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INTRODUCTION: The proline-rich decapeptide 10c (Bj-PRO-10c; ENWPHPQIPP) from the Bothrops jararaca snake modulates argininosuccinate synthetase (AsS) activity to stimulate L-arginine metabolite production and neuroprotection in the SH-SY5Y cell line. The relationships between structure, interactions with AsS, and neuroprotection are little known. We evaluated the neuroprotective effects of Bj-PRO-10c and three other PROs (Bn-PRO-10a,
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Introduction. The proline-rich decapeptide 10c (Bj-PRO-10c; ENWPHPQIPP) from the Bothrops jararaca snake modulates argininosuccinate synthetase (AsS) activity to stimulate L-arginine metabolite production and neuroprotection in the SH-SY5Y cell line. The relationships between structure, interactions with AsS, and neuroprotection are little known. We evaluated the neuroprotective effects of Bj-PRO-10c and three other PROs (Bn-PRO-10a, <ENWPRPKIPP; Bn-PRO-10aMK, <ENWPRPKIPPMK; and, Bn-PRO-10c, <ENWPRPKVPP) identified from Bitis nasicornis snake venom, with a high degree of similarity to Bj-PRO-10c, on oxidative stress-induced toxicity in neuronal PC12 cells and L-arginine metabolite generation via AsS activity regulation. Methods. Cell integrity, metabolic activity, reactive oxygen species (ROS) production, and arginase activity were examined after 4 h of PRO pre-treatment and 20 h of H2O2-induced damage. Results. Only Bn-PRO-10a-MK and Bn-PRO-10c restored cell integrity and arginase function under oxidative stress settings, but they did not reduce ROS or cell metabolism. The MK dipeptide in Bn-PRO-10aMK and valine (V8) in Bn-PRO-10c are important to these effects when compared to Bn-PRO-10a. Bj-PRO-10c is not neuroprotective in PC12 cells, perhaps because of their limited NMDA-type glutamate receptor activity. The PROs interaction analysis on AsS activation can be rated as follows: Bj-PRO-10c > Bn-PRO-10c > Bn-PRO-10a-MK > Bn-PRO-10a. The structure of PROs and their correlations with enzyme activity revealed that histidine (H5) and glutamine (Q7) in Bj-PRO-10c potentiated their affinity for AsS. Conclusions. Our investigation provides the first insights into the structure and molecular interactions of PROs with AsS, which could possibly further their neuropharmacological applications.
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Extensive damage to peripheral nerves is a health problem with few therapeutic alternatives. In this context, the development of tissue engineering seeks to obtain materials that can help recreate environments conducive to cellular development and functional repair of peripheral nerves. Different hydrogels have been studied and presented as alternatives for future treatments to emulate the morphological characteristics of nerves. Along with this, other research proposes the need to incorporate electrical stimuli into treatments as agents that promote cell growth and differentiation; however, no precedent correlates the simultaneous effects of the types of hydrogel and electrical stimuli. This research evaluates the neural differentiation of PC12 cells, relating the effect of collagen, alginate, GelMA, and PEGDA hydrogels with electrical stimulation modulated in four different ways. Our results show significant correlations for different cultivation conditions. Electrical stimuli significantly increase neural differentiation for specific experimental conditions dependent on electrical frequency, not voltage. These backgrounds allow new material treatment schemes to be formulated through electrical stimulation in peripheral nerve tissue engineering.
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Artepillin C is the most studied compound in Brazilian Green Propolis and, along with its acetylated derivative, displays neurotrophic activity on PC12â cells. Specific inhibitors of the trkA receptor (K252a), PI3K/Akt (LY294002), and MAPK/ERK (U0126) signaling pathways were used to investigate the neurotrophic mechanism. The expression of proteins involved in axonal and synaptic plasticity (GAP-43 and Synapsinâ I) was assessed by western blotting. Additionally, physicochemical properties, pharmacokinetics, and drug-likeness were evaluated by the SwissADME web tool. Both compounds induced neurite outgrowth by activating the NGF-signaling pathways but through different neuronal proteins. Furthermore, inâ silico analyses showed interesting physicochemical and pharmacokinetic properties of these compounds. Therefore, these compounds could play an important role in axonal and synaptic plasticity and should be further investigated.
