-
[show abstract]
[hide abstract]
ABSTRACT: Control of the in vitro spatiotemporal availability of calcium ions is one means by which the microenvironments of hematopoietic stem cells grown in culture may be reproduced. The effects of cross-linking density on the diffusivity of calcium ions through cell culture compatible poly(2-hydroxyethyl methacrylate) [poly(HEMA)]-based bioactive hydrogels possessing 1.0 mol% 2-methacryloyloxyethyl phosphorylcholine (MPC), 5 mol% N,N-(dimethylamino)ethylmethacrylate (DMAEMA) and ca. 17 mol% n-butyl acrylate (n-BA) have been investigated to determine if varying cross-link density is a viable approach to controlling transport of calcium across hydrogel membranes. Cross-linking density was varied by changing the composition of cross-linker, tetraethyleneglycol diacrylate (TEGDA). The hydrogel membranes were formed by sandwich casting onto the external surface of track-etched polycarbonate membranes (T = 10 μm, φ = 0.4 μm pores) of cell culture inserts, polymerized in place by UV light irradiation and immersed in buffered (0.025 HEPES, pH 7.4) 0.10 M calcium chloride solution. The transport of calcium ions across the hydrogel membrane was monitored using a calcium ion selective electrode set within the insert. Degree of hydration (21.6 ± 1.0%) and void fraction were found to be constant across all cross-linking densities. Diffusion coefficients, determined using time-lag analysis, were shown to be strongly dependent on and to exponentially decrease with increasing cross-linking density. Compared to that found in buffer (2.0-2.5 × 10⁻⁶ cm²/s), diffusion coefficients ranged from 1.40 × 10⁻⁶ cm²/s to 1.80 × 10⁻⁷ cm²/s and tortuosity values ranged from 1.7 to 10.0 for the 1 and 12 mol% TEGDA cross-linked hydrogels respectively. Changes in tortuosity arising from variations in cross-link density were found to be the primary modality for controlling diffusivity through novel n-BA containing poly(HEMA)-based bioactive hydrogels.
Biomedical Microdevices 03/2012; 14(3):549-58. · 3.03 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Indoxyl sulfate (IS) is an organic anion uremic toxin that accumulates in patients with chronic kidney disease (CKD). The aims of this study were to examine the kinetic profiles of IS in humans at a steady state after multiple doses of L-Trp, a precursor of IS, and the in vivo interaction of IS with the angiotensin-converting enzyme inhibitor quinapril, whose active metabolite is a substrate of organic anion transporter 3 (OAT3) in rats. First, 12-h kinetics after single doses of Trp (2, 4, and 8 g) were examined in two healthy volunteers. Second, 24-h kinetics after a single dose of 2 g of Trp was studied in six volunteers. Third, 35-h kinetics after single and multiple doses of 2 g of Trp were examined in five volunteers. In anesthetized rats, quinapril or probenecid, an inhibitor of OATs, was given intravenously before IS, and blood and urine samples were taken until 90 min. Trp and IS concentrations were determined by high-performance liquid chromatography. Ultrafiltration was used to measure serum unbound IS concentrations. Renal tubular secretion of IS accounted for more than 90% of its renal clearance in the steady state of serum IS levels after multiple doses in humans. In animals, the serum area under the curve of IS increased in conjunction with a decrease in renal clearances after coadministration of IS with quinapril or probenecid. It is concluded that quinapril may inhibit the urine excretion of IS via OAT3-mediated renal tubular transport in patients with CKD.
