PubMed Health⌕ Search

Biomedical subjects

N Kido

Publications and source records attributed to N Kido.

At least 19 recordsLinked to original sources
PubMed2001

Upregulated expression of N-syndecan, a transmembrane heparan sulfate proteoglycan, in differentiated neural stem cells.

Adult rat hippocampus-derived neural stem cells are incorporated into neural tissues, and differentiate to neuronal and glial cells. However, the cell surface protein molecules are, to date, undefined. RT-PCR, immunoblotting and immunocytochemistry showed the increased expression of N-syndecan, a transmembrane heparan sulfate proteoglycan, in the neural stem cells after the differentiation induced by retinoic acid. Our data indicate that N-syndecan may be involved in the differentiation of neural stem cells.

Animals↗
PubMed2001

Dual effects of interleukin-1beta on N-methyl-D-aspartate-induced retinal neuronal death in rat eyes.

In this study we determine if interleukin-1beta (IL-1beta) modulates N-methyl-D-aspartate (NMDA)-induced retinal damage. Sprague-Dawley rats were anesthetized with inhalation of halothane, after which a single injection of 5 microl of IL-1beta (0.1 to 10 ng/eye) (and/or IL-1 receptor antagonist (IL-1ra)) for experimental eyes was administered. Two days later (or simultaneously), NMDA (20 nmol) was injected into the vitreous space. One week later, each eye was enucleated and transverse sections were subjected to morphometric analysis. Enzyme-linked immunosorbent assay (ELISA) was conducted for the determination of IL-1beta levels in retina. Immunohistochemical and immunoblot studies were also performed. In eyes that received an intravitreal injection of IL-1beta (0.1 to 10 ng/eye), significant thinning of the inner plexiform layer (IPL) was observed (P<0.05). Immunohistochemical and ELISA studies demonstrated upregulated expression of IL-1beta in retinas that had undergone NMDA injection. Treatment with 10 ng of IL-1ra induced a protective effect against NMDA-induced retinal damage. Pretreatment with IL-1beta induced a significant protective effect on NMDA-induced retinal damage. Our studies suggest that IL-1beta induces neuronal cell death directly, as shown by the protective effects of IL-1ra, but has a protective effect on NMDA-induced retinal damage indirectly after an incubation time of at least 2 days.

Animals↗
PubMed2001

Effects of protein kinase inhibitor, HA1077, on intraocular pressure and outflow facility in rabbit eyes.

OBJECTIVE: To elucidate the roles of protein kinase in regulating the intraocular pressure (IOP) and outflow facility in rabbit eyes. MATERIALS AND METHODS: A protein kinase inhibitor, 1-(5-isoquinolinesulfonyl)-homopiperazine (HA1077), was used. The IOP and the outflow facility were measured before and after topical, intracameral, or intravitreal administration of HA1077 in rabbits. Western blot analysis was performed to detect the 20-kd light chain of myosin in human trabecular meshwork (TM) cells and bovine ciliary muscle (CM) tissues. The cell morphologic condition and distribution of actin filaments and vinculin in TM cells were studied using cell biology techniques. Carbachol-induced contraction of isolated bovine CM strips following administration of HA1077 was examined in a perfusion chamber. RESULTS: In rabbit eyes, the administration of HA1077 resulted in a significant decrease in IOP in a dose-dependent manner. An increased outflow facility was also observed. Western blot analysis revealed the presence of 20-kd light chain of myosin in human TM cells and bovine CM tissues. In cultured human TM cells, exposure to HA1077 disrupted actin bundles and impaired focal adhesion formation. In addition HA1077 showed relaxation of bovine CM strips. CONCLUSIONS: Use of HA1077 caused a reduction in IOP and an increase in the outflow facility. The results of in vitro experiments suggest that the IOP-lowering effects of HA1077 may be related to the altered cellular behavior of TM cells and relaxation of CM contraction. The results of these studies suggested that protein kinase inhibitors have the potential to be developed into a treatment modality for glaucoma.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2001

Interleukin-1beta mediates ischemic injury in the rat retina.

