Unbiased screening identifies chemically diverse candidate protective agents that reduce Psy toxicities.

<p><b>(A)</b> Schematic depicting the work flow for unbiased screening with Celigo adherent cytometer (Nexcelom). <b>(B)</b> Representative plot of relative cell number over 5 d for rat O-2A/OPCs exposed to 1 μM Psy or vehicle (DMSO). Quantification of the relative proliferation rate for all 1,040 drugs at three concentrations over 5 d. Blue: “hit” drugs selected for further validation. A bar graph quantifying the relative proliferation rate of all vehicle and Psy controls is included. <b>(C)</b> Quantification of the relative proliferation rate of rat O-2A/OPCs exposed to 1.5 μM Psy, with and without verified pro-division “hits,” over 5 d. <b>(D)</b> Quantification as in <b>(C)</b> for cells exposed to Psy 48 h before exposure to the indicated drugs. <b>(E)</b> Summary of clinical metadata for lead “hits” as % of total. (* worldwide approval, including FDA. ** reported blood–brain barrier permeability; not all drugs have been examined/reported.) <b>(F)</b> Quantification of cell survival in cells exposed to 3.3 μM Psy for 5 d, with and without the indicated drugs, for 5 d. <b>(G, H)</b> Quantification of the <b>(G)</b> relative survival and <b>(H)</b> number of rat O-2A/OPCs per clone exposed to of Psy (1 μM in <b>H</b>), with and without 100 ng/mL insulin-like growth factor (IGF-1), for 5 d. <b>(I–K)</b> Quantification of <b>(I)</b> neutral lipid and phospholipid accumulation, <b>(J)</b> cathepsin B and D activities in rat O-2A/OPCs exposed to the indicated drugs, with and without 1 μM Psy, and <b>(K)</b> time to half-maximal intensity for endocytosis of fluorescent nanobeads for <b>(I)</b> 2 d or <b>(J, K)</b> 24 h. <b>(L)</b> Quantification of lysosomal pH for rat O-2A/OPCs exposed to 1 μM Psy, with and without the indicated “hits” (blue) or “non-hits” (gray), for 24 h. NT-3: 10 ng/mL; 1E04: 5 μM; 5F05, 9A06, 9H10: 1 μM. ^a<i>p</i> < 0.05, ^b<i>p</i> < 0.01 versus Psy-only. Data for all graphs displayed as mean ± SEM; <i>ns</i> = not significant; *<i>p</i> < 0.05, **<i>p</i> < 0.01, ^†<i>p</i> < 0.001 versus untreated; ^a<i>p</i> < 0.05, ^b<i>p</i> < 0.01, ^c<i>p</i> < 0.001 versus Psy-only treatment. See also <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002583#pbio.1002583.s003" target="_blank">S2 Fig</a>, <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002583#pbio.1002583.s012" target="_blank">S1</a> and <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002583#pbio.1002583.s013" target="_blank">S2</a> Tables for drug names and concentrations. Data presented in this figure can be found in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002583#pbio.1002583.s001" target="_blank">S1 Data</a>.