Biomedical subjects

N Morisaki

Publications and source records attributed to N Morisaki.

At least 55 records · Page 3Linked to original sources

PubMed1998

Synthesis and anti-tubulin activity of ustiloxin D derivatives.

Ustiloxin D, produced by the rice plant pathogen Ustilaginoidea virens, exhibits potent anti-tubulin activity. In order to elucidate the effects of functional groups in ustiloxin D on its activity, several derivatives were synthesized and their anti-tubulin activities were estimated. The N,N-dimethylamino derivative and the 14-O-methyl derivative were inactive (IC50 > 50 microM). 20-Hydroxymethylated ustiloxin D showed decreased inhibitory activity compared with ustiloxin D.

Animals↗

PubMed1998

[Change of cytokines and clinical efficacy of panipenem/betamipron in obstetric and gynecological infections. Yamagata Study Group of Panipenem/Betamipron in Obstetric and Gynecological Infections].

Efficacy and safety of panipenem/betamipron (PAPM/BP) in treatment of obstetric and gynecological infections, and change of interleukin-6 (IL-6) and interleukin-8 (IL-8) levels in blood, as markers of infection, were investigated. The results were as follows; 1) Clinical efficacy of PAPM/BP by drip infusion of 1-2 g/day for 3-14 days against 52 patients with intrauterine infection (n = 29), pelveoperitonitis (n = 19), and other infections were 14 "Excellent" in 14 cases, "Good" in 35 cases, and efficacy rate was 94.2% (49/52). Both efficacy rate analy by causative organisms and eradication rate were 35/37 (94.6%). No subjective or objective side effects and no abnormal labolatory findings were observed. 2) Changes of IL-6 (> 4 pg/ml) levels in serum, as an infection marker, were observed in 8 cases out of 14 cases (57.1%), and correlation between CRP and IL-6 in the treatment process was noticed. However, changes of serum IL-8 (> 12.5 pg/ml) were observed in only 2 cases of those 14 cases (14.3%), indicative that IL-8 has no significance as a marker of infection.

Adolescent↗

PubMed1998

Stimulation of cholesterol release from rabbit foam cells by the action of a new inhibitor for acyl CoA:cholesterol acyltransferase (ACAT), HL-004.

A new inhibitor of acyl CoA:cholesterol acyltransferase (ACAT), HL-004 [N-(2, 6-diisopropylphenyl)tetradecylthioacetamide], suppressed the synthesis of cholesterol [14C]oleate at 10(-9) approximately 10(-7) M in a concentration-dependent manner in both THP-1 cell-derived macrophages and foam cells prepared from aortic intima of rabbits fed a high cholesterol diet. Incorporation of [3H]cholesterol oleate-beta very low density lipoproteins was not inhibited by HL-004 at 10(-9) approximately 10(-7) M. Release of radioactivity from the cells loaded with [3H]cholesterol oleate-beta very low density lipoproteins was increased by the inhibition of ACAT activity with HL-004. HL-004 did not affect on acid and neutral cholesterol esterases. As a result, cholesterol ester content in foam cells decreased. These data suggested that HL-004 decreases cholesterol ester in foam cells by increasing the release of cholesterol and therefore might suppress atherosclerotic lesions.

Acetanilides↗

PubMed1997

Local expression of C-type natriuretic peptide markedly suppresses neointimal formation in rat injured arteries through an autocrine/paracrine loop.

