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1.
Am J Clin Nutr ; 119(4): 927-948, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38569787

RESUMO

BACKGROUND: A global move toward consumption of diets from sustainable sources is required to protect planetary health. As this dietary transition will result in greater reliance on plant-based protein sources, the impact on micronutrient (MN) intakes and status is unknown. OBJECTIVE: Evaluate the evidence of effects on intakes and status of selected MNs resulting from changes in dietary intakes to reduce environmental impact. Selected MNs of public health concern were vitamins A, D, and B12, folate, calcium, iron, iodine, and zinc. METHODS: We systematically searched 7 databases from January 2011 to October 2022 and followed the PRISMA guidelines. Eligible studies had to report individual MN intake and/or status data collected in free-living individuals from the year 2000 onward and environmental outcomes. RESULTS: From the 10,965 studies identified, 56 studies were included, mostly from high-income countries (n = 49). Iron (all 56) and iodine (n = 20) were the most and least reported MNs, respectively. There was one randomized controlled trial (RCT) that also provided the only biomarker data, 10 dietary intake studies, and 45 dietary modeling studies, including 29 diet optimization studies. Most studies sought to reduce greenhouse gas emissions or intake of animal-sourced foods. Most results suggested that intakes of zinc, calcium, iodine, and vitamins B12, A, and D would decrease, and total iron and folate would increase in a dietary transition to reduce environmental impacts. Risk of inadequate intakes of zinc, calcium, vitamins A, B12 and D were more likely to increase in the 10 studies that reported nutrient adequacy. Diet optimization (n = 29) demonstrated that meeting nutritional and environmental targets is technically feasible, although acceptability is not guaranteed. CONCLUSIONS: Lower intakes and status of MNs of public health concern are a potential outcome of dietary changes to reduce environmental impacts. Adequate consideration of context and nutritional requirements is required to develop evidence-based recommendations. This study was registered prospectively with PROSPERO (CRD42021239713).


Assuntos
Iodo , Micronutrientes , Humanos , Cálcio , Cálcio da Dieta , Dieta , Ácido Fólico , Ferro , Vitaminas , Zinco , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
J Agric Food Chem ; 71(49): 19265-19276, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38035628

RESUMO

Assessing nutrient bioavailability is complex, as the process involves multiple digestion steps, several cellular environments, and regulatory-metabolic mechanisms. Several in vitro models of different physiological relevance are used to study nutrient absorption, providing significant challenges in data evaluation. However, such in vitro models are needed for mechanistic studies as well as to screen for biological functionality of the food structures designed. This collaborative work aims to put into perspective the wide-range of models to assay the permeability of food compounds considering the particular nature of the different molecules, and, where possible, in vivo data are provided for comparison.


Assuntos
Alimentos , Intestinos , Humanos , Transporte Biológico , Absorção Intestinal , Células CACO-2
3.
Crit Rev Food Sci Nutr ; : 1-19, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37233192

RESUMO

As food transits the gastrointestinal tract, food structures are disrupted and nutrients are absorbed across the gut barrier. In the past decade, great efforts have focused on the creation of a consensus gastrointestinal digestion protocol (i.e., INFOGEST method) to mimic digestion in the upper gut. However, to better determine the fate of food components, it is also critical to mimic food absorption in vitro. This is usually performed by treating polarized epithelial cells (i.e., differentiated Caco-2 monolayers) with food digesta. This food digesta contains digestive enzymes and bile salts, and if following the INFOGEST protocol, at concentrations that although physiologically relevant are harmful to cells. The lack of a harmonized protocol on how to prepare the food digesta samples for downstream Caco-2 studies creates challenges in comparing inter laboratory results. This article aims to critically review the current detoxification practices, highlight potential routes and their limitations, and recommend common approaches to ensure food digesta is biocompatible with Caco-2 monolayers. Our ultimate aim is to agree a harmonized consensus protocol or framework for in vitro studies focused on the absorption of food components across the intestinal barrier.

