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K Moriyama

Publications and source records attributed to K Moriyama.

At least 37 records · Page 2Linked to original sources
PubMed2001

Induction of the expression of SCF in mouse by lethal irradiation.

To clarify what kinds of cytokines are actually contributing to proliferation of hemopoietic stem cells in vivo after lethal irradiation, we have investigated the expression of some cytokines by RT-PCR method. Above all, expression of the SCF was increased significantly in the bone marrow cells soon after lethal irradiation in both the Sca-1 (+) bone marrow cells injected and non-injected mice. The day 6 serum from the lethally irradiated mice could support the proliferation of the Sca-1 (+) bone marrow cells, even though the serum from normal mice could not. The quantification analyses have revealed the increase of the amounts of IL-6 and flt3-ligand in their serum, but not significant increase of the amount of SCF. Precise PCR analysis has revealed that the cell surface associated form of SCF was significantly induced in the bone marrow after lethal irradiation. These data indicate that the cell surface form of SCF mainly promotes the proliferation of hemopoietic stem cells with some soluble cytokines under sever lack of hemopoietic stem cells in vivo caused by lethal irradiation and also suggest the importance of direct cell-to-cell interaction on proliferation of hematopoietic stem cells in vivo.

Animals↗
PubMed2001

[A case of vaginal implantation of transitional cell carcinoma of the bladder].

An 82-year-old female presented with asymptomatic gross hematuria in June 1997. Urethrocystoscopy revealed a multiple papillary tumor of the bladder and posterior urethra. Histology of the punch biopsy specimens of the tumor revealed transitional cell carcinoma (TCC), grade 2 (G2). CT scan showed no distant metastasis and extravesical invasion. The patient was treated by intravesical instillation of adriamycin (ADM), drip infusion of low dose cisplatin (CDDP) and irradiation of the bladder. As the treatment caused a significant tumor shrinkage, transurethral resection of the tumor was performed. Histologically, the tumor revealed no invasion to the muscular layer of the bladder. In April 1998 she noticed genital bleeding, and a multiple papillary tumor was found on the vaginal wall. Histology of punch biopsy specimens of the vaginal tumor showed non-invasive TCC, G2. MRI and specimens of all layer needle biopsy showed no infiltration outside the bladder wall and the vaginal wall. Irradiation of the cavity of the vagina and uterus was made under the diagnosis of superficial vaginal TCC. We assume that vaginal implantation via irrigating fluid or urine has occurred.

Aged↗
PubMed2000

Mechanism for bone invasion of oral cancer cells mediated by interleukin-6 in vitro and in vivo.

BACKGROUND: Osteoclastic bone resorption is an important step in bone invasion in several malignancies. Although interleukin (IL)-6 accelerates osteoclastic bone resorption, it remains unclear whether IL-6 may be involved in bone invasion of oral cancer. METHODS: The pit formation assay with calf femur-derived bone slices was performed to examine the bone-resorbing activity of osteoclasts and cancer cells. The chemotaxis activity of the culture media was analyzed by the use of Boyden chamber technique. Nude mice, which were inoculated with IL-6-producing oral cancer cells into masseter, were treated with anti-IL-6 neutralizing antibody, and mandibular-bone invasion of the cells was assessed. RESULTS: BHY, a bone-invasive oral cancer cell line, but not HNT, a noninvasive cell line, produced large amounts of IL-6. In a pit formation assay, addition of conditioned medium (CM) derived from BHY but not HNT increased osteoclastic bone resorption, and the effects were inhibited by anti-IL-6 antibody. BHY-secreted IL-6 showed significant chemotaxis activity for osteoclasts. Of note, CM from the cocultivation of osteoclasts and BHY markedly enhanced the cancer cell migration, and the chemotaxis activity was significantly reduced when anti-IL-6 antibody was added into the coculture and then CM were collected, but not when the antibody was added into the CM after they were collected. Furthermore, treatment with anti-IL-6 antibody almost completely inhibited mandibular bone invasion of BHY in nude mice. CONCLUSIONS: These results strongly suggest that IL-6 secreted by oral cancer cells plays a significant role in bone invasion.

Animals↗
PubMed2000

Structural requirement of carboxyl-terminal globular domains of laminin alpha 3 chain for promotion of rapid cell adhesion and migration by laminin-5.