Journal of Pharmacology and Experimental Therapeutics 03/2012; 341(3):626-33. · 3.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The intestinal parasitic nematode Nippostrongylus brasiliensis is expelled rapidly from the rat in reinfection challenge compared with that of the primary infection owing to the host defense mechanisms raised against the pre-intestinal- and intestinal-stage larvae. We examined the relationship between the mucin alterations in airway and jejunal mucosae and the worm expulsion after third-stage larva reinfection. When rats had been inoculated with fourth-stage larvae and immunized with only the intestinal-stage worms for more than 8 days, the challenge larvae were expelled during the intestinal stage along with a rapid increase of the specific sialomucin in jejunal mucosa, without any effect on the bronchial mucus. When rats had been infected with third-stage larvae and immunized with only the pre-intestinal stage larvae by killing with antihelminthic, the challenge larvae were rejected during the pre-intestinal stage along with marked goblet cell hyperplasia and Muc5AC mucin hyperproduction on the bronchial mucosa, but not as a result of jejunal mucin alteration. Taking these finding together, immunization with pre-intestinal- and intestinal-stage worms independently increases the airway and intestinal goblet cell mucins, respectively, and in both cases, the mucin alterations may contribute to rapid worm expulsion upon reinfection.
Experimental Parasitology 03/2012; 130(3):209-17. · 2.12 Impact Factor
-
Fumitoshi Karasawa,
Akira Shiota,
Yukinobu Goso,
Motohiro Kobayashi,
Yoshiko Sato,
Junya Masumoto,
Maiko Fujiwara,
Shuichi Yokosawa,
Takashi Muraki,
Shinichi Miyagawa,
Masatsugu Ueda,
Michiko N Fukuda,
Minoru Fukuda, Kazuhiko Ishihara,
Jun Nakayama
[show abstract]
[hide abstract]
ABSTRACT: Gastric gland mucin secreted from the lower portion of the gastric mucosa contains unique O-linked oligosaccharides (O-glycans) having terminal α1,4-linked N-acetylglucosamine residues (αGlcNAc). Previously, we identified human α1,4-N-acetylglucosaminyltransferase (α4GnT), which is responsible for the O-glycan biosynthesis and characterized αGlcNAc function in suppressing Helicobacter pylori in vitro. In the present study, we engineered A4gnt(-/-) mice to better understand its role in vivo. A4gnt(-/-) mice showed complete lack of αGlcNAc expression in gastric gland mucin. Surprisingly, all the mutant mice developed gastric adenocarcinoma through a hyperplasia-dysplasia-carcinoma sequence in the absence of H. pylori infection. Microarray and quantitative RT-PCR analysis revealed upregulation of genes encoding inflammatory chemokine ligands, proinflammatory cytokines, and growth factors, such as Ccl2, Il-11, and Hgf in the gastric mucosa of A4gnt(-/-) mice. Further supporting an important role for this O-glycan in cancer progression, we also observed significantly reduced αGlcNAc in human gastric adenocarcinoma and adenoma. Our results demonstrate that the absence of αGlcNAc triggers gastric tumorigenesis through inflammation-associated pathways in vivo. Thus, αGlcNAc-terminated gastric mucin plays dual roles in preventing gastric cancer by inhibiting H. pylori infection and also suppressing tumor-promoting inflammation.
The Journal of clinical investigation 03/2012; 122(3):923-34. · 15.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The layer-by-layer (LBL) construction of an enzyme electrode covered with a multilayer structure alternately composed of a polymeric electron transfer mediator and a polymer-modified enzyme was examined. Poly(2-methacryloyloxyethyl phosphorylcholine-co-p-vinylphenylboronic acid-co-vinylferrocene) (PMVF) was synthesized and used as a polymeric electron transfer mediator. Glucose oxidase (GOx) was selected as a model enzyme and poly(vinyl alcohol) (PVA) chains were bound to the GOx (GOx-PVA) under mild conditions. The PMVF and PVA formed a gel spontaneously through a selective reaction between phenylboronic acid units and hydroxyl groups in both polymers. Using the spin coating technique, a repeating PMVF/GOx-PVA multilayer was fabricated on the surface of an Au electrode. The thickness of each PMVF/GOx-PVA layer was around 5.8 nm, corresponding to the dimensions of GOx. The electrochemical performance of the electrode was evaluated in glucose concentration measurement. The oxidation current of glucose by GOx was measured at 0.38 V (vs. Ag/AgCl), verifying that ferrocene units in the PMVF of the hydrogel electrically wired the immobilized GOx. Moreover, the current increased with the number of PMVF/GOx-PVA layers. That is, both intermolecular electron transfer between each individual layer and the presence of a freely diffusing substrate in the hydrogel were achieved. We conclude that a LBL structure constructed from PMVF and a PVA-modified enzyme is effective for use in developing bioelectronic devices that employ enzyme molecules.
