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Biomedical subjects

T Murata

Publications and source records attributed to T Murata.

At least 307 records · Page 17Linked to original sources
PubMed1997

Human ovarian-carcinoma cell lines express IL-4 and IL-13 receptors: comparison between IL-4- and IL-13-induced signal transduction.

We have reported that human ovarian-carcinoma cell lines express high-affinity IL-4 receptor. Since IL-4R has been hypothesized to share a chain with IL-13R, we investigated whether ovarian cancer cells express IL-13 receptor. In the present study, we report that the ovarian-carcinoma cell lines IGROV-1 and PA-1 express varying numbers of high-affinity IL-13 receptors. Furthermore, IL-13 inhibited the binding of IL-4 on both ovarian-carcinoma cell lines, while IL-4 did not inhibit IL-13 binding on IGROV-1 cell line. IL-13 and IL-4 induced the phosphorylation of JAK1, JAK2 and Tyk2 Janus kinases in PA-1 cells. In contrast, JAK3 tyrosine kinase was expressed in PA-1 cells, but IL-4 or IL-13 did not augment its phosphorylation. In IGROV-1 cells, Tyk2 was constitutively phosphorylated and this phosphorylation was augmented by IL-4 or IL-13. JAK1 and JAK2 but not JAK3 were expressed but only JAK2 was faintly phosphorylated in response to either IL-13 or IL-4 respectively. IRS (insulin-receptor substrate)-1 and IRS-2 were also phosphorylated constitutively in both ovarian cancer cell lines examined, but only the phosphorylation of IRS-1 was augmented in response to IL-4 or IL-13. STAT6 was phosphorylated and activated in response to IL-4 and IL-13 in all cell lines examined. Our results demonstrate that ovarian cancer cell lines may express 2 types of IL-13R and the IL-13- or IL-4-induced signaling patterns may be slightly different in each type of receptor.

Adenocarcinoma↗
PubMed1997

The IL-13 receptor structure differs on various cell types and may share more than one component with IL-4 receptor.

We have reported on the expression and characteristics of IL-13R and have demonstrated that IL-13 competes for IL-4 binding while IL-4 did not compete for the IL-13 binding on some cell types. Based on these observations, and the size of IL-13 and IL-4 cross-linked proteins, we concluded that the receptor for IL-13 is complex and shares a subunit with the receptor for IL-4. To explore the complexity of the IL-13R, a wide variety of cell types was examined for IL-13 and IL-4 binding. We report in this work that IL-4 does not always bind well to cells that bind IL-13, but the reverse is also true. We also found that IL-4 can compete more effectively for IL-13 binding than IL-13 itself. Cross-linking studies support these observations and demonstrate that 125I-labeled IL-13 bound exclusively to a single 65- to 70-kDa protein in MA-RCC and U251 cells, while in TF-1 cells it cross-linked to two membrane proteins of 65 to 70 kDa and 140 kDa. Furthermore, by using a chimeric protein composed of IL-13 and Pseudomonas exotoxin A, we observed that IL-4 neutralized the cytotoxicity of the IL-13 toxin on COS-7 cells by blocking a common form of the two cytokine receptors. We propose that the 65- to 70-kDa form of the IL-13R is the predominant common component shared between IL-13 and IL-4R. However, the primary IL-4 binding (p140) protein also participates in the formation of the IL-13R complex in some cell types. In addition, the gamma(c) or another interactive subunit may influence IL-13 binding to its receptor complex. Thus, we propose that there are at least four forms of IL-13R.

ADP Ribose Transferases↗
PubMed1997

Comparison of IL-13- and IL-4-induced signaling in EBV-immortalized human B cells.

