Transglutaminases (TGs) stabilize proteins by the formation of ε(γ-glutamyl)lysine cross-links. Here, we demonstrate that the cross-linking of collagen I (COL I) by tissue transglutaminase (TG2) causes an alteration in the morphology and rheological properties of the collagen fibers. Human osteoblasts (HOB) attach, spread, proliferate, differentiate and mineralize more rapidly on this cross-linked matrix compared to native collagen.
View Article and Find Full Text PDFBackground: Epithelial ovarian cancer (EOC) constitutes more than 90% of ovarian cancers and is associated with high mortality. EOC comprises a heterogeneous group of tumours, and the causes and molecular pathology are essentially unknown. Improved insight into the molecular characteristics of the different subgroups of EOC is urgently needed, and should eventually lead to earlier diagnosis as well as more individualized and effective treatments.
View Article and Find Full Text PDFPeriostin is a 90 kDa secreted protein, originally identified in murine osteoblast-like cells, with a distribution restricted to collagen-rich tissues and certain tumors. In this paper, we first analyzed the expression of periostin mRNA and protein in human fetal osteoblasts (hFOB) and human osteosarcoma (hOS) cell lines by RT real-time PCR and Western blot, respectively. The hFOB 1.
View Article and Find Full Text PDFThe Ca(2+)/Calmodulin-dependent protein kinase (CaMK) family is activated in response to elevation of intracellular Ca(2+), and includes CaMK1 (as well as CaMK2 and CaMK4), which exists as different isoforms (alpha, beta, gamma and delta). CaMK1 is present in several cell types and may be involved in various cellular processes, but its role in bone is unknown. In situ hybridization was used to determine the spatial and temporal expression of CaMK1beta during endochondral bone development in mouse embryos and newborn pups.
View Article and Find Full Text PDFThe transcription factor Sox4 is vital for fetal development, as Sox4(-/-) homozygotes die in utero. Sox4 mRNA is expressed in the early embryonic growth plate and is regulated by parathyroid hormone, but its function in bone modeling/remodeling is unknown. We report that Sox4(+/-) mice exhibit significantly lower bone mass (by dual-energy X-ray absorptiometry) from an early age, and fail to obtain the peak bone mass of wild-type (WT) animals.
View Article and Find Full Text PDFThe human estrogen receptor alpha (ERalpha) gene is driven by multiple promoters, of which the F promoter alone is found to be active in primary osteoblasts. The study was aimed at identifying new regulatory pathways affecting transcription of the receptor in this cell lineage. We generated human osteoblast-like cells, Saos-2, stably transfected with a luciferase-reporter gene downstream of the human ERalpha F promoter (Saos F-Luc), and assayed the reporter response to differentiation-related signals.
View Article and Find Full Text PDFc-Src is a proto-oncogene, belonging to the nonreceptor protein kinases family, which plays a prominent role in carcinogenesis. In this study, we tested the hypothesis that c-Src could promote breast cancer metastasis acting on several cell types and that pharmacological disruption of its kinase activity could be beneficial for the treatment of metastases. Female BALB/c-nu/nu mice were subjected to intracardiac injection of the human breast cancer cells MDA-MB-231 (MDA-231), which induced prominent bone and visceral metastases.
View Article and Find Full Text PDFUnlabelled: Celiac disease is an autoimmune disorder characterized by atrophy of the intestine villi triggered by ingestion of gluten in genetically susceptible individuals. The association between celiac disease and low BMD has been recognized, but the mechanisms of disturbance are poorly understood. We show imbalance of cytokines relevant to bone metabolism in celiac patients' sera and the direct effect of these sera on in vitro bone cell activity.
View Article and Find Full Text PDFIt has been previously reported that the abundance and distribution of transposable elements (TEs) in Drosophila heterochromatin are conserved in unrelated stocks although they may greatly differ between families. The biases in genomic distribution of TEs are potentially informative for understanding host-transposon interactions. Here we report that in most stocks, one to four elements of the 1731 retrotransposon family are located on the Y chromosome within regions that appear to be polytenized in larval salivary glands.
View Article and Find Full Text PDFA follow-up over 83 generations has been carried out, by the Southern blotting technique, of a Drosophila stock which is unstable in the location of Bari 1 elements. The persistent intrastock polymorphism detected is largely amenable to insertion/excision equilibria at 36 genomic sites that form a gradient in occupancy. In a closely related stock, Bari 1 elements are stable and exhibit a substantially different genomic distribution.
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