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1.
Biochemistry ; 60(47): 3644-3658, 2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34730940

RESUMO

The aggregation of α-synuclein (αSN) and increased oxidative stress leading to lipid peroxidation are pathological characteristics of Parkinson's disease (PD). Here, we report that aggregation of αSN in the presence of lipid peroxidation products 4-hydroxy-2-nonenal (HNE) and 4-oxo-2-nonenal (ONE) increases the stability and the yield of αSN oligomers (αSO). Further, we show that ONE is more efficient than HNE at inducing αSO. In addition, we demonstrate that the two αSO differ in both size and shape. ONE-αSO are smaller in size than HNE-αSO, except when they are formed at a high molar excess of aldehyde. In both monomeric and oligomeric αSN, His50 is the main target of HNE modification, and HNE-induced oligomerization is severely retarded in the mutant His50Ala αSN. In contrast, ONE-induced aggregation of His50Ala αSN occurs readily, demonstrating the different pathways for inducing αSN aggregation by HNE and ONE. Our results show different morphologies of the HNE-treated and ONE-treated αSO and different roles of His50 in their modification of αSN, but we also observe structural similarities between these αSO and the non-treated αSO, e.g., flexible C-terminus, a folded core composed of the N-terminal and NAC region. Furthermore, HNE-αSO show a similar deuterium uptake as a previously characterized oligomer formed by non-treated αSO, suggesting that the backbone conformational dynamics of their folded cores resemble one another.


Assuntos
Aldeídos/metabolismo , Doença de Parkinson/patologia , alfa-Sinucleína/metabolismo , Aldeídos/química , Linhagem Celular Tumoral , Humanos , Peroxidação de Lipídeos , Ressonância Magnética Nuclear Biomolecular , Agregados Proteicos , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Espalhamento a Baixo Ângulo , Difração de Raios X , alfa-Sinucleína/química , alfa-Sinucleína/isolamento & purificação , alfa-Sinucleína/ultraestrutura
2.
Materials (Basel) ; 14(20)2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34683572

RESUMO

Development of nanocarrier-based drug delivery systems is a major breakthrough in pharmacology, promising targeted delivery and reduction in drug toxicity. On the cellular level, encapsulation of a drug substantially affects the endocytic processes due to nanocarrier-membrane interaction. In this study we synthesized and characterized nanocarriers assembled from amphiphilic oligomers of N-vinyl-2-pyrrolidone with a terminal thiooctadecyl group (PVP-OD). It was found that the dissolution free energy of PVP-OD depends linearly on the molecular mass of its hydrophilic part up to M¯n = 2 × 104, leading to an exponential dependence of critical aggregation concentration (CAC) on the molar mass. A model hydrophobic compound (DiI dye) was loaded into the nanocarriers and exhibited slow release into the aqueous phase on a scale of 18 h. Cellular uptake of the loaded nanocarriers and that of free DiI were compared in vitro using glioblastoma (U87) and fibroblast (CRL2429) cells. While the uptake of both DiI/PVP-OD nanocarriers and free DiI was inhibited by dynasore, indicating a dynamin-dependent endocytic pathway as a major mechanism, a decrease in the uptake rate of free DiI was observed in the presence of wortmannin. This suggests that while macropinocytosis plays a role in the uptake of low-molecular components, this pathway might be circumvented by incorporation of DiI into nanocarriers.

3.
PLoS One ; 16(7): e0253613, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34288927

RESUMO

Small cell lung cancer (SCLC) patients have augmented risk of developing venous thromboembolism, but the mechanisms triggering this burden on the coagulation system remain to be understood. Recently, cell-derived microparticles carrying procoagulant phospholipids (PPL) and tissue factor (TF) in their membrane have attracted attention as possible contributors to the thrombogenic processes in cancers. The aims of this study were to assess the coagulation activity of platelet-poor plasma from 38 SCLC patients and to provide a detailed procoagulant profiling of small and large extracellular vesicles (EVs) isolated from these patients at the time of diagnosis, during and after treatment compared to 20 healthy controls. Hypercoagulability testing was performed by thrombin generation (TG), procoagulant phospholipid (PPL), TF activity, Protein C, FVIII activity and cell-free deoxyribonucleic acid (cfDNA), a surrogate measure for neutrophil extracellular traps (NETs). Our results revealed a coagulation activity that is significantly increased in the plasma of SCLC patients when compared to age-related healthy controls, but no substantial changes in coagulation activity during treatment and at follow-up. Although EVs in the patients revealed an increased PPL and TF activity compared with the controls, the TG profiles of EVs added to a standard plasma were similar for patients and controls. Finally, we found no differences in the coagulation profile of patients who developed VTE to those who did not, i.e. the tests could not predict VTE. In conclusion, we found that SCLC patients display an overall increased coagulation activity at time of diagnosis and during the disease, which may contribute to their higher risk of VTE.


