We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Mechanisms of TFAM-mediated cardiomyocyte protection.
- Authors
Kunkel, George H.; Chaturvedi, Pankaj; Thelian, Nicholas; Nair, Rohit; Tyagi, Suresh C.
- Abstract
Although mitochondrial transcription factor A (TFAM) is a protective component of mitochondrial DNA and a regulator of calcium and reactive oxygen species (ROS) production, the mechanism remains unclear. In heart failure, TFAM is significantly decreased and cardiomyocyte instability ensues. TFAM inhibits nuclear factor of activated T cells (NFAT), which reduces ROS production; additionally, TFAM transcriptionally activates SERCA2a to decrease free calcium. Therefore, decreasing TFAM vastly increases protease expression and hypertrophic factors, leading to cardiomyocyte functional decline. To examine this hypothesis, treatments of 1.0 μg of a TFAM vector and 1.0 μg of a CRISPR-Cas9 TFAM plasmid were administered to HL-1 cardiomyocytes via lipofectamine transfection. Western blotting and confocal microscopy analysis show that CRISPR-Cas9 knockdown of TFAM significantly increased proteases Calpain1, MMP9, and regulators Serca2a, and NFAT4 protein expression. CRISPR knockdown of TFAM in HL-1 cardiomyocytes upregulates degradation factors, leading to cardiomyocyte instability. Hydrogen peroxide oxidative stress decreased TFAM expression and increased Calpain1, MMP9, and NFAT4 protein expression. TFAM overexpression normalizes pathological hypertrophic factor NFAT4 in the presence of oxidative stress.
- Subjects
TRANSCRIPTION factors; TRANS-regulatory elements (Genetics); REACTIVE oxygen species; T cells; HEART cells
- Publication
Canadian Journal of Physiology & Pharmacology, 2018, Vol 96, Issue 2, p173
- ISSN
0008-4212
- Publication type
Article
- DOI
10.1139/cjpp-2016-0718