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Própolis , Ratas , Animales , Células PC12 , Própolis/farmacología , Própolis/metabolismo , Neuritas/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Brasil , Transducción de Señal , Proyección NeuronalRESUMEN
Resumen Los feocromocitomas y paragangliomas son neoplasias neuroendocrinas infrecuentes que pueden producir catecolaminas. Tienen una incidencia menor a un caso por millón de habitantes. Son histológicamente benignas y muestran mínimas diferencias respecto a sus contrapartes malignas. Asimismo, son dos de las neoplasias humanas con mayor carga genética. La mutación más común es en la vía del complejo de la succinato deshidrogenasa (SDH) y, de esta, una de las que menos se reportan son las variantes de la SDH subunidad A (SDHA). Se describe el caso de un paciente con feocromocitoma y paraganglioma asociados a una mutación en SDHA y se señala su comportamiento y buena respuesta clínica al manejo quirúrgico y vigilancia activa.
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Doxycycline (DOX) is a widely used antibiotic that is able to cross the blood-brain barrier. Several studies have shown its neuroprotective effect against neurodegeneration and have associated it with antioxidant, anti-apoptotic, and anti-inflammatory mechanisms. We have recently demonstrated that DOX mimics nerve growth factor (NGF) signaling in PC12 cells. However, the involvement of this mechanism in the neuroprotective effect of DOX is unknown. Axonal degeneration and synaptic loss are key events at the early stages of neurodegeneration, and precede the neuronal death in neurodegenerative diseases, including Parkinson's disease (PD). Therefore, the regeneration of the axonal and synaptic network might be beneficial in PD. The effect of DOX in PC12 cells treated with the Parkinsonian neurotoxin 1-methyl-4-phenylpyridinium (MPP+) was addressed. Doxycycline reduced the inhibition of neuritogenesis induced by MPP+, even in cells deprived of NGF. The mechanism involved the upregulation of GAP-43, synapsin I, ß-III-tubulin, F-actin, and neurofilament-200, proteins that are associated with axonal and synaptic plasticity. Considering the role of axonal degeneration and synaptic loss at the initial stages of PD, the recent advances in early diagnosis of neurodegeneration, and the advantages of drug repurposing, doxycycline is a promising candidate to treat PD.
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Fármacos Neuroprotectores , Enfermedad de Parkinson , Ratas , Animales , Humanos , Regulación hacia Arriba , Doxiciclina/farmacología , Doxiciclina/uso terapéutico , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Factor de Crecimiento Nervioso/metabolismo , Factor de Crecimiento Nervioso/uso terapéutico , Proteínas/metabolismo , Enfermedad de Parkinson/tratamiento farmacológico , Células PC12 , Tubulina (Proteína)/metabolismo , 1-Metil-4-fenilpiridinio/toxicidad , 1-Metil-4-fenilpiridinio/uso terapéuticoRESUMEN
Parkinson's disease (PD) is characterized by dopaminergic cell loss in the substantia nigra, and PD brains show neuroinflammation, oxidative stress, and mitochondrial dysfunction. The study evaluated the neuroprotective activity of 1α,25-dihydroxy vitamin D3 (VD3), on the rotenone (ROT)-induced cytotoxicity in PC12 cells. The viability parameters were assessed by the MTT and flow cytometry, on cells treated or not with VD3 and/or ROT. Besides, ROS production, cell death, mitochondrial transmembrane potential, reduced GSH, superoxide accumulation, molecular docking (TH and Keap1-Nrf2), and TH, Nrf2, NF-kB, and VD3 receptor protein contents by western blot were evaluated. VD3 was shown to improve the viability of ROT-exposed cells. Cells exposed to ROT showed increased production of ROS and superoxide, which decreased after VD3. ROT decrease in the mitochondrial transmembrane potential was prevented, after VD3 treatment and, VD3 was shown to interact with tyrosine hydroxylase (TH) and Nrf2. While ROT decreased TH, Nrf2, and NF-kB expressions, these effects were reversed by VD3. In addition, VD3 also increased VD3 receptor protein contents and values went back to those of controls after ROT exposure. VD3 protects PC12 cells against ROT damage, by decreasing oxidative stress and improving mitochondrial function. One target seems to be the TH molecule and possibly an indirect Nrf2 activation could also justify its neuroprotective actions on this PC12 cell model of PD.