BACKGROUND: In vivo gene transfer into injured arteries may provide a new means to facilitate molecular understanding of and to treat the intractable fibroproliferative arterial diseases. Selection of an optimal molecule to be transferred will be a key to successful gene therapy in the future. We tested the hypothesis that a secreted multifactorial molecule should act more efficiently through an autocrine/paracrine loop to suppress neointimal formation elicited in injured arteries than a simple growth-inhibiting molecule that might be expressed inside cells. METHODS AND RESULTS: We constructed an adenoviral vector (AdCACNP) expressing C-type natriuretic peptide (CNP), a secreted stimulator of membrane-bound guanyl cyclase. AdCACNP directs cells to secrete large quantities of biologically active CNP. Serum-stimulated DNA synthesis and cell proliferation were only moderately suppressed in arterial smooth muscle cells infected with AdCACNP in vitro. However, when AdCACNP was applied to balloon-injured rat carotid arteries in vivo, neointimal formation was markedly reduced (90% reduction) in an infection-site-specific manner without an increase in plasma CNP level. CONCLUSIONS: Our results showed that CNP, a secreted multifactorial molecule, was indeed effective in suppressing fibroproliferative response in injured arteries and suggest that the potent antiproliferation effect may not be the most critical factor for the effective suppression of neointimal formation. An adenovirus-mediated expression of CNP could be an effective and site-specific form of molecular intervention in proliferative arterial diseases.

Adenoviridae↗

PubMed1997

Serotonin (5-hydroxytryptamine, 5-HT) enhances migration of rat aortic smooth muscle cells through 5-HT2 receptors.

The effects of serotonin on migration of cultured rat aortic smooth muscle cells (SMC) were studied to clarify the role of this substance in the pathogenesis of atherosclerosis. Serotonin alone did not stimulate SMC migration but stimulated it at physiological concentrations in the presence of other migration factors such as SMC-derived migration factor, platelet-derived migration factor and fibronectin. Checker-board analysis revealed that the serotonin effect was chemotactic. Moreover, serotonin effects were completely abolished by a selective inhibitor of the 5-HT2 receptor (MCI-9042), indicating that serotonin effects were mediated through the 5-HT2 receptor pathway. Finally, serotonin effects were also abolished by a phospholipase C inhibitor, U73122, suggesting that the 5-HT2 receptor mediated signal of serotonin was transduced by PLC. The results suggest that platelet-derived serotonin plays some role in the SMC dominant neointima formation.

Animals↗

PubMed1997

Transforming growth factor-beta receptor and fibronectin expressions in aortic smooth muscle cells in diabetic rats.

Smooth muscle cells in arteries of diabetic rats and rabbits have unique properties including the overexpression of platelet-derived growth factor (PDGF) beta-receptor compared with controls. Fibronectin, one of the increased components of extra-cellular matrices in diabetic arteries, plays an important role in the phenotypic change of smooth muscle cells from the contractile to the synthetic type with the expression of the PDGF beta-receptor. Moreover, fibronectin synthesis is regulated by transforming growth factor-beta (TGF-beta). In this study, we report on the expression of TGF-beta receptors in diabetic smooth muscle cells, by immunohistochemistry, cross-linking of 125I-TGF-beta 1 to cells and quantitative reverse transcription-polymerase chain reaction. We also report on the effects of TGF-beta 1 on fibronectin synthesis of diabetic smooth muscle cells by use of ELISA and immunoprecipitation, in order to clarify the role of TGF-beta-fibronectin pathway in forming characteristic changes of diabetic smooth muscle cells. Cultured aortic smooth muscle cells of diabetic rats expressed TGF-beta type II receptor about 8.7 times that of controls at the protein level and 5.7 times at the mRNA level, whereas the expression of the type I receptor did not differ between the two types of smooth muscle cells. These changes were accompanied by increased fibronectin synthesis in diabetic smooth muscle cells in response to TGF-beta 1. Furthermore, protein expression of fibronectin, and mRNA and protein of TGF-beta type II receptor were increased in the diabetic aorta compared with the control aorta in vivo, implying the importance of the TGF-beta-fibronectin pathway for the unique biology of smooth muscle cells in the diabetic artery.

Analysis of Variance↗

PubMed1997

Cultured retinal pericytes stimulate in vitro angiogenesis of endothelial cells through secretion of a fibroblast growth factor-like molecule.

Interaction between cultured endothelial cells (EC) and pericytes (PC) was studied in vitro to clarify the mechanism of diabetic proliferative retinopathy. Conditioned medium (CM) from retinal PC strongly increased the proliferation and moderately stimulated migration of retinal EC. Moreover, CM from PC caused stimulation of angiogenesis of retinal EC and umbilical cord vein EC in vitro at the same extent as basic fibroblast growth factor (bFGF). PC also stimulated angiogenesis by EC in mixed cultures. The angiogenic, proliferative and migration activities in CM from PC were inhibited by an antibody to bFGF. These data suggest that PC play an important role in angiogenesis through secretion of an FGF-like molecule.

