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1.
ACS Nano ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916260

RESUMO

Parkinson's disease (PD) is an increasingly prevalent and currently incurable neurodegenerative disorder linked to the accumulation of α-synuclein (αS) protein aggregates in the nervous system. While αS binding to membranes in its monomeric state is correlated to its physiological role, αS oligomerization and subsequent aberrant interactions with lipid bilayers have emerged as key steps in PD-associated neurotoxicity. However, little is known of the mechanisms that govern the interactions of oligomeric αS (OαS) with lipid membranes and the factors that modulate such interactions. This is in large part due to experimental challenges underlying studies of OαS-membrane interactions due to their dynamic and transient nature. Here, we address this challenge by using a suite of microfluidics-based assays that enable in-solution quantification of OαS-membrane interactions. We find that OαS bind more strongly to highly curved, rather than flat, lipid membranes. By comparing the membrane-binding properties of OαS and monomeric αS (MαS), we further demonstrate that OαS bind to membranes with up to 150-fold higher affinity than their monomeric counterparts. Moreover, OαS compete with and displace bound MαS from the membrane surface, suggesting that disruption to the functional binding of MαS to membranes may provide an additional toxicity mechanism in PD. These findings present a binding mechanism of oligomers to model membranes, which can potentially be targeted to inhibit the progression of PD.

2.
Eur J Surg Oncol ; 50(6): 108325, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38636248

RESUMO

BACKGROUND: The incidence of anastomotic leak after colorectal anastomosis in ovarian cancer has been reported to be much lower than that in colorectal cancer patients. Regarding the use of protective manoeuvres (diverting ileostomy) as suggested by clinical guidelines, the goal should be the implementation of a restrictive stoma policy for ovarian cancer patients, given the low rate of anastomotic leakage in this population. MATERIAL AND METHODS: Patients who underwent cytoreduction surgery in a single centre (University Hospital La Fe, Valencia Spain) due to ovarian cancer between January 2010 and June 2023 were classified according to two groups: a non-restrictive stoma policy group (Group A) and a restrictive stoma policy group (Group B). RESULTS: A total of 256 patients were included in the analysis (group A 52 % vs group B 48 %). The use of protective diverting ileostomy was lower in the restrictive stoma policy group (14 % vs 6.6 %), and the use of ghost ileostomy was 32 % vs 87 % in groups A and B, respectively (p < 0.00001). No differences were found in the anastomotic leak rate, which was 5.2 % in the non-restrictive group and 3.2 % in the restrictive stoma policy group (p = 0.54). CONCLUSION: The use of a restrictive stoma policy based on the use of ghost ileostomy reduces the rate of diverting ileostomy in patients with ovarian cancer after colorectal resection and anastomosis. Furthermore, this policy is not associated with an increased rate of anastomotic leakage nor with an increased rate of morbi-mortality related to the leak.


Assuntos
Anastomose Cirúrgica , Fístula Anastomótica , Ileostomia , Neoplasias Ovarianas , Humanos , Feminino , Neoplasias Ovarianas/cirurgia , Fístula Anastomótica/epidemiologia , Fístula Anastomótica/prevenção & controle , Anastomose Cirúrgica/métodos , Pessoa de Meia-Idade , Idoso , Procedimentos Cirúrgicos de Citorredução/métodos , Estudos Retrospectivos , Estomas Cirúrgicos , Adulto , Reto/cirurgia
3.
Food Funct ; 15(8): 4552-4563, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38584501

