Osteopontin (OPN) is a secreted phosphoprotein that is constitutively expressed in the normal kidney and is induced by various experimental and pathologic conditions. Several possible functions of OPN have been suggested, however the mechanism and significance of OPN expression are still uncertain. Since high salt concentration or salt crystal have been known to enhance OPN expression in intact kidney or cultured renal cells, in the present study we examined whether or not a low salt condition had an effect on OPN expression in the kidney. Adult male Sprague-Dawley rats were fed either a normal sodium or a sodium deficient diet for 1 week. Kidneys were processed for in situ hybridization using a digoxigenin-labeled riboprobe and for immunohistochemistry using antibodies to OPN, renin, and Na-K-ATPase. In rats fed a normal sodium diet, OPN mRNA and protein were expressed only in the descending thin limbs of Henle's loop (DTL) and in the papillary and pelvic surface epithelium (PSE). In rats fed a sodium deficient diet, there was a marked decrease in OPN immunoreactivity in the DTL, but no changes in PSE. In contrast, no changes were observed in OPN mRNA expression in the DTL by in situ hybridization, indicating that decreased OPN protein expression was a result of translational regulation. As expected, rats fed a sodium deficient diet were associated with increased immunoreactivity for Na-K-ATPase and renin compatible with activation of the renin-angiotensin system. These results suggest that dietary sodium may be involved in the regulation of OPN expression in the DTL of the rat kidney.
Animal ; Diet, Sodium-Restricted* ; Immunohistochemistry ; In Situ Hybridization ; Kidney/metabolism* ; Male ; Na(+)-K(+)-Exchanging ATPase/metabolism ; Rats ; Rats, Sprague-Dawley ; Renin/metabolism ; Sialoglycoproteins/metabolism ; Sialoglycoproteins/antagonists & inhibitors* ; Sodium/deficiency*

Advanced atherosclerosis is often associated with dystrophic calcification and remodeling of extracellular matrix of vascular wall. Recently many studies have documented a general relationship between calcification and severity of coronary disease, and discussed the feasibility of electron beam computed tomography for detecting and quantifying the coronary artery calcification in the patients. The present study investigated the expression and the localization of osteopontin, one of noncollagenous bone matrix protein, within the calcified coronary arteries. Autopsy-derived coronary artery specimens were scanned and reconstructed to visualize the pattern of coronary calcification using a novel microscopic computed tomography technique. The localization of the osteopontin were evaluated by immunohistochemial stain with LF7. The present study showed that the pattern of coronary calcification is variable and the expression of osteopontin is localized mainly to calcified lesion. The smooth muscle cells in addition to macrophage expressed osteopontin protein in human coronary atherosclerotic plaques. Soluble osteopontin released near to the sites of vascular calcification may represent an adaptive mechanism aimed at regulating the process of vascular calcification.
Aged ; Calcinosis/metabolism ; Coronary Arteriosclerosis/pathology* ; Coronary Arteriosclerosis/metabolism* ; Coronary Vessels/pathology* ; Coronary Vessels/metabolism ; Coronary Vessels/chemistry* ; Female ; Human ; Immunohistochemistry ; Male ; Middle Age ; Sialoglycoproteins/biosynthesis ; Sialoglycoproteins/analysis*

OBJECTIVETo investigate the osteoblast-like functional characteristics exhibited by human periodontal ligament cells (hPDLCs) under mechanical force.

METHODSHuman PDLCs cultured in vitro were stretched by mechanical force. Radioimmunoassay (RIA) was used to measure the expression of secreting alkaline phosphotase (ALP) and osteocalcin (OCN). The non-secreting ALP, OCN and osteopontin (OPN) in cells were determined by immunohistochemistry.

RESULTSIt exhibited increasing of ALP secreted into conditional media, and in the 24 hour period there were two peaks which appeared at the 2nd and 4th hour and the 24th hour (P < 0.01). While in the late of the 24 hours, expression of OCN in conditional media increased (P < 0.05).

CONCLUSIONMechanical force induces hPDLCs to differentiate into functional osteoblast-like cells and plays a role in bone remodeling.

