Naoki Maruyama

Tokyo Metropolitan Institute, Edo, Tōkyō, Japan

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Publications (175)622.95 Total impact

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    ABSTRACT: The objectives of this study are to investigate the prevalence of PAD4 and anti-PAD4 antibodies (Abs) in autoimmune diseases and to clarify their association with anticitrullinated protein antibodies (ACPAs) and shared epitope (SE) in patients with rheumatoid arthritis (RA). Levels of human PAD4 and anti-PAD4 Abs in serum or plasma were measured using sandwich ELISA. Samples were obtained from patients with RA (n = 148), SLE (n = 36), or SS (n = 37) and from healthy controls (HCs; n = 40). Antibodies against cyclic citrullinated glucose-6-phosphate isomerase (GPI) (CCG)-2, CCG-7, anti-CEP-1, and anti-CCP Abs were also measured using ELISA. Patients with RA were genotyped for HLA-DRB1. The human PAD4 and anti-PAD4 Ab levels were compared with the ACPA and SE in patients with RA. The PAD4 levels were 111.9 U/ml in the RA, 30.4 U/ml in the SLE, 81.9 U/ml in the SS patients, and 46.6 U/ml in the HCs. The PAD4 levels were significantly higher in the RA than in the SLE patients or the HCs. Anti-PAD4 Abs were detected in 29.7 % of the patients with RA, but not in the patients with SLE or SS, nor in the HCs. In the RA patients, the PAD4 levels in the anti-PAD4 Ab-negative group were significantly higher than those in the anti-PAD4 Ab-positive group. Moreover, anti-CCG-2, CCG-7, CEP-1, and anti-CCP Ab levels were significantly higher in the anti-PAD4 Ab-positive group than in the anti-PAD4 Ab-negative group. In the RA patients, the PAD4 levels were not correlated with ACPAs. Neither PAD4 nor anti-PAD4 Abs were significantly correlated with the presence of SE alleles. The PAD4 levels were higher in RA than in SLE or HC. Anti-PAD4 Abs appeared specifically in patients with RA. Moreover, anti-PAD4 Abs were associated with ACPAs.
    Clinical Rheumatology 09/2015; DOI:10.1007/s10067-015-3082-z · 1.77 Impact Factor
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    ABSTRACT: Peptidylarginine deiminases (PADs) are posttranslational modification enzymes that convert protein arginine to citrulline residues in a calcium ion-dependent manner. Previously, we reported the abnormal accumulation of citrullinated proteins and the increase in the amount of PAD2 in hippocampi from Alzheimer's disease (AD) patients. Moreover, glial fibrillary acidic protein (GFAP), an astrocyte-specific marker protein, and vimentin were identified as citrullinated proteins by using two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry. To clarify the substrate specificity of PADs against GFAP, we prepared recombinant human (rh)PAD1, rhPAD2, rhPAD3, rhPAD4, and rhGFAP. After incubation of rhGFAP with rhPAD1, rhPAD2, rhPAD3, and rhPAD4, citrullinated (cit-)rhGFAP was detected by Western blotting. The citrullination of rhGFAP by rhPAD2 was unique, specific, and time dependent; additionally, rhPAD1 slightly citrullinated rhGFAP. We then generated eight anti-cit-rhGFAP monoclonal antibodies, CTGF-125, -128, -129, -1212, -1213, -1221, -122R, and -1224R, which reacted specifically with cit-rhGFAP. Two of those eight monoclonal antibodies, CTGF-122R and -1224R, reacted with both cit-rhGFAP and rhGFAP in Western blots. By using the CTGF-1221 antibody and a tandem mass spectrometer, we identified the two independent citrullination sites (R270Cit and R416Cit) of cit-rhGFAP. Immunohistochemical analysis with CTGF-1221 antibody revealed cit-GFAP staining in the hippocampus of AD brain, and the cit-GFAP-positive cells appeared to be astrocyte-like cells. These collective results strongly suggest that PAD2 is responsible for the citrullination of GFAP in the progression of AD and that the monoclonal antibody CTGF-1221, reacting with cit-GFAP at R270Cit and R416Cit, is useful for immunohistochemical investigation of AD brains. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
    Journal of Neuroscience Research 07/2015; 93(11). DOI:10.1002/jnr.23620 · 2.59 Impact Factor
