研究者詳細 - 伊藤　美佳子

論文 - 伊藤　美佳子

分割表示 111 件中 1 - 20 件目／全件表示 >>

Extremely low-frequency electromagnetic field (ELF-EMF) enhances mitochondrial energy production in NARP cybrids. 査読有り Open Access

Ito M, Huang Z, Nomura K, Teranishi M, Zhao F, Mino H, Yoneda M, Tanaka M, Ohno K

Scientific reports 15 巻 ( 1 ) 頁： 24369 2025年7月

記述言語：英語出版者・発行元：Scientific Reports

A mutation (m.8993T > G) in MT-ATP6 in mitochondrial DNA (mtDNA) causes the neuropathy, ataxia, retinitis pigmentosa (NARP) syndrome by impairing mitochondrial energy production. Extremely low-frequency electromagnetic field (ELF-EMF) suppresses mitochondrial oxidative phosphorylation (OXPHOS) Complex II and induces mitohormetic activation of mitochondrial OXPHOS activities. We examined the effects of ELF-EMF on normal cybrids carrying 100% wild-type mtDNA (2SA cybrids) and NARP cybrids carrying 40% wild-type and 60% mutant mtDNA (NARP3-2 cybrids). We found that ELF-EMF had no effect on the copy number of mtDNA either in 2SA or NARP3-2 cybrids, or the ratio of wild-type-to-mutant mtDNA in NARP3-2 cybrids. Instead, ELF-EMF increased the transcription of mtDNA and the transcription ratio of wild-type-to-mutant mtDNA in NARP3-2 cybrids. In addition, ELF-EMF increased the expression of mitochondrial OXPHOS proteins and the mitochondrial OXPHOS Complex V activity in NARP3-2 cybrids. ELF-EMF upregulated fission-promoting phosphorylation of DRP1, as well as the expression of fusion-promoting MFN1 and MFN2, in NARP3-2 cybrids. ELF-EMF also increased ATP production estimated by oxygen consumption rates (OCR) and by a biochemical assay in NARP3-2 cybrids. Hormetic activation of mitochondria by ELF-EMF is likely to be effective to ameliorate defective mitochondrial energy production in NARP and other mitochondrial diseases.

DOI： 10.1038/s41598-025-10536-7

Review of 40 genes causing congenital myasthenic syndromes. 査読有り Open Access

Ohno K, Ito M, Ohkawara B

Journal of human genetics 2025年6月

記述言語：英語出版者・発行元：Journal of Human Genetics

Congenital myasthenic syndromes (CMS) are a heterogeneous group of disorders characterized by compromised neuromuscular signal transmission due to pathogenic germline variants in genes expressed at the neuromuscular junction (NMJ). A total of 40 genes have been reported in CMS (AGRN, ALG14, ALG2, CHAT, CHD8, CHRNA1, CHRNB1, CHRND, CHRNE, CHRNG, COL13A1, COLQ, DES, DOK7, DPAGT1, GFPT1, GMPPB, LAMA5, LAMB2, LRP4, MACF1, MUSK, MYO9A, PLEC, PREPL, PTPN11, PURA, RAPSN, RPH3A, SCN4A, SLC18A3, SLC25A1, SLC5A7, SNAP25, SYT2, TEFM, TOR1AIP1, UNC13A, UNC50 and VAMP1). The 40 genes are putatively classified into 13 subtypes by pathomechanical, clinical, and therapeutic features. A unique feature shared by recently identified genes is that CMS is concomitantly recognized in other mostly severer diseases. For example, four recently identified genes exhibit the following phenotypes: PURA-CMS, developmental delay; TEFM-CMS, mitochondrial disease; PTPN11-CMS, Noonan syndrome/Leopard syndrome; and DES-CMS, desmin myopathy. Conversely, these diseases are not always associated with CMS, although genetic and/or environmental factors that determine the involvement of the NMJ remain to be identified. In this review, particular emphasis will be placed on five recently identified genes (MACF1, TEFM, PTPN11, DES and UNC50).

