TFAM overexpression reduces pathological cardiac remodeling

Kunkel, G; Kunkel, Christopher J.; Ozuna, Hazel; Miralda, Irina; Tyagi, Suresh C.

doi:10.1007/s11010-018-3459-9

Cited by 23 publications

(19 citation statements)

References 27 publications

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“…Conversely, high TFAM expression in transgenic mice increased the number of mtDNA copies, showing that this increase may improve severe symptoms of certain mitochondrial diseases [37]. It has also been reported that an unbalance in the mtDNA copy number due to TFAM alterations may be associated with many neurodegenerative and cardiac diseases, as well as cancer [38–39].…”

Section: Discussionmentioning

confidence: 99%

“…When KO’d, the absence of TFAM induces the activation of proteases Calpain1, MMP9 and NFAT4, resulting in pathological remodeling of the heart and increased ROS production. So, when overexpressed, TFAM reduced all of these HF effects by inhibiting the NFAT4-MMP9 cardiac remodeling cascade, postulating TFAM as a possible therapeutic approach to cardiac pathologies [38–39]…”

Section: Discussionmentioning

confidence: 99%

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Edition of TFAM gene by CRISPR/Cas9 technology in bovine model

et al. 2019

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The mitochondrial transcription factor A ( TFAM ) is a mitochondrial DNA (mtDNA) binding protein essential for the initiation of transcription and genome maintenance. Recently it was demonstrated that the primary role of TFAM is to maintain the integrity of mtDNA and that it is a key regulator of mtDNA copy number. It was also shown that TFAM plays a central role in the mtDNA stress-mediated inflammatory response. In our study, we proposed to evaluate the possibility of editing the TFAM gene by CRISPR/Cas9 technology in bovine fibroblasts, as TFAM regulates the replication specificity of mtDNA. We further attempted to maintain these cells in culture post edition in a medium supplemented with uridine and pyruvate to mimic Rho zero cells that are capable of surviving without mtDNA, because it is known that the TFAM gene is lethal in knockout mice and chicken. Moreover, we evaluated the effects of TFAM modification on mtDNA copy number. The CRISPR gRNA was designed to target exon 1 of the bovine TFAM gene and subsequently cloned. Fibroblasts were transfected with Cas9 and control plasmids. After 24 h of transfection, cells were analyzed by flow cytometry to evaluate the efficiency of transfection. The site directed-mutation frequency was assessed by T7 endonuclease assay, and cell clones were analyzed for mtDNA copy number by Sanger DNA sequencing. We achieved transfection efficiency of 51.3%. We selected 23 successfully transformed clones for further analysis, and seven of these exhibited directed mutations at the CRISPR/Cas9 targeted site. Moreover, we also found a decrease in mtDNA copy number in the gene edited clones compared to that in the controls. These TFAM gene mutant cells were viable in culture when supplemented with uridine and pyruvate. We conclude that this CRISPR/Cas9 design was efficient, resulting in seven heterozygous mutant clones and opening up the possibility to use these mutant cell lines as a model system to elucidate the role of TFAM in the maintenance of mtDNA integrity.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Edition of TFAM gene by CRISPR/Cas9 technology in bovine model

et al. 2019

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Section: Methodsmentioning

confidence: 99%

“…Ultrasound was performed using Vevo 2100 imaging system; cardiac and aortic data were collected as described previously (Kunkel et al, 2019). Experimental animals were placed supine FIGURE 4 | Representative Western blot analysis of DNMT, BHMT, and PEMT (A); Musclin, DAAM1, DAAM2, and REDD1 (B); PGC1a, TFAM, UCP1, DRP1 (C), in LV tissue of WT mice on HFD with and without the treatment with PB.…”

