Mitophagy is a specialized form of macroautophagy responsible for removal of non-functional mitochondria from the cell. Given the prominent role that mitochondria play in oxidative stress, it has been suggested that mitophagy is critical to protein turnover in skeletal muscle. It is currently impossible to determine how each form of autophagy, including mitophagy, contributes to protein turnover. The immediate goal of this application is to develop bioanalytical approaches to determine mitophagy fluxes in cell cultures and skeletal muscle. The main parameter to measure is mitophagy flux (the rate at which mitophagy occurs) using novel technologies based on individual organelle measurements by capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) and proteomic profiles. The long-term goal is to apply these bioanalytical approaches to characterize the role of mitophagy in human conditions such as hyperthyroidism and aging that are characterized by alterations in protein turnover.
The specific aims of this application are: 1. Define new mitophagy flux analyses based on individual organelle measurements by CE-LIF. 2. Identify organelle-specific proteome changes in abundance, carbonylation and ubiquitination that are associated with changes in mitophagy flux. 3. Determine changes in mitophagy flux in skeletal muscle of hyperthyroid rat, aging rat and aging human models. This work approaches mitophagy from a unique angle, aiming to integrate individual organelle measurements and proteome profiles to define altered mitophagy fluxes with high specificity, even when in the presence of other forms of autophagy. We will the transfer the new technologies to a clinical research setting to investigate mitophagy in human skeletal muscle. Long-term impact of the findings of this work would be the basis for investigating mechanisms of mitophagy and its role in disease and aging.

Public Health Relevance

Mitophagy (degradation of mitochondria) plays a critical role in aging and in disease conditions such as hyperthyroidism, Parkinson's disease, cancer, and diabetes. New techniques that can help monitor mitophagy are needed. We propose to develop and test new techniques to measure mitophagy in cell models, animal tissue, and human tissue biopsies.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
2R01AG020866-10A1
Application #
8319980
Study Section
Instrumentation and Systems Development Study Section (ISD)
Program Officer
Finkelstein, David B
Project Start
2002-04-15
Project End
2016-03-31
Budget Start
2012-04-01
Budget End
2013-03-31
Support Year
10
Fiscal Year
2012
Total Cost
$384,164
Indirect Cost
$116,636
Name
University of Minnesota Twin Cities
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
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Satori, Chad P; Arriaga, Edgar A (2013) Describing autophagy via analysis of individual organelles by capillary electrophoresis with laser induced fluorescence detection. Anal Chem 85:11391-400
Satori, Chad P; Henderson, Michelle M; Krautkramer, Elyse A et al. (2013) Bioanalysis of eukaryotic organelles. Chem Rev 113:2733-811
Wang, Yaohua; Taylor, Thane H; Arriaga, Edgar A (2012) Analysis of the bioactivity of magnetically immunoisolated peroxisomes. Anal Bioanal Chem 402:41-9
Satori, Chad P; Kostal, Vratislav; Arriaga, Edgar A (2011) Individual organelle pH determinations of magnetically enriched endocytic organelles via laser-induced fluorescence detection. Anal Chem 83:7331-9
Wolken, Gregory G; Kostal, Vratislav; Arriaga, Edgar A (2011) Capillary isoelectric focusing of individual mitochondria. Anal Chem 83:612-8

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