Two types of experiment were performed to examine the role of interleukin-1beta in ischemia-induced damage in the rat retina. In the in vivo study, enzyme-linked immunosorbent assay was used to investigate the expression of immunoreactive interleukin-1beta in the rat retina following a hypertension-induced ischemia/reperfusion, while the effect of a recombinant human interleukin-1 receptor antagonist or an anti-interleukin-1beta neutralizing antibody on the ischemia-induced damage was examined histologically. A transient increase in the expression of immunoreactive interleukin-1beta was observed in the retina 3-12 hr after reperfusion, and morphometric evaluation at 7 days after the ischemia showed a decrease in cell numbers in the ganglion cell layer and a decreased thickness of the inner plexiform layer with no change in the other retinal layers. Intravitreal injection of interleukin-1 receptor antagonist (1 or 10 ng per eye) or anti-interleukin-1beta antibody (50 or 500 ng per eye) 5 min before the onset of the ischemia reduced the damage. In the in vitro study, interleukin-1 receptor antagonist (500 ng ml(-1)) significantly reduced glutamate-induced neurotoxicity in rat cultured retinal neurons. These results suggest that interleukin-1 plays an important role in mediating ischemic and excitotoxic damage in the retina, and that interleukin-1 inhibitors may be therapeutically useful against neuronal injury caused by optic nerve or retinal diseases such as glaucoma and central retinal artery or vein occlusion.

Analysis of Variance↗
PubMed2001

Transforming growth factor-beta 2 levels in aqueous humor of glaucomatous eyes.

PURPOSE: To determine whether clinical characteristics are correlated with increased levels of transforming growth factor-beta 2 (TGF-beta 2) in aqueous humor in glaucomatous eyes. METHODS: Aqueous humor samples were collected from 91 glaucomatous eyes. Included were samples from primary open-angle glaucoma (POAG) in 40 eyes, (pseudo)exfoliation syndrome (EXS) in 18 eyes, primary angle-closure glaucoma (PACG) in 26 eyes and uveitis-related secondary glaucoma (SG) in 7 eyes. TGF-beta 2 in aqueous humor was assessed with a specific-capture ELISA. RESULTS: The mean concentration (+/- standard error) of mature (biologically active) TGF-beta 2 in the aqueous humor of eyes with POAG was 293.6 +/- 33.6 pg/ml, significantly higher than that in eyes with PACG, EXS and SG: 147.5 +/- 28.1, 135.8 +/- 30.2 and 41.0 +/- 10.7 pg/ml, respectively (P = 0.0006, P = 0.0010 and P = 0.0003; analysis of variance). The mean concentration (+/- standard error) of total TGF-beta 2 in the aqueous humor of eyes with POAG was 1647.6 +/- 124.5 pg/ml, not significantly different from that in eyes with PACG, EXS and SG: 1482.9 +/- 148.2, 1442.7 +/- 187.8 and 1929.0 +/- 367.6 pg/ml, respectively. A multivariate analysis using logistic regression showed significant correlations between mature TGF-beta 2 concentration and history of cataract surgery (P = 0.0225) and the use of carbonic anhydrase inhibitors (P = 0.0143). CONCLUSIONS: Our results indicate that increased levels of TGF-beta 2 may play an important role in the pathogenesis of POAG.

Aged↗
PubMed2001

Effects of rho-associated protein kinase inhibitor Y-27632 on intraocular pressure and outflow facility.

PURPOSE: To elucidate the roles of Rho-associated protein kinase (ROCK) in regulating intraocular pressure (IOP) and outflow facility in the rabbit eye. METHODS: A specific ROCK inhibitor Y-27632 was used. The IOP, the outflow facility, and the pupil diameter were determined before and after the topical, intracameral, or intravitreal administration of Y-27632 in rabbits. Western blot analysis was used to identify specific ROCK isoform in human trabecular meshwork (TM) cells and bovine ciliary muscle (CM) tissues. The cell morphology and distribution of actin filaments and vinculin in TM cells were studied by cell biology techniques. Carbachol (Cch)-induced contraction of isolated bovine CM strips after administration of Y-27632 was measured in a perfusion chamber. RESULTS: In rabbit eyes, administration of Y-27632 resulted in a significant decrease in IOP in a dose-dependent manner. An increase of the outflow facility and pupil size dilation was also observed in Y-27632-treated eyes. Western blot analysis revealed the presence of p160ROCK in human TM cells and bovine CM tissues. In cultured human TM cells, exposure to Y-27632 caused retraction and rounding of cell bodies as well as disruption of actin bundles and impairment of focal adhesion formation. Y-27632 in addition inhibited Cch-induced contraction of isolated bovine CM strips. CONCLUSIONS: Administration of Y-27632 caused a reduction in IOP and an increase in the outflow facility. The in vitro experiments suggest that the IOP-lowering effects of Y-27632 may be related to the altered cellular behavior of TM cells and relaxation of CM contraction. These studies suggest that ROCK inhibitors may have great potential to be developed for treatment of glaucoma and other ocular diseases.

