Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Cardiorenal syndrome is a major cause of mortality in patients with chronic kidney disease (CKD). However, the involvement of detrimental humoral mediators in the pathogenesis of cardiorenal syndrome is still controversial. Trimethylamine-N-oxide (TMAO), a hepatic metabolic product of trimethylamine generated from dietary phosphatidylcholine or carnitine derived by the gut microbiota, has been linked directly with progression of cardiovascular disease and renal dysfunction. Thus, targeting TMAO may be a novel strategy for the prevention of cardiovascular disease and chronic kidney disease. METHODS: Linaclotide, a guanylate cyclase C agonist, was administered to adenine-induced renal failure (RF) mice and changes in renal function and levels of gut-derived uremic toxins, as well as the gut microbiota community, were analyzed using metabolomic and metagenomic methods to reveal its cardiorenal effect. RESULTS: Linaclotide decreased the plasma levels of TMAO at a clinically used low dose of 10 μg/kg in the adenine-induced RF mouse model. At a high concentration of 100 μg/kg, linaclotide clearly improved renal function and reduced the levels of various uremic toxins. A reduction in TMAO levels following linaclotide treatment was also observed in a choline-fed pro-atherosclerotic model. Linaclotide ameliorated renal inflammation and fibrosis and cardiac fibrosis, as well as decreased the expression of collagen I, transforming growth factor-β, galectin-3 (Gal-3) and ST2 genes. Plasma levels of Gal-3 and ST2 were also reduced. Because exposure of cardiomyocytes to TMAO increased fibronectin expression, these data suggest that linaclotide reduced the levels of TMAO and various uremic toxins and may result in not only renal, but also cardiac, fibrosis. F4/80-positive macrophages were abundant in small intestinal crypts in RF mice, and this increased expression was decreased by linaclotide. Reduced colonic claudin-1 levels were also restored by linaclotide, suggesting that linaclotide ameliorated the 'leaky gut' in RF mice. Metagenomic analysis revealed that the microbial order Clostridiales could be responsible for the change in TMAO levels. CONCLUSION: Linaclotide reduced TMAO and uremic toxin levels and could be a powerful tool for the prevention and control of the cardiorenal syndrome by modification of the gut-cardio-renal axis.

DOI： 10.1093/ndt/gfz126

PubMed

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Carboxyl-containing metabolites, such as bile acids and fatty acids, have many important functions and microbiota is involved in the production of them. In the previous study, we found that the chronic kidney disease (CKD) model mice raised under germ-free conditions provided more severe renal damage than the mice with commensal microbiota. However, the precise influence by the microbiome and carboxyl-containing metabolites to the renal functions is unknown. In this study, we aimed to develop a novel chemical isotope labeling-LC-MS/MS method using the 2-picolylamine and its isotopologue and applied the analysis of effects of microbiome and CKD pathophysiology. The developed semi-quantitative method provided the high accuracy not inferior to the absolute quantification. By comparing of four groups of mice, we found that both microbiota and renal function can alter the composition and level of these metabolites in both plasma and intestine. In particular, the intestinal level of indole-3-acetic acid, short-chain fatty acids and n-3 type of polyunsaturated fatty acid, which play important roles in the endothelial barrier function, were significantly lower in germ-free conditions mice with renal failure. Accordingly, it is suggested these metabolites might have a renoprotective effect on CKD by suppressing epithelial barrier disruption.

DOI： 10.1038/s41598-019-55600-1

PubMed

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Diabetic kidney disease is a major cause of renal failure that urgently necessitates a breakthrough in disease management. Here we show using untargeted metabolomics that levels of phenyl sulfate, a gut microbiota-derived metabolite, increase with the progression of diabetes in rats overexpressing human uremic toxin transporter SLCO4C1 in the kidney, and are decreased in rats with limited proteinuria. In experimental models of diabetes, phenyl sulfate administration induces albuminuria and podocyte damage. In a diabetic patient cohort, phenyl sulfate levels significantly correlate with basal and predicted 2-year progression of albuminuria in patients with microalbuminuria. Inhibition of tyrosine phenol-lyase, a bacterial enzyme responsible for the synthesis of phenol from dietary tyrosine before it is metabolized into phenyl sulfate in the liver, reduces albuminuria in diabetic mice. Together, our results suggest that phenyl sulfate contributes to albuminuria and could be used as a disease marker and future therapeutic target in diabetic kidney disease.

