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1.
Neurol Res ; : 1-7, 2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-34979886

RESUMO

Traumatic brain injury (TBI) is the main cause of death and disability among young people. Following TBI, immune system activation and cytokine release induce kinase activity and hyperphosphorylation of tau protein, a structural molecule in axonal microtubules. The cis configuration of phosphorylated tau at Th231 is extremely neurotoxic and is having a prion nature, spreads to brain areas as well as CSF.We examined the cerebrospinal fluid (CSF) cis p-tau levels in 32 TBI patients and 5 non-TBI controls to find out the correlation with TBI severity.   CSF samples were drained 5-7 days after TBI and subjected for ELISA analysis with anti cis p-tau and ß-amyloid antibodies.We had no patients with mild TBI, two patients with moderate (6.2%), 23 patients with severe (71.9%), and 7 patients with critical TBI (21.9%). While mean CSF ß-amyloid in TBI and control groups did not show a statistically significant difference, the mean CSF cis p-tau level was significantly higher in the TBI group than the control samples. Also, intergroup analysis demonstrated that CSF cis p-tau levels were statistically different according to the head injury severity.Although CSF cis p-tau increased in the TBI patients, ß-amyloid did not show a significant difference between patients and controls. Also, we observed an obvious negative correlation between CSF cis p-tau levels and GCS scores. Therefore, future researches on suppression of cis P-tau production or removing previously produced cis P-tau could be a suitable approach in treating TBI in order to prevent tauopathies and future neurodegeneration.

2.
Neurobiol Aging ; 108: 72-79, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34536819

RESUMO

Tauopathies are neurodegenerative diseases that are characterized by pathological accumulation of tau protein. Tau is hyperphosphorylated in the brain of tauopathy patients, and this phosphorylation is proposed to play a role in disease development. However, it has been unclear whether phosphorylation is different among different tauopathies. Here, we investigated the phosphorylation states of tau in several tauopathies, including corticobasal degeneration, Pick's disease, progressive supranuclear palsy (PSP), argyrophilic grain dementia (AGD) and Alzheimer's disease (AD). Analysis of tau phosphorylation profiles using Phos-tag SDS-PAGE revealed distinct phosphorylation of tau in different tauopathies, whereas similar phosphorylation patterns were found within the same tauopathy. For PSP, we found 2 distinct phosphorylation patterns suggesting that PSP may consist of 2 different related diseases. Immunoblotting with anti-phospho-specific antibodies showed different site-specific phosphorylation in the temporal lobes of patients with different tauopathies. AD brains showed increased phosphorylation at Ser202, Thr231 and Ser235, Pick's disease brains showed increased phospho-Ser202, and AGD brains showed increased phospho-Ser396. The cis conformation of the peptide bond between phospho-Thr231 and Pro232 (cis ptau) was increased in AD and AGD. These results indicate that while tau is differently phosphorylated in tauopathies, a similar pathological mechanism may occur in AGD and AD patients. The present data provide useful information regarding tau pathology and diagnosis of tauopathies.

3.
J Neurochem ; 157(3): 727-751, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33264426

RESUMO

Parkinson disease (PD) is the second most common neurodegenerative disorder, whose prevalence is 2~3% in the population over 65. α-Synuclein aggregation is the major pathological hallmark of PD. However, recent studies have demonstrated enhancing evidence of tau pathology in PD. Despite extensive considerations, thus far, the actual spreading mechanism of neurodegeneration has remained elusive in a PD brain. This study aimed to further investigate the development of α-synuclein and tau pathology. We employed various PD models, including cultured neurons treated with either 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or with recombinant α-synuclein. Also, we studied dopaminergic neurons of cytokine Interferon-ß knock-out. Moreover, we examined rats treated with 6-hydroxydopamine, Rhesus monkeys administrated with MPTP neurotoxin, and finally, human post-mortem brains. We found the α-synuclein phosphorylation triggers tau pathogenicity. Also, we observed more widespread phosphorylated tau than α-synuclein with prion-like nature in various brain areas. We optionally removed P-tau or P-α-synuclein from cytokine interferon-ß knock out with respective monoclonal antibodies. We found that tau immunotherapy suppressed neurodegeneration more than α-synuclein elimination. Our findings indicate that the pathogenic tau could be one of the leading causes of comprehensive neurodegeneration triggered by PD. Thus, we can propose an efficient therapeutic target to fight the devastating disorder.


