The Murine Common Deletion: Mitochondrial DNA 3,860-bp Deletion after Irradiation

Abstract

This study demonstrates that mice, similar to humans, have a common mitochondrial DNA deletion (3,860 bp) that encodes 5 transfer RNA genes and 5 polypeptide genes that is related to aging, tissue type and radiotoxicity. Our research indicates that the deletion ratio in the liver was significantly higher than in the brain and gut tissues of 8-month-old mice, as compared to 8-week-old mice. Our results also demonstrate that tissue type, oxidative metabolic capacity and radiosensitivity influence the 3,860-bp deletion level. Therefore, this 3,860-bp deletion content may serve as a biomarker of aging and oxidative damage in mice.

Thoracic gamma irradiation-induced obesity in C57BL/6 female mice

“…All genomic and mitochondrial DNA (mtDNA) were extracted from tissues by standard proteolytic digestion followed by phenol/chloroform/isoamyl alcohol purification (Zhang et al 2013). Absorbance at 260 and 280 nm was used for observation of the quantity and quality of the extracted DNA.…”

“…Mitochondrial DNA content change and mutation frequency were measured, as described by Zhang et al (2013). Briefly, the 18S rRNA murine nuclear gene target and the 12S rRNA murine mitochondrial gene target were amplified for measuring mtDNA content changes.…”

“…Akt1 signaling (Karlsson and Zierath 2007;Rametta et al 2013). The primers of gene expression for CPT1a, IRS2, and b-actin were as follows: Quantitative PCR was performed using iQ SYBR Green Supermix (Bio-Rad) with genomic DNA or cDNA and primers on an iCycler IQ multicolor real-time PCR detection system (MyiQ 2.0, Bio-Rad), as previously described (Zhang et al 2013). …”

“…The mitochondria of obese individuals are different from those of lean individuals (Grattagliano et al 2012). We measured ratios of mtDNA to nDNA and mtDNA common deletion (mito-CD) to mtDNA using our previous method (Zhang et al 2013) in the hearts and livers of overweight/ severely overweight and normal weight mice after irradiation ( Figure 6). The decreased mtDNA/nDNA and increased mito-CD/mtDNA ratios from mice 12 months after TRI were 1 ± 0.19 vs. 0.71 ± 0.06 (p < .05) and 1 ± 0.28 vs. 3.21 ± 0.48 (p < .01) (non-TRI vs. TRI, five mice per group, hearts, Figure 6(A)), and 1 ± 0.22 vs. 0.49 ± 0.05 (p < .05) and 1 ± 0.26 vs. 1.83 ± 0.41 (p < .05) (non-TRI vs. TRI, five mice per group, livers, Figure 6(B)), respectively.…”

Age‐associated alterations in murine dermis through inflammatory response with mitochondrial DNA deletions

“…Mitochondrial DNA (mtDNA) mutations and deletions have critical roles in the aging process, including skin aging, and the most frequent deletion is the mtDNA common deletion (CD) . These data largely describe the levels of mtDNA deletions in photo‐aging, but the frequency of mtDNA CD in chronological aged skin has not been documented.…”