Alkaline Phosphatase ; metabolism ; Cells, Cultured ; Humans ; Osteocalcin ; analysis ; Osteoclasts ; physiology ; Osteopontin ; Periodontal Ligament ; cytology ; Sialoglycoproteins ; analysis ; Stress, Mechanical

Sialic acid residues are constant constituents of the glycoproteins of the airways in all species. Sialoglycoproteins are the main acidic glycoprotein and their functions are to mediate cell adherence, to control the viscoelasticity of mucus and to serve as receptor sites for the binding of exogenous macromolecules. The purpose of this study was to investigate the differences in the distribution of sialoglycoproteins as a terminal sugar and in the composition of the penultimate sugar according to aging in the murine nasal respiratory and olfactory mucosa. Nasal cavities of mice (BALB/c) were fixed by intracardiac perfusion with 2.0% glutaraldehyde and embedded in Epon 812. First, the serial sections were stained with Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA). Then, the adjacent sections were stained with DBA and PNA before and after neuraminidase digestion in all experimental groups. Apical cell surfaces of olfactory mucosa and cilia on a few ciliated cells in the mucosa of the septum and nasal floor were labelled with MAA, but cell surfaces of respiratory mucosa, Bowman's glands and goblet cells were not labelled with MAA, irrespective of aging. Apical cell surfaces of both olfactory and respiratory mucosa and Bowman's glands were stained with SNA, however, goblet cells were not labelled with SNA. After neuraminidase digestion to remove terminal sialic acid residues of sialoglycoproteins, only cell surfaces of respiratory mucosa were labelled with PNA, but goblet cells, cell surfaces of olfactory mucosa and Bowman's glands were not labelled with PNA. Cell surfaces and Bowman's glands of olfactory mucosa were labelled with DBA after neuraminidase digestion, but cell surfaces of respiratory mucosa and goblet cells were not labelled with DBA. Our results indicate that there were different carbohydrate structures of sialoglycoconjugates in olfactory and respiratory mucosa, and it was not influenced by aging.
Aging/metabolism* ; Animal ; Carbohydrates/analysis* ; Mice ; Mice, Inbred BALB C ; Nasal Mucosa/chemistry* ; Olfactory Mucosa/chemistry* ; Sialoglycoproteins/analysis*

OBJECTIVETo investigate the correlation between expression of the osteopontin (OPN) and invasion and metastases in gastric cancer.

METHODSThe expression of OPN, NF-kappaB p65 and matrix metallo-proteinase 9 (MMP-9) was detected by immunohistochemistry in non-cancer gastric tissue (n = 12 cases) and gastric cancer tissue (n = 72 cases).

RESULTS(1) OPN, NF-kappaB p65 and MMP-9 were not expressed in 12 non-cancer gastric tissue samples(group A). Their expression rates were 43.3%, 40.0% and 46.7% respectively in 30 gastric cancer samples without lymph nodes metastasis (group B), but they increased to 76.9%, 73.1% and 80.8% in 26 gastric cancer samples with lymph nodes metastases (group C), and 87.5%, 81.3% and 93.8% respectively in 16 gastric cancer samples with lymph node and distant metastases (group D). (2) There were statistically significant differences in their expressions between group D and group B (P(a) = 0.004, P(c) = 0.007, P(e) = 0.002), and between group C and group B (P(b) = 0.011, P(d) = 0.013, P(f) = 0.009). (3) Despite some differences in positive expression rates, correlations existed between OPN and NF-kappaB p65, and between NF-kappaB p65 and MMP-9 (P(1) = 0.042, P(2) = 0.013; r(1)= 0.67, r(2)= 0.72).

CONCLUSIONOsteopondin espression is closely related to the invasion and metastases of gastric cancer. It may upregulate the expression of metastasis-related molecule MMP-9 by activating NF-kappaB pathway.

