Molecular beacon probes uncover CB1R dynamics in cerebrospinal fluid during ischemia-induced epilepsy

This study used molecular beacon-modified fluorescent probes (Cy-MB-BHQ) to monitor cannabinoid receptor 1 (CB1R) changes in the cerebrospinal fluid (CSF) of middle cerebral artery occlusion (MCAO) mice and to examine the regulatory roles of CB1R and DEPDC5 in cerebral ischemia-induced epilepsy. A DEPDC5 knockout (KO) mouse model, single-cell omics analysis, an in vitro excitatory-neuron model, CB1R inhibitor intervention, and molecular probe tracking were integrated to evaluate the DEPDC5/mechanistic target of rapamycin (mTOR) signaling axis. DEPDC5 KO aggravated post-ischemic epileptic seizures and was accompanied by enhanced mTOR pathway activation. JD-5037 treatment upregulated DEPDC5 and inhibited mTOR signaling in wild-type (WT)+MCAO mice, whereas this protective effect was weakened in the DEPDC5 KO background. Cy-MB-BHQ application further showed dynamic CB1R changes during ischemia-induced epilepsy, which may be functionally associated with abnormal regulation of the DEPDC5/mTOR signaling axis. These findings support the involvement of the CB1R/DEPDC5/mTOR axis in post-ischemic epileptogenesis and demonstrate the feasibility of molecular beacon probes for monitoring CB1R-associated signals in CSF.