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Biomedical subjects

M Morimatsu

Publications and source records attributed to M Morimatsu.

At least 19 recordsLinked to original sources
PubMed2001

Genomic organization, chromosomal localization, and promoter analysis of the mouse Mail gene.

The Mail (molecule possessing ankyrin repeats induced by lipopolysaccharide) protein is a member of the IkappaB family. It has six ankyrin repeats that are conserved in other IkappaB proteins, such as IkappaB-alpha and Bcl-3. Mail mRNA expression is induced rapidly following lipopolysaccharide (LPS) injection, most notably in the spleen, lung, and lymph nodes of mice, where immune cells, such as lymphocytes and macrophages, are abundant. In this study, we cloned and characterized the Mail gene. The isolated genomic clones span approximately 30 kb and encompass the entire gene. Comparisons with Mail cDNA revealed that the Mail gene consists of 14 exons. Several splice junctions encoding ankyrin repeats are conserved among Mail and other IkappaB family genes. Southern hybridization showed that Mail is a single-copy gene. Using fluorescence in situ hybridization analysis, mouse and rat Mail genes were mapped to Chromosome (Chr) 16C1.2-C1.3 and Chr 11q21.1, respectively. Primer extension determined the transcription start site of Mail. Sequence analysis of the proximal promoter region revealed the presence of a TATA box and putative transcription factor-binding sites, such as those for NF-kappaB and NF-IL6. This region is sufficient to drive high-level reporter gene expression in LPS-stimulated transfected cells.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Ectopic expression of Smad7 inhibits transforming growth factor-beta responses in vascular smooth muscle cells.

Vascular injury stimulates the cytokine-growth factor network in the vascular wall, including transforming growth factor-beta (TGF-beta). Reportedly, the intracellular signaling of TGF-beta is mediated by Smad proteins. We tested the effects of the ectopic expression of inhibitory Smads in cultured rat smooth muscle cells (SMC) to identify the role of TGF-beta/Smad signaling on the phenotypic modulation of SMC. The cells exposed to human recombinant TGF-beta1 (10 ng/ml) were stimulated Smad2 phosphorylation. Infection with the replication-deficient adenovirus vector expressing Smad7, but not bacterial beta-galactosidase or Smad6, was found to inhibit TGF-beta-induced Smad2 phosphorylation in a dose-dependent manner. TGF-beta suppressed the serum-induced proliferation of SMC from 36.3% to 51.0% (p<0.01), as measured by hand-counting, and this inhibition was attenuated by the ectopic expression of Smad7 (from 30.7% to 74.8% of the reduction of TGF-beta-response, p<0.05), but not Smad6. A BrdU incorporation assay also showed that TGF-beta-mediated growth inhibition was attenuated by exogenous Smad7 and that this inhibition can be reversed by an additional expression of exogenous Smad2. TGF-beta increased the expression of alpha-smooth muscle actin and myosin heavy chain by 1.3-fold and 1.6-fold in comparison to the control, respectively, and these increases were attenuated by exogenous Smad7, but not Smad6. Our data indicate that Smads mediate TGF-beta responses on SMC phenotypes. Smad7, but not Smad6, may specifically act as an inhibitor of TGF-beta responses.

Animals↗
PubMed2001

A novel serum chitinase that is expressed in bovine liver.

Chitinases are ubiquitous chitin-fragmenting hydrolases. They are synthesized by a vast array of organisms, including those not composed of chitin. Here, we describe a novel serum chitinase (chitin-binding protein b04, CBPb04), which is expressed in bovine liver. Although CBPb04 is secreted as an endocrine chitinase, it shows higher homology with human gastrointestinal tract exocrine chitinase (AMCase) than with macrophage endocrine chitinase (human chitotriosidase). This suggests that cows have a specific defense against chitin-containing microorganisms. CBPb04 mRNA is expressed in hepatocytes. This is the first report of a hepatogenic mammalian chitinase.

