The Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of California, Los Angeles

Director: Marie-Françoise S. Chesselet, M.D.

Website: http://www.bri.ucla.edu/bri_research/Udall.asp

Central Theme

Over the past year, the UCLA Morris K Udall Parkinson Disease Center of Excellence has continued its focus on the progression of dysfunction, with an emphasis on extra-nigral pathology both in the brain and peripheral organs. The goal of the five distinct yet related projects comprising the UCLA Udall Center is to elucidate, in genetic models of PD and in patients, mechanisms of cellular dysfunction that could be used for therapeutic intervention at early stages of Parkinson’s disease.

 

Recent Significant Advances

Project 1 - Progression of behavioral and pathological deficits preceding dopamine cell death in mouse models of PD (Chesselet and Yang)

The goal of this project is to establish the time course of both motor and non-motor behavioral deficits in genetic mouse models of PD, as well as to create novel genetic models of the disease.  During the past year, we have completed the characterization of olfactory deficits in the Thy1-α-synuclein mice, which have provided us with the means to evaluate the potential therapeutic effects of three novel compounds in collaboration with various biotech companies. Furthermore, we are using these mutant animals to study cardiovascular, digestive, cognitive, and emotional deficits, frequently observed in PD patients, even before the onset of the classical motor symptoms.  In parallel, we have completed a detailed description of the distribution of proteinase K-resistant aggregates of α-synuclein and loss of tyrosine hydroxylase positive terminals in the Thy1-α-synuclein mice, establishing further evidence for their utility as a model of PD. In addition, quantitative PCR validation of transcriptome changes in dopaminergic neurons in substantia nigra isolated by laser capture microdissection have identified a number of genes putatively involved in neuroprotective mechanisms as a response to α-synuclein overexpression.   Two additional new lines of transgenic mice have also been created, and are being characterized (DAT-BAC Parkin-Q311X mutant, and BAC α-synuclein mutant).

Project 2 - Progression of neurotransmitter release dysregulation in mouse and cell models of PD (Maidment and Schweizer)

The overall goal of this project is to examine alterations in dopamine homeostasis in a number of genetic modifications that model PD in the mouse, and to determine whether other neurotransmitter systems, in particular NE and glutamate, are affected. Previous work had shown elevated extracellular dopamine levels in the Thy1-α-synuclein mice and the Parkin exon 3 knockout mice, but not in the DJ-1 KO or in Parkin exon 2 KO mice.  We have extended these studies to include the Parkin Q311X generated at the Center, and have found significant reduction in striatal tissue content of dopamine and DOPAC content in older mice, consistent with behavioral and anatomical changes described in these mice in project 1. Furthermore, we have begun to examine NE content in the Thy-1-α-synuclein mice, based on pathological studies suggesting that the degeneration of NE-containing neurons may precede that of dopaminergic neurons.  Our experiments have also been expanded to extracellular measurements of glutamate in these mice, based on electrophysiological observations (obtained in project 3), which point to a disruption of D-2 receptor mediated regulation of glutamate release, possibly as a consequence of chronic elevation of extracellular dopamine. This project also aims to determine whether the observed dopamine elevation is due to increased release or a deficit in packaging of dopamine into vesicles, and their reverse transport from an elevated cytoplasmic pool. We are also using a lentiviral VMAT2 (vesicular monoamine transporter-2) expression vector to answer the issue of cytosolic vs extracellular dopamine toxicity in vivo and in culture. In other experiments, we are examining the possible roles of Parkin and α-synuclein in regulating presynaptic vesicle recycling, based on observations in project 3. In related studies, we have obtained data in cultured neurons and brain slices, characterizing the role of the ubiquitin-proteasome pathway on synaptic transmission.

Project 3 - Progression of electrophysiological alterations in mouse models of PD (Levine)

This project examines the electrophysiological alterations caused by genetic alterations in a number of different mouse models of PD, in the striatum, cortex and substantia nigra pars compacta dopaminergic neurons. Electrophysiological evidence for pre- and/or postsynaptic dysfunction are obtained in brain slices and acutely isolated neurons from the same line of mutant mice examined in projects 1 and 2. To date, we have shown that the α-synuclein overexpressing mice show early alterations in corticostriatal synaptic function, progressively affecting dopamine modulation. These data provide further evidence for early synaptic alterations in a pre-manifest model of PD. We also examined the modulation of synaptic plasticity in the α-synuclein overexpressing mice, and found alterations in presynaptic plasticity in the corticostriatal pathways, possibly reflecting a reduction in glutamate at these synapses due to modulation of adenylyl cyclase signaling pathways, which may recapitulate an early stage in PD during which over-expressed alpha synuclein dampens corticostriatal synaptic transmission and reduces movement.  Other studies have suggested a role for glutathione, a major cellular antioxidant, which is severely reduced in the substantia nigra of PD postpartum brains, and our experiments have shown that indeed there is a reduction of total glutathione in the corticostriatum of the α-synuclein mutant mice.

Project 4 - Parkin binders in progression of cellular dysfunction and cell death (Schweizer):

This project explores the interactions of parkin with key synaptic proteins in cellular models of PD, and determines how specific mutations in the parkin gene affect its binding properties and its interactions with proteins known to be involved in crucial cellular functions. Specifically, we determined that parkin and synaptotagmin I indeed interact, most likely through the RING motif. Since parkin has activity as an E3-ligase, we have also tested the effects of proteasome inhibition on synaptic function in primary neuronal cultures, which have shown a rapid, activity dependent increase in the recycling pool of synaptic vesicles, while cultures from parkin heterozygote animals do not show this proteasomal regulation of vesicle pools.

Project 5 - Progression of PD and PD co-morbidities; determinants and health-related quality of life outcomes (Vickrey and Ritz):

The aim of this project is to determine the time course and the environmental, behavioral, social, and genetic determinants of progression of motor and non-motor manifestations of PD, and subsequent impact on health-related quality of life (HRQOL). This study of disease progression builds upon the largest cohort of newly diagnosed PD patients identified through the Parkinson’s, Environment, and Genes (PEG) study conducted at UCLA.  We are in the process of recruiting, enrolling, and collecting data from nearly 300 PD patients and controls, to assess whether and to what extent the development and rate of progression of motor and non-motor manifestations (eg, cognitive impairment and depression) are influenced by environmental, behavioral, and social factors, including pesticide exposure, physical activity, stress, coping, and social support. We are also in the process of developing a much-needed, state-of-the-science, dynamic HRQOL item bank that aims to better evaluate the progression of disease and incorporating the many non-motor factors affecting the patients’ quality of life. 

To date, we have conducted over 200 neuropsychiatric assessments, 100 followup interviews, and have begun a second round of in-person interviews and data collections.

Training and Educational Activities

The administrative core of the Center continues to support the educational and training goals of the Center. Center investigators meet weekly to discuss ongoing projects and ideas; once a month these meetings also include key personnel. All PD researchers are invited to the monthly seminars to hear a formal presentation by a member of the group. This year’s half-day UCLA Udall Center Symposium and poster session also drew over 80 attendees and focused on the progress of the Center projects.

During the past year, we have also introduced a special seminar series designed specifically for undergraduate students conducting research in the Center laboratories. Through a six-part seminar series during the academic year and summer session, PI’s at the Center present their work to the undergraduates in an informal setting to promote interaction and discussions.

 

Available Resources

PD Mouse Repository

The mouse genetics core at the UCLA Udall Center is responsible for developing new mouse models of PD, as well as managing and maintaining the existing mutant lines used by Center investigators.  Newly created models are made available to the scientific community after publication as per NIH guidelines and with standard Material Transfer Agreement. The core is also a NINDS/UCLA Repository for Parkinson’s disease Mouse Models provided by other investigators. An updated list of mice available to the scientific community, as well as the procedures for obtaining them are available at http://www.ninds.nih.gov/research/parkinsonsweb/amr/amr_mice_ucla_repository.htm

 

Plans for the Coming Year

Project 1: we shall continue the characterization of olfactory, cognitive, digestive, cardiovascular, and emotional deficits in the Thy1-α-synuclein mice, and continue to work with biotech companies in the testing of potential therapeutics using the expertise developed in the Center. The behavioral and anatomical characterization of the newly created mutant mouse models will be carried on, as well as our studies of alterations in the expression of genes that are potentially involved in neuroprotection and degeneration.

Project 2: we will continue to examine the extracellular dopamine, glutamate, and NE levels in a number of mice with various genetic mutations, at several various time points. We will also extend our measurements to include dopamine metabolites and derivatives reflective of oxidative stress, and use microdialysis, stereological analyses, brain slices, and neuronal cultures of normal and mutant mice to further dissect the role of vesicular transport, recycling, and release in dopamine toxicity.  We will also further examine the effect of α-synuclein overexpression on synaptic function, and its possible regulation by the ubiquitin-proteasome system.

Project 3: we will continue our investigation of the role of glutathione by using gene expression assays and measurements of protein levels and activities of enzymes involved in glutathione synthesis, further exploring the potential link between reduced glutathione levels and altered presynaptic plasticity in the corticostriatum of α-synuclein mutant mice. We will also extend these studies to DJ-1, using knockout mice to examine its involvement in striatal synaptic communication and how it is affected by dopaminergic drugs and aging, as well as the double α-synuclein overexpressing mice, which display age-related motor deficits and dopamine reduction. 

