Publications by authors named "Noritaka Saeki"

12 Publications

  • Page 1 of 1

Myofiber androgen receptor increases muscle strength mediated by a skeletal muscle splicing variant of Mylk4.

iScience 2021 Apr 13;24(4):102303. Epub 2021 Mar 13.

Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Shitsukawa, Toon, Ehime 791-0295, Japan.

Androgens have a robust effect on skeletal muscles to increase muscle mass and strength. The molecular mechanism of androgen/androgen receptor (AR) action on muscle strength is still not well known, especially for the regulation of sarcomeric genes. In this study, we generated androgen-induced hypertrophic model mice, myofiber-specific androgen receptor knockout (cARKO) mice supplemented with dihydrotestosterone (DHT). DHT treatment increased grip strength in control mice but not in cARKO mice. Transcriptome analysis by RNA-seq, using skeletal muscles obtained from control and cARKO mice treated with or without DHT, identified a fast-type muscle-specific novel splicing variant of as a target of AR in skeletal muscles. knockout mice exhibited decreased maximum isometric torque of plantar flexion and passive stiffness of myofibers due to reduced phosphorylation of Myomesin 1 protein. This study suggests that androgen-induced skeletal muscle strength is mediated with Mylk4 and Myomesin 1 axis.
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http://dx.doi.org/10.1016/j.isci.2021.102303DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8041868PMC
April 2021

DNA maintenance methylation enzyme Dnmt1 in satellite cells is essential for muscle regeneration.

Biochem Biophys Res Commun 2021 01 10;534:79-85. Epub 2020 Dec 10.

Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Shitsukawa, Toon Ehime, 791-0295, Japan; Department of Pathophysiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon Ehime, 791-0295, Japan; Division of Laboratory Animal Research, Advanced Research Support Center, Ehime University, Shitsukawa, Toon Ehime, 791-0295, Japan. Electronic address:

Epigenetic transcriptional regulation is essential for the differentiation of various types of cells, including skeletal muscle cells. DNA methyltransferase 1 (Dnmt1) is responsible for maintenance of DNA methylation patterns via cell division. Here, we investigated the relationship between Dnmt1 and skeletal muscle regeneration. We found that Dnmt1 is upregulated in muscles during regeneration. To assess the role of Dnmt1 in satellite cells during regeneration, we performed conditional knockout (cKO) of Dnmt1 specifically in skeletal muscle satellite cells using Pax7 mice and Dnmt1 flox mice. Muscle weight and the cross-sectional area after injury were significantly lower in Dnmt1 cKO mice than in control mice. RNA sequencing analysis revealed upregulation of genes involved in cell adhesion and apoptosis in satellite cells from cKO mice. Moreover, satellite cells cultured from cKO mice exhibited a reduced number of cells. These results suggest that Dnmt1 is an essential factor for muscle regeneration and is involved in positive regulation of satellite cell number.
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http://dx.doi.org/10.1016/j.bbrc.2020.11.116DOI Listing
January 2021

Reprogramming of synovial macrophage metabolism by synovial fibroblasts under inflammatory conditions.

Cell Commun Signal 2020 11 30;18(1):188. Epub 2020 Nov 30.

Division of Laboratory Animal Research, Advanced Research Support Center, Ehime University, Shitsukawa, Toon, Ehime, 791-0295, Japan.

Background: Macrophages adapt to microenvironments, and change metabolic status and functions to regulate inflammation and/or maintain homeostasis. In joint cavities, synovial macrophages (SM) and synovial fibroblasts (SF) maintain homeostasis. However, under inflammatory conditions such as rheumatoid arthritis (RA), crosstalk between SM and SF remains largely unclear.

Methods: Immunofluorescent staining was performed to identify localization of SM and SF in synovium of collagen antibody induced arthritis (CAIA) model mice and normal mice. Murine arthritis tissue-derived SM (ADSM), arthritis tissue-derived SF (ADSF) and normal tissue-derived SF (NDSF) were isolated and the purity of isolated cells was examined by RT-qPCR and flow cytometry analysis. RNA-seq was conducted to reveal gene expression profile in ADSM, NDSF and ADSF. Cellular metabolic status and expression levels of metabolic genes and inflammatory genes were analyzed in ADSM treated with ADSM-conditioned medium (ADSM-CM), NDSF-CM and ADSF-CM.

