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Biomedical subjects

Y Yoshihara

Publications and source records attributed to Y Yoshihara.

At least 19 recordsLinked to original sources
PubMed1996

Enhancement of SPARC (osteonectin) synthesis in arthritic cartilage. Increased levels in synovial fluids from patients with rheumatoid arthritis and regulation by growth factors and cytokines in chondrocyte cultures.

OBJECTIVE: To investigate the roles of SPARC (secreted protein, acidic and rich in cysteine) (osteonectin) in arthritis, using cartilage and synovium specimens and synovial fluids (SF) from patients with rheumatoid arthritis (RA) or osteoarthritis (OA), and to examine the effects of cytokines, growth factors, and hormones on SPARC synthesis by chondrocytes in culture. METHODS: SPARC in cartilage and synovium was immunostained with monoclonal antibodies. SPARC synthesis by cultured chondrocytes was measured by Northern blot analysis, immunoblotting, and sandwich enzyme-linked immunosorbent assay. RESULTS: SPARC was identified in numerous chondrocytes in the superficial and middle zones and in regenerating chondrocytes of RA and OA joints, whereas such staining was absent in these zones of normal cartilage, except for weak signals from a few chondrocytes in the deep zone. In addition, SPARC synthesis was enhanced in synovial cells of RA and OA joints. The average SPARC level in SF was 10-fold higher in the RA than in the OA population. In rabbit articular chondrocyte cultures, administration of transforming growth factor beta 1 (TGF beta 1) and bone morphogenetic protein 2 increased SPARC levels at 24-48 hours, whereas interleukin-lbeta (IL-1 beta), IL-1 alpha, tumor necrosis factor alpha, lipopolysaccharide, phorbol myristate acetate, basic fibroblast growth factor, and dexamethasone decreased SPARC levels at 24-72 hours. TGF beta increased SPARC messenger RNA (mRNA) levels at 24 hours, whereas IL-1 beta caused a marked decrease in SPARC mRNA levels at 24 hours. Furthermore, IL-1 decreased the glycosylation of SPARC. CONCLUSION: These findings suggest that various growth factors and cytokines, including TGF beta 1 and IL-1 beta, regulate the production of SPARC by chondrocytes at pre- and posttranslational levels, and that SPARC synthesis is markedly enhanced in arthritic joints.

Adult↗
PubMed1996

Procollagen II C-propeptide in joint fluid: changes in concentration with age, time after knee injury, and osteoarthritis.

OBJECTIVE: To determine in a cross sectional study the concentrations in joint fluid of the C-propeptide of collagen II (pCol II-C) in patients with knee injury and developing osteoarthritis (OA). METHODS: Synovial fluid (SF) samples were collected from knees of healthy volunteers, from patients with injury to the knee causing lesions of the anterior cruciate ligament and/or menisci, and from patients with posttraumatic or primary OA. Concentrations of pCol II-C were determined by enzyme immunoassay with a polyclonal antiserum against the bovine propeptide. RESULTS: The median concentration of pCol II-C in joint fluid in the reference group was 1.3 ng/ml (range 0.1-5.7 ng/ml). Median concentrations of pCol II-C in joint fluid were increased 2-4-fold in all 3 study groups over that in the reference group. Very high concentrations of propeptide were noted in samples from patients younger than about 18 years. Propeptide concentrations were increased after knee injury, with a suggested peak at about 1-4 years evident for patients with cruciate ligament injury. pCol II-C levels were increased at all stages of OA development, except in the most advanced phases. CONCLUSION: The increased levels of pCol II-C in SF may reflect an increased rate of synthesis of collagen II in the joint cartilage of patients with knee injury and developing OA. The increase reaches a maximum well before radiographic changes indicative of OA are apparent, and occurs during a disease phase characterized by signs of increased degradation of collagen II, aggrecan, and other matrix components. Further studies of markers of matrix metabolism of cartilage, bone, and other joint tissues in human and animal models of OA may aid in the identification of process markers, individuals at risk, and new therapeutic targets.

