• 생명과학회지
• /
• 제31권12호
• /
• pp.1057-1065
• /
• 2021

위암 환자에서 미토콘드리아 DNA (mtDNA)의 양적 변화가 보고 되고 있으며 이러한 변화가 위암의 발암이나 진행에 관여되는 것으로 추정되고 있다. 그리나 위암에서 미토콘드리아 단백질이나 mtDNA에 의해 암호화된 산화적 인산화(OXPHOS) 단백질의 양적 변화에 관한 연구는 아직까지 미비한 실정이다. 본 연구에서는 위암환자 조직 및 세포주를 이용하여 mtDNA 양 그리고 미토콘드리아 단백질 및 OXPHOS 단백질의 양을 분석하였다. 또한, mtDNA 양적 변화와 위암 환자의 임상병리학적 특징을 연관 분석하였다. MtDNA 양을 분석하기 위하여 qPCR 기법을 그리고 단백질 분석에는 Western blot 기법을 각각 활용하였다. 총 27개의 위암 환자 샘플에서 약 80%에 해당하는 22개의 환자 위암조직에서 정상조직에 비해 mtDNA 양이 감소하였으며, 나머지 환자에서는 mtDNA 양이 증가하였다. 이러한 mtDNA 양이 감소한 위암 조직 샘플에서는 미토콘드리아 단백질 및 OXPHOS 단백질의 양도 같이 감소하였다. 한편, 본 연구에 사용된 총 5개의 위암 세포주 모두에서 mtDNA 양이 감소하였다 그러나 위암 세포주에서는 mtDNA 양적 감소와 미토콘드리아 단백질 및 OXPHOS 단백질의 양적 감소가 항상 일치하지는 않았다. 이러한 연구결과는 위암 조직 및 세포주에서 mtDNA 양의 감소가 흔하며 이는 mtDNA 양적 변화가 위암의 생성에 관여함을 제시한다.

• BMB Reports
• /
• 제57권1호
• /
• pp.19-29
• /
• 2024

Mitochondrial DNA (mtDNA), a multicopy genome found in mitochondria, is crucial for oxidative phosphorylation. Mutations in mtDNA can lead to severe mitochondrial dysfunction in tissues and organs with high energy demand. MtDNA mutations are closely associated with mitochondrial and age-related disease. To better understand the functional role of mtDNA and work toward developing therapeutics, it is essential to advance technology that is capable of manipulating the mitochondrial genome. This review discusses ongoing efforts in mitochondrial genome editing with mtDNA nucleases and base editors, including the tools, delivery strategies, and applications. Future advances in mitochondrial genome editing to address challenges regarding their efficiency and specificity can achieve the promise of therapeutic genome editing.

• Journal of Radiation Protection and Research
• /
• 제36권3호
• /
• pp.119-126
• /
• 2011

Mitochondrial DNA (mtDNA) deletion is a well-known marker for oxidative stress and aging, and contributes to harmful effects in cultured cells and animal tissues. mtDNA biogenesis genes (NRF-1, TFAM) are essential for the maintenance of mtDNA, as well as the transcription and replication of mitochondrial genomes. Considering that oxidative stress is known to affect mitochondrial biogenesis, we hypothesized that ionizing radiation (IR)-induced reactive oxygen species (ROS) causes mtDNA deletion by modulating the mitochondrial biogenesis, thereby leading to cellular senescence. Therefore, we examined the effects of IR on ROS levels, cellular senescence, mitochondrial biogenesis, and mtDNA deletion in IMR-90 human lung fibroblast cells. Young IMR-90 cells at population doubling (PD) 39 were irradiated at 4 or 8 Gy. Old cells at PD55, and H2O2-treated young cells at PD 39, were compared as a positive control. The IR increased the intracellular ROS level, senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity, and mtDNA common deletion (4977 bp), and it decreased the mRNA expression of NRF-1 and TFAM in IMR-90 cells. Similar results were also observed in old cells (PD 55) and $H_2O_2$-treated young cells. To confirm that a increase in ROS level is essential for mtDNA deletion and changes of mitochondrial biogenesis in irradiated cells, the effects of N-acetylcysteine (NAC) were examined. In irradiated and $H_2O_2$-treated cells, 5 mM NAC significantly attenuated the increases of ROS, mtDNA deletion, and SA-${\beta}$-gal activity, and recovered from decreased expressions of NRF-1 and TFAM mRNA. These results suggest that ROS is a key cause of IR-induced mtDNA deletion, and the suppression of the mitochondrial biogenesis gene may mediate this process.

• 생명과학회지
• /
• 제16권2호
• /
• pp.240-244
• /
• 2006

본 실험에서는 토마토의 종자를 기내 배양하여 얻어진 1g 이하의 무균 잎 조직을 이용하여 미토콘드리아를 분리 정제하여 MitoTracker를 이용하여 세포생물학적으로 확인하였고, 이들의 mt를 이용하여 미토콘드리아 DNA와 RNA를 추출과 검정을 하였다. 또한 고농도의 이온성을 이용하여 미토콘드리아와 mtDNA 및 mtRNA을 추출할 수 있었으며, 식물의 여러 종류에도 사용되어질 수 있을 것이다. mtDNA는 PCR 분석에 의하여 plastid DNA와 혼재되어 있지 않음을 확인하였다. mtRNA는 RT-PCR 분석을 통하여 plastid RNA와 흔재되어 있지 않음을 확인할 수 있었다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제23권6호
• /
• pp.519-528
• /
• 2019