Results: SM and SF were dispersed in murine hyperplastic synovium. Isolations of ADSM, NDSF and ADSF to analyze the crosstalk were successful with high purity. From gene expression profiles by RNA-seq, we focused on secretory factors in ADSF-CM, which can affect metabolism and inflammatory activity of ADSM. ADSM exposed to ADSF-CM showed significantly upregulated glycolysis and mitochondrial respiration as well as glucose and glutamine uptake relative to ADSM exposed to ADSM-CM and NDSF-CM. Furthermore, mRNA expression levels of metabolic genes, such as Slc2a1, Slc1a5, CD36, Pfkfb1, Pfkfb3 and Irg1, were significantly upregulated in ADSM treated with ADSF-CM. Inflammation marker genes, including Nos2, Tnf, Il-1b and CD86, and the anti-inflammatory marker gene, Il-10, were also substantially upregulated by ADSF-CM. On the other hand, NDSF-CM did not affect metabolism and gene expression in ADSM.

Conclusions: These findings suggest that crosstalk between SM and SF under inflammatory conditions can induce metabolic reprogramming and extend SM viability that together can contribute to chronic inflammation in RA. Video Abstract.
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http://dx.doi.org/10.1186/s12964-020-00678-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7708128PMC
November 2020

The E3 ubiquitin ligase MIB2 enhances inflammation by degrading the deubiquitinating enzyme CYLD.

J Biol Chem 2019 09 31;294(38):14135-14148. Epub 2019 Jul 31.

Division of Cell-Free Sciences, Proteo-Science Center (PROS), 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan

The tumor suppressor CYLD is a deubiquitinating enzyme that suppresses polyubiquitin-dependent signaling pathways, including the proinflammatory and cell growth-promoting NF-κB pathway. Missense mutations in the gene are present in individuals with syndromes such as multiple familial trichoepithelioma (MFT), but the pathogenic roles of these mutations remain unclear. Recent studies have shown that CYLD interacts with a RING finger domain protein, mind bomb homologue 2 (MIB2), in the regulation of NOTCH signaling. However, whether MIB2 is an E3 ubiquitin ligase that acts on CYLD is unknown. Here, using the cell-free-based AlphaScreen and pulldown assays to detect protein-protein interactions, along with immunofluorescence assays and murine knockout cells and animals, we demonstrate that MIB2 promotes proteasomal degradation of CYLD and enhances NF-κB signaling. Of note, arthritic inflammation was suppressed in -deficient mice. We further observed that the ankyrin repeat in MIB2 interacts with the third CAP domain in CYLD and that MIB2 catalyzes Lys-48-linked polyubiquitination of CYLD at Lys-338 and Lys-530. MIB2-dependent CYLD degradation activated NF-κB signaling via tumor necrosis factor alpha (TNFα) stimulation and the linear ubiquitination assembly complex (LUBAC). -knockout mice had reduced serum interleukin-6 (IL-6) and exhibited suppressed inflammatory responses in the K/BxN serum-transfer arthritis model. Interestingly, MIB2 significantly enhanced the degradation of a CYLD variant identified in an individual with MFT, although the molecular pathogenesis of the disease was not clarified here. Together, these results suggest that MIB2 enhances NF-κB signaling in inflammation by promoting the ubiquitin-dependent degradation of CYLD.
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http://dx.doi.org/10.1074/jbc.RA119.010119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6755803PMC
September 2019

GPRC5A facilitates cell proliferation through cell cycle regulation and correlates with bone metastasis in prostate cancer.

Int J Cancer 2020 03 22;146(5):1369-1382. Epub 2019 Jul 22.

Department of Pathophysiology, Ehime University Graduate School of Medicine, Toon, Japan.

The prognosis of patients with progressive prostate cancers that are hormone refractory and/or have bone metastasis is poor. Multiple therapeutic targets to improve prostate cancer patient survival have been investigated, including orphan GPCRs. In our study, we identified G Protein-Coupled Receptor Class C Group 5 Member A (GPRC5A) as a candidate therapeutic molecule using integrative gene expression analyses of registered data sets for prostate cancer cell lines. Kaplan-Meier analysis of TCGA data sets revealed that patients who have high GPRC5A expression had significantly shorter overall survival. PC3 prostate cancer cells with CRISPR/Cas9-mediated GPRC5A knockout exhibited significantly reduced cell proliferation both in vitro and in vivo. RNA-seq revealed that GPRC5A KO PC3 cells had dysregulated expression of cell cycle-related genes, leading to cell cycle arrest at the G2/M phase. Furthermore, the registered gene expression profile data set showed that the expression level of GPRC5A in original lesions of prostate cancer patients with bone metastasis was higher than that without bone metastasis. In fact, GPRC5A KO PC3 cells failed to establish bone metastasis in xenograft mice models. In addition, our clinical study revealed that GPRC5A expression levels in prostate cancer patient samples were significantly correlated with bone metastasis as well as the patient's Gleason score (GS). Combined assessment with the immunoreactivity of GPRC5A and GS displayed higher specificity for predicting the occurrence of bone metastasis. Together, our findings indicate that GPRC5A can be a possible therapeutic target and prognostic marker molecule for progressive prostate cancer.
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http://dx.doi.org/10.1002/ijc.32554DOI Listing
March 2020

Zscan10 suppresses osteoclast differentiation by regulating expression of Haptoglobin.

