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Tetsuya Endo

Publications and source records attributed to Tetsuya Endo.

At least 19 recordsLinked to original sources
PubMed2006

Matrix metalloproteinase-2, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1 in the peripheral blood of patients with various glomerular diseases and their implication in pathogenetic lesions: study based on an enzyme-linked assay and immunohistochemical staining.

BACKGROUND: Various glomerular diseases progress to end-stage renal failure due to an accumulation of the mesangial matrix (MM) and a thickening of the glomerular basement membrane (GBM). Both the MM and GBM are consistently metabolized through the synthesis and destruction of the matrix. Such synthesis is influenced by transforming growth factor-beta (TGF-beta) and other factors, whereas the destruction is presumed to be mediated by both matrix metalloproteinases (MMPs) and inhibitors of matrix metalloproteinases (TIMPs). Based on such evidence, we tried to detect MMP-2, MMP-9, and TIMP-1 in the peripheral blood of patients with various glomerular diseases. METHODS: Serum was used to detect MMP-2 and TIMP-1, while plasma was used to detect MMP-9. These enzymes were detected using an enzyme-linked assay. RESULTS: The findings showed an increased level of MMP-2 in patients with a alteration of GBM, typically membranous nephropathy (MN), regardless of the differences in their etiological processes. In contrast, MMP-9 did not show a strong association with any specific glomerular abnormalities. However, it mainly tended to increase in patients with MM accumulation. In addition, the localization of MMP-2, MMP-9, and TGF-beta1 was studied using immunohistochemical staining. MMP-2 was demonstrated to exist in the glomerular capillary loop (GCL) as well as in the mesangial cells and the mesangial matrix. MMP-9 was found to exist in mesangial cells and the matrix, GCL, infiltrated neutrophils, and some tubular epithelial cells. Positive staining for TGF-beta1 in GCL was found to be associated with an increased level of MMP-2 in patients with MN, whereas in MM such positive staining was not necessarily associated with an increased level of MMP-9. CONCLUSIONS: These results therefore suggest that MMP-2 plays an important role in the degradation of GBM, while MMP-9 only moderately affects the degradation of MM.

Enzyme-Linked Immunosorbent Assay↗
PubMed2006

Age-dependent accumulation of heavy metals in a pod of killer whales (Orcinus orca) stranded in the northern area of Japan.

Mercury (Hg), cadmium (Cd), iron (Fe) manganese (Mn), zinc (Zn) and copper (Cu) concentrations in the liver, kidney and muscle of nine killer whales (including three calves) that stranded together in the northern area of Japan were determined. The Hg and Cd concentrations were found at trace levels in the calf organs, and increased with age. The Fe concentration in the muscle was significantly lower in the calves than in the mature whales and also increased with age. In contrast, Mn and Cu concentrations in the muscle were significantly higher in the calves than in the mature whales, and changes in the Zn concentration relative to age were unclear. These results suggest minimal mother-to-calf transfer of the toxic metals Hg and Cd and accumulation of these metals in the organs with age, while the essential metals Mn and Cu were found at higher concentrations in the muscle of calves than in mature whales.

Age Factors↗
PubMed2006

Distribution of total mercury, methyl mercury and selenium in pod of killer whales (Orcinus Orca) stranded in the northern area of Japan: comparison of mature females with calves.

Total mercury (T-Hg) and selenium (Se) concentrations in liver, kidney and muscle from a pod of killer whales including five mature females and three calves stranded in the northern area of Japan were analyzed. In the mature female, contamination level of T-Hg in the liver sample (62.2+/-21.9 microg/wet g) was markedly higher than that in kidney sample and muscle sample. The molar ratio of T-Hg to Se in the liver sample was approximately 1, and those in the kidney and muscle samples were markedly lower than 1. These results suggest that the formation of HgSe compound increases the hepatic accumulation of mercury (Hg). In contrast, contamination level of T-Hg in the calf organs was much lower than that in the mature female organs. These results suggest that the transfer of Hg from the mother to the fetus via placenta and/or to calf via milk is trace.

Aging↗
PubMed2006

Characterization of Xenopus digits and regenerated limbs of the froglet.

