ABSTRACT
Epigenetic mechanisms such as DNA methylation and histone modification are important in stem cell differentiation. Methylation is principally associated with transcriptional repression, and histone acetylation is correlated with an active chromatin state. We determined the effects of these epigenetic mechanisms on adipocyte differentiation in mesenchymal stem cells (MSCs) derived from bone marrow (BM-MSCs) and adipose tissue (ADSCs) using the chromatin-modifying agents trichostatin A (TSA), a histone deacetylase inhibitor, and 5-aza-2′-deoxycytidine (5azadC), a demethylating agent. Subconfluent MSC cultures were treated with 5, 50, or 500 nM TSA or with 1, 10, or 100 µM 5azadC for 2 days before the initiation of adipogenesis. The differentiation was quantified and expression of the adipocyte genes PPARG and FABP4 and of the anti-adipocyte gene GATA2 was evaluated. TSA decreased adipogenesis, except in BM-MSCs treated with 5 nM TSA. Only treatment with 500 nM TSA decreased cell proliferation. 5azadC treatment decreased proliferation and adipocyte differentiation in all conditions evaluated, resulting in the downregulation of PPARG and FABP4 and the upregulation of GATA2. The response to treatment was stronger in ADSCs than in BM-MSCs, suggesting that epigenetic memories may differ between cells of different origins. As epigenetic signatures affect differentiation, it should be possible to direct the use of MSCs in cell therapies to improve process efficiency by considering the various sources available.
Subject(s)
Adult , Humans , Middle Aged , Adipocytes/drug effects , Cell Differentiation/drug effects , Deoxycytidine/pharmacology , Histone Deacetylase Inhibitors/pharmacology , Hydroxamic Acids/pharmacology , Mesenchymal Stem Cells/drug effects , Adipocytes/cytology , Blotting, Western , Cells, Cultured , Cell Proliferation/drug effects , DNA Methylation , Epigenomics , Fluorescent Antibody Technique , Polymerase Chain Reaction/methods , Up-RegulationABSTRACT
The process of Trypanosoma cruzi metacyclogenesis involves the transformation of noninfective epimastigotes into metacyclic trypomastigotes, which are the pathogenic form. The analysis of stage-specific genes during T. cruzi metacyclogenesis may provide insight into the mechanisms involved in the regulation of gene expression in trypanosomatids. It may also improve the understanding of the mechanisms responsible for the pathology of Chagas disease, and could lead to the identification of new targets for chemotherapy of this disease. We have demonstrated that during metacyclogenesis the expression of several genes is controlled at the translational level by an alternative regulatory mechanism. This mechanism may involve the mobilization of mRNA to the translation machinery. We have been using self-made T. cruzi microarrays to investigate the role of polysomal mobilization in modulating gene expression during metacyclogenesis
Subject(s)
Animals , Gene Expression Regulation , Genes, Protozoan , Trypanosoma cruzi/genetics , Trypanosoma cruzi/growth & development , Life Cycle Stages/genetics , Trypanosoma cruzi/pathogenicityABSTRACT
As implicacoes clinicas decorrentes das grandes resseccoes intestinais sao hoje assunto de grande interesse para os cirurgioes, devido o numero crescente de pacientes que sobrevivem ao ato operatorio. Os diversos recursos para o tratamento da sindrome do intestino curto incluem a alimentacao parenteral e varios metodos cirurgicos que visam aumentar o tempo de transito intestinal e, portanto, a absorcao dos nutrientes. A interposicao de um segmento de colon distal entre os cotos de intestino delgado remanescente, vem mostrando resultados alentadores no campo experimental. As transformacoes da mucosa deste segmento de colon interposto vem sendo estudadas e se constituem em uma etapa de uma linha de pesquisa iniciada em 1974 na Escola Paulista de Medicina...
Subject(s)
Animals , Rats , Glucose/metabolism , Intestinal Absorption , Colon/surgery , Colon/physiology , Jejunum/surgery , Ileum/surgeryABSTRACT
Amphiphilic proteins were partially purified from culture-derived metacyclic trypomastigotes of the CL and Colombian strains and of the Dm 28c clone of T. cruzi by the use of Triton X-114. These proteins were subjected to one-and two-dimensional polyacrylamide electrophoresis in the presence of sodium dodecyl sulphate. Relatively simple protein profiles with only 5 to 6 major bands were obtained. The CL and Colombian strains produced at least one additional major protein band (86 kDa) compared to the Dm 28c proteins. Trypomastigote amphiphilic proteins displayed both electrophoretic mobilities and isoelectric points identical to those of two polypeptides precipitated by a rabbit antiserum which recognized metacyclic trypomastigote-specific surface antigens. The partial purification of the T. cruzi amphiphilic proteins with Triton X-114 may provide a simple preparative step for the study of these differentiation-related polypeptides, as well as for the study of strain-specific (glyco)proteins and of their possible biological role
Subject(s)
Animals , Glycoproteins/isolation & purification , Membrane Proteins/isolation & purification , Polyethylene Glycols , Trypanosoma cruzi/analysis , Antigens, Protozoan/analysis , Electrophoresis, Polyacrylamide Gel , Epitopes , Trypanosoma cruzi/immunologySubject(s)
Animals , Rats , Cyanoacrylates , Intestine, Small , Ligation , Polypropylenes , Suture TechniquesABSTRACT
Os autores descrevem um caso de molestia de Crohn e adenocarcinoma localizados no ileo terminal. O diagnostico de molestia de Crohn foi baseado em dados clinicos e radiologicos 12 anos antes da comprovacao da co-existencia daquelas duas molestias. A indicacao cirurgica foi realizada quando surgiu o quadro de obstrucao intestinal. Ressaltam a dificuldade de se estabelecer o diagnostico da associacao das duas doencas no pre-operatorio. O diagnostico so pode ser feito baseado nos dados anatomo-patologicos da peca operatoria com o exame minucioso de multiplos cortes histologicos. A revisao da literatuta permitiu verificar que existem apenas 39 casos descritos, em que as duas doencas estavam associadas no ileo terminal. As publicacoes a esse respeito foram feitas somente em tres paises: Estados Unidos, Inglaterra e Canada. O presente caso constitui o primeiro descrito na literatura brasileira
Subject(s)
Humans , Male , Animals , Crohn Disease , Ileal Neoplasms , AdenocarcinomaABSTRACT
Os autores realizaram estudo experimental em caes, comparando o comprometimento pulmonar apos injecoes endotraqueais de suco gastrico colhido por sonda nasogastrica, com e sem administracao previa de cimetidine e injecoes de soro fisiologico. Comprovaram alteracoes pulmonares bem mais evidentes e intensidade maior de inflamacao, nos animais em que se injetou suco gastrico sem cimetidine. Concluiram que a cimetidine possui acao protetora contra o dano pulmonar que se estabelece na pneumonia aspirativa
Subject(s)
Male , Animals , Dogs , Cimetidine , Lung , Gastric JuiceABSTRACT
As resseccoes intestinais extensas constituem uma situacao grave, com alta taxa de mortalidade. Neste trabalho, sao analisados os aspectos clinicos de 21 doentes submetidos a resseccao intestinal de 2/3 ou mais de jejuno-ileo. Destes, 8 tinham resseccao acima de 81% de jejuno-ileo e os 13 restantes entre 66 e 80%. A taxa de mortalidade foi de 85,7%, sendo que 55,55% faleceram na fase de reanimacao pos-operatoria. A infeccao e a desnutricao foram as principais causas de morte