Bone 2019 05 13;122:93-100. Epub 2019 Feb 13.

Department of Pathophysiology, Graduate School of Medicine, Ehime University, Toon, Ehime, Japan; Division of Laboratory Animal Research, Advanced Research Support Center, Ehime University, Toon, Ehime, Japan; Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan. Electronic address:

Zinc finger and SCAN domain containing 10 (Zscan10) was identified as a novel transcription factor that is involved in osteoclast differentiation in our previous report. However, the biological functions of Zscan10 are not fully understood except its roles in the maintenance of genome stability and pluripotency of embryonic stem cells. Therefore, the purpose of this study was to clarify the function of Zscan10 in somatic cells, especially during osteoclast differentiation. First, Zscan10 KO RAW264 (KO) cells were established by genome editing using CRISPR/Cas9 and single cell sorting. Then, control (Ctrl) and KO cells were differentiated into osteoclasts by RANKL stimulation. We observed that TRAP activity and the expression levels of differentiation marker genes, such as Nfatc1, were significantly increased and the expression of inhibitory factors, such as Irf8, was decreased in KO cells compared to Ctrl cells. These results suggest that Zscan10 might regulate transcription of the genes that negatively control osteoclastogenesis. To understand gene expression profiles controlled by Zscan10, RNA-seq was performed and stringent analyses identified the haptoglobin gene (Hp) as a possible target of Zscan10. In addition, ChIP against Zscan10 revealed that Zscan10 could interact with its binding motif located near the Hp gene locus as well as the transcription start site of Hp, suggesting that Zscan10 can directly regulate transcription of Hp. Finally, to examine the effects of Hp on osteoclastogenesis, KO cells were treated with recombinant Hp (rHp). rHp treatment suppressed TRAP activity of KO cells without affecting cell viability. Furthermore, it has been reported that Hp KO mice exhibit decreased bone mass and increased osteoclast number. Importantly, hemolytic disease patients exhibited decreased serum level of Hp as well as low bone mineral density. Taken together, this study suggests that Zscan10 negatively regulates osteoclast differentiation through transcription of Hp.
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http://dx.doi.org/10.1016/j.bone.2019.02.011DOI Listing
May 2019

Uhrf1 is indispensable for normal limb growth by regulating chondrocyte differentiation through specific gene expression.

Development 2018 01 8;145(1). Epub 2018 Jan 8.

Division of Integrative Pathophysiology, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan

Transcriptional regulation can be tightly orchestrated by epigenetic regulators. Among these, ubiquitin-like with PHD and RING finger domains 1 (Uhrf1) is reported to have diverse epigenetic functions, including regulation of DNA methylation. However, the physiological functions of Uhrf1 in skeletal tissues remain unclear. Here, we show that limb mesenchymal cell-specific Uhrf1 conditional knockout mice ( ) exhibit remarkably shortened long bones that have morphological deformities due to dysregulated chondrocyte differentiation and proliferation. RNA-seq performed on primary cultured chondrocytes obtained from mice showed abnormal chondrocyte differentiation. In addition, integrative analyses using RNA-seq and MBD-seq revealed that Uhrf1 deficiency decreased genome-wide DNA methylation and increased gene expression through reduced DNA methylation in the promoter regions of 28 genes, including , which is reported to be an IL1-related gene and to affect chondrocyte differentiation. knockdown in cKO chondrocytes can normalize abnormal expression of genes involved in chondrocyte differentiation, such as These results indicate that Uhrf1 governs cell type-specific transcriptional regulation by controlling the genome-wide DNA methylation status and regulating consequent cell differentiation and skeletal maturation.
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http://dx.doi.org/10.1242/dev.157412DOI Listing
January 2018

EphA receptors and ephrin-A ligands are upregulated by monocytic differentiation/maturation and promote cell adhesion and protrusion formation in HL60 monocytes.

BMC Cell Biol 2017 08 29;18(1):28. Epub 2017 Aug 29.