Animals↗

PubMed1997

New indices of ischemic heart disease and aging: studies on the serum levels of soluble intercellular adhesion molecule-1 (ICAM-1) and soluble vascular cell adhesion molecule-1 (VCAM-1) in patients with hypercholesterolemia and ischemic heart disease.

It is known that the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the surface of vascular endothelial cells is closely related to the formation of early atherosclerotic lesions. In this study, serum soluble ICAM-1(sICAM-1) and soluble VCAM-1(sVCAM-1) were determined by sandwich ELISA both in normal healthy individuals (n = 114) and in patients with hypercholesterolemia (HC, n = 112) or ischemic heart disease (IHD, n = 38) to clarify the significance of the soluble forms of the adhesion molecules in the development of atherosclerotic diseases. IHD patients, not HC patients, showed significant elevation of sICAM-1, but not of sVCAM-1, compared with controls in age and sex-matched subjects. In addition, multiple linear regression analysis showed that sICAM-1 was correlated only to the presence of IHD but not to age and lipids. Multiple logistic regression analysis revealed that sICAM-1 was the most powerful independent predictor of the presence of IHD. On the other hand, sVCAM-1, not sICAM-1, was positively correlated to age. Multiple linear regression analysis showed that age was the most powerful independent predictor of the level of sVCAM-1. These data suggest that sICAM-1 and sVCAM-1 are useful as indices of clinical manifestations of atherosclerosis and aging, respectively.

Adult↗

PubMed1997

Type III hyperlipidaemia with primary hypothyroidism: a unique clinical course of hyperlipidaemia during replacement therapy of thyroid hormone.

A patient is described with type III hyperlipidaemia and primary hypothyroidism who had a unique clinical course of hyperlipidaemia. The patient was a 65-year-old man with primary hypothyroidism. His plasma total cholesterol, triglyceride and high density lipoprotein-cholesterol concentrations 1 year after starting thyroid hormone replacement therapy were 7.98, 4.04 and 0.72 mmol/l, respectively. His plasma apolipoprotein (apo) E level was 0.29 g/l and its phenotype was E2/2. Remarkably, this patient had no hyperlipidaemia before starting thyroid hormone replacement therapy but it became overt only after the hypothyroidism had been treated. Although we have not confirmed the mechanism for this, we speculate that a decrease in enzyme activities responsible for cholesterol production may have been sufficient to surpass the effect of apolipoprotein E2/2 and the decrease in enzyme activities involved in degrading and excreting plasma cholesterol, resulting in normolipidaemia.

Aged↗

PubMed1997

Increased blood plasminogen activator inhibitor-1 and intercellular adhesion molecule-1 as possible risk factors of atherosclerosis in Werner syndrome.

Werner syndrome is a rare premature aging syndrome accompanied by severe atherosclerosis. The etiology of atherosclerosis is suspected to be due to its complications, namely diabetes mellitus, hyperinsulinemia and hyperlipidemia. But from an autopsy case we found that some other risk factors may be involved in the mechanism of atherosclerosis in this syndrome. Previously we revealed that the plasminogen activator inhibitor-1 (PAI-1) gene was being overexpressed in skin fibroblasts from a patient with this syndrome. PAI-1 is a potent inhibitor of tissue plasminogen activator and a possible risk factor of atherosclerosis. This led us to assess the plasma concentration of PAI-1. Our working hypothesis was that the PAI-1 gene was upregulated or not fully suppressed in cells responsible for the production of PAI-1 in plasma as well as in fibroblasts. The results show a high concentration of plasma PAI-1. One of the well-known physiological substances that induce the PAI-1 gene is tumor necrosis factor-alpha, which also induces other possible risk factors of atherosclerosis, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1. We found the serum concentrations of ICAM-1 to be elevated in patients with this syndrome. We conclude that high concentrations of PAI-1 and ICAM-1 in blood may be one of the potent causes of severe atherosclerosis in Werner syndrome.

