Details of a Researcher - Soga, Tomoyoshi

Papers - Soga, Tomoyoshi

Division display 121 - 140 of about 417 ／ All the affair displays >>

Effects of feed crops and boiling on chicken egg yolk and white determined by a metabolome analysis

Ogura T., Wakayama M., Ashino Y., Kadowaki R., Sato M., Soga T., Tomita M.

Food Chem. 327 127077 2020.10

Research paper (scientific journal), Joint Work, Accepted, ISSN 03088146

Compositional analyses of eggs have primarily focused on nutritional components, including large molecules, such as proteins. However, few reports have investigated the effects of heating and hen feed crops on taste components, such as free amino acids and sugars. Herein, water-soluble metabolites in raw and boiled eggs produced from chickens raised with corn- or rice-fed were analyzed. Each egg was separated into yolk and white, and freeze-dried samples were analyzed by CE-MS and LC-MS. Abundant metabolites included amino acids in yolks and sugars in whites. Compared to corn-fed, rice-fed resulted in three times higher betaine and uridine monophosphate concentrations in yolks and whites, respectively. Boiled whites contained more than four times higher concentrations of amino acids and fructose than raw whites. Metabolites in yolks exhibited minimal changes after boiling. Our findings support the use of water-soluble metabolomics to evaluate the effects of heating and feed crops on taste components.

Access to Document (DOI)

Proteomic and metabolomic analyses uncover sex-specific regulatory pathways in mouse fetal germline differentiation

Hayashi, Y., Mori, M., Igarashi, K., Tanaka, K., Takehara, A., Ito-Matsuoka, Y., Kanai, A., Yaegashi, N., Soga, T., Matsui, Y.

Biol. Reprod. 103 ( 4 ) 717 - 735 2020.10

Research paper (scientific journal), Joint Work, Accepted, ISSN 00063363

Regulatory mechanisms of germline differentiation have generally been explained via the function of signaling pathways, transcription factors, and epigenetic regulation; however, little is known regarding proteomic and metabolomic regulation and their contribution to germ cell development. Here, we conducted integrated proteomic and metabolomic analyses of fetal germ cells in mice on embryonic day (E)13.5 and E18.5 and demonstrate sex- and developmental stage-dependent changes in these processes. In male germ cells, RNA processing, translation, oxidative phosphorylation, and nucleotide synthesis are dominant in E13.5 and then decline until E18.5, which corresponds to the prolonged cell division and more enhanced hyper-transcription/translation in male primordial germ cells and their subsequent repression. Tricarboxylic acid cycle and one-carbon pathway are consistently upregulated in fetal male germ cells, suggesting their involvement in epigenetic changes preceding in males. Increased protein stability and oxidative phosphorylation during female germ cell differentiation suggests an upregulation of aerobic energy metabolism, which likely contributes to the proteostasis required for oocyte maturation in subsequent stages. The features elucidated in this study shed light on the unrevealed mechanisms of germ cell development.

Access to Document (DOI)

Kinetic Trans-omic Analysis Reveals Key Regulatory Mechanisms for Insulin-Regulated Glucose Metabolism in Adipocytes

Ohno, S., Quek, L.E., Krycer, J.R., Yugi, K., Hirayama, A., Ikeda, S., Shoji, F., Suzuki, K., Soga, T., James, D.E., Kuroda, S.