Laboratory of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano, Osaka, 598-8531, Japan.

Background: Eph signaling is known to induce contrasting cell behaviors such as promoting and inhibiting cell adhesion/spreading by altering F-actin organization and influencing integrin activities. We have previously demonstrated that EphA2 stimulation by ephrin-A1 promotes cell adhesion through interaction with integrins and integrin ligands in two monocyte/macrophage cell lines. Although mature mononuclear leukocytes express several members of the EphA/ephrin-A subclass, their expression has not been examined in monocytes undergoing during differentiation and maturation.

Results: Using RT-PCR, we have shown that EphA2, ephrin-A1, and ephrin-A2 expression was upregulated in murine bone marrow mononuclear cells during monocyte maturation. Moreover, EphA2 and EphA4 expression was induced, and ephrin-A4 expression was upregulated, in a human promyelocytic leukemia cell line, HL60, along with monocyte differentiation toward the classical CD14CD16 monocyte subset. Using RT-PCR and flow cytometry, we have also shown that expression levels of αL, αM, αX, and β2 integrin subunits were upregulated in HL60 cells along with monocyte differentiation while those of α4, α5, α6, and β1 subunits were unchanged. Using a cell attachment stripe assay, we have shown that stimulation by EphA as well as ephrin-A, likely promoted adhesion to an integrin ligand-coated surface in HL60 monocytes. Moreover, EphA and ephrin-A stimulation likely promoted the formation of protrusions in HL60 monocytes.

Conclusions: Notably, this study is the first analysis of EphA/ephrin-A expression during monocytic differentiation/maturation and of ephrin-A stimulation affecting monocyte adhesion to an integrin ligand-coated surface. Thus, we propose that monocyte adhesion via integrin activation and the formation of protrusions is likely promoted by stimulation of EphA as well as of ephrin-A.
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http://dx.doi.org/10.1186/s12860-017-0144-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5576293PMC
August 2017

Truncated EphA2 likely potentiates cell adhesion via integrins as well as infiltration and/or lodgment of a monocyte/macrophage cell line in the red pulp and marginal zone of the mouse spleen, where ephrin-A1 is prominently expressed in the vasculature.

Histochem Cell Biol 2017 Mar 24;147(3):317-339. Epub 2016 Sep 24.

Laboratory of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano, Osaka, 598-8531, Japan.

We previously established a J774.1 monocyte/macrophage subline expressing a truncated EphA2 construct lacking the kinase domain. We demonstrated that following ephrin-A1 stimulation, endogenous EphA2 promotes cell adhesion through interaction with integrins and integrin ligands such as ICAM1 and that truncated EphA2 potentiates the adhesion and becomes associated with the integrin/integrin ligand complex. Based on these findings, we hypothesized that the EphA/ephrin-A system, particularly EphA2/ephrin-A1, regulates transendothelial migration/tissue infiltration of monocytes/macrophages, because ephrin-A1 is widely recognized to be upregulated in inflammatory vasculatures. To evaluate whether this hypothesis is applicable in the spleen, we screened for EphA2/ephrin-A1 expression and reexamined the cellular properties of the J774.1 subline. We found that ephrin-A1 was expressed in the vasculature of the marginal zone and the red pulp and that its expression was upregulated in response to phagocyte depletion; further, CD115, F4/80, and CXCR4 were expressed in J774.1 cells, which serve as a usable substitute for monocytes/macrophages. Moreover, following ephrin-A1 stimulation, truncated EphA2 did not detectably interfere with the phosphorylation of endogenous EphA2, and it potentiated cell adhesion possibly through modulation of integrin avidity. Accordingly, by intravenously injecting mice with equal numbers of J774.1 and the subline cells labeled with distinct fluorochromes, we determined that truncated EphA2 markedly potentiated preferential cell infiltration into the red pulp and the marginal zone. Thus, modulation of EphA2 signaling might contribute to effective transplantation of tissue-specific resident macrophages and/or monocytes.
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http://dx.doi.org/10.1007/s00418-016-1494-8DOI Listing
March 2017

EphA2 promotes cell adhesion and spreading of monocyte and monocyte/macrophage cell lines on integrin ligand-coated surfaces.

Cell Adh Migr 2015 ;9(6):469-82

a Laboratory of Veterinary Anatomy; Graduate School of Life and Environmental Sciences; Osaka Prefecture University ; Izumisano , Osaka , Japan.

