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D Fujimoto

Publications and source records attributed to D Fujimoto.

At least 37 records · Page 2Linked to original sources
PubMed1993

Active oxygen-induced modification alters properties of collagen as a substratum for fibroblasts.

Acid-soluble collagen from rat skin was modified by active oxygen in vitro, and properties of the modified collagen as a substratum for fibroblasts were studied. When collagen was treated with ascorbate-copper ion systems, cross-linking and a little degradation occurred rapidly. The cells attached but spread poorly on the modified collagen gel as compared with on the untreated collagen gel. On the other hand, when collagen was treated with H2O2-copper ion systems, only degradation of collagen molecule occurred rapidly. This treatment did not affect the attachment and spreading of the cells on the collagen gel, but when the incubation was continued for a long time, the cells migrated actively and gathered. Thymidine incorporation by the cells was suppressed on both modified collagen gels as compared with that on untreated collagen gel, and the extent of the suppression on the H2O2-copper-treated collagen was larger than that on the ascorbate-copper-treated collagen. These results indicate that the active oxygen-induced cross-linking and degradation significantly alter properties of collagen as a substratum for fibroblasts.

Animals↗
PubMed1993

Interaction of human plasma fibronectin with alpha-elastin.

Because there are contradictory reports about the interaction of plasma fibronectin with elastin, we investigated the interaction in vitro. When human plasma was applied to an alpha-elastin-Sepharose column at 4 degrees C, the column-binding fraction contained fibronectin. When isolated plasma fibronectin was applied to the same column at 4 degrees C, most of the fibronectin bound to the column and was eluted with 1 M KBr. However, the binding affinity of plasma fibronectin to the alpha-elastin-Sepharose column was much weaker at 25 degrees C than at 4 degrees C. The elastin-plasma fibronectin interaction was further confirmed by demonstrating the binding of alpha-elastin to fibronectin on polyvinylidene difluoride membranes using an alpha-elastin specific antibody. The elevation of the surface hydrophobicity of plasma fibronectin at 4 degrees C was observed by hydrophobic chromatography, using alkyl-Sepharose columns. It seems that the binding of plasma fibronectin to alpha-elastin involves hydrophobic interaction, which is affected by temperature and possibly by other factors.

Chromatography, Affinity↗
PubMed1991

Increased gene expression of matrix metalloproteinase-3 (stromelysin) in skin fibroblasts from patients with severe recessive dystrophic epidermolysis bullosa.

Gene expression of matrix metalloproteinase 3 (MMP-3 = stromelysin) was examined in the skin fibroblasts obtained from patients with severe recessive dystrophic epidermolysis bullosa (RDEB). Steady-state mRNA level of MMP-3 was selectively increased in the unstimulated RDEB cells by a post-transcriptional mechanism. A parallel study on the susceptibility of type VII collagen to MMPs revealed that this type of collagen is degraded by MMP-3, but not by MMP-1 (collagenase). These data suggest that MMP-3 may play an important role in the blister formation fo the skin in RDEB patients by the degradation of anchoring fibrils consisting of type VII collagen.

Blotting, Northern↗
PubMed1990

Effects of reduced malto-oligosaccharides on the thermal stability of pullulanase from Bacillus acidopullulyticus.

We investigated the effects of the reduced malto-oligosaccharides, D-glucitol (G1-OH), maltitol (G2-OH), maltotriitol (G3-OH), maltotetraitol (G4-OH), and maltopentaitol (G5-OH) on the thermal stability of Bacillus acidopullulyticus pullulanase (EC 3.2.1.41). The thermal stability depended on the concentration of D-glucitol; after heat treatment for 90 min at 60 degrees in the presence of 0.56, 0.28, 0.14, or 0M G1-OH, the residual activity was 100, 80, 32, and 10% of the control, respectively. Stability increased with the number of glucosyl residues in the alditols added; the effects of G3-OH, G4-OH, and G5-OH on stability were remarkable. Addition of 30% G2-OH, G3-OH, and G4-OH also contributed to the thermal stability of the pullulanase immobilized onto chitosan beads treated with glutaraldehyde. A high concentration of G2-OH stabilized other debranching amylases, Klebsiella pneumoniae pullulanse, Bacillus sectorramus pullulanase, and Pseudomonas amyloderamosa isoamylase (EC 3.2.1.68) under heat treatment for 48 h at 60 degrees, as well as the pullullanase of B. acidopullulyticus.