iScience 23 ( 9 ) 101479 2020.09

Research paper (scientific journal), Joint Work, Accepted

Insulin regulates glucose metabolism through thousands of regulatory mechanisms; however, which regulatory mechanisms are keys to control glucose metabolism remains unknown. Here, we performed kinetic trans-omic analysis by integrating isotope-tracing glucose flux and phosphoproteomic data from insulin-stimulated adipocytes and built a kinetic mathematical model to identify key allosteric regulatory and phosphorylation events for enzymes. We identified nine reactions regulated by allosteric effectors and one by enzyme phosphorylation and determined the regulatory mechanisms for three of these reactions. Insulin stimulated glycolysis by promoting Glut4 activity by enhancing phosphorylation of AS160 at S595, stimulated fatty acid synthesis by promoting Acly activity through allosteric activation by glucose 6-phosphate or fructose 6-phosphate, and stimulated glutamate synthesis by alleviating allosteric inhibition of Gls by glutamate. Most of glycolytic reactions were regulated by amounts of substrates and products. Thus, phosphorylation or allosteric modulator-based regulation of only a few key enzymes was sufficient to change insulin-induced metabolism.

Access to Document (DOI)

Insulin signaling requires glucose to promote lipid anabolism in adipocytes

Krycer J.R., Quek L.E., Francis D., Zadoorian A., Weiss F.C., Cooke K.C., Nelson M.E., Diaz-Vegas A., Humphrey S.J., Scalzo R., Hirayama A., Ikeda S., Shoji F., Suzuki K., Huynh K., Giles C., Varney B., Nagarajan S.R., Hoy A.J., Soga T., Meikle P.J., Cooney G.J., Fazakerley D.J., James D.E.

J. Biol. Chem. 295 ( 38 ) 13250 - 13266 2020.09

Research paper (scientific journal), Joint Work, Accepted

Adipose tissue is essential for metabolic homeostasis, balancing lipid storage and mobilization based on nutritional status. This is coordinated by insulin, which triggers kinase signaling cascades to modulate numerous metabolic proteins, leading to increased glucose uptake and anabolic processes like lipogenesis. Given recent evidence that glucose is dispensable for adipocyte respiration, we sought to test whether glucose is necessary for insulin-stimulated anabolism. Examining lipogenesis in cultured adipocytes, glucose was essential for insulin to stimulate the synthesis of fatty acids and glyceride-glycerol. Importantly, glucose was dispensable for lipogenesis in the absence of insulin, suggesting that distinct carbon sources are used with or without insulin. Metabolic tracing studies revealed that glucose was required for insulin to stimulate pathways providing carbon substrate, NADPH, and glycerol 3-phosphate for lipid synthesis and storage. Glucose also displaced leucine as a lipogenic substrate and was necessary to suppress fatty acid oxidation. Together, glucose provided substrates and metabolic control for insulin to promote lipogenesis in adipocytes. This contrasted with the suppression of lipolysis by insulin signaling, which occurred independently of glucose. Given previous observations that signal transduction acts primarily before glucose uptake in adipocytes, these data are consistent with a model whereby insulin initially utilizes protein phosphorylation to stimulate lipid anabolism, which is sustained by subsequent glucose metabolism. Consequently, lipid abundance was sensitive to glucose availability, both during adipogenesis and in Drosophila flies in vivo Together, these data highlight the importance of glucose metabolism to support insulin action, providing a complementary regulatory mechanism to signal transduction to stimulate adipose anabolism.

Access to Document (DOI)

Comparison of the ischemic and non-ischemic lung cancer metabolome reveals hyper activity of the TCA cycle and autophagy

Kikuchi, N., Soga, T., Nomura, M., Sato, T., Sakamoto, Y., Tanaka, R., Abe, J., Morita, M., Shima, H., Okada, Y., Tanuma, N

Biochem. Biophys. Res. Commun. 530 ( 1 ) 285 - 291 2020.09

Research paper (scientific journal), Joint Work, Accepted, ISSN 0006291X

Recent advances in cancer biology reveal the importance of metabolic changes in cancer; however, less is known about how metabolic pathways in tumors are regulated in vivo. Here, we report analysis of the lung cancer metabolism based on different surgical procedures, namely lobectomy and partial resection. In lobectomy, but not in partial resection, pulmonary arteries and veins are ligated prior to removal of tissues, rendering tissues ischemic. We show that tumors indeed undergo ischemia upon lobectomy and that the tumor metabolome differs markedly from that of tumors removed by partial resection. Comparison of the responses to ischemia in tumor and normal lung tissues revealed that lung cancer tissue exhibits greater TCA cycle and autophagic activity than do normal lung tissues in vivo in patients. Finally, we report that deleting ATG7, which encodes a protein essential for autophagy, antagonizes growth of tumors derived from lung cancer cell lines, suggesting that autophagy confers metabolic advantages to lung cancer. Our findings shed light on divergent metabolic responses to ischemia seen in tumors and normal tissues.

