Mitochondrial Transcription Factor A Heterozygosity Leads to Oxidative Stress, Mitochondrial Damage, and Cardiac Injury in S. Aureus Sepsis in Mice

2015 ◽  
Vol 87 ◽  
pp. S41-S42
Author(s):  
Jeffrey E. Keenan ◽  
Hagir B. Suliman ◽  
Eli C. Colman ◽  
Anne D. Cherry ◽  
Claude A. Piantadosi
Keyword(s):  
Oxidative Stress ◽  
Transcription Factor ◽  
Cardiac Injury ◽  
Mitochondrial Damage ◽  
Mitochondrial Transcription ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Transcription Factor A

scholarly journals Administration of Enalapril Started Late in Life Attenuates Hypertrophy and Oxidative Stress Burden, Increases Mitochondrial Mass, and Modulates Mitochondrial Quality Control Signaling in the Rat Heart

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 177 ◽  
Author(s):  
Anna Picca ◽  
Giuseppe Sirago ◽  
Vito Pesce ◽  
Angela Maria Serena Lezza ◽  
Riccardo Calvani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Quality Control ◽  
Transcription Factor ◽  
Oxidative Damage ◽  
Mitochondrial Quality Control ◽  
Mitochondrial Transcription ◽  
Mitochondrial Mass ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Transcription Factor A ◽  
And Oxidative Stress

Mitochondrial dysfunction is a relevant mechanism in cardiac aging. Here, we investigated the effects of late-life enalapril administration at a non-antihypertensive dose on mitochondrial genomic stability, oxidative damage, and mitochondrial quality control (MQC) signaling in the hearts of aged rats. The protein expression of selected mediators (i.e., mitochondrial antioxidant enzymes, energy metabolism, mitochondrial biogenesis, dynamics, and autophagy) was measured in old rats randomly assigned to receive enalapril (n = 8) or placebo (n = 8) from 24 to 27 months of age. We also assessed mitochondrial DNA (mtDNA) content, citrate synthase activity, oxidative lesions to protein and mtDNA (i.e., carbonyls and the abundance of mtDNA4834 deletion), and the mitochondrial transcription factor A (TFAM) binding to specific mtDNA regions. Enalapril attenuated cardiac hypertrophy and oxidative stress-derived damage (mtDNA oxidation, mtDNA4834 deletion, and protein carbonylation), while increasing mitochondrial antioxidant defenses. The binding of mitochondrial transcription factor A to mtDNA regions involved in replication and deletion generation was enhanced following enalapril administration. Increased mitochondrial mass as well as mitochondriogenesis and autophagy signaling were found in enalapril-treated rats. Late-life enalapril administration mitigates age-dependent cardiac hypertrophy and oxidative damage, while increasing mitochondrial mass and modulating MQC signaling. Further analyses are needed to conclusively establish whether enalapril may offer cardioprotection during aging.

Abstract 1371: Overexpression Of Mitochondrial Transcription Factor A Protects Failing Myocardium From Oxidative Stress

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Masayoshi Yoshida ◽  
Tomomi Ide ◽  
Mayumi Yamato ◽  
Masaki Ikeuchi ◽  
Takaki Tsutsumi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Transcription Factor ◽  
Hela Cells ◽  
Nuclear Dna ◽  
Mitochondrial Transcription ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Transcription Factor A

Background: Reactive oxygen species (ROS) from mitochondria play a pivotal role in the pathogenesis and progression of heart failure. Mitochondrial transcription factor A (TFAM), a nucleus-encoded protein, in mitochondria promotes transcription of mitochondrial DNA (mtDNA), maintains mtDNA, and increases mtDNA copy number. We previously reported that overexpression of human TFAM ameliorated cardiac remodeling and improved survival by maintaining mitochondrial function. We investigated whether those beneficial effects result from the increase of antioxidative properties both in vivo and in vitro. Methods and Results: [in vivo study] We created myocardial infarction (MI) in wild type (WT) mice and human TFAM transgenic (TG) mice as a model of heart failure. We evaluated free radical generation by in vivo ESR on 28th day after the operation. MI size did not different between WT and MI. Overexpression of TFAM ameliorated MI-induced cardiac hypertrophy (histology) and LV dysfunction (2D echo and cath). Furthermore, the rate of signal decay in in vivo ESR, indicative of oxidative stress, was accelerated in WT-MI (0.10 ± 0.01 vs 0.19 ± 0.02/min, n=4–5, P<0.01) whereas decelerated in TG-MI (0.12 ± 0.02/min; n=4, P<0.01). DNA microarrays analysis of myocardium (8 weeks old, male) indicated that TG overexpressed (double or more) antioxidant relevant genes mostly encoded in nuclear DNA, such as Mthfd2 and Adh1 without affecting mitochondrial respiratory enzyme activities. [in vitro study] We measured superoxide in Hela cells using Dihydroethidium in the presence of rotenone, a complex I inhibitor. Overexpression of TFAM in Hela cells significantly reduced superoxide production (72.8 %). Conclusion: Overexpression of TFAM suppresses ROS. Such an antioxidative property of TFAM may contribute to its powerful anti-remodeling effect in failing heart.

scholarly journals Mitochondrial transcription factor A in RORγt+ lymphocytes regulate small intestine homeostasis and metabolism

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zheng Fu ◽  
Joseph W. Dean ◽  
Lifeng Xiong ◽  
Michael W. Dougherty ◽  
Kristen N. Oliff ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Small Intestine ◽  
Th17 Cells ◽  
Tissue Remodeling ◽  
Mitochondrial Transcription ◽  
Mitochondrial Transcription Factor ◽  
Tuft Cell ◽  
Mitochondrial Transcription Factor A