Adolescent↗
PubMed1996

[Levels of chondroitin 4-sulfate, chondroitin 6-sulfate and carboxy-terminal type II procollagen peptide in knee synovial fluid after injury to the anterior cruciate ligament].

Changes in the metabolism of articular cartilage associated with injury to the anterior cruciate ligament (ACL) is known to be one of the important factors for the progression to secondary osteoarthritis. To investigate the efficacy of biochemical markers for monitoring the cartilage metabolism after injury to ACL, we measured the levels of chondroitin 4-sulfate (C-4S), chondroitin 6-sulfate (C-6S) and carboxy-terminal type II procollagen peptide (pCOL II-C) in knee synovial fluid (SF) from the patients with ACL rupture and compared with those in knee osteoarthritis (OA). Within 10 days after ACL rupture, levels of C-6S and C-4S in SF were significantly higher than those in early stage of OA. Both levels decreased gradually and became to the same levels as those in early stage of OA at 30 days after the injury. In contrast, pCOL II-C levels in SF just after the injury were observed to be lower than those in early stage of OA. Then they increased gradually to the levels of those in early stage of OA at 30 days after the injury. High levels of C-6S and C-4S in SF just after ACL rupture seemed to reflect the increased release of matrix fragments caused by cartilage destruction associated with the injury. pCOL II-C levels in SF seemed to reflect the repairing process that increased slowly after the cartilage destruction. Measurement of these cartilage derived macromolecules in SF could be useful tools for monitoring the metabolism in articular cartilage after injury.

Adult↗
PubMed1995

Increased levels of stromelysin-1 and tissue inhibitor of metalloproteinases-1 in sera from patients with rheumatoid arthritis.

OBJECTIVE: To evaluate the efficacy of stromelysin-1 (matrix metalloproteinase-3 [MMP-3]) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in serum as markers for joint inflammation in rheumatoid arthritis (RA). METHODS: Levels of both macromolecules in sera from 97 healthy controls, 109 patients with RA, and 47 patients with osteoarthritis (OA) were measured by respective 1-step sandwich enzyme immunoassays. In the patients with RA, serum levels of MMP-3 and TIMP-1 were investigated in relation to laboratory and clinical measures of disease activity. In addition, the relationships between serum and synovial fluid (SF) levels in paired samples from individual patients were examined. RESULTS: Serum levels of both MMP-3 and TIMP-1 in RA patients were significantly higher than those in OA patients and in healthy controls (P < 0.001), and were shown to correlate with traditional systemic markers of inflammation including the erythrocyte sedimentation rate and C-reactive protein level, and with the Lansbury articular index. In addition, it was noted that serum levels of MMP-3 correlated with the corresponding values in paired SF samples obtained concurrently from patients with RA (rs = 0.588, P < 0.001), while such correlations were not found for TIMP-1 levels. CONCLUSION: Our results support the notion that levels of both MMP-3 and TIMP-1 in RA patient sera are increased in association with inflammation. Furthermore, the level of MMP-3 in serum provides a particularly useful marker of inflammatory activity in the joints of patients with RA.

Adult↗
PubMed1995

Overlapping and differential expression of BIG-2, BIG-1, TAG-1, and F3: four members of an axon-associated cell adhesion molecule subgroup of the immunoglobulin superfamily.

Axon-associated cell adhesion molecules (AxCAMs) play crucial roles in the formation, maintenance, and plasticity of functional neuronal networks. We report here a molecular cloning of a novel AxCAM, BIG-2. BIG-2 is a member of TAG-1/F3 subgroup of the immunoglobulin (Ig) superfamily, with six Ig-like domains, four fibronectin type III-like repeats, and a glycosyl phosphatidylinositol-anchoring domain. Recombinant BIG-2 protein had a neurite outgrowth-promoting activity when used as a substrate for neurons in vitro. To survey the spatial expression pattern of BIG-2 in comparison with other TAG-1/F3 subgroup members, an in situ hybridization analysis was performed in adult and developing rat brain sections with riboprobes specific for BIG-2, BIG-1, TAG-1, and F3. The four AxCAM transcripts displayed cell type-specific expression patterns with overlapping and distinct profiles. In adult hippocampus, for example, we observed BIG-1 mRNA specifically in granule cells of the dentate gyrus, BIG-2 mRNA highly in the CA1 pyramidal cells, TAG-1 mRNA predominantly in the CA3 pyramidal cells, and F3 mRNA in neurons in all of these fields. These results suggest that BIG-2, BIG-1, TAG-1, and F3 may play important roles in the formation and maintenance of specific neuronal networks in the brain.