Amino Acid Sequence↗
PubMed2001

Changes in sodium or glucose filtration rate modulate expression of glucose transporters in renal proximal tubular cells of rat.

Renal glucose reabsorption is mediated by luminal sodium-glucose cotransporters (SGLTs) and basolateral facilitative glucose transporters (GLUTs). The modulators of these transporters are not known, and their substrates glucose and Na+ are potential candidates. In this study we examined the role of glucose and Na+ filtration rate on gene expression of glucose transporters in renal proximal tubule. SGLT1, SGLT2, GLUT1 and GLUT2 mRNAs were assessed by Northern blotting; and GLUT1 and GLUT2 proteins were assessed by Western blotting. Renal cortex and medulla samples from control rats (C), diabetic rats (D) with glycosuria, and insulin-resistant 15-month old rats (I) without glycosuria; and from normal (NS), low (LS), and high (HS) Na+-diet fed rats were studied. Compared to C and I rats, D rats increased (P < 0.05) gene expression of SGLT2 by approximately 36%, SGLT1 by approximately 20%, and GLUT2 by approximately 100%, and reduced (P < 0.05) gene expression of GLUT1 by more than 50%. Compared to NS rats, HS rats increased (P < 0.05) SGLT2, GLUT2, and GLUT1 expression by approximately 100%, with no change in SGLT1 mRNA expression, and LS rats increased (P < 0.05) GLUT1 gene expression by approximately 150%, with no changes in other transporters. In summary, the results showed that changes in glucose or Na+ filtrated rate modulate the glucose transporters gene expression in epithelial cells of the renal proximal tubule.

Animals↗
PubMed2001

Role of Rho-associated kinase in neointima formation after vascular injury.

BACKGROUND: The Rho/Rho-associated kinase (Rho-kinase) system is implicated in various cellular functions, including migration, proliferation, and apoptosis. Because a possible role of the system is suggested in neointima formation after vascular injury, we sought to examine whether a new specific Rho-kinase inhibitor, Y27632, prevents neointima formation of the balloon-injured rat carotid artery, and if so, to investigate the effects of Y27632 on migration, proliferation, and apoptosis of smooth muscle cells (SMCs) in the injured artery. METHODS AND RESULTS: Y27632 was administered intraperitoneally from 1 day before to 14 days after vascular injury. Treatment with Y27632 inhibited phenylephrine-induced Rho-kinase activation in the carotid artery on the basis of immunoblotting against the phosphorylated myosin-binding subunit of myosin phosphatase. Y27632 markedly prevented neointima formation at days 7 and 14. In controls, BrdU(+) proliferating and TUNEL(+) apoptotic SMCs were transiently and coincidentally increased in the neointima, with a peak at day 7. Y27632 significantly increased the neointimal TUNEL(+) SMCs at days 7 and 14, but not BrdU(+) SMCs. Y27642 significantly decreased the number of intimal SMCs at day 4, while not affecting the number of BrdU(+) or TUNEL(+) SMCs. Reendothelialization after balloon injury was not significantly affected by Y27632 at days 7 and 14. CONCLUSIONS: Y27632 inhibited neointima formation by enhancing SMC apoptosis and probably by suppressing early SMC migration. Therefore, a role of Rho-kinase is suggested in neointima formation after vascular injury.

Amides↗
PubMed2001

Diagnostic significance of tau protein in cerebrospinal fluid from patients with corticobasal degeneration or progressive supranuclear palsy.