Assuntos
Encéfalo/patologia , Doença de Parkinson/patologia , Tauopatias/patologia , alfa-Sinucleína/genética , Animais , Autopsia , Comportamento Animal , Sobrevivência Celular/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , Feminino , Humanos , Interferon beta/genética , Intoxicação por MPTP/patologia , Macaca mulatta , Masculino , Camundongos , Camundongos Knockout , Doença de Parkinson/psicologia , Gravidez , Ratos , Ratos Wistar , Proteínas Recombinantes , Proteínas tau/biossíntese , Proteínas tau/genética
4.
Cell Mol Neurobiol ; 41(6): 1339-1354, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32696288

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disorder, in which amyloid precursor protein (APP) misprocessing and tau protein hyperphosphorylation are well-established pathogenic cascades. Despite extensive considerations, the central mediator of neuronal cell death upon AD remains under debate. Therefore, we examined the direct interplay between tauopathy and amyloidopathy processes. We employed primary culture neurons and examined pathogenic P-tau and Aß oligomers upon hypoxia treatment by immunofluorescence and immunoblotting. We observed both tauopathy and amyloidopathy processes upon the hypoxia condition. We also applied Aß1-42 or P-tau onto primary cultured neurons. We overexpressed P-tau in SH-SY5Y cells and found Aß accumulation. Furthermore, adult male rats received Aß1-42 or pathogenic P-tau in the dorsal hippocampus and were examined for 8 weeks. Learning and memory performance, as well as anxiety behaviors, were assessed by Morris water maze and elevated plus-maze tests. Both Aß1-42 and pathogenic P-tau significantly induced learning and memory deficits and enhanced anxiety behavior after treatment 2 weeks. Aß administration induced robust tauopathy distribution in the cortex, striatum, and corpus callosum as well as CA1. On the other hand, P-tau treatment developed Aß oligomers in the cortex and CA1 only. Our findings indicate that Aß1-42 and pathogenic P-tau may induce each other and cause almost identical neurotoxicity in a time-dependent manner, while tauopathy seems to be more distributable than amyloidopathy.

5.
Mater Sci Eng C Mater Biol Appl ; 119: 111649, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33321685

RESUMO

The interaction of nanoparticles with protein and cells may provide important information regarding their biomedical implementations. Herein, after synthesis of tin oxide (SnO2) nanoparticles by hydrothermal method, their interaction with human serum albumin (HSA) was evaluated by multispectroscopic and molecular docking (MD) approaches. Furthermore, the selective antiproliferative impact of SnO2 nanoparticles against leukemia K562 cells was assessed by different cellular assays, whereas lymphocytes were used as control cells. TEM, DLS, zeta potential and XRD techniques showed that crystalline SnO2 nanoparticles have a size of less than 50 nm with a good colloidal stability. Fluorescence and CD spectroscopy analysis indicated that the HSA undergoes some slight conformational changes after interaction with SnO2 nanoparticles, whereas the secondary structure of HSA remains intact. Moreover, MD outcomes revealed that the charged residues of HSA preferentially bind to SnO2 nanoclusters in the binding pocket. Antiproliferative examinations displayed that SnO2 nanoparticles can selectively cause the mortality of K562 cells through induction of cell membrane leakage, activation of caspase-9, -8, -3, down regulation of Bcl-2 mRNA, the elevation of ROS level, S phase arrest, and apoptosis. In conclusion, this data may indicate that SnO2 nanoparticles can be used as promising particles to be integrated into therapeutic platforms.