4.
Food Res Int ; 169: 112815, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37254391

RESUMO

The consumer demand for protein-enriched food products continues to grow, in parallel with consumers' interest in plant based alternatives. The replacement of milk protein by plant protein is likely to be occur predominantly in prepared consumer foods such as nutritional beverages. This study aimed to compare and contrast powder beverages formulated with commercially available dairy versus plant ingredients in terms of protein digestion and gut barrier health. After simulated static in vitro gastrointestinal digestion, the release of free amino acids increased for all model beverages. In addition, the majority of peptides present in digested beverages were < 0.8 kDa in size. Gastrointestinal digestion did not increase the degree of protein hydrolysis in beverages formulated with prehydrolysed milk protein, whey or pea ingredients. A 2 h permeability assessment of digested beverages across the intestinal barrier, using Caco-2/HT-29/MTX co-cultures, revealed reduced transcription of tight junction protein 1, claudin-1 and mucus protein 2 albeit gut barrier impedance was unchanged. IL-8 mRNA levels in cell monolayers was significantly increased with digested fluids treatment but even more so with digesta from hydrolysed milk protein beverage. Overall, the response observed on intestinal biomarkers with digested plant beverages was similar to dairy based beverages supporting the replacement of dairy with plant proteins in powder beverage formulations.


Assuntos
Bebidas , Proteínas de Plantas , Humanos , Pós , Células CACO-2 , Proteínas do Leite/metabolismo , Digestão/fisiologia
5.
Foods ; 12(7)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37048290

RESUMO

The protein composition and digestive characteristics of four commercially available infant formulae (IF) manufactured using bovine (B-IF), caprine (C-IF), soy (S-IF), and rice (R-IF) as a protein source were examined in this study. Plant-based formulae had significantly higher crude protein and non-protein nitrogen (NPN) concentrations. Static in vitro gastrointestinal digestion of these formulae, and subsequent analysis of their digestates, revealed significantly higher proteolysis of B-IF at the end of gastrointestinal digestion compared to the other formulae, as indicated by the significantly higher concentration of free amine groups. Furthermore, differences in structure formation during the gastric phase of digestion were observed, with formation of a more continuous, firmer coagulum by C-IF, while R-IF demonstrated no curd formation likely due to the extensive hydrolysis of these proteins during manufacture. Differences in digestive characteristics between formulae manufactured from these different protein sources may influence the bio-accessibility and bioavailability of nutrients, warranting additional study.

6.
Drug Deliv ; 29(1): 1971-1982, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35762633

RESUMO

Maslinic acid (MA) is a plant-derived, low water-soluble compound with antitumor activity. We have formulated MA in the form of solid lipid nanoparticles (SLNs) with three different shell compositions: Poloxamer 407 (PMA), dicarboxylic acid-Poloxamer 407 (PCMA), and HA-coated PCMA (PCMA-HA). These SLNs improved the solubility of MA up to 7.5 mg/mL, are stable in a wide range of pH, and increase the bioaccessibility of MA after in vitro gastrointestinal (GI) digestion. Gastrointestinal digested SLNs afforded MA delivery across in vitro gut barrier models (21 days old Caco-2 and mucus-producing Caco-2/HT29-MTX co-cultures). The cellular fraction of Caco-2/HT29-MTX co-cultures retained more MA from GI digested PCMA-HA than the Caco-2 monolayers. The concentration of MA reached in the basolateral chamber inhibited growth of pancreatic cancer cells, BxPC3. Finally, confocal microscopy images provided evidence that Nile Red incorporated in MA SLNs was capable of crossing Caco-2 monolayers to be taken up by basolaterally located BxPC3 cells. We have demonstrated that SLNs can be used as nanocarriers of hydrophobic antitumor compounds and that these SLNs are suitable for oral consumption and delivery of the bioactive across the gut barrier.


Assuntos
Lipídeos , Poloxâmero , Triterpenos , Administração Oral , Células CACO-2 , Humanos , Lipídeos/química , Lipossomos , Nanopartículas , Permeabilidade , Triterpenos/administração & dosagem
8.
Free Radic Res ; 53(sup1): 1136-1152, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31510814

