Fig. 3: NPCT facilitates OXPHOS and ATP production in primary hippocampal neurons.

A Volcano plots showing DEGs in NPCT-stimulated primary hippocampal neurons. B GO enrichment analysis of DEGs. Asterisk represents “oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptor”. C KEGG enrichment analysis of DEGs. D The influence of NPCT on intracellular ATP levels in primary hippocampal neurons. Welch’s ANOVA with Dunnett’s T3 post-hoc analyses. Representative result from 3 independent experiments. ***P < 0.001. E–I The influences of NPCT on the activities of mitochondrial respiratory chain complexes I-V in primary hippocampal neurons. One-way ANOVA with Turkey’s post hoc analyses. n = 4 biological replicates. *P < 0.05, **P < 0.01. J Representative OCR of primary hippocampal neurons exposed to 1 nM NPCT for 24 h, determined by the mitochondrial stress test. OCR was measured before and after sequential injections of oligomycin (O), FCCP (F), and rotenone with antimycin A (R/A). n = 3 independent experiments. K–N Basal respiration, proton leak, maximal respiration, and spare capacity% were calculated from (J) as described in the Methods section. Student’s t-test. **P < 0.01. O, P JC-1 staining showing the mitochondrial membrane potential of primary hippocampal neurons stimulated with 1 nM NPCT for 24 h. One-way ANOVA with Turkey’s post hoc analyses. n = 25 fields from 3 biological replicates. All data are presented as mean ± SEM. DEGs differentially expressed genes, OCR oxygen consumption rate, OXPHOS oxidative phosphorylation.