Effects of reconstituted collagen matrix on fates of mouse embryonic stem cells before and after induction for chondrogenic differentiation

Embryonic stem (ES) cells are pluripotent cells with great potential in regenerative medicine. However, controlling their differentiation toward homogeneous lineages is challenging. In this study, we aim to investigate the effects of reconstituted 3D collagen matrix on the fates of mouse ES (mES) cells before and after induction for chondrogenic differentiation. Specifically, mES cells were encapsulated and cultured in 3D collagen microspheres and exposed to induction signals at different time points. Growth characteristics and differentiation status of mES cells were then evaluated. Collagen microspheres provided a suitable microenvironment supporting mES cell growth and maintaining their undifferentiated status for certain period of time. At later time points, the proportion of undifferentiated mES cells gradually decreased, accompanied by increasing proportions of mesenchymal progenitor cells. This suggests the inductive role of collagen matrix in differentiating mES cells toward mesenchymal lineages. Moreover, a lower initial collagen monomer concentration facilitated the differentiation of mES cells into chondrogenic lineages, while induction at a later time point associated with a more advanced stage of chondrogenic differentiation. This indicates that both the initial collagen concentration and the time to induce differentiation significantly affected the fates of mES cells. This study contributes to future development of ES cell-based therapies. © Copyright 2009, Mary Ann Liebert, Inc.published_or_final_versionThe 7th Annual Meeting of the International Society for Stem Cell Research (ISSCR), Barcelona, Spain, 8-11 July 2009. In Tissue Engineering. Part A, 2009, v. 15 n. 10, p. 3071-308

Role of autophagy in chondrocyte differentiation

Poster presentation - Theme 3: Development & stem cellsMaintaining cell homeostasis during cellular differentiation is critical for the cell survival. Therefore, the balance between protein biogenesis and degradation is tightly regulated. The removal of the after-used and unwanted substances is not only important for protein turnover but also in regulating cellular differentiation and developmental process. The degradation of protein relies on two well-known systems, the Ubiquitin-proteasome system (UPS) and Autophagy-lysosomal system (ALS). Here, using the unique organization of the growth plate that depicts temporal and spatial “life time” of chondrocytes during ...postprin

The developmental roles of the extracellular matrix: Beyond structure to regulation

Cells in multicellular organisms are surrounded by a complex three-dimensional macromolecular extracellular matrix (ECM). This matrix, traditionally thought to serve a structural function providing support and strength to cells within tissues, is increasingly being recognized as having pleiotropic effects in development and growth. Elucidation of the role that the ECM plays in developmental processes has been significantly advanced by studying the phenotypic and developmental consequences of specific genetic alterations of ECM components in the mouse. These studies have revealed the enormous contribution of the ECM to the regulation of key processes in morphogenesis and organogenesis, such as cell adhesion, proliferation, specification, migration, survival, and differentiation. The ECM interacts with signaling molecules and morphogens thereby modulating their activities. This review considers these advances in our understanding of the function of ECM proteins during development, extending beyond their structural capacity, to embrace their new roles in intercellula signaling. © 2009 Springer-Verlag.postprin

Uncoupled endochondral ossification in transgenic mice expressing type X collagen with mutations in the NC1 domain

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Sedlin and prostaglandin E2 dehydrogenase - interactions and implications for spondyloepiphyseal dysplasia tarda

Session D - Genomic Disorders: abstract no. D020Spondyloepiphyseal dysplasia tarda (SEDT) is a rare X-linked, late-onset skeletal disease. Affected individuals develop phenotypes in their early childhood, displaying barrel-shaped chests, vertebral bodies malformation, flattened disc spaces and premature osteoarthritis in weight-bearing joints. The disease was found linked to the gene SEDL coding for the protein sedlin. Sedlin is one of the subunits of the TRAPP (Transport Protein Particle) complex, which is responsible for vesicle tethering during endoplasmic reticulum-to-golgi transport. Although sedlin is known to function in intracellular trafficking, the reason why mutations in a trafficking protein lead to a skeletal disease remains unknown. To address this, four missense mutations (D47Y, S73L, F83S and V130D) of sedlin observed in SEDT patients were studied. Except D47Y, the other three mutations cause proteosomal degradation of sedlin in cultured cells, whereas the D47Y mutation had a minor effect on Bet3 binding to sedlin. Pull-down assay was performed to identify novel sedlin interacting partners. 15-hydroxyprostaglandin dehydrogenase (PGDH) was pulled down and the interaction was confirmed in cell culture system. Sedlin activates PGDH activity in vitro. By confocal microscopy, sedlin was also found to colocalize with PGDH in the cytosol. PGDH catalyzes the degradation of prostaglandin E2, which affects cartilage and bone growth. Further investigation is ongoing to understand the function of sedlin and the mechanism of disease for SEDT.postprintThe 1st International Congress on Research of Rare and Orphan Diseases (RE(ACT) 2012), Basel, Switzerland, 29 February-2 March 2012. In Brochure of RE(ACT)® 2012, 2012, p. 11

