[
J Mov Disord,
2010]
Mutations in Leucine-rich repeat kinase 2 (LRRK2) gene are the most common cause of sporadic and familial late onset Parkinson's disease (PD). The G2019S common mutation has been identified about 1% of sporadic cases and 4-7% of familial cases. Over 50 variants have since been identified in LRRK2, and at least 7 of these are confirmed to be pathogenic. In addition to pathogenic mutations, several common polymorphisms in the LRRK2 gene (G2385R and R1628P) have been identified that may explain up to 10% of sporadic PD in Asian populations. LRRK2 is a large complex multidomain protein with 2,527-amino-acid and the molecular weight is 286 kDa. LRRK2 multidomain protein consists of a catalytic core domain, kinase domain and a number of putative protein-protein interaction domains. LRRK2 mutations found in PD families, including the G2019S and I2020T mutations show increased intrinsic kinase activity, when assessed with myelin basic protein as substrate. The modification of LRRK2 GTPase and kinase activity affecting residues in the ROC, COR and mitogen-activated protein kinase kinase kinases domains is believed to lead to neuronal cell death, but the pathways involved remain unclear. A number of in vivo models in C. elegans, D. melanogaster and mice have been developed to study the patho/physiological function of LRRK2. Based on current literature, a toxic gain of function in LRRK2 kinase activity is a possible pathophysiologic mechanism and thus inhibition of kinase activity in experimental models offers a potential therapeutic strategy for LRRK2-linked PD.
[
Int J Mol Sci,
2020]
Parkinson's disease (PD) is the most common movement disorder with motor and nonmotor signs. The current therapeutic regimen for PD is mainly symptomatic as the etio-pathophysiology has not been fully elucidated. A variety of animal models has been generated to study different aspects of the disease for understanding the pathogenesis and therapeutic development. The disease model can be generated through neurotoxin-based or genetic-based approaches in a wide range of animals such as non-human primates (NHP), rodents, zebrafish, <i>Caenorhabditis</i> (<i>C.</i>) <i>elegans</i>, and drosophila. Cellular-based disease model is frequently used because of the ease of manipulation and suitability for large-screen assays. In neurotoxin-induced models, chemicals such as 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), rotenone, and paraquat are used to recapitulate the disease. Genetic manipulation of PD-related genes, such as -Synuclein(SNCA), Leucine-rich repeat kinase 2 (LRRK2), Pten-Induced Kinase 1 (PINK1), Parkin(PRKN), and Protein deglycase (DJ-1) Are used in the transgenic models. An emerging model that combines both genetic- and neurotoxin-based methods has been generated to study the role of the immune system in the pathogenesis of PD. Here, we discuss the advantages and limitations of the different PD models and their utility for different research purposes.