Search results for "alkaline phosphatase"
showing 10 items of 139 documents
Activation of Human Osteoblasts via Different Bovine Bone Substitute Materials With and Without Injectable Platelet Rich Fibrin in vitro
2021
IntroductionThe aim of the in vitro study was to compare the effect of four bovine bone substitute materials (XBSM) with and without injectable platelet-reach fibrin for viability and metabolic activity of human osteoblasts (HOB) as well as expression of alkaline phosphatase (ALP), bone morphogenetic protein 2 (BMP-2), and osteonectin (OCN).Materials and MethodsCerabone® (CB), Bio-Oss® (BO), Creos Xenogain® (CX) and MinerOss® X (MO) ± i-PRF were incubated with HOB. At day 3, 7, and 10, cell viability and metabolic activity as well as expression of ALP, OCN, and BMP-2, was examined.ResultsFor non-i-PRF groups, the highest values concerning viability were seen for CB at all time points. Pre-t…
Depletion of alphaV integrins from osteosarcoma cells by intracellular antibody expression induces bone differentiation marker genes and suppresses g…
1999
Integrin heterodimers sharing the common alphaV subunit are receptors for adhesion glycoproteins such as vitronectin and fibronectin. They are suggested to play an essential role in cell anchoring, differentiation, and survival. Here, we describe the construction of an expression plasmid coding for an intracellular single-chain antibody against alphaV integrin subunit. Saos-2 osteosarcoma cells transfected with this DNA construct showed an approximately 70-100% decrease in the cell surface expression of alphaVbeta3 and alphaVbeta5 integrins as shown by flow cytometry. Intracellular antibody expression had no effect on the mRNA levels of alphaV integrin. Pulse chase experiments of metabolica…
Alkaline Phosphatase: Keeping the Peace at the Gut Epithelial Surface
2007
Vertebrates harbor abundant lipopolysaccharide (LPS) or endotoxin in their gut microbiota. Here we demonstrate that the brush border enzyme intestinal alkaline phosphatase (Iap), which dephosphorylates LPS, is induced during establishment of the microbiota and plays a crucial role in promoting mucosal tolerance to gut bacteria in zebrafish. We demonstrate that Iap deficient animals are hypersensitive to LPS toxicity through a mechanism mediated by Myd88 and Tumor Necrosis Factor Receptor (Tnfr). We further show that the endogenous microbiota establish the normal homeostatic level of neutrophils in the intestine through a process involving Myd88 and Tnfr. Iap deficient animals exhibit excess…
Phosphate Groups in the Lipid A Moiety Determine the Effects of LPS on Hepatic Stellate Cells: A Role for LPS-Dephosphorylating Activity in Liver Fib…
2020
Alkaline phosphatase (AP) activity is highly upregulated in plasma during liver diseases. Previously, we demonstrated that AP is able to detoxify lipopolysaccharide (LPS) by dephosphorylating its lipid A moiety. Because a role of gut-derived LPS in liver fibrogenesis has become evident, we now examined the relevance of phosphate groups in the lipid A moiety in this process. The effects of mono-phosphoryl and di-phosphoryl lipid A (MPLA and DPLA, respectively) were studied in vitro and LPS-dephosphorylating activity was studied in normal and fibrotic mouse and human livers. The effects of intestinal AP were studied in mice with CCL4-induced liver fibrosis. DPLA strongly stimulated fibrogenic…
Gallium modulates osteoclastic bone resorption in vitro without affecting osteoblasts.