DOI： 10.1038/s10038-025-01355-9

Butyrate-producing bacteria in pregnancy maintenance: mitigating dysbiosis-induced preterm birth. 査読有り Open Access

Uchida A, Imai K, Miki R, Hamaguchi T, Nishiwaki H, Ito M, Ueyama J, Hattori S, Tano S, Fuma K, Matsuo S, Ushida T, Ohno K, Kajiyama H, Kotani T

Journal of translational medicine 23 巻 ( 1 ) 頁： 533 2025年5月

記述言語：英語出版者・発行元：Journal of Translational Medicine

Background: Preterm birth (PTB) is a major contributor to neonatal morbidity, mortality, and long-term health complications. Despite advances in perinatal care, PTB rates remain high, and its multifactorial etiology is not fully understood. Increasing evidence suggests that maternal gut microbiota plays a critical role in pregnancy maintenance, potentially through modulation of immune responses. However, the underlying causal mechanisms remain unclear. We hypothesized that dysbiosis disrupts immune tolerance and promotes PTB, and that butyrate (short-chain fatty acid produced by specific gut bacteria) may counteract this effect by enhancing regulatory T cell (Treg)-mediated immune regulation. Methods: We established a dysbiosis-induced PTB mouse model using vancomycin treatment combined with subclinical immune activation via anti-CD3ε antibody. Pregnant mice were fed either a standard or butyrate-enriched diet. Outcomes included gestational length, PTB incidence, live pup rates, and Treg cell levels assessed by flow cytometry. Parallelly, 16S rRNA gene sequencing was performed on fecal samples from 32 pregnant women to compare gut microbial composition between spontaneous PTB and term birth groups. Multivariate logistic regression and correlation analyses were conducted to assess associations with gestational outcomes. Results: Vancomycin-induced dysbiosis in mice significantly reduced Treg cell populations and increased PTB rates (43.3% in dysbiosis vs. 0% in controls; p < 0.05), while butyrate supplementation reduced PTB incidence (p = 0.03), prolonged gestation (p = 0.01), and restored Treg counts (p < 0.001). In human samples, significant reductions in Lachnospiraceae and Ruminococcaceae, representative butyrate-producing bacteria, were seen in PTB cases. Their combined abundance was independently associated with sPTB risk (p = 0.019) and positively correlated with gestational age (r = 0.59, p < 0.001). Conclusions: Our findings demonstrate that maternal dysbiosis increases PTB risk via impaired immune tolerance, and that butyrate supplementation effectively reverses this effect in vivo. Human data support the translational relevance of butyrate-producing microbiota in pregnancy maintenance. These results highlight butyrate as a promising target for dietary interventions aimed at reducing PTB incidence by restoring immune homeostasis. Trial registration Not applicable.

DOI： 10.1186/s12967-025-06534-y

Desulfovibrio falkowii sp. nov., Porphyromonas miyakawae sp. nov., Mediterraneibacter flintii sp. nov. and Owariibacterium komagatae gen. nov., sp. nov., isolated from human faeces. 査読有り

Hamaguchi T, Ohara M, Hisatomi A, Sekiguchi K, Takeda JI, Ueyama J, Ito M, Nishiwaki H, Ogi T, Hirayama M, Ohkuma M, Sakamoto M, Ohno K

International journal of systematic and evolutionary microbiology 75 巻 ( 1 ) 2025年1月

記述言語：英語出版者・発行元：International Journal of Systematic and Evolutionary Microbiology

Small, obligately anaerobic strains 13CB8CT, 13CB11CT, 13CB18CT and 13GAM1GT were isolated from a faecal sample in a patient with Parkinson’s disease with a history of duodenal resection. After conducting a comprehensive polyphasic taxonomic analysis including genomic analysis, we propose the establishment of one new genus and four new species. The novel bacteria are Desulfovibrio falkowii sp. nov. (type strain JCM 36128T = DSM 116810T), Porphyromonas miyakawae sp. nov. (type strain JCM 36129T = DSM 116947T), Mediterraneibacter flintii sp. nov. (type strain JCM 36130T = DSM 116866T) and Owariibacterium komaga-tae gen. nov. sp. nov. (type strain JCM 36131T = DSM 116982T), respectively.

