Biomedical subjects

N Kurihara

Publications and source records attributed to N Kurihara.

At least 19 recordsLinked to original sources

PubMed2002

Colonic epithelial cell proliferation decreases with increasing levels of serum 25-hydroxy vitamin D.

Epidemiological evidence suggests a potential role for vitamin D in colon cancer prevention. Vitamin D, absorbed from the intestine or derived from solar ultraviolet light, is metabolized in the liver to 25-hydroxyvitamin D (25-OH D(3)). Previous studies examining effects of vitamin D upon carcinogenesis have focused upon the active metabolite 1,25-dihydroxyvitamin D [1,25-(OH)(2) D(3)], which interacts with nuclear vitamin D receptors in several organs. Until recently, the metabolism of 25-OH D(3) to 1,25-(OH)(2) D(3) was believed to occur only in the kidney, but more recent studies have shown that 25-OH D(3) conversion to 1,25-(OH)(2) D(3) can occur in other tissues. We examined the association between fasting levels of 25-OH D(3), 1,25-(OH)(2) D(3), and BsmI polymorphism of the vitamin D receptor (VDR) gene with indices of colonic epithelial cell proliferation and differentiation in a chemoprevention study, after giving vitamin D or calcium and taking rectal biopsies that were incubated with bromodeoxyuridine. Vitamin D receptor polymorphism was determined by genotyping of the 3' BsmI polymorphism in intron eight of the VDR gene. No significant changes in cell proliferation or in differentiation were found in subjects between study start and end. However, fasting serum levels of 25-OH D(3) showed a highly significant decrease with whole crypt labeling index and the size of the proliferative compartment (phi h). There was no correlation between serum levels of 1,25-(OH)(2) D(3) and the proliferative parameters. Calcium supplementation induced a significant effect upon the relationship between serum 25-OH D(3) and rectal epithelial cell labeling index and phi h when studied by covariance analysis without a relationship with 1,25-(OH)(2) D(3) levels. VDR genotype did not influence the effects of serum 25-OH D(3) or serum 1,25-(OH)(2) D(3) levels upon proliferation. These data suggest that there might be a local effect of 25-OH D(3) on colonic epithelial cells through conversion of 25-OH D(3) to 1,25-(OH)(2) D(3). Subsequent studies have demonstrated the presence of 1alpha-hydroxylase mRNA in normal colorectal epithelium and in colorectal cancer. Thus, vitamin D may have an important role in determining the effects of calcium on colorectal epithelial proliferation and may explain some of the discrepancies found previously in studies that examine the direct role of calcium on the colorectal epithelium.

Adult↗

PubMed2002

The proximal form of mural thrombus in aortoiliac occlusive disease using computed tomography.

BACKGROUND: It is important to know the nature of proximal thrombus in patients with aortoiliac occlusive disease (AIOD) when juxtarenal aortic clamping is scheduled. This study was aimed to evaluate the shape and nature of thrombi at several sites of the abdominal aorta in patients with AIOD using enhanced computed tomography (CT). Final judgment was made according to the operative findings. METHODS: Between the years 1999 and 2001, 22 patients, who underwent aortobifemoral bypass, were enrolled. The shape and nature of their thrombi were examined at 4 points (superior mesenteric, suprarenal, juxtarenal and infrarenal arteries at the level of the 2 cm before the renal artery) and 88 slices of CT were examined retrospectively. RESULTS: There was mural thrombus in 31 slices, which could be classified into 4 shapes (crescent-shaped: 10 cases; magatama: 2; wavy: 12; circular: 6). The wavy and circular shaped thrombi were found to be atheromatous. Nine cases (40.9%) on operative findings were atheroma (wavy: 4; circular shaped: 5). The crescent shape might correspond to fibrin thrombus. Atheromatous thrombus clamping near the renal artery was thought to cause microthromboembolism to surrounding organs. CONCLUSIONS: It is recommended that the more proximal aorta or splanchnic arteries should be temporarily clamped during proximal procedures in patients with wavy or circular shaped thrombi at the juxtarenal aorta to prevent kidney or bowel infarction.