  • N. Umeda · I. Matsumoto · Y. Kondo · H. Tsuboi · Y. Kagami · A. Ishigami · N. Maruyama · T. Sumida ·

    Annals of the Rheumatic Diseases 06/2015; 74(Suppl 2):935.1-935. DOI:10.1136/annrheumdis-2015-eular.2926 · 10.38 Impact Factor
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    ABSTRACT: Unlabelled: Recent studies on senescence marker protein-30 (SMP30) have shown that it has an important functional role in the aging process, but its precise participation in cellular works has not been fully determined. We hypothesize that SMP30 plays crucial roles in signaling processes by modulating the balance of protein tyrosine kinase (PTK)/protein tyrosine phosphatase (PTP) and in activating proinflammatory NF-κB. An experimental paradigm of gain and loss of SMP30 function was established using SMP30-overexpressed YPEN-1 cells (herein referred to as "SMP30(+) cells") and SMP30 (Y/-) knockout mouse kidneys. The resulting data show that SMP30 expression suppressed oxidative stress-induced PTK/PTP dysregulation and PP1/2A inactivation in SMP30(+) cells, leading to the suppression of NF-κB activation. In the kidneys of SMP30 (Y/-) mice, SMP30 deficiency was found to induce NF-κB activation via the upstream signaling of NIK/IKK and MAPKs and to upregulate downstream NF-κB-responsive gene expression. In this study, we also demonstrate for the first time that SMP30 deficiency induced PTK activity in SMP30 (Y/-) kidneys, thereby significantly increasing the tyrosine phosphorylation of a catalytic subunit of PP2A (PP2Ac-Tyr307). Based on these findings, we propose that SMP30 involves NF-κB regulation through the PTK/PTP balance and that the age-related decrease of SMP30 causes NF-κB activation, which contributes to an exacerbation of the inflammatory process during aging. Key messages: SMP30-deficient mice induced a shorter lifespan and redox changes. Overexpression of SMP30 prevented oxidative stress insults. The depletion of SMP30 increased redox-related PTK/PTP imbalance and PP1/PP2A inactivation. The depletion of SMP30 caused an elevation of NF-κB-responsive inflammatory markers. SMP30 may be a potent inhibitory protein against oxidative stress and chronic inflammation.
    Journal of Molecular Medicine 11/2014; 93(3). DOI:10.1007/s00109-014-1219-1 · 5.11 Impact Factor
  • Akihito Ishigami · Hirofumi Masutomi · Setsuko Handa · Naoki Maruyama ·
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    ABSTRACT: AimSenescence marker protein-30 (SMP30)/gluconolactonase (GNL) is an age-associated protein in that its presence decreases with aging. Here, we used immunohistochemical analysis to investigate the changes of SMP30/GNL in individual cells of the liver from progressively aged mice.Methods Male C57BL/6 strain mice at 1, 3, 6, 12, 24 and 30 months-of-age were the source of hepatic cells used to detect SMP30/GNL. Liver sections from these mice were subjected to immunohistochemical staining with anti-SMP30/GNL antibody. For immunofluorescent staining, primary cultured hepatocytes from mice at various ages were stained with SMP30/GNL and albumin.ResultsIn liver cells from mice of all ages, SMP30/GNL staining appeared in some but not all parenchymal cells, and localized in both the nuclei and cytoplasm. Moreover, SMP30/GNL-positive staining of parenchymal cells was present only around central vein areas, but not at sites of portal veins. Furthermore, the number of SMP30/GNL-positive cells increased as mice aged from 1 to 12 months, then decreased from the 12th to 24th month. Results were similar in primary cultured hepatocytes from mice of various ages.ConclusionsSMP30/GNL-positive cells localized mainly around the central veins in the livers of mice and decreased numerically with aging, although there was no age-related change in counts of albumin-positive cells. SMP30/GNL protein occupied the nuclei and cytoplasm. Therefore, nuclear SMP30/GNL protein might be a regulatory factor specific for genes whose expression governs transcription and the aging process. Geriatr Gerontol Int 2014; ●●: ●●–●●.