Access to Document (DOI)

Pharmacologically targetable vulnerability in prostate cancer carrying RB1-SUCLA2 deletion

Kohno, S., Linn, P. , Nagatani, N., Watanabe, Y., Kumar, S., Soga, T., Takahashi, C.

Oncogene 39 ( 10 ) 5690 - 5707 2020.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 09509232

RB1 gene is often homozygously deleted or mutated in prostate adenocarcinomas following acquirement of castration resistance and/or metastatic ability. We found that SUCLA2 gene is frequently involved in the deletion of the RB1 gene region in advanced prostate cancer. SUCLA2 constitutes the β-subunit of succinate CoA ligase heterodimer that reversibly converts succinyl CoA into succinate. We sought the possibility that deletion of SUCLA2 gives rise to a metabolic vulnerability that could be targeted therapeutically. We found a significant metabolic shift in SUCLA2-deleted prostate cancer cells, including lower mitochondrial respiratory activity. By screening a number of libraries for compounds that induce cell death selectively in SUCLA2-deficient prostate cancer cells, we identified thymoquinone (2-isopropyl-5-methylbenzo-1,4-quinone) and PMA (phorbol-12-myristate-13-acetate) from a natural compound library. These findings indicate that the metabolic vulnerability in SUCLA2-deficient prostate cancer cells is pharmacologically targetable.

Access to Document (DOI)

EVI1 triggers metabolic reprogramming associated with leukemogenesis and increases sensitivity to L-asparaginase

Saito, Y., Sawa, D., Kinoshita, M., Yamada, A., Kamimura, S., Suekane, A., Ogoh, H., Matsuo, H., Adachi, S., Taga, T., Tomizawa, D., Osato, M., Soga, T., Morishita, K., Moritake, H.

Haematologica 105 ( 8 ) 2118 - 2129 2020.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 03906078

Metabolic reprogramming of leukemia cells is important for survival, proliferation, and drug resistance under conditions of metabolic stress in the bone marrow. Deregulation of cellular metabolism, leading to development of leukemia, occurs through abnormally high expression of transcription factors such as MYC and Ecotropic Virus Integration site 1 protein homolog (EVI1). Overexpression of EVI1 in adults and children with mixed lineage leukemia-rearrangement acute myeloid leukemia (MLL-r AML) has a very poor prognosis. To identify a metabolic inhibitor for EVI1-induced metabolic reprogramming in MLL-r AML, we used an XFp extracellular flux analyzer to examine metabolic changes during leukemia development in mouse models of AML expressing MLL-AF9 and Evi1 (Evi1/MF9). Oxidative phosphorylation (OXPHOS) in Evi1/MF9 AML cells accelerated prior to activation of glycolysis, with a higher dependency on glutamine as an energy source. Furthermore, EVI1 played a role in glycolysis as well as driving production of metabolites in the tricarboxylic acid cycle. L-asparaginase (L-asp) exacerbated growth inhibition induced by glutamine starvation and suppressed OXPHOS and proliferation of Evi1/MF9 both in vitro and in vivo; high sensitivity to L-asp was caused by low expression of asparagine synthetase (ASNS) and L-asp-induced suppression of glutamine metabolism. In addition, samples from patients with EVI1+MF9 showed low ASNS expression, suggesting that it is a sensitive marker of L-asp treatment. Clarification of metabolic reprogramming in EVI1+ leukemia cells may aid development of treatments for EVI1+MF9 refractory leukemia.