Biosensors & bioelectronics 02/2012; 34(1):191-6. · 5.43 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Low-dose aspirin is known to cause upper gastrointestinal complications. The mechanism by which the aspirin disrupts gastric mucosal integrity remains to be clarified. In this study we investigated the temporal association of gastric secretory parameters (acid and mucus) with aspirin-induced gastropathy.
In 42 long-term low-dose aspirin-takers and the same number of sex- and age-matched controls, pentagastrin-stimulated gastric juice was collected for 10 min during endoscopic examination. The collected gastric juice was divided and half was submitted to analysis for gastric acid (mEq/10 min) and the other half was analyzed for mucin (mg hexose/10 min) output. The grade of gastric mucosal injury was assessed endoscopically according to the modified Lanza score, and a score of more than 4 was defined as the presence of severe gastropathy.
While gastric acid secretion did not differ significantly between aspirin-takers and controls, gastric mucus secretion, in terms of mucin output, was significantly increased in aspirin-takers compared to controls (4.1 (SD 4.8) vs. 2.3 (1.4) mg hexose/10 min, P < 0.05). Consequently, the acid/mucin ratio was significantly decreased in aspirin-takers compared to controls (1.2 (1.0) vs. 1.7 (1.4), P < 0.05). In the subanalysis of 25 aspirin-takers without severe gastropathy, gastric mucus secretion was increased and the acid/mucus ratio was decreased compared with controls, but there was no such association in the remaining 17 aspirin-takers with severe gastropathy.
Overall, gastric mucus secretion is increased in aspirin-takers, suggesting a functional adaptive response to long-term administration of the drug. However, it is possible that the adaptive response is impaired in some aspirin takers, who might be susceptible to severe upper gastrointestinal complication.
Journal of Gastroenterology 02/2012; 47(2):150-8. · 4.16 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A neutral cysteine protease, bleomycin hydrolase (BH), is widely expressed in mammalian tissues, with the skin seeming to contain the highest level. Our previous study revealed that BH transcription is modulated both during differentiation and by cytokines. However, BH involvement in keratinization disorder is not well known. In the present study, we performed immunohistochemical studies of BH and other serine/cysteine proteases in human normal skin and lesional skin with keratinization disorders. BH-positive cells were detected in granular layers of orthokeratotic and hyperkeratotic skin diseases, such as erythrokeratoderma and lichen planus. In parakeratotic skin diseases with porokeratosis, pityriasis rubra pilaris and psoriasis, BH staining was decreased in lesional skins compared to that in normal skin. Similar results were obtained for cysteine proteases, caspase-14 and calpain I. On the other hand, cells positive for serine proteases kallikrein 5 and 7 were increased in parakeratotic and inflammatory skin diseases, such as psoriasis. Semi-quantification analysis revealed that BH- and caspase-14-positive staining had higher intensity than those of the other proteases in normal epidermis. As BH is the major citrulline aminopeptidase in normal granular layer, the alternation would have a significant effect on terminal differentiation processes, such as aberrant processing of deiminated peptides. Therefore, BH may play an important role during the late stage of epidermal differentiation.