DOI： 10.1099/ijsem.0.006636

Gut Microbiome Composition Changes During Insomnia Treatment with Lemborexant. 査読有り Open Access

Miyata S, Iwamoto K, Ito M, Okada I, Matsuyama N, Fujimoto A, Kogo Y, Nishiwaki H, Ueyama J, Ohno K, Ozaki N

Nature and science of sleep 17 巻頁： 1709 - 1726 2025年

Soy protein β-conglycinin ameliorates pressure overload-induced heart failure by increasing short-chain fatty acid (SCFA)-producing gut microbiota and intestinal SCFAs 査読有り Open Access

Furukawa, N; Kobayashi, M; Ito, M; Matsui, H; Ohashi, K; Murohara, T; Takeda, JI; Ueyama, J; Hirayama, M; Ohno, K

CLINICAL NUTRITION 43 巻 ( 12 ) 頁： 124 - 137 2024年12月

記述言語：英語出版者・発行元：Clinical Nutrition

Background and aims: Soybeans and their ingredients have antioxidant and anti-inflammatory effects on cardiovascular diseases. β-Conglycinin (β-CG), a major constituent of soy proteins, is protective against obesity, hypertension, and chronic kidney disease, but its effects on heart failure remain to be elucidated. We tested the effects of β-CG on left ventricular (LV) remodeling in pressure overload-induced heart failure. Methods: A transverse aortic constriction (TAC)-induced pressure overload was applied to the heart in 7-week-old C57BL6 male mice that were treated with β-CG, GlcNAc, or sodium propionate. Gut microbiota was analyzed by 16S rRNA sequencing. Fecal short-chain fatty acids (SCFAs) were quantified by GC-MS. The effects of oral antibiotics were examined in β-CG-fed mice. Results: β-CG ameliorated impaired cardiac contractions, cardiac hypertrophy, and myocardial fibrosis in TAC-operated mice. As β-CG is a highly glycosylated protein, we examined the effects of GlcNAc. GlcNAc had similar but less efficient effects on LV remodeling compared to β-CG. β-CG increased three major SCFA-producing intestinal bacteria, as well as fecal concentrations of SCFAs, in sham- and TAC-operated mice. Oral administration of antibiotics nullified the effects of β-CG in TAC-operated mice by markedly reducing SCFA-producing intestinal bacteria and fecal SCFAs. In contrast, oral administration of sodium propionate, one of SCFAs, ameliorated LV remodeling in TAC-operated mice to a similar extent as β-CG. Conclusions: β-CG was protective against TAC-induced LV remodeling, which was likely to be mediated by increased SCFA-producing gut microbiota and increased intestinal SCFAs. Modified β-CG and/or derivatives arising from β-CG are expected to be developed as prophylactic and/or therapeutic agents to ameliorate devastating symptoms in heart failure.

DOI： 10.1016/j.clnu.2024.09.045

A class of chemical compounds enhances clustering of muscle nicotinic acetylcholine receptor in cultured myogenic cells 査読有り国際誌 Open Access

Miyairi, Y; Ohkawara, B; Sato, A; Sawada, R; Ishii, H; Tomita, H; Inoue, T; Nakashima, H; Ito, M; Masuda, A; Hosono, Y; Imagama, S; Ohno, K

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 731 巻頁： 150400 - 150400 2024年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Biochemical and Biophysical Research Communications

Neuromuscular signal transmission is affected in various diseases including myasthenia gravis, congenital myasthenic syndromes, and sarcopenia. We used an ATF2-luciferase system to monitor the phosphorylation of MuSK in HEK293 cells introduced with MUSK and LRP4 cDNAs to find novel chemical compounds that enhanced agrin-mediated acetylcholine receptor (AChR) clustering. Four compounds with similar chemical structures carrying benzene rings and heterocyclic rings increased the luciferase activities 8- to 30-folds, and two of them showed continuously graded dose dependence. The effects were higher than that of disulfiram, a clinically available aldehyde dehydrogenase inhibitor, which we identified to be the most competent preapproved drug to enhance ATF2-luciferase activity in the same assay system. In C2C12 myotubes, all the compounds increased the area, intensity, length, and number of AChR clusters. Three of the four compounds increased the phosphorylation of MuSK, but not of Dok7, JNK. ERK, or p38. Monitoring cell toxicity using the neurite elongation of NSC34 neuronal cells as a surrogate marker showed that all the compounds had no effects on the neurite elongation up to 1 μM. Extensive docking simulation and binding structure prediction of the four compounds with all available human proteins using AutoDock Vina and DiffDock showed that the four compounds were unlikely to directly bind to MuSK or Dok7, and the exact target remained unknown. The identified compounds are expected to serve as a seed to develop a novel therapeutic agent to treat defective NMJ signal transmission.