Copyright© 2020 Ferrata Storti Foundation.

Access to Document (DOI)

T cell-specific deletion of Pgam1 reveals a critical role for glycolysis in T cell responses

Toriyama, K., Kuwahara, M., Kondoh, H., Mikawa, T., Takemori, N., Konishi, A., Yorozuya, T., Yamada, T., Soga, T., Shiraishi, A., Yamashita, M.

Commun Biol 3 ( 1 ) 394 2020.07

Research paper (scientific journal), Joint Work, Accepted

Although the important roles of glycolysis in T cells have been demonstrated, the regulatory mechanism of glycolysis in activated T cells has not been fully elucidated. Furthermore, the influences of glycolytic failure on the T cell-dependent immune response in vivo remain unclear. We therefore assessed the role of glycolysis in the T cell-dependent immune response using T cell-specific Pgam1-deficient mice. Both CD8 and CD4 T cell-dependent immune responses were attenuated by Pgam1 deficiency. The helper T cell-dependent inflammation was ameliorated in Pgam1-deficient mice. Glycolysis augments the activation of mTOR complex 1 (mTORC1) and the T-cell receptor (TCR) signals. Glutamine acts as a metabolic hub in activated T cells, since the TCR-dependent increase in intracellular glutamine is required to augment glycolysis, increase mTORC1 activity and augment TCR signals. These findings suggest that mTORC1, glycolysis and glutamine affect each other and cooperate to induce T cell proliferation and differentiation.

Access to Document (DOI)

Comprehensive Dipeptide Profiling and Quantitation by Capillary Electrophoresis and Liquid Chromatography Coupled with Tandem Mass Spectrometry

Ozawa, H., Hirayama, A., Ishikawa, T., Kudo, R., Maruyama, M., Shoji, F., Doke, T., Ishimoto, T., Maruyama, S., Soga, T., Tomita, M.

Anal. Chem. 92 ( 14 ) 9799 - 9806 2020.07

Research paper (scientific journal), Joint Work, Accepted, ISSN 00032700

Dipeptides have attracted much attention as post-amino acids with physical properties and functions different from those of amino acids. However, a given dipeptide cannot be distinguished by mass spectrometry from its structural isomer with an opposite amino acid binding order unless these isomers are separated before introduction, which complicates the comprehensive analysis of dipeptides. Herein, a novel analytical platform for dipeptide analysis by capillary electrophoresis tandem mass spectrometry and liquid chromatography tandem mass spectrometry is developed. This method is used to quantitate 335 dipeptides and achieves excellent separation of structural isomers with opposite binding orders, high correlation coefficients, and low instrumental detection limits (0.088-83.1 nM). Moreover, acceptable recoveries (70-135%) are observed for most tested dipeptides in chicken liver samples spiked both before and after preparation. The developed method is also applied to the quantitation of dipeptides in the livers of mice fed different diets to detect 236 dipeptides, and the shift from a normal diet to a high-fat diet is shown to increase/decrease (p < 0.05, fold-change < 0.5) the contents of 0/29 dipeptides, respectively. The developed method is expected to facilitate the search for new dipeptide applications such as novel functional components of foods and biomarkers of diseases.

Access to Document (DOI)

Local Necrotic Cells Trigger Systemic Immune Activation via Gut Microbiome Dysbiosis in Drosophila

Kosakamoto, H., Yamauchi, T., Akuzawa-Tokita, Y., Nishimura, K., Soga, T., Murakami, T., Mori, H., Yamamoto, K., Miyazaki, R., Koto, A., Miura, M., Obata, F.