Actins↗
PubMed2001

Inhibitory effects of neurocan and phosphacan on neurite outgrowth from retinal ganglion cells in culture.

PURPOSE: Neurocan and phosphacan are nervous tissue-specific chondroitin sulfate proteoglycans (CSPGs) that are highly expressed in postnatal rat retina. To elucidate potential roles of neurocan and phosphacan on neurite outgrowth from retinal ganglion cells (RGCs), in vitro experiments were conducted with purified RGCs. METHODS: Neurocan and phosphacan were purified from postnatal rat brain by DEAE-column chromatography and subsequent gel chromatography. RGCs were obtained from postnatal rat retinas by a two-step immunopanning procedure using an anti-Thy 1,1 antibody and an anti-macrophage antibody. Neurite outgrowth from RGCs was examined on poly-L-lysine (PLL)-conditioned plates, and PLL-conditioned plates treated with neurocan or phosphacan. RESULTS: Compared with PLL-conditioned plates, neurocan and phosphacan inhibited neurite outgrowth from RGCs at 48 and 72 hours after seeding. When chondroitin sulfate side chains linked to the core proteins were digested by chondroitinase ABC, the inhibitory effect remained, indicating that the core proteins are related to the effect. Furthermore, the digestion of chondroitin sulfate side chains linked to phosphacan core protein significantly promoted the inhibitory effect of phosphacan on neurite outgrowth from RGCs. CONCLUSIONS: Neurocan and phosphacan, which are highly expressed in postnatal rat retina, inhibit neurite outgrowth from postnatal rat RGCs, indicating that these proteoglycans may be inhibitory factors against neurite outgrowth from RGCs during retinal development.

Animals↗
PubMed2000

Neuroprotective effects of brain-derived neurotrophic factor in eyes with NMDA-induced neuronal death.

PURPOSE: To determine if brain-derived neurotrophic factor (BDNF) has a neuroprotective effect against N-methyl-D-aspartate (NMDA)-induced cell death in retina. METHODS: NMDA was injected into the vitreous of rat eyes. NMDA-induced neuronal death was measured by morphometric analyses on cell counts of ganglion cell layer cells and thickness of retinal layers. Also, we conducted additional experiment using retrograde labeling with a fluorescent tracer (Fluoro-Gold) for exact counting of retinal ganglion cells (RGCs). In addition, intravitreal glutamate levels were measured with the use of a high-performance liquid chromatography (HPLC) system. RESULTS: Morphometric analysis of retinal damage in NMDA-injected eyes showed that BDNF could protect inner retinal cells from glutamate receptor-mediated neuronal death. Also, counts of RGCs labeled with a fluorescent tracer showed that BDNF could protect RGCs from glutamate receptor-mediated neuronal death. Furthermore, measurements of intravitreal glutamate levels indicated an increase in this excitatory amino acid in the vitreous after NMDA injection. CONCLUSIONS: Exogenous BDNF can protect inner retinal cells (possible RGCs and amacrine cells) from NMDA-induced neuronal death. However, increased intravitreal glutamate levels in response to NMDA-mediated neurotoxicity may augment retinal degeneration.

Animals↗
PubMed2000

Secondary glaucoma associated with crystalline lens subluxation.

