Faculty Profiles - TOYOKUNI Shinya

Sleep-wake patterns are altered with age, Prdm13 signaling in the DMH, and diet restriction in mice. Reviewed International journal Open Access

Shogo Tsuji, Cynthia S Brace, Ruiqing Yao, Yoshitaka Tanie, Hirobumi Tada, Nicholas Rensing, Seiya Mizuno, Julio Almunia, Yingyi Kong, Kazuhiro Nakamura, Takahisa Furukawa, Noboru Ogiso, Shinya Toyokuni, Satoru Takahashi, Michael Wong, Shin-Ichiro Imai, Akiko Satoh

Life science alliance Vol. 6 ( 6 ) 2023.6

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

Old animals display significant alterations in sleep-wake patterns such as increases in sleep fragmentation and sleep propensity. Here, we demonstrated that PR-domain containing protein 13 (Prdm13)+ neurons in the dorsomedial hypothalamus (DMH) are activated during sleep deprivation (SD) in young mice but not in old mice. Chemogenetic inhibition of Prdm13+ neurons in the DMH in young mice promotes increase in sleep attempts during SD, suggesting its involvement in sleep control. Furthermore, DMH-specific Prdm13-knockout (DMH-Prdm13-KO) mice recapitulated age-associated sleep alterations such as sleep fragmentation and increased sleep attempts during SD. These phenotypes were further exacerbated during aging, with increased adiposity and decreased physical activity, resulting in shortened lifespan. Dietary restriction (DR), a well-known anti-aging intervention in diverse organisms, ameliorated age-associated sleep fragmentation and increased sleep attempts during SD, whereas these effects of DR were abrogated in DMH-Prdm13-KO mice. Moreover, overexpression of Prdm13 in the DMH ameliorated increased sleep attempts during SD in old mice. Therefore, maintaining Prdm13 signaling in the DMH might play an important role to control sleep-wake patterns during aging.

DOI： 10.26508/lsa.202301992

Matrigel-based organoid culture of malignant mesothelioma reproduces cisplatin sensitivity through CTR1. Reviewed International journal Open Access

Fumiya Ito, Katsuhiro Kato, Izumi Yanatori, Yuki Maeda, Toyoaki Murohara, Shinya Toyokuni

BMC cancer Vol. 23 ( 1 ) page： 487 - 487 2023.5

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

Organoids are a three-dimensional (3D) culture system that simulate actual organs. Therefore, tumor organoids are expected to predict precise response to chemotherapy in patients. However, to date, few studies have studied the drug responses in organoids of malignant mesothelioma (MM). The poor prognosis of MM emphasizes the importance of establishing a protocol for generating MM-organoid for research and clinical use. Here, we established murine MM organoids from p53+/- or wild-type C57BL/6 strain by intraperitoneal injection either with crocidolite or carbon nanotube. Established MM-organoids proliferated in Matrigel as spheroids. Subcutaneous injection assays revealed that the MM-organoids mimicked actual tissue architecture and maintained the original histological features of the primary MM. RNA sequencing and pathway analyses revealed that the significant expressional differences between the 2D- and 3D-culture systems were observed in receptor tyrosine kinases, including IGF1R and EGFR, glycosylation and cholesterol/steroid metabolism. MM-organoids exhibited a more sensitive response to cisplatin through stable plasma membrane localization of a major cisplatin transporter, copper transporter 1/Slc31A1 (Ctr1) in comparison to 2D-cultures, presumably through glycosylation and lipidation. The Matrigel culture system facilitated the localization of CTR1 on the plasma membrane, which simulated the original MMs and the subcutaneous xenografts. These results suggest that the newly developed protocol for MM-organoids is useful to study strategies to overcome chemotherapy resistance to cisplatin.

DOI： 10.1186/s12885-023-10966-4

Organic decomposition and synthesis reactions in lactated solution exposed to nonequilibrium atmospheric pressure plasma Reviewed International journal

Liu Y., Ishikawa K., Tanaka H., Miron C., Kondo T., Nakamura K., Mizuno M., Kajiyama H., Toyokuni S., Hori M.

Plasma Processes and Polymers Vol. 20 ( 5 ) 2023.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Plasma Processes and Polymers

Lactate is used in the food and pharmaceutical industries and is a crucial intermediate for synthesis. Plasma-activated lactate (PAL) in Ringer's solution was recently shown to have effective antitumor action. Small molecule aldehydes, ketones, and organic acids were produced from lactate during plasma exposure, and five-membered conjugated lactone isomers of furanone (C5H6O2) were detected formed by interactions of lactate or its fragments with •OH, organic radicals, and H2O2. 2,3-Dimethyl-tartaric acid may be the effective component in PAL for the selective killing of cancer but not normal cells and possible pathways for its synthesis are provided. Aqueous reaction mechanisms are explained, including dehydration, esterification, hydrolysis, and dimerization. This study will help develop novel cancer therapies and further plasma organic chemistry.