Amino Acid Sequence↗
PubMed1995

Use of an SDS-gel-separated protein band as a ligand for affinity chromatography: procedure and application to the purification of domain-specific antibodies against alpha-actinin.

This paper describes a simple and efficient method for preparing affinity columns. We used protein separated by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis as a ligand. Protein bands detected in a polyacrylamide gel were electrophoretically transferred to CNBr-activated Sepharose using a buffer containing Nonidet P-40. The amount of ligand protein coupled to activated Sepharose by our method was almost comparable to that obtained by conventional coupling procedure with a native ligand protein. Using affinity columns prepared by this method, we have successfully purified anti-alpha-actinin antibody and antibodies highly specific to the rod domain of alpha-actinin from the antiserum. This new method should be useful for separating a specific antibody from an antiserum that has been raised against multiple antigens. In addition, the use of the SDS-gel-fractionated band facilitates the coupling of proteins that have low solubility under the coupling conditions.

Actinin↗
PubMed1995

Significance of the levels of carboxy terminal type II procollagen peptide, chondroitin sulfate isomers, tissue inhibitor of metalloproteinases, and metalloproteinases in osteoarthritis joint fluid.

The joint fluid levels of several molecules that reflect the anabolism and catabolism of cartilage matrix and its inflammation were quantitated in patients with primary osteoarthritis (OA) and traumatic arthritis. The carboxy terminal type II procollagen increased in primary OA and traumatic arthritis joint fluid and was thought to be a good marker of the repair response of chondrocytes. We found that the increase of this molecule in the joint correlated well with body mass index in primary OA and the degree of cartilage erosion caused by joint instability in traumatic arthritis. Chondroitin 6-sulfate, an integral part of human aggrecan, was also high in OA and traumatic arthritis joint fluids, and showed a similar distribution with keratan sulfate in each disease group. Stromelysin-1 and tissue inhibitor of metalloproteinases-1 levels in joint fluid were very high in RA, but levels in patients with OA were low. Carboxy terminal type II procollagen appeared most sensitive in the evaluation of risk factors of OA such as obesity and joint instability, compared to other markers tested.

Chondroitin Sulfates↗
PubMed1994

Immunohistochemical demonstration of embryonic expression of an odor receptor protein and its zonal distribution in the rat olfactory epithelium.

Using an antibody raised against an odor receptor protein, we investigated immunohistochemically the spatial distribution in the embryonic and adult rat olfactory epithelium of the olfactory receptor neurons that express the odor receptor protein. In adults, the immunoreactive olfactory receptor neurons were intermingled with immuno-negative receptor neurons, but were mostly restricted within a circumferential zone located in the lateral part of the epithelium. The immunoreactive olfactory receptor neurons were observed as early as embryonic day 14, with a strong tendency to localize in the lateral part of the epithelium. These results indicate that both selection of the odor receptor protein by individual olfactory receptor neurons and zonal segregation of the odor receptor protein expression occur early in embryonic development of the olfactory system.

Animals↗
PubMed1994

Telencephalin: a neuronal area code molecule?