Assuntos
Nanopartículas , Compostos de Estanho , Humanos , Células K562 , Simulação de Acoplamento Molecular
6.
J Biomol Struct Dyn ; 39(8): 3025-3033, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32274964

RESUMO

The widespread antigenic changes lead to the emergence of a new type of coronavirus (CoV) called as severe acute respiratory syndrome (SARS)-CoV-2 that is immunologically different from the previous circulating species. Angiotensin-converting enzyme-2 (ACE-2) is one of the most important receptors on the cell membrane of the host cells (HCs) which its interaction with spike protein (SP) with a furin-cleavage site results in the SARS-CoV-2 invasion. Hence, in this review, we presented an overview on the interaction of ACE-2 and furin with SP. As several kinds of CoVs, from various genera, have at their S1/S2 binding site a preserved site, we further surveyed the role of furin cleavage site (FCS) on the life cycle of the CoV. Furthermore, we discussed that the small molecular inhibitors can limit the interaction of ACE-2 and furin with SP and can be used as potential therapeutic platforms to combat the spreading CoV epidemic. Finally, some ongoing challenges and future prospects for the development of potential drugs to promote targeting specific activities of the CoV were reviewed. In conclusion, this review may pave the way for providing useful information about different compounds involved in improving the effectiveness of CoV vaccine or drugs with minimum toxicity against human health.Communicated by Ramaswamy H. Sarma.


Assuntos
COVID-19 , Furina , Enzima de Conversão de Angiotensina 2 , Angiotensinas , Humanos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus
7.
Mol Neurobiol ; 57(11): 4845-4855, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32808121

RESUMO

Traumatic spinal cord injury (SCI) can result in substantial neurological impairment along with significant emotional and psychological distress. It is clear that there is profound neurodegeneration upon SCI, gradually spread to other spinal cord regions and brain areas. Despite extensive considerations, it remains uncertain how pathogenicity diffuses in the cord. It has been reported that tau protein abnormal hyperphosphorylation plays a central role in neurodegeneration triggered by traumatic brain injury (TBI). Tau is a microtubule-associated protein, heavily implicated in neurodegenerative diseases. Importantly, tau pathology spreads in a traumatic brain in a timely manner. In particular, we have recently demonstrated that phosphorylated tau at Thr231 exists in two distinct cis and trans conformations, in which that cis P-tau is extremely neurotoxic, has a prion nature, and spreads to various brain areas and cerebrospinal fluid (CSF) upon trauma. On the other hand, tau pathology, in particular hyperphosphorylation at Thr231, has been observed upon SCI. Taken these together, we conclude that cis pT231-tau may accumulate and spread in the spinal cord as well as CSF and diffuse tau pathology in the central nervous system (CNS). Moreover, antibody against cis P-tau can target intracellular cis P-tau and protect pathology spreading. Thus, considering cis P-tau as a driver of tau pathology and neurodegeneration upon SCI would open new windows toward understanding the disease development and early biomarkers. Furthermore, it would help us develop effective therapies for SCI patients.


Assuntos
Lesões Encefálicas Traumáticas/patologia , Traumatismos da Medula Espinal/patologia , Proteínas tau/metabolismo , Animais , Lesões Encefálicas Traumáticas/complicações , Modelos Animais de Doenças , Humanos , Degeneração Neural/patologia , Fosforilação , Traumatismos da Medula Espinal/complicações
8.
Int J Nanomedicine ; 15: 4607-4623, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32636621

RESUMO

Aim: The interaction of NPs with biological systems may reveal useful details about their pharmacodynamic, anticancer and antibacterial effects. Methods: Herein, the interaction of as-synthesized Co3O4 NPs with HSA was explored by different kinds of fluorescence and CD spectroscopic methods, as well as molecular docking studies. Also, the anticancer effect of Co3O4 NPs against leukemia K562 cells was investigated by MTT, LDH, caspase, real-time PCR, ROS, cell cycle, and apoptosis assays. Afterwards, the antibacterial effects of Co3O4 NPs against three pathogenic bacteria were disclosed by antibacterial assays. Results: Different characterization methods such as TEM, DLS, zeta potential and XRD studies proved that fabricated Co3O4 NPs by sol-gel method have a diameter of around 50 nm, hydrodynamic radius of 177 nm with a charge distribution of -33.04 mV and a well-defined crystalline phase. Intrinsic, extrinsic, and synchronous fluorescence as well as CD studies, respectively, showed that the HSA undergoes some fluorescence quenching, minor conformational changes, microenvironmental changes as well as no structural changes in the secondary structure, after interaction with Co3O4 NPs. Molecular docking results also verified that the spherical clusters with a dimension of 1.5 nm exhibit the most binding energy with HSA molecules. Anticancer assays demonstrated that Co3O4 NPs can selectively lead to the reduction of K562 cell viability through the cell membrane damage, activation of caspase-9, -8 and -3, elevation of Bax/Bcl-2 mRNA ratio, ROS production, cell cycle arrest, and apoptosis. Finally, antibacterial assays disclosed that Co3O4 NPs can stimulate a promising antibacterial effect against pathogenic bacteria. Conclusion: In general, these observations can provide useful information for the early stages of nanomaterial applications in therapeutic platforms.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Cobalto/química , Cobalto/farmacologia , Nanopartículas Metálicas/química , Óxidos/química , Óxidos/farmacologia , Albumina Sérica Humana/metabolismo , Antibacterianos/química , Antibacterianos/metabolismo , Antineoplásicos/química , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cobalto/metabolismo , Escherichia coli/efeitos dos fármacos , Humanos , Células K562 , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Óxidos/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Albumina Sérica Humana/química , Staphylococcus aureus/efeitos dos fármacos , Difração de Raios X
9.
Ophthalmic Genet ; 41(5): 505-506, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32615840

