Investigating the Protective Effects of a Citrus Flavonoid on the Retardation Morphogenesis of the Oligodendroglia-like Cell Line by Rnd2 Knockdown

Shoya Fukatsu; Yuki Miyamoto; Yu Oka; Maki Ishibashi; Remina Shirai; Yuki Ishida; Shin Endo; Hironori Katoh; Junji Yamauchi

doi:10.3390/neurolint16010003

Investigating the Protective Effects of a Citrus Flavonoid on the Retardation Morphogenesis of the Oligodendroglia-like Cell Line by Rnd2 Knockdown

Neurol Int. 2023 Dec 26;16(1):33-61. doi: 10.3390/neurolint16010003.

Authors

Shoya Fukatsu¹, Yuki Miyamoto^{1

2}, Yu Oka³, Maki Ishibashi³, Remina Shirai¹, Yuki Ishida³, Shin Endo³, Hironori Katoh⁴, Junji Yamauchi^{1

2

5}

Affiliations

¹ Laboratory of Molecular Neurology, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.
² Laboratory of Molecular Pharmacology, National Research Institute for Child Health and Development, Setagaya-ku, Tokyo 157-8535, Japan.
³ Personal Health Care Division, Hayashibara Co., Ltd., Okayama 702-8006, Japan.
⁴ Department of Biological Chemistry, Graduate School of Science, Osaka Metropolitan University, Osaka 599-8531, Japan.
⁵ Diabetic Neuropathy Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan.

Abstract

Recent discoveries suggest links between abnormalities in cell morphogenesis in the brain and the functional deficiency of molecules controlling signal transduction in glial cells such as oligodendroglia. Rnd2 is one such molecule and one of the Rho family monomeric GTP-binding proteins. Despite the currently known functions of Rnd2, its precise roles as it relates to cell morphogenesis and disease state remain to be elucidated. First, we showed that signaling through the loss of function of the rnd2 gene affected the regulation of oligodendroglial cell-like morphological differentiation using the FBD-102b cell line, which is often utilized as a differentiation model. The knockdown of Rnd2 using the clustered regularly interspaced palindromic repeats (CRISPR)/CasRx system or RNA interference was shown to slow morphological differentiation. Second, the knockdown of Prag1 or Fyn kinase, a signaling molecule acting downstream of Rnd2, slowed differentiation. Rnd2 or Prag1 knockdown also decreased Fyn phosphorylation, which is critical for its activation and for oligodendroglial cell differentiation and myelination. Of note, hesperetin, a citrus flavonoid with protective effects on oligodendroglial cells and neurons, can recover differentiation states induced by the knockdown of Rnd2/Prag1/Fyn. Here, we showed that signaling through Rnd2/Prag1/Fyn is involved in the regulation of oligodendroglial cell-like morphological differentiation. The effects of knocking down the signaling cascade molecule can be recovered by hesperetin, highlighting an important molecular structure involved in morphological differentiation.

Keywords: RNA; cell line; clustered regularly interspaced short palindromic repeats; disease; flavonoid; monomeric GTP-binding proteins; morphogenesis; oligodendroglia; phosphotransferases; signal transduction; small interfering.

Grants and funding

This work was supported by Grants-in-Aid for Scientific Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Grants-in-Aid for Medical Scientific Research from the Japanese Ministry of Health, Labor and Welfare (MHLW). This work was also supported by the Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), the Daiichi Sankyo Foundation, the Japanese Foundation for Pediatric Research, the Mishima Kaiun Memorial Foundation, the Mitsubishi Tanabe Foundation, the Otsuka Foundation, and the Takeda Science Foundation.