Interleukin 4 (IL-4) and Interleukin 13 (IL-13) have been shown to have numerous similar effects on human B cells; however, the mechanism of signal transduction is not known. We have examined IL-4- and IL-13-induced signal transduction in Epstein-Barr virus (EBV)-immortalized B cells. We demonstrate that Janus kinase 3 (JAK3) and Tyk2 but not JAK1 and JAK2 tyrosine kinases were constitutively phosphorylated in three EBV B cell lines. The phosphorylation level of Tyk2 was augmented at a low level in response to IL-13 and IL-4 in two of three cell lines; however, IL-13 did not induce or augment phosphorylation of the other JAK kinases. On the other hand, IL-4 further augmented phosphorylation of JAK3 and induced the phosphorylation of JAK1 kinases. IL-4 receptor p140 protein was also constitutively phosphorylated in two of three EBV B cell lines examined and both IL-4 and IL-13 further augmented its phosphorylation. Insulin receptor substrate (IRS)-1 or IRS-2 proteins were not constitutively phosphorylated nor did IL-13 and IL-4 induce phosphorylation of these proteins. In contrast to JAKs, IL-4-specific signal transducer and activator of transcription (STAT6) was not constitutively phosphorylated or activated in these cell lines, but both IL-4 and IL-13 induced their phosphorylation and activation. These findings suggest that in EBV-immortalized B cells JAK3 and Tyk2 proteins were constitutively phosphorylated but STAT6 protein was not constitutively phosphorylated. In addition, despite major similarities in biological effects between IL-4 and IL-13, phosphorylation patterns of JAK kinases in response to IL-13 in EBV-immortalized B cells appear to be different from those of IL-4.

Animals↗
PubMed1997

The effect of dexamethasone on the expression of activated NF-kappa B in adjuvant arthritis.

The transcription factor NF-kappa B plays a significant role in inflammatory diseases. In this study we have investigated the expression of activated NF-kappa B p65 subunit in the rat adjuvant arthritis model in a 28-day time-course experiment using immunohistochemistry. The expression of p65 was detected in the synovial lining layer and around the blood vessels in the inflamed synovium as early as Day 3 post-adjuvant injection. The cells that expressed p65 in the synovial lining were thought to be macrophage-like synoviocytes. The expression was stronger in the injected hindpaw than that in the noninjected hindpaw. Dexamethasone treatment at 1 mg/kg p.o. (Days 0-20) suppressed both the hindpaw edema and increase in p65 expression. Withdrawal of the treatment caused increases in both p65 expression and paw volume. Together these suggest that activated NF-kappa B was specifically expressed in the arthritic synovium and may play a significant role in the development of arthritis.

Animals↗
PubMed1997

Changes in bone mineral density in rat adjuvant arthritis.

This study demonstrates that systemic and local decreases in bone mineral density (BMD) occurred with Freund's complete adjuvant injection in the rat right footpad using dual energy X-ray absorptiometry. The rats were assigned to either adjuvant-treated or non-treated control groups composed of eight animals each. There was significant decrease in BMD in the adjuvant group compared to the control group at the distal region of femur or proximal region of tibia on Day 7 post-adjuvant injection (P < 0.05). On the other hand, the femur or tibia of the noninjected side showed a smaller and delayed decrease in BMD than did the injected side. These decreases in BMD were seen in not only the trabecular but also the cortical bone. In addition, the vertebrae also showed delayed but significant decrease (P < 0.05) in BMD on Day 21.

Animals↗
PubMed1997

Concentration of catecholamines and indoleamines in the cerebrospinal fluid of patients with vascular parkinsonism compared to Parkinson's disease patients.

The concentration of catecholamines and indoleamines in the cerebrospinal fluid of patients with vascular parkinsonism (VP) was compared to that in patients with Parkinson's disease (PD) and controls. Compared to the controls, the concentration of tyrosine was significantly higher, and the concentration of L-dopa and 3-O-methyldopa (3-OMD) was significantly lower in both VP and PD patients. The balance between the 3-OMD/L-dopa and dopamine (DA)/L-dopa ratios was changed in favor of 3-OMD/L-dopa in both VP patients and PD patients suggesting the preservation of a compensatory mechanism. All these changes were less marked in VP patients than in PD patients. A remarkable finding was that in contrast to PD patients the concentration of DA and norepinephrine (NE) was significantly higher in VP patients than in the controls. The decrease in the concentration of 5-hydroxytryptamine (5-HT) was significantly greater in VP patients than in PD patients. In PD patients, the concentration of DA, NE, and 5-HT showed significant correlation with the severity of motor symptoms. In VP patients, the concentration of 5-HT alone showed significant correlation with the severity of motor symptoms and cognitive dysfunction. These findings suggest that VP patients may have similar disturbances in the DA synthesis pathway as PD patients, but differ from PD patients in that the concentrations of DA and NE are elevated and the decrease in the 5-HT concentration is greater in VP patients.