RESUMO

The exploration of edible insects, specifically Alphitobius diaperinus and Tenebrio molitor, as sustainable sources of protein for human consumption is an emerging field. However, research into their effects on intestinal health, especially in relation to inflammation and permeability, remains limited. Using ex vivo and in vivo models of intestinal health and disease, in this study we assess the impact of the above insects on intestinal function by focusing on inflammation, barrier dysfunction and morphological changes. Initially, human intestinal explants were exposed to in vitro-digested extracts of these insects, almond and beef. Immune secretome analysis showed that the inflammatory response to insect-treated samples was comparatively lower than it was for samples exposed to almond and beef. Animal studies using yellow mealworm (Tenebrio molitor) and buffalo (Alphitobius diaperinus) flours were then used to evaluate their safety in healthy rats and LPS-induced intestinal dysfunction rats. Chronic administration of these insect-derived flours showed no adverse effects on behavior, metabolism, intestinal morphology or immune response (such as inflammation or allergy markers) in healthy Wistar rats. Notably, in rats subjected to proinflammatory LPS-induced intestinal dysfunction, T. molitor consumption did not exacerbate symptoms, nor did it increase allergic responses. These findings validate the safety of these edible insects under healthy conditions, demonstrate their innocuity in a model of intestinal dysfunction, and underscore their promise as sustainable and nutritionally valuable dietary protein sources.


Assuntos
Insetos Comestíveis , Proteínas de Insetos , Ratos Wistar , Tenebrio , Animais , Ratos , Humanos , Masculino , Intestinos/efeitos dos fármacos , Intestinos/imunologia , Enteropatias , Modelos Animais de Doenças , Feminino , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos
4.
Foods ; 13(2)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38254523

RESUMO

Several species of hybrid fruits, such as citrus, grapes, blueberries, apples, tomatoes, and lingonberries among others, have attracted scientific attention in recent years, especially due to their reported antioxidant and anti-inflammatory properties. The bagasse, leaves, bark, and seeds of these hybrid fruits have large amounts of polyphenols, such as flavonoids, which act as potent antioxidants. Several studies have been carried out in cellular models of neurotoxicity of the extract of these fruits, to document the beneficial effects for human health, as well as to prove its antiproliferative effect in cancer cells. In the present review, through a synthesis of existing information in the scientific literature, we demonstrate that hybrid fruits are a source of antioxidant and bioactive compounds, which act in the inhibition of diseases such as cancer, diabetes, and inflammatory and neurodegenerative diseases, and consequently improving human health.

5.
J Am Chem Soc ; 145(47): 25776-25788, 2023 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-37972287

RESUMO

Misfolded protein oligomers are of central importance in both the diagnosis and treatment of Alzheimer's and Parkinson's diseases. However, accurate high-throughput methods to detect and quantify oligomer populations are still needed. We present here a single-molecule approach for the detection and quantification of oligomeric species. The approach is based on the use of solid-state nanopores and multiplexed DNA barcoding to identify and characterize oligomers from multiple samples. We study α-synuclein oligomers in the presence of several small-molecule inhibitors of α-synuclein aggregation as an illustration of the potential applicability of this method to the development of diagnostic and therapeutic methods for Parkinson's disease.


Assuntos
Nanoporos , Doença de Parkinson , Humanos , alfa-Sinucleína/metabolismo , Doença de Parkinson/metabolismo
6.
Asian Pac J Cancer Prev ; 24(11): 3673-3684, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38019224

RESUMO

OBJECTIVE: Grape hybrids are characterized by different chemical compositions; often with high hybrids are characterized by different chemical compositions, often with a high phenolic content and a specific profile of anthocyanins. The aim of study was to characterize the constituents of hybrid Vitis vinifera L. varieties Sweet Sapphire (SA) and Sweet Surprise (SU) extracts and their influence on apoptosis induction and antiproliferative effects on human prostate cancer cells. METHODS: We used the MTT assay to evaluate the cytotoxic effect of extracts of SA and SU, on the prostate adenocarcinoma cell lines PC-3 and DU-145. To analyze the inhibiting impact by flow cytometry, used 24 and 48 hours. Anthocyanins were quantified by liquid chromatography and analysed by their absorption rate, hepatotoxicity, blood concentration, blood-brain barrier passage ability and maximum recommended dose by in silico approaches. RESULTS: Our results showed that malvidin derivatives present the highest content in both cultivars. We identified 14.46mg/100g malvidin-3-O-glycoside in SA and 2.76 mg/100 g in SU. A reduction in cell viability of DU-145 (45 and 65%) and PC-3 (63 and 67%) cells after 48h treatment with SA and SU, respectively, was found via MTT assay. Flow cytometry showed that the treatment with extracts from SA and SU had an inhibitory impact on cell development due to G2/M arrest and caused a rise in apoptotic cells compared to control group. None of the anthocyanin presented hepatotoxicity as well as blood-brain barrier passage ability. Peonidin 3-O-glucoside had the lower maximum recommended dose as well as the highest intestinal absorption rate. However, delphinidin 3-O-glucoside had the highest blood concentration values. CONCLUSION: The findings of this study highlight the potential of hybrid Vitis vinifera L. varieties as an important source of natural antioxidants and their protective effect against prostate cancer cells as well as elucidate in part their anthocyanin's metabolism.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Neoplasias da Próstata , Vitis , Masculino , Humanos , Apoptose , Antocianinas/farmacologia , Linhagem Celular Tumoral , Pontos de Checagem da Fase G2 do Ciclo Celular , Neoplasias da Próstata/tratamento farmacológico , Óxido de Alumínio , Glucosídeos
7.
Int J Mol Sci ; 24(9)2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37175514

