Figure 6.
Regulated secretion of POMC-derived peptides. A) Experimental schematic for quantifying the stimulated secretion of POMC-derived peptides in hPSC-derived hypothalamic neurons by LC-MS/MS. B) Secreted d-α-MSH, β-MSH and β-EP (1-31) peptides in pre-stimulation controls (black circles), 30 mM KCl stimulations (red circles) and ACSF controls (blue circles). Molar peptide concentrations were normalised to the mean pre-stimulation β-MSH concentration. N = 4 independent experiments with 4–8 technical replicates per experiment. C) KCl-induced changes in secreted peptide concentration were calculated from data shown in (B) for each technical replicate by subtracting the pre-stimulation peptide concentrations from the ACSF control or KCl stimulation condition, and normalising to mean concentrations seen in ACSF control-stimulated cultures. KCl stimulation significantly (P < 3 × 10−5) increased the concentrations of d-α-MSH, β-MSH and β-EP (1-31). KCl, potassium chloride. Error bars show SEM. ****, P < .0001.