Xenopus has 4 and 5 digits in a forelimb and hindlimb, respectively. It is thought that their limbs and digits develop in Xenopus by mechanisms that are almost conserved from amphibians to higher vertebrates. This is supported by some molecular evidence. The 5'hoxd genes are convenient marker genes for characterizing digits in the chick and mouse. The anteriormost digit is characterized by being hoxd13-positive and hoxd12 (hoxd11)-negative in the chick and mouse. In this study, we revealed that the anteriormost digit of the Xenopus forelimb is hoxd13-positive and hoxd11-positive, that is, a more posterior character than digit I. The order of formation of digit cartilages also suggested that Xenopus forelimb digit identity is II to V, not I to IV. We have also been interested in the relationship between digit identity and shh. The anteriormost digit develops in a shh-independent way. A limb treated with cyclopamine (a shh inhibitor) has a gene expression pattern (hoxd11-negative) similar to that in shh-deficient mice, suggesting that a hindlimb treated with cyclopamine has a digit I character. However, a Xenopus froglet regenerate (spike), which lacks shh expression during its regeneration process, does not have such an expression pattern, being hoxd11-positive. We investigated hoxd11 transcriptions in blastemas that formed in the anteriormost and posteriormost digits, and we found that the blastemas have different hoxd11 expression levels. These findings suggest that the froglet limb blastema does not have a mere digit I character in spite of shh defectiveness and that the froglet limb blastema recognizes its positional differences along the anterior-posterior axis.

Amino Acid Sequence↗
PubMed2006

Embryonic dermal condensation and adult dermal papilla induce hair follicles in adult glabrous epidermis through different mechanisms.

Hair induction in the adult glabrous epidermis by the embryonic dermis was compared with that by the adult dermis. Recombinant skin, composed of the adult sole epidermis and the embryonic dermis containing dermal condensations (DC), was transplanted onto the back of nude mice. The epidermis of transplants formed hairs. Histology on the induction process demonstrated the formation of placode-like tissues, indicating that the transplant produces hair follicles through a mechanism similar to that underlying hair follicle development in the embryonic skin. An isolated adult rat sole skin piece, inserted with either an aggregate of cultured dermal papilla (DP) cells or an intact DP between its epidermis and dermis, was similarly transplanted. The transplant produced hair follicles. Histology showed that the epidermis in both cases surrounded the aggregates of DP cells. The epidermis never formed placode-like tissues. Thus, it was concluded that the adult epidermal cells recapitulate the embryonic process of hair follicle development when exposed to DC, whereas they get directly into the anagen of the hair cycle when exposed to DP. The expression pattern of Edar and Shh genes, and P-cadherin protein during the hair follicle development in the two types of transplants supported the above conclusion.

Animals↗
PubMed2005

Identification, quantification, and synthesis of a novel dimethoxylated polybrominated biphenyl in marine mammals caught off the coast of Japan.

Bioaccumulation of persistent organic compounds can eventually lead to concentrations in wildlife and humans that are deleterious to health. The present paper documents the identification, quantification, and synthesis of a novel compound, 2,2'-dimethoxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diMeO-BB80), present in the marine mammals Striped dolphin (Stenella coeruleoalba), Bottlenose dolphin (Tursiops truncatus), Minke whale (Balaenoptera acutorostrata), and Baird's beaked whale (Berardius bairdii) caught in the Pacific Ocean. Identification was based on comparison of the relative retention times of the compound on two gas chromatographic columns of different polarities to those of an authentic standard. Furthermore, this identification was also supported by comparison of the full scan mass spectrometric data collected employing electron ionization (El), positive ion chemical ionization (PICI), and electron capture negative ionization (ECNI). The concentrations of 2,2'-diMeO-BB80 in the samples ranged from 12 to 800 ng/g lipid, making this consistently one of the most abundant compounds among those analyzed, including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), and methoxylated PBDEs. The known occurrence of 3,3',5,5'-tetrabromo-2,2'-biphenyldiol (2,2'-diOH-BB80) in the marine environment as a natural product suggests that its methylated derivative, 2,2'-diMeO-BB80, is also of natural origin. To obtain the necessary authentic standards, synthesis was performed of 2,2'-diMeO-BB80 and the known natural product 2',6-dimethoxy-2,3',4,5'-tetrabromodiphenyl ether (2',6-diMeO-BDE68).