RESUMO

PURPOSE: Age-related macular degeneration (AMD) as the leading cause of central visual loss in the developed countries has extensive pathologic similarities with Alzheimer's disease (AD). Saitohin rs62063857 Q7 R polymorphism is associated with increased risk of AD though we decided to evaluate the possible association of this polymorphism with advanced AMD. MATERIALS AND METHODS: 152 advanced AMD patients (134 wet AMD and 18 geographic atrophy) and 75 healthy controls included in this study. Cases and controls went through a standard ophthalmologic examination by a retinal specialist. Saitohin gene rs62063857 polymorphism determined by using PCR technique and restriction enzyme HinFI. To evaluate the differences between groups we used t-test, Chi-Squared and one-tailed Fisher exact test. RESULTS: Distribution of genotypes was not significantly different between total AMD or wet AMD patients compared to that of controls (total AMD RR+QR: OR = 1.51, CI = 0.82-2.79, P = .12; wet AMD RR+QR: OR = 1.39, CI = 0.74-2.59, P = .19). The RR+QR genotypes were significantly higher in dry AMD group compared to that of controls (RR+QR: OR = 2.75, CI = 0.96-7.9, P = .05). CONCLUSION: Our results showed that although STH Q7 R polymorphism was not associated with wet AMD susceptibility it was significantly associated with geographic atrophy.


Assuntos
Degeneração Macular/patologia , Polimorfismo de Nucleotídeo Único , Proteínas tau/genética , Idoso , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Degeneração Macular/classificação , Degeneração Macular/genética , Masculino , Prognóstico
10.
Ther Deliv ; 11(6): 387-399, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32578497

RESUMO

Aim: Parkinson's disease (PD) is a neurological disorder resulting from decreased dopamine (DA) secretion in the brain, which reflects impaired motor function. Thus, a drug-delivery system for releasing DA into the brain would be of crucial importance. Materials & methods: We herein examined the in vivo drug efficiency of novel poly-butyl-cyanoacrylate nanoparticles loaded with DA (DA-PBCA NPs). Results & conclusion: The NPs were able to pass through the blood-brain barrier and improve brain structure and function in the PD animal models. Moreover, we found a reduced α-synucleinopathy in the animal model brains after the NPs administration. Thus, the NPs seem to be a reliable DA delivery system for treating PD patients.


Assuntos
Embucrilato , Nanopartículas , Doença de Parkinson , Animais , Encéfalo , Modelos Animais de Doenças , Dopamina/uso terapêutico , Portadores de Fármacos , Embucrilato/uso terapêutico , Humanos , Modelos Animais , Doença de Parkinson/tratamento farmacológico
11.
Stem Cell Res Ther ; 11(1): 203, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460894