DOI： 10.1016/j.bbrc.2024.150400

Extremely Low-Frequency Electromagnetic Field (ELF-EMF) Increases Mitochondrial Electron Transport Chain Activities and Ameliorates Depressive Behaviors in Mice 査読有り Open Access

Teranishi, M; Ito, M; Huang, ZZ; Nishiyama, Y; Masuda, A; Mino, H; Tachibana, M; Inada, T; Ohno, K

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 25 巻 ( 20 ) 頁： 11315 - 11315 2024年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Molecular Sciences

Compromised mitochondrial electron transport chain (ETC) activities are associated with depression in humans and rodents. However, the effects of the enhancement of mitochondrial ETC activities on depression remain elusive. We recently reported that an extremely low-frequency electromagnetic field (ELF-EMF) of as low as 10 μT induced hormetic activation of mitochondrial ETC complexes in human/mouse cultured cells and mouse livers. Chronic social defeat stress (CSDS) for 10 consecutive days caused behavioral defects mimicking depression in mice, and using an ELF-EMF for two to six weeks ameliorated them. CSDS variably decreased the mitochondrial ETC proteins in the prefrontal cortex (PFC) in 10 days, which were increased by an ELF-EMF in six weeks. CSDS had no effect on the mitochondrial oxygen consumption rate in the PFC in 10 days, but using an ELF-EMF for six weeks enhanced it. CSDS inactivated SOD2 by enhancing its acetylation and increased lipid peroxidation in the PFC. In contrast, the ELF-EMF activated the Sirt3-FoxO3a-SOD2 pathway and suppressed lipid peroxidation. Furthermore, CSDS increased markers for mitophagy, which was suppressed by the ELF-EMF in six weeks. The ELF-EMF exerted beneficial hormetic effects on mitochondrial energy production, mitochondrial antioxidation, and mitochondrial dynamics in a mouse model of depression. We envisage that an ELF-EMF is a promising therapeutic option for depression.

DOI： 10.3390/ijms252011315

Muscle-specific lack of Gfpt1 triggers ER stress to alleviate misfolded protein accumulation 査読有り国際誌 Open Access

Zhang, RC; Farshadyeganeh, P; Ohkawara, B; Nakajima, K; Takeda, JI; Ito, M; Zhang, SC; Miyasaka, Y; Ohno, T; Mori-Yoshimura, M; Masuda, A; Ohno, K

DISEASE MODELS & MECHANISMS 17 巻 ( 8 ) 2024年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Dmm Disease Models and Mechanisms

Pathogenic variants in GFPT1, encoding a key enzyme to synthesize UDP-N-acetylglucosamine (UDP-GlcNAc), cause congenital myasthenic syndrome (CMS). We made a knock-in (KI) mouse model carrying a frameshift variant in Gfpt1 exon 9, simulating that found in a patient with CMS. As Gfpt1 exon 9 is exclusively expressed in striated muscles, Gfpt1-KI mice were deficient for Gfpt1 only in skeletal muscles. In Gfpt1-KI mice, (1) UDP-HexNAc, CMP-NeuAc and protein O-GlcNAcylation were reduced in skeletal muscles; (2) aged Gfpt1-KI mice showed poor exercise performance and abnormal neuromuscular junction structures; and (3) markers of the unfolded protein response (UPR) were elevated in skeletal muscles. Denervation-mediated enhancement of endoplasmic reticulum (ER) stress in Gfpt1-KI mice facilitated protein folding, ubiquitin-proteasome degradation and apoptosis, whereas autophagy was not induced and protein aggregates were markedly increased. Lack of autophagy was accounted for by enhanced degradation of FoxO1 by increased Xbp1-s/u proteins. Similarly, in Gfpt1-silenced C2C12 myotubes, ER stress exacerbated protein aggregates and activated apoptosis, but autophagy was attenuated. In both skeletal muscles in Gfpt1-KI mice and Gfpt1-silenced C2C12 myotubes, maladaptive UPR failed to eliminate protein aggregates and provoked apoptosis.

