Tokushima University / Educator and Researcher Directory --- Yanai, Ryoji

Personal Web Page

https://researchmap.jp/7000023507 (researchmap)

https://orcid.org/0000-0002-0265-9760 (ORCID)

Field of Study

○	Life sciences [Ophthalmology]

Subject of Study

Book / Paper

(See https://researchmap.jp/7000023507 (researchmap) for Published Book / Papers / Presentations.)

Academic Paper (Judged Full Paper):

1.	Ryoji Yanai, Sora Mizukami, Akihiko Sakamoto, Kenji Takemoto, Tetsuya Seto, Kazuya Uehara, Kiminori Yukata, Takashi Sakai, Keiko Iwaisako, Norihiko Takeda, Ryoji Yanai and Masataka Asagiri : Cell cycle checkpoint factor p15Ink4b is a novel regulator of osteoclast differentiation., Scientific reports, 15, 1, 2025. (Summary) Osteoclasts are specialized cells essential for bone resorption, a crucial process in bone remodeling, and dysregulation of osteoclastogenesis can lead to pathological bone loss such as osteoporosis and rheumatoid arthritis. Therefore, understanding the precise mechanisms governing osteoclast differentiation is crucial for developing effective therapies for skeletal diseases. In osteoclastogenesis, as well as other differentiated cells, it is well understood that cell cycle arrest is essential for terminal differentiation and is tightly regulated by CDK inhibitors such as Cip/Kip family and Ink4 family protein. In this manuscript, we identified p15Ink4b, a member of the Ink4 family, as a novel regulator of osteoclastogenesis by comprehensive single-cell RNA sequence data reanalyzing. Furthermore, histological analysis and in vitro osteoclast differentiation assay revealed that p15Ink4b functionally regulates osteoclastogenesis. Our findings may not only provide insights into the molecular mechanisms of osteoclast differentiation but also underscore the potential of harnessing cell cycle mechanisms to develop novel therapeutic strategies for bone diseases. (Keyword) Osteoclasts / Cell Differentiation / Animals / Mice / Osteogenesis / Cyclin-Dependent Kinase Inhibitor p15 / Cell Cycle Checkpoints / Humans / Mice, Inbred C57BL (Link to Publication Site) ● Publication site (DOI): 10.1038/s41598-025-89988-w (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 39979342 ● Search Scopus @ Elsevier (PMID): 39979342 ● Search Scopus @ Elsevier (DOI): 10.1038/s41598-025-89988-w (DOI: 10.1038/s41598-025-89988-w, PubMed: 39979342)
2.	Tetsuya Seto, Kiminori Yukata, Shunya Tsuji, Yusuke Takeshima, Takeshi Honda, Akihiko Sakamoto, Kenji Takemoto, Hiroki Sakai, Mayu Matsuo, Yurika Sasaki, Mizuki Kaneda, Mikako Yoshimura, Atsushi Mihara, Kazuya Uehara, Aira Matsugaki, Takayoshi Nakano, Koji Harada, Yoshiro Tahara, Keiko Iwaisako, Ryoji Yanai, Norihiko Takeda, Takashi Sakai and Masataka Asagiri : Methylglyoxal compromises callus mineralization and impairs fracture healing through suppression of osteoblast terminal differentiation., Biochemical and biophysical research communications, 747, 2025. (Summary) Impaired fracture healing in diabetic patients leads to prolonged morbidity and increased healthcare costs. Methylglyoxal (MG), a reactive metabolite elevated in diabetes, is implicated in various complications, but its direct impact on bone healing remains unclear. Here, using a non-diabetic murine tibial fracture model, we demonstrate that MG directly impairs fracture healing. Micro-computed tomography revealed decreased volumetric bone mineral density in the callus, while callus volume remained unchanged, resulting in a brittle bone structure. This was accompanied by reduced expression of osteocalcin and bone sialoprotein, both critical for mineralization. Biomechanical analysis indicated that MG reduced the mechanical resilience of the fracture site without altering its elastic strength, suggesting that the impairment was not primarily due to the accumulation of advanced glycation end-products in the bone extracellular matrix. In vitro studies confirmed that non-cytotoxic concentrations of MG inhibited osteoblast maturation and mineralization. Transcriptomic analysis identified downregulation of Osterix, a key transcription factor for osteoblast maturation, without altering Runx2 levels, leading to decreased expression of key mineralization-related factors like osteocalcin. These findings align with clinical observations of reduced circulating osteocalcin levels in diabetic patients, suggesting that the detrimental effects of MG on osteoblasts may extend beyond bone metabolism. Our study highlights MG and MG-sensitive pathways as potential therapeutic targets for improving bone repair in individuals with diabetes and other conditions characterized by elevated MG levels. (Keyword) Animals / Pyruvaldehyde / Fracture Healing / Osteoblasts / Cell Differentiation / Calcification, Physiologic / Mice / Bony Callus / Mice, Inbred C57BL / Osteocalcin / Male / Sp7 Transcription Factor (Link to Publication Site) ● Publication site (DOI): 10.1016/j.bbrc.2025.151312 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 39799866 ● Search Scopus @ Elsevier (PMID): 39799866 ● Search Scopus @ Elsevier (DOI): 10.1016/j.bbrc.2025.151312 (DOI: 10.1016/j.bbrc.2025.151312, PubMed: 39799866)

Proceeding of International Conference:

1.	Ryoji Yanai and Yoshinori Mitamura : The influence of thick-type conventional soft contact lenses YOUSOFT ®, developing for the astigmatism correction on a rabbit corneal epithelium, ARVO2025, Apr. 2025.
2.	Ryoji Yanai, 三﨑裕子, Mariko Egawa, Masayuki Yamada and Yoshinori Mitamura : Two cases of Tatto-associated granulomatous uveitis, INFLAMMATIO 2024, Nov. 2024.
3.	Ryoji Yanai and Yoshinori Mitamura : The effects of the thick type of YOUSOFT contact lenses for aphakic hyperopia on a rabbit corneal epithelium, ISCLR Symposium, Aug. 2024.