RESUMO

BACKGROUND: Retinal and/or optic nerve injury is one of the leading causes of blindness due to retinal ganglion cell (RGC) degeneration. There have been extensive efforts to suppress this neurodegeneration. Various somatic tissue-derived mesenchymal stem cells (MSCs) demonstrated significant neuroprotective and axogenic effects on RGCs. An alternative source of MSCs could be human embryonic stem cells (ES-MSCs), which proliferate faster, express lower levels of inflammatory cytokines, and are capable of immune modulation. It has been demonstrated that MSCs secrete factors or extracellular vesicles that may heal the injury. However, possible therapeutic effects and underlying mechanism of human ES-MSC extracellular vesicles (EVs) on optic nerve injury have not been assessed. METHODS: EVs were isolated from human ES-MSCs. Then, ES-MSC EV was applied to an optic nerve crush (ONC) mouse model. Immunohistofluorescence, retro- and anterograde tracing of RGCs, Western blot, tauopathy in RGCs, and function assessments were performed during 2-month post-treatment to evaluate ONC improvement and underlying mechanism of human ES-MSC EV in in vivo. RESULTS: We found that the ES-MSC EV significantly improved Brn3a+ RGCs survival and retro- and anterograde tracing of RGCs, while preventing retinal nerve fiber layer (RNFL) degenerative thinning compared to the vehicle group. The EVs also significantly promoted GAP43+ axon counts in the optic nerve and improved cognitive visual behavior. Furthermore, cis p-tau, a central mediator of neurodegeneration in the injured RGCs, is detectable after the ONC at the early stages demonstrated tauopathy in RGCs. Notably, after EV treatment cis p-tau was downregulated. CONCLUSIONS: Our findings propose that human ES-MSC EVs, as an off-the-shelf and cell-free product, may have profound clinical implications in treating injured RGCs and degenerative ocular disease. Moreover, the possible mechanisms of human ES-MSC EV are related to the rescue of tauopathy process of RGC degeneration.


Assuntos
Vesículas Extracelulares , Células-Tronco Embrionárias Humanas , Traumatismos do Nervo Óptico , Animais , Modelos Animais de Doenças , Humanos , Traumatismos do Nervo Óptico/terapia , Células Ganglionares da Retina , Roedores
12.
Cell Biochem Funct ; 38(6): 686-694, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32232872

RESUMO

The Wnt pathway is the most important cascade in the nervous system; evidence has indicated that deregulation of the Wnt pathway induced pathogenic hallmarks of neurodegenerative diseases. Glycogen synthase kinase-3ß (GSK-3ß) as the main member of the Wnt pathway increases tau inclusions, the main marker in the neurodegenerative diseases. Phosphorylated tau is observed in the pre-tangle of the neurons in the early stage of neurodegenerative diseases. The researchers always try to improve pharmacological approaches of new therapeutic strategies to the treatment of neurodegenerative diseases that are required to represent a significant entry point by understanding the theoretical interactions of the molecular pathways. In this review, we have discussed the recent knowledge about the canonical and non-canonical Wnt signalling pathway, GSK-3ß, Wnt/ß-catenin antagonists, tau phosphorylation, and their important roles in the neurodegenerative diseases.


Assuntos
Doenças Neurodegenerativas/metabolismo , Via de Sinalização Wnt , Proteínas tau/metabolismo , Animais , Encéfalo/fisiologia , Células Cultivadas , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Ligantes , Neurônios/metabolismo , Fosforilação
13.
J Ophthalmic Vis Res ; 14(4): 491-505, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31875105

RESUMO

Tau is a microtubule-associated protein, which is highly expressed in the central nervous system as well as ocular neurons and stabilizes microtubule structure. It is a phospho-protein being moderately phosphorylated under physiological conditions but its abnormal hyperphosphorylation or some post-phosphorylation modifications would result in a pathogenic condition, microtubule dissociation, and aggregation. The aggregates can induce neuroinflammation and trigger some pathogenic cascades, leading to neurodegeneration. Taking these together, targeting pathogenic tau employing tau immunotherapy may be a promising therapeutic strategy in fighting with cerebral and ocular neurodegenerative disorders.

