Biomedical subjects

M Monden

Publications and source records attributed to M Monden.

At least 253 records · Page 14Linked to original sources

PubMed1996

Fluid shear stress induces actin polymerization in human neutrophils.

We have previously reported that a physiological range of shear stress induces neutrophil homotypic aggregation mediated by lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-3 (ICAM-3) interactions. To further characterized the homotypic aggregation, actin polymerization was investigated in neutrophils stimulated by shear stress in comparison with formyl-methionyl-leucyl-phenylalanine (fMLP). In fMLP-stimulated neutrophils, actin polymerization was localized in the pseudopods, and this reaction was not mediated by a cytosolic level of Ca2+. In contrast to fMLP stimulation, the actin polymerization induced by shear stress in a cone-plate viscometer was localized in cell-cell contact regions, and this polymerization required the increase of intracellular Ca2+. This shear stress-induced actin polymerization was not observed when neutrophils were pretreated with anti-LFA-1 or anti-ICAM-3 antibody. In conclusion, LFA-1 and ICAM-3 interaction mediated by the increase of [Ca2+]i generated the intercellular signal in order to accumulate F-actin in the cell-cell contact regions.

Actins↗

PubMed1996

Anti-interleukin-6 receptor antibody prevents muscle atrophy in colon-26 adenocarcinoma-bearing mice with modulation of lysosomal and ATP-ubiquitin-dependent proteolytic pathways.

Progression of skeletal muscle atrophy is one of the characteristic features in cancer patients. Interleukin-6 (IL-6) has been reported to be responsible for the loss of lean body mass during cancer cachexia in colon-26 adenocarcinoma (C-26)-bearing mice. This study was carried out to elucidate the intracellular proteolytic pathways operating in skeletal muscle in C-26-bearing mice, and to examine the effect of anti IL-6 receptor antibody on muscle atrophy. On day 17 after tumor inoculation, the gastrocnemius muscle weight of C-26-bearing mice had significantly decreased to 69% of that of the pair-fed control mice. This weight loss occurred in association with increases in the mRNA levels of cathepsins B and L, poly-ubiquitin (Ub) and the subunits of proteasomes in the muscles. Furthermore, enzymatic activity of cathepsin B+L in the muscles also increased to 119% of the control. The administration of anti-murine IL-6 receptor antibody to C-26-bearing mice reduced the weight loss of the gastrocnemius muscles to 84% of that of the control mice, whose enzymatic activity of cathepsin B+L and mRNA levels of cathepsin L and poly-Ub were significantly suppressed compared with those of the C-26-bearing mice. Our data indicate that both the lysosomal cathepsin pathway and the ATP-dependent proteolytic pathway might be involved in the muscle atrophy of C-26-bearing mice. The results also suggest that anti IL-6 receptor antibody could be a potential therapeutic agent against muscle atrophy in cancer cachexia by inhibiting these proteolytic systems.

Adenocarcinoma↗

PubMed1996

Temperature-dependent enhancement of proteolysis in C2C12 myotubes in association with the activation of 26S proteasome.

The effect of temperature on protein metabolism of C2C12 myotubes was investigated in order to estimate the potential effect of fever on muscle catabolism. The half-life of long-lived proteins in C2C12 myotubes was significantly (13%) shorter when incubated at 40 degrees C than at 37 degrees. The activities of cathepsins B and L were not significantly different at 37 and 40 degrees C, nor were the levels of the protein and mRNA of the two cathepsins. In contrast, the chymotrypsin-like activity of 26S proteasome was elevated by 53% at 40 degrees C, compared to that at 37 degrees C, although it was not associated with an increase in the levels of the protein and mRNA of proteasome subunits. mRNA levels of calpain and ubiquitin were not affected by temperature. It is concluded that temperature-dependent enhancement of proteolysis in C2C12 myotubes is associated with an increase in 26S proteasome activity.

Animals↗

PubMed1996

Mutations of the transforming growth factor beta type II receptor gene and microsatellite instability in gastric cancer.