Distinguishing corticobasal degeneration (CBD) from progressive supranuclear palsy (PSP) is clinically and pathologically difficult, and a useful biological marker to discriminative these two diseases has been a subject of clinical interest. In the present study, we assessed tau protein levels in cerebrospinal fluids by sandwich ELISA to distinguish CBD from PSP. The subjects consisted of 27 cases of CBD, 30 cases of PSP, and 36 healthy controls (CTL). The tau values in CBD were significantly higher than those in PSP (P<0.001) and those in CTL (P<0.001). The assay of CSF tau provided diagnostic sensitivity of 81.5% and specificity of 80.0% between CBD and PSP according to receiver-operating characteristic (ROC) curve analysis. When values were compared separately with respect to stage of the disease, differences in the values for moderate CBD vs. moderate PSP had the greatest significance (P<0.001 sensitivity 92.3%, specificity 100.0%), followed by cases of mild CBD and PSP (P<0.005, sensitivity 100.0%, specificity 87.5%). The values in severe CBD and PSP were not significantly different (P=0.07, sensitivity 100%, specificity 75.0%). Using data obtained from a larger number of disease cases, we confirmed our previous findings that tau protein levels in cerebrospinal fluids in patients with CBD are significantly higher than those in patients with PSP. Because tau protein levels in cerebrospinal fluids are significantly higher in early CBD cases than in early PSP cases, measurement of tau protein levels in cerberospinal fluids may be useful for the differential diagnosis of early CBD from early PSP.

Aged↗
PubMed2001

Isolation, characterization, and cDNA cloning of chicken turpentine-induced protein, a new member of the scavenger receptor cysteine-rich (SRCR) family of proteins.

Acute-phase serum proteins were induced by administrating a chicken with turpentine oil. One of these proteins was a new protein that appeared in front of albumin in polyacrylamide disc gel electrophoresis using a 4.5-16% gel. To purify this protein, turpentine-administrated chicken serum was fractionated by ammonium sulfate precipitation at 50% saturation, and the supernatant fraction was chromatographed on a DEAE-Toyopearl 650S column. The purified protein is a mannose-glycoprotein, and its N-terminal sequence, determined by the Edoman method, is not homologous from that of other reported acute-phase proteins. An analysis of physiological function with two different test systems, chemiluminescence measurement and electron spin resonance spectroscopy, showed that the purified protein has antioxidant activity and inhibits superoxide (O(2)) mediated by activation of the receptor. In support of these results, the complete amino acid sequence of 18-B is homologous to the scavenger receptor cysteine-rich (SRCR) family of proteins that participate in the regulation of leukocyte function. 18-B is composed of four SRCR domains, which is different from the previously characterized SRCR family of proteins such as Spalpha, CD6, and CD163. These findings indicate that turpentine-induced 18-B, a new member of scavenger receptor cysteine-rich family, may be implicated in regulation of cell function in a manner of inhibition of the overproduction of the reactive oxygen species.

Amino Acid Sequence↗
PubMed2001

Muscle weakness in Parkinson's disease: a follow-up study.

We compared isokinetic muscle strength between initial and subsequent measurements in 10 patients who could repeat the same testing later among 23 previously described patients with Parkinson's disease. Patients were divided into two groups according to changes in clinical condition between the times of the first and the subsequent measurements. For patients who had improved, both extension and flexion on the more affected side showed significantly greater torque at 15 rpm in the later than the earlier measurement. For patients who had worsened, both extension and flexion on the more affected side showed significantly less torque at 5 and 15 rpm in the later than the earlier measurement. Although isokinetic muscle strength is likely to depend on movement velocity in the early stages of Parkinson's disease, it may be influenced by bradykinesia, as the disease progresses. Speed-force correlation seen in these patients may give clues to the understanding of the pathophysiology of bradykinesia.

Aged↗
PubMed2001

Acute focal demyelinating disease simulating brain tumors: histopathologic guidelines for an accurate diagnosis.