14.
Int J Nanomedicine ; 14: 6989-7000, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695369

RESUMO

Aim: Among therapeutic proposals for amyloid-associated disorders, special attention has been given to the exploitation of nanoparticles (NPs) as promising agents against aggregation. Methods: In this paper, the inhibitory effect of cerium oxide (CeO2) NPs against α-synuclein (α-syn) amyloid formation was explored by different methods such as Thioflavin T (ThT) and 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence spectroscopy, Congo red adsorption assay, circular dichroism (CD) spectroscopy, transmission electron microscopy (TEM), and bioinformatical approaches. Also, the cytotoxicity of α-syn amyloid either alone or with CeO2 NPs against neuron-like cells (SH-SY5Y) was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, and quantitative real-time polymerase chain reaction (Bax and Bcl-2 gene expression) assays. Results: ThT and ANS fluorescence assays indicated that CeO2 NPs inhibit the formation of aggregated species and hydrophobic patches of α-syn in amyloidogenic conditions, respectively. Congo red and CD assays demonstrated that CeO2 NPs reduce the formation of amyloid species and ß-sheets structures of α-syn molecules, respectively. TEM investigation also confirmed that CeO2 NPs limited the formation of well-defined fibrillary structures of α-syn molecules. Molecular docking and dynamic studies revealed that CeO2 NPs could bind with different affinities to α-syn monomer and amyloid species and fibrillar structure of α-syn is disaggregated in the presence of CeO2 NPs. Moreover, cellular assays depicted that CeO2 NPs mitigate the cell mortality, apoptosis, and the ratio of Bax/Bcl-2 gene expression associated with α-syn amyloids. Conclusion: It may be concluded that CeO2 NPs can be used as therapeutic agents to reduce the aggregation of proteins and mitigate the occurrence of neurodegenerative diseases.


Assuntos
Amiloide/metabolismo , Cério/química , Nanopartículas/química , alfa-Sinucleína/toxicidade , Amiloide/ultraestrutura , Apoptose , Benzotiazóis/metabolismo , Linhagem Celular Tumoral , Vermelho Congo , Humanos , Cinética , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Necrose , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espectrometria de Fluorescência , alfa-Sinucleína/ultraestrutura , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
15.
Int J Pharm ; 572: 118824, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31715345

RESUMO

In this study, we formulated silymarin-HSA nanoplex and assayed its ability to reduce LPS-induced toxicity in vitro and in vivo. Silymarin molecules were encapsulated into HSA nanoplex and the loading efficiency and characterization of fabricated nanoplex were performed by using HPLC, TEM, SEM, DLS, FTIR analysis, and theoretical studies. Afterwards, their protective effect against LPS (20 µg/ml) -induced toxicity in SH-SY5Y cells was investigated by MTT, ROS, and apoptosis assays. For in vivo experiments, rats were pre-treated with either silymarin or silymarin -HSA nanoplex (200 mg/kg) orally for 3 days and at third day received LPS by IP at a dose of 0.5 mg/kg, 150 min before scarification followed by SOD and CAT activity assay. The formulation of silymarin-HSA nanoplex showed a spherical shape with an average diameter between 50 nm and 150 nm, hydrodynamic radius of 188.3 nm, zeta potential of -26.6 mV, and a drug loading of 97.3%. In LPS-treated cells, pretreatments with silymarin-HSA noncomplex recovered the cell viability and decreased the ROS level and corresponding apoptosis more significantly than free silymarin. In rats, it was also depicted that, silymarin-HSA noncomplex can increase the SOD and CAT activity in brain tissue at LPS-triggered oxidative stress model more significantly than the free counterpart. Therefore, nanoformulation of silymarin improved its capability to reduce LPS-induced oxidative stress by restoring cell viability and elevation of SOD and CAT activity in vitro and in vivo, respectively. In conclusion, formulation of silymarin may hold a great promise in the development of antioxidant agents.


Assuntos
Antioxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Albumina Sérica Humana/química , Silimarina/farmacologia , Animais , Antioxidantes/administração & dosagem , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Lipopolissacarídeos/toxicidade , Masculino , Neuroblastoma/patologia , Tamanho da Partícula , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Silimarina/administração & dosagem
16.
Trends Endocrinol Metab ; 30(10): 692-700, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31399291

RESUMO

Several conditions result in neurodegeneration; among which diabetes mellitus (DM) is of crucial importance. Tau (τ) malfunction is a major pathological process participating in neurodegeneration. Despite extensive considerations, the actual causative link between DM and τ abnormalities remains uncertain thus far. Phosphorylated (p)-τ at Thr-Pro motifs can exist in the two distinct cis and trans conformations. cis is neurotoxic, and is accumulated upon various stress conditions, such as nutrition depletion. We assume that pathogenic cis p-τ is the central mediator of neurodegeneration in DM, and propose why different brain areas give various responses to stress conditions. We herein juxtapose recent approaches in diabetic neurodegeneration and propose a therapeutic target to stop neuronal loss during DM.