Adult↗

PubMed1997

Natriuretic peptide family as a novel antimigration factor of vascular smooth muscle cells.

Vascular smooth muscle cell (SMC) migration is proposed to be an important process in the initiation and/or progression of atherosclerosis. The present study examined the effects of the natriuretic peptide family (atrial, brain, and C-type natriuretic peptides; ANP, BNP, and CNP) on the migration of cultured rat SMCs, using Boyden's chamber methods. Fetal calf serum (FCS) and platelet-derived growth factor (PDGF)-BB potently stimulated SMC migration. Rat ANP(1-28), rat BNP-45, and rat CNP-22 clearly inhibited SMC migration stimulated with FCS or PDGF-BB in a concentration-dependent manner. CNP-22 had the most potent inhibitory effect compared with other natriuretic peptides. When PDGF-BB-induced migration was separated into chemotactic and chemokinetic activities, the chemotactic component was strongly inhibited by these natriuretic peptides. Such inhibition by these natriuretic peptides was paralleled by an increase in the cellular level of cyclic GMP. The addition of a cyclic GMP analogue, 8-bromo cyclic GMP, and an activator of the cytosolic guanylate cyclase, sodium nitroprusside, significantly inhibited FCS- and PDGF-BB-stimulated migration in a concentration-dependent manner. These results suggest that natriuretic peptides, especially CNP-22, inhibit FCS- or PDGF-BB-stimulated SMC migration at least in part through a cyclic GMP-dependent process. Thus, the natriuretic peptide family may play a role as an antimigration factor of SMCs under certain circumstances.

Animals↗

PubMed1997

A novel mosaic protein containing LDL receptor elements is highly conserved in humans and chickens.

Certain receptors belonging to the LDL receptor (LDLR) gene family appear to constitute a newly identified branch whose members are expressed in brain, in addition to other tissues. In support of this concept, we have now discovered the expression and delineated the molecular structures of a representative of this emerging branch from two such diverse species as human and chicken. This membrane receptor, called LR11 and thus far only known to exist in the rabbit, is a complex seven-domain mosaic protein containing, among other structural elements, a cluster of 11 LDLR ligand-binding repeats and a domain with homology to VPS10, a yeast receptor for vacuolar protein sorting. Cytoplasmic signature sequences define the receptor as competent for endocytosis. The most striking properties of LR11s are their (1) high degree of structural conservation (>80% identity among mammals and birds), with 100% identity in the membrane-spanning and cytoplasmic domains of rabbit and human; (2) lack of regulation by cholesterol and estrogen; and (3) expression in brain. The features of LR11 suggest important roles in intercellular and intracellular ligand transport processes, some of which it may share with other brain-specific LDLR family members.

Amino Acid Sequence↗

PubMed1997

Photoaffinity labeling of the ligand-interacting helix of the retinoic acid receptor alpha.

Two photoaffinity-labeling probes for retinoic acid receptor (RAR) alpha, 4-[(3-(3-(trifluoromethyl)-3H-diazirin-3-yl)phenyl)carboxamido]ben zoic acid (3DIAM) and its para-isomer (4DIAM), were designed and synthesized. Both compounds possess high affinity for recombinant RAR alpha (MBP-RAR alpha/E) and bind covalently to its cognate ligand-binding site. The labeled site of MBP-RAR alpha/E with 3DIAM was determined, by the endoproteinase combination method, to be located in helix 11 of the ligand-binding domain of RAR alpha, which is the position at which the ligand is considered to bind, on the basis of the reported crystal structure of the retinoic acid/RAR gamma complex.

Azirines↗

PubMed1997

Structural identification of a major cytokinin in coconut milk as 14-O-(3-O-[beta-D-galactopyranosyl-(1-->2)-alpha-D-galactopyranosyl- (1-->3)-alpha-L-arabinofuranosyl]-4-O-(alpha-L-arabinofuranosyl)- beta-d-galactopyranosyl)-trans-zeatin riboside.