Archives for Dermatological Research 01/2012; 304(1):31-8. · 2.28 Impact Factor
-
Daigo Tsubokawa,
Yukinobu Goso,
Rei Kawashima,
Hiroyoshi Ota,
Takeshi Nakamura,
Kazuo Nakamura,
Noriko Sato,
Makoto Kurihara,
Taeko Dohi,
Yuki I Kawamura,
Takafumi Ichikawa, Kazuhiko Ishihara
[show abstract]
[hide abstract]
ABSTRACT: Rat small intestinal goblet cell mucins reacting with monoclonal antibody HCM31 increase significantly during regeneration from experimental mucosal damage and at the period of expulsion of parasitic nematode, Nippostrongylus brasiliensis (N.b). The reduction in reactivity of HCM31 with mucin upon neuraminidase treatment, suggested that HCM31 recognizes sialylated oligosaccharide on mucin. HCM31-reactive sialomucins are therefore considered to play an important role in the physiological and pathological changes in the gastrointestinal mucosa. To determine the epitope for HCM31, oligosaccharide-alditols reacted with HCM31 were obtained from the small intestinal mucins of N.b-infected rats and purified by ion-exchange chromatography followed by normal-phase HPLC. Two HCM31-reactive oligosaccharide-alditols were obtained. Analyses using tandem mass spectrometry and NMR spectroscopy showed that these oligosaccharides were core 4 mucin-type oligosaccharides having a common tetrasaccharide sequence, NeuAcα2-3(GalNAcβ1-4)Galβ1-4GlcNAcβ- (Sd(a) blood group antigen). These structures were not found in the small intestinal mucin oligosaccharides from uninfected rats. This epitope specificity of HCM31 was also confirmed using previously established anti-GM2 and anti-Sd(a) antibodies. Taken together, these results strongly suggest that HCM31 specifically recognizes mucin-type oligosaccharides with the Sd(a) tetrasaccharide sequence. Immunohistochemical examination of human gastrointestinal tracts showed that HCM31 site-specifically stained the goblet cells in normal sigmoid colon and normal rectum, but the goblet cells stained with HCM31 were reduced in the corresponding cancer tissues. HCM31 seems to be useful for diagnosis of colonic cancer and for examining the function of secretory-type mucin with Sd(a) antigen.
FEBS open bio. 01/2012; 2:223-33.
-
[show abstract]
[hide abstract]
ABSTRACT: Compared with the aggressive factors, little attention has been paid to the mucosal defensive factors in ulcer therapy, and the role of the H2-receptor antagonists in gastric mucosal protection has not been well characterized. In the present study, the effects of different types of H2-receptor antagonists (famotidine and roxatidine) on rat gastric mucus cells were investigated using both biochemical and histological methods. Each drug (famotidine, 3 mg/kg; roxatidine, 100 mg/kg) was orally administered to rats by gavage once daily for 7 days. The biosynthesis and tissue content of mucin were compared in the gastric mucosa treated with each drug. Using anti-mucin monoclonal antibodies, the mucin content and immunohistochemical localization were also compared. Both the biosynthesis and the accumulation of gastric mucin were significantly decreased in the famotidine-treated rats, but not in the roxatidine. Both the content and the immunoreactivity of surface mucus cell-derived mucin were reduced by famotidine, while they were maintained in roxatidine-treated rat stomachs. There was no difference between the groups in the content and immunoreactivity of mucous neck cell-derived mucin. H2-receptor antagonists should be classified in relation to gastric surface mucus cell function, raising the possibility of more effective ulcer therapy.
Biomedical Research 01/2012; 33(1):45-51. · 1.15 Impact Factor
-
09/2011; , ISBN: 978-953-307-375-0
-
[show abstract]
[hide abstract]
ABSTRACT: Loss-of-function mutation in the profilaggrin gene is a major risk factor for atopic dermatitis (AD). Previously, we showed
that a neutral cysteine protease, bleomycin hydrolase (BH), has a role in generating natural moisturizing factors, and calpain
I is an upstream protease in the filaggrin degradation pathway. Here, we investigated the transcriptional regulatory mechanisms
of BH and the relevance of BH to AD. First, we cloned the 5′-flanking region of BH. Deletion analyses identified a critical
region for BH promoter activity within −216 bp upstream. Electrophoretic mobility shift assay revealed that MZF-1, Sp-1, and
interferon regulatory factor-1/2 could bind to this region in vitro. Moreover, site-directed mutagenesis of the MZF-1 and Sp-1 motifs markedly reduced BH promoter activity. These data indicate
that BH expression is up-regulated via MZF-1 and Sp-1. Interestingly, a Th1 cytokine, IFN-γ, significantly reduced the expression
of BH. Analyses with site-directed mutagenesis and small interference RNA supported the suppressing effect of IFN-γ on BH
expression. On the other hand, a Th2 cytokine, IL-4, did not show any direct effect on BH expression. However, it down-regulated
MZF-1 and Sp-1 in cultured keratinocytes, indicating that IL-4 could work as a suppressor in BH regulation. Lastly, we examined
expression of BH in skins of patients with AD. BH activity and expression were markedly decreased in AD lesional skin, suggesting
a defect of the filaggrin degradation pathway in AD. Our results suggest that BH transcription would be modulated during both
differentiation and inflammation.