RESUMO

The impact that healthy aging can have on society has raised great interest in understanding aging mechanisms. However, the effects this biological process may have on the gastrointestinal tract (GIT) have not yet been fully described. Results in relation to changes observed in the enteroendocrine system along the GIT are controversial. Grape seed proanthocyanidin extracts (GSPE) have been shown to protect against several pathologies associated with aging. Based on previous results, we hypothesized that a GSPE pre-treatment could prevent the aging processes that affect the enteroendocrine system. To test this hypothesis, we treated 21-month-old female rats with GSPE for 10 days. Eleven weeks after the treatment, we analyzed the effects of GSPE by comparing these aged animals with young animals. Aging induced a greater endocrine response to stimulation in the upper GIT segments (cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1)), a decrease in the mRNA abundance of GLP-1, peptide YY (PYY) and chromogranin A (ChgA) in the colon, and an increase in colonic butyrate. GSPE-treated rats were protected against a decrease in enterohormone expression in the colon. This effect is not directly related to the abundance of microbiome or short-chain fatty acids (SCFA) at this location. GSPE may therefore be effective in preventing a decrease in the colonic abundance of enterohormone expression induced by aging.


Assuntos
Extrato de Sementes de Uva , Proantocianidinas , Ratos , Feminino , Animais , Extrato de Sementes de Uva/farmacologia , Proantocianidinas/farmacologia , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Colecistocinina , Ácidos Graxos Voláteis/metabolismo , Colo/metabolismo
8.
Soc Sci Med ; 326: 115947, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37146355

RESUMO

This paper examines the experiences of adolescents from mixed migratory status families affected by deportation. We analyze the impacts on their mental and emotional health when they are separated from one parent in the United States, forcibly displaced with another to Oaxaca, and experience the consequences of their deportation in Mexico. We use a qualitative and ethnographic methodology. This paper focuses on data from semi-structured interviews and focus groups with 15 parents who had been deported from the United States and 53 adolescents who moved with them to Mexico. The data was collected between 2018 and 2020. The main findings show the existence of emotions that are sustained in the transnational flow and acquire new nuances upon return. They also show the emergence of new conditions related to family separation, all of which have an impact on the adolescents' well-being and on important areas of their lives, such as education. The research contributes to knowledge in two main ways: 1) it addresses the impacts of parental deportation on the well-being of adolescents in mixed-status families, which have typically focused on children; 2) it studies how parental deportation affects the mental and emotional health of adolescents de facto deported to Mexico, a field still little studied.


Assuntos
Emoções , Pais , Criança , Humanos , Adolescente , Estados Unidos , México , Saúde Mental , Saúde do Adolescente
9.
J Endocrinol ; 257(1)2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36688873