Animals↗
PubMed2005

Total mercury, methyl mercury, and selenium levels in the red meat of small cetaceans sold for human consumption in Japan.

We surveyed the total mercury (T-Hg) and methyl mercury (M-Hg) levels in red meat products (n = 160) from small cetacean species sold for human consumption in markets throughout Japan from 2000 to 2003. Genetic identification showed that the red meat products originated from nine species: false killer whale, bottlenose dolphin, short-finned pilot whale, striped dolphin, rough-toothed dolphin, Risso's dolphin, pantropical spotted dolphin, Baird's beaked whale, and Dall's porpoise. T-Hg and M-Hg concentrations in all red meat products exceeded the provisional permitted levels of T-Hg (0.4 microg/wet g) and M-Hg (0.3 microg/ wet g) in fish and shellfish set by the Japanese government, respectively. The average M-Hg level in the most contaminated species (false killer whale) was 11.5 microg/wet g, and that in the least contaminated species (Dall's porpoise) was about 1.0 microg/wet g, exceeding or equaling the Codex guideline of M-Hg in predatory fishes (1.0 microg/wet g). Contamination levels of T-Hg and M-Hg differed considerably among samples of the nine species and among individuals of a particular species. The highest M-Hg was about 26 microg/ wet g in a sample from a striped dolphin, 87-times higher than the permitted level. The consumption of only 4 g of this product would exceed the provisional tolerable weekly intake of M-Hg for someone of 60 kg body weight (1.6 microg/kg-bw/ week). Although a high correlation between T-Hg and selenium (Se) was observed in these products, the molar ratio of T-Hg to Se was substantially higher than 1. The consumption of red meat from small cetaceans, therefore, could pose a health problem for not only pregnant women but also for the general population.

Animals↗
PubMed2005

Effects of P-glycoprotein inhibitors on transepithelial transport of cadmium in cultured renal epithelial cells, LLC-PK1 and LLC-GA5-COL 150.

The purpose of this study using LLC-PK(1) cells and P-glycoprotein (P-gp) overexpressed LLC-PK(1) cells (LLC-GA5-COL 150 cells) was to investigate the secretory transport of cadmium (Cd) via endogenous and overexpressed P-gp, respectively. Cell monolayers cultured on permeable membranes were incubated at 37 degrees C for 60 min with 1 microM CdCl(2) from either the apical or the basolateral side. The basolateral-to-apical transport of Cd was 1.7 times higher than the apical-to-basolateral transport of Cd in LLC-GA5-COL 150 cells, while the transport from apical and basolateral sides was almost the same in LLC-PK(1) cells. Treatment with a P-gp monoclonal antibody, UIC2, significantly decreased the basolateral-to-apical transport of Cd in LLC-PK(1) and LLC-GA5-COL 150 cells, and significantly increased the apical-to-basolateral transport of Cd in both cells. The effects of UIC2 were more marked in LLC-GA5-COL 150 cells than in LLC-PK(1) cells. Furthermore, typical P-gp inhibitors such as cyclosporin A, and doxorubicin decreased the basolateral-to-apical transport of Cd slightly in LLC-PK(1) cells and significantly in LLC-GA5-COL 150 cells. These results suggest that Cd is extruded from the apical membrane of LLC-PK(1) and LLC-GA5-COL 150 cells, probably depending on the level of P-gp expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

A stepwise model system for limb regeneration.

The amphibian limb is a model that has provided numerous insights into the principles and mechanisms of tissue and organ regeneration. While later stages of limb regeneration share mechanisms of growth control and patterning with limb development, the formation of a regeneration blastema is controlled by early events that are unique to regeneration. In this study, we present a stepwise experimental system based on induction of limb regeneration from skin wounds that will allow the identification and functional analysis of the molecules controlling this early, critical stage of regeneration. If a nerve is deviated to a skin wound on the side of a limb, an ectopic blastema is induced. If a piece of skin is grafted from the contralateral side of the limb to the wound site concomitantly with nerve deviation, the ectopic blastema continues to grow and forms an ectopic limb. Our analysis of dermal cell migration, contribution, and proliferation indicates that ectopic blastemas are equivalent to blastemas that form in response to limb amputation. Signals from nerves are required to induce formation of both ectopic and normal blastemas, and the diversity of positional information provided by blastema cells derived from opposite sides of the limb induces outgrowth and pattern formation. Hence, this novel and convenient stepwise model allows for the discovery of necessary and sufficient signals and conditions that control blastema formation, growth, and pattern formation during limb regeneration.

Ambystoma mexicanum↗
PubMed2004

Expression of MMP-9 in mesangial cells and its changes in anti-GBM glomerulonephritis in WKY rats.

BACKGROUND: Matrix metalloproteinase (MMP)-9, a member of the MMP family with specificity towards type IV collagen, is implicated in the turnover of the extracellular matrix in the kidney. To elucidate its physiological and pathophysiological significance, we examined the expression and localization of MMP-9 in the normal kidney and the changes in these features during the course of anti-glomerular basement membrane (GBM) glomerulonephritis induced in WKY rats, along with the changes in these features of tissue inhibitor of metalloproteinase 1 (TIMP-1) and MMP-2. METHODS: The expression of MMP-9, TIMP-1 and MMP-2 mRNA was quantified by ribonuclease protection assay, and the gelatinolytic activities of MMP-9 and MMP-2 were evaluated by gelatin zymography. The localization of MMP-9 was visualized by immunohistochemistry and immunofluorescence microscopy. RESULTS: The ribonuclease protection assay indicated the almost exclusive expression of MMP-9 mRNA in the glomerulus of normal kidneys. Immunohistochemistry and double-label immunofluorescence microscopy showed that MMP-9 was localized in the mesangial cells. During the course of anti-GBM glomerulonephritis, the expression of MMP-9 mRNA in glomeruli increased on day 1, peaked on days 3 to 7, and then decreased on day 14. The change in MMP-9 mRNA expression was accompanied by parallel changes in the gelatinolytic activity of the active form of MMP-9, TIMP-1 mRNA expression, and MMP-9 immunoreactivity in mesangial cells. In contrast, glomerular MMP-2 mRNA expression and its activity increased after the decline of MMP-9. CONCLUSIONS: MMP-9 mRNA was predominantly expressed in the glomerulus in normal rat kidneys and MMP-9 was present in the mesangium. The MMP-9 mRNA expression increased in the glomerulus 3 to 7 days after the induction of anti-GBM glomerulonephritis in WKY rats, in parallel with the development of abnormal glomerular histology and injury, suggesting a role of MMP-9 in proteolysis of the GBM during glomerulonephritis. MMP-2 may participate in the later phase of the nephritis.

Animals↗
PubMed2003

Renal toxicity in rats after oral administration of mercury-contaminated boiled whale livers marketed for human consumption.

Some people living in Japan have traditionally eaten the internal organs of small cetaceans (toothed whales and dolphins), and a mixed package of boiled liver, kidney, lung, and so on is still marketed for human consumption. Recently, we reported that these organs are highly contaminated with mercury. In this study, we investigated the absorption, distribution, excretion, and biochemical parameters in serum and urine after a single oral administration of boiled whale liver containing 1980 microg/g of total mercury and 23.5 microg/g of methyl mercury to rats (0.2 g boiled liver/100 g rat). The single administration of the boiled liver resulted in marked increases of the mercury concentration in the rat kidney, urinary volume, and the urinary excretion of N-acetyl-beta-D-glucosanidase, albumin, and sodium, suggesting the renal toxicity caused by inorganic mercury. Furthermore, the administration increased lactate dehydrogenase activity and creatinine, potassium, and phosphorus concentrations in serum. About 95% of total mercury dose was excreted in feces and less than 0.05% was excreted in the urine. Thus, the absorption rate of mercury from the boiled whale liver appears to be about 5% or slightly higher. These data indicate that the human consumption of boiled whale liver may cause acute intoxication by the contaminated inorganic mercury.

Administration, Oral↗
PubMed2003

Application of modified Mosher's method for primary alcohols with a methyl group at C2 position.

The absolute configurations of a series of primary alcohols possessing a branched methyl group at C2 position were examined on the basis of a modified Mosher's method proposed by Minale et al. It was revealed that in many cases the absolute configurations at C2 were assignable from the chemical shift differences of geminal protons of the methylene attached to the ester linkage in the alpha-methoxy-alpha-trifluoromethylphenylacetyl (MTPA) derivatives. The scope and limitation of this method are described.