Aged↗
PubMed1997

The relationship between accumulation of advanced glycation end products and expression of vascular endothelial growth factor in human diabetic retinas.

Both advanced glycation end products and vascular endothelial growth factor are believed to play a role in the pathogenesis of diabetic retinopathy. It is known that vascular endothelial growth factor causes retinal neovascularization and a breakdown of the blood-retinal barrier; how advanced glycation end products affect the retina, however, remains largely unclear. The substance-Ne-(carboxymethyl)lysine is a major immunologic epitope, i.e. a dominant advanced glycation end products antigen. We generated an anti-Ne-(carboxymethyl)lysine antibody to investigate the relationship between the localization of advanced glycation end products and that of vascular endothelial growth factor in 27 human diabetic retinas by immunohistochemistry. Nine control retinas were also examined. In all 27 diabetic retinas, Ne-(carboxymethyl)lysine was located in the thickened vascular wall. In 19 of the 27 retinas, strand-shaped Ne-(carboxymethyl)lysine immunoreactivity was also observed around the vessels. In all 27 diabetic retinas, vascular endothelial growth factor revealed a distribution pattern similar to that of Ne-(carboxymethyl)lysine. Vascular endothelial growth factor was also located in the vascular wall and in the perivascular area. Neither Ne-(carboxymethyl)lysine nor vascular endothelial growth factor immunoreactivity was detected in the 9 control retinas. Vessels with positive immunoreactivity for Ne-(carboxymethyl)lysine and/or vascular endothelial growth factor were counted. A general association was noted between accumulation of Ne-(carboxymethyl)lysine and expression of vascular endothelial growth factor in the eyes with non-proliferative diabetic retinopathy (p < 0.01) and proliferative diabetic retinopathy (p < 0.05).

Aged↗
PubMed1997

Analysis of canine herpesvirus gB, gC and gD expressed by a recombinant vaccinia virus.

The genes encoding the canine herpesvirus (CHV) glycoprotein B (gB), gC and gD homologues have been reported already. However, products of these genes have not been identified yet. Previously, we have identified three CHV glycoproteins, gp 145/112, gp80 and gp47 using a panel of monoclonal antibodies (MAbs). To determine which CHV glycoprotein corresponds to gB, gC or gD, the putative genes of gB, gC, and gD of CHV were inserted into the thymidine kinase gene of vaccinia virus LC16mO strain under the control of the early-late promoter for the vaccinia virus 7.5-kilodalton polypeptide. We demonstrated here that gp145/112, gp80 and gp47 were the translation products of the CHV gB, gC and gD genes, respectively. The antigenic authenticity of recombinant gB, gC and gD were confirmed by a panel of MAbs specific for each glycoprotein produced in CHV-infected cells. Immunization of mice with these recombinants produced high titers of neutralizing antibodies against CHV. These results suggest that recombinant vaccinia viruses expressing CHV gB, gC and gD may be useful to develop a vaccine to control CHV infection.

Animals↗
PubMed1997

Increased cartilage and bone formation in spontaneously hypercholesterolemic rats.

Spontaneously hypercholesterolemic (SHC) rats are known to exhibit accelerated bone resorption. We compared endochondral bone formation induced by implantation of demineralized bone matrix (DBM) to 4-week-old SHC rats with that of age-matched Sprague-Dawley (SD) rats. When DBM prepared from adult SD rats was implanted, the cartilageous area enlarged, and C-propeptide of type II procollagen content on day 7 was higher in SHC rats. Alkaline phosphatase activity and calcium content on day 12 and tartrate-resistant acid phosphatase activity on day 19 were higher in SHC rats. These results suggest active chondrogenesis, with a subsequent increase in osteogenesis, and stimulated osteoclastic bone resorption in SHC rats. When DBM from 10-week-old SHC rats was implanted into SD or SHC rats, the levels of bone forming parameters on day 12 were reduced to one-third, suggesting inhibiting factor(s) for bone induction in bone matrix of SHC rats. In contrast, when DBM from 6-month-old SHC rats was implanted, although bone forming parameters in SD rats were comparable to the case of implantation of DBM from SD rats, the accelerated bone formation detected in SHC rats was blocked, indicating resistance to systemic bone inducing factor(s) of SHC rats in aged bone matrix. These results suggest that age-related decrease in responses to some systemic bone inducing factor may lead to the bone loss with advancing age.