RESUMO

Peroxisome proliferator-activated receptor γ (PPARγ) belongs to a family of nuclear receptors that could serve as lipid sensors. PPARγ is the target of a group of insulin sensitizers called thiazolidinediones (TZDs) which regulate the expression of genes involved in glucose and lipid metabolism as well as adipokines that regulate metabolic function in other tissues. Non-alcoholic fatty liver disease (NAFLD) has a high prevalence worldwide and is even higher in patients with obesity and insulin resistance. TZD-mediated activation of PPARγ could serve as a good treatment for NAFLD because TZDs have shown anti-fibrogenic and anti-inflammatory effectsin vitro and increase insulin sensitivity in peripheral tissues which improves liver pathology. However, mechanistic studies in mouse models suggest that the activation of PPARγ in hepatocytes might reduce or limit the therapeutic potential of TZD against NAFLD. In this review, we briefly describe the short history of PPAR isoforms, the relevance of their expression in different tissues, as well as the pathogenesis and potential therapeutics for NAFLD. We also discuss some evidence derived from mouse models that could be useful for endocrinologists to assess tissue-specific roles of PPARs, complement reverse endocrinology approaches, and understand the direct role that PPARγ has in hepatocytes and non-parenchymal cells.


Assuntos
Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Tiazolidinedionas , Animais , Camundongos , Hepatócitos/metabolismo , Resistência à Insulina/fisiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR gama/metabolismo , Tiazolidinedionas/metabolismo , Tiazolidinedionas/uso terapêutico
10.
J Sci Food Agric ; 103(4): 1660-1667, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36324158

RESUMO

BACKGROUND: It has been previously shown that acutely administered insect Alphitobius diaperinus protein increases food intake in rats and modifies the ex vivo enterohormone secretory profile differently than beef or almond proteins. In this study, we aimed to evaluate whether these effects could be maintained for a longer period and determine the underlying mechanisms. RESULTS: We administered two different insect species to rats for 26 days and measured food intake at different time points. Both insect species increased food intake in the first week, but the effect was later lost. Glucagon-like peptide 1 (GLP-1) and ghrelin were measured in plasma and ex vivo, and no chronic effects on their secretion or desensitization were found. Nevertheless, digested A. diaperinus acutely modified GLP-1 and ghrelin secretion ex vivo. CONCLUSION: Our results suggest that increases in food intake could be explained by a local ghrelin reduction acting in the small intestine. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Besouros , Tenebrio , Bovinos , Ratos , Feminino , Animais , Tenebrio/metabolismo , Grelina/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Insetos , Ingestão de Alimentos , Refeições
11.
J Mol Biol ; 435(1): 167825, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36099961

RESUMO

Mutations in the SNCA gene, which encodes the protein α-synuclein, have been linked with early onset Parkinson's disease. The exact nature of this association, however, is still poorly understood. To investigate this problem, we started from the observation that α-synuclein is constitutively N-terminally acetylated, a post-translational modification that alters the charge and structure of α-synuclein molecules and affects their interaction with lipid membranes, as well as their aggregation process. We thus studied five N-terminal acetylated familial variants (A30P, E46K, H50Q, G51D and A53T) of α-synuclein through a wide range of biophysical assays to probe the microscopic steps in their aggregation process and the structures of the resulting aggregates. Our results reveal a great complexity in the combined effects of the disease-related mutations with N-terminal acetylation on the aggregation of α-synuclein, which underscores the great sensitivity to even relatively small perturbations of the behaviour of this protein.


Assuntos
Doença de Parkinson , Agregação Patológica de Proteínas , Processamento de Proteína Pós-Traducional , alfa-Sinucleína , Humanos , Acetilação , alfa-Sinucleína/química , alfa-Sinucleína/genética , Doença de Parkinson/genética , Doença de Parkinson/metabolismo
12.
Food Funct ; 13(20): 10491-10500, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36148543

RESUMO

Grape seed derived procyanidins (GSPE) have been shown to effectively prevent intestinal disarrangements induced by a cafeteria diet in young rats. However, little is known about the effects of procyanidins and cafeteria diet on enterohormone secretion in aged rats, as the ageing processes modify these effects. To study these effects in aged rats, we subjected 21-month-old and young 2-month-old female rats to two sub-chronic preventive GSPE treatments. After three months of cafeteria diet administration, we analysed the basal and stimulated secretion and mRNA expression of CCK, PYY and GLP-1, caecal SCFA and intestinal sizes. We found that the effects of a cafeteria diet on the basal duodenal CCK secretion are age dependent. GLP-1 in the ileum was not modified regardless of the rat's age, and GSPE preventive effects differed in the two age groups. GSPE pre-treatment reduced GLP-1, PYY and ChgA in mRNA in aged ileum tissue, while the cafeteria diet increased these in aged colon. The GSPE treatments only modified low-abundance SCFAs. The cafeteria diet in aged rats increases the caecum size differently from that in young rats and GSPE pre-treatment prevents this increase. Therefore, ageing modifies nutrient sensing, and the cafeteria diet acts mainly on the duodenum and colon, while procyanidins have a larger effect on the ileum.