2010
Gallium (Ga) has been shown to be effective in the treatment of disorders associated with accelerated bone loss, including cancer-related hypercalcemia and Paget's disease. These clinical applications suggest that Ga could reduce bone resorption. However, few studies have studied the effects of Ga on osteoclastic resorption. Here, we have explored the effects of Ga on bone cells in vitro.In different osteoclastic models [osteoclasts isolated from long bones of neonatal rabbits (RBC), murine RAW 264.7 cells and human CD14-positive cells], we have performed resorption activity tests, staining for tartrate resistant acid phosphatase (TRAP), real-time polymerase chain reaction analysis, viabili…
Enzyme histochemical and immunohistochemical characterization of oval and parenchymal cells proliferating in livers of rats fed a choline-deficient/D…
1991
Male outbred Sprague-Dawley rats were fed a choline-deficient diet containing 0.10% DL-ethionine for up to 30 weeks. Liver slices from rats killed 4, 6, 10, 14, 22 and 30 weeks after starting the treatment were histochemically analyzed for the following parameters: basophilia, expression of cytokeratin 19 (which in the liver is bile duct epithelial cell-specific), glycogen content and activities of glycogen synthetase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphatase (G6PASE), glucose-6-phosphate dehydrogenase (G6PDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glycerin-3-phosphate dehydrogenase (G3PDH), 'malic enzyme' (MDH), alkaline phosphatase (ALKPASE) and gamma-glutamyl…
Isolation, biochemical characterization, long-term culture, and phenotype modulation of oval cells from carcinogen-fed rats.
1993
Oval cells are liver epithelial cells that proliferate during hepatocarcinogenesis and chemically induced severe liver injury. It has been suggested that these cells represent hepatic stem cells which might play an important role in the histogenesis of cholangiocellular as well as hepatocellular carcinomas. In order to test this hypothesis highly purified oval cell preparations and propagable oval cell lines are needed. In the present study the isolation, biochemical characterization, and long-term culture of oval cells from rats fed a choline-deficient/DL-ethionine-supplemented diet for 6, 14, or 22 weeks are described. The freshly isolated oval cells were gamma-glutamyltranspeptidase-posi…
A novel rat model of chronic fibrosing cholangitis induced by local administration of a hapten reagent into the dilated bile duct is associated with …
2000
Abstract Background/Aim: The cholangiopathies represent hepatobiliary diseases in which bile-duct epithelial cells are targets for destructive processes, including immune-mediated damage. We describe a novel rat model of chronic fibrosing cholangitis induced by administration of the hapten reagent 2,4,6-trinitrobenzenesulfonic acid (TNBS) into the dilated bile duct. Methods: The common bile duct was dilated due to a mild stenosis in 8-week-old female Lewis rats. TNBS (50 mg/kg) was injected during a second laparotomy. Results: TNBS-treatment reproducibly resulted in chronic fibrosing cholangitis. In retrograde cholangiography the bile ducts showed irregularities, beading and strictures. Alk…
Periodontal and biochemical bone metabolism assessment on a chronic oral anticoagulation population treated with dicoumarins
2016
Background The aim is to evaluate periodontal alteration and biochemical markers associated with bone turnover in chronic oral with dicoumarins anticoagulant treatment patients. Material and Methods 80 patients treated with oral anticoagulants were divided into 2 cohort: Group A (n=36) 6 month to 1 year with anticoagulant treatment and Group B (n=44) > 2 years with anticoagulant treatment. Clinical evaluation included: Clinical attachment level (CAL), plaque index (PI) and gingival index (GI). Analytically biochemical parameters of bone remodeling (calcium and phosphorus), formation (total acid phosphatase, alkaline phosphatase and osteocalcin) and resorption (tartrate-resistant acid phosph…
Characteristics of lysosomal phosphomannosyl-enzyme receptors in the rat heart
1987
The receptor system recognizing mannose 6-phosphate groups of lysosomal enzymes has been characterized, e.g. in fibroblasts and liver cells. The purpose of this study was to demonstrate the presence of a phosphomannosyl receptor system in rat heart muscle. The characterization of receptors was accomplished with beta-N-acetylglucosaminidase (beta-GA) secreted by rat embryo fibroblasts after ammonium chloride stimulation. The receptor binding of ligand enzymes was saturated by adding increasing concentrations of beta-GA and the binding increased linearly when the content of membrane protein was increased. The binding of beta-GA was inhibited by mannose and glucose phosphates, especially manno…