RESUMO
LEF1 antisense RNA 1 (LEF1-AS1) is an antisense long non-coding RNA encoded in the lymphoid enhancer-binding factor 1 (LEF1) locus. LEF1-AS1 is a conserved transcript dysregulated in hematopoiesis. This study aimed to functionally characterize the role of this transcript in myeloid malignancy and explore a possible regulatory effect of LEF1-AS1 upon LEF1. We show that LEF1-AS1 is highly expressed in normal hematopoietic stem cells but barely detectable in myeloid malignant cell lines. Additionally, bone marrow cells from myelodysplastic syndrome (n=12) and acute myeloid malignancy patients (n=28) expressed significantly reduced levels of LEF1-AS1 compared to healthy controls (n=15). Artificial LEF1-AS1 over-expression inhibited proliferation in HL60 and led to an upregulation of tumor suppressors p21 and p27, and reduced ERK1/2 activation. Unexpectedly, no underlying modulation of LEF1 was detected. Ectopic expression of LEF1-AS1 also inhibited proliferation in HELA, a cell line lacking endogenous expression of LEF1, supporting a LEF1-independent mechanism. Additionally, transient over-expression of LEF1-AS1 in AML patient cells also led to reduced proliferation and colony formation capacity. We used a mass spectrometry-based proteomics approach. Proteomic quantification identified the modulation of an important metabolic regulator, Fumarase, and concomitant accumulation of the metabolite fumarate.
Assuntos
Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Leucemia Mieloide Aguda/patologia , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Síndromes Mielodisplásicas/patologia , RNA Longo não Codificante/genética , Estudos de Casos e Controles , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Fator 1 de Ligação ao Facilitador Linfoide/genética , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Prognóstico , Taxa de Sobrevida , Células Tumorais CultivadasRESUMO
Due to the increasing demand for a bone marrow study model, we developed a natural scaffold from decellularized bovine bone marrow (DeBM). The obtained bioscaffold was analyzed after the decellularization process; histological staining, scanning and transmission electron microscopy confirmed the preservation of its native 3D-architecture; including blood vessels and cell niches as well as the integrity of important components of the extracellular matrix; Collagen III, IV and fibronectin. In addition to biochemical composition, physical properties of the bone marrow were also conserved. We evaluated the suitability of this bio-scaffold as a tridimensional culture platform. Seeding experiments with umbilical cord-derived hematopoietic stem cells and human bone marrow stromal cell line HS5 demonstrated that this scaffold is capable of supporting hematopoietic and stromal cell adhesion and proliferation without the need of exogenous factors. DeBM provided an inductive environment for the repopulation of the bone marrow inducing the expression of SDF-1, HGF and SCF by seeded stromal cells. The presence of these potent hematopoietic chemoattractants would be crucial for ex vivo long-term culture of HSCs, and for recreating the natural microenvironment of the bone marrow for bioengineering applications. We conclude that the decellularization process succeeded in preserving the 3D structure and mechanical properties of the bone marrow. The resulting scaffold is suitable for cell culture, representing an advantageous bone marrow experimental model, and potentially an effective platform for CD34+ HSC expansion and differentiation for clinical applications.
Assuntos
Medula Óssea , Células-Tronco Hematopoéticas/citologia , Animais , Bovinos , Células Cultivadas , Técnicas de Cocultura , Humanos , Células-Tronco Mesenquimais/citologia , Tamanho da PartículaRESUMO
Se utilizo una batería de pruebas demoradas (estafilococo, estreptococo, toxoide tetánico , Proteus mirabilis, candidina y tricofitina) con el objetivo de evaluar la inmunidad celular in vivo en 87 personas de más de 60 años supuestamente sanas. Se determinó el grado de respuesta mediante la sumade las medias de los diámetros de las induraciones a lo que se denominó puntuación media total (PMT)que fue para los hombres 14mm y para las mujeres 12mm. Los resultados se compararon por sexos y grupos etáreos
Assuntos
Humanos , Idoso , Idoso , Anergia Clonal , Hipersensibilidade Tardia , Imunidade CelularRESUMO
Se muestran los resultados obtenidos de la utilización de un ElISA de doble anticuerpo y el método de inmunofluorescencia indirecta para la identificación de aislamientos del virus de la encefalomielitis equina del este realizados en los sitemas celulares Vero XL-1. Los resultados obtenidos mediante ambas técnicas fueron del 100 por ciento de coincidencia con la identificación por neutralización. Utilizando las primeras se pudo detectar el virus entre 6 y 8 horas posinoculación. Los resultados obtenidos utilizandon las células XL-2 fueron mejores que con las células Vero