PURPOSE: To elucidate the clinical characteristics of secondary glaucoma associated with subluxation of the crystalline lens. SETTING: Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, and Department of Ophthalmology, Tenri Hospital, Nara, Japan. METHODS: This retrospective study comprised 14 eyes of 13 patients with uncontrolled intraocular pressure (IOP) and lens subluxation. The subluxated lens was extracted through surgery. RESULTS: Angle closure caused by the subluxated lens was complicated in 3 eyes. In the remaining 11 eyes, uncontrolled IOP elevation was found despite the presence of deep anterior chambers and wide open angles. A mean of 14.1 months +/- 13.7 (SD) after cataract surgery, IOP was well controlled (lower than 21 mm Hg) in all 14 eyes. Mean IOP was 15.4 +/- 2.2 mm Hg at the final examination. Complications included transient vitreous hemorrhage in 5 eyes, choroidal detachment in 2 eyes, and retinal tears in 1 eye. CONCLUSION: Lens extraction surgery was effective in controlling IOP in eyes with secondary glaucoma associated with lens subluxation.

Aged↗
PubMed2000

Molecular structure of bacterial endotoxin (Escherichia coli Re lipopolysaccharide): implications for formation of a novel heterogeneous lattice structure.

Analyses of crystals of Escherichia coli Re lipopolysaccharide (LPS) formed after storage in 1% triethylamine indicate that the LPS molecules are assembled to form a monolayered structure consisting of a novel heterogeneous lattice structure, the greater part of which is occupied by one kind of lattice (lattice I), corresponding to the acyl chain portion of lipid A, and the remainder is occupied by the other kind of lattice (lattice II), corresponding to the 3-deoxy-Dmanno-octulosonic acid (dOclA) dimer and the N-acetylglucosamine disaccharide of lipid A. X-ray diffraction reveals that the type of cell is monoclinic (a = 5.53 A, b = 27.2 A, c = 6.47 A, alpha = 90 degrees, beta = 125.8 degrees, gamma = 90 degrees ). Atomic force microscopy shows that crystals consist of multiple layers; the thickness of a layer corresponds to the b-axis value, and two types of surface topographies are visualized. One, regarded as the view onto the acyl chain ends, is two-dimensional arrays of oval bodies that constitute the lattice, with the lattice constants corresponding to the a- and c-axes and the angle of beta (lattice I). The other, regarded as the view onto the dOclA dimers, is two-dimensional arrays of dromedary-back-like bodies that constitute the lattice with axes of 9.0 and 10.7 A and the angle of 65 degrees formed by both axes (lattice II). Based on these results, we present the molecular model of E. coli Re LPS.

Carbohydrate Conformation↗
PubMed2000

A single amino acid substitution in a mannosyltransferase, WbdA, converts the Escherichia coli O9 polysaccharide into O9a: generation of a new O-serotype group.

wbdA is a mannosyltransferase gene that is involved in synthesis of the Escherichia coli O9a polysaccharide, a mannose homopolymer with a repeating unit of 2-alphaMan-1,2-alphaMan-1,3-alphaMan-1, 3-alphaMan-1. The equivalent structural O polysaccharide in the E. coli O9 and Klebsiella O3 strains is 2-alphaMan-1,2-alphaMan-1, 2-alphaMan-1,3-alphaMan-1,3-alphaMan-1, with an excess of one mannose in the 1,2 linkage. We have cloned wbdA genes from these O9 and O3 strains and shown by genetic and functional studies that wbdA is the only gene determining the O-polysaccharide structure of O9 or O9a. Based on functional analysis of chimeric genes and site-directed mutagenesis, we showed that a single amino acid substitution, C55R, in WbdA of E. coli O9 converts the O9 polysaccharide into O9a. DNA sequencing revealed the substitution to be conserved in other E. coli O9a strains. The reverse substitution, R55C, in WbdA of E. coli O9a resulted in lipopolysaccharide synthesis showing no ladder profile instead of the conversion of O9a to O9. This suggests that more than one amino acid substitution in WbdA is required for conversion from O9a to O9.

Amino Acid Sequence↗
PubMed2000

Expression of ciliary neurotrophic factor activated by retinal Müller cells in eyes with NMDA- and kainic acid-induced neuronal death.