Assuntos
Diabetes Mellitus/fisiopatologia , Doenças Neurodegenerativas/etiologia , Animais , Diabetes Mellitus/metabolismo , Humanos , Doenças Neurodegenerativas/metabolismo , Fosforilação , Proteínas tau/metabolismo
17.
Int J Nanomedicine ; 14: 5355-5368, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409992

RESUMO

Aim: Nanoparticles (NPs) have been receiving potential interests in protein delivery and cell therapy. As a matter of fact, NPs may be used as great candidates in promoting cell therapy by catalase (CAT) delivery into high oxidative stress tissues. However, for using NPs like SiO2 as carriers, the interaction of NPs with proteins and mesenchymal stem cells (MSCs) should be explored in advance. Methods: In the present study, the interaction of SiO2 NPs with CAT and human MSCs (hMSCs) was explored by various spectroscopic methods (fluorescence, circular dichroism (CD), UV-visible), molecular docking and dynamics studies, and cellular (MTT, cellular morphology, cellular uptake, lactate dehydrogenase, ROS, caspase-3, flow cytometry) assays. Results: Fluorescence study displayed that both dynamic and static quenching mechanisms and hydrophobic interactions are involved in the spontaneous interaction of SiO2 NPs with CAT. CD spectra indicated that native structure of CAT remains stable after interaction with SiO2 NPs. UV-visible study also revealed that the kinetic parameters of CAT such as Km, Vmax, Kcat, and enzyme efficiency were not changed after the addition of SiO2 NPs. Molecular docking and dynamics studies showed that Si and SiO2 clusters interact with hydrophobic residues of CAT and SiO2 cluster causes minor changes in the CAT structure at a total simulation time of 200 ps. Cellular assays depicted that SiO2 NPs induce significant cell mortality, change in cellular morphology, cellular internalization, ROS elevation, and apoptosis in hMSCs at higher concentration than 100 µg/mL (170 µM). Conclusion: The current results suggest that low concentrations of SiO2 NPs induce no substantial change or mortality against CAT and hMSCs, and potentially useful carriers in CAT delivery to hMSC.


Assuntos
Fenômenos Biofísicos , Células-Tronco Mesenquimais/citologia , Modelos Teóricos , Nanopartículas/química , Dióxido de Silício/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Catalase/metabolismo , Forma Celular/efeitos dos fármacos , Dicroísmo Circular , Endocitose/efeitos dos fármacos , Humanos , Cinética , L-Lactato Desidrogenase/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Fluorescência , Termodinâmica
18.
Int J Nanomedicine ; 14: 4637-4648, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31417259

RESUMO

Aim: It has been indicated that NPs may change the amyloidogenic steps of proteins and relevant cytotoxicity. Therefore, this report assigned to explore the impact of ZVFe NPs on the amyloidogenicity and cytotoxicity of α-synuclein as one of the many known amyloid proteins. Methods: The characterization of α-synuclein at amyloidogenic condition either alone or with ZVFe NPs was carried out by fluorescence, CD, UV-visible spectroscopic methods, TEM study, docking, and molecular modeling. The cytotoxicity assay of α-synuclein amyloid in the absence and presence of ZVFe NPs was also done by MTT, LDH, and flow cytometry analysis. Results: ThT fluorescence spectroscopy revealed that ZVFe NPs shorten the lag phase and accelerate the fibrillation rate of α-synuclein. Nile red and intrinsic fluorescence spectroscopy, CD, Congo red adsorption, and TEM studies indicated that ZVFe NP increased the propensity of α-synuclein into the amyloid fibrillation. Molecular docking study revealed that hydrophilic residues, such as Ser-9 and Lys-12 provide proper sites for hydrogen bonding and electrostatic interactions with adsorbed water molecules on ZVFe NPs, respectively. Molecular dynamics study determined that the interacted protein shifted from a natively discorded conformation toward a more packed structure. Cellular assay displayed that the cytotoxicity of α-synuclein amyloid against SH-SY5Y cells in the presence of ZVFe NPs is greater than the results obtained without ZVFe NPs. Conclusion: In conclusion, the existence of ZVFe NPs promotes α-synuclein fibrillation at amyloidogenic conditions by forming a potential template for nucleation, the growth of α-synuclein fibrillation and induced cytotoxicity.