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Fármacos Neuroprotectores , Enfermedad de Parkinson , Ratas , Animales , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Rotenona/toxicidad , Células PC12 , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Especies Reactivas de Oxígeno/metabolismo , FN-kappa B/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Superóxidos/metabolismo , Simulación del Acoplamiento Molecular , Fármacos Neuroprotectores/farmacología , Estrés OxidativoRESUMEN
Chromaffin granules isolated from adrenal glands constitute a powerful experimental tool to the study of secretory vesicle components and their participation in fusion and docking processes, vesicle aggregation, and interactions with cytosolic components. Although it is possible to isolate and purify chromaffin granules from adrenal glands of different species, bovine adrenal glands are the most used tissue source due to its easy handling and the large amount of granules that can be obtained from this tissue. In this chapter, we describe an easy-to-use and short-term protocol for efficiently obtaining highly purified chromaffin granules from bovine adrenal medulla. We additionally include protocols to isolate granules from cultured bovine chromaffin cells and PC12 cells, as well as a section to obtain chromaffin granules from mouse adrenal glands.
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Médula Suprarrenal , Células Cromafines , Células Neuroendocrinas , Glándulas Suprarrenales , Animales , Bovinos , Gránulos Cromafines , Ratones , Células PC12 , RatasRESUMEN
Major histocompatibility complex class I (MHC-I) has been implicated in several types of neuroplasticity phenomena. Interferon beta-1b (IFN-ß) increases MHC-I expression by motoneurons after sciatic nerve crush in mice, improving axonal growth and functional recovery. Additionally, IFN-ß induces glial hypertrophy associated with upregulation of glial fibrillary acidic protein (GFAP) and MHC-I in murine astrocytes in vitro. As knowledge about MHC-I and its role in synaptic plasticity in human astrocytes (HAs) is scarce, we investigated these aspects in mature HAs obtained from the neocortex of patients undergoing surgery due to hippocampal sclerosis. Cells were exposed to media in the absence (0 IU/ml) or presence of IFN-ß for 5 days (500 IU/ml). Beta-2 microglobulin (ß2m), a component of the MHC-I, GFAP and vimentin proteins, was quantified by flow cytometry (FC) and increased by 100%, 60% and 46%, respectively, after IFN-ß exposure. We also performed qRT-PCR gene expression analyses for ß2m, GFAP, vimentin, and pro- and anti-inflammatory cytokines. Our data showed that IFN-ß-treated astrocytes displayed ß2m and GFAP gene upregulation. Additionally, they presented a proinflammatory profile with increase in the IL-6 and IL-1ß genes and a tendency to upregulate TNF-α. Moreover, we evaluated the effect of HAs conditioned medium (CM) on the formation/maintenance of neurites/synapses by the PC12 lineage. Synaptophysin protein expression was quantified by FC. The CM of IFN-ß-activated astrocytes was not harmful to PC12 neurites, and there was no change in synaptophysin protein expression. Therefore, IFN-ß activated HAs by increasing GFAP, vimentin and MHC-I protein expression. Like MHC-I modulation and astrocyte activation may be protective after peripheral nerve damage and in some neurodegenerative conditions, this study opens perspectives on the pathophysiological roles of astroglial MHC-I in the human CNS.
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Astrocitos , Interferón beta , Humanos , Animales , Ratones , Astrocitos/metabolismo , Sinaptofisina/genética , Sinaptofisina/metabolismo , Sinaptofisina/farmacología , Vimentina/genética , Vimentina/metabolismo , Vimentina/farmacología , Interferón beta/genética , Interferón beta/metabolismo , Interferón beta/farmacología , Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/metabolismo , Complejo Mayor de Histocompatibilidad , FenotipoRESUMEN
The shortest dystrophins, Dp71 and Dp40, are transcribed from the DMD gene through an internal promoter located in intron 62. These proteins are the main product of the DMD gene in the nervous system and have been involved in various functions related to cellular differentiation and proliferation as well as other cellular processes. Dp71 mRNA undergoes alternative splicing that results in different Dp71 protein isoforms. The subcellular localization of some of these isoforms in the PC12 cell line has been previously reported, and a differential subcellular distribution was observed, which suggests a particular role for each isoform. With the aim of obtaining information on their function, this study identified factors involved in the nuclear transport of Dp71 and Dp40 isoforms in the PC12 cell line. Cell cultures were treated with specific nuclear import/export inhibitors to determine the Dp71 isoform transport routes. The results showed that all isoforms of Dp71 and Dp40 included in the analysis have the ability to enter the cell nucleus through α/ß importin, and the main route of nuclear export for Dp71 isoforms is through the exportin CRM1, which is not the case for Dp40.
