Fig. 1: Identification of LPA as the major cilia disassembly factor in serum.

a Diagram indicates the timing of serum starvation (cilia assembly) and re-stimulation (cilia disassembly). b Serum induces cilia disassembly in a dose-dependent manner. Human retinal pigment epithelial (RPE-1) cells were starved in DMEM/F12 for 48 h to induce cilia formation, and then ciliated RPE-1 cells were re-stimulated with indicated concentrations of FBS for 24 h to induce cilia disassembly. c Lipids are responsible for serum-induced cilia disassembly. Ciliated RPE-1 cells (serum-starved) were stimulated with 1% boiled, pronase-pretreated, turbonuclease-pretreated or lipid-depleted serum for 24 h, respectively. d Lysophosphatidic acid (LPA) induces cilia disassembly. Ciliated RPE-1 cells (serum-starved) were stimulated with 100 μM of various phospholipids for 24 h. Full name of lipids used are shown in “Methods.” e Dose-dependent effects of LPA on cilia disassembly. Ciliated RPE-1 cells (serum-starved) were treated with different concentrations of LPA for 24 h. f Representative images of RPE-1 cells in (e). Cells were stained with anti-Ac-tubulin (green) and anti-γ-tubulin (red) antibodies. Scale bar, 5 μm (main image) and 1 μm (magnified region). Three experiments were repeated independently with similar results. g LPA treatment (2 μM for 24 h) induces cilia disassembly in primary MEF and IMCD3 cells. Source data are provided as a Source Data file. Data are presented as mean ± S.D. of three independent experiments in (b–e) and (g). n, number of cells. ***P < 0.001. One-way ANOVA test was performed followed by Dunnett’s multiple comparisons in b–e; two-way ANOVA test was performed in followed by Dunnett’s multiple comparisons in g.