Assuntos
Carcinoma de Células Pequenas/sangue , Cisteína Endopeptidases/sangue , Neoplasias Pulmonares/sangue , Proteínas de Neoplasias/sangue , Trombofilia/sangue , Tromboplastina/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Testes de Coagulação Sanguínea , Carcinoma de Células Pequenas/etiologia , Carcinoma de Células Pequenas/patologia , Centrifugação , DNA/sangue , Vesículas Extracelulares/química , Vesículas Extracelulares/ultraestrutura , Feminino , Humanos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/patologia , Masculino , Microscopia Imunoeletrônica , Pessoa de Meia-Idade , Nanopartículas , Embolia Pulmonar/sangue , Embolia Pulmonar/epidemiologia , Embolia Pulmonar/etiologia , Fatores de Risco , Trombina/biossíntese , Trombofilia/etiologia , Tromboembolia Venosa/sangue , Tromboembolia Venosa/etiologia
4.
J Biomater Appl ; 35(7): 743-753, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32807016

RESUMO

In this study, turmeric's active ingredient (Curcumin) was encapsulated into RGD modified Liposomes (RGD-Lip-Cur) its cytotoxic effect on the breast cancer cell line (MCF-7) was evaluated by MTT, flow cytometry and Caspase assay. Liposomes were characterized using transmission electron microscopy (TEM). Results demonstrated that the liposomes were spherical in shape, ranging from 70 to 100 nm. MTT assay revealed that RGD-Lip-Cur had a significant cytotoxic effect on MCF-7 cells at concentrations of 32, 16 and 4 µg/ml compared to Lip-Cur (P < 0.05) and curcumin (P < 0.01). The apoptosis assay demonstrated that RGD-Lip-Cur induces the apoptosis in MCF-7 cells (39.6% vs 40.2% for initial and secondary apoptosis) significantly more than Lip-Cur (67.7% vs 9.16% for initial and secondary apoptosis) and free curcumin (7.84% vs 38.8% for initial and secondary apoptosis). Moreover, caspase assay showed that RGD-Lip-Cur activates caspase 3/7 compared to Lip-Cur (P < 0.05) and free curcumin (P < 0.01). The RGD-Lip-Cur was similar to the control group and had no significant cytotoxicity effect. It is concluded that RGD-Lip-Cur as a novel carrier have high cytotoxicity effect on breast cancer cell line (MCF-7).


Assuntos
Neoplasias da Mama/tratamento farmacológico , Curcumina/química , Sistemas de Liberação de Medicamentos , Lipossomos/química , Oligopeptídeos/farmacologia , Antineoplásicos/farmacologia , Apoptose , Sobrevivência Celular , Feminino , Humanos , Células MCF-7 , Microscopia Eletrônica de Transmissão , Tamanho da Partícula
5.
ACS Chem Neurosci ; 11(19): 3161-3173, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-32886481

RESUMO

There is an intense search for natural compounds that can inhibit the oligomerization and fibrillation of α-synuclein (α-Syn), whose aggregation is key to the development of Parkinson's disease (PD). Rosa damascena is a medicinal herb widely used in Middle Eastern food, ceremonies, and perfumes. The herb is known to contain many different polyphenols. Here we investigated the existence of α-Syn fibrillation inhibitors in R. damascena extract. Different HPLC fractions of the extract were assessed in α-Syn fibrillation and toxicity assays. The most active fractions led to the formation of more α-Syn oligomers but with less toxicity to SH-SY5Y cells, according to MTT and LDH assays. LC-MS analysis identified gallic acid, kaempferol 3-glucoside, kaempferol-3-O-ß-rutinoside, and quercetin which were subsequently shown to be strong α-Syn fibrillation inhibitors. Our results highlight the benefits of R. damascena extract to combat PD at the population level.


