as a potential candidate gene that regulates cell proliferation for hibernators to face physiological extremes during hibernation.
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Quirópteros/genética , Hibernação/genética , Fatores de Transcrição/metabolismo , Dedos de Zinco , Adaptação Fisiológica/genética , Animais , Encéfalo/metabolismo , Quirópteros/fisiologia , Evolução Molecular , Perfilação da Expressão Gênica , Hibernação/fisiologia , Músculo Esquelético/metabolismo , Fatores de Transcrição/genéticaRESUMO
Bonding area (BA) and bonding strength (BS) interplay dictates tensile strength of a tablet and, hence, tabletability. Using a series of alkali halides with mechanical properties spanning more than one order of magnitude, the role of compaction pressure and mechanical properties on tabletability is systematically investigated and explained using the BA-BS interplay. Results reveal that BA dominates the BA-BS interplay at low pressures, where more plastic powders attain higher tensile strength due to larger BA. In contrast, BS dominates the interplay at high pressures, when difference in BA between powders is minimized. Under the typical compaction pressures of 100-300 MPa, tablet tensile strength is the highest for materials with intermediate hardness, or plasticity, due to an optimal BA-BS interplay.
Assuntos
Dureza , Pós , Pressão , Comprimidos , Resistência à Tração , Comprimidos/química , Pós/química , Cristalização , Composição de Medicamentos/métodos , Excipientes/químicaRESUMO
It is well known that disrupted brain iron homeostasis was involved in Parkinson's disease. We previously reported 6-hydroxydopamine (6-OHDA) could enhance iron influx and attenuate iron efflux process, thus promote iron accumulation in neurons. Astrocytes, the major glial cell type in the central nervous system, are largely responsible for iron distribution in the brain. However, how iron metabolism changes in astrocytes with 6-OHDA treatment are not fully elucidated. In the present study, we first observed that both iron influx and efflux were enhanced with 10 µM 6-OHDA treatment for 24 h in primary cultured astrocytes. In accordance with these iron traffic modulations, both mRNA and protein levels of iron importer divalent metal transporter 1 with iron responsive element (DMT1+IRE) and exporter ferroportin 1 (FPN1) were up-regulated in these cells. L-ferritin mRNA levels were increased. Iron regulatory protein 1 (IRP1) showed a dynamic regulation with 6-OHDA treatment, as indicated by a moderate up-regulation at 12 h, however, down-regulation at 24 h. We further demonstrated that 6-OHDA treatment could induce activation of nuclear factor-kappaB (NF-κB) p65. IκBα activation inhibitor BAY11-7082 fully blocked 6-OHDA induced NF-κB p65 phosphorylation and DMT1 + IRE up-regulation. These results suggest that 6-OHDA might promote iron transport rate in astrocytes by regulating iron transporters, IRP1 expression and NF-κB p65 activation, indicating a different response between neurons and astrocytes.
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Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Transporte Biológico/efeitos dos fármacos , Ferro/metabolismo , Oxidopamina/farmacologia , Animais , Células Cultivadas , Proteína 1 Reguladora do Ferro/metabolismo , Ratos , Ratos Wistar , Fator de Transcrição RelA/metabolismoRESUMO
The transcription factor FoxO1 (forkhead box O1) regulates genes that are involved in development, metabolism, cellular innovation, longevity, and stress responses. Assessment of FoxO1 activity is therefore critical to understand the regulatory network of this transcription factor. FoxO1 transactivation activity relies on its ability to bind to the promoters of target genes, which is controlled by posttranslational modifications (e.g., dephosphorylation or phosphorylation) that may promote nuclear translocation or exclusion of FoxO1. In this chapter we describe the protocols for FoxO1 activity assessment using Western blotting analysis of the posttranslational modification of FoxO1 in whole cell lysates and ELISA of DNA binding activity of FoxO1 in nuclear extracts.
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DNA , Fatores de Transcrição Forkhead , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Fosforilação/fisiologia , Transporte Proteico , DNA/metabolismoRESUMO
Due to its excellent physical properties, γ-TiAl alloy has been widely used in thin-walled components of aerospace engines. However, issues such as low thermal conductivity, poor machinability, and high cutting temperatures often result in difficulties in ensuring the geometric accuracy and surface integrity of the parts. This paper focuses on the study of the thermal deformation behavior of γ-TiAl alloy within a range of higher temperatures and strain rates. Firstly, by conducting quasi-static tests and Hopkinson bar tests on γ-TiAl alloy, the true stress-strain curves of γ-TiAl alloy are obtained within a temperature range of 20~500 °C and a strain rate range of 3000~11,000/s. Based on the Johnson-Cook model, the true stress-strain curves are fitted and analyzed with consideration of the coupling effect of strain rate, temperature, and strain. The strain rate hardening coefficient C and thermal softening exponent m are polynomialized, improving the Johnson-Cook constitutive model of γ-TiAl alloy. The improved model shows significant improvements in the correlation coefficient and absolute errors between the predicted values and experimental values, providing a better reflection of the thermal deformation behavior of γ-TiAl alloy within a range of higher temperatures and strain rates.