Female ; Humans ; Lymph Nodes ; pathology ; Lymphatic Metastasis ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Middle Aged ; Neoplasm Metastasis ; Osteopontin ; Sialoglycoproteins ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; Transcription Factor RelA ; metabolism

To investigate the pattern of expression of osteopontin (OPN) in tissues of the central nervous system (CNS) responding to peripheral immunological stimulation, the expression of OPN was studied in the spinal cord of rats with experimental autoimmune neuritis (EAN). In this model system, the sciatic nerves and spinal nerve roots are the target organs of EAN and the spinal cord is a remote organ that may be indirectly affected. OPN was constitutively expressed in some astrocytes adjacent to the pia mater and neurons in normal rats. In rats with EAN, OPN was increased in the same cells and in some inflammatory cells, including macrophages in the subarachnoid space. Expression of CD44, a receptor of OPN, was weak in normal spinal cord tissue and increased in the entire spinal cord parenchyma in rats with EAN, as well as in inflammatory cells. These findings suggest that inflammatory cells as well as reactive astrocytes are major sources of OPN and CD44 in the spinal cord of rats with EAN. Further study is needed to elucidate the functional role of OPN in the spinal cord affected by EAN.
Animals ; Antigens, CD44/metabolism ; Astrocytes/metabolism ; Ectodysplasins ; Female ; Immunohistochemistry ; Macrophages/metabolism ; Membrane Proteins ; Neuritis, Autoimmune, Experimental/*metabolism ; Neuroglia/metabolism ; Neurons/metabolism ; Osteopontin ; Rats ; Rats, Inbred Lew ; Sciatic Nerve/metabolism ; Sialoglycoproteins/*metabolism ; Spinal Cord/*metabolism ; Spinal Nerve Roots/metabolism

OBJECTIVETo evaluate the expression of dentin sialophosphoprotein (DSPP) in transfected rat bone marrow mesenchymal stem cells (BM-MSC) and the influence of the transfection.

METHODSPlasmid containing mice dentin DSPP was constructed by using the cytomegalovirus (CMV) promoter and then transfected the cultured BM-MSC by lipofectamine; The expression of Pax-9 and dentin matrix protein 1 (DMP1) gene of transfected BM-MSC were detected by RT-PCR. The expression of DSPP was examined by immunocytochemical staining, and the formation ratio of mineralized nodules of transfected BM-MSC was compared with untransfected ones after mineralized induction.

RESULTSThe constructed pcDNA3.1(+)/mDSPP could produced 3.0 kb and 5.4 kb fragments, DSPP gene and Pax9 gene were expressed 24 h and 48 h respectively, after BM-MSC were transfected Pax-9 gene was exprssed, but DMP1 gene was not; Immunohistochemical staining showed that DSPP was positive in transfected BM-MSC; The formation ratio of mineralized nodules of transfected BM-MSC was higher than that of untransfected ones after mineralized induction.

CONCLUSIONSThe expression of mice DSPP in BM-MSC by gene transfection can induce the expression of tooth development-associated gene Pax9 and enhance the formation of mineralized nodules, which suggests that DSPP gene might induce odontogenic differentiation of BM-MSC.

Animals ; Bone Marrow Cells ; metabolism ; Cells, Cultured ; Extracellular Matrix Proteins ; Genetic Vectors ; Mesenchymal Stromal Cells ; metabolism ; Mice ; Phosphoproteins ; Protein Precursors ; genetics ; Rats ; Sialoglycoproteins ; Transfection

To estimate intracellular interleukin-1 receptor antagonist (icIL-1ra) expression in the bone marrow cells from adult patients with chronic myelogenous leukemia (CML), flow cytometry (FCM) assay was used for detecting the mean icIL-1ra fluorescence intensity per cell (equivalent to it's expression level) in different groups of cells from normal and CML patient bone marrows by 15 monoclonal antibodies with different fluorescent marker. The results showed that all of marrow nucleated cells express IL-1ra, but its expression level in granulocytes was the highest and that in lymphocytes was the lowest. The icIL-1ra expression level was significantly lower in nucleated marrow cells, granulocytes and lymphocytes from the marrow of 17 untreated CML patients than that from the marrow of 8 normal. The mean icIL-1ra fluorescence intensity was significantly lower in marrow nucleated cells, granulocytes and lymphocytes in 13 CML patients with marrow blasts >or= 10% than that in 43 CML patients with marrow blasts < 5% or than that in 9 CML patients with marrow blasts 5% - 10%. It was concluded that the lower expression of icIL-1ra in CML marrow nucleated cells might be involved in the evolution of CML.
Adult ; Bone Marrow Cells ; metabolism ; Flow Cytometry ; Humans ; Interleukin 1 Receptor Antagonist Protein ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; metabolism ; pathology ; Sialoglycoproteins ; biosynthesis ; blood

