• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2008년도 Proceedings of the Convention
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• pp.23-30
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• 2008

Mitochondria biogenesis requires a coordination of two genomes, nuclear DNA (nDNA) and mitochondrial DNA (mtDNA). Disruption of mitochondria function leads to a loss of mitochondrial membrane potential and ATP generating capacity and consequently results in chronic degenerative diseases including insulin resistance, metabolic syndrome and neurodegenerative diseases. Although PPAR-${\gamma}$ coactivator-$1{\alpha}$ (PGC-$1{\alpha}$) was discovered as a central regulator of mitochondria biogenesis and a transcriptional co-activator of nuclear respiratory factor (NRF) and mitochondrial transcription factor A (Tfam), the expressions of PGC-$1{\alpha}$, NRF and Tfam were not significantly altered in tissues showing abnormal mitochondria functions. This observation suggests that there should be another regulator(s) for mitochondria function. Here, we demonstrate microRNAs (miRNAs) can modulate mitochondria function. Overexpression of microRNA dissipated mitochondrial membrane potential and increased ROS production in vitro and in vivo. It will be discussed the target of microRNA and its role in metabolic syndrome.

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

• 생명과학회지
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• 제16권2호
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• pp.240-244
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• 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.

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

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.12-12
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• 2001

To get insight into the nature of foreign mitochondria and syngamy during mammalian fertilization we compared fertilization processes in porcine oocytes following microinjection of porcine or mouse spermatozoa. Pronuclear movement, sperm mitochondria, and DNA synthesis were imaged with propidium iodide, mitotracker, and BrdU under confocal laser scanning microscope. Intracytoplasmic injection of either porcine or mouse spermatzoon activated porcine oocytes without additional parthengenetic stimulation. Foreign mitochondria in either mouse or porcine sperm midpiece were introduced into porcine oocytes following sperm injection, but rapidly disappeared from the actively developing porcine oocytes. BrdU experiment showed new DNA synthesis in porcine oocytes following injection of mouse spermatozoon or sperm head. At 24 h after injection of mouse isolated sperm head or a spermatozoon, mitoic metaphase was seen in oocyte, but they did not go to normal cell division (Table). These results suggest that pronuclear formation, foreign mitochondria disruption, DNA synthesis and syngamy formation during fertilization are not species specific processes.(Table Omitted).

• BMB Reports
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• 제40권6호
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• pp.1095-1099
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• 2007

Endonuclease G (EndoG) is a mitochondrial non-specific nuclease that is highly conserved among the eukaryotes. Although the precise role of EndoG in mitochondria is not yet known, the enzyme is released from the mitochondria and digests nuclear DNA during apoptosis in mammalian cells. Schizosaccharomyces pombe has an EndoG homolog Pnu1p (previously named SpNuc1) that is produced as a precursor protein with a mitochondrial targeting sequence. During the sorting into mitochondria the signal sequence is cleaved to yield the functionally active endonuclease. From the analogy to EndoG, active extramitochondrial Pnu1p may trigger cell killing by degrading nuclear DNA. Here, we tested this possibility by expressing a truncated Pnu1p lacking the signal sequence in the extramitochondrial region of pnu1-deleted cells. The truncated Pnu1p was localized in the cytosol and nuclei of yeast cells. And ectopic expression of active Pnu1p led to cell death with fragmentation of nuclear DNA. This suggests that the Pnu1p is possibly involved in a certain type of yeast cell death via DNA fragmentation. Although expression of human Bak in S. pombe was lethal, Pnu1p nuclease is not necessary for hBak-induced cell death.

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1335-1340
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• 2006

It has been found that a number of diseases are associated with mutations in the mitochondrial DNA. Therapeutic gene delivery to mitochondria has been suggested as a clinical option for these diseases. In this study, we developed a gene carrier to mitochondria by the conjugation of mitochondrial leader peptide (LP) to polyethylenimine (PEI). Mitochondrial LP conjugated PEI (PEI-LP) was synthesized with low molecular weight PEI (2,000 Da, PEI2K). Gel retardation assay showed that PEI2K-LP formed complexes at a 1.0/1 weight ratio. In addition, PEI2K-LP protected DNA from the enzymatic degradation for at least 60 min, while naked DNA was completely degraded within 20 min. PEI2K-LP was compared with LP conjugated high molecular weight PEI (25,000 Da, PEI25K) in terms of toxicity and delivery efficiency. MTT assay showed that PEI2K-LP had much lower cytotoxicity than PEI25K-LP to 293 cells. In addition, cell-free DNA delivery assay showed that PEI2K-LP delivered more DNA to mitochondria at a 1.8/1 weight ratio than naked DNA or PEI. This result suggests that PEI2K-LP may be useful for the development of mitochondrial gene therapy system with lower cytotoxicity.