Proceeding of Domestic Conference:

1.	Ryoji Yanai, 安永玄太, 辻竣也, 本田健, 岩田在博, 宮川英二, 吉田幸治, 岸本充弘, 酒井大樹, 藤瀬良弘, 朝霧成拳 and Yoshinori Mitamura : オメガ3脂肪酸を含有した鯨油摂取によるマウス脈絡膜新生血管の抑制効果, 第129回日本眼科学会総会, Apr. 2025.
2.	Yoshinori Mitamura, MIki Akiko, Terasaki Hiroto, Chuji Shinichiro, sakaeda Yukinori, Seki Kyousuke, Ishigooka Gaku, Iwase Takeshi, Ohara Hiromi, Tsujinaka Hiroki, Fukuyama Hisashi, Abe yuuki and Ryoji Yanai : Six-month outcomes of faricimab treatment fou neovascular age-related macular degeneration, FujiRetina2025, Mar. 2025.
3.	Ryoji Yanai, Yasunaga Genta, Tsuji Shunya, Honda Takeshi, Iwata Arihiro, Miyagawa Eiji, Yoshida Koji, Kishimoto Mitsuhiro, Sakai Hiroki, Fujise Yoshihiro, Asagiri Masataka and Yoshinori Mitamura : Dietary intake of whale oil-containing ω-3 long-chain polyunsaturated fatty acids attenuates choroidal neovascularization in mice, FujiRetina2025, Mar. 2025.
4.	Ryoji Yanai and Yoshinori Mitamura : 強度乱視用高含水ソフトコンタクトレンズによる家兎角膜への安全性, 角膜カンファランス2025, Feb. 2025.
5.	三﨑裕子, Ryoji Yanai, Mariko Egawa, Masayuki Yamada and Yoshinori Mitamura : Tattoo関連肉芽腫性ぶどう膜炎の2例, 第78回日本臨床眼科学会, Nov. 2024.
6.	Ryoji Yanai, 三﨑裕子, Masayuki Yamada, Mariko Egawa and Yoshinori Mitamura : Tattoo関連肉芽腫性ぶどう膜炎の2例, 第52回日本臨床免疫学学会総会, Oct. 2024.

Et cetera, Workshop:

1.	Ryoji Yanai, Naoki Inomoto, 谷彰浩, Masayuki Yamada, Mariko Egawa and Yoshinori Mitamura : 徳島大学病院における自己免疫網膜症診断に対する診断と治療, 第84回徳島眼科集談会, Dec. 2024.

Grants-in-Aid for Scientific Research (KAKEN Grants Database @ NII.ac.jp)

鯨油由来の脂肪酸成分による免疫細胞誘導療法を目指した眼炎症抑制療法の開発 (Project/Area Number: 24K12808 )
破骨細胞の新たな調節メカニズム：炎症と細胞外マトリクスの相互作用の解明 (Project/Area Number: 24K12310 )
眼炎症疾患の患者を中心とした診療連携におけるぶどう膜炎診療システムの有用性 (Project/Area Number: 23K01903 )
Ocular gateway reflex, which is mediated by sensory nerve, and relapsing control by neurotransmitter (Project/Area Number: 21K09743 )
Development of new treatment for age related macular degeneration focused on blood retinal barrier independent with VEGF (Project/Area Number: 18K09449 )
The involvement of potentially allergic inflammation to fibrosis in conjunctival tissue (Project/Area Number: 15K10870 )
Elucidation of a destruction mechanism and development of new treatment on intraocular chronic inflammatory diseases with CYP metabolites (Project/Area Number: 15K10869 )
Detectino of AGEs in the basement membrane in the eye, and establishment of the AGE detection clinical equipments. (Project/Area Number: 26670755 )
Retinal regeneration due to regulation of natural immunity (Project/Area Number: 26293373 )
環境酸素濃度の低下による角膜上皮バリアー機能の低下に対する修復機構の解明 (Project/Area Number: 22791663 )
Investigation of ambient oxygen concentration on cell proliferation, cell death, and cell function in corneal cells (Project/Area Number: 20791256 )
Role of neural guidance factor on cornal epithelial wound healing. (Project/Area Number: 20592045 )
Search by Researcher Number (10346554)

Associate Professor : Yanai, Ryoji

Research

Personal Web Page

Field of Study

Subject of Study

Book / Paper

Academic Paper (Judged Full Paper):

Proceeding of International Conference:

Proceeding of Domestic Conference:

Et cetera, Workshop:

Grants-in-Aid for Scientific Research (KAKEN Grants Database @ NII.ac.jp)