Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine the relationship between the expression of bone proteins and the formation of mineralized-tissue matrix, the biosynthesis of non-collagenous bone proteins was studied in cultures of fetal-rat calvarial cells, which form mineralized nodules of bone-like tissue in the presence of beta-glycerophosphate. The temporal pattern of protein synthesis in both mineralizing and non-mineralizing cultures was studied by metabolic labelling with [35S]methionine, 35SO4(2-) or 32PO4(3-) over a 5-day period. After a 24 h labelling period, the culture media were harvested and the cell layers extracted sequentially with aq. 0.5 M-NH3, followed by 4 M-guanidinium chloride (GdmCl), 0.5 M-EDTA and a second extraction with 4 M-GdmCl. Protein associated with collagenous bone matrix was analysed after digestion with bacterial collagenase. On the basis of [35S]methionine labelling, the major proteins extracted from the mineralizing matrix were secreted phosphoprotein-1 (SPP-1; osteopontin), bone sialoprotein (BSP) and a 14 kDa phosphoprotein. The presence of SPP-1 and BSP in the conditioned media of both mineralizing and non-mineralizing cultures and their incorporation into the mineralizing nodules indicated that these proteins associate with preformed mineral crystals. However, some BSP was also present in GdmCl extracts and, together with a 35 kDa sulphated protein, was released from a bacterial-collagenase digestion of the tissue residue in both non-mineralizing and mineralizing cultures. Two forms of sulphated SPP-1 were identified, a highly phosphorylated 44 kDa species being the predominant form in the mineralized matrix. The BSP was more highly sulphated but less phosphorylated than SPP-1. Bone SPARC (secreted protein, acid and rich in cysteine) protein (osteonectin) was present almost entirely in the conditioned media and did not incorporate 32PO4(3-) or 35SO4(2-). The SPP-1 and the 14 kDa protein were susceptible to thrombin digestion, the 44 kDa SPP-1 being specifically cleaved into 28 and 26 kDa fragments. The fragments were labelled uniformly with [35S]methionine, but the 28 kDa fragment incorporated more 35SO4(2-), but less 32PO4(3-), than the 26 kDa fragment. These studies demonstrate that SPP-1 and BSP are the major osteoblast-derived bone proteins to bind to the bone mineral. That BSP also binds to the collagenous bone matrix indicates a potential role for this protein in linking the hydroxyapatite with collagen.
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PMID:Biosynthesis of bone proteins [SPP-1 (secreted phosphoprotein-1, osteopontin), BSP (bone sialoprotein) and SPARC (osteonectin)] in association with mineralized-tissue formation by fetal-rat calvarial cells in culture. 200 15

The nature and tissue distribution of non-collagenous bone proteins synthesized by adult rat bone marrow cells, induced to differentiate in the presence of dexamethasone (DEX) and beta-glycerophosphate (beta-GP), was studied in vitro to determine the potential role of these proteins in bone formation. Northern hybridization analysis revealed a strong induction of bone sialoprotein (BSP) and osteocalcin in DEX-treated cultures, whereas the constitutive expression of secreted phosphoprotein I (SPP-1), type I collagen, SPARC, and alkaline phosphatase was stimulated 6-, 5-, 3-, and 2.5-told, respectively. Metabolic labeling of proteins showed that the sialoproteins (SPP-1 and BSP) were mostly secreted into the culture medium in the non-mineralizing (-beta-GP) cultures, but were the predominant non-collagenous proteins associated with the hydroxyapatite of the bone nodules in mineralizing cultures (+ beta-GP). Extraction of the tissue matrix with 4 M GuHCl and digestion of the demineralized tissue matrix with bacterial collagenase revealed that some BSP was also associated non-covalently and covalently with the collagenous matrix. SPP-1 was present in two distinct, 44 kDa and 55 kDa, forms in the conditioned medium of all cultures and was preferentially associated with the hydroxyapatite in the mineralizing cultures. In comparison, SPARC was abundant in culture media but could not be detected in de-mineralizing extracts of the mineralized tissue. Radiolabeling with [35SO4] demonstrated that both SPP-1 and BSP synthesized by bone cells are sulfated, and that a 35 kDa protein and some proteoglycan were covalently associated with the collagenous matrix in +DEX cultures. Labeling with [32PO4] was essentially confined to the sialoproteins; the 44 kDa SPP-1 incorporating significantly more [32PO4] than the 55 kDa SPP-1 and the BSP. These studies demonstrate that BSP and osteocalcin are only expressed in differentiated osteoblasts and that most of the major non-collagenous bone proteins associate with the bone mineral. However, some novel proteins together with some of the BSP are associated with the collagenous matrix where they can influence hydroxyapatite formation.
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PMID:Expression of bone matrix proteins associated with mineralized tissue formation by adult rat bone marrow cells in vitro: inductive effects of dexamethasone on the osteoblastic phenotype. 203 18

An important objective in nowadays research is the discovery of new biomarkers that can detect colon tumours in early stages and indicate with accuracy the status of the disease. The aim of our study was to identify potential biomarkers for colon cancer onset and progression. We assessed gene expression profiles of a list of 10 candidate genes (MMP-1, MMP-3, MMP-7, DEFA 1, DEFA-5, DEFA-6, IL-8, CXCL-1, SPP-1, CTHRC-1) by quantitative real time PCR in triplets of colonic mucosa (normal, adenoma, tumoral tissue) collected from the same patient during surgery for a group of 20 patients. Additionally we performed immunohistochemistry for DEFA1-3 and SPP1. We remarked that DEFA5 and DEFA6 are key factors in adenoma formation (p<0.05). MMP7 is important in the transition from a benign to a malignant status (p <0.01) and further in metastasis being a prognostic indicator for tumor transformation and for the metastatic potential of cancer cells. IL8, irrespective of tumor stage, has a high mRNA level in adenocarcinoma (p< 0.05). The level of expression for SPP1 is correlated with tumor level. We suggest that high levels of DEFAS, DEFA6 (key elements in adenoma formation), MMP7 (marker of colon cancer onset and progression to metastasis), SPP1 (marker of progression) and IL8 could be used to diagnose an early stage colon cancer and to evaluate the prognostic of progression for colon tumors. Further, if DEFA5 and DEFA6 level of expression are low but MMP7, SPP1 and IL8 level are high we could point out that the transition from adenoma to adenocarcinoma had already occurred. Thus, DEFA5, DEFA6, MMP7, IL8 and SPP1 consist in a valuable panel of biomarkers, whose detection can be used in early detection and progressive disease and also in prognostic of colon cancer.
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PMID:Prognostic and predictive potential molecular biomarkers in colon cancer. 2169 62