Assuntos
Rosa , alfa-Sinucleína , Flavonoides/farmacologia , Glicosídeos/farmacologia , Humanos , Fenóis/toxicidade
6.
Sci Rep ; 10(1): 6129, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32273549

RESUMO

To eliminate the microbial infection from an injury site, various modalities have been developed such as dressings and human skin substitutes. However, the high amount of reactive oxygen species, microbial infection, and damaging extracellular matrix remain as the main challenges for the wound healing process. In this study, for the first time, green synthesized silver nanoparticles (AgNPs) using Teucrium polium extract were embedded in poly lactic acid/poly ethylene glycol (PLA/PEG) film to provide absorbable wound dressing, with antioxidant and antibacterial features. The physicochemical analysis demonstrated, production of AgNPs with size approximately 32.2 nm and confirmed the presence of phytoconstituents on their surface. The antibacterial assessments exhibited a concentration-dependent sensitivity of Staphylococcus aureus and Pseudomonas aeruginosa toward biosynthesized AgNPs, which showed a suitable safety profile in human macrophage cells. Furthermore, oxidant scavenging assays demonstrated exploitation of plant extract as a reducing agent, endows antioxidant activity to biogenic AgNPs. The formation of PLA/PEG nanofilm and entrapment of AgNPs into their matrix were clearly confirmed by scanning electron microscopy. More importantly, antibacterial examination demonstrated that the introduction of biogenic AgNPs into PLA/PEG nanofibers led to complete growth inhibition of P. aeruginosa and S. aureus. In summary, the simultaneous antioxidant activity and antimicrobial activity of the novel biogenic AgNPs/PLA/PEG nanofilm showed its potential for application as wound dressing.


Assuntos
Antibacterianos/síntese química , Antioxidantes/síntese química , Nanopartículas Metálicas/química , Cicatrização , Antibacterianos/efeitos adversos , Antibacterianos/farmacologia , Antioxidantes/efeitos adversos , Antioxidantes/farmacologia , Humanos , Lactatos/química , Macrófagos/efeitos dos fármacos , Polietilenoglicóis/química , Pseudomonas aeruginosa/efeitos dos fármacos , Prata/química , Staphylococcus aureus/efeitos dos fármacos
7.
Int J Biol Macromol ; 147: 98-108, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31923504

RESUMO

Protein aggregation to form amyloid is associated with many human diseases, increasing the need to develop inhibitors of this process. Here we evaluate the ability of derivatives of the small organic compound noscapine, derived from the opium poppy, to inhibit fibrillation of the model protein insulin. We combined biophysical methods to assess insulin stability and aggregation with computational docking and cell viability studies to identify the most potent derivatives. The best aggregation inhibitor (a phenyl derivative of N-nornoscapine) also demonstrated the highest ability to stabilize native insulin against thermal denaturation. This compound maintained insulin largely in the monomeric and natively folded state under fibrillation conditions and also decreased insulin aggregate toxicity against human neuroblastoma SH-SY5Y cells. The inhibitory effects were specific for insulin fibrillation, as the noscapine compounds did not inhibit fibrillation of other proteins such as α-synuclein, Aß, and FapC. Our data demonstrate that compounds which stabilize the folded native state of a protein can not only inhibit fibrillation but also decrease the toxicity of the mature fibrillar aggregates of insulin protein.


Assuntos
Amiloide/química , Insulina/química , Noscapina/farmacologia , Peptídeos beta-Amiloides/metabolismo , Benzotiazóis/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Cinética , Simulação de Acoplamento Molecular , Noscapina/síntese química , Noscapina/química , Desnaturação Proteica , Estrutura Secundária de Proteína , Temperatura , alfa-Sinucleína/metabolismo
8.
Biomolecules ; 9(11)2019 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-31717821

RESUMO

Self-assembly of proteins to ß-sheet rich amyloid fibrils is commonly observed in various neurodegenerative diseases. However, amyloid also occurs in the extracellular matrix of bacterial biofilm, which protects bacteria from environmental stress and antibiotics. Many Pseudomonas strains produce functional amyloid where the main component is the highly fibrillation-prone protein FapC. FapC fibrillation may be inhibited by small molecules such as plant polyphenols, which are already known to inhibit formation of pathogenic amyloid, but the mechanism and biological impact of inhibition is unclear. Here, we elucidate how polyphenols modify the self-assembly of functional amyloid, with particular focus on epigallocatechin gallate (EGCG), penta-O-galloyl-ß-d-glucose (PGG), baicalein, oleuropein, and procyanidin B2. We find EGCG and PGG to be the best inhibitors. These compounds inhibit amyloid formation by redirecting the aggregation of FapC monomers into oligomeric species, which according to small-angle X-ray scattering (SAXS) measurements organize into core-shell complexes of short axis diameters 25-26 nm consisting of ~7 monomers. Using peptide arrays, we identify EGCG-binding sites in FapC's linker regions, C and N-terminal parts, and high amyloidogenic sequences located in the R2 and R3 repeats. We correlate our biophysical observations to biological impact by demonstrating that the extent of amyloid inhibition by the different inhibitors correlated with their ability to reduce biofilm, highlighting the potential of anti-amyloid polyphenols as therapeutic agents against biofilm infections.


