17 research outputs found
Pathogenic protease expression in murine OA is critically dependent upon mechanical joint loading
Establishment of computational biology in Greece and Cyprus: Past, present, and future.
We review the establishment of computational biology in Greece and Cyprus from its inception to date and issue recommendations for future development. We compare output to other countries of similar geography, economy, and sizeâbased on publication counts recorded in the literatureâand predict future growth based on those counts as well as national priority areas. Our analysis may be pertinent to wider national or regional communities with challenges and opportunities emerging from the rapid expansion of the field and related industries. Our recommendations suggest a 2-fold growth margin for the 2 countries, as a realistic expectation for further expansion of the field and the development of a credible roadmap of national priorities, both in terms of research and infrastructure funding
Deletions of Immunoglobulin heavy chain and T cell receptor gene regions are uniquely associated with lymphoid blast transformation of chronic myeloid leukemia
<p>Abstract</p> <p>Background</p> <p>Chronic myelogenous leukemia (CML) results from the neoplastic transformation of a haematopoietic stem cell. The hallmark genetic abnormality of CML is a chimeric <it>BCR/ABL1 </it>fusion gene resulting from the Philadelphia chromosome rearrangement t(9;22)(q34;q11). Clinical and laboratory studies indicate that the <it>BCR/ABL1 </it>fusion protein is essential for initiation, maintenance and progression of CML, yet the event(s) driving the transformation from chronic phase to blast phase are poorly understood.</p> <p>Results</p> <p>Here we report multiple genome aberrations in a collection of 78 CML and 14 control samples by oligonucleotide array comparative genomic hybridization. We found a unique signature of genome deletions within the immunoglobulin heavy chain (<it>IGH</it>) and T cell receptor regions (<it>TCR</it>), frequently accompanied by concomitant loss of sequences within the short arm regions of chromosomes 7 and 9, including <it>IKZF1</it>, <it>HOXA7</it>, <it>CDKN2A/2B</it>, <it>MLLT3</it>, <it>IFNA/B</it>, <it>RNF38</it>, <it>PAX5</it>, <it>JMJD2C </it>and <it>PDCD1LG2 </it>genes.</p> <p>Conclusions</p> <p>None of these genome losses were detected in any of the CML samples with myeloid transformation, chronic phase or controls, indicating that their presence is obligatory for the development of a malignant clone with a lymphoid phenotype. Notably, the coincidental deletions at <it>IGH </it>and <it>TCR </it>regions appear to precede the loss of <it>IKZF1 </it>and/or <it>p16 </it>genes in CML indicating a possible involvement of RAG in these deletions.</p
FISH mapping of Philadelphia negative BCR/ABL1 positive CML
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Suramin inhibits osteoarthritic cartilage degradation by increasing extracellular levels of chondroprotective tissue inhibitor of metalloproteinases 3
Osteoarthritis is a common degenerative joint disease for which no disease-modifying drugs
are currently available. Attempts to treat the disease with small molecule inhibitors of the
metalloproteinases that degrade the cartilage matrix have been hampered by a lack of
specificity. We aimed to inhibit cartilage degradation by augmenting levels of the endogenous
metalloproteinase inhibitor, tissue inhibitor of metalloproteinases 3 (TIMP-3), through
blocking its interaction with the endocytic scavenger receptor, low-density lipoprotein
receptor-related protein 1 (LRP1). We discovered that suramin (C51H40N6O23S6) bound to
TIMP-3 with a KD value of 1.9 ± 0.2 nM and inhibited its endocytosis via LRP1, thus increasing
extracellular levels of TIMP-3 and inhibiting cartilage degradation by the TIMP-3 target
enzyme, adamalysin with thrombospondin motifs 5 (ADAMTS-5). NF279, a structural
analogue of suramin, has increased affinity for TIMP-3 and increased ability to inhibit TIMP-
3 endocytosis and protect cartilage. Suramin is thus a promising scaffold for the development
of novel therapeutics to increase TIMP-3 levels and inhibit cartilage degradation in
osteoarthritis
Retinoic acid is regulated by cartilage injury and is anti-inflammatory in hand osteoarthritis
Nociceptive Sensitizers Are Regulated in Damaged Joint Tissues, Including Articular Cartilage, When Osteoarthritic Mice Display Pain Behavior
OBJECTIVE: Pain is the most common symptom of osteoarthritis (OA), yet where it originates in the joint and how it is driven are unknown. The aim of this study was to identify painâsensitizing molecules that are regulated in the joint when mice subjected to surgical joint destabilization develop OAârelated pain behavior, the tissues in which these molecules are being regulated, and the factors that control their regulation. METHODS: Tenâweekâold mice underwent sham surgery, partial meniscectomy, or surgical destabilization of the medial meniscus (DMM). Painârelated behavior as determined by a variety of methods (testing of responses to von Frey filaments, cold plate testing for cold sensitivity, analgesiometry, incapacitance testing, and forced flexion testing) was assessed weekly. Once painârelated behavior was established, RNA was extracted from either whole joints or microdissected tissue samples (articular cartilage, meniscus, and bone). Reverse transcriptionâpolymerase chain reaction analysis was performed to analyze the expression of 54 genes known to regulate pain sensitization. Cartilage injury assays were performed using avulsed immature hips from wildâtype or genetically modified mice or by explanting articular cartilage from porcine joints preinjected with pharmacologic inhibitors. Levels of nerve growth factor (NGF) protein were measured by enzymeâlinked immunosorbent assay. RESULTS: Mice developed painârelated behavior 8 weeks after undergoing partial meniscectomy or 12 weeks after undergoing DMM. NGF, bradykinin receptors B1 and B2, tachykinin, and tachykinin receptor 1 were significantly regulated in the joints of mice displaying painârelated behavior. Little regulation of inflammatory cytokines, leukocyte activation markers, or chemokines was observed. When tissue samples from articular cartilage, meniscus, and bone were analyzed separately, NGF was consistently regulated in the articular cartilage. The other pain sensitizers were also largely regulated in the articular cartilage, although there were some differences between the 2 models. NGF and tachykinin were strongly regulated by simple mechanical injury of cartilage in vitro in a transforming growth factor ÎČâactivated kinase 1â, fibroblast growth factor 2â, and Src kinaseâdependent manner. CONCLUSION: Damaged joint tissues produce proalgesic molecules, including NGF, in murine OA