RESUMO

Bovine whey proteins are highly valued dairy ingredients. This is primarily due to their amino acid content, digestibility, bioactivities and their processing characteristics. One of the reported bioactivities of whey proteins is antioxidant activity. Numerous dietary intervention trials with humans and animals indicate that consumption of whey products can modulate redox biomarkers to reduce oxidative stress. This bioactivity has in part been assigned to whey peptides using a range of biochemical or cellular assays in vitro. Superimposing whey peptide sequences from gastrointestinal samples, with whey peptides proven to be antioxidant in vitro, allows us to propose peptides from whey likely to exhibit antioxidant activity in the diet. However, whey proteins themselves are targets of oxidation during processing particularly when exposed to high thermal loads and/or extensive processing (e.g. infant formula manufacture). Oxidative damage of whey proteins can be selective with regard to the residues that are modified and are associated with the degree of protein unfolding, with α-Lactalbumin more susceptible than ß-Lactoglobulin. Such oxidative damage may have adverse effects on human health. This review summarises how whey proteins can modulate cellular redox pathways and conversely how whey proteins can be oxidised during processing. Given the extensive processing steps that whey proteins are often subjected to, we conclude that oxidation during processing is likely to compromise the positive health attributes associated with whey proteins.


Assuntos
Antioxidantes/metabolismo , Proteínas do Soro do Leite/metabolismo , Animais , Humanos , Oxirredução , Estresse Oxidativo
9.
Food Chem ; 288: 306-314, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902298

RESUMO

Health benefits are routinely attributed to whey proteins, their hydrolysates and peptides based on in vitro chemical and cellular assays. The objective of this study was to track the fate of whey proteins through the upper gastrointestinal tract, their uptake across the intestinal barrier and then assess the physiological impact to downstream target cells. Simulated gastrointestinal digestion (SGID) released a selection of whey peptides some of which were transported across a Caco-2/HT-29 intestinal barrier, inhibited free radical formation in muscle and liver cells. In addition, SGID of ß-lactoglobulin resulted in the highest concentration of free amino acids (176 nM) arriving on the basolateral side of the co-culture with notable levels of branched chain and sulphur-containing amino acids. In vitro results indicate that consumption of whey proteins will deliver bioactive peptides to target cells.


Assuntos
Estresse Oxidativo/efeitos dos fármacos , Peptídeos/farmacologia , Proteínas do Soro do Leite/metabolismo , Sequência de Aminoácidos , Animais , Transporte Biológico , Células CACO-2 , Bovinos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Trato Gastrointestinal/metabolismo , Células HT29 , Humanos , Lactoglobulinas/metabolismo , Leite/metabolismo , Peptídeos/isolamento & purificação , Peptídeos/metabolismo
10.
J Sci Food Agric ; 99(5): 2629-2635, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30430572

RESUMO

BACKGROUND: To understand the interactions between carriers and functional ingredients is crucial when designing delivery systems, to maximize bioefficacy and functionality. In this study, two different protein matrices were evaluated as means to protect the extract isolated from marjoram leaves (Origanum majorana), casein micelles from fresh skim milk and soy protein isolate (SPI). RESULTS: Marjoram extract was obtained from pressurization of ethanol and water solvent. Protein dispersions of casein and SPI (5 g L-1 each) with or without marjoram extract (0.1-3 mg mL-1 ) were prepared and homogenized. The physicochemical characterization of charge and entrapment efficiency were conducted. The results demonstrated that entrapment efficiency was highly dependent on the carrier itself where SPI formulations showed 20% higher affinity when compared to casein micelles. To investigate the physiological behaviour of the marjoram-protein dispersions, human macrophages were employed. A non-specific inflammatory response of macrophages stimulated with bacterial lipopolysaccharide was measured for TNF-α, IL-1ß and IL-6 cytokine secretion. CONCLUSION: Casein and SPI protein formulations warranted high bioefficacy of marjoram extract, showing their potential as safe carriers. © 2018 Society of Chemical Industry.


Assuntos
Caseínas/química , Cinamatos/química , Depsídeos/química , Origanum/química , Extratos Vegetais/química , Animais , Bovinos , Cinamatos/farmacologia , Depsídeos/farmacologia , Portadores de Fármacos/química , Interleucina-1beta/imunologia , Interleucina-6/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Leite de Soja/química
11.
J Dairy Sci ; 102(1): 54-67, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30527978