AbstractRORγt+ lymphocytes, including interleukin 17 (IL-17)-producing gamma delta T (γδT17) cells, T helper 17 (Th17) cells, and group 3 innate lymphoid cells (ILC3s), are important immune regulators. Compared to Th17 cells and ILC3s, γδT17 cell metabolism and its role in tissue homeostasis remains poorly understood. Here, we report that the tissue milieu shapes splenic and intestinal γδT17 cell gene signatures. Conditional deletion of mitochondrial transcription factor A (Tfam) in RORγt+ lymphocytes significantly affects systemic γδT17 cell maintenance and reduces ILC3s without affecting Th17 cells in the gut. In vivo deletion of Tfam in RORγt+ lymphocytes, especially in γδT17 cells, results in small intestine tissue remodeling and increases small intestine length by enhancing the type 2 immune responses in mice. Moreover, these mice show dysregulation of the small intestine transcriptome and metabolism with less body weight but enhanced anti-helminth immunity. IL-22, a cytokine produced by RORγt+ lymphocytes inhibits IL-13-induced tuft cell differentiation in vitro, and suppresses the tuft cell-type 2 immune circuit and small intestine lengthening in vivo, highlighting its key role in gut tissue remodeling.

141 Mitochondrial transcription factor a mitochondrial DNA repair

Mitochondrion ◽  
2010 ◽  
Vol 10 (2) ◽  
pp. 240
Author(s):  
Deborah L. Croteau ◽  
Anne-Cécile V. Bayne ◽  
Chandrika Canugovi ◽  
Scott Maynard ◽  
Nadja de Souza-Pinto ◽  
...  
Keyword(s):  
Dna Repair ◽  
Transcription Factor ◽  
Mitochondrial Dna ◽  
Mitochondrial Transcription ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Dna Repair ◽  
Mitochondrial Transcription Factor A

Selected Contribution: Effects of contractile activity on mitochondrial transcription factor A expression in skeletal muscle

2001 ◽  
Vol 90 (1) ◽  
pp. 389-396 ◽  
Author(s):  
Joe W. Gordon ◽  
Arne A. Rungi ◽  
Hidetoshi Inagaki ◽  
David A. Hood
Keyword(s):  
Skeletal Muscle ◽  
Transcription Factor ◽  
Mitochondrial Biogenesis ◽  
Contractile Activity ◽  
Regulatory Protein ◽  
Mrna Levels ◽  
Mitochondrial Transcription ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Transcription Factor A ◽  
Mitochondrial Transcript

Mitochondrial transcription factor A (Tfam) is a nuclear-encoded gene product that is imported into mitochondria and is required for the transcription of mitochondrial DNA (mtDNA). We hypothesized that conditions known to produce mitochondrial biogenesis in skeletal muscle would be preceded by an increase in Tfam expression. Therefore, rat muscle was stimulated (10 Hz, 3 h/day). Tfam mRNA levels were significantly elevated (by 55%) at 4 days and returned to control levels at 14 days. Tfam import into intermyofibrillar (IMF) mitochondria was increased by 52 and 61% ( P < 0.05) at 5 and 7 days, respectively. This corresponded to an increase in the level of import machinery components. Immunoblotting data indicated that IMF Tfam protein content was increased by 63% ( P < 0.05) at 7 days of stimulation. This was associated with a 49% ( P < 0.05) increase in complex formation at the mtDNA promoter and a 65% ( P< 0.05) increase in the levels of a mitochondrial transcript, cytochrome- c oxidase (COX) subunit III. Similarly, COX enzyme activity was elevated by 71% ( P < 0.05) after 7 days of contractile activity. These results indicate that early events in mitochondrial biogenesis include increases in Tfam mRNA, followed by accelerations in mitochondrial import and increased Tfam content, which correspond with increased binding to the mtDNA promoter region. This was accompanied by increased mitochondrial transcript levels and elevated COX activity. These data support the role of Tfam as a regulatory protein involved in contractile activity-induced mitochondrial biogenesis.

A human mitochondrial transcriptional activator can functionally replace a yeast mitochondrial HMG-box protein both in vivo and in vitro

1993 ◽  
Vol 13 (3) ◽  
pp. 1951-1961
Author(s):  
M A Parisi ◽  
B Xu ◽  
D A Clayton
Keyword(s):  
Transcription Factor ◽  
Mitochondrial Dna ◽  
Nuclear Gene ◽  
Transcriptional Activator ◽  
Yeast Mitochondria ◽  
Yeast Protein ◽  
Mitochondrial Transcription ◽  
Mitochondrial Transcription Factor ◽  
Mitochondrial Transcription Factor A

Human mitochondrial transcription factor A is a 25-kDa protein that binds immediately upstream of the two major mitochondrial promoters, thereby leading to correct and efficient initiation of transcription. Although the nature of yeast mitochondrial promoters is significantly different from that of human promoters, a potential functional homolog of the human transcriptional activator protein has been previously identified in yeast mitochondria. The importance of the yeast protein in yeast mitochondrial DNA function has been shown by inactivation of its nuclear gene (ABF2) in Saccharomyces cerevisiae cells resulting in loss of mitochondrial DNA. We report here that the nuclear gene for human mitochondrial transcription factor A can be stably expressed in yeast cells devoid of the yeast homolog protein. The human protein is imported efficiently into yeast mitochondria, is processed correctly, and rescues the loss-of-mitochondrial DNA phenotype in a yeast abf2 strain, thus functionally substituting for the yeast protein. Both human and yeast proteins affect yeast mitochondrial transcription initiation in vitro, suggesting that the two proteins may have a common role in this fundamental process.

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