DOI： 10.1038/s41467-019-09735-4

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Journal of Physiology - Renal Physiology  

© 2018 the American Physiological Society. Mishima E, Fukuda S, Kanemitsu Y, Saigusa D, Mukawa C, Asaji K, Matsumoto Y, Tsukamoto H, Tachikawa T, Tsukimi T, Fukuda NN, Ho HJ, Kikuchi K, Suzuki C, Nanto F, Suzuki T, Ito S, Soga T, Tomioka Y, Abe T. Canagliflozin reduces plasma uremic toxins and alters the intestinal microbiota composition in a chronic kidney disease mouse model. Am J Physiol Renal Physiol 315: F824–F833, 2018. First published November 22, 2017; doi:10.1152/ajprenal.00314.2017.—Accumulation of uremic toxins, which exert deleterious effects in chronic kidney disease, is influenced by the intestinal environment; the microbiota contributes to the production of representative uremic toxins, including p-cresyl sulfate and indoxyl sulfate. Canagliflozin is a sodium-glucose cotransporter (SGLT) 2 inhibitor, and it also exerts a modest inhibitory effect on SGLT1. The inhibition of intestinal SGLT1 can influence the gastrointestinal environment. We examined the effect of canagliflozin on the accumulation of uremic toxins in chronic kidney disease using adenine-induced renal failure mice. Two-week canagliflozin (10 mg/kg po) treatment did not influence the impaired renal

DOI： 10.1152/ajprenal.00314.2017

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Toll-like receptor 4 (TLR4) is an indispensable immune receptor for lipopolysaccharide (LPS), a major component of the Gram-negative bacterial cell wall. Following LPS stimulation, TLR4 transmits the signal from the cell surface and becomes internalized in an endosome. However, the spatial regulation of TLR4 signaling is not fully understood. Here, we investigated the mechanisms of LPS-induced TLR4 internalization and clarified the roles of the extracellular LPS-binding molecules, LPS-binding protein (LBP), and glycerophosphatidylinositol-anchored protein (CD14). LPS stimulation of CD14-expressing cells induced TLR4 internalization in the presence of serum, and an inhibitory anti-LBP mAb blocked its internalization. Addition of LBP to serum-free cultures restored LPS-induced TLR4 internalization to comparable levels of serum. The secretory form of the CD14 (sCD14) induced internalization but required a much higher concentration than LBP. An inhibitory anti-sCD14 mAb was ineffective for serum-mediated internalization. LBP lacking the domain for LPS transfer to CD14 and a CD14 mutant with reduced LPS binding both attenuated TLR4 internalization. Accordingly, LBP is an essential serum molecule for TLR4 internalization, and its LPS transfer to membrane-anchored CD14 (mCD14) is a prerequisite. LBP induced the LPS-stimulated phosphorylation of TBK1, IKKϵ, and IRF3, leading to IFN-β expression. However, LPS-stimulated late activation of NF-κB or necroptosis were not affected. Collectively, our results indicate that LBP controls LPS-induced TLR4 internalization, which induces TLR adaptor molecule 1 (TRIF)-dependent activation of the TBK1-IKKϵ-IRF3-IFN-β pathway. In summary, we showed that LBP-mediated LPS transfer to mCD14 is required for serum-dependent TLR4 internalization and activation of the TRIF pathway.

DOI： 10.1074/jbc.M117.796631

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Alzheimer's disease (AD) is a progressive neurodegenerative disease and the most common form of elderly dementia in the world. At present, acetylcholine inhibitors, such as donepezil, galantamine and rivastigmine, are used for AD therapy, but the therapeutic efficacy is limited. We recently proposed T-type voltage-gated Ca2+ channels' (T-VGCCs) enhancer as a new therapeutic candidate for AD. In the current study, we confirmed the pharmacokinetics of SAK3 in the plasma and brain of mice using ultra performance liquid chromatography-tandem mass spectrometry. We also investigated the effects of SAK3 on the major symptoms of AD, such as cognitive dysfunction and amyloid beta (Aβ) accumulation, in AppNL-F knock-in (NL-F) mice, which have been established as an AD model. Chronic SAK3 (0.5 mg/kg/day) oral administration for 3 months from 9 months of age improved cognitive function and inhibited Aβ deposition in 12-month-old NL-F mice. Using microarray and real-time PCR analysis, we discovered serum- and glucocorticoid-induced protein kinase 1 (SGK1) as one of possible genes involved in the inhibition of Aβ deposition and improvement of cognitive function by SAK3. These results support the idea that T-VGCC enhancer, SAK3 could be a novel candidate for disease-modifying therapeutics for AD.