Assuntos
Amiloide/metabolismo , Catequina/análogos & derivados , Proteínas Fúngicas/metabolismo , Taninos Hidrolisáveis/farmacologia , Polifenóis/farmacologia , Pseudomonas/efeitos dos fármacos , Amiloide/genética , Biofilmes/efeitos dos fármacos , Catequina/farmacologia , Proteínas Fúngicas/genética , Agregados Proteicos/efeitos dos fármacos , Pseudomonas/fisiologia
9.
J Biol Chem ; 294(31): 11817-11828, 2019 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-31197037

RESUMO

The serine protease high-temperature requirement protein A1 (HtrA1) is associated with protein-misfolding disorders such as Alzheimer's disease and transforming growth factor ß-induced protein (TGFBIp)-linked corneal dystrophy. In this study, using several biochemical and biophysical approaches, including recombinant protein expression, LC-MS/MS and 2DE analyses, and thioflavin T (ThT) fluorescence assays for amyloid fibril detection, and FTIR assays, we investigated the role of HtrA1 both in normal TGFBIp turnover and in corneal amyloid formation. We show that HtrA1 can cleave WT TGFBIp but prefers amyloidogenic variants. Corneal TGFBIp is extensively processed in healthy people, resulting in C-terminal degradation products spanning the FAS1-4 domain of TGFBIp. We show here that HtrA1 cleaves the WT FAS1-4 domain only inefficiently, whereas the amyloidogenic FAS1-4 mutations transform this domain into a considerably better HTRA1 substrate. Moreover, HtrA1 cleavage of the mutant FAS1-4 domains generated peptides capable of forming in vitro amyloid aggregates. Significantly, these peptides have been previously identified in amyloid deposits in vivo, supporting the idea that HtrA1 is a causative agent for TGFBIp-associated amyloidosis in corneal dystrophy. In summary, our results indicate that TGFBIp is an HtrA1 substrate and that some mutations in the gene encoding TGFBIp cause aberrant HtrA1-mediated processing that results in amyloidogenesis in corneal dystrophies.


Assuntos
Amiloide/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Serina Peptidase 1 de Requerimento de Alta Temperatura A/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Idoso de 80 Anos ou mais , Cromatografia Líquida de Alta Pressão , Córnea/metabolismo , Doenças da Córnea/metabolismo , Doenças da Córnea/patologia , Proteínas da Matriz Extracelular/química , Proteínas da Matriz Extracelular/genética , Serina Peptidase 1 de Requerimento de Alta Temperatura A/genética , Humanos , Mutagênese Sítio-Dirigida , Peptídeos/análise , Peptídeos/metabolismo , Domínios Proteicos , Dobramento de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Espectrometria de Massas em Tandem , Fator de Crescimento Transformador beta/química , Fator de Crescimento Transformador beta/genética
10.
Exp Cell Res ; 379(1): 73-82, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30922921

RESUMO

Glioblastoma multiforme (GBM) is the most common and malignant type of primary brain tumor and is characterized by its sudden onset and invasive growth into the brain parenchyma. The invasive tumor cells evade conventional treatments and are thought to be responsible for the ubiquitous tumor regrowth. Understanding the behavior of these invasive tumor cells and their response to therapeutic agents could help improve patient outcome. In this study, we present a GBM tumorsphere migration model with high biological complexity to study migrating GBM cells in a quantitative and qualitative manner. We demonstrated that the in vitro migration model could be used to investigate both inhibition and stimulation of cell migration with oxaliplatin and GBM-derived extracellular vesicles, respectively. The intercellular heterogeneity within the GBM tumorspheres was examined by immunofluorescent staining of nestin/vimentin and GFAP, which showed nestin and vimentin being highly expressed in the periphery of tumorspheres and GFAP mostly in cells in the tumorsphere core. We further showed that this phenotypic gradient was present in vivo after implanting dissociated GBM tumorspheres, with the cells migrating away from the tumor being nestin-positive and GFAP-negative. These results indicate that GBM tumorsphere migration models, such as the one presented here, could provide a more detailed insight into GBM cell biology and prove highly relevant as a pre-clinical platform for drug screening and assessing drug response in the treatment of GBM.