Aged↗

PubMed2001

Decreased expression of DNA-dependent protein kinase, a DNA repair protein, during human colon carcinogenesis.

DNA-dependent protein kinase (DNA-PK), consisting of a catalytic subunit (DNA-PKcs) and the Ku70 and Ku86 proteins, participates in the repair of DNA double-strand breaks (DSBs). We assessed its expression immunohistochemically in normal human colon tissue, colon adenomas, colon carcinomas, and normal tissue distant from carcinomas. Normal colonocytes expressed all DNA-PK proteins. Compared with the expression in normal tissue [176.62 +/- 18.56 (the intensity of expression x the percentage of cells expressing this protein), mean + SE], the expression of Ku70 was significantly reduced in adenomas (36.62 +/- 11.09; P < 0.001) and carcinomas (85.68 +/- 15.76; P < 0.01), as was the expression of Ku86 [(113.10 +/- 10.22 versus 41.66 +/- 14.71 in adenomas (P < 0.01) or versus 85.68 +/- 15.76 in carcinomas (P < 0.05)]. The expression of DNA-PKcs was not significantly changed. The marked underexpression of Ku70 and Ku86 starting at the adenoma stage may be crucial to the development of colon cancer.

Adenoma↗

PubMed2001

Osteoclast-stimulating factor interacts with the spinal muscular atrophy gene product to stimulate osteoclast formation.

We have recently identified and cloned an intracellular peptide termed osteoclast-stimulating factor (OSF) that increases osteoclast (OCL) formation and bone resorption through a cellular signal transduction cascade, possibly through its interaction with c-Src or related family members. To further identify participants in the OSF signaling cascade, we used yeast two-hybrid screening with Saccharomyces cerevisiae, and we found that the 40-kDa spinal muscular atrophy disease-determining gene product, survival motor neuron (SMN), interacts with the OSF-Src homology 3 domain. Reverse transcription-polymerase chain reaction analysis of SMN mRNA expression in cells of the OCL lineage demonstrates that expression of the exon 7 splice variant of SMN is restricted to mature OCLs, whereas the unspliced transcript was expressed in OCL precursors as well as mature OCLs. Treatment of murine bone marrow cultures with conditioned media (5% (v/v)) from 293 cells transiently expressing the SMN cDNA significantly increased OCL formation, compared with treatment with conditioned media from mock-transfected cells. Furthermore, OCL-stimulatory activity by OSF or SMN was abolished by antisense constructs to SMN or OSF, respectively. These data confirm the participation of SMN in the OSF-enhanced expression of an OCL stimulator. OSF-SMN interaction may provide more insights into novel cellular signaling mechanisms that may play an important role in congenital bone fractures associated with type I spinal muscular atrophy disease.

Animals↗

PubMed2001

Macrophage inflammatory protein-1alpha is an osteoclastogenic factor in myeloma that is independent of receptor activator of nuclear factor kappaB ligand.

A complementary DNA expression library derived from marrow samples from myeloma patients was recently screened and human macrophage inflammatory protein-1alpha (hMIP-1alpha) was identified as an osteoclastogenic factor expressed in these samples. hMIP-1alpha enhanced osteoclast (OCL) formation in human marrow cultures and by highly purified OCL precursors in a dose-dependent manner (5-200 pg/mL). Furthermore, hMIP-1alpha enhanced OCL formation induced by human interleukin-6 (IL-6), which is produced by marrow stromal cells when they interact with myeloma cells. hMIP-1alpha also enhanced OCL formation induced by parathyroid hormone-related protein (PTHrP) and receptor activator of nuclear factor kappaB ligand (RANKL), factors also implicated in myeloma bone disease. Time-course studies revealed that the hMIP-1alpha acted during the last 2 weeks of the 3-week culture period. Reverse transcription-polymerase chain reaction analysis showed that the chemokine receptors for hMIP-1alpha (CCR1 and CCR5) were expressed by human bone marrow and highly purified early OCL precursors. Furthermore, hMIP-1alpha did not increase expression of RANKL. These data demonstrate that hMIP-1alpha is an osteoclastogenic factor that appears to act directly on human OCL progenitors and acts at the later stages of OCL differentiation. These data further suggest that in patients with myeloma, MIP-1alpha produced by myeloma cells, in combination with RANKL and IL-6 that are produced by marrow stromal cells in response to myeloma cells, enhances OCL formation through their combined effects on OCL precursors. (Blood. 2001;97:3349-3353)

Bone Marrow Cells↗

PubMed2001

Prenatal MR findings in a case of aneurysm of the vein of Galen.