Cell Rep. 32 ( 3 ) 107938 2020.07

Research paper (scientific journal), Joint Work

Necrotic cells elicit an inflammatory response through their endogenous factors with damage-associated molecular patterns. Blocking apoptosis in Drosophila wings leads to the necrosis-driven systemic immune response by unknown mechanisms. Here, we demonstrate that immune activation in response to necrotic cells is mediated by commensal gut microbiota. Removing the microbiome attenuates hyperactivation of the innate immune signaling IMD pathway in necrosis-induced flies. Necrotic cells in wings trigger Gluconobacter expansion in the gut. An isolated Gluconobacter sp. strain is sufficient for pathological IMD activation in necrosis-induced flies, while it is not inflammatory for control animals. In addition, bacterial colonization shifts the host metabolome and shortens the lifespan of necrosis-induced flies. This study shows that local necrosis triggers a pathological systemic inflammatory response through interaction between the host and the dysbiotic gut microbiome.

Access to Document (DOI)

The use of a double coaxial electrospray ionization sprayer improves the peak resolutions of anionic metabolites in capillary ion chromatography-mass spectrometry

Hirayama, A., Tabata, S., Kudo, R., Hasebe, M., Suzuki, K., Tomita, M., Soga, T.

J. Chromatogr. A. 1619 460914 2020.05

Research paper (scientific journal), Joint Work, Accepted, ISSN 00219673

Recently, ion chromatography coupled with mass spectrometry has been used for the determination of anionic metabolites. However, connection with a mass spectrometer in this method is not straightforward because backpressure produced by the addition of a make-up solution often affects the peak resolutions of the target metabolites. To overcome this problem, we developed a capillary ion chromatography-mass spectrometry method utilizing a double coaxial electrospray ionization sprayer. This method was not affected by backpressure and the number of theoretical plates was about three times that of a conventional sprayer. Under optimized conditions, 44 anionic metabolites, including organic acids, sugar phosphates, nucleotides, and cofactors, were successfully separated and selectively detected with a Q Exactive mass spectrometer. The calibration curves of the tested metabolites showed excellent linearity within the range of 1-100,000 nmol/L and the correlation coefficient was greater than 0.991. The detection limits for these metabolites were between 1 and 500 nmol/L (0.4 and 200 fmol). The developed method was applied to the quantitation of anionic metabolites in cultured cancer cell samples with tumor necrosis factor (TNF)-α stimulation. This allowed for the successful determination of 105 metabolites. The levels of tricarboxylic acid cycle intermediates changed significantly after TNF-α stimulation. These results demonstrate that the developed method is a promising new tool for comprehensive analysis of anionic metabolites.

Access to Document (DOI)

Paternal restraint stress affects offspring metabolism via ATF-2 dependent mechanisms in Drosophila melanogaster germ cells

Seong, K.H., Ly, N.H., Katou, Y., Yokota, N., Nakato, R., Murakami, S., Hirayama, A., Fukuda, S., Kang, S., Soga, T., Shirahige, K., Ishii, S.

Commun. Biol. 3 ( 1 ) 208 2020.05

Research paper (scientific journal), Joint Work, Accepted

Paternal environmental factors can epigenetically influence gene expressions in offspring. We demonstrate that restraint stress, an experimental model for strong psychological stress, to fathers affects the epigenome, transcriptome, and metabolome of offspring in a MEKK1-dATF2 pathway-dependent manner in Drosophila melanogaster. Genes involved in amino acid metabolism are upregulated by paternal restraint stress, while genes involved in glycolysis and the tricarboxylic acid (TCA) cycle are downregulated. The effects of paternal restraint stress are also confirmed by metabolome analysis. dATF-2 is highly expressed in testicular germ cells, and restraint stress also induces p38 activation in the testes. Restraint stress induces Unpaired 3 (Upd3), a Drosophila homolog of Interleukin 6 (IL-6). Moreover, paternal overexpression of upd3 in somatic cells disrupts heterochromatin in offspring but not in offspring from dATF-2 mutant fathers. These results indicate that paternal restraint stress affects metabolism in offspring via inheritance of dATF-2-dependent epigenetic changes.