    Geriatrics & Gerontology International 11/2014; 15(6). DOI:10.1111/ggi.12347 · 2.19 Impact Factor
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    ABSTRACT: Individuals born with a low birth weight (LBW) have a higher risk of developing kidney dysfunction during their lifetime and sometimes exhibit focal segmental glomerulosclerosis (FSGS) lesions in their glomeruli. We herein try to obtain other pathological characteristics of LBW-related nephropathy. We retrospectively evaluated the renal pathology of four patients demonstrating FSGS with a history of LBW. Two mitochondrial cytopathy patients were also analyzed. DNA mutations were surveyed using a PCR-Luminex assay. In all four FSGS patients with a history of LBW, focal segmental glomerulosclerosis were detected. Interestingly, granular swollen epithelial cells (GSECs), which have previously been reported exclusively in patients with mitochondrial cytopathy, were also observed in the distal tubules and/or collecting ducts of all four patients with a history of low birth weight in this study. Electron microscopy revealed that these granular swollen epithelial cells included an increased number of enlarged mitochondria. Furthermore, cytochrome c oxidase subunit IV staining of patients with a history of low birth weight and patients with mitochondrial DNA mutations showed unbalanced expression patterns in glomeruli and a part of tubular cells. However, no mitochondrial gene mutations were detected in any of our four patients with low birth weight-related nephropathy. This is the first report to show the pathological similarities not only in glomeruli but also tubuli between nephropathy with a LBW history and nephropathy with mitochondrial cytopathy. Virtual Slides The virtual slide(s) for this article can be found here:
    Diagnostic Pathology 09/2014; 9(1):181. DOI:10.1186/s13000-014-0181-0 · 2.60 Impact Factor
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    ABSTRACT: Potato chips (PC) contain abundant amounts of the free-radical scavenger ascorbic acid (AA) due to the rapid dehydration of potato tubers (Solanum tuberosum) that occurs during frying. To evaluate the antioxidant activity of PC, we examined reactive oxygen species (ROS) levels in tissues from SMP30/GNL knockout (KO) mice that cannot synthesize AA and determined AA and ROS levels after the animals were fed 20 and 10% PC diets for 7 weeks. Compared with AA-sufficient mice, AA-depleted SMP30/GNL KO mice showed high ROS levels in tissues. SMP30/GNL KO mice fed a PC diet showed high AA and low ROS levels in brain, heart, lung, testis, soleus muscle, plantaris muscle, stomach, small intestine, large intestine, eyeball, and epididymal fat compared with AA-depleted mice. Our data suggest that PC intake increases AA levels and enhances ROS scavenging activity in tissues of SMP30/GNL-KO mice, which are a promising model for evaluating the antioxidant activity of foods.
    Journal of Agricultural and Food Chemistry 09/2014; 62(38). DOI:10.1021/jf502587j · 2.91 Impact Factor
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    ABSTRACT: Aims/IntroductionSenescence marker protein-30 (SMP30) is abundantly expressed in renal proximal tubule cells, but its expression decreases with age. Previous studies have shown that reduced SMP30 expression could contribute to aging-associated deterioration of cellular function and tissue injury. In the present study, we investigated the effects of SMP30 deficiency on the pathogenesis of diabetic nephropathy.Materials and Methods Diabetes was induced using streptozotocin in male SMP30 knockout mice (KO) and wild-type mice at 7 weeks-of-age. Vitamin C was added to the drinking water to prevent vitamin C deficiency in KO mice. The mice were killed 12 weeks after the induction of diabetes.ResultsUrinary biomarkers for proximal tubule damage were significantly increased in non-diabetic KO mice compared with wild-type mice. Furthermore, diabetes-induced tubular damage was significantly exacerbated by SMP30 deletion. Morphological analysis showed a link between cortical tubulointerstitial fibrosis area and the degree of tubular damage. However, SMP30 deletion did not affect mesangial expansion. Tubular injury was associated with accumulation of hypoxia-inducible factor-1α and increased hypoxia-inducible factor-1α targeted gene expression. SMP30 deletion initiated oxidative stress; however, it did not exacerbate the oxidative stress seen in diabetic mice. In contrast, tubular inflammation was associated with SMP30 deletion only in diabetic mice.Conclusions Based on this evidence, we concluded that SMP30 deficiency exacerbates proximal tubule injury in diabetic mice. Decreased SMP30 could contribute to the increased incidence of various chronic kidney diseases, including diabetic nephropathy, with age.
