Preclinical modeling of chronic inhibition of the Parkinson's disease associated kinase LRRK2 reveals altered function of the endolysosomal system in vivo

Mol Neurodegener. 2021 Mar 19;16(1):17. doi: 10.1186/s13024-021-00441-8.


The most common mutation in the Leucine-rich repeat kinase 2 gene (LRRK2), G2019S, causes familial Parkinson's Disease (PD) and renders the encoded protein kinase hyperactive. While targeting LRRK2 activity is currently being tested in clinical trials as a therapeutic avenue for PD, to date, the molecular effects of chronic LRRK2 inhibition have not yet been examined in vivo. We evaluated the utility of newly available phospho-antibodies for Rab substrates and LRRK2 autophosphorylation to examine the pharmacodynamic response to treatment with the potent and specific LRRK2 inhibitor, MLi-2, in brain and peripheral tissue in G2019S LRRK2 knock-in mice. We report higher sensitivity of LRRK2 autophosphorylation to MLi-2 treatment and slower recovery in washout conditions compared to Rab GTPases phosphorylation, and we identify pS106 Rab12 as a robust readout of downstream LRRK2 activity across tissues. The downstream effects of long-term chronic LRRK2 inhibition in vivo were evaluated in G2019S LRRK2 knock-in mice by phospho- and total proteomic analyses following an in-diet administration of MLi-2 for 10 weeks. We observed significant alterations in endolysosomal and trafficking pathways in the kidney that were sensitive to MLi-2 treatment and were validated biochemically. Furthermore, a subtle but distinct biochemical signature affecting mitochondrial proteins was observed in brain tissue in the same animals that, again, was reverted by kinase inhibition. Proteomic analysis in the lung did not detect any major pathway of dysregulation that would be indicative of pulmonary impairment. This is the first study to examine the molecular underpinnings of chronic LRRK2 inhibition in a preclinical in vivo PD model and highlights cellular processes that may be influenced by therapeutic strategies aimed at restoring LRRK2 physiological activity in PD patients.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / drug effects
  • Brain / metabolism
  • Drug Evaluation, Preclinical
  • Endosomes / drug effects*
  • Endosomes / physiology
  • Gain of Function Mutation
  • Gene Knock-In Techniques
  • Humans
  • Indazoles / pharmacology*
  • Kidney / drug effects
  • Kidney / metabolism
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 / antagonists & inhibitors*
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 / genetics
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 / metabolism
  • Lung / drug effects
  • Lung / metabolism
  • Lysosomes / drug effects*
  • Lysosomes / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Mitochondrial Proteins / metabolism
  • Organ Specificity
  • Parkinson Disease / enzymology*
  • Phosphorylation / drug effects
  • Point Mutation
  • Protein Kinase Inhibitors / pharmacology*
  • Protein Processing, Post-Translational / drug effects
  • Proteome / drug effects
  • Pyrimidines / pharmacology*
  • Random Allocation
  • rab GTP-Binding Proteins / metabolism


  • 2,6-dimethyl-4-(6-(5-(1-methylcyclopropoxy)-1H-indazol-3-yl)pyrimidin-4-yl)morpholine
  • Indazoles
  • Mitochondrial Proteins
  • Protein Kinase Inhibitors
  • Proteome
  • Pyrimidines
  • LRRK2 protein, human
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2
  • rab12 protein, mouse
  • rab GTP-Binding Proteins