Assuntos
Extrato de Sementes de Uva , Proantocianidinas , Animais , Dieta , Feminino , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Extrato de Sementes de Uva/farmacologia , Proantocianidinas/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar
13.
Biochemistry ; 61(17): 1743-1756, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-35944093

RESUMO

Parkinson's disease is associated with the aberrant aggregation of α-synuclein. Although the causes of this process are still unclear, post-translational modifications of α-synuclein are likely to play a modulatory role. Since α-synuclein is constitutively N-terminally acetylated, we investigated how this post-translational modification alters the aggregation behavior of this protein. By applying a three-pronged aggregation kinetics approach, we observed that N-terminal acetylation results in a reduced rate of lipid-induced aggregation and slows down both elongation and fibril-catalyzed aggregate proliferation. An analysis of the amyloid fibrils produced by the aggregation process revealed different morphologies for the acetylated and non-acetylated forms in both lipid-induced aggregation and seed-induced aggregation assays. In addition, we found that fibrils formed by acetylated α-synuclein exhibit a lower ß-sheet content. These findings indicate that N-terminal acetylation of α-synuclein alters its lipid-dependent aggregation behavior, reduces its rate of in vitro aggregation, and affects the structural properties of its fibrillar aggregates.


Assuntos
Amiloide , alfa-Sinucleína , Acetilação , Amiloide/química , Lipídeos , Agregados Proteicos , Processamento de Proteína Pós-Traducional , alfa-Sinucleína/química
14.
Nutrients ; 14(7)2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35406076

RESUMO

Protein is considered the most satiating macronutrient, and its effect on satiety and food intake is source-dependent. For the first time, we compared the effect of the administration of an insect or almond preload, both containing 20 g of protein, on appetite and food intake in human subjects. Participants consumed both foods and a vehicle as a liquid preload on three separate days. They were then offered a breakfast and lunch buffet meal at which food intake was measured. Visual analogue scale (VAS) questionnaires were completed following the three preloads to assess appetite and other sensations. At breakfast, reduced energy intake was observed for both preloads compared with vehicle. At lunch, food intake only differed in the insect group, which consumed more than the vehicle. Insect preload increased the total amount of protein ingested with a slight increase in total energy consumed, differently than almond, which significantly increased total protein and energy consumed. There was no correlation between indigestion-sensation ratings and food intake. Moreover, the insect preload resulted in lower sleepiness and tiredness ratings compared with the almond preload. Thus, insect-derived protein may be suitable as a safe ingredient for snacks intended for elderly or infirm patients who require increased protein intake.


Assuntos
Prunus dulcis , Idoso , Animais , Apetite , Estudos Cross-Over , Ingestão de Alimentos , Ingestão de Energia , Humanos , Insetos , Saciação , Lanches , Adulto Jovem
15.
J Pediatr Gastroenterol Nutr ; 74(6): e153-e159, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35221319

