9-Methylfascaplysin, a Marine-Derived Bioactive Compound, Promotes Neurite Outgrowth via the Inhibition of ROCK2

Background: The impairment of neurite outgrowth is an early pathological hallmark underlying various neurodegenerative disorders. The promotion of neurite outgrowth was considered as a feasible strategy to treat neurodegenerative disorders. 9-Methylfascaplysin (9-MF), a marine-derived, bioactive compound, has exhibited multiple neuroprotective activities. Methods and Result: In this study, 9-MF at nanomolar concentrations promoted neurite outgrowth, upregulated the expression of growth-associated protein-43 (GAP-43), and increased the mitochondrial positive area with similar efficacy as retinoic acid in PC12 cells. 9-MF-associated differentiated expressed genes were enriched in mitochondria and synapse, forming a Rho-associated coiled-coil containing a protein kinase 2 (ROCK2)-centralized network. CMap analysis further identified positive connections between 9-MF-induced perturbation and perturbations caused by the inhibition of the ROCK2 pathway. Molecular docking analysis demonstrated a high binding affinity between 9-MF and ROCK2, indicating that 9-MF could inhibit ROCK2. Furthermore, 9-MF significantly reduced the phosphorylation of ROCK2 with a similar efficacy as fasudil, a ROCK2 Inhibitor. Narciclasine, a known ROCK2 activator, almost completely abolished the effects of 9-MF on the induction of neurite outgrowth in PC12 cells. Conclusions: 9-MF effectively promoted neurite outgrowth possibly via the inhibition of ROCK2, providing supporting evidence that 9-MF might be developed as a novel neurological drug.