Assuntos
Neoplasias Encefálicas/patologia , Movimento Celular/fisiologia , Glioblastoma/patologia , Animais , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Estudos de Avaliação como Assunto , Regulação Neoplásica da Expressão Gênica/fisiologia , Glioblastoma/metabolismo , Humanos , Camundongos , Camundongos Nus , Nestina/metabolismo , Vimentina/metabolismo
11.
PLoS One ; 14(3): e0213663, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30901378

RESUMO

Parkinson's Disease (PD) is a neurodegenerative disease for which there currently is no cure. Aggregation of the pre-synaptic protein α-synuclein (aSN) into oligomers (αSOs) is believed to play a key role in PD pathology, but little is known about αSO formation in vivo and how they induce neurodegeneration. Both the naturally occurring polyunsaturated fatty acid docosahexaenoic acid (DHA) and the lipid peroxidation product 4-hydroxynonenal (HNE), strongly upregulated during ROS conditions, stimulate the formation of αSOs, highlighting a potential role in PD. Yet, insight into αSOs structure and biological effects is still limited as most oligomer preparations studied to date are heterogeneous in composition. Here we have aggregated aSN in the presence of HNE and DHA and purified the αSOs using size exclusion chromatography. Both compounds stimulate formation of spherical αSOs containing anti-parallel ß-sheet structure which have the same shape as unmodified αSOs though ca. 2-fold larger. Furthermore, the yield and stabilities of these oligomers are significantly higher than for unmodified aSN. Both modified and unmodified αSOs permeabilize synthetic vesicles, show high co-localisation with glutamatergic synapses and decrease Long Term Potentiation (LTP), in line with the reported synaptotoxic effects of αSOs. We conclude that DHA- and HNE-αSOs are convenient models for pathogenic disease-associated αSOs in PD.


Assuntos
Epitopos/química , Potenciação de Longa Duração/efeitos dos fármacos , Doença de Parkinson/fisiopatologia , alfa-Sinucleína/química , Aldeídos/química , Animais , Dicroísmo Circular , Ácidos Docosa-Hexaenoicos/química , Ácidos Graxos Insaturados/química , Fluoresceínas/química , Glutamina/química , Hipocampo/química , Humanos , Luz , Peroxidação de Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Força Atômica , Neurônios/química , Doença de Parkinson/tratamento farmacológico , Ligação Proteica , Estrutura Secundária de Proteína , Ratos , Espalhamento de Radiação , Espectroscopia de Infravermelho com Transformada de Fourier , Sinapses
12.
Front Plant Sci ; 10: 148, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30815009

RESUMO

The ability of proteins to aggregate to form well-organized ß-sheet rich amyloid fibrils is increasingly viewed as a general if regrettable property of the polypeptide chain. Aggregation leads to diseases such as amyloidosis and neurodegeneration in humans and various mammalian species but is also found in a functional variety in both animals and microbes. However, there are to our knowledge no reports of amyloid formation in plants. Plants are also the source of a large number of aggregation-inhibiting compounds. We reasoned that the two phenomena could be connected and that one of (many) preconditions for plant longevity is the ability to suppress unwanted protein aggregation. In support of this, we show that while protein extracts from the sugar maple tree Acer saccharum fibrillate readily on their own, this process is efficiently abolished by addition of small molecule extracts from the same plant. Further analysis of 44 plants showed a correlation between plant longevity and ability to inhibit protein aggregation. Extracts from the best performing plant, the sugar maple, were subjected to chromatographic fractionation, leading to the identification of a large number of compounds, many of which were shown to inhibit aggregation in vitro. One cautious interpretation is that it may have been advantageous for plants to maintain an efficient collection of aggregation-inhibiting metabolites as long as they do not impair metabolite function. From a practical perspective, our results indicate that long-lived plants may be particularly appropriate sources of new anti-aggregation compounds with therapeutic potential.