• The Korean Journal of Physiology and Pharmacology
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• 제11권2호
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• pp.57-64
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• 2007

Ischemic preconditioning (IPC) is known to protect the heart against ischemia/reperfusion (IR)-induced injuries, and regional differences in the mitochondrial antioxidant state during IR or IPC may promote the death or survival of viable and infarcted cardiac tissues under oxidative stress. To date, however, the interplay between the mitochondrial antioxidant enzyme system and the level of reactive oxygen species (ROS) in the body has not yet been resolved. In the present study, we examined the effects of IR- and IPC-induced oxidative stresses on mitochondrial function in viable and infarcted cardiac tissues. Our results showed that the mitochondria from viable areas in the IR-induced group were swollen and fused, whereas those in the infarcted area were heavily damaged. IPC protected the mitochondria, thus reducing cardiac injury. We also found that the activity of the mitochondrial antioxidant enzyme system, which includes manganese superoxide dismutase (Mn-SOD), was enhanced in the viable areas compared to the infarcted areas in proportion with decreasing levels of ROS and mitochondrial DNA (mtDNA) damage. These changes were also present between the IPC and IR groups. Regional differences in Mn-SOD expression were shown to be related to a reduction in mtDNA damage as well as to the release of mitochondrial cytochrome c (Cyt c). To the best of our knowledge, this might be the first study to explore the regional mitochondrial changes during IPC. The present findings are expected to help elucidate the molecular mechanism involved in IPC and helpful in the development of new clinical strategies against ischemic heart disease.

• Parasites, Hosts and Diseases
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• 제53권4호
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• pp.421-430
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• 2015

The parasite Plasmodium falciparum causes severe malaria and is the most dangerous to humans. However, it exhibits resistance to their drugs. Farnesyltransferase has been identified in pathogenic protozoa of the genera Plasmodium and the target of farnesyltransferase includes Ras family. Therefore, the inhibition of farnesyltransferase has been suggested as a new strategy for the treatment of malaria. However, the exact functional mechanism of this agent is still unknown. In addition, the effect of farnesyltransferase inhibitor (FTIs) on mitochondrial level of malaria parasites is not fully understood. In this study, therefore, the effect of a FTI R115777 on the function of mitochondria of P. falciparum was investigated experimentally. As a result, FTI R115777 was found to suppress the infection rate of malaria parasites under in vitro condition. It also reduces the copy number of mtDNA-encoded cytochrome c oxidase III. In addition, the mitochondrial membrane potential (${\Delta}{\Psi}m$) and the green fluorescence intensity of MitoTracker were decreased by FTI R115777. Chloroquine and atovaquone were measured by the mtDNA copy number as mitochondrial non-specific or specific inhibitor, respectively. Chloroquine did not affect the copy number of mtDNA-encoded cytochrome c oxidase III, while atovaquone induced to change the mtDNA copy number. These results suggest that FTI R115777 has strong influence on the mitochondrial function of P. falciparum. It may have therapeutic potential for malaria by targeting the mitochondria of parasites.

• 한국어류학회지
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• 제25권3호
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• pp.149-156
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• 2013

우리나라 망둑어과 어류 중 말뚝망둥어아과에 속하며 형태학적으로 흡사한 짱뚱어 (B. pectinirostris)와 남방짱뚱어(S. gigas)를 대상으로 12S rRNA, 16S rRNA 및 mitochondria cytochrome b 유전자의 염기서열 분석을 통해, 종내 및 종간의 분자유전학적 특성을 파악하고자 하였다. 짱뚱어 종내 개체간 유전적 차이를 밝히기 위해 mitochondria내에 3가지 유전자를 분석한 결과, 순천지역과 군산지역간의 염기서열은 12S rRNA는 총 434 bp (base pair)의 염기서열을 얻었으며 이를 비교 분석한 결과, 순천지역과 군산지역의 집단 간에는 100% 동일한 염기서열을 보였고, 16S rRNA 유전자는 총 484 bp의 염기서열 중 99.6%의 차이로 단지 2 bp가 치환된 것으로 나타났고, mitochondria cytochrome b 유전자의 경우, 444 bp의 염기서열을 얻었으며 두 지역 간 염기서열은 100%의 일치도를 보였다. 한국산 짱뚱어를 대상으로 한 동일한 종내에서 서식지 (서해, 남해)에 따른 유전적 차이나 지리적 거리의 차이가 있을 것으로 예상하였으나 이상의 3가지 유전자를 비교해 본 결과를 종합해 보면, 종내 개체 변이와 지역별 변이는 일어나지 않은 것으로 밝혀졌다. 또한 짱뚱어와 남방짱뚱어 2종간 비교 (inter-species)에서는 순천지역 짱뚱어와 해남지역 남방짱뚱어를 12S rRNA 유전자와 16S rRNA 유전자 및 mitochondria cytochrome b 유전자 염기서열을 비교 분석한 결과, 각각 96.1% (17 bp), 94.0 (29 bp), 그리고 82.9% (76 bp)로 나타나 두 종의 유전학적 차이는 크게 나타났다. 따라서 본 연구에서 나타난 짱뚱어와 남방짱뚱어 두 종간에 3.9~17.1%를 보여 서로 다른 종으로 볼 수 있을 것으로 사료되었다.