Navegando por Palavras-chave "Mucopolissacaridose tipo I"
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- ItemAcesso aberto (Open Access)Alterações bioquímicas e celulares secundárias à deficiência enzimática em modela animal de Mucopolissacaridose tipo I(Universidade Federal de São Paulo (UNIFESP), 2011-03-30) Pereira, Vanessa Gonçalves [UNIFESP]; D'Almeida, Vânia [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)A Mucopolissacaridose tipo I (MPS I) é uma doença de depósito lisossômico autossômica recessiva, causada pela deficiência da enzima alfa-L-iduronidase, responsável pela degradação de dois glicosaminoglicanos: dermatan e heparan sulfatos. Pacientes com MPS I apresentam uma ampla diversidade de manifestações clínicas e, até hoje, não foi possível estabelecer a correlação genótipo-fenótipo. Além disso, somente o acúmulo de glicosaminoglicanos não é suficiente para explicar a heterogeneidade fenotípica. A ampla diversidade de manifestações clínicas é uma característica das doenças de depósito lisossômico, além do acúmulo de metabólitos não diretamente relacionados à deficiência enzimática específica, sugerindo que várias vias bioquímicas e/ou celulares secundárias estejam envolvidas na fisiopatologia destas doenças. Alterações em diversos processos celulares como vias de sinalização, homeostase de Ca2+ intracelular, biossíntese de lipídeos, tráfego intracelular, permeabilização da membrana lisossômica e autofagia já foram identificadas em diferentes doenças de depósito lisossômico. Neste presente estudo, foram avaliados os processos de permeabilização da membrana lisossômica, homeostase de Ca2+ intracelular e autofagia em diferentes tecidos de um modelo animal de MPS I. Em esplenócitos de camundongos com MPS I, foi observada maior quantidade de Ca2+ no retículo endoplasmático e nos lisossomos, e menor quantidade de H+ nos lisossomos, indicando alteração de homeostase iônica nestas células. Foi observada também uma alteração na distribuição de H+ entre os compartimentos celulares, além da presença de cisteíno proteases no citosol, que evidenciam o processo de permeabilização da membrana lisossômica. Além disso, os esplenócitos de camundongos com MPS I apresentaram taxa maior de apoptose, provavelmente ativada pela permeabilização. Em conjunto, essas alterações sugerem que o processo de autofagia também possa estar comprometido neste modelo animal. Em relacao aos marcadores de autofagia, foi observada maior quantidade da proteina Beclina-1 no cerebro dos camundongos com MPS I, indicativo de inducao da autofagia. Nao foram observadas evidencias de acumulo de agregados proteicos pelo bloqueio de autofagia em nenhum dos tecidos estudados (cerebro, figado e baco), pois nao foram encontradas diferencas nas quantidades da proteina p62/SQSTM1. Porem, foi identificada uma isoforma da p62/SQSTM1 de menor tamanho, e a razao entre as isoformas foi diferente entre todos os tecidos, sugerindo que o fluxo de degradacao destas moleculas e tecido-especifico. Alem disso, foram observados baixos niveis de ƒÀ-tubulina nos hepatocitos dos camundongos com MPS I, que provavelmente causam desorganizacao do citoesqueleto e deficiencia no transporte vesicular. Analisados de maneira conjunta, os resultados observados neste presente estudo demonstram que diversas alteracoes bioquimicas e celulares secundarias a deficiencia enzimatica estao envolvidas na fisiopatologia da MPS I, e que essas alteracoes sao tecido-especificas.
- ItemAcesso aberto (Open Access)Análise biomecânica, morfológica e da resposta nociceptiva em modelo animal de Mucopolissacaridose tipo I(Universidade Federal de São Paulo (UNIFESP), 2019-02-28) Ferreira, Nicole Yolanda [UNIFESP]; D'Almeida, Vania [UNIFESP]; Pereira, Vanessa Gonçalves [UNIFESP]; http://lattes.cnpq.br/4126672233843478; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4785189U3; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4471024Y5; Universidade Federal de São Paulo (UNIFESP)Mucopolysaccharidoses (MPS) are a group of inborn errors of metabolism (IEM), in which specific lysosomal enzymes that participate of glycosaminoglycan (GAG) degradation are deficient or inactive. Musculoskeletal impairment is an important component of the morbidity related to the disease, once it causes a major impact in patients’ health and life quality. Characteristics such as decreased enzyme activity and lysosomal storage in different types of cells are observed in MPS I murine models, making them an important and reliable tool for better understanding the pathogenic mechanisms of the disease. Despite all existing evidence regarding musculoskeletal alterations in MPS I, it is still unclear how these influence bone matrix quality and its biomechanical properties. Objective: Evaluate the nociceptive response to heat in 3 and 6-month old wild type (Idua +/+) and MPS I knockout mice (Idua -/-), as well as bone matrix morphological, biomechanical, and histological properties. Method: Nociceptive response to heat from 3 and 6-month old wild type (Idua +/+) and MPS I knockout mice (Idua -/-) was evaluated. In addition, morphological, biomechanical, and histological analysis of femurs from the same group of animals were perfomed. Results and conclusions: No difference was observed in the nociceptive response to heat for all animal groups ang ages. Femurs from 3-month old Idua -/- mice were found to be smaller and less resistant to fracture when compared to their age matched controls. Also, at this age, femurs from 3-month old Idua - /- mice presented important alterations in articular cartilage, trabecular bone architecture, and collagen types I and III deposition. At 6 months of age, femurs from Idua -/- mice were more resistant to fracture than those from Idua +/+. Our results suggest that the clear abnormalities observed in bone matrix and articular cartilage in 3-month old Idua -/- animals caused bone tissue to be less flexible and more likely to fracture, whereas in 6-month old Idua -/- group the ability to withstand more load before fracturing than wild type animals might suggest that at this age bones become more resistant than at 3 months of age.