Acid Phosphatase↗
PubMed1997

Suppressed bone induction by follistatin in spontaneously hypercholesterolemic rat bone.

Bone inducing activity in demineralized bone matrix (DBM) of young spontaneously hypercholesterolemic (SHC) rats has been shown to be lower than that of aged SHC rats. This study examined the involvement of bone follistatin, an activin-binding protein, in bone induction. Immunoreactive follistatin was higher in DBM from 10-week-old SHC rats (DBM-10wk) than in DBM from 6-month-old SHC rats (DBM-6mo). When DBM without follistatin supplement was implanted, the C-propeptide of type II procollagen and calcium contents on day 12 in implants of DBM-6mo were 68% and 40% higher than those of DBM-10wk, respectively. In contrast, follistatin supplement to DBM decreased C-propeptide of type II procollagen and calcium contents in implants of both DBM-10wk and DBM-6mo, and the levels of these parameters were comparable between DBM-10wk and DBM-6mo, indicating reduced formation of cartilage and bone. These findings suggest that 1) follistatin content in bone matrix decreases with advancing age in SHC rats, and 2) the follistatin interferes with endochondral bone formation. We demonstrate that the lower bone induction of DBM from young SHC rats was partly due to the abundance of follistatin in bone matrix.

Aging↗
PubMed1997

A lectin from mycelia of the fungus Ganoderma lucidum.

A lectin (GLL-M) was isolated from mycelia of Ganoderma lucidum using affinity chromatography on BSM-Toyopearl. GLL-M is a monomer in its native form with a M(r) of 18,000. Another lectin was also purified from fruiting bodies of the same fungus. The two lectins were partially compared with each other.

Amino Acids↗
PubMed1997

Ekman-Westborg-Julin syndrome. A case report.

A rare case of the Ekman-Westborg-Julin syndrome in a 15-year-old boy is presented. The patient had general macrodontia with gigantic mandibular third molars. Other dental anomalies, such as peak-shaped cuspids, central cusps, dens in dente, multituberculism, and single conical molar roots, were also present.

Adolescent↗
PubMed1997

Methodological aspects for in vitro characterization of receptor binding using 11C-labeled receptor ligands: a detailed study with the benzodiazepine receptor antagonist [11C]Ro 15-1788.

As a complement to in vivo studies with positron emission tomography (PET), it is desirable to perform in vitro characterization of newly developed 11C tracers. In this report we describe the technique for determination of receptor-ligand kinetics utilizing ligands labeled with the short-lived radionuclide 11C. The limitations and advantages are discussed. The benzodiazepine antagonist [11C]Ro 15-1788 was used as a model substance, and the use of storage phosphor plates for quantification of radioactivity was validated. Storage phosphor plates showed an excellent linear range (approximately 10[3]) and acceptable resolution (approximately 0.5 mm). Receptor-ligand kinetics, including depletion, association and dissociation, saturation and displacement were evaluated with good results through the use of short-lived radiotracers and storage phosphor plates.

Animals↗
PubMed1997

Expression of calcium-binding protein regucalcin mRNA in the cloned human hepatoma cells (HepG2): stimulation by insulin.