DOI： 10.1002/ppap.202200193

Field-effect transistor antigen/antibody-TMDs sensors for the detection of COVID-19 samples. Reviewed International journal Open Access

Ruben Canton-Vitoria, Kotaro Sato, Yashiro Motooka, Shinya Toyokuni, Zheng Liu, Ryo Kitaura

Nanoscale Vol. 15 ( 9 ) page： 4570 - 4580 2023.3

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

We fabricated sensors by modifying the surface of MoS2 and WS2 with COVID-19 antibodies and investigated their characteristics, including stability, reusability, sensitivity, and selectivity. Thiols and disulfanes in antibodies strongly interact with vacant Mo or W sites of MoS2 or WS2, yielding durable devices that are stable for several days in the air or water. More importantly, detachment of the antibodies is suppressed even during the aggressive cleaning process of the devices at pH 3, which allows reusing the same device in several experiments without appreciable loss of sensitivity. Therefore, the nanodevice may be employed in samples of different patients. Further, we found a limit of detection (LOD) of 1 fg ml-1 at room temperature, time responses of 1 second, and selectivity against interferences such as KLH protein or Albumin.

DOI： 10.1039/d2nr06630k

BRCA2生殖細胞系列変異が卵巣予備能低下へ及ぼす影響について Reviewed International journal

田中秀明, 本岡大社, 前田勇貴, 真下知士, 梶山広明, 豊國伸哉

日本病理学会会誌 Vol. 112 ( 1 ) page： 370 - 370 2023.3

卵巣における細胞外小胞を介した鉄代謝と酸化ストレス応答の解析 Reviewed International journal

加藤大暉, 本岡大社, 豊國伸哉

日本病理学会会誌 Vol. 112 ( 1 ) page： 382 - 382 2023.3

タルクによる細胞外小胞を介した卵巣の鉄代謝の撹乱と発がん性 Reviewed International journal

本岡大社, 加藤大暉, 豊國伸哉

日本病理学会会誌 Vol. 112 ( 1 ) page： 256 - 256 2023.3

DNA oxidative damage caused by the aromatic amine MOCA —Examination of 8-hydroxy-2’-deoxyguanosine levels in rat liver— International journal

KOBAYASHI Saho, MOTOOKA Yashiro, KASHIWAGI Hiroki, TOYOKUNI Shinya

Journal of Occupational Safety and Health Vol. 16 ( 1 ) page： 45 - 49 2023.2

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：National Institute of Occupational Safety and Health, Japan

<p>MOCA (4,4’-methylenebis (2-chloroaniline)) , an aromatic amine, is industrially used as a curing agent for urethane resins; however, it is classified as a Group 1 compound (carcinogenic to humans) by the International Agency for Research on Cancer, and there is concern regarding its health effects on workers. The mechanism underlying MOCA-mediated carcinogenesis is thought to be related to DNA damage caused by reactive oxygen species (ROS) and DNA adducts, which are mainly generated during metabolism in the liver. 8-Oxoguanine (8-OHdG), a product of ROS-induced oxidation, occurs at high frequency and can induce G→T transversion mutations during DNA replication. However, to the best of our knowledge, no study has examined whether MOCA induces the formation of highly mutagenic 8-OHdG in experimental animals. Here, F344 rats were orally exposed to 0, 0.4, 2, 10, or 50 mg/kg/day MOCA three times a week for 2 weeks; this is expected to exert toxicity through the hepatic metabolism of MOCA. Livers obtained from these animals were examined for pathology and 8-OHdG levels. In pathological sections, vacuolar degeneration was observed with 50 mg/kg/day MOCA. Further, MOCA-induced 8-OHdG levels showed a slight increasing trend, except at 0.4 mg/kg/day. However, none of these differences were significant. Thus, 8-OHdG is unlikely the main cause of carcinogenesis.</p>

DOI： 10.2486/josh.josh-2022-0022-ta

CiNii Research

Toward the next century of the Nagoya Journal of Medical Science: message from the Editor-in-chief. Reviewed International journal

Toyokuni S

Nagoya journal of medical science Vol. 85 ( 1 ) page： 1 - 4 2023.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Nagoya Journal of Medical Science

It is my great pleasure and honor as the Editor-in-chief to congratulate the centennial anniversary of the Nagoya Journal of Medical Science in 2023 with all the editorial board members and the technical staffs as well as the authors and the readers. One hundred years are quite a long period, and the persistent publication from a medical school of national university in Japan has not been so easy. Especially, the publication was suspended from 1940 to 1950 due to the World War II.