We describe a case of aneurysm of the vein of Galen (AVG), which was diagnosed by intrauterine US, MRI and MRA. The baby girl was born at 35 weeks' gestation. She had severe clinical symptoms at birth and died at 29 h of age from intractable congestive heart failure. Intrauterine US detected an intracranial aneurysm and cardiomegaly due to excessive arteriovenous shunting. Intrauterine MRI (SSFSE) confirmed the diagnosis of AVG, and intrauterine MRA (2D-TOF) successfully demonstrated the anatomical structure of the AVG. MRA may be a useful additional sequence to evaluate AVG, and 2D-TOF is thought to be an appropriate technique for scanning fetal AVG.

Adult↗

PubMed2001

IQGAP1, a negative regulator of cell-cell adhesion, is upregulated by gene amplification at 15q26 in gastric cancer cell lines HSC39 and 40A.

Our previous comparative genomic hybridization (CGH) study revealed a novel amplified region at 15q26 in two cell lines established from diffuse types of gastric cancer (GC). In this amplified region, FES and IGF1R, known targets on 15q26, were located telomeric to the amplicon in the two cell lines, HSC39 and 40A, suggesting that another tumor-associated gene exists in this region. While screening expressed sequence tags (ESTs) for novel genes in this region, we identified the IQGAP1 amplification. IQGAP1 has been reported to encode a ras GAP-related protein, and its interaction with cadherin and/or beta-catenin induces a dissociation of beta-catenin from the cadherin-catenin complex, one of the mechanisms for cell-cell adhesion. Northern and Western blot analyses revealed that amplification of this gene was accompanied by corresponding increases in mRNA and protein expression. Moreover, immunocytochemical staining showed that overexpressed IQGAP1 accumulated at the membrane, suggesting its colocalization with beta-catenin. Taken together, these findings suggest that IQGAP1 may be one of the target genes in the 15q26 amplicon correlated with a malignant phenotype of gastric cancer cells, such as diffuse and invasive characteristics, through the disruption of E-cadherin-mediated cell-cell adhesion.

Carrier Proteins↗

PubMed2001

Paget's disease of bone: a disease of the osteoclast.

Paget's disease is a chronic focal disease of the skeleton that affects up to 2-3% of the population over the age of 60 years. There is a genetic predisposition for Paget's disease, with one predisposition locus identified on chromosome 18q-21-22. Osteoclasts and osteoclast precursors from Paget's patients are abnormal and appear hyperresponsive to 1,25(OH)2D3 and RANK ligand and contain paramyxoviral transcripts (Fig. 1). The basis for the abnormalities detected in Paget's disease and the role that the paramyxoviruses may play in this disease are still unclear.

Humans↗

PubMed2001

Osteoclasts formed by measles virus-infected osteoclast precursors from hCD46 transgenic mice express characteristics of pagetic osteoclasts.

Pagetic osteoclasts (OCLs) are abnormal in size and contain paramyxoviral-like nuclear inclusions that cross-react with antibodies to measles virus (MV). However, the role that MV infection plays in Paget's disease is unknown, because no animal model of Paget's disease is available. Therefore, we targeted a cellular MV receptor, human CD46 (hCD46), to cells in the OCL lineage in transgenic mice using the mouse tartrate-resistant acid phosphatase (TRAP) gene promoter. In vitro infection of OCL precursors from hCD46 transgenic mice with MV significantly increased OCL formation in bone marrow cultures. The numbers of TRAP-positive mononuclear cells and CFU-GM, the earliest identifiable OCL precursor, were also significantly increased. MV-infected OCLs formed from hCD46 marrow were increased in size, contained markedly increased numbers of nuclei, and had increased bone-resorbing capacity per OCL compared with OCLs formed from marrow of nontransgenic littermates. Furthermore, IL-6 and 24-hydroxylase messenger RNA expression levels were increased in MV-infected hCD46 transgenic mouse bone marrow cultures. Treatment of MV-infected hCD46 marrow cultures with a neutralizing antibody to IL-6 blocked the increased OCL formation seen in these cultures. These data demonstrate that MV infection of OCL precursors results in OCLs that have many features of pagetic OCLs, that the enhanced OCL formation is in part mediated by increased IL-6 expression induced by MV infection, and suggest that the hCD46 transgenic mouse may be a useful model for examining the effects of MV infection on OCL formation in vivo.