A cytokinin isolated from the fluid endosperm of Cocos mucifera L. (coconut milk), accounting for more than 20% of the total cytokinin activity, was structurally analyzed by NMR techniques, mass spectrometry, and sugar analysis by high performance liquid chromatography (HPLC). The planar structure of the cytokinin was deduced from its NMR and mass spectrometric data. The structure of the sugar moiety, including its absolute structure, was determined by HPLC analysis of alditol acetates and aldononitrile acetates derived from the cytokinin. The configuration of the sugar-sugar bonds was determined by NMR, and the structure was finally identified as 14-O-(3-O-[-beta-D-galactopyranosyl-(1-->2)-alpha-galactopyranosyl-(1--> 3)- alpha-L-arabinofuranosyl]-4-O-(alpha-L-arabino-furanosyl)-beta-D- galactopyranosyl)-trans-zeatin riboside.

Carbohydrate Sequence↗

PubMed1997

The receptor for advanced glycation end products mediates the chemotaxis of rabbit smooth muscle cells.

Long-term incubation of proteins with glucose leads to advanced glycation end products (AGEs) with fluorescence and a brown color. We recently demonstrated immunologically the intracellular AGE accumulation in smooth muscle cell (SMC)-derived foam cells in advanced atherosclerotic lesions. To understand the mechanism of AGE accumulation in these foam cells, we have now characterized the interaction of AGE proteins with rabbit-cultured arterial SMCs. In experiments at 4 degrees C, 125I-labeled AGE-bovine serum albumin (AGE-BSA) showed a dose-dependent saturable binding to SMCs with an apparent dissociation constant (Kd) of 4.0 microg/ml. In experiments at 37 degrees C, AGE-BSA underwent receptor-mediated endocytosis and subsequent lysosomal degradation. The endocytic uptake of 125I-AGE-BSA was effectively inhibited by unlabeled AGE proteins such as AGE-BSA and AGE-hemoglobin, but not by acetylated LDL and oxidized LDL, well-known ligands for the macrophage scavenger receptor (MSR). Moreover, the binding of 125I-AGE-BSA to SMCs was affected neither by amphoterin, a ligand for one type of the AGE receptor, named RAGE, nor by 2-(2-furoyl)-4(5)-(2-furanyl)-1H-imidazole-hexanoic acid-BSA, a ligand for the other AGE receptors, p60 and p90. This indicates that the endocytic uptake of AGE proteins by SMCs is mediated by an AGE receptor distinct from MSR, RAGE, p60, and p90. To examine the functional role of this AGE receptor, the migratory effects of AGE-BSA on these SMCs were tested. Incubation with 1-50 microg/ml of AGE-BSA for 14 h resulted in significant dose-dependent cell migration. The AGE-BSA-induced SMC migration was chemotactic in nature and was significantly inhibited (approximately 80%) by an antibody against transforming growth factor-beta (TGF-beta), and the amount of TGF-beta secreted into the culture medium from SMC by AGE-BSA was sevenfold higher than that of control, indicating that TGF-beta is involved in the AGE-induced SMC chemotaxis. These data suggest that AGE may play a role in SMC migration in advanced atherosclerotic lesions.

Animals↗

PubMed1996

Elements of neural adhesion molecules and a yeast vacuolar protein sorting receptor are present in a novel mammalian low density lipoprotein receptor family member.

Normal cell development depends to a large part on multifunctional proteins that have evolved by recombination of proven modular elements. We now have discovered and characterized in rabbit such a multi-domain protein, and classify it as novel member of the low density lipoprotein (LDL) receptor gene family. The extracellular portion of the approximately 250-kDa membrane protein, termed LR11, contains a cluster of 11 LDL receptor ligand binding repeats, a group of 5 LDL receptor "YWTD" repeats, a large hexarepeat domain of structural elements found in neural cell adhesion molecules, and a domain with similarity to a yeast receptor for vacuolar protein sorting, VPS10. The cytoplasmic domain exhibits features typical of endocytosis-competent coated-pit receptors. The mosaic, and presumably multifunctional, receptor is expressed abundantly in brain, in particular the hippocampus, dentate gyrus, and cerebral cortex, and is present at significant levels in liver, adrenal glands, and testis. Western blotting of tissues and ligand blotting of LR11-transfected cells demonstrated that the novel protein binds apolipoprotein E-containing lipoproteins. In contrast to the LDL receptor, hepatic expression of LR11 is unaffected by hyperlipidemia. The identification of this highly conserved and superbly complex protein offers the opportunity to gain new insights into the emergence of multifunctional mosaic proteins akin to the ever expanding LDL receptor gene family.