This study was aimed to investigate the function defect of partial homing receptor on cord blood hematopoietic stem cells (CBHSC) and explore efficacy and feasibility of intervention in vitro. The expression and activity of active groups in P, E-selectin ligands on CD34+ cells from cord blood, bone marrow and peripheral blood were detected by flow cytometry; meanwhile the expression of active groups in selectin ligands on CD34+ cells treated by fucosyl transferase in vitro was determined by flow cytometry. The results indicated that the expression levels of CD26 on the surface of stem/progenitor cells (CD34+) from cord blood, bone marrow and peripheral blood were (7.62+/-0.63)%, (6.35+/-0.89)% and (6.18+/-0.91)% (p>0.05) respectively. And the activities of CD26 of the three sources of stem cells were 67.15 U/1000 cells (1 U=1 pmol/min), 26.85 U/1000 cells and 20.95 U/1000 cells respectively, in which the activity of CD26 on surface of CD34+ from cord blood was significantly higher than that from other both sources (p<0.01). The expression levels of P-selectin ligand on the stem/progenitor cells three kinds were (83.46+/-6.33)%, (15.65+/-0.89)% and (80.17+/-6.85)%, and the expression levels of E-selectin ligand on stem/progenitor cells of three kinds were (25.31+/-1.03)%, (26.34+/-0.89)% and (29.79+/-1.78)% respectively. The expression of E-selectin ligand on the surface of cord blood stem/progenitor cell CD34+ increased from (25.31+/-1.03)% to (63.23+/-1.08)% after glycosylation engineering. It is concluded that there is no significant difference of the expression of CD26 between the three sources of stem/progenitor cells, but the activity of CD26 in cord blood was obviously higher than that in bone marrow and peripheral blood. The expression of P-selectin ligand on bone marrow stem/progenitor cell was lower than that on stem cells of cord blood and peripheral blood. Glycosylation engineering can promote and elevate the expression of E-selectin ligand on the surface of CD34+ cells from cord blood.
Antigens, CD34 ; metabolism ; Bone Marrow Cells ; cytology ; metabolism ; Cells, Cultured ; Dipeptidyl Peptidase 4 ; metabolism ; Fetal Blood ; cytology ; Hematopoietic Stem Cells ; cytology ; metabolism ; Humans ; Receptors, Fibroblast Growth Factor ; metabolism ; Sialoglycoproteins ; metabolism ; Stem Cells ; cytology ; metabolism

OBJECTIVETo observe the effect of Astragalus-Angelica Mixture (AAM) on osteopontin (OPN) expression in rats with chronic nephrosclerosis.

METHODSChronic nephrosclerosis model rats induced by repeated intraperitoneal injection of puromycin were randomly divided into the model group, AAM group and Irbesartan (an antagonist of angiotensin) group. The experimental course lasted 12 weeks. Blood and urine samples were examined by biochemical method. Kidney tissue was taken for pathological stain and immunohistochemical method and was applied to examine OPN expression, mononuclear macrophage, laminin in extracellular matrix and decorin expressions.

RESULTSAAM showed the effects of decreasing urinary protein and improving renal function similar to that of Irbesartan. It also could alleviate the pathological damage of kidney tissue, especially in decreasing renal tubular mesenchymal damage index. The accumulation of decorin and laminin in the mesenchymal extracellular matrix significantly decreased. Renal tubular OPN expression and mesenchymal infiltration of mononuclear macrophage decreased significantly and in a positive correlated manner (r = 0.885, P < 0.01).

CONCLUSIONAAM has similar renal protective action to that of Irbesartan, this action may be related to the inhibition of up-regulated OPN expression.

Animals ; Astragalus Plant ; Drug Synergism ; Drugs, Chinese Herbal ; pharmacology ; Male ; Nephrosclerosis ; chemically induced ; metabolism ; Osteopontin ; Phytotherapy ; Puromycin ; Rats ; Rats, Sprague-Dawley ; Sialoglycoproteins ; biosynthesis