Metabolite classification through novel metabolomics framework reveals mechanism underlying the therapeutic effects...

Post-stroke depression (PSD) pathophysiology involves glutamate excitotoxicity mediated through 'postsynaptic density protein95-neuronal nitric oxide synthase' (PSD95-nNOS) coupling. However, the therapeutic mechanisms of targeting this complex remain incompletely understood.

To elucidate the antidepressant mechanisms of the PSD95-nNOS decoupler ZL006 using an innovative integrated metabolomics approach.

We developed an innovative integrated metabolomics approach to investigate the antidepressant mechanisms of ZL006, a selective PSD95-nNOS decoupler. Using a rat model of PSD, we employed untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics combined with a novel analytical framework that distinguished treatment efficacy-associated metabolites from drug bias-associated ones. This classification enabled identification of primary drug mechanisms versus secondary responses. Pathway analyses focused on proteins interacting with drug-specific metabolites, with key findings validated through quantitative polymerase chain reaction (qPCR).

ZL006 demonstrated dose-dependent antidepressant effects while modulating multiple neurotransmitter pathways, including tryptophan, tyrosine, and arginine metabolism, along with steroid hormone synthesis. Our integrated metabolomics approach revealed vascular endothelial growth factor (VEGF) signaling, hypoxia-inducible factor (HIF) pathway, and tight junction regulation as primary mechanisms of action.

This novel metabolomics strategy, by discriminating between treatment-associated and compound-intrinsic pathways, provided unprecedented mechanistic insights into ZL006's therapeutic effects. The findings suggest that ZL006 alleviates PSD through coordinated modulation of neuroplasticity, angiogenesis, and stress responses via PSD95-nNOS targeting. This integrated analytical approach presents a valuable framework for mechanistic investigation of therapeutic compounds.