Amino Acid Sequence↗

PubMed1996

Phosphatidylinositol 3-kinase activity is required for the activation process of focal adhesion kinase by platelet-derived growth factor.

Platelet-derived growth factor (PDGF) is one of the agents which stimulate increase in phosphotyrosine content of focal adhesion kinase (FAK) in cultured cells. In the present study we report that wortmannin, a highly specific and potent inhibitor of the catalytic subunit of mammalian phosphatidylinositol (PI) 3-kinase, completely abolishes PDGF-BB-mediated increase in tyrosine phosphorylation of FAK in human umbilical vein smooth muscle cells. Furthermore, analysis of the wild-type and mutant human PDGF beta-receptors stably expressed in porcine aortic endothelial cells also demonstrates that the Y740/751F mutant receptor, which cannot interact with PI 3-kinase due to the mutational alteration of its binding sites for PI 3-kinase, fails to increase FAK phosphorylation after PDGF-BB stimulation. These data suggest the requirement for PI 3-kinase activity in the activation process of FAK downstream of the PDGF receptor.

Androstadienes↗

PubMed1996

Granulocyte/macrophage colony-stimulating factor is an intrinsic keratinocyte-derived growth factor for human melanocytes in UVA-induced melanosis.

Recently we demonstrated that endothelins secreted from human keratinocytes act as intrinsic mitogens and melanogens for human melanocytes in UVB-induced melanosis. We show here that UVA-induced melanosis is associated with other keratinocyte-derived growth factors, secretion of which is specifically stimulated after exposure of human keratinocytes to UVA. Medium conditioned by UVA-exposed human keratinocytes elicited a significant increase in DNA synthesis by cultured human melanocytes in a UVA dose-dependent manner. Analysis of endothelin-1 and interleukin (IL)-1 alpha in the conditioned medium by ELISA, both of which are major keratinocyte-derived cytokines involved in UVB-associated melanocyte activation, revealed that UVA exposure did not cause human keratinocytes to stimulate the secretion of the two cytokines. In contrast, the levels of several other cytokines such as IL-6, IL-8 and granulocyte/macrophage colony-stimulating factor (GM-CSF) were significantly increased in the conditioned medium of human keratinocytes after exposure to UVA at a dose of 1.0 J/cm2. The gel chromatographic profile of UVA-exposed keratinocyte-conditioned medium demonstrated that there were two factors (P-1 and P-2) with molecular masses of approx. 20 and 1 kDa respectively that stimulate DNA synthesis in human melanocytes, and the larger species (P-1) also increased melanization as assessed by [14C]thiouracil incorporation. Quantitative analysis of cytokines in chromatographic fractions by ELISA revealed the P-1 fraction to be consistent with the molecular mass profile of GM-CSF. Furthermore the stimulatory effect of the P-1 fraction on DNA synthesis in human melanocytes was neutralized by antibodies to GM-CSF, but not to basic fibroblast growth factor or stem cell factor. Binding and proliferation assays with recombinant GM-CSF demonstrated that human melanocytes possess specific binding sites for GM-CSF(Kd 2.11 nM; binding sites, 2.5-3.5 x 10(4) per cell), and recombinant GM-CSF at concentrations of more than 10 nM significantly stimulated DNA synthesis and melanization. These findings suggest that GM-CSF secreted by keratinocytes plays an essential role in the maintenance of melanocyte proliferation and UVA-induced pigmentation in the epidermis.

Cells, Cultured↗