PURPOSE: To elucidate the role of retinal Muller cells in N-methyl-D-aspartate (NMDA)- or kainic acid (KA)induced retinal damage. METHODS: In experimental eyes, NMDA or KA was injected into the vitreous of rat eyes. Immunohistochemistry and western blot analysis were conducted to elucidate expression and localization of glial fibrillary acidic protein (GFAP) and ciliary neurotrophic factor (CNTF). In addition, the neuroprotective effects of CNTF were calculated by counting cells in the ganglion cell layer (GCL) and by measuring the thickness of the various retinal layers. RESULTS: Morphometric analysis of retinal damage in NMDA- and KA-injected eyes showed significant cell loss in the GCL and thinning of the inner plexiform layer (IPL) of the retina, but not of other retinal layers. Immunohistochemistry demonstrated disappearance and/or decrease in immunoreactivities of calbindin- and calretinin- positive cells and their neurites and upregulated expression of both GFAP and CNTF in experimental eyes. Western blot analysis showed an increase in protein expression for CNTF in retinas of experimental eyes. Confocal images and sequential localization demonstrated colocalization of CNTF and GFAP in the inner retinal layer and possibly in Muller cells. In addition, pretreatment with CNTF (1 microg) before the intravitreal injection of NMDA (or KA) demonstrated that CNTF has neuroprotective effects against NMDA- or KA-induced neuronal death in the retina. CONCLUSIONS: These studies revealed the upregulated expression of CNTF and GFAP in Muller cells in response to NMDA- and KA-induced neuronal death, suggesting that production of CNTF in Muller cells may be a part of the endogenous neuroprotective system in the retina.

Animals↗
PubMed2000

Spatiotemporal expression patterns of 6B4 proteoglycan/phosphacan in the developing rat retina.

PURPOSE: To investigate expression of 6B4 proteoglycan/phosphacan, the major constituent of chondroitin sulfate proteoglycan and a possible modulator of neural network formation in the developing central nervous system, in developing rat retina. METHODS: Changes in expression and localization of 6B4 proteoglycan in developing rat retina were investigated by reverse transcription-initiated polymerase chain reaction (RT-PCR), immunohistochemistry, and immunoblot analysis. RESULTS: Semiquantitative RT-PCR revealed that mRNA expression of 6B4 proteoglycan in retinas peaked at postnatal day 14 (P14) and then decreased at P42. Immunohistochemical analyses using MAb 6B4, a monoclonal antibody against 6B4 proteoglycan, revealed faint immunoreactivity in the inner aspects of the retina at embryonal day 16 (E16). At birth, weak immunoreactivity was present in the nerve fiber layer (NFL) and inner plexiform layer (IPL). At P7 and P14, the NFL, IPL, and outer plexiform layer (OPL) stained intensely, but the ganglion cell layer (GCL) remained unstained. Between P21 and P42, immunoreactivity in the NFL and IPL weakened slightly. Immunoblot analyses showed a MAb 6B4 immunopositive band in the retinal soluble fraction treated with chondroitinase ABC. The amount of the immunopositive band increased rapidly as retinal development proceeded. Surprisingly, a significant amount of the immunopositive band was present in the retina even before digestion with chondroitinase ABC, indicating that at least part of 6B4 proteoglycan in rat retina exists in a non-proteoglycan form. CONCLUSIONS: The existence of 6B4 proteoglycan/phosphacan was thus demonstrated in rat retina, although some biochemical parameters were different from those of the 6B4 proteoglycan seen in brain.

Animals↗
PubMed2000

Upregulated expression of neurocan, a nervous tissue specific proteoglycan, in transient retinal ischemia.

PURPOSE: Neurocan, a nervous tissue-specific chondroitin sulfate proteoglycan synthesized primarily by neurons, is expressed abundantly in developing rat retina, whereas it is rarely expressed in adult rat retinas. This study investigated the reexpression of neurocan in a pathologic condition of adult rat retina. METHODS: Transient retinal ischemia was produced by occlusion of the retinal artery for 60 minutes. After transient retinal ischemia, neurocan expression was investigated by reverse transcription-initiated polymerase chain reaction (RT-PCR), immunohistochemistry, and immunoblot analysis. RESULTS: Semiquantitative analysis using RT-PCR revealed that mRNA expression for neurocan increased at 24 hours after reperfusion. Furthermore, on immunoblot analysis using an anti-neurocan antibody, MAb 1G2, the intensity of the 220-kDa band as well as the 150-kDa band increased markedly at 24 and 72 hours after reperfusion. The 220-kDa band was predominant at 24 hours after reperfusion, whereas the intensity of the 150-kDa band became almost the same as that of the 220-kDa band at 72 hours after reperfusion. Immunohistochemical analysis revealed that upregulated neurocan immunoreactivity was associated with glial Müller cells. CONCLUSIONS: Thus, upregulated expression of neurocan in transient retinal ischemia was demonstrated. Furthermore, the immunohistochemical analysis revealed that the upregulated expression of neurocan is derived from Müller cells, although it has been thought that neurocan is synthesized by neurons so far. The neurocan expression by Müller cells suggests that this proteoglycan plays a role in the damage and repair processes in diseased retina.