DOI： 10.1016/j.neuroscience.2018.02.031

PubMed

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Patients with chronic kidney disease (CKD) have increased blood levels of phenyl sulfate (PS), a circulating uremic toxin. In this study, we produced anti-PS monoclonal antibodies (mAbs) and characterized their cross-reactivity to structural PS analogs. To induce PS-specific mAbs, we synthesized 4-mercaptophenyl sulfate with a sulfhydryl group at the para-position of PS and conjugated it to carrier proteins via bifunctional linkers. Using these PS conjugates as immunogens and as antigens for enzyme-linked immunosorbent assay (ELISA) screening, we produced by a hybridoma method two novel mAbs (YK33.1 and YKS19.2) that react with PS conjugates independent of carrier and linker structures. Although all of the PS analogs tested, with the exception of indoxyl sulfate, were cross-reactive to both mAbs in phosphate buffered saline (PBS), PS specificity for YKS19.2 was enhanced in human plasma and serum. YKS19.2 mAb was cross-reactive only with o-cresyl sulfate, which is absent in human blood. PS sensitivity for YKS19.2 mAb increased to an IC50 of 10.4 µg/mL when 0.1% Tween 20 was added in a primary competitive reaction. To explore potential clinical applications, we determined concentrations of PS in serum samples from 19 CKD patients by inhibition ELISA using YKS19.2 mAb and compared them to those found using an LC-MS/MS method. A good correlation was observed between each value (R2=0.825). Therefore, the unique antigen specificity of YKS19.2 mAb could be useful for prescreening of patients with accumulated PS or for comprehensive analysis of uremic toxins that have a PS-like structure.

DOI： 10.1248/bpb.b17-00925

PubMed

researchmap

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Column choice is crucial to the development of liquid chromatography/tandem mass spectrometry (LC-MS/MS) methods because analyte selectivity is dependent on the nature of the stationary phase. Recently, mixed-mode chromatography, which employs a combination of two or more stationary phases and solvent systems, has emerged as an alternative to multiple, complementary, single-column systems. This report describes the development and validation of a novel analytical method based on LC-MS/MS employing a reversed-phase/cation-exchange/anion-exchange tri-modal column (Scherzo SS-C18; Imtakt) for the simultaneous quantification of various uremic toxins (UTx), including creatinine, 1-methyladenosine, trimethylamine-N-oxide, indoxyl sulfate, p-cresyl sulfate, phenyl sulfate and 4-ethylphenyl sulfate. Stable isotope-labeled compounds were prepared as internal standards (ISs) for each analyte. Mobile phase optimization and appropriate gradient conditions resulted in satisfactory retention and peak resolution that could not have been attained with a single stationary phase LC system. The essential validation parameters, including intra- and inter-assay precision and accuracy, were adequate. The validated method was applied to measure serum levels of the aforementioned compounds in 19 patients with chronic kidney disease. This is the first report detailing the simultaneous quantification of these analytes using stable isotopes as ISs. Our results suggest that Scherzo SS-C18 columns will be considered breakthrough tools in the development of analytical methods for compounds that are difficult to quantify simultaneously in traditional LC systems.

DOI： 10.1016/j.jchromb.2017.10.009

Web of Science

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Gut microbiota is involved in the metabolism of uremic solutes. However, the precise influence of microbiota to the retention of uremic solutes in CKD is obscure. To clarify this, we compared adenine-induced renal failure and control mice under germ-free or specific pathogen-free (SPF) conditions, examining the metabolite profiles of plasma, feces, and urine using a capillary electrophoresis time-of-flight mass spectrometry-based approach. Mice with renal failure under germ-free conditions demonstrated significant changes in plasma metabolites. Among 183 detected solutes, plasma levels of 11 solutes, including major uremic toxins, were significantly lower in germ-free mice than in SPF mice with renal failure. These 11 solutes were considered microbiota-derived uremic solutes and included indoxyl sulfate, p-cresyl sulfate, phenyl sulfate, cholate, hippurate, dimethylglycine, gamma-guanidinobutyrate, glutarate, 2-hydroxypentanoate, trimethylamine N-oxide, and phenaceturate. Metabolome profiling showed that these solutes were classified into three groups depending on their origins: completely derived from microbiota (indoxyl sulfate, p-cresyl sulfate), derived from both host and microbiota (dimethylglycine), and derived from both microbiota and dietary components (trimethylamine N-oxide). Additionally, germ-free renal failure conditions resulted in the disappearance of colonic short-chain fatty acids, decreased utilization of intestinal amino acids, and more severe renal damage compared with SPF mice with renal failure. Microbiota-derived short-chain fatty acids and efficient amino acid utilization may have a renoprotective effect, and loss of these factors may exacerbate renal damage in germ-free mice with renal failure. Thus, microbiota contributes substantially to the production of harmful uremic solutes, but conversely, growth without microbiota has harmful effects on CKD progression.