13.
J Biol Chem ; 294(11): 4215-4232, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30655291

RESUMO

Aggregation of α-synuclein (αSN) is implicated in neuronal degeneration in Parkinson's disease and has prompted searches for natural compounds inhibiting αSN aggregation and reducing its tendency to form toxic oligomers. Oil from the olive tree (Olea europaea L.) represents the main source of fat in the Mediterranean diet and contains variable levels of phenolic compounds, many structurally related to the compound oleuropein. Here, using αSN aggregation, fibrillation, size-exclusion chromatography-multiangle light scattering (SEC-MALS)-based assays, and toxicity assays, we systematically screened the fruit extracts of 15 different olive varieties to identify compounds that can inhibit αSN aggregation and oligomer toxicity and also have antioxidant activity. Polyphenol composition differed markedly among varieties. The variety with the most effective antioxidant and aggregation activities, Koroneiki, combined strong inhibition of αSN fibril nucleation and elongation with strong disaggregation activity on preformed fibrils and prevented the formation of toxic αSN oligomers. Fractionation of the Koroneiki extract identified oleuropein aglycone, hydroxyl oleuropein aglycone, and oleuropein as key compounds responsible for the differences in inhibition across the extracts. These phenolic compounds inhibited αSN amyloidogenesis by directing αSN monomers into small αSN oligomers with lower toxicity, thereby suppressing the subsequent fibril growth phase. Our results highlight the molecular consequences of differences in the level of effective phenolic compounds in different olive varieties, insights that have implications for long-term human health.


Assuntos
Frutas/química , Iridoides/farmacologia , Olea/química , alfa-Sinucleína/antagonistas & inibidores , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cromatografia em Gel , Relação Dose-Resposta a Droga , Humanos , Glucosídeos Iridoides , Iridoides/química , Iridoides/isolamento & purificação , Luz , Agregados Proteicos/efeitos dos fármacos , Relação Estrutura-Atividade , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo
14.
PLoS One ; 14(1): e0210835, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30640949

RESUMO

Multiple myeloma (MM) patients have increased risk of developing venous thromboembolism, but the underlying mechanisms and the effect on the coagulation system of the disease and the current cancer therapies are not known. It is possible that cancer-associated extracellular vesicles (EV), carrying tissue factor (TF) and procoagulant phospholipids (PPL) may play a role in thrombogenesis. The aim of this study was to perform an in-depth analysis of procoagulant activity of small and large EVs isolated from 20 MM patients at diagnosis and after receiving first-line treatment compared with 20 healthy control subjects. Differential ultracentrifugation at 20,000 × g and 100,000 × g were used to isolate EVs for quantitative and phenotypical analysis through nanoparticle tracking analysis, Western blotting and transmission electron microscopy. The isolated EVs were analyzed for procoagulant activity using the calibrated automated thrombogram technique, a factor Xa-based activity assay, and the STA Procoag-PPL assay. In general, MM patients contained more EVs, and immunoelectron microscopy confirmed the presence of CD9- and CD38-positive EVs. EVs in the 20,000 × g pellets from MM patients exerted procoagulant activity visualized by increased thrombin generation and both TF and PPL activity. This effect diminished during treatment, with the most prominent effect observed in the high-dose chemotherapy eligible patients after induction therapy with bortezomib, cyclophosphamide, and dexamethasone. In conclusion, the EVs in patients with MM carrying TF and PPL are thus capable of exerting procoagulant activity.


Assuntos
Vesículas Extracelulares/metabolismo , Mieloma Múltiplo/sangue , Tromboplastina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Coagulação Sanguínea , Estudos de Casos e Controles , Vesículas Extracelulares/ultraestrutura , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/complicações , Mieloma Múltiplo/tratamento farmacológico , Fosfolipídeos/sangue , Tromboembolia Venosa/sangue , Tromboembolia Venosa/etiologia
15.
Microbes Infect ; 21(2): 73-84, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30528899

RESUMO

Infections caused by the intracellular bacterium Chlamydia trachomatis are a global health burden affecting more than 100 million people annually causing damaging long-lasting infections. In this review, we will present and discuss important aspects of the interaction between C. trachomatis and monocytes/macrophages.