The basement membrane protein laminin-5, a heterotrimer of laminin alpha3, beta3, and gamma2 chains, potently promotes cellular adhesion and motility. It has been supposed that the carboxyl-terminal globular region of the alpha3 chain consisting of five distinct domains (G1 to G5) is important for its interaction with integrins. To clarify the function of each G domain, we transfected cDNAs for the full-length (wild type (WT)) and five deletion derivatives (DeltaGs) of the alpha3 chain into human fibrosarcoma cell line HT1080, which expressed and secreted the laminin beta3 and gamma2 chains but not the alpha3 chain. The transfectants with the alpha3 chain cDNAs lacking G5 (DeltaG(5)), G4-5 (DeltaG(4-5)), G3-5 (DeltaG(3-5)), and G2-5 (DeltaG(2-5)) secreted laminin-5 variants at levels comparable to that with WT cDNA. However, the transfectant with the cDNA without any G domains (DeltaG(1-5)) secreted little laminin-5, suggesting that the G domains are essential for the efficient assembly and secretion of the heterotrimer alpha3beta3gamma2. The transfectants with WT, DeltaG(5), and DeltaG(4-5) cDNAs survived in serum-free medium longer than those with DeltaG(3-5), DeltaG(2-5), and DeltaG(1-5) cDNAs. The transfectants with WT, DeltaG(5), and DeltaG(4-5) cDNAs secreted apparently the same size of laminin-5, which lacked G4 and G5 due to proteolytic cleavage between G3 and G4, and these laminin-5 forms potently promoted integrin alpha(3)beta(1)-dependent cell adhesion and migration. However, the laminin-5 forms of DeltaG(3-5) and DeltaG(2-5) hardly promoted the cell adhesion and motility. These findings demonstrate that the G3 domain, but not the G4 and G5 domains, of the alpha3 chain is essential for the potent promotion of cell adhesion and motility by laminin-5.

Cell Adhesion↗
PubMed2000

Synthesis of mRNAs for cathepsins L and K during development of the rat mandibular condylar cartilage.

Cathepsins are cysteine proteinase family members which are known to degrade proteoglycan and collagen, components of several extracellular matrices. Their functions in the condylar cartilage during skeletal development have not yet been fully clarified. In this study, we investigated the mRNA expression of cathepsins L and K in the growing rat mandibular condylar cartilage, as compared to that in the rat long bone cartilage, by in situ hybridization, reverse transcription polymerase chain reaction (RT-PCR) and Southern blotting analysis. In the condylar cartilage, cathepsin L mRNA expression was widely observed throughout the zones of maturative and hypertrophic chondrocytes at embryonic day (E) 17 and postnatal day (P) 1. The signal was restricted to maturative and upper hypertrophic chondrocytes at P7, and finally it became undetectable by P28. In the long bone cartilage, cathepsin L was not expressed in the chondrocytes at any stage. Cathepsin K mRNA was not, however, detected either in the mandibular condylar cartilage cells or in the long bone cartilage cells but it was selectively detected in osteoclasts in calcified cartilage and bone in both tissues. RT-PCR also showed a similar mRNA expression pattern of cathepsins L and K. These results indicate that cathepsins L and K may be involved in the skeletal development of both the long bone and the mandibular condyle. Furthermore, cathepsin L may play an important role in the degradation of the cartilaginous extracellular matrix in maturative and hypertrophic cell layers during successive developmental stages of the mandibular condyle.

Animals↗
PubMed2000

Severe destructive autoimmune lesions with aging in murine Sjögren's syndrome through Fas-mediated apoptosis.

When we evaluated the age-associated changes in autoimmune exocrinopathy in a NFS/sld murine model for primary Sjögren's syndrome (SS), severe destructive autoimmune lesions developed in the salivary and lacrimal glands in the aged mice, compared with those observed in the younger model. We detected a decreased secretion of saliva and tear flow in the aged group. A significant increase of TUNEL(+)-apoptotic epithelial duct cells in the salivary glands was detected in the aged SS animal model. A higher proportion of mouse salivary gland cells bearing Fas was found in the aged group, whereas no significant changes were seen on tissue-infiltrating CD4(+) T cells bearing FasL in the salivary glands from young and aged mice. We detected an increased cleavage product of organ-specific autoantigen, 120-kd alpha-fodrin, in the aged salivary gland tissues on immunoblotting, and an increase in serum autoantibody production against 120-kd alpha-fodrin by enzyme-linked immunosorbent assay. An increase in the proliferative response of splenic T cells against organ-specific autoantigen was observed, whereas nonspecific concanavalin A responsiveness was decreased in the aged mice. In addition, a decrease in Fas expression was found on splenic CD4(+) T cells in the aged mice, and anti-Fas mAb-stimulated apoptosis was down-regulated on CD4(+) T cells. These results indicate that age-associated dysregulation of CD4(+) T cells may play a crucial role on acceleration of organ-specific autoimmune lesions in a murine model for primary SS through Fas-mediated apoptosis.