Software engineering sub-ontology for specific software development

In this paper we propose software engineering sub ontology. We called it application-specific ontology, for specific software development. It enables remote team members browsing, searching, sharing, and authoring ontological data under the distributed software engineering projects environment. We transform explicit meaningful human knowledge into application-specific ontology, where knowledge structures and semantics are linked, and we go through a formal hand-shaking agreement establishing process before the semantic contents are updated in ontology repositories. The application-specific ontology is used for communication over project agreement to facilitate better, highly consistent communications and formalized domain knowledge sharing. We assume that object-oriented development is deployed in the distributed projects. The knowledge of object-oriented development formed in the application-specific ontology clarifies the object-oriented development concepts in a machine understandable form. Software agent, for example, can be utilised to extract information

Predictive insights for improving the resilience of global food security using artificial intelligence

Unabated pressures on food systems affect food security on a global scale. A human-centric artificial intelligence-based probabilistic approach is used in this paper to perform a unified analysis of data from the Global Food Security Index (GFSI). The significance of this intuitive probabilistic reasoning approach for predictive forecasting lies in its simplicity and user-friendliness to people who may not be trained in classical computer science or in software programming. In this approach, predictive modeling using a counterfactual probabilistic reasoning analysis of the GFSI dataset can be utilized to reveal the interplay and tensions between the variables that underlie food affordability, food availability, food quality and safety, and the resilience of natural resources. Exemplars are provided in this paper to illustrate how computational simulations can be used to produce forecasts of good and bad conditions in food security using multi-variant optimizations. The forecast of these future scenarios is useful for informing policy makers and stakeholders across domain verticals, so they can make decisions that are favorable to global food security

Front-line management of indolent non-Hodgkin lymphoma in Australia. Part 2: mantle cell lymphoma and marginal zone lymphoma

Mantle cell lymphoma (MCL) and the marginal zone lymphoma (MZL) subtypes (nodal MZL, extra-nodal MZL of mucosa-associated lymphoid tissue (MALT lymphoma) and splenic MZL) are uncommon lymphoma subtypes, accounting for less than 5-10% of all non-Hodgkin lymphoma. The evidence base for therapy is therefore limited and enrolment into clinical trials is preferred. Outcomes for patients with MCL have been steadily improving mainly due to the adoption of more intense strategies in younger patients, the use of rituximab maintenance and the recent introduction of bendamustine in older patients. MZL is a more heterogeneous group of cancer with both nodal, extra-nodal and splenic subtypes. Extranodal MZL may be associated with autoimmune or infectious aetiologies, and can respond to eradication of the causative pathogen. Proton pump inhibitor plus dual antibiotics in Helicobacter pylori positive gastric MALT lymphoma is curative in many patients. Watchful waiting is appropriate in most patients with asymptomatic advanced stage disease, which tends to behave in a particularly indolent manner. Other options for symptomatic disease include splenectomy, chemoimmunotherapy with rituximab and, more recently, targeted therapies

Visible photoluminescence in ZnO tetrapod and multipod structures

The investigation of the properties of ZnO tetrapod and multipod structures using scanning electron microscopy, X-ray diffraction, photoluminescence (PL) and electron paramagnetic resonance (EPR) spectroscopy was discussed. The ZnO samples were fabricated by heating a mixture of ZnO, GeO2 and graphite at 1100°C in order to modify the morphology of the fabricated structures. The room temperature of PL was measured by using a HeCd laser excitation source (325 nm). It was found that the green PL was due to transition between a shallow donor and deep acceptor in the absence of g ≈ 1.96 EPR signal and transition between the conduction band and deep acceptor in the absence of g ≈ 1.96 EPR signal.published_or_final_versio

sPDZD2: a novel negative modulator of hedgehog signaling

Poster Presentation - Theme 3: Development & stem cellsPDZD2 is a multi-PDZ domain-containing protein of unknown function in early development. It is proteolytically cleaved to generate its secreted form, sPDZD2. Human PDZD2 is mapped to chromosome 5p13.2, which co-localizes with the disease-associated gene in a family of Brachydactyly Type A1 (BDA1) patients, suggesting involvement of PDZD2 in limb development. Hedgehog (Hh) is an important morphogen that dictates tissue patterning during embryonic development and recent studies showed that mutations in Indian Hedgehog (IHH) resulted in ...postprin