Cilia protein IFT88 regulates extracellular protease activity by optimizing LRP-1âmediated endocytosis
Matrix protease activity is fundamental to developmental tissue patterning and remains influential in adult homeostasis. In cartilage, the principal matrix proteoglycan is aggrecan, the protease-mediated catabolism of which defines arthritis; however, the pathophysiologic mechanisms that drive aberrant aggrecanolytic activity remain unclear. Human ciliopathies exhibit altered matrix, which has been proposed to be the result of dysregulated hedgehog signaling that is tuned within the primary cilium. Here, we report that disruption of intraflagellar transport protein 88 (IFT88), a core ciliary trafficking protein, increases chondrocyte aggrecanase activity in vitro. We find that the receptor for protease endocytosis in chondrocytes, LDL receptorârelated protein 1 (LRP-1), is unevenly distributed over the cell membrane, often concentrated at the site of cilia assembly. Hypomorphic mutation of IFT88 disturbs this apparent hot spot for protease uptake, increases receptor shedding, and results in a reduced rate of protease clearance from the extracellular space. We propose that IFT88 and/or the cilium regulates the extracellular remodeling of matrixâindependently of Hedgehog regulationâby enabling rapid LRP-1âmediated endocytosis of proteases, potentially by supporting the creation of a ciliary pocket. This result highlights new roles for the ciliumâs machinery in matrix turnover and LRP-1 function, with potential relevance in a range of diseases.âCoveney, C. R., Collins, I., Mc Fie, M., Chanalaris, A., Yamamoto, K., Wann, A. K. T. Cilia protein IFT88 regulates extracellular protease activity by optimizing LRP-1âmediated endocytosis
Array CGH analysis at 60kb resolution of CML samples at advanced stage of disease
In spite of the universal presence of the BCR/ABL1 fusion gene, chronic myelogenous leukemia (CML) shows remarkable clinical and genetic diversity. The consequences of der(9)t(9;22) chromosome deletions, associated with poor survival, as well as the mechanism behind their formation remain unclear, as does our understanding of the molecular events driving the disease evolution. The presence of these deletions fuelled the expectations that cryptic genome-wide aberrations may be accountable for the disease progression. Following a comprehensive BAC aCGH analysis of 48 CML samples (Brazma et al., Genes, Chromosomes & Cancer, 2007 in press) we report high-resolution oligo-nucleotide array study of a further 30 CML accelerated/ blast phase samples. We were unable to confirm the high frequency of particular single BAC imbalances (CNVs), reported both by ourselves and others, possibly due to the manufacturerâs array selection strategy. Never-the-less some of the CNVs and a wealth of new imbalances were obtained at 60kb resolution. It was possible to build a precise map of the amplicon affecting the sequences flanking the 3' ABL1 breakpoint site, which include the LAMC3 and NUP214 genes. The presence of this amplicon was associated with therapy resistance. When assessed, at a resolution of 60 kb, the deletions of the regions flanking the ABL1/BCR breakpoint showed novel features:
1. the genome loss affects preferentially both flanking sites as seen in 5 of the 6 âdeletedâ samples and 2. the 120kb deletion identified is the smallest recorded so far. Most of the major cytogenetic features of the samples were confirmed and a number of cryptic genome imbalances were detected, from 120kb to 10Mb in size, involving regions rich in genes, some already implicated in the pathogenesis of CML. Finally, recurrent micro aberrations of several adjacent oligo-nucleotides affecting non-coding sequences were detected in as many as 2/3 of the samples
Mature primary human osteocytes in mini organotypic cultures secrete FGF23 and PTH1-34-regulated sclerostin
IntroductionFor decades, functional primary human osteocyte cultures have been crucially needed for understanding their role in bone anabolic processes and in endocrine phosphate regulation via the bone-kidney axis. Mature osteocyte proteins (sclerostin, DMP1, Phex and FGF23) play a key role in various systemic diseases and are targeted by successful bone anabolic drugs (anti-sclerostin antibody and teriparatide (PTH1-34)). However, cell lines available to study osteocytes produce very little sclerostin and low levels of mature osteocyte markers. We have developed a primary human 3D organotypic culture system that replicates the formation of mature osteocytes in bone.MethodsPrimary human osteoblasts were seeded in a fibrinogen / thrombin gel around 3D-printed hanging posts. Following contraction of the gel around the posts, cells were cultured in osteogenic media and conditioned media was collected for analysis of secreted markers of osteocyte formation.ResultsThe organoids were viable for at least 6 months, allowing co-culture with different cell types and testing of bone anabolic drugs. Bulk RNAseq data displayed the developing marker trajectory of ossification and human primary osteocyte formation in vitro over an initial 8- week period. Vitamin D3 supplementation increased mineralization and sclerostin secretion, while hypoxia and PTH1-34 modulated sclerostin. Our culture system also secreted FGF23, enabling the future development of a bone-kidney-parathyroid-vascular multi-organoid or organ-on-a-chip system to study disease processes and drug effects using purely human cells.DiscussionThis 3D organotypic culture system provides a stable, long-lived, and regulated population of mature human primary osteocytes for a variety of research applications