Forty-three sporadic gastric cancers were analyzed with regard to whether mutations of simple repeated sequences in the transforming growth factor beta type II receptor (TbetaR-II) gene are associated with microsatellite instability (MSI) and gastric carcinogenesis. In 12 of the 43 cancers (28%), MSI was observed at least at 1 of the 2 microsatellite loci. Frameshift mutations of the TbetaR-II gene, all of which were 1 base deletion of 10 adenine repeats, were detected in 3 of 6 cancers, with MSI at 2 loci. However, mutations were not detected in 6 cancers, with MSI only at 1 locus and 31 cancers without MSI. Moreover, microanalysis in these cases revealed that the mutant-type alleles of TbetaR-II were invariably common in different areas within the tumor, in contrast to the markedly variable alleles of microsatellite loci. Our results suggest that frameshift mutation of the TbetaR-II gene may be a critical event associated with MSI and may contribute to carcinogenesis of the stomach. One of the possible mechanisms of escape from growth control by TGFbeta during gastric carcinogenesis could involve frameshift mutations of the TbetaR-II gene caused by DNA replication errors.

Adenine↗

PubMed1996

Expression of truncated midkine in human colorectal cancers.

Midkine (MK) is a growth differentiation factor originally found as the product of a retinoic acid-responsive gene. The expression of MK was examined in 35 surgically resected specimens of primary colorectal cancer using the reverse transcription-polymerase chain reaction (RT-PCR). All of the cancerous tissues expressed MK. In 5/25 cancerous tissues a truncated form of MK, which was recently found in various human tumor cell lines, was detected in addition to the full-size MK. In contrast, the truncated from of MK could not be detected in non-cancerous tissues, whereas the wild-type form was detected in 8/10 non-cancerous tissues. These results suggest that the expression of the truncated form of MK may be associated with tumorigenesis.

Carrier Proteins↗

PubMed1996

Immunohistochemical study of Cell Cycle Modulators in G(1)-S Transition in Clinical Breast Cancer Tissue.

In the present study, we investigated immunolocalization of the modulators of G(1)-S transition by using monoclonal or polyclonal antibodies for each of the modulators in 65 cases of clinical breast cancer. Two prominent cyclin dependent kinase(cdk)-cyclin complexes, cdk4-cyclin D and cdk2-cyclin E, were proved to have different modes of mutual expression. cdk4-positive lesions were found to equal cyclin D-expressing lesions in 55 cases, while the former were more extensive than the latter in 9 cases. On the other hand, cyclin E expression was detected in all the cases examined and was more dominant than that of cdk2/cdc2 in as many as 40 cases whereas the reverse was seen in only 1 case. Interestingly, cdk4(P<0.01)and cyclin E(P<0.05)expressions showed an inverse relationship with the tumor size and the cancer stage. A similar tendency was also detected for two other positive modulators of G(1)-S transition, indicating that cell cycle progression must be regulated by the cancer itself once it has grown to a certain extent. p21, which has been regarded as a universal inhibitor of the cell cycle, was expressed in 43.1% of the cases examined and its immunoreactivity showed an inverse relationship with lymph node metastasis(P<0.05). It also tended to be absent more frequently in T3 or larger cancers and stage III cases. Moreover, two patients who died as a result of cancer and three patients with recurrence were all p21 negative, suggesting that p21 is prognosticably the most significant of all these modulators.

Journal Article↗

PubMed1996

The tumor suppressor protein APC colocalizes with beta-catenin in the colon epithelial cells.

The APC gene is mutated in familial adenomatous polyposis and sporadic colorectal tumors. The product of this gene is a 300 kDa cytoplasmic protein associated with catenin. In the present study, we examined the subcellular localization of the APC protein and beta-catenin in the mouse colon by double-labeling immunocytochemistry. While the APC protein was localized in the lateral and apical cytoplasm and in microvilli of the epithelial cells, beta-catenin was present exclusively in the lateral cytoplasm. Double-labeling-immunoelectron microscopy demonstrated precise colocalization of the APC protein and beta-catenin along the lateral plasma membrane. These results suggest that the APC protein functions in cooperation with beta-catenin in the lateral cytoplasm but has other functions independent of beta-catenin in the apical cytoplasm and in microvilli.

Adenomatous Polyposis Coli Protein↗

PubMed1996

Molecular cloning and characterization of a newly identified member of the cadherin family, PB-cadherin.