Aging↗
PubMed2000

Expression of cathepsin K mRNA during experimental tooth movement in rat as revealed by in situ hybridization.

The expression of cathepsin K. a novel collagenolytic enzyme specifically expressed in osteoclasts, was investigated in the rat maxillary dentoalveolar unit during experimental tooth movement by in situ hybridization histochemistry with a non-radioisotopic cRNA probe for rat cathepsin K. Orthodontic elastics were inserted into the interproximal space between the maxillary first and second molars of 7-week-old male SD rats according to Waldo's method and sections prepared from tissues obtained at 12 hr, 1, 2, 3, 4, 7, and 12 days after orthodontic force application. Cathepsin K mRNA expression was detected in the mono- and multinuclear osteoclasts on the pressure side of the alveolar bone at 12 hr after force application, and the distribution and number of cathepsin K mRNA-positive osteoclasts increased time-dependently on the pressure side. At 3-4 days, a marked increase in cathepsin K mRNA-positive osteoclasts was found not only on the pressure side but also on the tension side of the alveolar bone in response to tooth movement. At 7-12 days, the cathepsin K mRNA-positive osteoclasts on both sides had disappeared. These findings suggest that the recruitment of osteoclasts on the pressure side begins during the initial stage of orthodontic tooth movement and the site-specific early induction of cathepsin K mRNA may cause an imbalance in the relative resorption activities on the pressure and tension side incident to such movement.

Alveolar Process↗
PubMed2000

Retrovirus-specific random mutagenesis by a nucleoside 5'-triphosphate analogue, PTP.

In a retrovirus replication model system, which consists of in vitro transcription and reverse transcription cycles, 6-(beta-D-ribofuranosyl)-3,4- dihydro-8H-pyrimido[4,5-c][1,2]oxazin-7-one-5'-triphosphate (PTP) induced highly efficient random mutations and this was due to the ambiguous incorporation of PTP by RNA polymerases. The types of mutations were mainly C-to-U or U-to-C transition mutations and the frequency was about 4 x 10(-2)/nucleotide during four cycles of the replication. Since a high mutation rate is harmful to species, PTP may be new candidate for anti-retroviral drugs. N4-aminoCTP and N4-hydroxyCTP were also incorporated ambiguously by RNA polymerase. These compounds may have a potential to induce mutation by the same mechanism as PTP.

Mutagenesis↗
PubMed2000

[Metachronous bilateral primary malignant lymphoma of the testis: a case report].

A 72-year-old man was referred to our department with the chief complaint of painless swelling of the left scrotum in May 1997. Left high orchiectomy was performed under the diagnosis of primary testicular tumor. Histological findings revealed non-Hodgkin's lymphoma (NHL) of diffuse, mixed type, B cells. No evidence of tumors in any other site was detected by further examinations. About 3 years and a month earlier, he had undergone right high orchiectomy and postoperative radiotherapy (inverted Y irradiation) and chemotherapy (CHOP 5 cycles) for a right testicular tumor whose histological findings were NHL of diffuse, large cell type, B cells. Metachronous bilateral primary malignant lymphoma of the testis is very rare and we discussed each tumor origin by using IgH gene (IgJHDNA) rearrangement as a tumor specific marker of B cell lineage malignant lymphoma. We discussed the clonality of IgJHDNA rearrangement using polymerase chain reaction (PCR) in each paraffin fragment diagnosed pathologically as NHL of B cell origin.

Aged↗
PubMed2000

Histological reaction of auditory bulla bone to synthetic auditory ossicle (Apaceram) in rats.