RESUMO

OBJECTIVE: To evaluate the effect of a new probiotic strain combination, Ligilactobacillus salivarius subsp infantis PS11603 and Bifidobacterium longum PS10402, on gut bacterial colonization of preterm infants. METHODS: A randomized, double-blind, placebo-controlled study was conducted in preterm infants from 28 weeks + 0days to 30 weeks + 6days of gestation. Thirty preterm infants were randomly selected after birth to receive either probiotics or placebo. Stool samples were collected before product intake and then sequentially during the first weeks of their admission. Classical microbiological, metagenomics and multiplex immunological analyses were performed to assess the bacterial and immune profile of the samples. RESULTS: Twenty-seven infants completed the study (14 vs 13, probiotic and placebo groups). A higher number of participants were colonized by Lactobacilli in the probiotic group than in the placebo group (93% vs 46%; P  = 0.013). Similar results were obtained when analysing bifidobacterial colonization (100% vs 69%; P  = 0.041). Earlier colonization was observed in the probiotics group versus the placebo group, specifically 5 weeks for Lactobacillus and 1 week for Bifidobacterium. Although no effect was observed in the faecal immunological profile, a decreasing trend could be observed in Th17 response during the first week of probiotic treatment. None of the adverse events (AEs) registered were related to product intake. CONCLUSION: Probiotic supplementation with L salivarius PS11603 and B longum subsp. infantis PS10402 enhanced an earlier colonization of Lactobacillus and Bifidobacterium in preterm infants' guts in 5 and 1 week, respectively. A higher number of infants were colonized by Lactobacilli with the probiotics' intake at the end of the study.


Assuntos
Microbioma Gastrointestinal , Probióticos , Bifidobacterium , Método Duplo-Cego , Fezes/microbiologia , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Lactobacillus , Probióticos/uso terapêutico
16.
Urologia ; 89(4): 616-622, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35102794

RESUMO

PURPOSE: The COVID19 pandemic has caused a redistribution of hospital resources. Prioritization strategies are needed in order to organize elective surgeries. We compared the new Medically Necessary Time-Sensitive score (MeNTS) and its factors (disease, procedure, and patient factors) between operated and deferred cases, and also to a subjective priority scale in the Urology department. METHODS: The MeNTS score and a subjective prioritization scale were prospective applied to all patients included on the surgical waiting list from March 10 to September 9, 2020. Mann-Whitney U test was used to compare MeNTS scores between operated and non-operated groups. Kruskal-Wallis test was used to compare MeNTS scores between three subjective priority groups. RESULTS: A total of 150 cases were operated while 100 were deferred. Median total MeNTS score in the operated group was 39.5 whereas in the non-operated group it was 38 (p = 0.135). Median disease factors score was 9.5 in the operated group and 11 in the non-operated group(p = 0.033). Median procedure factors score was 10 in both groups (p = 0.02). Median patient factors score was 17 in the operated group and 18 in the non-operated group (p = 0.210). Disease factors displayed a significant difference between the three subjective priority groups. CONCLUSIONS: Total MeNTS score does not show significant differences between operated and non-operated patients. However, we demonstrate a relationship between MeNTS disease factors and the operated group as well as with the subjective priority scale.


Assuntos
COVID-19 , COVID-19/epidemiologia , Procedimentos Cirúrgicos Eletivos , Humanos , Pandemias , Estudos Prospectivos , SARS-CoV-2
17.
Molecules ; 27(4)2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35209093

RESUMO

A wide variety of oligomeric structures are formed during the aggregation of proteins associated with neurodegenerative diseases. Such soluble oligomers are believed to be key toxic species in the related disorders; therefore, identification of the structural determinants of toxicity is of upmost importance. Here, we analysed toxic oligomers of α-synuclein and its pathological variants in order to identify structural features that could be related to toxicity and found a novel structural polymorphism within G51D oligomers. These G51D oligomers can adopt a variety of ß-sheet-rich structures with differing degrees of α-helical content, and the helical structural content of these oligomers correlates with the level of induced cellular dysfunction in SH-SY5Y cells. This structure-function relationship observed in α-synuclein oligomers thus presents the α-helical structure as another potential structural determinant that may be linked with cellular toxicity in amyloid-related proteins.


Assuntos
Mutação , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismo , Multimerização Proteica , alfa-Sinucleína/química , alfa-Sinucleína/genética , Humanos , Doenças Neurodegenerativas , Agregados Proteicos , Ligação Proteica , Multimerização Proteica/genética , Análise Espectral , alfa-Sinucleína/metabolismo
18.
Food Chem ; 366: 130644, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34311234