DOI： 10.18999/nagjms.85.1.1

Plasma activated Ringer's lactate solution. Reviewed International journal

Tanaka H, Mizuno M, Ishikawa K, Miron C, Okazaki Y, Toyokuni S, Nakamura K, Kajiyama H, Hori M

Free radical research Vol. 57 ( 1 ) page： 14 - 20 2023.1

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

Low-temperature plasma (LTP) has been widely used in life science. Plasma-activated solutions were defined as solutions irradiated with LTP, and water, medium, and Ringer’s solutions have been irradiated with LTP to produce plasma-activated solutions. They contain chemical compounds produced by reactions among LTP, air, and solutions. Reactive oxygen and nitrogen species (RONS) are major components in plasma-activated solutions and recent studies revealed that plasma-activated organic compounds are produced in plasma-activated Ringer’s lactate solution (PAL). Many in vitro and in vivo studies demonstrated that PAL exhibits anti-tumor effects on cancers, and biochemical analyses revealed intracellular molecular mechanisms of cancer cell death by PAL.

DOI： 10.1080/10715762.2023.2182663

Low-temperature plasma as magic wand to differentiate between the good and the evil. Reviewed International journal

Shinya Toyokuni, Hao Zheng, Yingyi Kong, Kotaro Sato, Kae Nakamura, Hiromasa Tanaka, Yasumasa Okazaki

Free radical research Vol. 57 ( 1 ) page： 38 - 46 2023.1

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

Plasma is the fourth physical state of matter, characterized by an ionized gaseous mixture, after solid, liquid, and gas phases, and contains a wide array of components such as ions, electrons, radicals, and ultraviolet ray. Whereas the sun and thunder are typical natural plasma, recent progress in the electronics enabled the generation of body-temperature plasma, designated as low-temperature plasma (LTP) or non-thermal plasma since the 1990s. LTP has attracted the attention of researchers for possible biological and medical applications. All the living species on earth utilize water as essential media for solvents and molecular transport. Thus, biological application of LTP naturally intervenes water whether LTP is exposed directly or indirectly, where plasma-activated lactate (PAL) is a standard, containing H2O2, NO2- and other identified molecules. Electron spin resonance and immunohistochemical studies demonstrated that LTP exposure is a handy method to load local oxidative stress. Cancer cells are characterized by persistent self-replication and high cytosolic catalytic Fe(II). Therefore, both direct exposure of LTP and PAL can provide higher damage to cancer cells in comparison to non-tumorous cells, which has been demonstrated in a variety of cancer types. The cell death mode is either apoptosis or ferroptosis, depending on the cancer-type. Thus, LTP and PAL are expected to work as an additional cancer therapy to the established guideline protocols, especially for use in somatic cavities or surgical margins.

DOI： 10.1080/10715762.2023.2190860

Extracellular fine particles and carcinogenesis Reviewed International journal

Toyokuni Shinya

Vol. 95 ( 2 ) page： 177 - 183 2023

Thioredoxin deficiency increases oxidative stress and causes bilateral symmetrical degeneration in rat midbrain. Reviewed International journal Open Access

Iori Ohmori, Mamoru Ouchida, Hirohiko Imai, Saeko Ishida, Shinya Toyokuni, Tomoji Mashimo

Neurobiology of disease Vol. 175 page： 105921 - 105921 2022.12

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

Thioredoxin, encoded by Txn1, acts as a critical antioxidant in the defense against oxidative stress by regulating the dithiol/disulfide balance of interacting proteins. The role of thioredoxin in the central nervous system (CNS) is largely unknown. A phenotype-driven study of N-ethyl-N-nitrosourea-mutated rats with wild-running seizures revealed the importance of Txn1 mutations in CNS degeneration. Genetic mapping identified Txn1-F54L in the epileptic rats. The insulin-reducing activity of Txn1-F54L was approximately one-third of that of the wild-type (WT). Bilateral symmetrical vacuolar degeneration in the midbrain, mainly in the thalamus and the inferior colliculus, was observed in the Txn1-F54L rats. The lesions displayed neuronal and oligodendrocytic cell death. Neurons in Txn1-F54L rats showed morphological changes in the mitochondria. Vacuolar degeneration peaked at five weeks of age, and spontaneous repair began at seven weeks. The TUNEL assay showed that fibroblasts derived from homozygotes were susceptible to cell death under oxidative stress. In five-week-old WT rats, energy metabolism in the thalamus was significantly higher than that in the cerebral cortex. In conclusion, in juvenile rats, Txn1 seems to play an essential role in reducing oxidative stress in the midbrains with high energy metabolism.

