Taken together, our results suggest a potential orchestrated association between an increase in Mmp-7 and Mmp-9/Reck expression ratios in the substantia nigra and a possible positive effect on cognitive performance in subjects affected by PD.
We did not find association between the examined genetic variants of MMP-2, MMP-3, and TIMP-2 and PD susceptibility.This is the first study that demonstrated a protective effect of TIMP-1 rs4898 C allele on male PD and a modest association of MMP-9rs17576 AA genotype with PD susceptibility in the Taiwan population.
Our results show a significant association between the C(-1562)T polymorphism in the MMP-9 gene and risk of PD (odds ratio = 2.268, 95% CI 1.506-3.416, p<0.001) as well as risk of sALS (odds ratio = 2.163, 95% CI 1.233-3.796, p = 0.006), supporting a role for MMP-9 polymorphism in the risk for PD and sALS.
Therefore, controlling MMP-9 expression may have therapeutic potential in Parkinson's disease, which is caused by various neurotoxins, such as 6-OHDA and MPP(+).