Progetto LRRK2-KIN

Leucine-rich repeat kinase 2 (LRRK2) kinase activity is increased in the most common pathogenic mutation and is believed to play a role in Parkinson’s disease (PD) pathobiology. This has stimulated the development of potent and selective LRRK2 kinase inhibitors, making LRRK2 kinase inhibition one of the most prevailing disease-modifying therapeutic PD strategies. Although several lines of evidence support the beneficial effects of LRRK2 kinase inhibitors, many questions need to be answered before clinical applications can be envisaged. We and others have found that besides dephosphorylation, LRRK2 kinase inhibition induces LRRK2 protein destabilization. This finding has implications in the light of therapeutic approaches since it is unclear whether this is a desired or an unwanted effect.

With this project, we aim to provide insight in the molecular and cellular consequences of LRRK2 kinase inhibition. Using different LRRK2 kinase inhibitors and different cell culture conditions we will study how the LRRK2 kinase inhibitor-induced destabilization is regulated and whether and how it is correlated to LRRK2 dephosphorylation in neuronal cells and during microglial activation. In view of clinical applications, the effects of LRRK2 kinase inhibition on LRRK2 stability and phosphorylation will also be examined in cells derived from (LRRK2) PD patients. In addition to the molecular effects on LRRK2, we strive to understand the cellular effects of LRRK2 kinase inhibition in both microglial cells and neurons, given the importance of microglial activation in neuronal cell death in PD. The effects of LRRK2 kinase inhibition on microglial activation and on activated microglial-induced neuronal cell death will therefore be investigated using primary cell (co-)cultures. By combining these results, we will be able to correlate inhibitor-induced cellular and molecular changes related to LRRK2 phosphorylation and protein level.