Access to Document (DOI)

Effect of blanching on the concentration of metabolites in two parts of Undaria pinnatifida, Wakame (leaf) and Mekabu (sporophyll)

Hamid, S.S., Wakayama, M., Ashino, Y., Kadowaki, R., Soga, T., Tomita, M.

Algal Res. 47 101829 2020.05

Research paper (scientific journal), Joint Work, Accepted, ISSN 22119264

Undaria pinnatifida is a seaweed native to Japan, where it is cultivated and sold commercially as food. Fresh seaweed commonly blanches before consumption. However, the effects of blanching on metabolites present in different parts of U. pinnatifida, namely, Wakame (leaf) and Mekabu (sporophyll), are not well understood. Here, we investigated changes in metabolites in these two seaweed parts after blanching for different periods. The samples were freeze-dried and extracted using methanol-water, and metabolite concentration was quantitated using liquid chromatography mass spectrometry and capillary electrophoresis mass spectrometry. The concentration of most metabolites was the highest in raw samples, decreasing drastically within 20 s of blanching in Wakame and decreasing gradually in Mekabu. In contrast, the concentration of some fatty acids, such as octanoate, increased in both parts. During blanching, seaweed color changed from brown to green, and blanching did not significantly affect amino acid or the sugar composition. Finally, a relationship was found between metabolite and blanching-related characteristics, such as color and drying percentage.

Access to Document (DOI)

Adenosine leakage from perforin-burst extracellular vesicles inhibits perforin secretion by cytotoxic T-lymphocytes

Tadokoro, H., Hirayama, A., Kudo, R., Hasebe, M., Yoshioka, Y., Matsuzaki, J., Yamamoto, Y., Sugimoto, M., Soga, T., Ochiya, T.

PLoS One 15 ( 4 ) e0231430 2020.04

Research paper (scientific journal), Joint Work, Accepted

Extracellular vesicles (EVs) in the tumor microenvironment facilitate intercellular communication. Cancer cell-derived EVs act as an immunosuppressor by transporting cargos and presenting transmembrane proteins. By contrast, CD8+ cytotoxic T-lymphocytes (CTLs) exert anti-cancer cytotoxicity via the pore-forming protein perforin. Here, we hypothesize that although EVs are destroyed by perforin, cancer cell-derived EVs might possess mechanisms that enable them to avoid this destruction. We used a breast cancer cell line, MDA-MB-231-luc-D3H2LN (D3H2LN), to generate EVs. Destruction of the EVs by perforin was demonstrated visually using atomic force microscopy. To investigate immunosuppressive metabolites within cancer cell-derived EVs, we performed metabolomic profiling of EVs from D3H2LN cells cultured for 48 h with or without IFN-γ, which induces metabolic changes in the cells. We found that both types of EV from IFN-γ treated D3H2LN cells and non-treated D3H2LN cells contained adenosine, which has immunosuppressive effects. When we exposed cancer cell-derived EVs to CTLs, perforin secretion by CTLs fell significantly. In addition, the decreases in perforin secretion were ameliorated by treatment with adenosine deaminase, which degrades extracellular adenosine. Taken together, these results suggest that after perforin secreted by CTLs disrupts the membrane of EVs, adenosine released from the EVs acts as an immunosuppressive metabolite by binding to the adenosine receptor on the CTL membrane. This mechanism provides a novel survival strategy using cancer cell-derived EVs.

Access to Document (DOI)

Sensory properties and metabolomic profiles of dry-cured ham during the ripening process

Sugimoto M., Sugawara T., Obiya S., Enomoto A., Kaneko M., Ota S., Soga T., Tomita M.