DOI： 10.1242/dmm.050768

Calcitriol ameliorates motor deficits and prolongs survival of Chrne-deficient mouse, a model for congenital myasthenic syndrome, by inducing Rspo2. 査読有り国際誌

Ohkawara B, Tomita H, Inoue T, Zhang S, Kanbara S, Koshimizu H, Miyasaka Y, Takeda JI, Nishiwaki H, Nakashima H, Ito M, Masuda A, Ishiguro N, Ogi T, Ohno T, Imagama S, Ohno K

Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics 21 巻 ( 2 ) 頁： e00318 2024年1月

Splicing regulation of GFPT1 muscle-specific isoform and its roles in glucose metabolisms and neuromuscular junction 査読有り Open Access

Farshadyeganeh, P; Nazim, M; Zhang, RC; Ohkawara, B; Nakajima, K; Rahman, MA; Nasrin, F; Ito, M; Takeda, JI; Ohe, K; Miyasaka, Y; Ohno, T; Masuda, A; Ohno, K

ISCIENCE 26 巻 ( 10 ) 頁： 107746 2023年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：iScience

Glutamine:fructose-6-phosphate transaminase 1 (GFPT1) is the rate-limiting enzyme of the hexosamine biosynthetic pathway (HBP). A 54-bp exon 9 of GFPT1 is specifically included in skeletal and cardiac muscles to generate a long isoform of GFPT1 (GFPT1-L). We showed that SRSF1 and Rbfox1/2 cooperatively enhance, and hnRNP H/F suppresses, the inclusion of human GFPT1 exon 9 by modulating recruitment of U1 snRNP. Knockout (KO) of GFPT1-L in skeletal muscle markedly increased the amounts of GFPT1 and UDP-HexNAc, which subsequently suppressed the glycolytic pathway. Aged KO mice showed impaired insulin-mediated glucose uptake, as well as muscle weakness and fatigue likely due to abnormal formation and maintenance of the neuromuscular junction. Taken together, GFPT1-L is likely to be acquired in evolution in mammalian striated muscles to attenuate the HBP for efficient glycolytic energy production, insulin-mediated glucose uptake, and the formation and maintenance of the neuromuscular junction.

DOI： 10.1016/j.isci.2023.107746

Extremely low-frequency electromagnetic field induces acetylation of heat shock proteins and enhances protein folding 査読有り国際誌 Open Access

Huang, ZZ; Ito, M; Zhang, SC; Toda, T; Takeda, JI; Ogi, T; Ohno, K

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 264 巻頁： 115482 - 115482 2023年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Ecotoxicology and Environmental Safety

The pervasive weak electromagnetic fields (EMF) inundate the industrialized society, but the biological effects of EMF as weak as 10 µT have been scarcely analyzed. Heat shock proteins (HSPs) are molecular chaperones that mediate a sequential stress response. HSP70 and HSP90 provide cells under undesirable situations with either assisting covalent folding of proteins or degrading improperly folded proteins in an ATP-dependent manner. Here we examined the effect of extremely low-frequency (ELF)-EMF on AML12 and HEK293 cells. Although the protein expression levels of HSP70 and HSP90 were reduced after an exposure to ELF-EMF for 3 h, acetylations of HSP70 and HSP90 were increased, which was followed by an enhanced binding affinities of HSP70 and HSP90 for HSP70/HSP90-organizing protein (HOP/STIP1). After 3 h exposure to ELF-EMF, the amount of mitochondria was reduced but the ATP level and the maximal mitochondrial oxygen consumption were increased, which was followed by the reduced protein aggregates and the increased cell viability. Thus, ELF-EMF exposure for 3 h activated acetylation of HSPs to enhance protein folding, which was returned to the basal level at 12 h. The proteostatic effects of ELF-EMF will be able to be applied to treat pathological states in humans.

