4-MEC potentially triggers CAV1 via the BDNF-TrkB signaling pathway

4-Methylethcathinone (4-MEC), a synthetic cathinone with psychostimulant properties, is increasingly abused as a "designer drug". However, its molecular mechanisms, particularly those related to neuroplasticity regulation, remain poorly understood. Caveolin-1 (CAV1) is a scaffolding protein of membrane lipid rafts and has been confirmed to organize multiple synaptic signaling proteins to regulate synaptic signaling and neuroplasticity. Herein, we investigated whether CAV1 modulates 4-MEC-induced alterations in the BDNF-TrkB signal pathway and neuroplasticity markers in human SH-SY5Y neuroblastoma cells and a mouse-conditioned place preference (CPP) model. Using qRT-PCR and Western blotting, we demonstrated that 4-MEC significantly upregulated CAV1 mRNA and protein levels, as well as components of the BDNF-TrkB signaling pathway and neuroplasticity markers (GAP43, MAP2, SYP). siRNA-mediated CAV1 knockdown abolished 4-MEC-induced increases in these proteins and neuroplasticity-related mRNAs, whereas CAV1 overexpression potentiated these effects. Additionally, molecular docking predicted potential binding sites between 4-MEC and CAV1. Meanwhile, protein docking also predicted the potential binding sites between CAV1 and TrkB, and co-immunoprecipitation confirmed their physical interactions in SH-SY5Y cells. In the mice exposed to 4-MEC in the CPP paradigm, we observed similar upregulation of CAV1, BDNF-TrkB signaling pathway components, and neuroplasticity markers in the brain. These findings identify CAV1 as a potential critical mediator of 4-MEC's neuroadaptive effects through the BDNF-TrkB signal pathway to regulate neuroplasticity. It suggests a possible novel molecular target for synthetic cathinone toxicity, with potential implications for forensic research.