Journal of Biological Chemistry 03/2011; 286(10):8204-8212. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Nonsteroidal anti-inflammatory drugs induce small intestinal ulcers but the preventive measures against it remain unknown. So we evaluated the effect of geranylgeranylacetone (GGA), a mucosal protectant, on both the mucus content and loxoprofen sodium-induced lesions in the rat small intestine. Normal male Wistar rats were given GGA (200 or 400mg/kg p.o.) and euthanized 3h later for measurement of mucin content and immunoreactivity. Other Wistar rats were given loxoprofen sodium (30mg/kg s.c.) and euthanized 24h later. GGA (30-400mg/kg p.o.) was administered twice: 30min before and 6h after loxoprofen sodium. The total mucin content of the small intestinal mucosa increased, especially the ratio of sialomucin, which increased approximately 20% more than the control level after a single dose of GGA. Loxoprofen sodium provoked linear ulcers along the mesenteric margin of the distal jejunum, accompanied by an increase in enterobacterial translocation. Treatment of the animals with GGA dose-dependently prevented the development of intestinal lesions, and bacterial translocation following loxoprofen sodium was also significantly decreased. GGA protects the small intestine against loxoprofen sodium-induced lesions, probably by inhibiting enterobacterial invasion of the mucosa as a result of the increase in the mucosal barrier.
European journal of pharmacology 02/2011; 652(1-3):121-5. · 2.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Loss-of-function mutation in the profilaggrin gene is a major risk factor for atopic dermatitis (AD). Previously, we showed that a neutral cysteine protease, bleomycin hydrolase (BH), has a role in generating natural moisturizing factors, and calpain I is an upstream protease in the filaggrin degradation pathway. Here, we investigated the transcriptional regulatory mechanisms of BH and the relevance of BH to AD. First, we cloned the 5'-flanking region of BH. Deletion analyses identified a critical region for BH promoter activity within -216 bp upstream. Electrophoretic mobility shift assay revealed that MZF-1, Sp-1, and interferon regulatory factor-1/2 could bind to this region in vitro. Moreover, site-directed mutagenesis of the MZF-1 and Sp-1 motifs markedly reduced BH promoter activity. These data indicate that BH expression is up-regulated via MZF-1 and Sp-1. Interestingly, a Th1 cytokine, IFN-γ, significantly reduced the expression of BH. Analyses with site-directed mutagenesis and small interference RNA supported the suppressing effect of IFN-γ on BH expression. On the other hand, a Th2 cytokine, IL-4, did not show any direct effect on BH expression. However, it down-regulated MZF-1 and Sp-1 in cultured keratinocytes, indicating that IL-4 could work as a suppressor in BH regulation. Lastly, we examined expression of BH in skins of patients with AD. BH activity and expression were markedly decreased in AD lesional skin, suggesting a defect of the filaggrin degradation pathway in AD. Our results suggest that BH transcription would be modulated during both differentiation and inflammation.
Journal of Biological Chemistry 12/2010; 286(10):8204-12. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The location of mucosal damage and changes in mucin content in the rat small intestine following administration of non-steroidal anti-inflammatory drugs (NSAIDs) have not been well elucidated.
After subcutaneous administration of loxoprofen sodium (10-40 mg/kg), the small intestinal mucosa of male Wistar rats was evaluated macroscopically, histologically, and immunohistochemically by measuring the total mucin content and immunoreactivity for anti-mucin monoclonal antibody, HCM31, 1, 3, 7, and 14 days later. Changes in the number of enterobacteria invading the mucosa around the lesions were also determined.