RESUMO

Oxidative stress caused by free radicals has been implicated in several human disorders. Dietary antioxidants can help the body to counteract those reactive species and reduce oxidative stress. Antioxidant activity is one of the multiple health-promoting attributes assigned to bovine whey products. The present study investigated whether this activity was retained during upper gut transit using a static simulated in vitro gastrointestinal digestion (SGID) model. The capacity to scavenge free radicals and reduce ferric ion of whey protein isolate (WPI), individual whey proteins, and hydrolysates pre- and post-SGID were measured and compared using various antioxidant assays. In addition, the free AA released from individual protein fractions in physiological gut conditions were characterized. Our results indicated that the antioxidant activity of WPI after exposure to the harsh conditions of the upper gut significantly increased compared with intact WPI. From an antioxidant bioactivity viewpoint, this exposure negates the need for prior hydrolysis of WPI. The whey protein α-lactalbumin showed the highest antioxidant properties post-SGID (oxygen radical absorbance capacity = 1,825.94 ± 50.21 µmol of Trolox equivalents/g of powder) of the 4 major whey proteins tested with the release of the highest amount of the antioxidant AA tryptophan, 6.955 µmol of tryptophan/g of protein. Therefore, α-lactalbumin should be the preferred whey protein in food formulations to boost antioxidant defenses.


Assuntos
Antioxidantes/metabolismo , Trato Gastrointestinal/metabolismo , Proteínas do Soro do Leite/metabolismo , Animais , Antioxidantes/administração & dosagem , Bromelaínas/metabolismo , Bovinos , Cromanos/administração & dosagem , Cromanos/metabolismo , Digestão , Sequestradores de Radicais Livres/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Lactalbumina/metabolismo , Metaloendopeptidases/metabolismo , Proteínas do Leite/metabolismo , Estresse Oxidativo , Subtilisinas/metabolismo , Soro do Leite/química , Proteínas do Soro do Leite/administração & dosagem
12.
J Oleo Sci ; 67(6): 641-649, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29760329

RESUMO

To enhance the curcumin delivery in a variety of food grade matrices namely spray dried ethanolic curcumin in fresh skim milk (Spray dried Cu-SM), a fresh mixture of ethanolic curcumin and skim milk (Fresh Cu-SM) a powder mixture of curcumin and skim milk powder (Powder Cu-SMP) and oil in water emulsion (Emulsion) were studied. The cellular uptake of curcumin from the respective matrices was studied on Caco-2 cell monolayers. Spray dried Cu-SM showed higher encapsulation efficiency compared to a corresponding Powder Cu-SMP and an oil-in-water emulsion (40% oil) bearing curcumin. Furthermore, ethanolic administration of curcumin in spray dried form enhanced the cellular uptake of curcumin considerably higher than non-ethanolic samples (approx. 4 times). Overall, milk protein based vectors were found to perform better than emulsion samples. These findings highlighted the fact that curcumin uptake may be tailored by fine tuning of curcumin delivery vehicles which highlights possible application of powders as functional foods.


Assuntos
Curcumina/administração & dosagem , Curcumina/metabolismo , Matriz Extracelular/metabolismo , Leite , Óleos , Água , Animais , Células CACO-2 , Emulsões , Alimento Funcional , Humanos , Pós
13.
Food Res Int ; 92: 128-137, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28290290

RESUMO

Structuring of delivery matrices in foods aquires careful designing for optimal delivery and subsiquent absorption of the beneficial compounds in the gut. There has been quite improvement in mimicking digestion and absorption in vitro but as of yet little is understood on mucus interference in nutrient absorption Therefore in this study interactions of human intestinal mucus with milk and soy phospholipids liposomes carring hydrophilic (epigallocatechin-3-gallate) or hydrophobic (ß-carotene) bioactive molecules were investigated. Liposomes of about 100nm were obtained using microfluidization and their behaviour with the human intestinal mucus were evaluated using drop shape tensiometry. The chemistry of the liposomes (milk or soy) and the encapsulated bioactive structure can affect the viscoelastic behaviour of the complex itself. Empty or loaded liposomes were differently interacting with the mucus at the interface. Mucus-liposomes interactions were also studied using cell cultures, Caco-2 (without mucus) and cocultures Caco-2/HT29-MTX (mucus producing). The interaction of mucus layer with liposomes was at some extent aligned with rheological studies. This work demonstrated that delivery systems may interact with the mucosal surface of intestinal cells, and in vitro approaches allow for screening of such interactions. These highlights could help us in carefully designing the delivery systems and moreover choosing the right carrier and/or bioactive that does not jeopardize the optimal delivery of the bioactive structure.


