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Di Marco E Sessarego N Zerega B Cancedda R Cancedda FD 《Journal of cellular physiology》2003,196(3):464-473
Ex-FABP, an extracellular fatty acid binding lipocalin, is physiologically expressed by differentiating chicken chondrocytes and myoblasts. Its expression is enhanced after cell treatment with inflammatory stimuli and repressed by anti-inflammatory agents, behaving as an acute phase protein. Chicken liver fragments in culture show enhanced protein expression after bacterial endotoxin treatment. To investigate the biological role of Ex-FABP, we stably transfected proliferating chondrocytes with an expression vector carrying antisense oriented Ex-FABP cDNA. We observed a dramatic loss of cell viability and a strong inhibition of cell proliferation and differentiation. When chondrocytes were transfected with the antisense oriented Ex-FABP cDNA we observed that Ex-FABP down-modulation increased apoptotic cell number. Myoblasts transfected with the same expression vector showed extensive cell death and impaired myotube formation. We suggest that Ex-FABP acts as a constitutive survival protein and that its expression and activation are fundamental to protect chondrocytes from cell death. 相似文献
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Cermelli S Zerega B Carlevaro M Gentili C Thorp B Farquharson C Cancedda R Cancedda FD 《European journal of cell biology》2000,79(3):155-164
Ex-FABP, extracellular fatty acid binding protein, is a 21 kDa lipocalin expressed in hypertrophic cartilage, muscle and heart during chick embryo development and in granulocytes. Ex-FABP synthesis was increased in chondrocyte and myoblast cultures by inflammatory agents (LPS; IL6) and repressed by antiinflammatory agents. Expression of Ex-FABP and specific gelatinases is paralleled in hypertrophic cartilage; LPS specifically induced high molecular weight gelatinase ( > 200 kDa). LPS-treated hypertrophic chondrocytes showed increased chemotactic activity for endothelial cells paralleled by increased expression of transferrin. A high amount of Ex-FABP was expressed in adult pathological cartilage both in dyschondroplastic and osteoarthritic chickens. Controls were negative. Ex-FABP could represent a stress protein physiologically expressed in tissues where active remodelling is taking place during development and in tissues characterized by an acute phase response due to pathological conditions. We also suggest that during endochondral bone formation other responses characteristic of a local inflammatory status, such as gelatinase production and angiogenic factor secretion, are "physiologically" activated. 相似文献
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Ex-FABP: a fatty acid binding lipocalin developmentally regulated in chicken endochondral bone formation and myogenesis 总被引:2,自引:0,他引:2
Descalzi Cancedda F Dozin B Zerega B Cermelli S Cancedda R 《Biochimica et biophysica acta》2000,1482(1-2):127-135
Extracellular fatty acid binding protein (Ex-FABP) is a 21 kDa lipocalin specifically binding fatty acids, expressed during chicken embryo development in hypertrophic cartilage, in muscle fibers and in blood granulocytes. In chondrocyte and myoblast cultures Ex-FABP expression is increased by inflammatory agents and repressed by anti-inflammatory agents. In adult cartilage Ex-FABP is expressed only in pathological conditions such as in dyschondroplastic and osteoarthritic chickens. The possible mammalian counterpart is the Neu-related lipocalin (NRL), a lipocalin overexpressed in rat mammary cancer; NRL is homologous to the human neutrophil gelatinase associated lipocalin (NGAL) expressed in granulocytes and in epithelial cells in inflammation and malignancy and to the Sip24 (super-inducible protein 24), an acute phase lipocalin expressed in mouse after turpentine injection. Immunolocalization and in situ hybridization showed that NRL/NGAL is expressed in hypertrophic cartilage, in forming skeletal muscle fibers and in developing heart. In adult cartilage NRL/NGAL was expressed in articular cartilage from osteoarthritic patients and in chondrosarcoma. Moreover, NRL was induced in chondrocyte and myoblast cultures by an inflammatory agent. We propose that these lipocalins (Ex-FABP, NRL/NGAL, Sip24) represent stress proteins physiologically expressed in tissues where active remodeling is taking place during development and also present in tissues characterized by an acute phase response due to pathological conditions. 相似文献
