Role of sodium nitroprusside in regulating retinal ganglion cell damage through mitochondrial transcription factor A

2016 ◽  
Vol 635 ◽  
pp. 90-96 ◽  
Author(s):  
Xiao Liu ◽  
Luosheng Tang ◽  
Baihua Chen ◽  
Wenmin Jiang
2014 ◽  
Vol 451 (4) ◽  
pp. 510-515 ◽  
Author(s):  
Yu Yokoyama ◽  
Kazuichi Maruyama ◽  
Kotaro Yamamoto ◽  
Kazuko Omodaka ◽  
Masayuki Yasuda ◽  
...  

2004 ◽  
Vol 24 (22) ◽  
pp. 9823-9834 ◽  
Author(s):  
Tomotake Kanki ◽  
Kippei Ohgaki ◽  
Martina Gaspari ◽  
Claes M. Gustafsson ◽  
Atsushi Fukuoh ◽  
...  

ABSTRACT Mitochondrial transcription factor A (TFAM), a transcription factor for mitochondrial DNA (mtDNA) that also possesses the property of nonspecific DNA binding, is essential for maintenance of mtDNA. To clarify the role of TFAM, we repressed the expression of endogenous TFAM in HeLa cells by RNA interference. The amount of TFAM decreased maximally to about 15% of the normal level at day 3 after RNA interference and then recovered gradually. The amount of mtDNA changed closely in parallel with the daily change in TFAM while in organello transcription of mtDNA at day 3 was maintained at about 50% of the normal level. TFAM lacking its C-terminal 25 amino acids (TFAM-ΔC) marginally activated transcription in vitro. When TFAM-ΔC was expressed at levels comparable to those of endogenous TFAM in HeLa cells, mtDNA increased twofold, suggesting that TFAM-ΔC is as competent in maintaining mtDNA as endogenous TFAM under these conditions. The in organello transcription of TFAM-ΔC-expressing cells was no more than that in the control. Thus, the mtDNA amount is finely correlated with the amount of TFAM but not with the transcription level. We discuss an architectural role for TFAM in the maintenance of mtDNA in addition to its role in transcription activation.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zheng Fu ◽  
Joseph W. Dean ◽  
Lifeng Xiong ◽  
Michael W. Dougherty ◽  
Kristen N. Oliff ◽  
...  

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.


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

2001 ◽  
Vol 90 (1) ◽  
pp. 389-396 ◽  
Author(s):  
Joe W. Gordon ◽  
Arne A. Rungi ◽  
Hidetoshi Inagaki ◽  
David A. Hood

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.


1993 ◽  
Vol 13 (3) ◽  
pp. 1951-1961
Author(s):  
M A Parisi ◽  
B Xu ◽  
D A Clayton

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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