- PROJECT 4: LRRK2 BIOLOGY IN PARKINSON'S DISEASE Parkinson's disease (PD) is a complex neurodegenerative disorder that is both sporadic and familial. Mutations in the leucine-rich repeat kinase 2 (LRRK2) have recently been shown to result in 4% of autosomal dominant familial cases and 1% of sporadic cases worldwide. The clinical and pathological phenotypes of LRRK2 PD patients are similar to classic late-onset PD and LRRK2 knock out animals are resistant to ?- synuclein dopaminergic (DA) neurodegeneration, further emphasizing the potential importance of this gene. This project will address mechanisms of how aberrant kinase activity leads to disease. Our hypothesis is that disease causing LRRK2 GS elicits translational deregulation through pathogenic phosphorylation of s15, leading altered protein expression and neuronal dysfunction and death. Comprehensive understanding of the molecular changes in mRNA translation, the transcriptome and the proteome elicited by LRRK2 GS is required to understand DA vulnerability. There is also an important interaction with ?-synuclein that impacts DA vulnerability but the mechanism is not yet known.
Aim 1 to address the ongoing controversy regarding the importance of the increased kinase activity of LRRK2 GS mutation on DA neuronal viability, LRRK2 GS kinase-dead (LRRK2 GS/DA) mice were made. These mice also provide a model to explore the non-kinase actions of LRRK2 that has been lacking from the field. Behavioral, neuroanatomical and neurochemical changes will be monitored over time. The functional interaction between LRRK2 and ?-synuclein toxicity and transmission will be monitored in LRRK2 KO and transgenic lines to determine loss of LRRK2 function is protective and gain of LRRK2 function is toxic.
Aim 2 will address the new observation that phosphorylated s15 is a pathogenic target of LRRK2 GS, expression of s15 and phospho-s15 will be monitored in transgenic mice and human postmortem tissue. It will be determined if phosphomimetic s15 is sufficient to elicit neurodegeneration and if phosphodeficient s15 can provide protection from LRRK2 GS neurotoxicity in global and spatially restricted models. These studies will confirm in vivo whether s15 is a pathogenic substrate of LRRK2 GS.
Aim 3 will define the specific changes in mRNA translation, the transcriptome and proteome using advanced technologies in genetically engineered mice and human dopaminergic cultures. The use of both mouse and human models allows assessments in the intact brain while investigating acute changes that lead to chronic neurodegeneration in a relevant human system. The unbiased comprehensive datasets will be a valuable resource to all PD investigators. The goal of this project is to identify nodal points in the signal cascade of neurodegeneration that can provide new targets for future development of therapeutic strategies for the treatment of PD.
Gene mutations in LRRK2 are a common cause of familial and some sporadic PD, yet little is known about physiologic as well as the pathologic actions of LRRK2. Our discovery that mutant LRRK2 abnormally phosphorylates ribosomal protein s15 implicates altered RNA translation and protein expression in neurodegeneration. The goals of this project are to understand the role of increased LRRK2 kinase activity and increased phosho-s15 on RNA translation, the transcriptome and proteome in order to identify nodal points of the network of events that may be critical to altering the outcome of neurodegeneration.
|Martin, Ian; Kim, Jungwoo Wren; Dawson, Valina L et al. (2014) LRRK2 pathobiology in Parkinson's disease. J Neurochem 131:554-65|
|Dawson, Ted M; Dawson, Valina L (2014) Parkin plays a role in sporadic Parkinson's disease. Neurodegener Dis 13:69-71|
|Lee, Yun-Il; Giovinazzo, Daniel; Kang, Ho Chul et al. (2014) Protein microarray characterization of the S-nitrosoproteome. Mol Cell Proteomics 13:63-72|
|Siuda, Joanna; Jasinska-Myga, Barbara; Boczarska-Jedynak, Magdalena et al. (2014) Early-onset Parkinson's disease due to PINK1 p.Q456X mutation--clinical and functional study. Parkinsonism Relat Disord 20:1274-8|
|Fatokun, Amos A; Dawson, Valina L; Dawson, Ted M (2014) Parthanatos: mitochondrial-linked mechanisms and therapeutic opportunities. Br J Pharmacol 171:2000-16|
|Stafa, Klodjan; Tsika, Elpida; Moser, Roger et al. (2014) Functional interaction of Parkinson's disease-associated LRRK2 with members of the dynamin GTPase superfamily. Hum Mol Genet 23:2055-77|
|Martin, Ian; Kim, Jungwoo Wren; Lee, Byoung Dae et al. (2014) Ribosomal protein s15 phosphorylation mediates LRRK2 neurodegeneration in Parkinson's disease. Cell 157:472-85|
|Tsika, Elpida; Glauser, Liliane; Moser, Roger et al. (2014) Parkinson's disease-linked mutations in VPS35 induce dopaminergic neurodegeneration. Hum Mol Genet 23:4621-38|
|Pirooznia, Sheila K; Dawson, Valina L; Dawson, Ted M (2014) Motor neuron death in ALS: programmed by astrocytes? Neuron 81:961-3|
|Lasagna-Reeves, Cristian A; Sengupta, Urmi; Castillo-Carranza, Diana et al. (2014) The formation of tau pore-like structures is prevalent and cell specific: possible implications for the disease phenotypes. Acta Neuropathol Commun 2:56|
Showing the most recent 10 out of 141 publications