DOI： 10.1016/j.kint.2017.02.011

Web of Science

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/1873-3468.12837

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

Lipopolysaccharide (LPS)-induced activation of Toll-like receptor 4 (TLR4) elicits the innate immune response and can trigger septic shock if excessive. Two antibodies (HT4 and HT52) inhibit LPS-induced human TLR4 activation via novel LPS binding-independent mechanisms. The HT52 epitope resides on leucine-rich repeat 2 (LRR2) and is a feature of many inhibitory antibodies; antigen specificity of HT4 does not reside in LRR2. Here, we identified an HT4 epitope on LRR13 located close to the TLR4 dimerization interface that plays a role in NF kappa B activation. HT4 and HT52 mutually enhanced TLR4 inhibition. LRR13 is a novel inhibitory epitope and may be useful for developing anti-TLR4 antibodies. Combination therapy with LRR2 and LRR13 may effectively inhibit TLR4 activation.

DOI： 10.1002/1873-3468.12768

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Allergology  

The patient was a 6-year-old female with milk allergy and persistent asthma. She experienced anaphylactic reactions just after the inhalation of Inavir® (Laninamivir Octanoate Hydrate) to treat flu infection. A skin-prick test showed positive reactions for Inavir® inhaler powder and lactose used as an excipient but negative for Laninamivir. Same results were obtained in a drug-stimulated basophil activation test. The lactose excipient in Inavir® inhaler powder was supposed to contain milk proteins, which caused anaphylactic reactions. To test this possibility, we examined the contamination of allergic milk proteins in the lactose excipient and found the smear band by silver staining, which was identified as β-lactoglobulin (β-LG) by Western blotting using specific monoclonal antibody and patient's sera. The β-LG in Inavir® was supposed to be glycosylated with lactose because the molecular weight was slightly higher than β-LG standard reference as seen in mobility. In fact, the incubation with lactose in vitro tended to increase molecular weight. Following these results, we herein report that the trace amounts of β-LG contaminated in the lactose excipient of Inavir® could cause immediate allergic reactions. The risk that the lactose-containing dry powder inhalers cause allergic reactions for patients with cow's milk allergy need to be reminded. In particular, the use for flu patients should be paid careful attention because of increased airway hypersensitivity in those patients.

DOI： 10.15036/arerugi.65.200

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：OXFORD UNIV PRESS  

SLC10A4 belongs to the sodium bile acid cotransporter family, but has no transport activity for bile acids. We performed multiple amino acid alignments and examined the relationships between the SLC10 proteins. The extracellular N-terminus of SLC10A4 was predicted to be relatively longer at the amino acid level than those of SLC10A1, SLC10A2 and SLC10A6. We examined the relationship between the N-terminus and transport activity of SLC10A4. Rat Slc10a4 is predominantly expressed in rat cholinergic neurons; therefore, TE671 cells expressing the acetylcholine receptor and acetylcholinesterase were used. After thrombin treatment, western blotting and immunofluorescence staining demonstrated that the N-terminus of SLC10A4 might be cleaved. Substrates were added to the cells, and their uptake was quantified by liquid chromatography tandem mass spectrometry. Lithocholic acid (LCA) and taurocholic acid (TCA) uptake and cell death effects of LCA were increased by thrombin treatment. After RNA interference treatment for SLC10A4, bile acid uptake was also quantified. In consequence, increases in the LCA and TCA uptake did not occur. Therefore, SLC10A4 may have low activity but becomes activated by proteases, including thrombin, following cleavage. We have demonstrated that SLC10A4 appears to be a protease-activated transporter and transports bile acids.