Assuntos
Lipossomos/metabolismo , Muco/metabolismo , Animais , Células CACO-2 , Catequina/administração & dosagem , Catequina/análogos & derivados , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Células HT29 , Humanos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Absorção Intestinal , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Leite/química , Reologia , Temperatura , beta Caroteno/administração & dosagem
14.
Food Funct ; 7(8): 3319-36, 2016 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-27142315

RESUMO

An in depth understanding of the underpinning mechanisms that relate to food disruption and processing in the gastrointestinal tract is necessary to achieve optimal intake of nutrients and their bioefficacy. Although in vivo trials can provide insights on physiological responses of nutrients, in vitro assays are often applied as tools to understand specific mechanisms, or as prescreening methods to determine the factors associated with the uptake of food components in the gastrointestinal tract. In vitro assays are also often utilized to design novel or improved food delivery systems. In this review the available approaches to study delivery and uptake of food bioactives and the associated challenges are discussed. For an in depth understanding of food processing in the gastrointestinal tract, it is necessary to apply multidisciplinary methodologies, at the interface between materials science, chemistry, physics and biology.


Assuntos
Digestão , Trato Gastrointestinal/metabolismo , Micronutrientes/farmacocinética , Carotenoides/administração & dosagem , Carotenoides/farmacocinética , Dieta , Humanos , Mucosa Intestinal/metabolismo , Micronutrientes/administração & dosagem , Polifenóis/administração & dosagem , Polifenóis/farmacocinética
15.
Sci Total Environ ; 472: 273-81, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24291627

RESUMO

In the present work, the sorption of pharmaceutical and personal care products (PPCPs) (acetaminophen, atenolol, carbamazepine, caffeine, naproxen and sulphamethoxazole) onto the natural organic matter (NOM) and the inorganic surfaces of a natural sandy loam sediment was quantified separately. The quantification was based on the PPCP charge, their degree of ionisation, their octanol-water partitioning coefficient (KOW) and the sediment organic carbon fraction (ƒOC). PPCP desorption from the sediment was examined under conditions of infiltrating water containing a high concentration of inorganic ions (mimicking infiltrating reclaimed water), and a low concentration (and smaller diversity) of inorganic ions (mimicking rainwater infiltration). Batch tests were performed using a sediment/water ratio of 1:4 and a PPCP initial concentration ranging from 1 to 100 µg L(-1). The results showed the type and degree of PPCP ionisation to strongly influence the sorption of these compounds onto the sediment. The sorption of cationic species onto the sediment was higher than that of anionic species and mostly reversible; the sorption of neutral species was negligible. The anionic species sorbed less onto the sediment, but also desorbed less easily. More than 70% of the total sorption was due to interaction with mineral surfaces. This holds especially true for cationic species (atenolol and caffeine) which sorption was enhanced by the negative surface charge of the sediment. The presence of inorganic ions had no impact on the desorption of the PPCPs from the sediment. According to the calculated percentages of removal, the mobility followed the order: carbamazepine>acetaminophen>naproxen>atenolol>sulfamethoxazole>caffeine.


Assuntos
Cosméticos/análise , Sedimentos Geológicos/química , Preparações Farmacêuticas/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Adsorção , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Eliminação de Resíduos Líquidos
16.
Vaccine ; 28(30): 4751-7, 2010 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-20471438

RESUMO

Influenza vaccination coverage among health-care workers (HCWs) remains the lowest compared with other priority groups for immunization. Little is known about the acceptability and compliance with the pandemic (H1N1) 2009 influenza vaccine among HCWs during the current campaign. Between 23 December 2009 and 13 January 2010, once the workplace vaccination program was over, we conducted a cross-sectional, questionnaire-based survey at the University Hospital 12 de Octubre (Madrid, Spain). Five hundred twenty-seven HCWs were asked about their influenza immunization history during the 2009-2010 season, as well as the reasons for accepting or declining either the seasonal or pandemic vaccines. Multiple logistic-regression analysis was preformed to identify variables associated with immunization acceptance. A total of 262 HCWs (49.7%) reported having received the seasonal vaccine, while only 87 (16.5%) affirmed having received the pandemic influenza (H1N1) 2009 vaccine. "Self-protection" and "protection of the patient" were the most frequently adduced reasons for acceptance of the pandemic vaccination, whereas the existence of "doubts about vaccine efficacy" and "fear of adverse reactions" were the main arguments for refusal. Simultaneous receipt of the seasonal vaccine (odds ratio [OR]: 0.27; 95% confidence interval [95% CI]: 0.14-0.52) and being a staff (OR: 0.08; 95% CI: 0.04-0.19) or a resident physician (OR: 0.16; 95% CI: 0.05-0.50) emerged as independent predictors for pandemic vaccine acceptance, whereas self-reported membership of a priority group was associated with refusal (OR: 5.98; 95% CI: 1.35-26.5). The pandemic (H1N1) 2009 influenza vaccination coverage among the HCWs in our institution was very low (16.5%), suggesting the role of specific attitudinal barriers and misconceptions about immunization in a global pandemic scenario.