Acid Phosphatase↗

PubMed2001

Osteoclast inhibitory peptide 2 inhibits osteoclast formation via its C-terminal fragment.

Osteoclast inhibitory peptide 2 (OIP-2) is a novel autocrine/paracrine factor produced by osteoclasts (OCLs) that inhibits bone resorption and OCL formation in vitro and in vivo. It is identical to the asparaginyl endopeptidase legumain. During maturation of OIP-2, a signal peptide and a 17-kDa C-terminal fragment (CTF) are cleaved to produce the mature enzyme. To determine if enzyme activity is required for inhibition of OCL formation or if only the CTF is responsible for these effects, we synthesized His-tagged complementary DNA (cDNA) constructs for the CTF of OIP-2, the proform of OIP-2, and the "mature enzyme" form of OIP-2. The proform or the CTF portion of OIP-2 inhibited OCL formation in a dose-dependent manner in murine bone marrow cultures stimulated with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. The mature form of OIP-2, which was enzymatically active, did not inhibit OCL formation. In addition, OIP-2 inhibited OCL formation in cultures of highly purified human OCL precursor cells or RAW264.7 cells stimulated with 10 ng/ml of receptor activator of NF-kappaB (RANK) ligand. Binding studies with His-tagged OIP-2 showed expression of a putative OIP-2 receptor on RAW264.7 cells treated with RANK ligand for 4 days and human marrow cultures treated with 1,25(OH)2D3 for 3 weeks. These data show that the CTF of OIP-2, rather than the mature enzyme, mediates the inhibitory effects of OIP-2 through a putative receptor on OCL precursors.

Animals↗

PubMed2000

CFU-GM-derived cells form osteoclasts at a very high efficiency.

The granulocyte-macrophage progenitor (CFU-GM) is a multipotent cell that can differentiate to osteoclasts (OCLs), macrophages, or granulocytes. However, the relative potential of CFU-GM to efficiently form OCLs is unknown. In this report we demonstrate that granulocyte-macrophage colony-forming unit (CFU-GM)-derived cells represent an easily obtainable highly purified source of human OCL precursors that form OCLs at very high efficiency (greater than 90%) when cultured with RANK ligand (RANKL), macrophage colony-stimulating factor (M-CSF), and dexamethasone. The OCLs that formed have high bone-resorbing activity and form multiple resorption lacunae per OCL on dentin slices. Similarly, murine marrow-derived CFU-GM also formed OCLs at a high efficiency (>80%) when treated with RANKL, M-CSF, and dexamethasone. In contrast, more committed macrophage colony-forming unit (CFU-M)-derived cells form few OCLs under these conditions.

Animals↗

PubMed2000

CD44 is a potential target of amplification within the 11p13 amplicon detected in gastric cancer cell lines.

Classical cytogenetic approaches have revealed many of the chromosomal aberrations that may occur in gastric cancers (GC), although few alterations of specific genes have been identified so far. Genes that affect progression of this disease need to be identified if clinicians are to achieve optimal management of patients with GC. As the first step toward the cloning of gene(s) that may be involved in gastric carcinogenesis, we examined 25 GC cell lines for aberrations in DNA copy number to detect chromosomal gains and losses, as well as gene amplifications, by comparative genomic hybridization (CGH). Our CGH study revealed high-level amplifications in chromosomal regions that had been well defined in GC but also in sites that had not, including 3p24, 5p15, 11p11.2-14, 13q34, 15q26, Xp24, and Xq26-28. The minimal common region at 11p13, within the 11p11.2-14 amplicon, harbors the CD44 gene. Northern and Western blot analyses showed that an alternatively spliced form of CD44, with variant exons 8-10 (CD44E), was overexpressed in all cell lines bearing the 11p13 amplicon. However, cell adhesion activity was no greater in these lines than in cell lines without amplifications at the CD44 locus, suggesting that the major property of upregulated CD44 in these cases might be to transduce signals critically associated with growth and proliferation of the tumor cells.