    07/2014; 6(1). DOI:10.1111/jdi.12252
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    ABSTRACT: Superoxide dismutase 1 (SOD1) is an antioxidant enzyme that converts superoxide anion radicals into hydrogen peroxide and molecular oxygen. The senescence marker protein-30 (SMP30) is a gluconolactonase that functions as an antioxidant protein in mammals due to its involvement in ascorbic acid (AA) biosynthesis. SMP30 also participates in Ca2+ efflux by activating the calmodulin-dependent Ca2+-pump. To reveal the role of oxidative stress in lipid metabolism defects occurring in non-alcoholic fatty liver disease pathogenesis, we generated SMP30/SOD1-double knockout (SMP30/SOD1-DKO) mice and investigated their survival curves, plasma and hepatic lipid profiles, amounts of hepatic oxidative stress, and hepatic protein levels expressed by genes related to lipid metabolism. While SMP30/SOD1-DKO pups had no growth retardation by 14 days of age, they did have low plasma and hepatic AA levels. Thereafter, 39% and 53% of male and female pups died by 15–24 and 89 days of age, respectively. Compared to wild type, SMP30-KO and SOD1-KO mice, by 14 days SMP30/SOD1-DKO mice exhibited: (1) higher plasma levels of triglyceride and aspartate aminotransferase; (2) severe accumulation of hepatic triglyceride and total cholesterol; (3) higher levels of superoxide anion radicals and thiobarbituric acid reactive substances in livers; and (4) decreased mRNA and protein levels of Apolipoprotein B (ApoB) in livers – ApoB is an essential component of VLDL secretion. These results suggest that high levels of oxidative stress due to concomitant deficiency of SMP30 and/or AA, and SOD1 cause abnormal plasma lipid metabolism, hepatic lipid accumulation and premature death resulting from impaired VLDL secretion.
    FEBS Open Bio 05/2014; 4. DOI:10.1016/j.fob.2014.05.003 · 1.52 Impact Factor
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    ABSTRACT: We sought to elucidate the effect of an ascorbic acid (AA) deficiency on gene expression, because the water soluble antioxidant AA is an important bioactive substance in vivo. We performed microarray analyses of the transcriptome in the liver from senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which are unable to synthesize AA in vivo. Our microarray analysis revealed that the AA deficiency increased gene expression related to the oxidation-reduction process, i.e., the nuclear factor, erythroid derived 2, like 2 (Nrf2) gene, which is a reactive oxygen species-sensitive transcriptional factor. Moreover, this AA deficiency increased the expression of genes for lipid metabolism including the cytochrome P450, family 7, subfamily a, polypeptide 1 (Cyp7a1), which is a late-limiting enzyme of the primary bile acid biosynthesis pathway. Although an AA deficiency increased the Cyp7a1 protein level, bile acid levels in the liver and gallbladder decreased. Since Cyp7a1 has a heme iron at the active site, AA must function as a reductant of the iron required for the continuous activation of Cyp7a1. This experimental evidence strongly supports a role for AA in the physiologic oxidation-reduction process and lipid metabolism including bile acid biosynthesis. General significance Although many effects of AA supplementation have been reported, no microarray analysis of AA deficiency in vivo is available. Results from using this unique model of AA deficiency, the SMP30/GNL-KO mouse, now provide new information about formerly unknown AA functions that will implement further study of AA in vivo.
