Fig. 2 | Nature Communications

Fig. 2

From: The anthelmintic praziquantel is a human serotoninergic G-protein-coupled receptor ligand

Fig. 2

(R)-PZQ triggers Ca2+ release via 5-HT2BR. a Representative fluorescence traces from a single experiment where single cells loaded with fluo-4-AM in a HEK293 cell line prior to (top), or after (bottom) 5-HT2BR induction. Traces show fluorescence ratio following addition of indicated ligands (final concentrations (±)-PZQ (75 µM), 5-HT (100 nM) or ACh (100 µM)), or vehicle (DMSO, 0.05%). b Pseudocolored confocal images are displayed from the indicated times (‘1’–‘4’) on associated fluorescence traces as introduced in Fig. 1a. Scalebar, 80 µm. c Peak fluorescence ratio (F/F0, where ‘F’ represents fluorescence at peak and ‘F0‘ represents fluorescence at time = 0) from cumulative Ca2+ imaging after addition of vehicle, (±)-PZQ, 5-HT or ACh in uninduced (open bars) or induced cell lines (solid, hatched bars; n ≥ 3 independent inductions). Serotonergic antagonists (ritanserin (100 nM, final concentration), SB204741 (100 nM), or mesulergine (200 nM) were preincubated with induced cells prior to addition of (±)-PZQ (75 µM), 5-HT (10 nM), or ACh (100 µM). Data represent means ± s.e.m. of peak responses averaged from multiple cells (>20) from n ≥ 3 independent inductions. d Dose-response relationship for (±)-PZQ efficacy in cells induced for 5-HT2BR expression (n = 6 for each concentration). e Confocal Ca2+ imaging assays with (±)-PZQ and resolved enantiomers in uninduced (top row) and 5-HT2BR induced cell lines (bottom three rows). Experiments were performed with racemic PZQ ((±)-PZQ), and individual (S)-PZQ and (R)-PZQ stereoisomers (5 µM, final concentration). Scalebar, 80 µm. f Processed data set from experiments such as shown in e representing population mean ± s.e.m. (>20 cells) from n ≥ 3 independent inductions

Back to article page