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Distrofina , beta Carioferinas , Transporte Activo de Núcleo Celular , Animales , Distrofina/genética , Distrofina/metabolismo , Espacio Intracelular , Carioferinas/metabolismo , Células PC12 , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ARN Mensajero/metabolismo , Ratas , beta Carioferinas/metabolismoRESUMEN
Calafate is a berry rich in anthocyanins that presents higher content of polyphenols than other fruits. Its compounds have been described previously, however, the potential thereof in preventing and treating degenerative disorders has not yet been studied. Due to its astringency, the consumption of this berry in its natural state is limited. To profit from the aforementioned properties and reduce palatability issues, calafate berry extracts were microencapsulated by spray drying, a rapid, cost-effective and scalable process, and were then compared with freeze drying as a control. The stability of its contents and its in-vitro potential, with respect to AChE activity and neuroprotection, were measured from the obtained microcapsules, resulting from temperature treatments and different encapsulant contents. The results indicated that the spray-dried powders were stable, despite high temperatures, and their encapsulation exhibited nearly 50% efficiency. The highest quantity of polyphenols and 3-O-glycosylated anthocyanins was obtained from encapsulation with 20% maltodextrin, at 120 °C. Temperature did not affect the microcapsules' biological action, as demonstrated by their antioxidant activities. The prevention of Aß peptide cytotoxicity in PC12 cells (20%) revealed that encapsulated calafate can confer neuroprotection. We conclude that spray-drying is an appropriate technique for scaling-up and producing new value-added calafate formulations with anti-neurodegenerative effects and vivid colors.
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Doxycycline has been used as antibiotic since the 1960s. Recently, studies have shown that doxycycline is neuroprotective in models of neurodegenerative diseases and brain injuries, mainly due to anti-inflammatory and anti-apoptotic effects. However, it is not known if doxycycline has neurotrophic potential, which is relevant, considering the role of axonal degeneration at the early stages of neurodegeneration in Alzheimer's disease, Amyotrophic Lateral Sclerosis and Parkinson's disease as well as in normal aging. Axons are preceded by the formation of neurites, the hallmark of the neuronal differentiation induced by neurotrophins like NGF. Therefore, the modulation of neurotrophin receptors aimed at formation and regeneration of axons has been proposed as a strategy to delay the progression of neurodegeneration and has gained relevance as new techniques for early diagnosis arise. Based on these premises, we investigated the potential of doxycycline to mimic the effects of Nerve Growth Factor (NGF) with focus on the signaling pathways and neuronal modulators of neurite initiation, growth and branching. We used PC12 cells, a neuronal model widely employed to study the neurotrophic pathways and mechanisms induced by NGF. Results showed that doxycycline induced neurite outgrowth via activation of the trkA receptor and the downstream signaling pathways, PI3K/Akt and MAPK/ERK, without inducing the expression of NGF. Doxycycline also increased the expression of GAP-43, synapsin I and NF200, proteins involved in axonal and synaptic plasticity. Altogether, these data demonstrate, for the first time, the neurotrophic potential of doxycycline, which might be useful to restore the neuronal connectivity lost at the initial phase of neurodegeneration.