Section: Echocardiographymentioning

confidence: 99%

Epigenetics, 1-Carbon Metabolism, and Homocysteine During Dysbiosis

et al. 2021

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Although a high-fat diet (HFD) induces gut dysbiosis and cardiovascular system remodeling, the precise mechanism is unclear. We hypothesize that HFD instigates dysbiosis and cardiac muscle remodeling by inducing matrix metalloproteinases (MMPs), which leads to an increase in white adipose tissue, and treatment with lactobacillus (a ketone body donor from lactate; the substrate for the mitochondria) reverses dysbiosis-induced cardiac injury, in part, by increasing lipolysis (PGC-1α, and UCP1) and adipose tissue browning and decreasing lipogenesis. To test this hypothesis, we used wild type (WT) mice fed with HFD for 16 weeks with/without a probiotic (PB) in water. Cardiac injury was measured by CKMB activity which was found to be robust in HFD-fed mice. Interestingly, CKMB activity was normalized post PB treatment. Levels of free fatty acids (FFAs) and methylation were increased but butyrate was decreased in HFD mice, suggesting an epigenetically governed 1-carbon metabolism along with dysbiosis. Levels of PGC-1α and UCP1 were measured by Western blot analysis, and MMP activity was scored via zymography. Collagen histology was also performed. Contraction of the isolated myocytes was measured employing the ion-optic system, and functions of the heart were estimated by echocardiography. Our results suggest that mice on HFD gained weight and exhibited an increase in blood pressure. These effects were normalized by PB. Levels of fibrosis and MMP-2 activity were robust in HFD mice, and treatment with PB mitigated the fibrosis. Myocyte calcium-dependent contraction was disrupted by HFD, and treatment with PB could restore its function. We conclude that HFD induces dysbiosis, and treatment with PB creates eubiosis and browning of the adipose tissue.

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“…Mitochondrial transcription factor A (TFAM) is essential for the maintenance of mitochondrial DNA (mtDNA) and regulates mtDNA transcription (18). A number of reports have demonstrated that TFAM dysfunction leads to mitochondrial impairment, which causes cardiovascular diseases, such as heart failure and cardiomyopathy (19)(20)(21); however, its role in AF is unknown. The aim of the present study was to investigate the association between TFAM and AF and the effect of TFAM on ATP content in cardiomyocytes.…”

Section: Introductionmentioning

confidence: 99%

Effect of TFAM on ATP content in tachypacing primary cultured cardiomyocytes and atrial fibrillation patients

et al. 2020

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Atrial fibrillation (AF) is one of the most common types of arrhythmia worldwide; although a number of theories have been proposed to explain the mechanisms of AF, the treatment of AF is far from satisfactory. Energy metabolism is associated with the development of AF. Mitochondrial transcription factor A (TFAM) serves a role in the maintenance and transcription of mitochondrial DNA. The present study aimed to investigate the association between TFAM and AF and the effect of TFAM on ATP content in cardiomyocytes. Left atrial appendage tissues were collected from 20 patients with normal sinus rhythm (SR) and 20 patients with AF, and the expression levels of TFAM in SR and AF tissues were evaluated. In addition, a tachypacing model of primary cultured cardiomyocytes was constructed to assess ATP content, cell viability and expression levels of TFAM, mitochondrially encoded (MT)-NADH dehydrogenase 1 (ND1), MT-cytochrome c oxidase 1 (CO1), NADH ubiquinone oxidoreductase core subunit 1 (NDUFS1) and cytochrome c oxidase subunit 6C (COX6C). Finally, the effects of overexpression and inhibition of TFAM on ATP content, cell viability and the expression levels of MT-ND1 and MT-CO1 were investigated. The expression levels of TFAM were decreased in AF tissues compared with SR tissues (P<0.05). The ATP content, cell viability and expression levels of TFAM, MT-ND1 and MT-CO1 were decreased in tachypacing cardiomyocytes compared with non-pacing cardiomyocytes (P<0.05), whereas the expression levels of NDUFS1 and COX6C were not changed (P>0.05). Overexpression of TFAM increased ATP content, cell viability and expression levels of MT-ND1 and MT-CO1 (P<0.05). The inhibition of TFAM decreased ATP content, cell viability and expression levels of MT-ND1 and MT-CO1 (P<0.05). In summary, the results of the present study demonstrated that the expression levels of TFAM were decreased in AF tissues and tachypacing cardiomyocytes and that the restoration of TFAM increased the ATP content by upregulating the expression levels of MT-ND1 and MT-CO1 in tachypacing cardiomyocytes. Thus, TFAM may be a novel beneficial target for treatment of patients with AF.

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TFAM overexpression reduces pathological cardiac remodeling

Cited by 23 publications

References 27 publications

Edition of TFAM gene by CRISPR/Cas9 technology in bovine model

Edition of TFAM gene by CRISPR/Cas9 technology in bovine model

Epigenetics, 1-Carbon Metabolism, and Homocysteine During Dysbiosis

Effect of TFAM on ATP content in tachypacing primary cultured cardiomyocytes and atrial fibrillation patients

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