The expression of hepatic Ca(2+)-binding protein regucalcin in the cloned human hepatoma cells (HepG2) was investigated. The change in regucalcin mRNA levels was analyzed by Northern blotting using rat liver regucalcin complementary DNA (0.9 kb of open reading frame). Regucalcin mRNA was expressed in HepG2 cells, although the mRNA was markedly expressed in normal rat liver. Moreover, regucalcin protein in HepG2 cells was detected by Western blot analysis using a polyclonal rabbit anti-regucalcin antibody. Regucalcin mRNA expression in HepG2 cells was clearly stimulated by the culture with insulin (10(-8) M) of the effective concentration. Regucalcin protein in HepG2 cells was also increased by the treatment of insulin (10(-8) M). The present results demonstrate that regucalcin is expressed in the transformed HepG2 cells, and that the expression is stimulated by insulin.

Animals↗
PubMed1997

Molecular cloning of the cDNA coding for regucalcin and its mRNA expression in mouse liver: the expression is stimulated by calcium administration.

The molecular cloning of the cDNA coding for a Ca2+-binding protein regucalcin and its mRNA expression in mouse liver were investigated. The cDNA clone encoding a regucalcin was isolated from a mouse liver cDNA library and sequenced. Analysis of the sequence of the cloned cDNA showed that the cDNA encoded the complete amino acid sequence of the mouse regucalcin molecule; the cDNA had an open reading frame of 897 bp. Mouse regucalcin was composed of 299 amino acid residues, and its molecular weight was estimated to be 33,406 Da. The amino acid sequence of mouse regucalcin had 94% homology, as compared with that of rat regucalcin. Northern blot analysis with the mouse liver cDNA probe revealed that mouse regucalcin mRNA was mainly present in the liver but only slightly in the kidney with a size of 1.8 kb. Hepatic regucalcin mRNA level of male mouse was higher than that of female mouse. A single intraperitoneal administration of calcium chloride (5, 15, and 30 mg Ca2+/100 g body weight) to mice induced a remarkable increase in regucalcin mRNA in the liver; the increase in regucalcin mRNA levels at 30 min after calcium administration was dose-dependent. The present results demonstrate that regucalcin mRNA in mice is uniquely expressed in the liver, and that its expression is stimulated by calcium administration.

Amino Acid Sequence↗
PubMed1997

Immunolocalization of type I or type II activin receptors in the rat brain.

We have studied immunolocalization of activin receptors in the central nervous system using polyclonal antibodies (IgG) to type I (50-55 kDa, ActRI), type II (70-75 kDa, ActRII) or a subtype of type II known as type IIB (ActRIIB) receptors of activin. A total of 7 antisera to rat activin receptors was generated, i.e. 3 kinds of antisera to the extracellular domain (ActRI(81-89), ActRII(91-100), or ActRIIB(90-99)) and 4 antisera to the kinase domain (ActRI(323-333), ActRII(307-319), ActRII(407-420) or ActRIIB(306-319)). The region of aa 407-420 of ActRII is identical with that of ActRIIB. At first, we characterized these antibodies by Western blot analysis using ovarian proteins fractionated by preparative SDS-PAGE. All antibodies to ActRII and ActRIIB specifically reacted with 75 kDa-proteins which could also bind to activin-A. Anti-ActRII(91-100) antibody also reacted with 62 kDa-proteins which were capable of binding with activin-A. Although no positive reactions to anti-ActRI(81-89) antibody were seen in ovarian proteins, a positive reaction was detected at 52 kDa only when the proteins were deglycosylated. By use of these antibodies, immunolocalization of activin receptors was examined in the rat brain. The patterns of expression of activin type I and type II receptors were different. Positive reactions to anti-ActRII(91-100) antibody were detected in neurons of the cerebral cortex, hippocampus, medial amygdala and thalamus. In the hypothalamus, some neurons of the supraoptic nucleus were weakly stained, and widely scattered neurons of the lateral hypothalamic area were moderately stained. On the contrary, the most intense reactions to anti-ActRI(81-89) antibody were detected in neurons of the lateral hypothalamic area. In addition, many neurons of the cerebral cortex were also stained, but neurons of the hippocampus and the amygdala were not stained. These results suggest that activin may have physiological roles not only for hypothalamic neuroendocrinological and feeding-related systems as suggested previously but may also have functions in cortical and limbic pathways as a neuromodulator or for maintenance of neurons.

Activin Receptors↗