Mitochondrial dysfunction is closely associated with reactive oxygen species (ROS) generation and oxidative stress in cells. On the other hand, modulation of the cellular antioxidant defense system by changes in the mitochondrial DNA (mtDNA) content is largely unknown. To determine the relationship between the cellular mtDNA content and defense system against oxidative stress, this study examined a set of myoblasts containing a depleted or reverted mtDNA content. A change in the cellular mtDNA content modulated the expression of antioxidant enzymes in myoblasts. In particular, the expression and activity of glutathione peroxidase (GPx) and catalase were inversely correlated with the mtDNA content in myoblasts. The depletion of mtDNA decreased both the reduced glutathione (GSH) and oxidized glutathione (GSSG) slightly, whereas the cellular redox status, as assessed by the GSH/GSSG ratio, was similar to that of the control. Interestingly, the steady-state level of the intracellular ROS, which depends on the reciprocal actions between ROS generation and detoxification, was reduced significantly and the lethality induced by $H_2O_2$ was alleviated by mtDNA depletion in myoblasts. Therefore, these results suggest that the ROS homeostasis and antioxidant enzymes are modulated by the cellular mtDNA content and that the increased expression and activity of GPx and catalase through the depletion of mtDNA are closely associated with an alleviation of the oxidative stress in myoblasts.

• Interdisciplinary Bio Central
• /
• 제3권4호
• /
• pp.16.1-16.8
• /
• 2011

Defects in mitochondrial DNA (mtDNA) cause many human diseases and are critical factors that contribute to aging. The mechanisms of maternally-inherited mtDNA mutations are well studied. However, the role of acquired mutations during the aging process is still poorly understood. The most plausible mechanism is that increased reactive oxygen species (ROS) may affect the opening of mitochondrial voltage dependent anion channel (VDAC) and thus results in damage to mtDNA. This review focuses on recent trends in mtDNA research and the mutations that appear to be associated with increased ROS.

• 대한수의학회지
• /
• 제34권2호
• /
• pp.243-247
• /
• 1994

As a result of the detection of mitochondrial DNA(mtDNA) polymorphism to Thoroughbred and Percheron using 14 restriction enzymes, mtDNA polymorphism of Cheju horse observed in the Bam HI and Sac I. Only in both restriction enzymes two types were classified as of A type, which is high expression frequency and B type, which is low expression frequency. In the other 12 restriction enzymes mtDNA polymorphism was not detected. On the basis of this information mtDNA polymorphism of Cheju horse was examined but was not observed the polymorphism and only A type was expressed both Bam HI and Sac I restriction enzymes. Through this study Cheju horse was demonstrated that lower genetic variation was expressed from the detection of mtDNA polymorphism.

• Journal of Microbiology and Biotechnology
• /
• 제30권9호
• /
• pp.1290-1296
• /
• 2020

Recently, it was reported that entire mammalian mtDNA genomes could be transplanted into the mitochondrial networks of yeast, where they were accurately and stably maintained without rearrangement as intact genomes. Here, it was found that engineered mtDNA genomes could be readily transferred to and steadily maintained in the mitochondria of genetically modified yeast expressing the mouse mitochondrial transcription factor A (Tfam), one of the mitochondrial nucleoid proteins. The transferred mtDNA genomes were stably retained in the Tfam-expressing yeast cells for many generations. These results indicated that the engineered mouse mtDNA genomes introduced in yeast mitochondria could be relocated into the mitochondria of other cells and that the transferred genomes could be maintained within a mitochondrial environment that is highly amenable to mimicry of the biological conditions in mammalian mitochondria.

• 한국응용곤충학회지
• /
• 제37권1호
• /
• pp.23-30
• /
• 1998

DNA의 제한요소단편 다형현상(RFLP)이 유전변이 연구에 널리 이용되고 있다. 본 연구는 파밤나방(Spodoptera exigua(H bner)) 미토콘드리아 DNA(mtDNA)의 RFLP방법을 개발하기 위해 게놈 크기 측정 및 PCR primer들을 선발하였다. 파밤나방의 mtDNA 전체크기는 약 16kb였다. 대부분 곤충 mtDNA에 적합하게 구성된 (Simon et al., 1994)29개 promer들중 21개가 파밤나방의 mtDNA증폭에 적합했다. 이들 primer들을 이용하여 여러 유전자 영역(CO-I, CO-II, Cyt-B, ND-1, 12S rRNA, 16S rRNA 및 일부 tRNA)의 일분 또는 전체를 포함하는 유전자 절편을 증폭시켰다. 일반적으로 다형을 보이는 primer조합을 중심으로 4염기 제한부위를 인식하는 8종의 제한 효소를 통해 분석된 PCR-RFLP는 서로 다은 지역(안동, 경산, 순천) 집단들간에 제한부위에 있어서 차이가 없었으나 일부 영역에서는 길이 차이를 보여 유용한 유전지표로서의 가능성을 제시했다.

• Journal of Applied Biological Chemistry
• /
• 제57권3호
• /
• pp.259-265
• /
• 2014

Mitochondrial DNA (mtDNA)-depleted (${\rho}^0$) cells are often used as mtDNA recipients to study the interaction between the nucleus and mitochondria in mammalian cells. Therefore, it is crucial to obtain mtDNA-depleted cells with many different nuclear backgrounds for the study. Here, we demonstrate a rapid and reliable method to isolate mammalian mtDNA-depleted cells involving treatment with the antimitochondrial agents ethidium bromide (EtBr) and 2',3'-dideoxycytidine (ddC). After a short exposure to EtBr or ddC, followed by rapid clonal isolation, we were able to generate viable mtDNA-depleted cells from mouse and human cells and were able to successfully repopulate them with exogenous mitochondria from platelets isolated from mouse and human blood samples. These mtDNA-depleted cells can be used to characterize the nuclear mitochondrial interactions and to study mtDNA-associated defects in mammalian cells. Our method of isolating mtDNA-depleted cells is practical and applicable to a variety of cell types.