We have isolated cDNA clones encoding novel proteins belonging to the cadherin family. These novel proteins are encoded by two distinct mRNA species generated by alternative splicing from a single gene, and based on preferential expression in the pituitary gland and brain, we named it PB-cadherin. One mRNA species encodes long type PB-cadherin composed of 803 amino acid residues with a longer cytoplasmic domain, whereas the other species encodes short-type PB-cadherin composed of 694 amino acid residues with a shorter cytoplasmic domain. Both long and short type PB-cadherin contain five repeats of a cadherin motif in the extracellular domain, the transmembrane domain, and the cytoplasmic domain, and the deduced amino acid sequences have a 30% homology to those of E-, N-, and P-cadherins. Although the primary structure of N-terminal amino acids is identical between long and short type PB-cadherin, the following structures in the cytoplasmic regions are completely different. The long type PB-cadherin but not the short type contains the putative catenin-binding domain. When these two distinct forms of PB-cadherins were stably expressed in L cells, L cells expressing long type PB-cadherin or short type PB-cadherin both acquired a Ca2+-dependent cell adhesion property, thereby indicating that both types of PB-cadherin are responsible for Ca2+-dependent cell adhesion. Persistent expression of PB-cadherin mRNA was found in the brain of rat embryos at least from embryonic day 15 to the postnatal period. In situ localization of PB-cadherin mRNA in the adult rat brain indicated that PB-cadherin mRNA is expressed in the inner granular layer of the olfactory bulb, Purkinje cell layer of the cerebellum, and in the pineal gland. PB-cadherin may play an important role in morphogenesis and tissue formation in neural and non-neural cells for the development and maintenance of the brain and neuroendocrine organs by regulating cell-cell adhesion.

Aging↗

PubMed1996

E-cadherin mediated adhesion system in cancer cells.

BACKGROUND: Cadherins are the family of functionally related transmembrane glycoproteins responsible for the Ca(2+)-dependent cell-cell adhesion mechanism that is crucial for the mutual association of vertebrate cells. Because cell dissociation and acquisition of cell motility occur in cancer invasion and metastasis, it is important to study the possible involvement of mutual cell adhesion of cancer cells. METHODS: The results and observations reported in the literature on the involvement of cadherin-mediated adhesion in the behavior of cancer cells are reviewed and compared with the authors' experimental and clinical studies. RESULTS: In the initial studies, E-cadherin and alpha-catenin or beta-catenin expression have been investigated immunohistochemically. Although these molecules showed strong expression in noncancerous epithelial tissues without exception, the reduction of the immunoreactivities of cancer cells has been observed. These observations suggest that the impaired E-cadherin mediated adhesion system is a characteristic of cells with malignant transformation. The impaired expression of E-cadherin is frequently observed in tumors with aggressive histopathologic characteristics that are defined by morphologic degree of invasiveness and metastasis. Three mechanisms of the inactivation of cadherin action could be proposed in human cancers by in vivo and in vitro studies. The first is downregulation of E-cadherin expression and its gene mutation. The second is abnormality of deletion of catenins, including the absence of alpha-catenin. The third abnormality of this adhesion system is biochemical modification of catenins such as the phosphorylation of beta-catenin. CONCLUSIONS: Numerous studies have suggested that the E-cadherin adhesion system is disturbed in cancer cells through various mechanisms and these impaired functions of E-cadherin contribute to the release of cancer cells from the primary lesion and to cell dedifferentiation.

Animals↗

PubMed1996

Hemostasis activation during sclerotherapy of lower extremity varices.

The influence of compression sclerotherapy upon hemostasis activation was investigated in 41 consecutive patients with lower extremity varices by serial measurement of thrombin-antithrombin III complexes (TAT), D-dimer, fibrinogen and C-reactive protein (CRP). Blood sampling was carried out before operation and on the 7th and 28th post-operative day in patients randomly assigned to either the control group (n = 18), in which high ligation of sapheno-femoral junction and local excision of varices were performed, or the sclerotherapy group (n = 23) in which the comparable surgical intervention and compression sclerotherapy using hypertonic saline were performed simultaneously. In both groups, the TAT, D-dimer and fibrinogen concentrations at day 7 were significantly elevated compared to the value before operation while CRP showed no significant change during the observation period. In the sclerotherapy group, higher incidence of superficial thrombosis was observed and the TAT concentration at day 7 was significantly higher than that in the control group (p < 0.01), and the TAT at day 28 was still significantly elevated compared to the pre-operative level (p < 0.05). However, no relationship between TAT and D-dimer concentrations and the extent of superficial thrombosis was observed. We conclude that compression sclerotherapy for lower extremity varices causes latent activation of coagulation system and can be a risk factor for venous thromboembolism.