Blotting, Northern↗

PubMed2000

Investigation of hydrocephalus with three-dimensional constructive interference in steady state MRI.

We report four patients with various types of hydrocephalus in whom constructive interference in steady state (CISS) MRI disclosed the cause of the hydrocephalus. The imaging clearly delineated an abnormal contour of the ventricular system and intraventricular septa, essential information for surgical planning, including endoscopic surgery. Postoperative CISS images were useful for showing not only regression of hydrocephalus but also the patency of small fenestrations.

Aged↗

PubMed2000

Matrix metalloproteinase expression in cultured human gastric wall fibroblasts--interactions with Helicobacter pylori isolated from patients with ulcers.

BACKGROUND: Matrix metalloproteinases (MMPs), enzymes capable of degrading collagens and other extracellular matrix components, have been implicated in gastric ulcer formation. However, the effect on MMP expression of Helicobacter pylori, also implicated in these lesions, has not been studied to our knowledge. AIM: To seek links between H. pylori and MMP expression likely to affect gastric ulcer formation. After fibroblasts from human gastric wall were cocultured with H. pylori. concentrations of MMP-1 and -2 in the medium were determined by enzyme-linked immunosorbent assays. RESULTS: Whereas MMP-1 was not detected in media from fibroblasts or H. pylori culture alone, MMP-1 was detected in cocultures (P<0.01). Similar amounts of MMP-2 were detected in medium from fibroblasts cultured alone and with H. pylori. No MMP-2 production by H. pylori cultured alone was detected. CONCLUSIONS: MMP-1 appears to be important in gastric ulcer pathogenesis, and MMP-1 induction by H. pylori may impede gastric ulcer healing.

Cells, Cultured↗

PubMed2000

Nonrandom chromosomal imbalances in esophageal squamous cell carcinoma cell lines: possible involvement of the ATF3 and CENPF genes in the 1q32 amplicon.

Using comparative genomic hybridization (CGH), we investigated copy number aberrations in 29 esophageal squamous cell carcinoma (ESC) cell lines. All lines displayed numerous chromosome imbalances. The most frequent losses were observed on chromosome 18q (65.5%), Xp (48. 3%), 3p (44.8%), 4q (44.8%), 8p (41.4%), 11q23 - 25 (34.5%) and 4p (27.6%), whereas the most common copy number gains were noted at 8q (86.2%), 3q (82.8%), 5p (69%), 7p (69%), 20q (65.5%), 9q (55.2%), 11q (55.2%), 1q (48.3%), Xq (44.8%) and 18p (37.9%). High-level gains (HLGs) were detected at 3q26 (9 cases), 8q23 (6 cases), 5p14 - 15 (6 cases), 18p11.2 - 11.3 (6 cases), 3q27 - 28 (5 cases), 5p13 (3 cases), 7p14 - 15 (3 cases), 20q12 - 13 (3 cases), 11q13 (3 cases), 14q21 (2 cases), 20p11.2 (2 cases), 13q32 (2 case), and 1q32 (1 case). Among them, HLGs of 1q32 have been reported in other types of cancer, including glioblastoma and breast cancers. We successfully narrowed down the smallest common amplicon involving 1q-gain to the genomic segment between D1S414 and D1S2860 by fluorescence in situ hybridization (FISH). Southern and northern blot analysis clearly demonstrated that ATF3, human activating transcription factor-3 and CENPF, centromere protein F, mapped within this region, were significantly amplified and over-expressed in 1q32 amplicon.

Activating Transcription Factor 3↗

PubMed2000

Molecular cytogenetic analysis of 17 renal cancer cell lines: increased copy number at 5q31-33 in cell lines from nonpapillary carcinomas.