Assuntos
Infecções por Chlamydia/imunologia , Chlamydia trachomatis/imunologia , Infecções por Chlamydia/microbiologia , Humanos , Macrófagos/imunologia , Macrófagos/microbiologia , Monócitos/imunologia , Monócitos/microbiologia
16.
Biochim Biophys Acta Proteins Proteom ; 1867(5): 519-528, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30471451

RESUMO

Lipids often play an important role in the initial steps of fibrillation. The melanosomal protein Pmel17 forms amyloid in vivo and contains a highly amyloidogenic Repeat domain (RPT), important for melanin biosynthesis. RPT fibrillation is influenced by two lysolipids, the anionic lysophosphatidylglycerol (LPG) and zwitterionic lysophosphatidylcholine (LPC), both present in vivo at elevated concentrations in melanosomes, organelles in which Pmel17 aggregate. Here we investigate the interaction of RPT with both LPG and LPC using small-angle X-ray scattering (SAXS), isothermal titration calorimetry (ITC), electron microscopy, fluorescence and circular dichroism (CD) spectroscopy. Under non-shaking conditions, both lipids promote fibrillation but this is driven by different interactions with RPT. Each RPT binds >40 LPG molecules but only weak interactions are seen with LPC. Above LPG's criticial micelle concentration (cmc), LPG and RPT form connected micelles where RPT binds to the surface as beads on a string with core-shell structures. Binding to LPG only induces α-helical structure well above the cmc, while LPC has no measurable effect on the protein structure. While low (but still super-cmc) concentrations of LPG strongly promote aggregation, at higher LPG concentrations (10 mM), only ~ one RPT binds per micelle, inhibiting amyloid formation. ITC and SAXS reveal some interactions between the zwitterionic lipid LPC and RPT below the cmc but little above the cmc. Nevertheless, LPC only promotes aggregation above the cmc and this process is not inhibited by high LPC concentrations, suggesting that monomers and micelles cooperate to influence amyloid formation.


Assuntos
Amiloide/química , Lisofosfatidilcolinas/química , Lisofosfolipídeos/química , Antígeno gp100 de Melanoma/química , Agregação Patológica de Proteínas , Domínios Proteicos
17.
Nanoscale ; 10(19): 9174-9185, 2018 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-29725687

RESUMO

The protein α-synuclein (αSN) aggregates to form fibrils in neuronal cells of Parkinson's patients. Here we report on the effect of neutral (zwitterionic) nanoliposomes (NLPs), supplemented with cholesterol (NLP-Chol) and decorated with PEG (NLP-Chol-PEG), on αSN aggregation and neurotoxicity. Both NLPs retard αSN fibrillization in a concentration-independent fashion. They do so largely by increasing lag time (formation of fibrillization nuclei) rather than elongation (extension of existing nuclei). Interactions between neutral NLPs and αSN may locate to the N-terminus of the protein. This interaction can even perturb the interaction of αSN with negatively charged NLPs which induces an α-helical structure in αSN. This interaction was found to occur throughout the fibrillization process. Both NLP-Chol and NLP-Chol-PEG were shown to be biocompatible in vitro, and to reduce αSN neurotoxicity and reactive oxygen species (ROS) levels with no influence on intracellular calcium in neuronal cells, emphasizing a prospective role for NLPs in reducing αSN pathogenicity in vivo as well as utility as a vehicle for drug delivery.


Assuntos
Lipossomos/química , Nanopartículas/química , Neurônios/efeitos dos fármacos , Doença de Parkinson/terapia , alfa-Sinucleína/química , 1,2-Dipalmitoilfosfatidilcolina/química , Animais , Cálcio/metabolismo , Colesterol/química , Humanos , Células PC12 , Polietilenoglicóis/química , Ratos , Espécies Reativas de Oxigênio/metabolismo
18.
J Extracell Vesicles ; 7(1): 1454777, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29696077