Food Res Int. 129 108850 2020.03

Research paper (scientific journal), Joint Work, Accepted, ISSN 09639969

Dry-cured ham with a long ripening period is a valuable product worldwide. Ripening time is a key determinant of the endogenous metabolites that characterize the flavor and taste of ham products. While various studies have analyzed the relationship between ripening duration and sensory characteristics, no studies have evaluated ham products produced in Japan. Here, we conducted time-course metabolomic profiling, taste sensor-based analyses, and sensory evaluations by non-trained consumers during ripening. Capillary electrophoresis-mass spectrometry was used to quantify non-volatile metabolites, such as amino acids, organic acids, and nucleotides. In an analysis of eight time-points during 680 days of ripening, the highest score for the after-taste of umami was observed on day 540, despite subtle changes in the scores for other properties. The concentrations of aspartic acid and glutamic acid relative to those of total amino acids were the highest at this point. This approach can contribute to the understanding of the relationship between the metabolite profile and ripening duration.

Access to Document (DOI)

Dynamic 13C Flux Analysis Captures the Reorganization of Adipocyte Glucose Metabolism in Response to Insulin

Quek, L.E., Krycer, J.R., Ohno, S., Yugi, K., Fazakerley, D.J., Scalzo, R., Elkington, S.D., Dai, Z., Hirayama, A., Ikeda, S., Shoji, F., Suzuki, K., Locasale, J.W., Soga, T., James, D.E., Kuroda, S.

iScience 23 ( 2 ) 100855 2020.02

Research paper (scientific journal), Joint Work, Accepted

Cellular metabolism is dynamic, but quantifying non-steady metabolic fluxes by stable isotope tracers presents unique computational challenges. Here, we developed an efficient 13C-tracer dynamic metabolic flux analysis (13C-DMFA) framework for modeling central carbon fluxes that vary over time. We used B-splines to generalize the flux parameterization system and to improve the stability of the optimization algorithm. As proof of concept, we investigated how 3T3-L1 cultured adipocytes acutely metabolize glucose in response to insulin. Insulin rapidly stimulates glucose uptake, but intracellular pathways responded with differing speeds and magnitudes. Fluxes in lower glycolysis increased faster than those in upper glycolysis. Glycolysis fluxes rose disproportionally larger and faster than the tricarboxylic acid cycle, with lactate a primary glucose end product. The uncovered array of flux dynamics suggests that glucose catabolism is additionally regulated beyond uptake to help shunt glucose into appropriate pathways. This work demonstrates the value of using dynamic intracellular fluxes to understand metabolic function and pathway regulation.

Access to Document (DOI)

A FLCN-TFE3 Feedback Loop Prevents Excessive Glycogenesis and Phagocyte Activation by Regulating Lysosome Activity

Endoh, M., Baba, M., Endoh, T., Hirayama, A., Nakamura-Ishizu, A., Umemoto, T., Hashimoto, M., Nagashima, K., Soga, T., Lang, M., Schmidt, L.S., Linehan, W.M., Suda, T.

Cell Rep. 30 ( 6 ) 1823 - 1834 2020.02

Research paper (scientific journal), Joint Work, Accepted

The tumor suppressor folliculin (FLCN) suppresses nuclear translocation of TFE3, a master transcription factor for lysosomal biogenesis, via regulation of amino-acid-sensing Rag GTPases. However, the importance of this lysosomal regulation in mammalian physiology remains unclear. Following hematopoietic-lineage-specific Flcn deletion in mice, we found expansion of vacuolated phagocytes that accumulate glycogen in their cytoplasm, phenotypes reminiscent of lysosomal storage disorder (LSD). We report that TFE3 acts in a feedback loop to transcriptionally activate FLCN expression, and FLCN loss disrupts this loop, augmenting TFE3 activity. Tfe3 deletion in Flcn knockout mice reduces the number of phagocytes and ameliorates LSD-like phenotypes. We further reveal that TFE3 stimulates glycogenesis by promoting the expression of glycogenesis genes, including Gys1 and Gyg, upon loss of Flcn. Taken together, we propose that the FLCN-TFE3 feedback loop acts as a rheostat to control lysosome activity and prevents excessive glycogenesis and LSD-like phagocyte activation.