    Biochimica et Biophysica Acta 04/2014; 1840(7). DOI:10.1016/j.bbagen.2014.03.019 · 4.66 Impact Factor
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    ABSTRACT: Background The spontaneous crescentic glomerulonephritis-forming/Kinjoh (SCG/Kj) mouse, a model of human crescentic glomerulonephritis (CrGN) and systemic vasculitis, is characterized by the production of MPO-ANCA and marked leukocytosis. This study was performed to identify the specific populations of leukocytes associated with CrGN and susceptibility loci for pathogenic leukocytosis.Methods420 female (C57BL/6 × SCG/Kj) F2 intercross mice were subjected to serial flow cytometry examination of the peripheral blood (PB). Kidney granulocytes and monocytes were histopathologically examined. Linkage analyses were done with 109 polymorphic microsatellite markers.ResultsCorrelation studies revealed that increase of the granulocytes, F4/80+ cells, CD3+CD4-CD8- T cells, and dendritic cells (DCs) in PB were significantly associated with glomerulonephritis, crescent formation and vasculitis. In kidney sections, F4/80low cells were observed in crescent, while F4/80high cells were around the Bowman's capsules and in the interstitium. Numbers of F4/80+ cells in crescents significantly correlated with F4/80+ cell numbers in PB, but not with numbers of F4/80+ cells in the interstitium. Genome-wide quantitative trait locus (QTL) mapping revealed three SCG/Kj-derived non-Fas QTLs for leukocytosis, two on chromosome 1 and one on chromosome 17. QTLs on chromosome 1 affected DCs, granulocytes and F4/80+ cells, but QTL on chromosome 17 affected DCs and granulocytes.Conclusion We found CrGN-associated leukocytes and susceptibility QTLs with their positional candidate genes. F4/80+ cells in crescents are considered as recruited inflammatory macrophages. The results provide information for leukocytes to be targeted and genetic elements in CrGN and vasculitis.
    Clinical & Experimental Immunology 03/2014; 177(1). DOI:10.1111/cei.12333 · 3.04 Impact Factor
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    ABSTRACT: Senescence marker protein-30 (SMP30) was first described as a physiologic entity that decreases in the rat liver and kidney with aging. Previously, we established that SMP30 is the lactone-hydrolyzing enzyme gluconolactonase (GNL), which is involved in ascorbic acid (AA) biosynthesis. In the present study, we found SMP30/GNL mRNA expressed in the mouse ovary. To ascertain the reason for ovarian SMP30/GNL expression, we examined mice during gestation. SMP30/GNL mRNA expression was evident at the start of gestation, increased for the next eight days then decreased rapidly. Moreover, L-gulono-γ-lactone oxidase (Gulo) mRNA, which catalyzes the last step of AA, was found in the ovaries of these mice. The variations of these genes' expression showed an inverse pattern to that of Cyp19a1 (aromatase) mRNA expression. Therefore, the SMP30/GNL and Gulo mRNA expression might be regulated by estrogen levels in the ovary. Since the presence of both SMP30/GNL and Gulo mRNAs could indicate that AA synthesis occurs in the ovary, we quantified AA levels in mouse ovaries during gestation. However, no correlation was found between changes of AA content and SMP30/GNL or Gulo mRNAs expression at this site. Moreover, we compared the changes of AA content during gestation between wild-type and SMP30/GNL knockout mice, which cannot synthesize AA, and found no significant differences between them. These results indicated that, although AA synthesis might occur in the ovaries, the amount of AA which is synthesized in ovaries must be quite low and insufficient to influence the AA content in ovary.
    Biological & Pharmaceutical Bulletin 12/2013; 36(12):2005-8. DOI:10.1248/bpb.b13-00309 · 1.83 Impact Factor
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    ABSTRACT: Senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice are incapable of synthesizing L-ascorbic acid (AA) in vivo. As AA is known to be a water-soluble anti-oxidant, we assessed protein oxidation levels in livers from SMP30/GNL KO mice maintained in an AA-insufficient condition. Livers were collected from male SMP30/GNL KO mice at the ages of 3, 6 and 12 months, and wild-type (WT) mice at the ages of 3, 6, 12 and 24 months. To assess protein oxidation, we measured the content of protein carbonyl, which is a major protein oxidation marker. AA levels were measured by 2,4-dinitrophenylhydrazine method using high-performance liquid chromatography. Livers of SMP30/GNL KO mice had just ∼5% as much AA as those of WT mice from 3 to 12 months-of-age. Protein carbonyl levels in livers from SMP30/GNL KO mice were a significant 1.8- to 2.3-fold higher than those from age-matched WT mice. To establish that the AA-insufficiency caused this difference, we added AA to some drinking water, and examined the effect on AA and protein carbonyl levels in livers from SMP30/GNL KO and WT mice. Livers from SMP30/GNL KO mice given extra AA had a significantly higher content than those from their deprived counterparts. Furthermore, protein carbonyl levels in livers from AA-supplemented SMP30/GNL KO mice were significantly lower than those from the SMP30/GNL KO mice without AA supplementation. However, added AA did not affect the protein carbonyl levels in WT mice. These results strongly suggest that AA plays an important role in preventing protein oxidation in vivo, thus enhancing overall health. Geriatr Gerontol Int 2013; ●●: ●●-●●.