The object of the present study was to determine the histopathological guidelines for accurate diagnosis of cases of acute focal demyelinating disease that simulates brain tumors. The surgical pathology of three such cases is assessed. Histopathological keys to the diagnosis of such cases are as follows. First, a pattern of sheets of atypical gemistocytic astrocytes in the white matter that show well-formed processes and that are adequately distanced from each other argues against a diagnosis of neoplasm. Second, uniform distribution of foamy macrophages aligned along axons, with occasional focal collections surrounding blood vessels and in the absence of any associated coagulative necrosis argues against the presence of a tumor. Third, perivascular chronic inflammatory infiltration, especially a mixture of lymphocytes and macrophages, favors the diagnosis of demyelination plaque. In such cases the lymphocytes will be predominantly T cells. Fourth, pleomorphic astrocytic proliferation with a lack of vascular endothelial proliferation should raise the suspicion that the lesion may not be a brain tumor. These diagnostic keys should be followed when diagnosing cases that are suspected to be demyelination processes rather than brain tumors. The presence of demyelination plaque should then be confirmed by imaging modalities such as staining with myelin-and axon-specific stains.

Adult↗
PubMed2001

Cloning and sequencing full length of canine Brca2 and Rad51 cDNA.

Mammary tumors are the most common neoplasm in female dogs, Canis canis, and in women. Mutations in human Brca2 confer an increased risk of female breast cancer. Previous studies have shown that the Brca2 tumor suppressor protein interacts with the recombinational repair protein Rad51. We cloned the full-length cDNA of the canine homologues of Brca2 and Rad51 to obtain a basis for studying their relationship with susceptibility to mammary tumors. The canine Brca2 and Rad51 cDNAs are 11 and 1.5 kb long, encoding 3.471 and 339 amino acids, respectively. The amino acid sequence of canine Brca2 showed 68% homology with the human protein, and 58% homology with a murine protein. There were highly conserved regions in the C-terminus of all three proteins, where the Rad51 interacting domain and putative nuclear localization signals are located. Comparing with the partial genomic sequence previously reported, we found possible nuclear polymorphisms in exon 11, some of which result in amino acid substitutions. On the other hand, canine Rad51 protein had extremely high homology (99%) to the human and murine proteins. Expression of both Brca2 and Rad51 was detected in the mammary gland, suggesting that these two genes interact in the canine mammary gland.

Amino Acid Sequence↗
PubMed2001

Malignant fibrous histiocytoma of the heart: case report and review of 46 cases in the literature.

A rare case of cardiac malignant fibrous histiocytoma (MFH) is reported. A 55-year-old woman complained of palpitation due to atrial fibrillation. Echocardiography, magnetic resonance imaging, and angiography demonstrated a tumor arising from the posterior wall of the left atrium. At surgery, the tumor was almost entirely resected and histologically defined as MFH. Neither chemotherapy nor irradiation was administered. Echocardiography revealed a local recurrence two months after the surgery and the patient died of advanced cachexy and heart failure 2 years later. The details of this case are presented with a review of the literature.

Age Factors↗
PubMed2001

Diltiazem, a calcium antagonist, inhibits matrix metalloproteinase-1 (tissue collagenase) production and collagenolytic activity in human vascular smooth muscle cells.

Calcium antagonists (CAs) are widely prescribed for patients with cardiovascular diseases. CAs have been reported to inhibit smooth muscle cell (SMC) proliferation in addition to their effects on vascular tone. To determine whether CAs potentially affect vascular remodeling, we measured the expression of matrix-degrading enzymes in growth factor-stimulated SMC. Human cultured SMC were stimulated with 10 ng/ml of platelet-derived growth factor (PDGF)-BB with or without a calcium antagonist, diltiazem. In the cell counting assay, diltiazem (10-5 M) alone had no effect on the proliferation of quiescent SMC, however 10-6-10-5 M of diltiazem dose-dependently inhibited PDGF-stimulated SMC proliferation. The inhibitory effects of diltiazem on SMC proliferation were further confirmed by a 5-bromo-2'-deoxyuridine (BrdU) incorporation assay and flow cytometry. In Western blotting, matrix metalloproteinase (MMP)-1 (tissue collagenase) but not MMP-2 (72-kDa gelatinase) expression was upregulated by PDGF and phorbol ester (TPA), which were reduced by diltiazem in a dose-dependent manner. The downregulation of MMP-1 expression was consistent with the reduction of collagenolytic activity measured by a FITC-conjugated type I collagen breakdown assay. PDGF-stimulated c-Jun/AP-1 expression, a major transcriptional factor for MMP-1, was not affected by diltiazem. In contrast, intracellular calcium ions measured with a fluorometric assay of Fluo-3AM-loaded cells revealed that the PDGF-stimulated increase in the intracellular calcium content was dose-dependently reduced by diltiazem. Our data suggest that diltiazem inhibits not only proliferation but also MMP-1 expression and collagenolytic activity in PDGF-stimulated SMC. The administration of CAs potentially influences the process of vascular remodeling, and this possibility should be further verified in vivo.