Cell adhesion molecules (CAMs) with expression restricted to specific developmental and structural units of the brain and/or selective neuronal types would play critical roles in the formation of functional neuronal networks. In this article, we summarize recent progress in knowledge on a brain segment-specific CAM, telencephalin (TLN). TLN has the following characteristic properties. (1) TLN is a neuronal glycoprotein whose expression is restricted within telencephalon, the most rostal segment of the brain. (2) TLN is localized to the soma-dendritic membrane of subsets of telencephalic neurons, but not to the axonal membrane. (3) Abrupt appearance of TLN around birth parallels the timing of dendritic development and synapse formation in the telencephalon. (4) TLN belongs to the immunoglobulin superfamily and its structure is most closely related to intercellular adhesion molecules (ICAMs)-1 and -3. These findings suggest that TLN is the first example of dendrite-associated cell adhesion molecules (DenCAMs) and that TLN may be involved in the brain segmental organization, cell-cell interactions during dendritic development, and maintenance of functional neuronal networks. We discuss the possibility that TLN is an area code-like address signal that is displayed selectively by telencephalic neurons and is decoded by specific subsets of growing axons to make proper synaptic connections.

Animals↗
PubMed1994

An ICAM-related neuronal glycoprotein, telencephalin, with brain segment-specific expression.

Telencephalin (TLN) is a 130 kd glycoprotein expressed exclusively in neurons of the telencephalon, the most rostral brain segment. In the neurons, TLN is localized to soma-dendritic membrane but not to axonal membrane. In this study, we have cloned cDNA encoding rabbit and mouse TLN. The cDNA-derived primary structure of TLN predicts an integral membrane protein with nine tandem immunoglobulin-like domains in an extra-cellular region, a transmembrane domain, and a short cytoplasmic tail. The distal eight immunoglobulin-like domains of TLN show highest homology with the immunoglobulin-like domains of intracellular adhesion molecules (ICAMs) 1, 2, and 3/R. The structural similarity of TLN with ICAMs provides a new and strong link between immunoglobulin superfamily molecules in the nervous and immune systems. TLN is an example of a dendrite-associated cell adhesion molecule involved in the brain's segmental organization, cell-cell interactions during dendritic development, and maintenance of functional neuronal networks.

Amino Acid Sequence↗
PubMed1994

BIG-1: a new TAG-1/F3-related member of the immunoglobulin superfamily with neurite outgrowth-promoting activity.

We have cloned a rat cDNA for a novel brain-derived immunoglobulin (Ig) superfamily molecule, BIG-1, by using PCR based on the amino acid sequences of the two closely related and well-known Ig superfamily members, rat TAG-1 and mouse F3. BIG-1 is a glycosylphosphatidylinositol-anchored membrane protein with six Ig-like domains and four fibronectin type III repeats, belonging to the TAG-1/F3 subgroup. The expression of BIG-1 mRNA is developmentally regulated with the highest level in the adult brain. It is restricted to subsets of neurons such as Purkinje cells of the cerebellum, granule cells of the dentate gyrus, and neurons in the superficial layers of the cerebral cortex. Recombinant BIG-1 protein has a neurite outgrowth-promoting activity when used as a substrate for neurons in vitro. These results suggest that BIG-1 may be involved in the formation and maintenance of neuron type-specific networks in the brain.

Amino Acid Sequence↗
PubMed1993

Expression of prostaglandin endoperoxide synthase in rat brain.

Developmental and regional expression of prostaglandin endoperoxide synthase (PES) transcript was examined in the rat brain and in primary mixed cultures of neurons and glial cells from neonatal brain. Although the PES mRNA level in the brain was much lower than that in peripheral rat tissues such as lung, liver, spleen and kidney, a significant 3.0 kb band was detected in brain samples by Northern blot analysis. During development, PES mRNA was first detectable at postnatal day 7, and increased thereafter toward adulthood. The highest level of 3.0 kb PES mRNA was observed in the olfactory bulb, midbrain, and hypothalamus; and the lowest level in the hippocampus. In primary cultures of neonatal brain cells, the level of 3:0 kb transcript of PES transiently and dramatically increased about 30-fold on the third day after plating. Simultaneously, two cross-hybridizing signals were detected at 4.0 and 7.0 kb. This increase in PES mRNAs was completely inhibited by addition of cytosine-1-beta-D-arabinofuranoside. The induction of PES mRNA was in parallel with the increase in PES protein, as assessed by Western blot analysis. Immunostaining of cultured cells with anti-PES monoclonal antibody revealed that PES protein was induced mainly in neurons but not in glial cells. These results suggest that PES is expressed in the central nervous system at a low concentration under normal conditions, and that the neuronal cells possess an ability to express high levels of PES mRNA and protein.