Loxoprofen sodium induced erosions and ulcers along the mesenteric margin of the distal jejunum. Early (≤6 h) mucosal lesions were small and round, located between the branches of the mesenteric arteries. In the jejunum, there was a transient increase in the total mucin content, and HCM31-positive mucin in the mucosa around the ulcers increased significantly on days 3 and 7, but in the ileum there were no marked changes and few ulcers. Bacterial translocation following loxoprofen sodium administration significantly increased, according to the site of the intestinal lesions.
Vascularly compromised sites along the jejunal mesenteric margin are vulnerable to NSAIDs-induced damage and show increased numbers of enterobacteria in the NSAIDs-treated mucosa. Increased sialomucin content in the mucus around the lesions may play an important role in the healing of NSAIDs-induced intestinal lesions.
Digestive Diseases and Sciences 03/2010; 55(12):3369-76. · 2.12 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Unlike the earlier agents in this class, certain of the newer histamine H(2)-receptor antagonists (so-called second-generation HB(2B)-receptor antagonists) have recently been reported to promote gastric mucosal defenses. We review herein the structure, specificity, and mechanisms of these agents with a special focus on their cytoprotective/gastroprotective actions.
Mini Reviews in Medicinal Chemistry 06/2009; 9(5):581-9. · 2.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The luminal surface of the gastrointestinal tract is covered by a viscoelastic gel layer that acts as a protective barrier against the intraluminal environment. Because the situation of the small intestine has not been elucidated to the same degree as other sections, in this study, we investigated the effects of indomethacin on the rat small intestinal mucosa.
Male Wistar rats were given indomethacin 10 mg/kg s-c and sacrificed 1, 3, 7, or 14 days later. The small intestine was opened along the anti-mesenteric side, and examined macroscopically. Total mucin content in the small intestinal epithelium was measured and immunoreactivity was examined using anti-mucin monoclonal antibodies HCM31 and PGM34.
Indomethacin caused punched out and linear ulcers located mostly along the mesenteric margin of the distal jejunum with sparing of the ileum. Histological examination showed sialomucin recognized by HCM31 increased on day 3 especially in the regenerating epithelium around the ulcer edge. Furthermore, the surface mucous gel layer displayed a multilaminated pattern, consisting of non-sulfated sialomucin-rich layers and sulfated mucin-rich layers, where both mucins had the common core protein, MUC2. Biochemical measurements also showed the total mucin content of the jejunum increased transiently and HCM31-positive mucin increased approximately 4 times greater than baseline on day 3, but no marked changes were observed in the ileum, with few ulcers observed.
Indomethacin administration causes quantitative and qualitative change in jejunal mucin. In particular, sialomucin plays an important role in regenerating epithelium during the healing process following indomethacin-induced mucosal damage.
Journal of Gastroenterology 04/2009; 44(4):277-84. · 4.16 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Filaggrin is a component of the cornified cell envelope and the precursor of free amino acids acting as a natural moisturizing factor in the stratum corneum. Deimination is critical for the degradation of filaggrin into free amino acids. In this study, we tried to identify the enzyme(s) responsible for the cleavage of deiminated filaggrin in vitro. First, we investigated citrulline aminopeptidase activity in the extract of newborn rat epidermis by double layer fluorescent zymography and detected strong activity at neutral pH. Monitoring the citrulline-releasing activity, we purified an enzyme of 280 kDa, comprised of six identical subunits of 48 kDa. The NH(2) terminus of representative tryptic peptides perfectly matched the sequence of rat bleomycin hydrolase (BH). The enzyme released various amino acids except Pro from beta-naphthylamide derivatives and hydrolyzed citrulline-beta-naphthylamide most effectively. Thus, to break down deiminated filaggrin, another protease would be required. Among proteases tested, calpain I degraded the deiminated filaggrin effectively into many peptides of different mass on the matrix-assisted laser desorption/ionization-time of flight mass spectrum. We confirmed that various amino acids including citrulline were released by BH from those peptides. On the other hand, caspase 14 degraded deiminated filaggrin into a few peptides of limited mass. Immunohistochemical analysis of normal human skin revealed co-localization of BH and filaggrin in the granular layer. Collectively, our results suggest that BH is essential for the synthesis of natural moisturizing factors and that calpain I would play a role as an upstream protease in the degradation of filaggrin.