DOI： 10.1093/jb/mvt031

Web of Science

PubMed

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Scientific Research Publishing, Inc.  

DOI： 10.4236/ajac.2011.23038

researchmap

Other Link： http://www.scirp.org/journal/doi.aspx?DOI=10.4236/ajac.2011.23038

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publisher：(一社)日本透析医学会  

researchmap

Authorship：Lead author   Language：Japanese  

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

researchmap

Language：Japanese   Publisher：(一社)日本内分泌学会  

researchmap

Language：Japanese   Publisher：(一社)日本内分泌学会  

researchmap

Language：Japanese   Publisher：(一社)日本医用マススペクトル学会  

J-GLOBAL

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

J-GLOBAL

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

researchmap

Language：Japanese   Publisher：(一社)日本小児腎臓病学会  

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

J-GLOBAL

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

J-GLOBAL

researchmap

Language：Japanese   Publisher：(一社)日本腎臓学会  

researchmap

Language：Japanese   Publisher：生命科学系学会合同年次大会運営事務局  

J-GLOBAL

researchmap

Language：Japanese   Publisher：生命科学系学会合同年次大会運営事務局  

researchmap

Language：Japanese   Publisher：(公社)日本薬学会  

researchmap

Language：Japanese   Publisher：(公社)日本薬学会  

J-GLOBAL

researchmap

Language：Japanese   Publisher：(公社)日本薬学会  

J-GLOBAL

researchmap

Language：Japanese   Publisher：(公社)日本薬学会  

J-GLOBAL

researchmap

Language：Japanese   Publisher：(公社)日本薬学会  

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese  

J-GLOBAL

researchmap

Language：Japanese   Publisher：(一社)日本アレルギー学会  

症例は,牛乳アレルギーおよび気管支喘息既往歴を有する6歳女児.インフルエンザB型に罹患し,ラニナミビルオクタン酸エステル水和物吸入粉末剤(イナビル)を使用後にアナフィラキシーを起こした.プリックテスト並びに薬剤刺激好塩基球活性化試験を実施したところ,イナビルと添加剤の乳糖水和物に陽性を示し,ラニナミビルオクタン酸エステル水和物は陰性を示した.本症例では,添加剤の乳糖に夾雑する乳タンパク質がアレルゲンとなった可能性が考えられ,その同定を試みた.ウェスタンブロット(WB)により,添加剤の乳糖水和物中からβ-ラクトグロブリン(β-LG)が検出され,その分子量およびin vitro実験の結果から糖鎖付加体であると推定した.さらに患者血清を用いたWBの結果から,本症例のアレルゲンが,糖鎖付加されたβ-LGである可能性が高いと判断した.本研究は,吸入粉末製剤の添加剤乳糖が乳アレルギーを起こす危険性を示す結果となった.本症例のようなインフルエンザ患者は,気道過敏性が亢進しているため特に注意が必要である.(著者抄録)

researchmap

Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2016&ichushi_jid=J00009&link_issn=&doc_id=20160525320008&doc_link_id=130005152388&url=http%3A%2F%2Fci.nii.ac.jp%2Fnaid%2F130005152388&type=CiNii&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00003_1.gif

Language：Japanese   Publisher：(株)医薬ジャーナル社  

入院時に患者が持ち込む持参薬は、入院前は服用が継続できており、また、担当医の専門領域外の薬剤であることも多いため、その副作用が新規プロブレムとして抽出され難い場合がある。特に、病態変化や薬剤による腎・肝障害は、薬物動態に影響を及ぼすため、注意を要する。このような場面では、病棟薬剤師が担当医へ積極的に情報提供し、処方提案を行うことが重要となる。今回、抗がん剤治療施行後に、持参薬の薬物動態の変動が原因で副作用の発現が疑われた2例に対して、薬剤師の介入後、症状の改善が認められた例を紹介する。これらの介入を通じて、病棟薬剤師による持参薬を含めた薬学的管理が、リスクマネジメントの観点から重要であることが再認識された。(著者抄録)

researchmap

Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2014&ichushi_jid=J00065&link_issn=&doc_id=20140613120010&doc_link_id=10.20837%2F1201406119&url=https%3A%2F%2Fdoi.org%2F10.20837%2F1201406119&type=%88%E3%8F%91.jp_%83I%81%5B%83%8B%83A%83N%83Z%83X&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

Language：Japanese   Publisher：(公社)日本薬学会  

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap