This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objective: To further characterize mitochondrial dysfunction in LRRK2G2019S mutant Parkinson disease (PD) patient tissue (M-LRRK2G2019S), determine whether ursodeoxycholic acid (UDCA) also exerts a beneficial effect on mitochondrial dysfunction in nonmanifesting LRRK2G2019S mutation carriers (NM-LRRK2G2019S), and assess UDCA for its beneficial effect on neuronal dysfunction in vivo.
Methods: Intracellular adenosine 5′-triphosphate (ATP) levels, oxygen consumption, and activity of the individual complexes of the mitochondrial respiratory chain as well as mitochondrial morphology were measured in M-LRRK2G2019S, NM-LRRK2G2019S, and controls. UDCA was assessed for its rescue effect on intracellular ATP levels in NM-LRRK2G2019S and in a LRRK2 transgenic fly model with dopaminergic expression of LRRK2G2019S.
Results: Crucial parameters of mitochondrial function were similarly reduced in both M-LRRK2G2019S and NM-LRRK2G2019S with a specific decrease in respiratory chain complex IV activity. Mitochondrial dysfunction precedes changes in mitochondrial morphology but is normalized after siRNA-mediated knockdown of LRRK2. UDCA improved mitochondrial function in NM-LRRK2G2019 and rescued the loss of visual function in LRRK2G2019S flies.
Conclusion: There is clear preclinical impairment of mitochondrial function in NM-LRRK2G2019S that is distinct from the mitochondrial impairment observed in parkin-related PD. The beneficial effect of UDCA on mitochondrial function in both NM-LRRK2G2019S and M-LRRK2G2019S as well as on the function of dopaminergic neurons expressing LRRK2G2019S suggests that UDCA is a promising drug for future neuroprotective trials.
GLOSSARY
- ANOVA=
- analysis of variance;
- ATP=
- adenosine 5′-triphosphate;
- CRF=
- contrast response function;
- EOPD=
- early-onset Parkinson disease;
- FDA=
- Food and Drug Administration;
- M-LRRK2G2019S=
- manifesting LRRK2G2019S carriers;
- NM-LRRK2G2019S=
- nonmanifesting LRRK2G2019S carriers;
- PD=
- Parkinson disease;
- SSVEP=
- steady-state visual evoked potentials;
- TUDCA=
- taurine conjugate;
- UDCA=
- ursodeoxycholic acid
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
↵* These authors contributed equally as joint first authors.
↵‡ These authors contributed equally as joint last authors.
Supplemental data at Neurology.org
Editorial, page 838
- Received March 13, 2014.
- Accepted in final form March 9, 2015.
- © 2015 American Academy of Neurology
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Disputes & Debates: Rapid online correspondence
NOTE: All authors' disclosures must be entered and current in our database before comments can be posted. Enter and update disclosures at http://submit.neurology.org. Exception: replies to comments concerning an article you originally authored do not require updated disclosures.
- Stay timely. Submit only on articles published within the last 8 weeks.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- 200 words maximum.
- 5 references maximum. Reference 1 must be the article on which you are commenting.
- 5 authors maximum. Exception: replies can include all original authors of the article.
- Submitted comments are subject to editing and editor review prior to posting.