Amylases↗
PubMed1990

Nonenzymatic glycation alters properties of collagen as a substratum for cells.

Acid-soluble collagen from rat skin was glycated in vitro by incubating with 0.2 M D-ribose at 37 degrees C for several days, and properties of the glycated collagen as a substratum for fibroblasts 3 Y 1 were studied. The cells attached but spread poorly on the glycated collagen as compared with on the untreated collagen. Thymidine incorporation by the cells on the glycated collagen was higher than that by the cells on untreated collagen. These results indicate that the glycation significantly alters properties of collagen as a substratum for cells.

Animals↗
PubMed1989

Cell-adhesive immunoglobulin M in human plasma.

Human plasma contains a cell-adhesive protein that has a structure related to immunoglobulins. This protein was purified by affinity chromatography on an elastin-Sepharose column and by Mono Q anion-exchange chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis under non-reducing and reducing conditions revealed that this protein is a kind of immunoglobulin M (IgM). Antibodies against the mu chain and against the Fc region of IgM inhibited the adhesion of cells to this protein. Addition of the peptide GRGDS into media inhibited the adhesion, too. These results suggest that this protein is a special subset of IgM having a cell-binding sequence in the Fc region. We propose the name "cell-adhesive immunoglobulin M (CA-IgM)" for this protein. CA-IgM binds to alpha-elastin and laminin suggesting that it may play a role in the interaction between cells and the extracellular matrix.

Animals↗
PubMed1987

Detection of the cross-linking amino acid, histidinoalanine, in human brown cataractous lens protein.

In human nuclear cataract, with its progression, high polymers protein mass, which is aggregated and strengthened by disulfide cross-links and other covalent cross-links, accumulates in the nuclear region to cause hardening of the lens nucleus. However, the structure of non-disulfide covalent cross-links has not been clearly confirmed yet. Recently a cross-linking amino acid, histidinoalanine, was discovered in connective tissue and is thought to cause hardening of the tissue with aging. The content of this amino acid in the lens nucleus was studied. Nuclear cataract was classified on the basis of nuclear color as described by Pirie (1986). The content of histidinoalanine was found to be 0.05 +/- 0.03 nmol mg-1 in normal nucleus; 0.06 +/- 0.03 nmol mg-1 in grade I (uniform pale yellow); 0.05 +/- 0.03 nmol mg-1 in grade II (deep yellow nucleus); 0.38 +/- 0.07 nmol mg-1 (P less than 0.01) in grade III (hazel-brown nucleus) and 3.35 +/- 2.76 nmol mg-1 (P less than 0.01) in grade IV (deep brown nucleus). The result suggests that histidinoalanine is one of the non-disulfide cross-links of lens proteins in nuclear cataract and is closely related to the grade of cataract.

Adult↗
PubMed1987

Cross-linking of collagen by ascorbate-copper ion systems.

Cross-linking occurred rapidly in collagen when it was treated with ascorbate-copper ion systems. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic patterns of CNBr peptides suggest that in some respects the modifications by the ascorbate-copper ion systems mimicked those that occurred in collagen with aging.

Animals↗
PubMed1986

The relationship between trypsin activity in amniotic fluid and premature rupture of membranes.

Trypsin activity and concentration of alpha 1-antitrypsin in amniotic fluid were measured in patients with and without premature rupture of membranes. Trypsin activity in amniotic fluid with premature rupture of membranes (127 +/- 57 U/L) was found to be significantly higher than in cases without premature rupture of membranes (14 +/- 20 U/L) (p less than 0.01). The concentration of alpha 1-antitrypsin in amniotic fluid with premature rupture of membranes (6.8 +/- 5.5 mg/dl) was significantly lower than in cases without premature rupture (25.2 +/- 20.2 mg/dl) (p less than 0.01). Trypsin activity and concentration of alpha 1-antitrypsin in amniotic fluid were not influenced by rupture of membranes and labor. These studies suggest that high trypsin activity and low concentration of alpha 1-antitrypsin in amniotic fluid is one cause of premature rupture of membranes.