RESUMO

Tissue factor (TF) is the main initiator of coagulation and procoagulant phospholipids (PPL) are key components in promoting coagulation activity in blood. Both TF and PPL may be presented on the surface of extracellular vesicles (EVs), thus contributing to their procoagulant activity. These EVs may constitute a substantial part of pathological hypercoagulability that is responsible for triggering a higher risk of thrombosis in certain patients. The aim of this study was to describe a model system for the isolation of EVs required for investigating their effect on coagulation. Differential ultracentrifugation (DUC) with and without a single washing step was used to isolate and evaluate the procoagulant capacity of EVs from healthy volunteers through analysis of thrombin generation and PPL activity. Ultracentrifugation at 20,000 × g and 100,000 × g resulted in pellets containing larger vesicles and smaller vesicles, respectively. Isolation yield of particle concentration was assessed by nanoparticle tracking analysis. Immunoelectron microscopy and western blotting revealed vesicles positive for the commonly used EV-marker CD9. Plasma proteins and lipoproteins were co-isolated with the EVs; however, application of a washing step clearly diminished the amount of contaminants. The isolated EVs were capable of enhancing thrombin generation, mainly due to PPL predominantly present in pellets from 20,000 × g centrifugation, and correlated with the activity measured by a PPL activity assay. Thus, DUC was proficient for the isolation of EVs with minimal contamination from plasma proteins and lipoproteins, and the setup can be used to study EV-associated procoagulant activity. This may be useful in determining the procoagulant activity of EVs in patients at potentially increased risk of developing thrombosis, e.g. cancer patients. Abbreviations: TF: Tissue factor; PL: Phospholipids; EVs: Extracellular vesicles; FXa: Activated coagulation factor X; TGA: Thrombin generation assay; PPL: Procoagulant phospholipids; DUC: Differential ultracentrifugation; NTA: Nanoparticle tracking analysis; TEM: Transmission electron microscopy; SPP: Standard pool plasma; CTI: Corn trypsin inhibitor; 20K: 20,000 × g; 100K: 100,000 × g; FVIII: Coagulation factor VIII.

19.
Colloids Surf B Biointerfaces ; 161: 578-587, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29149763

RESUMO

Despite extensive studies of the effects of herbal-derived small molecules in the biopharmaceutical and biomedical sciences, their low solubility and stability remain a challenge. Here we focus on baicalein, a small molecule showing potential against neurodegenerative diseases such as Parkinson's and Alzheimer's. However, therapeutic usage in vivo is challenged by low solubility and stability. To address this we have applied neutrally-charged nanoliposome (NLP) as carrier for baicalein. Baicalein was incorporated into NLP to form NLP-Ba at molar baicalain:lipid ratios of up to 1:3, giving a drug entrapment efficiency of 96.71%, slow release of approximately 22% after a week and increased baicalein stability up to 27%. Ascorbic acid increased baicalein's stability further, particularly when incorporated in NLP where baicalein stability intensified by 53% in NLP-Ba. Moreover, NLP-Ba did not show significant cytotoxic effects against neurons; rather, showed considerable protective effect against reactive oxygen species. In addition, NLP promoted internalization of baicalein into cells, showing good biocompatibility. We conclude that NLP-Ba can enhance baicalein's therapeutic potential in neurodegenerative diseases.


Assuntos
Flavanonas/química , Lipossomos/química , Nanoestruturas/química , Neurônios/metabolismo , Animais , Antioxidantes/química , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Flavanonas/farmacocinética , Flavanonas/farmacologia , Humanos , Lipossomos/ultraestrutura , Microscopia Eletrônica de Transmissão , Nanoestruturas/ultraestrutura , Neurônios/efeitos dos fármacos , Células PC12 , Ratos , Espécies Reativas de Oxigênio/metabolismo
20.
Data Brief ; 15: 511-516, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29085871

RESUMO

The datasets presented in this article are related to the research articles entitled "Neutrophil Extracellular Traps in Ulcerative Colitis: A Proteome Analysis of Intestinal Biopsies" (Bennike et al., 2015 [1]), and "Proteome Analysis of Rheumatoid Arthritis Gut Mucosa" (Bennike et al., 2017 [2]). The colon mucosa represents the main interacting surface of the gut microbiota and the immune system. Studies have found an altered composition of the gut microbiota in rheumatoid arthritis patients (Zhang et al., 2015; Vaahtovuo et al., 2008; Hazenberg et al., 1992) [5], [6], [7] and inflammatory bowel disease patients (Morgan et al., 2012; Abraham and Medzhitov, 2011; Bennike, 2014) [8], [9], [10]. Therefore, we characterized the proteome of colon mucosa biopsies from 10 inflammatory bowel disease ulcerative colitis (UC) patients, 11 gastrointestinal healthy rheumatoid arthritis (RA) patients, and 10 controls. We conducted the sample preparation and liquid chromatography mass spectrometry (LC-MS/MS) analysis of all samples in one batch, enabling label-free comparison between all biopsies. The datasets are made publicly available to enable critical or extended analyses. The proteomics data and search results, have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifiers PXD001608 for ulcerative colitis and control samples, and PXD003082 for rheumatoid arthritis samples.

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