Assuntos
Atitude do Pessoal de Saúde , Hospitais Universitários/estatística & dados numéricos , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Recursos Humanos em Hospital/estatística & dados numéricos , Vacinação/estatística & dados numéricos , Adulto , Estudos Transversais , Surtos de Doenças/prevenção & controle , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Espanha/epidemiologia , Inquéritos e Questionários , Recusa do Paciente ao Tratamento/psicologia , Recusa do Paciente ao Tratamento/estatística & dados numéricos
19.
Proc Natl Acad Sci U S A ; 104(1): 240-5, 2007 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-17182750

RESUMO

Hemolytic uremic syndrome (HUS) is an important cause of acute renal failure in children. Mutations in one or more genes encoding complement-regulatory proteins have been reported in approximately one-third of nondiarrheal, atypical HUS (aHUS) patients, suggesting a defect in the protection of cell surfaces against complement activation in susceptible individuals. Here, we identified a subgroup of aHUS patients showing persistent activation of the complement alternative pathway and found within this subgroup two families with mutations in the gene encoding factor B (BF), a zymogen that carries the catalytic site of the complement alternative pathway convertase (C3bBb). Functional analyses demonstrated that F286L and K323E aHUS-associated BF mutations are gain-of-function mutations that result in enhanced formation of the C3bBb convertase or increased resistance to inactivation by complement regulators. These data expand our understanding of the genetic factors conferring predisposition to aHUS, demonstrate the critical role of the alternative complement pathway in the pathogenesis of aHUS, and provide support for the use of complement-inhibition therapies to prevent or reduce tissue damage caused by dysregulated complement activation.


Assuntos
Fator B do Complemento/genética , Síndrome Hemolítico-Urêmica/genética , Mutação , Antígenos CD55/farmacologia , Fator B do Complemento/química , Fator B do Complemento/fisiologia , Fator H do Complemento/farmacologia , Via Alternativa do Complemento , Síndrome Hemolítico-Urêmica/etiologia , Síndrome Hemolítico-Urêmica/imunologia , Humanos , Relação Estrutura-Atividade
20.
Yeast ; 20(16): 1359-68, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14663828

RESUMO

We cloned a genomic DNA fragment of the yeast Torulaspora delbrueckii by complementation of a Saccharomyces cerevisiae his3 mutant strain. DNA sequence analysis revealed that the fragment contained two complete ORFs, which share a high similarity with S. cerevisiae His3p and Mrp51p, respectively. The cloned TdHIS3 gene fully complemented the his3 mutation of S. cerevisiae, confirming that it encodes for the imidazoleglycerol-phosphate dehydrate of T. delbrueckii. Two additional ORFs, with a high homology to S. cerevisiae PET56 and DED1 genes, were mapped upstream and downstream from TdHIS3 and TdMRP51, respectively. This genetic organization is analogous to that previously found in Saccharomyces kluyveri and Zygosaccharomyces rouxii. The evolutionary significance of gene order in this chromosomal region is analysed and discussed.


Assuntos
Hidroliases/genética , Saccharomycetales/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas de Ciclo Celular/genética , Clonagem Molecular , RNA Helicases DEAD-box , DNA Fúngico/química , DNA Fúngico/genética , Evolução Molecular , Proteínas Fúngicas/genética , Metiltransferases/genética , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , RNA Helicases/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomycetales/enzimologia , Alinhamento de Sequência , Transcrição Gênica
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