Assuntos
Amiloide/metabolismo , Ferro/química , Nanopartículas Metálicas/química , alfa-Sinucleína/metabolismo , Amiloide/química , Benzotiazóis/química , Morte Celular , Linhagem Celular Tumoral , Vermelho Congo/química , Humanos , Cinética , L-Lactato Desidrogenase/metabolismo , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Oxazinas/química , Agregados Proteicos , Estrutura Secundária de Proteína , Espectrometria de Fluorescência , Tirosina/química , alfa-Sinucleína/química , alfa-Sinucleína/ultraestrutura
19.
Sci Rep ; 9(1): 1558, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30733474

RESUMO

Fibrinogen is one of the key proteins that participate in the protein corona composition of many types of nanoparticles (NPs), and its conformational changes are crucial for activation of immune systems. Recently, we demonstrated that the fibrinogen highly contributed in the protein corona composition at the surface of zeolite nanoparticles. Therefore, understanding the interaction of fibrinogen with zeolite nanoparticles in more details could shed light of their safe applications in medicine. Thus, we probed the molecular interactions between fibrinogen and zeolite nanoparticles using both experimental and simulation approaches. The results indicated that fibrinogen has a strong and thermodynamically favorable interaction with zeolite nanoparticles in a non-cooperative manner. Additionally, fibrinogen experienced a substantial conformational change in the presence of zeolite nanoparticles through a concentration-dependent manner. Simulation results showed that both E- and D-domain of fibrinogen are bound to the EMT zeolite NPs via strong electrostatic interactions, and undergo structural changes leading to exposing normally buried sequences. D-domain has more contribution in this interaction and the C-terminus of γ chain (γ377-394), located in D-domain, showed the highest level of exposure compared to other sequences/residues.


Assuntos
Fenômenos Químicos , Fibrinogênio/química , Modelos Moleculares , Nanopartículas/química , Zeolitas/química , Sítios de Ligação , Humanos , Nanopartículas Metálicas/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Nanopartículas/ultraestrutura , Ligação Proteica , Análise Espectral , Termodinâmica
20.
Int J Nanomedicine ; 14: 257-270, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30643405

RESUMO

Background: Recently, nanomaterials have moved into biological and medicinal implementations like cancer therapy. Therefore, before clinical trials, their binding to plasma proteins like human serum albumin (HSA) and their cytotoxic effects against normal and cancer cell lines should be addressed. Methods: Herein, the interaction of magnesium oxide nanoparticles (MgO NPs) with HSA was studied by means of fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and docking studies. Afterwards, the cytotoxic impacts of MgO NPs on human leukemia cell line (K562) and peripheral blood mononucleated cells (PBMCs) were evaluated by MTT and flow cytometry assays to quantify reactive oxygen species (ROS) generation and apoptosis. Results: It was demonstrated that MgO NPs spontaneously form a static complex with HSA molecules through hydrophobic interactions. Docking study based on the size of NPs demonstrated that different linkages can be established between MgO NPs and HSA. The CD investigation explored that MgO NPs did not alter the secondary structure of HSA. Cellular studies revealed that MgO NPs induced cytotoxicity against K562 cell lines, whereas no adverse effects were detected on PBMCs up to optimum applied concentration of MgO NPs. It was exhibited that ROS production mediated by IC50 concentrations of MgO NPs caused apoptosis-associated cell death. The pre-incubation of K562 with ROS scavenger (curcumin) inhibited the impact of MgO NPs -based apoptosis on cell fate, revealing the upstream effect of ROS in our system. Conclusion: In summary, MgO NPs may exhibit strong plasma distribution and mediate apoptosis by ROS induction in the cancer cell lines. These data demonstrate a safe aspect of MgO NPs on the proteins and normal cells and their application as a distinctive therapeutic approach in the cancer treatment.


Assuntos
Proliferação de Células/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Óxido de Magnésio/química , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Albumina Sérica Humana/metabolismo , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Simulação de Acoplamento Molecular , Conformação Proteica , Albumina Sérica Humana/química , Células Tumorais Cultivadas
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