The Effects of AICAR and Rapamycin on Mitochondrial Function in Immortalized Mitochondrial DNA Mutator Murine Embryonic Fibroblasts

Authors

Vedad Delic, University of Alabama, Birmingham
Kenyaria Noble, University of South Florida
Sandra Zivkovic, University of South Florida
Tam-Anh Phan, University of South FloridaFollow
Christian Reynes, University of South Florida
Yumeng Zhang, University of South FloridaFollow
Oluwakemi Sowemimo, University of South FloridaFollow
Charles Claybaker, University of South Florida
Yen Ta, University of South FloridaFollow
Vinh B. Dinh, University of South Florida
Josean Cruz, University of South Florida
Tomas A. Prolla, University of Wisconsin-Madison
Patrick C. Bradshaw, East Tennessee State University

Document Type

Article

Publication Date

11-2018

Keywords

mTOR, AMP kinase, Aging, Mitochondria, Rapamycin, Pyruvate addiction

Abstract

Mitochondrial DNA mutations accumulate with age and may play a role in stem cell aging as suggested by the premature aging phenotype of mitochondrial DNA polymerase gamma (POLG) exonuclease-deficient mice. Therefore, E1A immortalized murine embryonic fibroblasts (MEFs) from POLG exonuclease-deficient and wild-type (WT) mice were constructed. Surprisingly, when some E1A immortalized MEF lines were cultured in pyruvate-containing media they slowly became addicted to the pyruvate. The POLG exonuclease-deficient MEFs were more sensitive to several mitochondrial inhibitors and showed increased reactive oxygen species (ROS) production under standard conditions. When cultured in pyruvate-containing media, POLG exonuclease-deficient MEFs showed decreased oxygen consumption compared to controls. Increased AMP-activated protein kinase (AMPK) signaling and decreased mammalian target of rapamycin (mTOR) signaling delayed aging and influenced mitochondrial function. Therefore, the effects of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an AMPK activator, or rapamycin, an mTOR inhibitor, on measures of mitochondrial function were determined. Rapamycin treatment transiently increased respiration only in WT MEFs and, under most conditions, increased ATP levels. Short term AICAR treatment transiently increased ROS production and, under most conditions, decreased ATP levels. Chronic AICAR treatment decreased respiration and ROS production in WT MEFs. These results demonstrate the context-dependent effects of AICAR and rapamycin on mitochondrial function.

Rights Information

This work is licensed under a Creative Commons Attribution 3.0 License.

DOI

https://doi.org/10.1242/bio.033852

Citation / Publisher Attribution

Biology Open, v. 7, no. 11, art. bio033852

Scholar Commons Citation

Delic, Vedad; Noble, Kenyaria; Zivkovic, Sandra; Phan, Tam-Anh; Reynes, Christian; Zhang, Yumeng; Sowemimo, Oluwakemi; Claybaker, Charles; Ta, Yen; Dinh, Vinh B.; Cruz, Josean; Prolla, Tomas A.; and Bradshaw, Patrick C., "The Effects of AICAR and Rapamycin on Mitochondrial Function in Immortalized Mitochondrial DNA Mutator Murine Embryonic Fibroblasts" (2018). USF Alumni and Student Publications. 2.
https://digitalcommons.usf.edu/alumni_pubs/2