Journal of Biological Chemistry 04/2009; 284(19):12829-36. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: By using commercially available anhydrous hydrazine in the gas-phase, mucin-type oligosaccharides were released from porcine gastric mucin (PGM) and bovine fetuin. The data indicated that a certain amount of the oligosaccharides from PGM were further degraded. Despite this, the HPLC elution profile of the anthranilic acid (AA)-derivatized oligosaccharides obtained by the treatment with hydrazine at 65 degrees C for 6 h resembled those obtained from the alkaline-borohydride treatment, except for the additional disaccharide fractions derived from the core 1 side of the oligosaccharides by further degradation. The other degraded products derived from the core 2 side could not be derivatized by AA, therefore, not visible by fluorescence detection. Liberation of the oligosaccharides was incomplete by the hydrazine treatment for 6 h. Although almost complete liberation was achieved by extending the treatment to 18 h, the degraded products also increased. In this case, the addition of barium oxide to the reaction vessel decreased the degree of further degradation. Results similar to PGM were obtained from bovine fetuin, but with less degradation. Application of this method for the analysis of rat gastric mucin (RGM) obtained from the corpus and antral region revealed that RGM has a large oligosaccharide portion on the core 1 side.
Journal of biochemistry 03/2009; 145(6):739-49. · 1.95 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although tea catechins are known to exert a potent antiulcer effect on the alimentary tract, there is scant information concerning their effects on normal mucus cell functions. Using original anti-mucin monoclonal antibodies, we studied the influences of long-term administration of catechins on the quantity and quality of mucin in rat gastrointestinal mucosa. Administration of 0.5% tea catechins significantly increased the mucin content of the ileum, but not the stomach. An enzyme-linked immunosorbent assay (ELISA) showed no remarkable qualitative changes in gastric mucin, but a selective increase and decrease in sulfo- and sialomucins, respectively, in the ileum of rats administered catechins. The ELISA results were consistent with both the immunohistochemical findings and the high-iron diamine-alcian blue staining pattern. These findings indicate that tea catechins modulate ileal mucin metabolism in the ileal mucosa, suggesting that further studies focusing on the ileal epithelium will assist in further elucidation of the mechanism of catechin effects.
Journal of Agricultural and Food Chemistry 12/2008; 56(24):12122-6. · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In Japan, peptic ulcer disease (PUD) is treated clinically with a combination of a mucosal protectant and acid suppressants, but there is scant information regarding the effects of these drugs on normal gastric mucus cells. In the present study, the effects of co-administration of methylmethionine sulfonium chloride (MMSC) and famotidine on rat gastric mucus cells were investigated using both biochemical and histological methods.
Rats were divided into four groups: controls were given carboxymethylcellulose orally once daily for 7 days and the second, third and fourth groups were treated similarly with famotidine (famotidine group), MMSC (MMSC group) or famotidine plus MMSC (combination group). After killing the rats on the 8th day, the stomachs were removed and the biosynthesis and amount of mucin in different areas of the gastric mucosa were compared among groups. Using anti-mucin monoclonal antibodies, the mucin content and immunoreactivity were also compared.
Both the biosynthesis and accumulation of mucin were significantly decreased in the famotidine group, but increased in the MMSC and combination groups. The amount and immunoreactivity of surface mucus cell-derived mucin were both reduced in the famotidine group, and increased in the MMSC and combination groups. There was no difference among the groups in the content and immunoreactivity of gland mucus cell-derived mucin.
Famotidine-induced suppression of gastric surface mucus cell function is prevented by combined treatment with MMSC, raising the possibility of a more effective cure of PUD.
Journal of Gastroenterology and Hepatology 11/2008; 24(3):488-92. · 2.87 Impact Factor