To investigate the biocompatibility of a synthetic auditory ossicle to host bone, small thin Apaceram disks composed of dense hydroxyapatite were implanted under the periosteum of the left auditory bulla in 32 rats for periods ranging from 1 day to 270 days. A sham operation performed on 10 rats served as a control. Decalcified histological sections stained with hematoxylin and eosin were observed using light microscopy. The experiment showed: 1) a time-dependent mature fibrous connective tissue surrounding the Apaceram disk, 2) no evidence of inflammatory reaction caused by the implant from 90 days after implantation until the end of the experiment, 3) no evidence of osteolysis by osteoclasts caused by the implant, and 4) direct contact of bone to the implant on the bone-disk interface at 180 and 270 days after implantation. The findings suggest that Apaceram has a high degree of implant biocompatibility, making it a satisfactory substitute biomaterial for otological reconstructive surgeries.

Animals↗
PubMed2000

Preservation of rat palatal scar tissue myofibroblasts in organ culture.

In order to modulate palatal scar tissue, especially its myofibroblastic component, there is a pressing need for an in vitro model of this tissue. In the present, study we established an organ culture model of the rat palatal scar tissue. After excision of palatal mucoperiosteum, explants from the developing immature scar tissue and from the normal palatal mucosa were used to observe myofibroblasts in vivo and their maintenance in organ culture. Explants were cultured at the gas-liquid interface in serum-free Waymouth's MB 752/1 medium and in a humid atmosphere containing 55% O2/5% CO2 in air at 37 degrees C for 3 days. Viability of the cultured explants was evaluated with morphological and histological criteria and BrdU incorporation. After organ culture, the scar tissue showed good preservation of the in vivo histology. The myofibroblasts and smooth muscle cells of the cultured scar tissues showed continuous expression of alpha-smooth muscle actin (alpha-SMA), mimicking the in vivo situation. In the normal tissues, only smooth muscle cells of the blood vessels expressed alpha-SMA. These results demonstrate that the established model provides a useful in vitro experimental tool for investigating the palatal scar tissue in general and its myofibroblasts in particular.

Actins↗
PubMed1999

Two activities of cofilin, severing and accelerating directional depolymerization of actin filaments, are affected differentially by mutations around the actin-binding helix.

The biochemical activities of cofilin are controversial. We demonstrated that porcine cofilin severs actin filaments and accelerates monomer release at the pointed ends. At pH 7.1, 0.8 microM cofilin cut filaments (2.2 microM actin) about every 290 subunits and increased the depolymerization rate 6.4-fold. A kink in the major alpha-helix of cofilin is thought to constitute a contact site for actin. Side chain hydroxyl groups of Ser119, Ser120 and Tyr82 in cofilin form hydrogen bonds with main chain carbonyl moieties from the helix, causing the kink. We eliminated side chain hydroxyls by Ser-->Ala and/or Tyr-->Phe mutagenesis. Severing and depolymerization-enhancing activities were reduced dramatically in an Ala120 mutant, whereas the latter was decreased in a Phe82 mutant with a relatively small effect on severing, suggesting different structural bases for the two activities of cofilin. The Ala120-equivalent mutation in yeast cofilin affected cell growth, whereas that of the Phe82-equivalent had no effect in yeast. These results indicate the physiological significance of the severing activity of cofilin that is brought about by the kink in the helix.

Actin Depolymerizing Factors↗
PubMed1999

Overexpression of laminin gamma2 chain monomer in invading gastric carcinoma cells.

Laminin (LN)-5, a heterotrimer of alpha3, beta3, and gamma2 chains, has been suggested to be involved in tumor cell invasion. The present immunohistochemical study investigated the distribution of the LN gamma2 chain in 48 different human gastric adenocarcinomas. The immunohistochemical analysis showed two distinct patterns of LN gamma2 chain expression: (a) extracellular deposition; and (b) cytoplasmic accumulation. The extracellular deposition of the LN gamma2 chain was typically observed at neoplastic basement membranes of well-differentiated adenocarcinomas. The immunoreactivity was continuous along tumor basement membranes in these tumors but was irregular and diffuse in poorly differentiated carcinomas. These tumor cells coexpressed the LN alpha3 and beta3 chains, suggesting that the LN gamma2 chain was deposited as the LN-5 complex. In contrast, tumor cells at the invading fronts showed strong cytoplasmic staining for the LN gamma2 chain without any detectable signal for the LN alpha3 or beta3 chain in both well- and poorly differentiated carcinomas. On the other hand, in vitro analysis by two-dimensional SDS-PAGE demonstrated that human gastric carcinoma cells secrete a high level of LN gamma2 chain monomer in addition to the LN-5 complex into culture medium. These results indicate that the LN gamma2 chain can be secreted as a single subunit and might be involved in tumor cell invasion.

Adenocarcinoma↗