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Antibacterianos/farmacología , Doxiciclina/farmacología , Factor de Crecimiento Nervioso/metabolismo , Animales , Carbazoles/farmacología , Supervivencia Celular/efectos de los fármacos , Proteína GAP-43/metabolismo , Alcaloides Indólicos/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Factor de Crecimiento Nervioso/farmacología , Proteínas de Neurofilamentos/metabolismo , Proyección Neuronal/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Células PC12 , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Receptor trkA/antagonistas & inhibidores , Receptor trkA/metabolismo , Transducción de Señal/efectos de los fármacos , Sinapsinas/metabolismoRESUMEN
B-N-methylamino-L-alanine (BMAA), a cyanotoxin produced by most cyanobacteria, has been proposed to cause long term damages leading to neurodegenerative diseases, including Amyotrophic Lateral Sclerosis/Parkinsonism Dementia complex (ALS/PDC) and retinal pathologies. Previous work has shown diverse mechanisms leading to BMAA-induced degeneration; however, the underlying mechanisms of toxicity affecting retina cells are not fully elucidated. We here show that BMAA treatment of rat retina neurons in vitro induced nuclear fragmentation and cell death in both photoreceptors (PHRs) and amacrine neurons, provoking mitochondrial membrane depolarization. Pretreatment with the N-Methyl-D-aspartate (NMDA) receptor antagonist MK-801 prevented BMAA-induced death of amacrine neurons, but not that of PHRs, implying activation of NMDA receptors participated only in amacrine cell death. Noteworthy, BMAA stimulated a selective axonal outgrowth in amacrine neurons, simultaneously promoting growth cone destabilization. BMAA partially decreased the viability of Müller glial cells (MGC), the main glial cell type in the retina, induced marked alterations in their actin cytoskeleton and impaired their capacity to protect retinal neurons. BMAA also induced cell death and promoted axonal outgrowth in differentiated rat pheochromocytoma (PC12) cells, implying these effects were not limited to amacrine neurons. These results suggest that BMAA is toxic for retina neurons and MGC and point to the involvement of NMDA receptors in amacrine cell death, providing new insight into the mechanisms involved in BMAA neurotoxic effects in the retina.
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Aminoácidos Diaminos/toxicidad , Células Ependimogliales/efectos de los fármacos , Agonistas de Aminoácidos Excitadores/toxicidad , Enfermedades de la Retina/inducido químicamente , Neuronas Retinianas/efectos de los fármacos , Animales , Animales Recién Nacidos , Supervivencia Celular/efectos de los fármacos , Toxinas de Cianobacterias , Fragmentación del ADN/efectos de los fármacos , Maleato de Dizocilpina/farmacología , Células Ependimogliales/patología , Antagonistas de Aminoácidos Excitadores/farmacología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Enfermedades de la Retina/metabolismo , Enfermedades de la Retina/prevención & control , Neuronas Retinianas/patologíaRESUMEN
The Dp71 protein is the most abundant dystrophin in the central nervous system (CNS). Several dystrophin Dp71 isoforms have been described and are classified into three groups, each with a different C-terminal end. However, the functions of Dp71 isoforms remain unknown. In the present study, we analysed the effect of Dp71eΔ71 overexpression on neuronal differentiation of PC12 Tet-On cells. Overexpression of dystrophin Dp71eΔ71 stimulates neuronal differentiation, increasing the percentage of cells with neurites and neurite length. According to 2-DE analysis, Dp71eΔ71 overexpression modified the protein expression profile of rat pheochromocytoma PC12 Tet-On cells that had been treated with neuronal growth factor (NGF) for nine days. Interestingly, all differentially expressed proteins were up-regulated compared to the control. The proteomic analysis showed that Dp71eΔ71 increases the expression of proteins with important roles in the differentiation process, such as HspB1, S100A6, and K8 proteins involved in the cytoskeletal structure and HCNP protein involved in neurotransmitter synthesis. The expression of neuronal marker TH was also up-regulated. Mass spectrometry data are available via ProteomeXchange with identifier PXD009114. SIGNIFICANCE: This study is the first to explore the role of the specific isoform Dp71eΔ71. The results obtained here support the hypothesis that the dystrophin Dp71eΔ71 isoform has an important role in the neurite outgrowth by regulating the levels of proteins involved in the cytoskeletal structure, such as HspB1, S100A6, and K8, and in neurotransmitter synthesis, such as HCNP and TH, biological processes required to stimulate neuronal differentiation.