Comparative genomic hybridization (CGH) was used to screen for genomic imbalances in cell lines derived from 13 nonpapillary renal-cell carcinomas (RCCs), two papillary RCCs, one renal squamous-cell carcinoma, and one transitional-cell carcinoma of the renal pelvis. Aberrations were found in all 17 lines. The most frequent changes in nonpapillary RCC cell lines were gains of 5q (85%), 7q (69%), 8q (69%) and 1q (54%) and losses of 3p (92%), 8p (77%), 4q (62%) and 14q (54%). High-level gains (HLGs) were detected at 4q12, 5p, 5q23-33, 7q22-qter, 8q23-24, 10q21-qter, 12p and 12q13-22. By means of fluorescence in situ hybridization (FISH) we narrowed the smallest common region involving 5q gains to the genomic segment between D5S642 and D5S673, and found that the HLG at 4q12 possibly involved amplifications of c-kit and PDGFRA. Two papillary RCC cell lines showed gains of entire chromosomes 7, 12 and 17. The CGH data reported here should help to facilitate the choice of individual renal-tumor cell lines for exploring target genes in regions of interest.

Adult↗

PubMed2000

Osteoclasts expressing the measles virus nucleocapsid gene display a pagetic phenotype.

Osteoclasts (OCLs) in Paget's disease are markedly increased in number and size, have increased numbers of nuclei per multinucleated cell, and demonstrate increased resorption capacity and increased sensitivity to 1,25-(OH)(2)D(3), the active form of vitamin D. These cells also contain nuclear inclusions, reminiscent of those seen in paramyxovirus-infected cells, which cross-react with antibodies to measles virus nucleocapsid (MVNP) antigen. To elucidate the role of MV in the abnormal OCL phenotype of Paget's disease, we transduced normal OCL precursors with retroviral vectors expressing MVNP and the MV matrix (MVM) genes. The transduced cells were then cultured with 1,25-(OH)(2)D(3) for14 or 21 days to induce formation of OCL-like multinucleated cells. The MVNP-transduced cells formed increased numbers of multinucleated cells, which contained many more nuclei and had increased resorption capacity compared with multinucleated cells derived from empty vector-transduced (EV-transduced) and MVM-transduced or normal bone marrow cells. Furthermore, MVNP-transduced cells showed increased sensitivity to 1, 25-(OH)(2)D(3), and formed OCLs at concentrations of 1, 25-(OH)(2)D(3) that were 1 log lower than that required for normal, EV-transduced, or MVM-transduced cells. These results demonstrate that expression of the MVNP gene in normal OCL precursors stimulates OCL formation and induces OCLs that express a phenotype similar to that of pagetic OCLs. These results support a potential pathophysiologic role for MV infection in the abnormal OCL activity and morphology that are characteristic of pagetic OCLs.

Bone Marrow Cells↗

PubMed2000

Enhanced RANK ligand expression and responsivity of bone marrow cells in Paget's disease of bone.

Paget's disease is characterized by highly localized areas of increased osteoclast (OCL) activity. This suggests that the microenvironment in pagetic lesions is highly osteoclastogenic, or that OCL precursors in these lesions are hyperresponsive to osteoclastogenic factors (or both). To examine these possibilities, we compared RANK ligand (RANKL) mRNA expression in a marrow stromal cell line developed from a pagetic lesion (PSV10) with that in a normal stromal cell line (Saka), and expression in marrow samples from affected bones of Paget's patients with that in normal marrow. RANKL mRNA was increased in PSV10 cells and pagetic marrow compared with Saka cells and normal marrow, and was also increased in marrow from affected bones compared with uninvolved bones from Paget's patients. Furthermore, pagetic marrow cells formed OCLs at much lower RANKL concentrations than did normal marrow. Anti-IL-6 decreased the RANKL responsivity of pagetic marrow to normal levels, whereas addition of IL-6 to normal marrow enhanced RANKL responsivity. Thus, RANKL expression and responsivity is increased in pagetic lesions, in part mediated by IL-6. These data suggest that the combination of enhanced expression of RANKL in affected bones and increased RANKL sensitivity of pagetic OCL precursors may contribute to the elevated numbers of OCLs in Paget's disease.

Antibodies↗