Access to Document (DOI)

The guanylate cyclase C agonist linaclotide ameliorates the gut-cardio-renal axis in an adenine-induced mouse model of chronic kidney disease

Nanto-Hara F., Kanemitsu Y., Fukuda S., Kikuchi K., Asaji K., Saigusa D., Iwasaki T., Ho H.J., Mishima E., Suzuki T., Suzuki C., Tsukimi T., Matsuhashi T., Oikawa Y., Akiyama Y., Kure S., Owada Y., Tomioka Y., Soga T., Ito S., Abe T.

Nephrol. Dial. Transplant. 35 ( 2 ) 250 - 264 2020.02

Research paper (scientific journal), Joint Work, ISSN 09310509

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.

Access to Document (DOI)

Lactate production is a prioritized feature of adipocyte metabolism

Krycer, J.R., Quek, L.E., Francis, D.J., Fazakerley, S.D., Elkington, S., Diaz-Vegas, A., Cooke, K.C., Weiss, F.C., Duan, X., Kurdyukov, S., Zhou, P.X., Tambar, U.,K. Hirayama, A., Ikeda, S., Kamei, Y., Soga, T., Cooney, G.J., James, D.E.

J Biol Chem. 295 ( 1 ) 83 - 98 2020.01

Research paper (scientific journal), Joint Work, Accepted, ISSN 00219258

Adipose tissue is essential for whole-body glucose homeostasis, with a primary role in lipid storage. It has been previously observed that lactate production is also an important metabolic feature of adipocytes, but its relationship to adipose and whole-body glucose disposal remains unclear. Therefore, using a combination of metabolic labeling techniques, here we closely examined lactate production of cultured and primary mammalian adipocytes. Insulin treatment increased glucose uptake and conversion to lactate, with the latter responding more to insulin than did other metabolic fates of glucose. However, lactate production did not just serve as a mechanism to dispose of excess glucose, because we also observed that lactate production in adipocytes did not solely depend on glucose availability and even occurred independently of glucose metabolism. This suggests that lactate production is prioritized in adipocytes. Furthermore, knocking down lactate dehydrogenase specifically in the fat body of Drosophila flies lowered circulating lactate and improved whole-body glucose disposal. These results emphasize that lactate production is an additional metabolic role of adipose tissue beyond lipid storage and release.

Access to Document (DOI)

Inosine pranobex enhances human NK cell cytotoxicity by inducing metabolic activation and NKG2D ligand expression

McCarthy, MT., Lin, D., Soga, T., Adam, J., O'Callaghan, CA.

Eur. J. Immunol. 50 ( 1 ) 130 - 137 2020.01

Research paper (scientific journal), Joint Work, Accepted, ISSN 00142980

Inosine pranobex (IP) is a synthetic immunomodulating compound, indicated for use in the treatment of human papillomavirus-associated warts and subacute sclerosing panencephalitis. Previous studies demonstrate that the immunomodulatory activity of IP is characterized by enhanced lymphocyte proliferation, cytokine production, and NK cell cytotoxicity. The activation of NKG2D signaling on NK cells, CD8+ T cells, and γδ T cells also produces these outcomes. We hypothesized that IP alters cellular immunity through the induction of NKG2D ligand expression on target cells, thereby enhancing immune cell activation through the NKG2D receptor. We tested this hypothesis and show that exposure of target cells to IP leads to increased expression of multiple NKG2D ligands. Using both targeted metabolic interventions and unbiased metabolomic studies, we found that IP causes an increase in intracellular concentration of purine nucleotides and tricarboxylic acid (TCA) cycle intermediates and NKG2D ligand induction. The degree of NKG2D ligand induction was functionally significant, leading to increased NKG2D-dependent target cell immunogenicity. These findings demonstrate that the immunomodulatory properties of IP are due to metabolic activation with NKG2D ligand induction.

Access to Document (DOI)

　 Previous page - Next page 　