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Parkinson's disease (PD) is a progressive neurodegenerative disease with a global burden that affects more often in the elderly. The basal ganglia (BG) is believed to account for movement disorders in PD. More recently, new findings in the original regions in BG involved in motor control, as well as the new circuits or new nucleuses previously not specifically considered were explored. In the present review, we provide up-to-date information related to movement disorders and modulations in PD, especially from the perspectives of brain regions and neuronal circuits. Meanwhile, there are updates in deep brain stimulation (DBS) and other factors for the motor improvement in PD. Comprehensive understandings of brain regions and neuronal circuits involved in motor control could benefit the development of novel therapeutical strategies in PD.
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Estimulação Encefálica Profunda , Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Idoso , Doença de Parkinson/terapia , Encéfalo , Gânglios da BaseRESUMO
Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons in the substantia nigra and leads to progressive motor dysfunction. While studies have focused on the basal ganglia network, recent evidence suggests neuronal systems outside the basal ganglia are also related to PD pathogenesis. The zona incerta (ZI) is a predominantly inhibitory subthalamic region for global behavioral modulation. This study investigates the role of GABAergic neurons in the ZI in a mouse model of 6-hydroxydopamine (6-OHDA)-induced PD. First, we found a decrease in GABA-positive neurons in the ZI, and then the mice used chemogenetic/optogenetic stimulation to activate or inhibit GABAergic neurons. The motor performance of PD mice was significantly improved by chemogenetic/optogenetic activation of GABAergic neurons, and repeated chemogenetic activation of ZI GABAergic neurons increased the dopamine content in the striatum. Our work identifies the role of ZI GABAergic neurons in regulating motor behaviors in 6-OHDA-lesioned PD model mice.
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Autophagy is a major clearance pathway for misfolded α-synuclein which promotes ferroptosis through NCOA4-mediated ferritin degradation. The regulation of these two processes to achieve improved neuroprotection in Parkinson's disease (PD) must be elucidated. Transcription factor EB (TFEB) is a master regulator of both autophagy and lysosome biogenesis, and lysosomes are important cellular iron storage organelles; however, the role of TFEB in ferroptosis and iron metabolism remains unclear. In this study, TFEB overexpression promoted the clearance of misfolded α-synuclein and prevented ferroptosis and iron overload. TFEB overexpression up-regulated transferrin receptor 1 (TfR1) synthesis and increased the localization of TfR1 in the lysosome, facilitating lysosomal iron import and transient lysosomal iron storage. TFEB overexpression increased the levels of cellular iron-safe storage proteins (both ferritin light and heavy chains). These functions in iron metabolism maintain the cellular labile iron at a low level and electrical activity, even under iron overload conditions. Notably, lower levels of cellular labile iron and the upregulation of ferritin light and heavy chains were reversed after TfR1 knockdown in cells overexpressing TFEB, indicating that TFEB regulates cellular labile iron and suppresses ferroptosis in a TfR1 dependent manner. Taken together, this evidence of the regulation of iron metabolism enriches our understanding of the function of TFEB. In addition, TFEB overexpression protects against ferroptosis and iron overload and provides a new direction and perspective for autophagy regulation in PD.
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Ferroptose , Sobrecarga de Ferro , Doença de Parkinson , alfa-Sinucleína/metabolismo , Autofagia/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Ferritinas/metabolismo , Ferroptose/genética , Ferro/metabolismo , Sobrecarga de Ferro/metabolismo , Lisossomos/metabolismo , Doença de Parkinson/metabolismo , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo , Animais , Camundongos , Ratos , Células PC12/metabolismoRESUMO
Adipose plasticity is critical for metabolic homeostasis. Adipocyte transdifferentiation plays an important role in adipose plasticity, but the molecular mechanism of transdifferentiation remains incompletely understood. Here we show that the transcription factor FoxO1 regulates adipose transdifferentiation by mediating Tgfß1 signaling pathway. Tgfß1 treatment induced whitening phenotype in beige adipocytes, reducing UCP1 and mitochondrial capacity and enlarging lipid droplets. Deletion of adipose FoxO1 (adO1KO) dampened Tgfß1 signaling by downregulating Tgfbr2 and Smad3 and induced browning of adipose tissue in mice, increasing UCP1 and mitochondrial content and activating metabolic pathways. Silencing FoxO1 also abolished the whitening effect of Tgfß1 on beige adipocytes. The adO1KO mice exhibited a significantly higher energy expenditure, lower fat mass, and smaller adipocytes than the control mice. The browning phenotype in adO1KO mice was associated with an increased iron content in adipose tissue, concurrent with upregulation of proteins that facilitate iron uptake (DMT1 and TfR1) and iron import into mitochondria (Mfrn1). Analysis of hepatic and serum iron along with hepatic iron-regulatory proteins (ferritin and ferroportin) in the adO1KO mice revealed an adipose tissue-liver crosstalk that meets the increased iron requirement for adipose browning. The FoxO1-Tgfß1 signaling cascade also underlay adipose browning induced by ß3-AR agonist CL316243. Our study provides the first evidence of a FoxO1-Tgfß1 axis in the regulation of adipose browning-whitening transdifferentiation and iron influx, which sheds light on the compromised adipose plasticity in conditions of dysregulated FoxO1 and Tgfß1 signaling.