RESUMO

Bioactive compounds were extracted using two different extraction solvents (acetone and water) from pulp and whole grape berries derived from hybrid Vitis vinifera L. varieties Sweet sapphire (SP) and Sweet surprise (SU) and were characterised based on a comprehensive metabolomic approach by chromatography coupled with mass spectrometry (UPLC-QTOF-MSE and GC-FID/MS). GC-FID/MS analysis was performed with two different extraction methods (solvent extraction method and solid-phase extraction). Anthocyanins were characterised and quantified by HPLC-UV. The antioxidant potential was assessed by different assays. SP acetone extract from grape skin had the highest mean to DPPH, FRAP, ORAC and phenolic content SP samples, also showed higher anthocyanin content. Globally, 87 phenolic compounds were identified. The relative quantification by UPLC-MSE showed flavonoids the most abundant class. Forty two compounds were found in the volatile fraction of SU, while only thirty one volatile compounds were found in the SP samples.


Assuntos
Vitis , Óxido de Alumínio , Antocianinas/análise , Antioxidantes/análise , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas em Tandem
19.
Proc Natl Acad Sci U S A ; 118(38)2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34518228

RESUMO

Molecular chaperones are key components of the cellular proteostasis network whose role includes the suppression of the formation and proliferation of pathogenic aggregates associated with neurodegenerative diseases. The molecular principles that allow chaperones to recognize misfolded and aggregated proteins remain, however, incompletely understood. To address this challenge, here we probe the thermodynamics and kinetics of the interactions between chaperones and protein aggregates under native solution conditions using a microfluidic platform. We focus on the binding between amyloid fibrils of α-synuclein, associated with Parkinson's disease, to the small heat-shock protein αB-crystallin, a chaperone widely involved in the cellular stress response. We find that αB-crystallin binds to α-synuclein fibrils with high nanomolar affinity and that the binding is driven by entropy rather than enthalpy. Measurements of the change in heat capacity indicate significant entropic gain originates from the disassembly of the oligomeric chaperones that function as an entropic buffer system. These results shed light on the functional roles of chaperone oligomerization and show that chaperones are stored as inactive complexes which are capable of releasing active subunits to target aberrant misfolded species.


Assuntos
Amiloide/metabolismo , Proteínas de Choque Térmico Pequenas/metabolismo , Cadeia B de alfa-Cristalina/metabolismo , alfa-Sinucleína/metabolismo , Entropia , Humanos , Doença de Parkinson/metabolismo , Agregados Proteicos/fisiologia , Proteostase/fisiologia
20.
Nutrients ; 13(6)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208508

RESUMO

Obesity and ageing are current issues of global concern. Adaptive homeostasis is compromised in the elderly, who are more likely to suffer age-related health issues, such as obesity, metabolic syndrome, and cardiovascular disease. The current worldwide prevalence of obesity and higher life expectancy call for new strategies for treating metabolic disorders. Grape-seed proanthocyanidin extract (GSPE) is reported to be effective in ameliorating these pathologies, especially in young animal models. In this study, we aimed to test the effectiveness of GSPE in modulating obesity-related pathologies in aged rats fed an obesogenic diet. To do so, 21-month-old rats were fed a high-fat/high-sucrose diet (cafeteria diet) for 11 weeks. Two time points for GSPE administration (500 mg/kg body weight), i.e., a 10-day preventive GSPE treatment prior to cafeteria diet intervention and a simultaneous GSPE treatment with the cafeteria diet, were assayed. Body weight, metabolic parameters, liver steatosis, and systemic inflammation were analysed. GSPE administered simultaneously with the cafeteria diet was effective in reducing body weight, total adiposity, and liver steatosis. However, the preventive treatment was effective in reducing only mesenteric adiposity in these obese, aged rats. Our results confirm that the simultaneous administration of GSPE improves metabolic disruptions caused by the cafeteria diet also in aged rats.


Assuntos
Extrato de Sementes de Uva/uso terapêutico , Obesidade/tratamento farmacológico , Proantocianidinas/uso terapêutico , Adiposidade/efeitos dos fármacos , Animais , Glicemia/efeitos dos fármacos , Modelos Animais de Doenças , Fígado Gorduroso/tratamento farmacológico , Feminino , Glucagon/sangue , Insulina/sangue , Obesidade/metabolismo , Ratos , Ratos Wistar , Redução de Peso/efeitos dos fármacos
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