DOI： 10.1016/j.nbd.2022.105921

RhoA and vigilin are candidates for immunohistochemical markers for epithelioid malignant mesothelioma. International journal Open Access

Hiratsuka T, Yamamoto T, Yoshizawa A, Toyokuni S, Tsuruyama T

Scientific reports Vol. 12 ( 1 ) page： 18519 2022.11

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

Diagnostic markers of malignant mesothelioma (MM) have been extensively investigated. Immunohistochemistry (IHC) markers, such as calretinin, have been used for pathologic diagnosis. However, more diagnostic markers are required to improve the specificity and sensitivity of pathologic diagnosis. This study proposed two proteins as diagnostic markers for epithelioid MM. One is RhoA, an MM mutation-susceptible locus-derived protein, and another is vigilin, a lung small cell carcinoma marker. IHC was performed using 93 MM (epithelioid, 71 cases; sarcomatoid, 13 cases; and biphasic, 9 cases), 64 lung adenocarcinoma (LAC), 60 lung squamous cell carcinoma (LSC), and 14 normal mesothelial (NM) tissues. The majority of epithelioid MM cases were positive for both RhoA and vigilin, whereas both IHCs showed lower stainability in biphasic and sarcomatoid MM. Besides, both IHCs showed significantly higher stainability for RhoA and vigilin in epithelioid MM than in LAC and LSC (p < 0.05). Chi-square tests showed that both RhoA and vigilin IHC positive rate in epithelioid MM was not significantly different from that of calretinin (p > 0.05). In the differential diagnosis of MM from lung cancer, the accuracy and specificity of RhoA, vigilin, and calretinin staining were almost equivalent. Further, H-score test showed that there was no significant difference between RhoA versus calretinin and vigilin versus calretinin in IHC positivity in epithelioid MM (p > 0.05). In conclusion, RhoA and vigilin may be candidates for immunohistochemical markers for epithelioid MM.

DOI： 10.1038/s41598-022-20334-0

Molecular hydrogen has a positive impact on pregnancy maintenance through enhancement of mitochondrial function and immunomodulatory effects on T cells. Reviewed International journal

Chieko Aoki, Kenji Imai, Teruyuki Mizutani, Daisuke Sugiyama, Rika Miki, Yoshihiro Koya, Tomoko Kobayashi, Takafumi Ushida, Yukako Iitani, Noriyuki Nakamura, Taro Owaki, Hiroyoshi Nishikawa, Shinya Toyokuni, Hiroaki Kajiyama, Tomomi Kotani

Life sciences Vol. 308 page： 120955 - 120955 2022.11

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

AIMS: Molecular hydrogen (H2) has attracted growing interest because of its implications in various diseases. However, the molecular mechanisms underlying the remarkable effect of a small amount of H2 remain elusive. No knowledge has been available on the role of H2 in the etiology of pregnancy disorders or its direct influence on human immune cells. Since maternal immunity, T cells in particular, plays a critical role in pregnancy maintenance. We investigated the effects of H2 on T cells and its relation to preterm birth (PTB). MAIN METHODS: Exhaled H2 concentrations in pregnant women were measured and correlated with cytokine concentrations in maternal and umbilical cord blood. H2 was added to T cells collected from healthy donors, and differentiation and proliferation were examined. Energy metabolism was also examined. H2 was administered to mice and cytokine expression was compared. KEY FINDINGS: Our prospective observational study revealed that maternal production of H2 is significantly lower in pregnant women with PTB, suggesting its potential as a biomarker for predicting PTB. We found that H2 has clear associations with several maternal cytokines, and acts as an immunomodulator by exerting mitochondrial function in human T cells. Moreover, in vivo administration of H2 to pregnant mice regulated inflammatory responses and reduced PTB caused by T cell activation, which further supports the notion that H2 may contribute to prolonged gestation through its immunomodulatory effect. SIGNIFICANCE: Measuring maternal H2-production could be a potential clinical tool in the management of PTB, and H2 may have positive impact on pregnancy maintenance.

DOI： 10.1016/j.lfs.2022.120955

Commentary for an article on photooxidation in isolated chloroplasts. Reviewed International journal Open Access

Shinya Toyokuni, Yingyi Kong, Danyang Mi

Archives of biochemistry and biophysics Vol. 726 page： 109133 - 109133 2022.9

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

This commentary concerns a highly cited paper by Robert L Heath and Lester Packer in Archives of Biochemistry and Biophysics published in 1968. Chloroplasts are organelles in algae and plants that use light energy for carbon fixation and oxygen production. These authors discovered that isolated chloroplasts exposed to visible light undergo a cyclic peroxidation of tri-unsaturated fatty acids, contributing to the double-edged sword concept of electron transfer reactions.

DOI： 10.1016/j.abb.2022.109133