Blotting, Western↗
PubMed2001

Expression of G1 cell cycle markers and the effect of adenovirus-mediated overexpression of p21Waf-1 in squamous cell carcinoma of the esophagus.

To determine the crucial abnormality in the cell cycle regulatory proteins in human squamous cell carcinoma of the esophagus, we examined the cell growth ratio (CGR) and basal expression levels of G1 cyclins (cyclin D1, cyclin E), cyclin-dependent kinase (cdk) 2, cdk4, proliferating cell nuclear antigen (PCNA), and p21Waf-1 using 9 cell lines (KE3, KE4, TE8, TE9, TE10, TE11, YES1, YES2, and YES6). Western blotting revealed an inverse linear correlation between the basal levels of p21Waf-1 expression and CGR. The protein levels of G1 cyclins, cdks, and PCNA did not coordinately reflect the CGR. There was no relationship between p21Waf-1 expression levels and mutation of the p53 gene. Next, when the cells were stimulated with serum 48 h after the starvation, stimulated levels of the above G1 cell cycle markers were variously observed among cell lines irrespective of CGR. Serum stimulation markedly induced phosphorylated Rb in TE9 (a high CGR cell line, CGR>2.0), but not in KE4 (a low CGR cell line, CGR<1.5). Furthermore, adenovirus-mediated expression of exogenous p21Waf-1 effectively reduced cell growth in KE3 and TE9 (high CGR cell lines), but not in KE4 and TE11 (low CGR cell lines). p21Waf-1-mediated growth suppression was associated with the induction of involucrin, a marker of squamous cell differentiation. Our data suggested that the basal level, but not the stimulated level, of p21Waf-1 expression play a pivotal role in abnormal growth in human squamous cell carcinoma of the esophagus.

Adenoviridae↗
PubMed2001

The biochemical analysis of neurotransmitters in central neurocytomas.

Central neurocytomas are rare benign intraventricular tumours composed of small round synaptophysin-positive cells, suggesting a neuronal origin of these tumour cells. Although past electron microscopic studies demonstrated synaptic vesicles in the synapse of central neurocytomas, the kinds of neurotransmitters in central neurocytomas have never been identified. In this study we analyzed neurotransmitters in an attempt to clarify the tumorigenesis of central neurocytomas. We studied frozen central neurocytoma specimens from four patients. The tissue levels of glutamate and GABA (gamma-aminobutyric acid) in the tumours were determined by gas chromatography-mass spectrometry (GC-MS) using a selected ion monitoring method. The tissue levels of acetylcholine, choline, catecholamines and metabolites of catecholamines in the tumours were measured by high-performance liquid chromatography combined with electrochemical detection. Choline was found in extremely high concentration in all central neurocytomas when compared with levels in controls. In one central neurocytoma, GABA was found in extremely high concentration compared with controls. In all central neurocytomas, glutamate was found in lower or identical concentrations compared with controls. In all central neurocytomas and controls, dopamine and catecholamine concentrations were extremely low. These results indicated that the histogenesis of central neurocytomas begins with the subependymal stem cells, which have the potential to differentiate into cholinergic or GABA neurons.

Adult↗