DOI： 10.1016/j.ecoenv.2023.115482

<i>Fusobacterium</i> infection facilitates the development of endometriosis through the phenotypic transition of endometrial fibroblasts 査読有り国際誌

Muraoka, A; Suzuki, M; Hamaguchi, T; Watanabe, S; Iijima, K; Murofushi, Y; Shinjo, K; Osuka, S; Hariyama, Y; Ito, M; Ohno, K; Kiyono, T; Kyo, S; Iwase, A; Kikkawa, F; Kajiyama, H; Kondo, Y

SCIENCE TRANSLATIONAL MEDICINE 15 巻 ( 700 ) 頁： eadd1531 2023年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Science Translational Medicine

Retrograde menstruation is a widely accepted cause of endometriosis. However, not all women who experience retrograde menstruation develop endometriosis, and the mechanisms underlying these observations are not yet understood. Here, we demonstrated a pathogenic role of Fusobacterium in the formation of ovarian endometriosis. In a cohort of women, 64% of patients with endometriosis but <10% of controls were found to have Fusobacterium infiltration in the endometrium. Immunohistochemical and biochemical analyses revealed that activated transforming growth factor–β (TGF-β) signaling resulting from Fusobacterium infection of endometrial cells led to the transition from quiescent fibroblasts to transgelin (TAGLN)–positive myofibroblasts, which gained the ability to proliferate, adhere, and migrate in vitro. Fusobacterium inoculation in a syngeneic mouse model of endometriosis resulted in a marked increase in TAGLN-positive myofibroblasts and increased number and weight of endometriotic lesions. Furthermore, antibiotic treatment largely prevented establishment of endometriosis and reduced the number and weight of established endometriotic lesions in the mouse model. Our data support a mechanism for the pathogenesis of endometriosis via Fusobacterium infection and suggest that eradication of this bacterium could be an approach to treat endometriosis.

DOI： 10.1126/scitranslmed.add1531

Interactions between muscle glucose homeostasis and neuromuscular signal transduction - Lessons learned from lack of a muscle-specific long isoform of GFPT1 査読有り

Farshadyeganeh, P; Nazim, M; Ohkawara, B; Masuda, A; Ito, M; Takeda, J; Ohe, K; Ohno, K

EUROPEAN JOURNAL OF HUMAN GENETICS 31 巻頁： 31 - 31 2023年5月

Interactions between muscle glucose homeostasis and neuromuscular signal transduction - Lessons learned from lack of a muscle-specific long isoform of GFPT1 査読有り

Farshadyeganeh, P., Nazim, M., Ohkawara, B., Masuda, A., Ito, M., Takeda, J., Ohe, K., Ohno, K.

EUROPEAN JOURNAL OF HUMAN GENETICS 31 巻頁： 31 - 31 2023年5月

A mutation in DOK7 in congenital myasthenic syndrome forms aggresome in cultured cells, and reduces DOK7 expression and MuSK phosphorylation in patient-derived iPS cells 査読有り Open Access

Zhang, SC; Ohkawara, B; Ito, M; Huang, ZZ; Zhao, F; Nakata, T; Takeuchi, T; Sakurai, H; Komaki, H; Kamon, M; Araki, T; Ohno, K

HUMAN MOLECULAR GENETICS 32 巻 ( 9 ) 頁： 1511 - 1523 2023年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Human Molecular Genetics