    Geriatrics & Gerontology International 10/2013; 14(4). DOI:10.1111/ggi.12162 · 2.19 Impact Factor
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    ABSTRACT: Rationale: Vitamin C (VC) is a potent antioxidant and essential for collagen synthesis. Objectives: We investigated whether VC-treatment prevents and cures smoke-induced emphysema in senescence marker protein-30 knockout (SMP30-KO) mice, which cannot synthesize VC. Methods: Two smoke-exposure experiments using SMP30-KO were conducted. In the first one (a preventive study), four-month-old mice were received minimal VC (0.0375 g/L) [VC(L)] or physiologically sufficient VC (1.5 g/L) [VC(S)], then were exposed to cigarette smoke or smoke-free air for 2 months. Pulmonary evaluations followed when the mice were 6-months of age. The second, study began after the establishment of smoke-induced emphysema (a treatment study). These mice no longer underwent smoke exposure but received VC(S) or VC(L) treatment for 2 months. Morphometric analysis and measurements of oxidative stress, collagen synthesis, and vascular endothelial growth factor (VEGF) in the lungs were evaluated. Measurements and Main Results: Chronic smoke exposure caused emphysema [29.6% increases of mean linear intercepts (MLI) and 106.5% increases of destructive index (DI) compared with the air-only group] in 6-month-old SMP30-KO mice and this emphysema closely resembled human COPD. Furthermore, smoke-induced emphysema persisted in the VC(L) group after smoking cessation, whereas VC-treatment provided pulmonary restoration [18.5% decrease of MLI and 41.3% decrease of DI compared with VC(L) group]. VC-treatment diminished oxidative stress, increased collagen synthesis, and improved VEGF levels in the lungs. Conclusions: Our results suggest that VC not only prevents smoke-induced emphysema in SMP30-KO mice but also restores emphysematous lungs. Therefore, VC may provide a new therapeutic strategy for treating COPD in humans.
    American Journal of Respiratory Cell and Molecular Biology 09/2013; 50(2). DOI:10.1165/rcmb.2013-0121OC · 3.99 Impact Factor
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    ABSTRACT: BACKGROUNDAIMS: The senescence marker protein-30 (SMP30) is a 34 kDa protein originally identified in rat liver that shows decreased levels with age. Several functional studies using SMP30 knockout (Smp30(Y/-) ) mice established that SMP30 functions as an antioxidant and protects against apoptosis. To address the potential role of SMP30 in nonalcoholic fatty liver disease (NAFLD) pathogenesis, we established Smp30(Y/-) mice on a Lepr(db/db) background (Lepr(db/db)Smp30(Y/-) mice). RESEARCH DESIGNPRINCIPAL FINDINGS: Male Lepr(db/db)Smp30(Y/-) mice were fed a standard diet (340 kcal/100 g, fat 5.6%) for 16 weeks whereupon the lipid/lipoprotein profiles, hepatic expression of genes related to lipid metabolism and endoplasmic reticulum stress markers were analyzed by HPLC, quantitative RT-PCR and western blotting, respectively. Changes in the liver at a histological level were also investigated. The amount of SMP30 mRNA and protein in livers was decreased in Lepr(db/db)Smp30(Y/+) mice compared with Lepr(db/+)Smp30(Y/+) mice. Compared with Lepr(db/db)Smp30(Y/+) mice, 24 week old Lepr(db/db)Smp30(Y/-) mice showed: i) increased small dense LDL-cho and decreased HDL-cho levels; ii) fatty liver accompanied by numerous inflammatory cells and increased oxidative stress; iii) decreased mRNA expression of genes involved in fatty acid oxidation (PPARα) and lipoprotein uptake (LDLR and VLDLR) but increased CD36 levels; and iv) increased endoplasmic reticulum stress. Our data strongly suggest that SMP30 is closely associated with NAFLD pathogenesis, and might be a possible therapeutic target for NAFLD.
    PLoS ONE 06/2013; 8(6):e65698. DOI:10.1371/journal.pone.0065698 · 3.23 Impact Factor
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    ABSTRACT: Background Senescence-accelerated mice (SAM) are a series of mouse strains originally derived from unexpected crosses between AKR/J and unknown mice, from which phenotypically distinct senescence-prone (SAMP) and -resistant (SAMR) inbred strains were subsequently established. Although SAMP strains have been widely used for aging research focusing on their short life spans and various age-related phenotypes, such as immune dysfunction, osteoporosis, and brain atrophy, the responsible gene mutations have not yet been fully elucidated. Results To identify mutations specific to SAMP strains, we performed whole exome sequencing of 6 SAMP and 3 SAMR strains. This analysis revealed 32,019 to 38,925 single-nucleotide variants in the coding region of each SAM strain. We detected Ogg1 p.R304W and Mbd4 p.D129N deleterious mutations in all 6 of the SAMP strains but not in the SAMR or AKR/J strains. Moreover, we extracted 31 SAMP-specific novel deleterious mutations. In all SAMP strains except SAMP8, we detected a p.R473W missense mutation in the Ldb3 gene, which has been associated with myofibrillar myopathy. In 3 SAMP strains (SAMP3, SAMP10, and SAMP11), we identified a p.R167C missense mutation in the Prx gene, in which mutations causing hereditary motor and sensory neuropathy (Dejerine-Sottas syndrome) have been identified. In SAMP6 we detected a p.S540fs frame-shift mutation in the Il4ra gene, a mutation potentially causative of ulcerative colitis and osteoporosis. Conclusions Our data indicate that different combinations of mutations in disease-causing genes may be responsible for the various phenotypes of SAMP strains.
    BMC Genomics 04/2013; 14(1):248. DOI:10.1186/1471-2164-14-248 · 3.99 Impact Factor
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    ABSTRACT: Purpose: The effect of an AA deficiency on catecholamine biosynthesis in adult mice in vivo is unknown. Therefore, we quantified catecholamine and the expression of catecholamine synthetic enzymes in the adrenal glands of senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice placed in an AA-deficient state. Methods: At 30 days of age, mice were divided into the following 4 groups: AA (-) SMP30/GNL KO, AA (+) SMP30/GNL KO, AA (-) wild type (WT), and AA (+) WT. The AA (+) groups were given water containing 1.5 g/L AA, whereas the AA (-) groups received water without AA until the experiment ended. In addition, all mice were fed an AA-depleted diet. Catecholamine levels were measured by a liquid chromatographic method. Tyrosine hydroxylase, dopa decarboxylase, dopamine β-hydroxylase, and phenylethanolamine N-methyltransferase mRNA expression levels were measured with the quantitative real-time polymerase chain reaction (qPCR). Tyrosine hydroxylase and dopamine β-hydroxylase protein levels were quantified by Western blot analysis. Results: In the adrenals of AA (-) SMP30/GNL KO mice, noradrenaline and adrenaline levels decreased significantly compared to other three groups of mice, although there were no significant differences in dopamine β-hydroxylase or phenylethanolamine N-methyltransferase mRNA content. Moreover, there was no significant difference in their dopamine β-hydroxylase protein levels. On the other hand, AA depletion did not affect dopamine levels in adrenal glands of mice. Conclusion: An AA deficiency decreases the noradrenaline and adrenaline levels in adrenal glands of mice in vivo.
    European Journal of Nutrition 03/2013; 53(1). DOI:10.1007/s00394-013-0515-9 · 3.47 Impact Factor
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    ABSTRACT: Background: Despite the acknowledged importance of ascorbic acid (AA) in maintaining pregnancy and normal fetal development, its precise actions remain obscure. Therefore, we investigated the impact of maternal AA content on the growth of fetal mice during the gestation period using senescence marker protein-30/gluconolactonase (SMP30/GNL) knockout (KO) mice, which cannot synthesize AA in vivo. Methods: SMP30/GNL KO mice gave birth after a gestation period under conditions of absent, low, or normal AA intake. AA was measured using high-performance liquid chromatography and electrochemical detection. Whole-body sections were stained with hematoxylin and eosin, Elastica van Gieson, and Azan. Results: The mothers in the group absent AA intake failed to bear young because of incomplete fetal development. Offspring born under the low-AA condition generally died within a few days after birth. Morphological analysis revealed that the latter neonates of SMP30/GNL KO mothers whose intake of AA was low during gestation manifested abnormal cardiac dilation, congestion of the liver and lungs, incompletely expanded pulmonary alveoli, and impaired vertebral bodies. In contrast, a normal AA diet produced healthy progeny. Conclusion: A diet sufficiently replete with AA is essential during the gestational period for normal tissue development in the fetus and neonate.