Alcohols↗
PubMed2002

Effects of P-glycoprotein inhibitors on cadmium accumulation in cultured renal epithelial cells, LLC-PK1, and OK.

The purpose of this study was to investigate whether cadmium (Cd) efflux across the apical membrane of cultured renal epithelial cells, LLC-PK(1) and OK, is mediated via P-glycoprotein (P-gp). These cells were preincubated for 30 min with a typical P-gp inhibitor such as verapamil, diltiazem, nifedipine, vinblastine, or cyclosporin A before the incubation with 1 microM (109)CdCl(2) for 15 min. Preincubation with each P-gp inhibitor significantly increased Cd accumulation in LLC-PK(1), and OK cells. Treatment of these cells with UIC2, a P-gp monoclonal antibody, also significantly increased Cd accumulation in these cells. Thus, the pretreatment of cells with P-gp inhibitor appears to increase Cd accumulation as a result of the inhibition of Cd efflux via P-gp. To confirm Cd efflux via P-gp, Cd accumulation in P-gp-overexpressed cells (LLC-GA5-COL150 cells) was compared with that in parental LLC-PK(1) cells. LLC-GA5-COL150 cells accumulated less Cd than did LLC-PK(1) cells, and the effects of the P-gp inhibitors and UIC2 on Cd accumulation were greater in LLC-GA5-COL150 cells. These results suggest that P-gp in LLC-PK(1) and OK cells appear to act as an efflux pump of Cd, decreasing cellular Cd accumulation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Mercury and selenium concentrations in the internal organs of toothed whales and dolphins marketed for human consumption in Japan.

Small cetaceans (toothed whales odontoceti and dolphins delphinidae) have been traditionally hunted along the coast of Japan and fresh red meat and blubber, as well as boiled internal organs such as liver, kidney, lung and small intestine, are still being sold for human consumption. We surveyed mercury contamination in boiled liver, kidney and lung products marketed in Japan between 1999-2001. The average +/- S.D. of total mercury (T-Hg) was 370 +/- 525 (range: 7.60 approximately 1980, n = 26) microg/g in liver, 40.5 +/- 48.5 (7.30-95.1, n = 15) microg/g in kidney and 42.8 +/- 43.8 (2.10-79.6, n = 23) microg/g in lung. A high correlation was observed between T-Hg and selenium (Se) concentrations in these organs, supporting the formation of a Hg-Se complex. The formation of a Hg-Se complex probably contribute to the detoxification of Hg for cetaceans and allows a very large accumulation of Hg in livers. The provisional permitted level of T-Hg in marine foods set by the Japanese Ministry of Health and Welfare is 0.4 microg/ g, and the provisional permitted weekly intake (PTWI) set by WHO is 5 microg/kg bw/week. The maximal T-Hg detected in boiled liver (1,980 microg/g) exceeds the permitted level by approximately 5,000 times and the consumption of only 0.15 g of liver exceeds the PTWI of 60 kg of body weight of the consumer, suggesting the possibility of an acute intoxication by T-Hg even after a single consumption of the product.

Animals↗
PubMed2002

Effects of extract of Ginkgo biloba leaves and its constituents on carcinogen-metabolizing enzyme activities and glutathione levels in mouse liver.

The effects of a standardized extract of Ginkgo biloba L. leaves (EGb) and its terpene constituents, bilobalide and ginkgolides, on the activities of detoxification enzymes, i.e., glutathione S-transferases (GSTs) and DT-diaphorase, and glutathione contents, were investigated in the mouse liver. Oral treatment with EGb (100-1,000 mg/kg) and bilobalide (10-30 mg/kg) once a day for 4 days caused a dose-dependent elevation in GST activity. Ginkgolide A (30 mg/kg, for 4 days) also significantly elevated GST activity, whereas ginkgolide B and ginkgolide C at the same dose had no effects. EGb significantly increased the protein level of GST pi, and bilobalide significantly increased those of GST alpha and GST mu Moreover, EGb-treatment and bilobalide-treatment caused significant elevations in DT-diaphorase activity and in hepatic glutathione contents.

Animals↗