At the neuromuscular junction, the downstream of tyrosine kinase 7 (DOK7) enhances the phosphorylation of muscle-specific kinase (MuSK) and induces clustering of acetylcholine receptors (AChRs). We identified a patient with congenital myasthenic syndrome (CMS) with two heteroallelic mutations in DOK7, c.653-1G>C in intron 5 and c.190G>A predicting p.G64R in the pleckstrin homology domain. iPS cells established from the patient (CMS-iPSCs) showed that c.653-1G>C caused in-frame skipping of exon 6 (120 bp) and frame-shifting activation of a cryptic splice site deleting seven nucleotides in exon 6. p.G64R reduced the expression of DOK7 to 10% of wild-type DOK7, and markedly compromised AChR clustering in transfected C2C12 myotubes. p.G64R-DOK7 made insoluble aggresomes at the juxtanuclear region in transfected C2C12 myoblasts and COS7 cells, which were co-localized with molecules in the autophagosome system. A protease inhibitor MG132 reduced the soluble fraction of p.G64R-DOK7 and enhanced the aggresome formation of p.G64RDOK7. To match the differentiation levels between patient-derived and control induced pluripotent stem cells (iPSCs), we corrected c.190G>A (p.G64R) by CRISPR/Cas9 to make isogenic iPSCs while retaining c.653-1G>C (CMS-iPSCs<sup>Cas9</sup>). Myogenically differentiated CMS-iPSCs showed juxtanuclear aggregates of DOK7, reduced expression of endogenous DOK7 and reduced phosphorylation of endogenous MuSK. Another mutation, p.T77M, also made aggresome to a less extent compared with p.G64R in transfected COS7 cells. These results suggest that p.G64R-DOK7 makes aggresomes in cultured cells and is likely to compromise MuSK phosphorylation for AChR clustering.

DOI： 10.1093/hmg/ddac306

Neural Isoforms of Agrin Are Generated by Reduced PTBP1-RNA Interaction Network Spanning the Neuron-Specific Splicing Regions in <i>AGRN</i> 査読有り国際誌 Open Access

Bushra, S; Lin, YN; Joudaki, A; Ito, M; Ohkawara, B; Ohno, K; Masuda, A

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 24 巻 ( 8 ) 2023年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Molecular Sciences

Agrin is a heparan sulfate proteoglycan essential for the clustering of acetylcholine receptors at the neuromuscular junction. Neuron−specific isoforms of agrin are generated by alternative inclusion of three exons, called Y, Z8, and Z11 exons, although their processing mechanisms remain elusive. We found, by inspection of splicing cis−elements into the human AGRN gene, that binding sites for polypyrimidine tract binding protein 1 (PTBP1) were extensively enriched around Y and Z exons. PTBP1−silencing enhanced the coordinated inclusion of Y and Z exons in human SH−SY5Y neuronal cells, even though three constitutive exons are flanked by these alternative exons. Deletion analysis using minigenes identified five PTBP1−binding sites with remarkable splicing repression activities around Y and Z exons. Furthermore, artificial tethering experiments indicated that binding of a single PTBP1 molecule to any of these sites represses nearby Y or Z exons as well as the other distal exons. The RRM4 domain of PTBP1, which is required for looping out a target RNA segment, was likely to play a crucial role in the repression. Neuronal differentiation downregulates PTBP1 expression and promotes the coordinated inclusion of Y and Z exons. We propose that the reduction in the PTPB1−RNA network spanning these alternative exons is essential for the generation of the neuron−specific agrin isoforms.

DOI： 10.3390/ijms24087420

Effects of Pesticide Intake on Gut Microbiota and Metabolites in Healthy Adults 査読有り国際誌 Open Access

Ueyama, J; Hayashi, M; Hirayama, M; Nishiwaki, H; Ito, M; Saito, I; Tsuboi, Y; Isobe, T; Ohno, K

INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 20 巻 ( 1 ) 2023年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Environmental Research and Public Health

Animal experiments have indicated that pesticides may affect gut microbiota, which is responsible for the production of short-chain fatty acids (SCFAs) and polyamines. Here, we present a preliminary observation of the relationship between pesticide exposure and fecal SCFAs and polyamines in Japanese adults. In total, 38 healthy adults aged 69 ± 10 years (mean ± SD) were recruited and subjected to stool and spot urine tests. Urinary dialkylphosphates (DAP), 3-phenoxybenzoic acid, and glyphosate were assayed as pesticide exposure markers of organophosphorus insecticide (OP), a pyrethroid insecticide, and glyphosate, respectively. Significant negative correlations (p < 0.05, Spearman’s rank correlation coefficient) were found between urinary DAP, fecal acetate (r = −0.345), and lactate (r = −0.391). Multiple regression analyses revealed that urinary DAP was a significant explanatory variable of fecal acetate concentration (p < 0.001, β = −24.0, SE = 4.9, t = −4.9) with some vegetable intake (adjusted R-square = 0.751). These findings suggest that OP exposure is independently associated with lower fecal acetate levels, which may contribute to human health in middle-aged and older adult groups. Given that the human gut environment has long-term effects on the host, studies on wide-range age groups, including children, are necessary.