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Diferenciación Celular , Distrofina/fisiología , Proyección Neuronal , Neuronas/citología , Animales , Proteínas del Citoesqueleto/metabolismo , Distrofina/farmacología , Neurotransmisores/biosíntesis , Células PC12 , Isoformas de Proteínas , Proteómica/métodos , RatasRESUMEN
AIM: Scaffolds are a promising approach for spinal cord injury (SCI) treatment. FGF-2 is involved in tissue repair but is easily degradable and presents collateral effects in systemic administration. In order to address the stability issue and avoid the systemic effects, FGF-2 was encapsulated into core-shell microfibers by coaxial electrospinning and its in vitro and in vivo potential were studied. Materials & methods: The fibers were characterized by physicochemical and biological parameters. The scaffolds were implanted in a hemisection SCI rat model. Locomotor test was performed weekly for 6 weeks. After this time, histological analyses were performed and expression of nestin and GFAP was quantified by flow cytometry. Results: Electrospinning resulted in uniform microfibers with a core-shell structure, with a sustained liberation of FGF-2 from the fibers. The fibers supported PC12 cells adhesion and proliferation. Implanted scaffolds into SCI promoted locomotor recovery at 28 days after injury and reduced GFAP expression. CONCLUSION: These results indicate the potential of these microfibers in SCI tissue engineering. [Formula: see text].
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Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Médula Espinal/patología , Ingeniería de Tejidos/métodos , Andamios del Tejido , Animales , Ensayo de Materiales , Células PC12 , Ratas , Médula Espinal/metabolismo , Médula Espinal/ultraestructura , Traumatismos de la Médula Espinal/terapiaRESUMEN
ABSTRACT This study is to investigate the most efficient extractives of extracting oil recipe for stroke treatment and the protective effects on an oxygen and glucose deprivation model in PC12 cells. An orthogonal experimental design L9 (34) was carried out for oil recipe's optimization with supercritical CO2 fluid extraction. 2-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and enzyme-linked immunosorbent assay were conducted to evaluate cell activity and indexes in the cell lysate. The result showed that the optimum extraction condition was 30 Mpa, 50 ºC, 100 min, the extracts were analyzed by gas chromatography-mass spectrometry and among forty detected compounds 27 were identified, representing 80.86% of the total oil content. trans-Cinnamaldehyde (14.14%), piperine (9.32%), β-amyrin (6.79%), lupenone (6.28%), longifolene (6.07%), β-caryophyllene (5.21%), α-bisabolol (4.11%), and β-bisabolene (2.56%) were high mass fraction. Oil recipe could significantly attenuate PC12 cell damage, the lactate dehydrogenase release and decreased the malondialdehyde levels, glutathione peroxidase and nicotinamide adenine dinucleotide phosphate oxidase activity, glutathione and nitric oxide content (p < 0.01) and increased the level of superoxide dismutase after oxygen and glucose deprivation. The protective mechanism may be related to oil recipe's antioxidant effect by scavenging free radicals.
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Thallium (Tl) is a toxic heavy metal that causes oxidative stress both in vitro and in vivo. In this work, we evaluated the production of oxygen (ROS)- and nitrogen (RNS)-reactive species in adherent PC12 (PC12adh) cells exposed for 0.5-6 h to Tl(I) or Tl(III) (10-100 µM). In this system, Tl(I) induced mostly H2O2 generation while Tl(III) induced H2O2 and ONOO·- generation. Both cations enhanced iNOS expression and activity, and decreased CuZnSOD expression but without affecting its activity. Tl(I) increased MnSOD expression and activity but Tl(III) decreased them. NADPH oxidase (NOX) activity remained unaffected throughout the period assessed. Oxidant levels returned to baseline values after 6 h of incubation, suggesting a response of the antioxidant defense system to the oxidative insult imposed by the cations. Tl also affected the glutathione-dependent system: while Tl(III) increased glutathione peroxidase (GPx) expression and activity, Tl(I) and Tl(III) decreased glutathione reductase (GR) expression. However, GR activity was mildly enhanced by Tl(III). Finally, thioredoxin-dependent system was evaluated. Only Tl(I) increased 2-Cys peroxiredoxins (2-Cys Prx) expression, although both cations increased their activity. Tl(I) increased cytosolic thioredoxin reductase (TrxR1) and decreased mitochondrial (TrxR2) expression. Tl(III) had a biphasic effect on TrxR1 expression and slightly increased TrxR2 expression. Despite of this, both cations increased total TrxR activity. Obtained results suggest that in Tl(I)-exposed PC12adh cells, there is an early response to oxidative stress mainly by GSH-dependent system while in Tl(III)-treated cells both GSH- and Trx-dependent systems are involved.