Amnion↗
PubMed1986

Effect of calcium deficiency on the content of nonreducible crosslinks in rat mandibular bone.

The effect of calcium deficiency on the content of the nonreducible cross-linking amino acid, pyridinoline, in rat mandibular bone was studied. An apparent decrease in serum and bone calcium levels was observed beginning at four weeks after initiation of a calcium-deficient diet. The pyridinoline content in the bone of calcium-deficient animals began to increase at four weeks and thereafter increased markedly as compared to that of controls. Collagen content increased significantly six weeks after calcium deficiency. These results suggest that calcium deficiency inhibits mineralization and promotes the formation of pyridinoline in rat mandibular bone.

Amino Acids↗
PubMed1986

Histidinoalanine in human urine.

Histidinoalanine, a cross-linking component of connective tissue proteins, was detected in the acid hydrolysate of human urine. The concentrations in urines from newborn babies, children, and adults were 1.33 +/- 0.27, 0.77 +/- 0.23, and 0.89 +/- 0.33 nmol/mg creatinine, respectively. Possible origins of urinary histidinoalanine are discussed.

Adolescent↗
PubMed1986

A cell-binding, immunoglobulin-like protein from human plasma. I. Isolation and subunit structure.

A protein having Mr of more than 900K (900,000) was isolated by chromatography on a column of Sepharose 4B coupled with solubilized elastin, followed by sucrose density gradient centrifugation. The protein is composed of several disulfide-linked subunits. SDS-polyacrylamide gel electrophoresis and immunoblotting indicated that two of the subunits are identical with the heavy chains of IgM and IgG, and one is immunologically related to the heavy chain of IgA. The results suggested that this protein is a new protein that belongs to the category of, or is closely related to, the immunoglobulins. As described in the succeeding paper, it has cell-binding activity (Fukamizu et al. (1986) J. Biochem. 100, 843-848). We tentatively refer to this protein as "cell-binding immunoglobulin-like protein (CIP)."

Amino Acids↗
PubMed1986

A cell-binding, immunoglobulin-like protein from human plasma. II. Cell-binding activity.

Cell adhesion to plastic surfaces coated with a new high-molecular-mass immunoglobulin-like protein from normal human plasma was studied. Mouse subdermal fibroblasts, hamster kidney cells, human umbilical vein endothelial cells, and human skin fibroblasts were found to become attached to the surface, but cancer cells derived from human stomach cancer and human breast cancer did not. The appearance of the attached cells differed from that of cells attached to surfaces coated with fibronectin or concanavalin A. The cell adhesion to the surfaces coated with the protein was inhibited by goat anti-human IgM. Furthermore, the binding of the protein to the cell surfaces was demonstrated by the indirect immunofluorescence method. It is concluded that this protein is a new cell-binding protein.

Animals↗
PubMed1985

Collagen types in normal and prematurely ruptured amniotic membranes.

Collagen content in preterm amnions with premature rupture of the membranes was significantly lower than that of preterm amnions without premature rupture of the membranes. Collagen types were studied through sodium dodecyl sulfate-polyacrylamide gel electrophoresis in human amnions from pregnant women with or without premature rupture of the membranes. Collagen types I, III, and V were recognized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in all samples. In samples taken from preterm patients with premature rupture of the membranes, the ratios of III/I, III/V, and III/total collagen were significantly lower than those from ones without premature rupture of the membranes. The ratios of I/V, I/total collagen, and V/total collagen showed no change in gestations with and without premature rupture of the membranes, respectively. In term samples there was no significant difference in the ratios of all collagen types between those with and those without premature rupture of the membranes. Elastins were not demonstrable in amnion with and without premature rupture of the membranes. These studies suggest that the reduction of type III collagen content in amnion is related to the cause of premature rupture of the membranes, particularly in preterm samples.

Adult↗