Antithrombin III↗

PubMed1996

Epithelial-mesenchymal transformation of a newly established cell line from ovarian adenosarcoma by transforming growth factor-beta1.

We report on 2 cell lines (designated OVAK-I and OVAK-II) established from an adenosarcoma, a rare variant of a malignant Mullerian mixed tumor, of the ovary. OVAK-I was not tumorigenic in nude mice and showed no responsiveness to transforming growth factor (TGF)-beta1, whereas OVAK-II was tumorigenic and had various biological properties. Light- and electron-microscopic studies showed that the morphology of the cells was converted from an epithelial to a mesenchymal form by TGF-betaI. Furthermore, the protein and mRNA expressions of the epithelial marker carcinoembryonic antigen and the mesenchymal marker vimentin were down- and up-regulated, respectively, by TGF-beta1. These findings suggested that TGF-beta1 plays a role in epithelial-mesenchymal transformation and support the single-stem-cell theory which explains the origin of malignant Mullerian mixed tumors: that the epithelial and mesenchymal components of these tumors are of common stem-cell origin.

Adenosarcoma↗

PubMed1996

LFA-1/ICAM-3 mediates neutrophil homotypic aggregation under fluid shear stress.

We found that human neutrophils undergo homotypic aggregation by loading the physiological range of fluid shear stress (12-30 dynes/cm2). Under the fluid shear stress, an increase of intracellular Ca2+ concentration of neutrophils was observed. This increase of intracellular Ca2+ concentration was caused by Ca2+ influx, and the blockage of the flux by NiCl2 suppressed the neutrophil homotypic aggregation. Furthermore, this neutrophil aggregation under fluid shear stress was completely inhibited by pretreatment with antibody against LFA-1 or ICAM-3. These results suggested that NiCl2-sensitive Ca2+ channel played an important role in LFA-1/ICAM-3-mediated neutrophil homotypic aggregation under fluid shear stress.

Antigens, CD↗

PubMed1996

Platelet microparticles: a carrier of platelet-activating factor?

Platelet-activating factor (PAF) has been considered to be released in a soluble form from activated platelets. Also a considerable number of microparticles were released from stimulated platelets. To evaluate the possibility that microparticles contain PAF, the amount of PAF in whole activated platelets, microparticles and the suspending medium was determined by means of bioassay. The total amount of PAF released from 3 x 10(8) platelets activated with thrombin (0.5 U/ml) plus collagen (10 micrograms/ml) for 10 minutes was 4.6 +/- 1.5 x 10(-12) mol (n = 8, mean +/- S.D.). Eighty-seven percent of the PAF released from platelets was associated with microparticles. PAF released in microparticles is susceptible to plasma acetylhydrolase and may be localized on the outer surface of microparticles. This is the first report implicating the role of microparticles as a novel carrier of mediators formed in the cells.

Acetylesterase↗

PubMed1996

Prevalence of impaired responsiveness to epinephrine in platelets among Japanese.

The responsiveness of platelets only to epinephrine was markedly impaired in 23/140 (16%) healthy Japanese. The impaired responsiveness was not altered by changes in time and environment. Circulating level of catecholamines did not affect the responsiveness of platelets to epinephrine. A pilot family study indicated a possible familial nature of the defect. 3H methyl-yohimbine binding studies indicated that this defect was due to the decreased number of alpha 2 adrenergic receptor. Despite the defect, the potentiating effect of epinephrine on platelet aggregation stimulated by a low dose of ADP was normal. This abnormality is not apparently associated with any bleeding disorders and the clinical implication is unknown at present. It is, however, essential to acknowledge the prevalence of such defect in pursuing research on platelets stimulated by epinephrine.

Adenosine Diphosphate↗

PubMed1996

Interleukin 6 receptor antibody inhibits muscle atrophy and modulates proteolytic systems in interleukin 6 transgenic mice.

