The synthetic cannabinoid THJ-2201 modulates mitochondrial activity and enhances mitochondrial recruitment to newly-forming neurites during neurodifferentiation of NG108-15 cells.

Abstract

Synthetic cannabinoids (SCs) have been increasingly associated with neurodevelopmental impairment; however, the underlying mechanisms remain poorly understood. In particular, the impact of SCs on mitochondria during neurodifferentiation remains largely unexplored, despite the central role of these organelles in this process. Building upon our previous findings that THJ-2201, a widely used SC, enhances neurite outgrowth in NG108-15 neuroblastoma-glioma cells at biologically relevant concentrations (1 pM-1 μM), we investigated whether this SC influences mitochondrial function, morphology, and dynamics during neurodifferentiation. THJ-2201 exposure caused a 30-40% reduction in intracellular ATP levels in a CB1-dependent manner, along with a 20-30% decrease in TMRE retention during NG108-15 neurodifferentiation. Cells treated with 1 μM THJ-2201 failed to sustain the expected increase in VDAC levels (an indirect marker of mitochondrial mass) during regular differentiation. Concurrently, THJ-2201 elevated PGC-1α levels, a key regulator of mitochondrial biogenesis, by disrupting its translocation to the nucleus. Expression of both fusion (Opa1, Mfn1, and Mfn2) and fission (Drp1 and Fis1) markers exhibited a less pronounced increase between 24 and 72 h in THJ-2201-treated cells. Mitochondrial morphology exhibited alterations in mean area, perimeter, branching, and circularity in the soma after 72 h exposure. Additionally, THJ-2201 reduced mitochondrial mobility in neurites without affecting their average speed or run length and led to a mitochondrial accumulation within neurites, as indicated by decreased Miro1 expression. Overall, these findings suggest that THJ-2201-induced mitochondrial remodelling and redistribution may transiently enhance local energy supply for neurite outgrowth, but at the expense of somatic mitochondrial function, resulting in an overall bioenergetic imbalance.