Multitarget intervention of Fasudil in the neuroprotection of dopaminergic neurons in MPTP-mouse model of Parkinson's disease

Recent studies have demonstrated that activation of the Rho-associated kinase (ROCK) pathway participates in the dopaminergic neuron degeneration and possibly in Parkinson's disease (PD). In the current study, we tried to observe the therapeutic potential of ROCK inhibitor Fasudil against dopaminergic neuron injury in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-mouse model of PD, and explore possible molecular mechanisms by enzyme-linked immunosorbent assay (ELISA), western blot and immunofluorescent assays. The results showed that MPTP-PD mice presented motor deficits, dopaminergic neuron loss, activation of inflammatory response and oxidative stress as well as ROCK and glycogen synthase kinase 3β (GSK-3β) signaling pathways. The administration of Fasudil exhibited neuroprotective effects against the dopaminergic neurons and improved the motor function recovery in the MPTP-PD mice, accompanied by the suppression of inflammatory responses (IL-1β, TNF-α, NF-κB-p65 and TLR-2), and oxidative stress (iNOS and gp91Phox), which might be associated with the inhibition of ROCK and GSK-3β activity. Simultaneously, the administration of Fasudil resulted in the shift from inflammatory M1 to anti-inflammatory/neurorepair M2 microglia. Additionally, Fasudil intervention enhanced the expression of anti-oxidative factors such as NF-E2-related factor 2 (Nrf2), Hmox as well as neurotrophic factor including GDNF. Our observations defined the neuroprotective effects of Fasudil in MPTP-PD mice, and we found a series of novel effector molecules and pathways for explaining the neuroprotective effects against dopaminergic neurons. However, a lot of investigations are warranted to further elucidate the crosstalk among Fasudil, oxidative stress, inflammatory response, GDNF and ROCK/NF-kB/Nrf2 pathways in the therapeutic potential of PD.