Project 4: through in vitro manipulations of intracellular levels of parkin protein and its interactors, we will continue to assess the role of these proteins in neurotransmitter release, metabolism, vesicle recycling, and ultimately, cellular dysfunction and death.

Project 5: we will continue to collect data through interviews and assessments, and enter all the data into our electronic database. We expect a wealth of information about the progression of PD as well as influencing factors once data collection and analysis is completed.

 

Select Recent Publications

Richter F, Meurers BH, Zhu C, Medvedeva VP, Chesselet MF. Neurons express hemoglobin alpha- and beta-chains in rat and human brains. J Comp Neurology(2009) Aug 10; 515(5):538-47. PMID 19479992

Lu XH, Fleming SM, Meurers B, Ackerson LC, Mortazavi F, Lo V, Hernandez D, Sulzer D, Jackson GR, Maidment NT, Chesselet MF, Yang XW.Bacterial artificial chromosome transgenic mice expressing a truncated mutant parkin exhibit age-dependent hypokinetic motor deficits, dopaminergic neuron degeneration, and accumulation of proteinase K-resistant alpha-synuclein. J Neurosci. 2009 Feb 18;29(7):1962-76. PMID 19228951

Hoang T, Choi DK, Nagai M, Wu DC, Nagata T, Prou D, Wilson GL, Vila M, Jackson-Lewis V, Dawson VL, Dawson TM, Chesselet MF, Przedborski S. Neuronal NOS and cyclooxygenase-2 contribute to DNA damage in a mouse model of Parkinson's disease. Free Radic Biol Med. 2009 Jul 16. PMID 19616617

Watson JB, Hatami A, David H, Masliah E, Roberts K, Evans CE and Levine MS (2009) Alterations in corticostriatal synaptic plasticity in mice overexpressing human alpha-synuclein. Neuroscience :501-13 PMID 19361478

Simon AF, Daniels R, Romero-Calderón R, Grygoruk A, Chang HY, Najibi R, Shamouelian D, Salazar E, Solomon M, Ackerson LC, Maidment NT, Diantonio A and Krantz DE (2009) Drosophila vesicular monoamine transporter mutants can adapt to reduced or eliminated vesicular stores of dopamine and serotonin. Genetics :525-41 PMID 19033154

Rhodes SL and Ritz B (2009) Genetics of iron regulation and the possible role of iron in Parkinson's disease. Neurobiol Dis :183-95 PMID 18675357

Costello S, Cockburn M, Bronstein J, Zhang X and Ritz B (2009) Parkinson's disease and residential exposure to maneb and paraquat from agricultural applications in the central valley of California. Am J Epidemiol :919-26 PMID 19270050

Meurers BH, Zhu C, Fernagut PO, Richter F, Hsia YC, Fleming SM, Oh M, Elashoff D, Dicarlo CD, Seaman RL and Chesselet MF (2009) Low dose rotenone treatment causes selective transcriptional activation of cell death related pathways in dopaminergic neurons in vivo. Neurobiol Dis :182-92 PMID 19013527

Chou AP, Maidment N, Klintenberg R, Casida JE, Li S, Fitzmaurice AG, Fernagut PO, Mortazavi F, Chesselet MF and Bronstein JM (2009) Ziram causes dopaminergic cell damage by inhibiting E1 ligase of the proteasome. J Biol Chem :34696-703                PMID 18818210

Rugbjerg K, Ritz B, Korbo L, Martinussen N and Olsen JH (2009) Risk of Parkinson's disease after hospital contact for head injury: population based case-control study. BMJ :a2494  PMID 19074944

Reliene R, Fleming SM, Chesselet MF and Schiestl RH (2008) Effects of antioxidants on cancer prevention and neuromotor performance in Atm deficient mice. Food Chem Toxicol, 46:1371-7. PMID 18037553

Chesselet MF, Fleming S, Mortazavi F and Meurers B (2008) Strengths and limitations of genetic mouse models of Parkinson's disease. Parkinsonism Relat Disord :S84-7. PMID 18585084

Fei H, Grygoruk A, Brooks ES, Chen A and Krantz DE (2008) Trafficking of vesicular neurotransmitter transporters. Traffic :1425-36. PMID 18507811

Fleming SM, Tetreault NA, Mulligan CK, Hutson CB, Masliah E and Chesselet MF (2008) Olfactory deficits in mice overexpressing human wildtype alpha-synuclein. Eur J Neurosci :247-56. PMID 18702696

Wang L, Fleming SM, Chesselet MF and Taché Y (2008) Abnormal colonic motility in mice overexpressing human wild-type alpha-synuclein. Neuroreport 10.1097:873-6. PMID 18463504

Meredith GE, Sonsalla PK and Chesselet MF (2008) Animal models of Parkinson's disease progression. Acta Neuropathol 10.1007:385-98. PMID 18273623