- ItemAcesso aberto (Open Access)Implementação e padronização de técnicas de dosagem enzimática para detecção de doenças de depósito lisossômico(Universidade Federal de São Paulo (UNIFESP), 2009-02-27) Müller, Karen Barbosa [UNIFESP]; D'Almeida, Vânia [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objectives: To implement and to standardize enzymatic activity techniques using dried blood spots on filter paper for the enzymes -galactosidase A, for the diagnosis of Fabry Disease patients; -iduronidase, for the diagnosis of Mucopolysaccharidosis type I patients; -glucosidase and chitotriosidase, for the diagnosis of Gaucher Disease patients and acid -glucosidase, that allows the diagnosis of Pompe Disease patients; besides the enzyme -galactosidase, that allows assessing the quality of the material. In addition, to determine the cut-off value for each enzyme, that will enable the discrimination between healthy subjects and patients. Methodology: 302 volunteers of both gender were selected, with ages between 18 and 82 years old. Peripheral blood was collected in heparin containing tubes and blood spots were prepared according to the protocol. All enzymatic activity techniques carried out in this work were based in the cleavage of a specific synthetic substrate, by the action of target enzymes which then releases a fluorescent molecule that will be detected by the fluorimeter. Results: The values of enzyme activity obtained in this work were the following (mean±standard deviation; minimum and maximum values), expressed in μmol/L/h: -galactosidase (14,09±4,36; 4,04-29,65); -galactosidase A (4,57±1,37; 1,44-10,67); -iduronidase (3,45±1,21; 1,40-7,78); -glucosidase (4,57±1,37; 1,44-10,67); chitotriosidase (12,88±9,84; 0,00-48,07); -glucosidase (5,41±1,74; 2,10-10,65); also expressed in the ratio of neutral -glucosidase/inhibited acid -glucosidase (13,19±4,26; 5,03-28,58); and as % of acid -glucosidase inhibition (70,66±7,60; 36,38-87,08). The sensibility and specificity values obtained with the comparison of leukocytes and dried blood spots results showed that all techniques are reliable and appropriate. Conclusions: The results from this work enabled us to choose the most accurate cut-off values which to distinguish between healthy subjects and patients with Fabry Disease, Mucopolysaccharidosis type I, Gaucher Disease and Pompe Disease. Enzyme activity values are in agreement with the literature data. The use of dried blood spots for lysosomal disease diagnosis can be considered efficient, inexpensive and simple to be performed.
- ItemAcesso aberto (Open Access)Terapia de reposição da enzima alfa-L-iduronidase recombinante em pacientes portadores de mucopolissacaridose do tipo I: análise de glicosaminoglicanos urinários e correlações clínicas(Universidade Federal de São Paulo (UNIFESP), 2009) Braghiroli, Patricia Santos [UNIFESP]; Toma, Leny [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disease caused by deficiency of -L-iduronidase, which cleaves terminal iduronic acid residues of glycosaminoglycans (GAGs), heparan sulphate (HS) and dermatan sulphate (DS). Impairment of degradation leads to its accumulation and increased urinary excretion, with a wide spectrum of clinical severity. The aim of this work was to evaluate the effects of periodic enzyme replacement therapy (ERT) with recombinant -L-iduronidase in MPS I patients. Three patients were weekly treated with Laronidase (Aldurazyme®), 0,58 mg/kg intravenously. Clinical evaluation and analysis of urinary GAGs were done before and after ERT. Two clinically severe Hurler and one mild Hurler-Scheie patients were enrolled in this study. After 19 to 22 months of treatment, the effects observed herein are in accordance with previous data, showing efficacy of ERT on reducing hepatosplenomegaly and clinical improvements, without changing mental impairment of the Hurler patients. Remarkably were the findings of decreasing DS excretion for all patients, the value not returning to the initial baseline. One exception was for the Hurler- Scheie patient who presented a peak of higher values after 11 months of infusion after interruption of treatment, followed by important decrease after return to ERT. Noteworthy was the case of this same patient, whose DS decreased, whereas a progressive increase of CS was observed. Although CS is not present in MPS I urine, it is the predominant GAG in normal individuals. ERT may not be a cure for these diseases and improvement cannot reach all the tissues and affected organs, but represents a safe alternative choice of treatment while gene therapy is not available for humans.