The muscles of IL-6 transgenic mice suffer from atrophy. Experiments were carried out on these transgenic mice to elucidate activation of proteolytic systems in the gastrocnemius muscles and blockage of this activation by treatment with the anti-mouse IL-6 receptor (mIL-6R) antibody. Muscle atrophy observed in 16-wk-old transgenic mice was completely blocked by treatment with the mIL-6R antibody. In association with muscle atrophy, enzymatic activities and mRNA levels of cathepsins (B and L) and mRNA levels of ubiquitins (poly- and mono-ubiquitins) increased, whereas the mRNA level of muscle-specific calpain (calpain 3) decreased. All these changes were completely eliminated by treatment with the mIL-6R antibody. This IL-6 receptor antibody could, therefore, be effective against muscle wasting in sepsis and cancer cachexia, where IL-6 plays an important role.

Animals↗

PubMed1996

Fatal differentiated thyroid cancer.

Thirty-five patients who died of differentiated thyroid cancer were analyzed for factors affecting survival. The neck was the most common initial site of recurrence (62.0%). The lung was the most common metastatic site (56.7%). Major sites associated with death were locoregional recurrence (neck and mediastinum: 48.6%) and bone metastases (22.9%). By univariate analysis, local tumor extension, type of initial surgery, and residual tumor and/or existence of distant metastases at the initial operation were significant factors affecting survival. Stepwise multivariate analysis revealed that invasion of the esophagus and/or carotid artery shortened survival and that multiple surgeries extended survival. Our results suggest that to improve survival in patients with differentiated thyroid cancer, better locoregional control, including multiple surgical resection, is necessary.

Adult↗

PubMed1996

Involvement of protein phosphatase 2A in PKC-independent pathway of neutrophil superoxide generation by fMLP.

We examined the effects of okadaic acid, a protein phosphatase 1 and 2A inhibitor, on superoxide generation in human neutrophils. Superoxide generation induced by fMLP was inhibited by low-dose okadaic acid (10-100 nM), but it had no effect on superoxide synthesis by PMA, and the fMLP-induced rise of the intracellular Ca2+ concentration was not affected by low-dose okadaic acid. These findings suggested that the inhibitory mechanism of okadaic acid might involve PKC-independent and Ca(2+)-independent pathways in fMLP induced NADPH oxidase activation. Both fMLP-stimulated phosphorylation of serine residues in p47phox and its translocation to the plasma membrane were suppressed by low-dose okadaic acid. On the other hand, PMA-induced phosphorylation and translocation of p47phox were not affected by such a low dose of okadaic acid. These findings suggested that fMLP induced phosphorylation of serine residues in p47phox was regulated by protein phosphatase 2A, and its phosphorylation was necessary for translocation and superoxide generation in fMLP-activated human neutrophils.

Calcium↗

PubMed1996

Simultaneous digital imaging analysis of cytosolic calcium and morphological change in platelets activated by surface contact.

The dynamic change of cytoplasmic Ca(2)+ concentration ([Ca(2)+]i) and morphological change were investigated simultaneously by confocal laser scanning microscopy using fluo-3 and by differential interference contrast optics in platelets activated by contact with the following types of surfaces: native glass and glass treated with poly-L-lysine (PLL), fibrinogen (Fg), or von Willebrand factor (vWF). The initial [Ca(2)+]i values just after the surface contact were comparable (approximately 100 nM) among platelets deposited on the four surface types. On the PLL-surface, no morphological change or [Ca(2)+]i elevation was observed. Glass-, Fg-, and vWF-surface adhered platelets showed pseudopod formation and spreading associated with the inhomogeneous [Ca(2)+]i rise. The platelets on the Fg-surface were the most active in terms of [Ca(2)+]i rise and morphological change. During pseudopod formation, the mean [Ca(2)+]i value was maximal and localized high [Ca(2)+]i zones were observed inside pseudopods, as well as in the center of the platelets. After spreading, high [Ca(2)+]i zones still remained in the center of the cell. This new technique enabled simultaneous observation of [Ca(2)+]i and cell shape and we clearly demonstrated a close relationship between [Ca(2)+]i and morphological alterations.

Analog-Digital Conversion↗