Plasma Mitochondrial Peptide Assays as Biomarkers of Environmental Toxin Exposure Mitochondrial dysfunction is associated with a number of chronic diseases and mitochondria are a target for numerous environmental toxins, but no validated circulating markers are available for assessing mitochondrial function or dysfunction resulting from environmental exposures. Mitochondria contain nearly a thousand proteins of nuclear origin, but the mitochondrial chromosome only encodes 13 proteins. We recently identified a family of novel mitochondrial derived peptides (MDPs). These include humanin and six humanin-like peptides we named SHLPs, which potently regulate cell survival and metabolic processes in vitro and in vivo. We propose that ELISA assays for circulating humanin and other MDPs represent robust markers of mitochondrial function and will serve as early indicators of mitochondrial dysfunction associated with environmental insults. Our goals in this project include continued development and characterization of ELISA assays for humanin and SHLPs in humans and mice. Our preliminary data demonstrates abnormalities in their levels in human diseases states associated with mitochondrial dysfunction and in mice subjected to acute doxorubicin exposure. We will also examine the in vitro effects of the mitochondrial toxins Rotenone and Doxorubicin on cell lines and primary cultures in terms of their effect on the expression and production of mitochondrial peptides, and correlate this to measures of mitochondrial function. Finally we will determine the relationship between plasma levels of mitochondrial peptides and mitochondrial dysfunction, in mice exposed to the mitochondrial toxins Rotenone and Doxorubicin in short term and long-term studies. We will assess changes in circulating levels of MDPs following toxin exposure and correlated them to organ-specific levels of these peptides from sacrificed animals as well as to in vivo and ex vivo analysis of mitochondrial function. Together, these studies will establish the utility of circulating mitochondrial peptide assays as markers of mitochondrial dysfunction resulting from environmental toxin exposure and will create a critical set of tools for future studies to monitor humans exposed to such toxins. This will enable prevention and intervention in subclinical stages of diseases related to mitochondrial dysfunction.

Public Health Relevance

of this research to public health We have recently made the unique discovery that the mitochondria is the site of production of previously unrecognized peptides with biological activity that can be detected in the circulation. This represents a paradigm shift from the current approach to assessing mitochondrial function in health and disease. There is a great need to develop early biomarkers for mitochondrial dysfunction. This is true for both chronic diseases related to lifestyle and genetic susceptibility as well as to diseases related to environmental exposure. Our proposed studies will establish the utility of circulating mitochondrial peptide assays as markers of mitochondrial dysfunction resulting from environmental toxin exposure and will create a critical set of tools for future studies to monitor humans exposed to such toxins. This will enable prevention and early intervention in subclinical stages of diseases related to mitochondrial dysfunction. We believe that this project represents a highly responsive approach to the urgent concerns raised regarding the need for the development of assays for mitochondrial function that can be rapidly translated to clinical and population research.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES020812-05
Application #
8697052
Study Section
Special Emphasis Panel (ZES1)
Program Officer
Shaughnessy, Daniel
Project Start
2011-09-19
Project End
2016-06-30
Budget Start
2014-07-01
Budget End
2015-06-30
Support Year
5
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Southern California
Department
Type
Other Specialized Schools
DUNS #
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Mao, Kai; Quipildor, Gabriela Farias; Tabrizian, Tahmineh et al. (2018) Late-life targeting of the IGF-1 receptor improves healthspan and lifespan in female mice. Nat Commun 9:2394
Kim, Su-Jeong; Xiao, Jialin; Cohen, Pinchas et al. (2017) Subcellular Fractionation for ERK Activation Upon Mitochondrial-derived Peptide Treatment. J Vis Exp :
Davies, Joanna M S; Cillard, Josiane; Friguet, Bertrand et al. (2017) The Oxygen Paradox, the French Paradox, and age-related diseases. Geroscience 39:499-550
Cobb, Laura J; Lee, Changhan; Xiao, Jialin et al. (2016) Naturally occurring mitochondrial-derived peptides are age-dependent regulators of apoptosis, insulin sensitivity, and inflammatory markers. Aging (Albany NY) 8:796-809
Huffman, Derek M; Farias Quipildor, Gabriela; Mao, Kai et al. (2016) Central insulin-like growth factor-1 (IGF-1) restores whole-body insulin action in a model of age-related insulin resistance and IGF-1 decline. Aging Cell 15:181-6
Sreekumar, Parameswaran G; Ishikawa, Keijiro; Spee, Chris et al. (2016) The Mitochondrial-Derived Peptide Humanin Protects RPE Cells From Oxidative Stress, Senescence, and Mitochondrial Dysfunction. Invest Ophthalmol Vis Sci 57:1238-53
Mitchell, Sarah J; Madrigal-Matute, Julio; Scheibye-Knudsen, Morten et al. (2016) Effects of Sex, Strain, and Energy Intake on Hallmarks of Aging in Mice. Cell Metab 23:1093-1112
Xiao, J; Kim, S-J; Cohen, P et al. (2016) Humanin: Functional Interfaces with IGF-I. Growth Horm IGF Res 29:21-27
Kim, Su-Jeong; Guerrero, Noel; Wassef, Gabriella et al. (2016) The mitochondrial-derived peptide humanin activates the ERK1/2, AKT, and STAT3 signaling pathways and has age-dependent signaling differences in the hippocampus. Oncotarget 7:46899-46912
Lee, Changhan; Kim, Kyung Hwa; Cohen, Pinchas (2016) MOTS-c: A novel mitochondrial-derived peptide regulating muscle and fat metabolism. Free Radic Biol Med 100:182-187

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