DOI： 10.3390/ijerph20010213

Gut microbiota in dementia with Lewy bodies 査読有り国際誌 Open Access

Nishiwaki, H; Ueyama, J; Kashihara, K; Ito, M; Hamaguchi, T; Maeda, T; Tsuboi, Y; Katsuno, M; Hirayama, M; Ohno, K

NPJ PARKINSONS DISEASE 8 巻 ( 1 ) 頁： 169 - 169 2022年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Npj Parkinson S Disease

Gut microbiota and fecal bile acids were analyzed in 278 patients with α-synucleinopathies, which were comprised of 28 patients with dementia with Lewy bodies (DLB), 224 patients with Parkinson’s disease (PD), and 26 patients with idiopathic rapid eye movement sleep behavior disorder (iRBD). Similarly to PD, short-chain fatty acids-producing genera were decreased in DLB. Additionally, Ruminococcus torques and Collinsella were increased in DLB, which were not changed in PD. Random forest models to differentiate DLB and PD showed that high Ruminococcus torques and high Collinsella, which presumably increase intestinal permeability, as well as low Bifidobacterium, which are also observed in Alzheimer’s disease, were predictive of DLB. As Ruminococcus torques and Collinsella are also major secondary bile acids-producing bacteria, we quantified fecal bile acids and found that the production of ursodeoxycholic acid (UDCA) was high in DLB. Increased UDCA in DLB may mitigate neuroinflammation at the substantia nigra, whereas neuroinflammation may not be critical at the neocortex. Theraeutic intervention to increase Bifidobacteirum and its metabolites may retard the development and progression of DLB.

DOI： 10.1038/s41531-022-00428-2

Examination of Abnormal Alpha-synuclein Aggregates in the Enteric Neural Plexus in Patients with Ulcerative Colitis 査読有り国際誌 Open Access

Gibo, N; Hamaguchi, T; Miki, Y; Yamamura, T; Nakaguro, M; Ito, M; Nakamura, M; Kawashima, H; Hirayama, M; Hirooka, Y; Wakabayashi, K; Ohno, K

JOURNAL OF GASTROINTESTINAL AND LIVER DISEASES 31 巻 ( 3 ) 頁： 290 - 300 2022年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Gastrointestinal and Liver Diseases

Background & Aims: Parkinson’s disease (PD) is the second most neurodegenerative disease after Alzheimer’s disease. Accumulating knowledge points to the notion that abnormal aggregation of alpha-synuclein (αSyn) starts in the gut and ascends to the substantia nigra via the vagus nerve in about a half of PD patients. Epidemiological studies revealed that ulcerative colitis (UC) increased the a risk for PD 1.3 to 1.8-folds. However, it remains unknown whether αSyn is abnormally aggregated in the enteric neurons in UC patients. Methods: We first inspected and optimized the immunostaining protocols with an anti-phosphorylated αSyn antibody, pSyn#64, using the brain and the gut of eight autopsied cases (five with PD and three without PD). Then, we examined abnormal αSyn aggregation in the enteric neurons in 23 and 18 colectomized patients with and without UC, respectively. Five or more sections were stained for αSyn in each of 87 and 25 paraffin-embedded blocks in patients with and without UC, respectively. Results: Ten different protocols of epitope exposure appropriately stained aggregated αSyn in the brain, but only a complete lack of epitope exposure stained aggregated αSyn in the colon with low background. Abnormal αSyn aggregates, which was confirmed by co-localization of p62, in the enteric neurons were detected in a single patient with UC but in no patient without UC. Conclusions: Omission of epitope exposure enabled us to immunostain aggregated αSyn in the colon by pSyn#64 with low nonspecific staining, but the number of 23 UC patients was not high enough to discern whether abnormal αSyn aggregation in the colonic neural plexus was increased in UC or not.

DOI： 10.15403/jgld-4313

　前のページ - 次のページ　

1
2
3
4
5
6