Wahner AD, Bronstein JM, Bordelon YM and Ritz B (2008) Statin use and the risk of Parkinson disease. Neurology :1418-22. PMID 18184918

Cheng EM, Siderowf AD, Swarztrauber K, Lee M, Vassar S, Jacob E, Eisa MS and Vickrey BG (2008) Disparities of care in veterans with Parkinson's disease. Parkinsonism Relat Disord :8-14. PMID 17702625

Chesselet MF (2008) In vivo alpha-synuclein overexpression in rodents: a useful model of Parkinson's disease? Exp Neurol :22-7. PMID 17949715

Grandjean P, Bellinger D, Bergman A, Cordier S, Davey-Smith G, Eskenazi B, Gee D, Gray K, Hanson M, van den Hazel P, Heindel JJ, Heinzow B, Hertz-Picciotto I, Hu H, Huang TT, Jensen TK, Landrigan PJ, McMillen IC, Murata K, Ritz B, Schoeters G, Skakkebaek NE, Skerfving S and Weihe P (2008) The faroes statement: human health effects of developmental exposure to chemicals in our environment. Basic Clin Pharmacol Toxicol :73-5. PMID 18226057

Fernagut PO, Hutson CB, Fleming SM, Tetreaut NA, Salcedo J, Masliah E and Chesselet MF (2008) Behavioral and histopathological consequences of paraquat intoxication in mice: effects of alpha-synuclein over-expression. Synapse 10.1002:991-1001. PMID 17879265

 

Public Health Statement

The goal of the UCLA Morris K Udall Parkinson Disease Center of Excellence is to elucidate the underlying cellular and molecular mechanisms of dysfunction in Parkinson’s disease, which will likely present us with new neuroprotective and/or therapeutic treatments to slow down or halt the progression of disease.

Our team of scientists uses a comprehensive and multi-pronged approach to answer the question “what are the genetic, cellular, and environmental events which ultimately lead to the degeneration of neurons and disease manifestation?” Utilizing epidemiological studies in humans, and molecular, anatomical, behavioral and electrophysiological studies in cellular and genetic mouse models, our aim is to uncover the early and possibly causative processes before there is significant cell loss, which could lead to greatly improved treatment options.

The availability of several genetic animal models of Parkinson’s disease has greatly enhanced our ability to study the events that precede (and possibly, directly or indirectly, cause) the degeneration of the dopaminergic neurons of the substantia nigra.  Since diagnosis of PD currently depends on the presence of motor symptoms (which usually appear after significant cell loss has occurred in the substantia nigra), these genetic animal models are critical in answering questions about the underlying causes of degeneration. These animal models have also enabled us to look beyond the loss of dopaminergic neurons in the substantia nigra, to areas within and outside the brain that are involved in a number of significant, non-motor symptoms such as digestive and cardiovascular dysfunction, olfactory deficits, sleep disturbances and emotional impairments. More importantly, investigating the specific molecules and proteins that are involved in early dysfunction or neuroprotection should provide us with potential and novel targets for therapeutic intervention.

During the past year, we have made progress in a number of fronts; for example, the detailed characterization of olfactory deficits in a mouse model (overexpressing alpha-synuclein) has established a reliable means for conducting pre-clinical tests, as evidenced by our collaboration with a number of biotech companies to evaluate the effectiveness of novel potential therapeutic agents.  In addition, we are continuing our characterization of non-motor deficits in these mouse models, including more detailed studies of gastric motility deficits, cardiovascular dysfunction, and cognitive alterations.  These studies show that our mouse models are a valuable tool for studying PD at an early stage, prior to the loss of dopaminergic neurons, by exhibiting the same types of non-motor symptoms frequently observed in patients prior to the onset of parkinsonism.

In parallel, we are completing the neuroanatomical and histopathological characterization of our mouse models, as well as establishing new genetic models that will be useful in studying the various aspects of PD. Using molecular techniques, we are analyzing genes whose expression is increased in the substantia nigra dopaminergic neurons prior to degeneration, and possibly involved in neuroprotection.  We are also investigating the progression of electrophysiological alterations and related changes in dopamine homeostasis in several different genetic modifications that model PD in the mouse, and evaluating whether and how these changes affect other neurotransmitter systems in the brain.

The ongoing large-scale epidemiological studies conducted by the UCLA Udall Center takes advantage of a large and well-characterized cohort of PD patients in the California Central Valley agricultural area. This project focuses on how environmental, behavioral, and social factors such as pesticide exposure, physical activity, stress, coping, and social support, influence the development and rate of progression of motor and key non-motor manifestations in PD, including cognitive impairment and depression.  As an important component of this project, an improved and more efficient Health Related Quality of Life measure is being developed and will be made publicly available to enable a more accurate and effective way of evaluating the progression of disease and its impact on the patient’s quality of life.