Eph signaling, which arises following stimulation by ephrins, is known to induce opposite cell behaviors such as promoting and inhibiting cell adhesion as well as promoting cell-cell adhesion and repulsion by altering the organization of the actin cytoskeleton and influencing the adhesion activities of integrins. However, crosstalk between Eph/ephrin with integrin signaling has not been fully elucidated in leukocytes, including monocytes and their related cells. Using a cell attachment stripe assay, we have shown that, following stimulation with ephrin-A1, kinase-independent EphA2 promoted cell spreading/elongation as well as adhesion to integrin ligand-coated surfaces in cultured U937 (monocyte) and J774.1 (monocyte/macrophage) cells as well as sublines of these cells expressing dominant negative EphA2 that lacks most of the intracellular region. Moreover, a pull-down assay showed that dominant negative EphA2 is recruited to the β2 integrin/ICAM1 and β2 integrin/VCAM1 molecular complexes in the subline cells following stimulation with ephrin-A1-Fc. Notably, this study is the first comprehensive analysis of the effects of EphA2 receptors on integrin-mediated cell adhesion in monocytic cells. Based on these findings we propose that EphA2 promotes cell adhesion by an unknown signaling pathway that largely depends on the extracellular region of EphA2 and the activation of outside-in integrin signaling.
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http://dx.doi.org/10.1080/19336918.2015.1107693DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4955956PMC
September 2016

Aberrant EphB/ephrin-B expression in experimental gastric lesions and tumor cells.

World J Gastroenterol 2015 Jan;21(2):453-64

Shintaro Uchiyama, Noritaka Saeki, Kazushige Ogawa, Department of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 598-8531, Japan.

Aim: To determine whether the expression profiles of EphB receptor and ephrin-B ligand can be used as markers for dysplastic/oncogenic transformation in gastric mucosa.

Methods: The protein expression and localization of EphB and ephrin-B in normal, ulcerated regenerating, and dysplastic gastric mucosa were examined in a rat experimental model by immunolabeling, and mRNA expression was assessed in four human gastric carcinoma cell lines by reverse transcription-polymerase chain reaction.

Results: Ephrin-B- and EphB-expressing regions were divided along the pit-gland axis in normal gastric units. EphB2 was transiently upregulated in the experimental ulcer, and its expression domain extended to gastric pits and/or the luminal surface where ephrin-B-expressing pit cells reside. EphB2, B3, and B4 and ephrin-B1 were coexpressed in the experimental gastric dysplasia, and more than one ligand-receptor pair was highly expressed in each of the gastric carcinoma cell lines.

Conclusion: Robust and stable coexpression of EphB and ephrin-B is a feature common to experimentally induced gastric dysplasia and human gastric carcinoma cell lines as compared to normal gastric and ulcerated regenerating epithelia. Thus, EphB/ephrin-B may be a useful marker combination for dysplastic/oncogenic transformation in gastric cancer.
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http://dx.doi.org/10.3748/wjg.v21.i2.453DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4292276PMC
January 2015

Complementary expression and repulsive signaling suggest that EphB2 and ephrin-B1 are possibly involved in epithelial boundary formation at the squamocolumnar junction in the rodent stomach.

Histochem Cell Biol 2013 Dec 24;140(6):659-75. Epub 2013 Jul 24.

Laboratory of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano, Osaka, 598-8531, Japan,

Eph receptors and ephrin ligands are cell-cell communication molecules with well-defined roles in cell adhesion, migration, and tissue boundary formation. However, their expression levels in the squamocolumnar epithelial junction region at the distal esophagus are completely unknown. We examined EphB2 and ephrin-B1 localization in the squamocolumnar epithelial junction region between the proximal and distal stomach of the rodents. Immunostaining showed complimentary expression patterns along the proximal-to-distal axis of the gastric epithelia across the junction: EphB2 expression was maximal around the epithelial junction and sharply decreased in the stratified squamous epithelium at a short distance from the junction, whereas ephrin-B1 was strongly expressed in the stratified squamous epithelium at a distance from the junction and sharply decreased toward the junction. These expression patterns suggest that EphB2/ephrin-B1 signaling occurs preferentially in the epithelia across the junction, where the receptor and ligand expression highly overlap. We also show that (1) EphB2 preferentially binds ephrin-B1, and (2) cell repulsion/lateral migration was induced in primary cultured gastric keratinocytes on ephrin-B1-Fc- and EphB2-Fc-coated surfaces. On the basis of these findings, we propose that EphB2 and ephrin-B1 are possibly involved in epithelial boundary formation at the squamocolumnar junction.
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http://dx.doi.org/10.1007/s00418-013-1129-2DOI Listing
December 2013
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