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Tecido Adiposo Marrom , Transdiferenciação Celular , Camundongos , Animais , Tecido Adiposo Marrom/metabolismo , Ferro/metabolismo , Obesidade/genética , Obesidade/metabolismo , Transdução de Sinais , Tecido Adiposo Branco/metabolismo , Camundongos Endogâmicos C57BL , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismoRESUMO
Tuberculosis causes serious health problem for the world population. Antigenic peptides selected by pathogen-specific cytotoxic T lymphocytes (CTLs) are presented by major histocompatibility complex (MHC; or human leukocyte antigen [HLA] in humans) molecules, and HLA-A restricted responses may be of interest for vaccine development and the understanding of cellular immunity. A series of peptides derived from the 10-KDa culture filtrate protein (CFP10) and the 6 kDa early secretory antigenic target (ESAT-6) in the Mycobacterium tuberculosis (Mtb) have been screened and a CTL epitope restricted by the human leukocyte antigen HLA-A24, a common HLA allele in Asian people, has been identified. In this study, we studied a panel of CFP10 and ESAT-6-derived peptides to identify those with binding motifs for HLA-A24 molecules. The antigenicity of candidate peptides was assessed with in vitro refolding tests and an enzyme-linked immunospot (ELISPOT) assay, and by tetramer staining to determine the capacity to stimulate CTLs from peripheral blood mononuclear cells (PBMCs) of HLA-A24-positive TB Patients. We report that one novel candidate peptide at positions 5-14 of ESAT-6 of Mtb could induce peptide-specific CTLs from PBMCs of HLA-A24-positive patients, but not from HLA-A24-negative patients and HLA-A24-positive healthy controls. Identified epitope is a weak binder for HLA-A24 molecule in a mini MHC refolding assay. Since the peptide is presented by a common HLA class I molecule, it may be useful for immunotherapy against Mtb infection and vaccine development in the large population of Mtb-infected patients.
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Epitopos de Linfócito T/imunologia , Antígeno HLA-A24/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Adolescente , Adulto , Sequência de Aminoácidos , Células Cultivadas , Citocinas/imunologia , Epitopos de Linfócito T/genética , Feminino , Genes MHC Classe I , Antígeno HLA-A24/genética , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Especificidade da Espécie , Tuberculose/genética , Tuberculose/microbiologia , Adulto JovemRESUMO
PURPOSE: To be fully exploitable in both formulation and manufacturing, a drug cocrystal needs to demonstrate simultaneous improvement of multiple key pharmaceutical properties over the pure drug crystal. The present work was aimed at investigating such feasibility with two model profen-nicotinamide cocrystals. METHODS: Phase pure 1:1 ibuprofen-nicotinamide and flurbiprofen-nicotinamide cocrystals were prepared from solutions through rapid solvent removal using rotary evaporation,and characterized by DSC, PXRD, FTIR, phase solubility measurements, equilibrium moisture sorption analysis, dissolution testing and tabletability analysis. RESULTS: Temperature-composition phase diagrams constructed from DSC data for each profen and nicotinamide crystal revealed the characteristic melting point of the 1:1 cocrystal as well as the eutectic temperatures and compositions. Both cocrystals exhibited higher intrinsic dissolution rates than the corresponding profens. The cocrystals also sorbed less moisture and displayed considerably better tabletability than the individual profens and nicotinamide. CONCLUSIONS: Phase behaviors of 1:1 profen-nicotinamide cocrystal systems were delineated by constructing their temperature-composition phase diagrams. Cocrystallization with nicotinamide can simultaneously improve tableting behavior, hygroscopicity, and dissolution performance of ibuprofen and flurbiprofen. This could pave the way for further development of such cocrystal systems into consistent, stable, efficacious and readily manufacturable drug products.