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Cell death pathways have evolved to maintain tissue homoeostasis and eliminate potentially harmful cells from within an organism, such as cells with damaged DNA that could lead to cancer. Apoptosis, known to eliminate cells in a predominantly non-inflammatory manner, is controlled by two main branches, the intrinsic and extrinsic apoptotic pathways. While the intrinsic pathway is regulated by the Bcl-2 family members, the extrinsic pathway is controlled by the Death receptors, members of the tumour necrosis factor (TNF) receptor superfamily. Death receptors can also activate a pro-inflammatory type of cell death, necroptosis, when Caspase-8 is inhibited. Apoptotic pathways are known to be tightly regulated by post-translational modifications, especially by ubiquitination. This review discusses research on ubiquitination-mediated regulation of apoptotic signalling. Additionally, the emerging importance of ubiquitination in regulating necroptosis is discussed.Subject terms: Protein-protein interaction networks, Deubiquitylating enzymes, Ubiquitin ligases, Ubiquitylation 相似文献
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Breadfruit (Artocarpus altilis, Moraceae), a traditional starch crop in Oceania, has enjoyed legendary status ever since its role in the infamous mutiny aboard the H.M.S. Bounty in 1789, yet its origins remain unclear. Breadfruit's closest relatives are A. camansi and A. mariannensis. DNA fingerprinting data (AFLP, amplified fragment length polymorphisms) from over 200 breadfruit cultivars, 30 A. camansi, and 24 A. mariannensis individuals were used to investigate the relationships among these species. Multivariate analyses and the identification of species-specific AFLP markers indicate at least two origins of breadfruit. Most Melanesian and Polynesian cultivars appear to have arisen over generations of vegetative propagation and selection from A. camansi. In contrast, most Micronesian breadfruit cultivars appear to be the result of hybridization between A. camansi-derived breadfruit and A. mariannensis. Because breadfruit depends on humans for dispersal, the data were compared to theories on the human colonization of Oceania. The results agree with the well-supported theory that humans settled Polynesia via Melanesia. Additionally, a long-distance migration from eastern Melanesia into Micronesia is supported. 相似文献
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Higham T Basell L Jacobi R Wood R Ramsey CB Conard NJ 《Journal of human evolution》2012,62(6):664-676
The German site of Geißenklösterle is crucial to debates concerning the European Middle to Upper Palaeolithic transition and the origins of the Aurignacian in Europe. Previous dates from the site are central to an important hypothesis, the Kulturpumpe model, which posits that the Swabian Jura was an area where crucial behavioural developments took place and then spread to other parts of Europe. The previous chronology (critical to the model), is based mainly on radiocarbon dating, but remains poorly constrained due to the dating resolution and the variability of dates. The cause of these problems is disputed, but two principal explanations have been proposed: a) larger than expected variations in the production of atmospheric radiocarbon, and b) taphonomic influences in the site mixing the bones that were dated into different parts of the site. We reinvestigate the chronology using a new series of radiocarbon determinations obtained from the Mousterian, Aurignacian and Gravettian levels. The results strongly imply that the previous dates were affected by insufficient decontamination of the bone collagen prior to dating. Using an ultrafiltration protocol the chronometric picture becomes much clearer. Comparison of the results against other recently dated sites in other parts of Europe suggests the Early Aurignacian levels are earlier than other sites in the south of France and Italy, but not as early as recently dated sites which suggest a pre-Aurignacian dispersal of modern humans to Italy by ∼45000 cal BP. They are consistent with the importance of the Danube Corridor as a key route for the movement of people and ideas. The new dates fail to refute the Kulturpumpe model and suggest that Swabian Jura is a region that contributed significantly to the evolution of symbolic behaviour as indicated by early evidence for figurative art, music and mythical imagery. 相似文献