Aging↗
PubMed1993

Odor stimulation causes disappearance of R4B12 epitope on axonal surface molecule of olfactory sensory neurons.

Monoclonal antibodies R4B12 and R1D1 label the same subsets of rabbit primary olfactory axons. In the present study, we characterized the R4B12 antigens using immunohistochemical, immunoelectron-microscopic, and biochemical techniques. The R4B12 antigens are expressed on the surface membrane of a subset of primary olfactory axons. Western blot analysis revealed the existence of two forms (115,000 and 90,000 mol.wt) of the R4B12 antigens with different membrane-anchoring structures. Of the two forms, the smaller antigen (90,000 mol. wt) is anchored to the plasma membrane via a phosphatidylinositol linkage and expressed exclusively by the olfactory system. When the rabbit olfactory epithelium was stimulated by odors for 2-8 h in situ, the R4B12 immunoreactivity disappeared from the primary olfactory axons in the glomeruli of the olfactory bulb. These results suggest that the cell surface antigens R4B12 expressed by subsets of primary olfactory axons undergo stimulus-dependent changes by odor stimulation and may be involved in plasticity of olfactory sensory neurons.

Animals↗
PubMed1993

Joint fluid carboxy-terminal type II procollagen peptide as a marker of cartilage collagen biosynthesis.

Joint fluid levels of carboxy-terminal type II procollagen peptide (pCOL II-C) were measured in osteoarthritis, rheumatoid arthritis and traumatic arthritis by a newly developed one-step enzyme immunoassay (EIA). The detection limit of the new method was as low as 0.2 ng/ml. The levels of pCOL II-C were significantly (P < 0.001) higher in osteoarthritis and traumatic arthritis than in rheumatoid arthritis. In osteoarthritis, pCOL II-C levels were higher in moderately afflicted patients. Since type II collagen is a unique component of cartilage, pCOL II-C levels in joint fluids could reflect the synthetic activity of type II collagen of chondrocytes in the diseased joint and therefore could be utilized as a simple marker of type II collagen synthesis in articular cartilage in joint diseases.

Adult↗
PubMed1993

R2D5 antigen: a calcium-binding phosphoprotein predominantly expressed in olfactory receptor neurons.

R2D5 is a mouse monoclonal antibody that labels rabbit olfactory receptor neurons. Immunoblot analysis showed that mAb R2D5 recognizes a 22-kD protein with apparent pI of 4.8, which is abundantly contained in the olfactory epithelium and the olfactory bulb. We isolated cDNA for R2D5 antigen and confirmed by Northern analysis and neuronal depletion technique that R2D5 antigen is expressed predominantly, but not exclusively, in olfactory receptor neurons. Analysis of the deduced primary structure revealed that R2D5 antigen consists of 189 amino acids with calculated M(r) of 20,864 and pI of 4.74, has three calcium-binding EF hands, and has possible phosphorylation sites for Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) and cAMP-dependent protein kinase (A kinase). Using the bacterially expressed protein, we directly examined the biochemical properties of R2D5 antigen. R2D5 antigen binds Ca2+ and undergoes a conformational change in a manner similar to calmodulin. R2D5 antigen is phosphorylated in vitro by CaM kinase II and A kinase at different sites, and 1.81 and 0.80 mol of Pi were maximally incorporated per mol of R2D5 antigen by CaM kinase II and A kinase, respectively. Detailed immunohistochemical study showed that R2D5 antigen is also expressed in a variety of ependymal cells in the rabbit central nervous system. Aside from ubiquitous calmodulin, R2D5 antigen is the first identified calcium-binding protein in olfactory receptor neurons that may modulate olfactory signal transduction. Furthermore our results indicate that olfactory receptor neurons and ependymal cells have certain signal transduction components in common, suggesting a novel physiological process in ependymal cells.

Animals↗