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Antioxidantes/metabolismo , Glutatión/metabolismo , Estrés Oxidativo/efectos de los fármacos , Talio/toxicidad , Tiorredoxinas/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Enzimas/metabolismo , Inactivación Metabólica/efectos de los fármacos , Estrés Oxidativo/fisiología , Células PC12 , Ratas , Especies Reactivas de Oxígeno/metabolismo , Talio/administración & dosificación , Talio/química , Pruebas de Toxicidad/métodosRESUMEN
Advances in the generation of suitable thermosensitive hydrogels for the delivery of cells in neural tissue engineering demonstrate a delicate relationship between physical properties and capabilities to promote cell proliferation and differentiation. To improve the properties of these materials, it is possible to add liposomes for the controlled release of bioactive elements, which in turn can affect the physical and biological properties of the hydrogels. In the present investigation, different hydrogels based on Pluronic F127 have been formulated with the incorporation of chitosan and two types of liposomes of two different sizes. The rheological and thermal properties and their relation with the neurite proliferation and growth of the PC12 cell line were evaluated. Our results show that the incorporation of liposomes modifies the properties of the hydrogels dependent on the concentration of chitosan and the lipid type in the liposomes, which directly affect the capabilities of the hydrogels to promote the viability and differentiation of PC12 cells.
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ABSTRACT Amburana cearensis (Allemão) A.C. Sm., Fabaceae, has been widely studied for its medicinal activities. Many neurodegenerative disorders are caused by oxidative stress, mitochondrial dysfunction, excitotoxicity induced by glutamate and ultimately cell death. This study describes the chemical profile of the ethanolic, hexane, dichloromethane, and ethyl acetate extracts obtained from seeds of A. cearensis. The objective of this study was to investigate the chemical profile of extracts obtained from seeds of A. cearensis, as well as their cytotoxicity and neuroprotective effects in cultures of neural PC12 cells. Metabolite profile was performed by GC–MS. PC12 cells were treated with increasing concentrations of the extracts (0.01–2000 µg/ml) and the cell viability was analyzed after 24 and 72 h using an MTT test. For the excitotoxicity assay, PC12 cells were pre-treated with glutamate (1 mM) for 6 h and treated with increasing concentrations (0.1–1000 µg/ml) of the extracts. The chromatographic analysis of the extracts detected various compounds with antioxidant properties, with the majority of peaks corresponding to the isoflavone coumarin. Only the hexane extract showed toxicity after 72 h exposure at the highest concentration (1000 µg/ml). By contrast, all extracts increased the cellular viability of PC12 cells against the toxicity caused by glutamate. Therefore, the extracts from the seeds of A. cearensis showed no toxicity and have neuroprotective potential against neuronal damage induced by glutamate, which may be related to their antioxidant properties.
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2-Aminothiazolines share an isosteric relationship with imidazolines and oxazolines with antihypertensive activity mainly mediated by the imidazoline I1-receptor. In the present work, we have prepared five aminothiazolines, following a previously described synthetic pathway. Aminothiazolines derived from dicyclopropylmethylamine (ATZ1) and cyclohexylamine (3) are unprecedented in the literature. Competitive radioligand assay was carried out with all synthetic compounds, and the I1 receptor affinity in comparison to rilmenidine in PC12 cells was determined. Surprisingly, the rilmenidine isoster (ATZ1) showed no I1-receptor interaction. Diethyl (ATZ4) and 2-ethyl-hexylamine (ATZ5) derivatives bind to the receptor with 11.98 and 10.94nmol/l, respectively. These compounds were selected for in vivo experiments. Both compounds reduced the blood pressure of spontaneously hypertensive rats (SHR). The hypotensive effect of these compounds was abrogated in the presence of α2 adrenergic (yohimbine) and I1 (efaroxan) receptor antagonists suggesting that both aminothiazolines bind to the adrenergic and imidazoline receptors. Lipinski's descriptors of the synthesized aminothiazolines were calculated and are similar to the known imidazoline I1 receptor ligands. 3D-Similarity between ATZ5 and agmatine, the natural imidazoline receptor ligand, was also observed.