Fig. 3

Treatment targeting LRRK2 kinase and GCase activities in PD. a In LRRK2-PD, LRRK2 kinase activity is increased and GCase activity is reduced. Treatment with LRRK2 kinase inhibitor has been shown to improve GCase activity, normalize lysosome function and reduce α-syn. b In GBA-PD, GCase activity is reduced while LRRK2 kinase activity is normal. Both ambroxol and LRRK2 kinase inhibitor have been shown to improve GCase activity, lysosomal function and reduce α-syn. c Idiopathic PD has been shown to have increased LRRK2 kinase and reduced GCase activities; it remains to be seen whether treatment with ambroxol or LRRK2 kinase inhibitor will be useful