A novel tool for suspension culture of human induced pluripotent stem cells: Lysophospholipids as a cell aggregation regulator

Masato Ibuki; Ikki Horiguchi; Yasuyuki Sakai

doi:10.1016/j.reth.2019.03.008

A novel tool for suspension culture of human induced pluripotent stem cells: Lysophospholipids as a cell aggregation regulator

Regen Ther. 2019 Apr 25:12:74-82. doi: 10.1016/j.reth.2019.03.008. eCollection 2019 Dec 15.

Authors

Masato Ibuki¹, Ikki Horiguchi², Yasuyuki Sakai³

Affiliations

¹ Regenerative Medicine and Cell Therapy Laboratories, Kaneka Corporation, 6-7-3, Minatojima Minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.
² Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka, 565-0871, Japan.
³ Department of Chemical System Engineering, School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.

Abstract

Suspension culture for the increase in human induced pluripotent stem cells (hiPSCs) has been one of the major challenges. Previously, we reported that albumin-associated lipids prevented aggregation of hiPSCs, whereas, lipids responsible for this function were unclear. Here, by using cell aggregation assay, we investigated principal lipids regulated aggregation size of hiPSCs. As a result, lysophosphatidic acid (LPA) and Sphingosine-1-phosphate (S1P), known as lysophospholipids acting as a signaling molecule, were identified. These lipids regulated the aggregation size in a dose-dependent manner. Aggregates formed with these lipids kept the high-expression rates of pluripotent marker genes and had the abilities of proliferation. These studies demonstrated that LPA and S1P were useful for suspension culture for hiPSCs without affecting the growth ability and pluripotency of hiPSCs. This knowledge will lead to the development of a simple and robust method for the mass culture of hiPSCs.

Keywords: Aggregation; Lysophospholipid; Pluripotent stem cells; Spheroid; Suspension culture.