104 research outputs found
Frequent mechanical stress suppresses proliferation of mesenchymal stem cells from human bone marrow without loss of multipotency
Mounting evidence indicated that human mesenchymal stem cells (hMSCs) are responsive not only
to biochemical but also to physical cues, such as substrate topography and stiffness. To simulate the
dynamic structures of extracellular environments of the marrow in vivo, we designed a novel surrogate
substrate for marrow derived hMSCs based on physically cross-linked hydrogels whose elasticity can
be adopted dynamically by chemical stimuli. Under frequent mechanical stress, hMSCs grown on
our hydrogel substrates maintain the expression of STRO-1 over 20 d, irrespective of the substrate
elasticity. On exposure to the corresponding induction media, these cultured hMSCs can undergo
adipogenesis and osteogenesis without requiring cell transfer onto other substrates. Moreover,
we demonstrated that our surrogate substrate suppresses the proliferation of hMSCs by up to 90%
without any loss of multiple lineage potential by changing the substrate elasticity every 2nd days.
Such “dynamic in vitro niche” can be used not only for a better understanding of the role of dynamic
mechanical stresses on the fate of hMSCs but also for the synchronized differentiation of adult stem
cells to a specific lineage
Bifidobacterium adolescentis protects against necrotizing enterocolitis and upregulates TOLLIP and SIGIRR in premature neonatal rats
Decreased survival among lung cancer patients with co-morbid tuberculosis and diabetes
Alternative Splicing in the Differentiation of Human Embryonic Stem Cells into Cardiac Precursors
The role of alternative splicing in self-renewal, pluripotency and tissue lineage specification of human embryonic stem cells (hESCs) is largely unknown. To better define these regulatory cues, we modified the H9 hESC line to allow selection of pluripotent hESCs by neomycin resistance and cardiac progenitors by puromycin resistance. Exon-level microarray expression data from undifferentiated hESCs and cardiac and neural precursors were used to identify splice isoforms with cardiac-restricted or common cardiac/neural differentiation expression patterns. Splice events for these groups corresponded to the pathways of cytoskeletal remodeling, RNA splicing, muscle specification, and cell cycle checkpoint control as well as genes with serine/threonine kinase and helicase activity. Using a new program named AltAnalyze (http://www.AltAnalyze.org), we identified novel changes in protein domain and microRNA binding site architecture that were predicted to affect protein function and expression. These included an enrichment of splice isoforms that oppose cell-cycle arrest in hESCs and that promote calcium signaling and cardiac development in cardiac precursors. By combining genome-wide predictions of alternative splicing with new functional annotations, our data suggest potential mechanisms that may influence lineage commitment and hESC maintenance at the level of specific splice isoforms and microRNA regulation
Basic science of osteoarthritis
Osteoarthritis (OA) is a prevalent, disabling disorder of the joints that affects a large population worldwide and for which there is no definitive cure. This review provides critical insights into the basic knowledge on OA that may lead to innovative end efficient new therapeutic regimens. While degradation of the articular cartilage is the hallmark of OA, with altered interactions between chondrocytes and compounds of the extracellular matrix, the subchondral bone has been also described as a key component of the disease, involving specific pathomechanisms controlling its initiation and progression. The identification of such events (and thus of possible targets for therapy) has been made possible by the availability of a number of animal models that aim at reproducing the human pathology, in particular large models of high tibial osteotomy (HTO). From a therapeutic point of view, mesenchymal stem cells (MSCs) represent a promising option for the treatment of OA and may be used concomitantly with functional substitutes integrating scaffolds and drugs/growth factors in tissue engineering setups. Altogether, these advances in the fundamental and experimental knowledge on OA may allow for the generation of improved, adapted therapeutic regimens to treat human OA.(undefined
Quantitative proteomics identifies 38 proteins that are differentially expressed in cucumber in response to cucumber green mottle mosaic virus infection
Conhecimentos e práticas de adolescentes na prevenção de acidentes de trabalho: estudo qualitativo
Hydrodynamic loading in concomitance with exogenous cytokine stimulation modulates differentiation of bovine mesenchymal stem cells towards osteochondral lineages
Study design to examine the potential role of assessment reactivity in the Screening, Motivational Assessment, Referral, and Treatment in Emergency Departments (SMART-ED) protocol
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