    Pediatric Research 02/2013; 73(5). DOI:10.1038/pr.2013.22 · 2.31 Impact Factor
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    ABSTRACT: The senescence marker protein-30 (SMP30), which is also called regucalcin, exhibits gluconolactonase (GNL) activity. Biochemical and biological analyses revealed that SMP30/GNL catalyzes formation of the γ-lactone-ring of l-gulonate in the ascorbic acid biosynthesis pathway. The molecular basis of the γ-lactone formation, however, remains elusive due to the lack of structural information on SMP30/GNL in complex with its substrate. Here, we report the crystal structures of mouse SMP30/GNL and its complex with xylitol, a substrate analogue, and those with 1,5-anhydro-d-glucitol and d-glucose, product analogues. Comparison of the crystal structure of mouse SMP30/GNL with other related enzymes has revealed unique characteristics of mouse SMP30/GNL. First, the substrate-binding pocket of mouse SMP30/GNL is designed to specifically recognize monosaccharide molecules. The divalent metal ion in the active site and polar residues lining the substrate-binding cavity interact with hydroxyl groups of substrate/product analogues. Second, in mouse SMP30/GNL, a lid loop covering the substrate-binding cavity seems to hamper the binding of l-gulonate in an extended (or all-trans) conformation; l-gulonate seems to bind to the active site in a folded conformation. In contrast, the substrate-binding cavities of the other related enzymes are open to the solvent and do not have a cover. This structural feature of mouse SMP30/GNL seems to facilitate the γ-lactone-ring formation.
    PLoS ONE 01/2013; 8(1):e53706. DOI:10.1371/journal.pone.0053706 · 3.23 Impact Factor
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    ABSTRACT: Ascorbic acid (AA) functions as an electron donor and scavenges reactive oxygen species such as superoxide, singlet oxygen, and hydroxyl radicals in vitro. However, little is known about the effect of an AA deficiency on protein and lipid oxidation levels in the liver. Therefore, we measured the levels of protein carbonyl and thiobarbituric acid reactive substances (TBARS) in livers from senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice. These mice are deficient in AA, because they lack the SMP30/GNL gene, which is essential for the biosynthesis of AA in vivo. To track the effect of an AA deficiency, at 30 d of age, mice were divided into the following four groups: AA (-) SMP30/GNL KO, AA (+) SMP30/GNL KO, AA (-) wild type (WT), and AA (+) WT. The AA (+) groups were given water containing 1.5 g/L AA, whereas the AA (-) groups received water without AA for 57 d. All mice were fed an AA-free diet. Subsequently, protein carbonyl levels in livers from AA (-) SMP30/GNL KO mice were significantly higher than those from the other three groups; however, TBARS levels were not significantly different among the four groups. Therefore, AA must act as an anti-oxidant for proteins but might not directly protect lipid oxidation in the liver.
    Journal of Nutritional Science and Vitaminology 01/2013; 59(6):489-95. DOI:10.3177/jnsv.59.489 · 0.83 Impact Factor

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4k Citations
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  • 2007-2014
    • Tokyo Metropolitan Institute
      Edo, Tōkyō, Japan
  • 1987-2014
    • Tokyo Metropolitan Institute of Gerontology
      Edo, Tōkyō, Japan
  • 2008
    • Toho University
      • Department of Biochemistry
      Edo, Tōkyō, Japan
  • 2006
    • Niigata University
      • Division of Neurophysiology
      Niahi-niigata, Niigata, Japan
  • 2000-2001
    • Juntendo University
      • • Department of Internal Medicine
      • • Department of Medicine
      Edo, Tōkyō, Japan
  • 1995-1999
    • The Jikei University School of Medicine
      • Department of Internal Medicine
      Tokyo, Tokyo-to, Japan
  • 1997
    • Chiba University
      Tiba, Chiba, Japan
  • 1992
    • Okayama University
      Okayama, Okayama, Japan