Animals↗
PubMed2000

Neuroglycan C, a neural tissue-specific transmembrane chondroitin sulfate proteoglycan, in retinal neural network formation.

PURPOSE: Neuroglycan C (NGC) is a transmembrane chondroitin sulfate proteoglycan present exclusively in central nervous system tissues. In the current study the expression pattern and characterization of NGC during the development of the retina were investigated. METHODS: Expressional changes of NGC mRNAs during rat retinal development were examined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). The localization and characterization of NGC core proteins were investigated by immunoblot analysis and immunohistochemistry using an anti-NGC antibody. RESULTS: Immunohistochemical analysis revealed that NGC was highly expressed in the nerve fiber layer (NFL) and inner plexiform layer (IPL) in rat postnatal developing retina. At embryonal stages, NGC immunoreactivities were faint. In contrast, at postnatal developmental stages (approximately postnatal day [P]7), intense immunoreactivity was observed in the NFL and IPL, where active dendrite branching was observed, and conventional synapses began to be formed. As retinal layer differentiation proceeded (from P14 to P42), immunoreactivities in the inner retinal layers gradually became fainter. Immunoblot and semiquantitative RT-PCR analyses showed that the peak level of NGC expression occurred on approximately P7 and P14. Glycosylation of the NGC core protein changed as the retinal layers matured. In immunoelectron microscopic analysis, NGC immunoreactivity was located on the axonal membranes of neuronal cells in the postnatal retina, whereas immunoreactivity was reduced on membranes at the adult stage. In retinal ganglion cells in vitro, NGC was highly localized in their spiny budding neurites. CONCLUSIONS: The results show spatiotemporal expression patterns of NGC, and suggest that it plays a role in the formation of neural networks in retinal development.

Animals↗
PubMed1999

Identification of the hemidesmosomal 500 kDa protein (HD1) as plectin.

HD1 is a 500 kDa hemidesmosomal plaque protein recognized by monoclonal antibody mAb-121. Recent research on inherited skin disease has suggested that it might be identical to plectin or an isoform. To cast light on this question, we have prepared several monoclonal antibodies that recognize a 500 kDa protein in the hemidesmosome fraction. Unexpectedly, some staining pattern heterogeneity was observed on immunofluorescence microscopy. Attention was focused on two monoclonal antibodies which gave different localization in bovine skin and retinal pigment epithelial cells. Determination of the amino-terminal sequence of an antigenic 100 kDa polypeptide fragment derived from the 500 kDa component of an insoluble fraction of bovine hepatocytes revealed it was identical to that of plectin. Using the two antibodies, we screened a cDNA library derived from BMGE+H, a bovine mammary gland epithelial cell line. The isolated cDNA clones corresponded to the rod domain of bovine plectin, with two separate epitope regions for each of the antibodies. From these results we conclude that the hemidesmosomal 500 kDa component HD1 is identical to plectin. As judged on rough estimation of molar ratios on this basis, hemidesmosomes are composed of plectin, BP230, the integrin beta4 subunit, and alpha6 in a 1:1:1:1 ratio.

Animals↗
PubMed1999

A novel gene required for rhamnose-glucose polysaccharide synthesis in Streptococcus mutans.

Gene rgpG is required for biosynthesis of rhamnose-glucose polysaccharide (RGP) in Streptococcus mutans. Its deduced amino acid sequence had similarity to WecA, which initiates syntheses of enterobacterial common antigen and some O antigens in Escherichia coli. Gene rgpG complemented a wecA mutation of E. coli, suggesting that rgpG may function similarly in RGP synthesis.

Cloning, Molecular↗