• BMB Reports
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• 제54권6호
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• pp.305-310
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• 2021

Cereblon (CRBN) is a multi-functional protein that acts as a substrate receptor of the E3 ligase complex and a molecular chaperone. While CRBN is proposed to function in mitochondria, its specific roles are yet to be established. Here, we showed that knockdown of CRBN triggers oxidative stress and calcium overload in mitochondria, leading to disruption of mitochondrial membrane potential. Notably, long-term CRBN depletion using PROteolysis TArgeting Chimera (PROTAC) induced irreversible mitochondrial dysfunction, resulting in cell death. Our collective findings indicate that CRBN is required for mitochondrial homeostasis in cells.

• The Korean Journal of Physiology and Pharmacology
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• 제18권4호
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• pp.297-305
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• 2014

Flavonoids have an ability to suppress various ion channels. We determined whether one of flavonoids, cyanidin-3-glucoside, affects adenosine 5'-triphosphate (ATP)-induced calcium signaling using digital imaging methods for intracellular free $Ca^{2+}$ concentration ([$Ca^{2+}$]i), reactive oxygen species (ROS) and mitochondrial membrane potential in PC12 cells. Treatment with ATP ($100{\mu}M$) for 90 sec induced [$Ca^{2+}$]i increases in PC12 cells. Pretreatment with cyanidin-3-glucoside ($1{\mu}g/ml$ to $100{\mu}g/ml$) for 30 min inhibited the ATP-induced [$Ca^{2+}$]i increases in a concentration-dependent manner ($IC_{50}=15.3{\mu}g/ml$). Pretreatment with cyanidin-3-glucoside ($15{\mu}g/ml$) for 30 min significantly inhibited the ATP-induced [$Ca^{2+}$]i responses following removal of extracellular $Ca^{2+}$ or depletion of intracellular [$Ca^{2+}$]i stores. Cyanidin-3-glucoside also significantly inhibited the relatively specific P2X2 receptor agonist 2-MeSATP-induced [$Ca^{2+}$]i responses. Cyanidin-3-glucoside significantly inhibited the thapsigargin or ATP-induced store-operated calcium entry. Cyanidin-3-glucoside significantly inhibited the ATP-induced [$Ca^{2+}$]i responses in the presence of nimodipine and ${\omega}$-conotoxin. Cyanidin-3-glucoside also significantly inhibited KCl (50 mM)-induced [$Ca^{2+}$]i increases. Cyanidin-3-glucoside significantly inhibited ATP-induced mitochondrial depolarization. The intracellular $Ca^{2+}$ chelator BAPTA-AM or the mitochondrial $Ca^{2+}$ uniporter inhibitor RU360 blocked the ATP-induced mitochondrial depolarization in the presence of cyanidin-3-glucoside. Cyanidin-3-glucoside blocked ATP-induced formation of ROS. BAPTA-AM further decreased the formation of ROS in the presence of cyanidin-3-glucoside. All these results suggest that cyanidin-3-glucoside inhibits ATP-induced calcium signaling in PC12 cells by inhibiting multiple pathways which are the influx of extracellular $Ca^{2+}$ through the nimodipine and ${\omega}$-conotoxin-sensitive and -insensitive pathways and the release of $Ca^{2+}$ from intracellular stores. In addition, cyanidin-3-glucoside inhibits ATP-induced formation of ROS by inhibiting $Ca^{2+}$-induced mitochondrial depolarization.

• BMB Reports
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• 제41권10호
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• pp.745-750
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• 2008

Selenium, an essential trace element possessing anti-carcinogenic properties, can induce apoptosis in cancer cells. We have previously shown that sodium selenite can induce apoptosis by activating the mitochondrial apoptosis pathway in NB4 cells. However, the detailed mechanism remains unclear. Presently, we demonstrate that p53 contributes to apoptosis by directing signaling at the mitochondria. Immunofluorescent and Western blot procedures revealed selenite-induced p53 translocation to mitochondria. Inhibition of p53 blocked accumulation of reactive oxygen species (ROS) and loss of mitochondrial membrane potential, suggesting that mitochondrial p53 acts as an upstream signal of ROS and activates the mitochondrial apoptosis pathway. Selenite also disrupted cellular calcium ion homeostasis in a ROS-dependent manner and increased mitochondrial calcium ion concentration. p38 kinase mediated phosphorylation and mitochondrial translocation of p53. Taken together, these results indicate that p53 involves selenite-induced NB4 cell apoptosis by translocation to mitochondria and activation mitochondrial apoptosis pathway in a transcription-independent manner.

• 대한약리학회:학술대회논문집
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• 대한약리학회 2006년도 58th Annual Meeting of The Korean Society of Pharmacology
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• pp.49-49
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• 2006

• Clinical and Experimental Reproductive Medicine
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• 제50권1호
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• pp.1-11
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• 2023

In reproduction, mitochondria produce bioenergy, help to synthesize biomolecules, and support the ovaries, oogenesis, and preimplantation embryos, thereby facilitating healthy live births. However, the regulatory mechanism of mitochondria in oocytes and embryos during oogenesis and embryo development has not been clearly elucidated. The functional activity of mitochondria is crucial for determining the quality of oocytes and embryos; therefore, the underlying mechanism must be better understood. In this review, we summarize the specific role of mitochondria in reproduction in oocytes and embryos. We also briefly discuss the recovery of mitochondrial function in gametes and zygotes. First, we introduce the general characteristics of mitochondria in cells, including their roles in adenosine triphosphate and reactive oxygen species production, calcium homeostasis, and programmed cell death. Second, we present the unique characteristics of mitochondria in female reproduction, covering the bottleneck theory, mitochondrial shape, and mitochondrial metabolic pathways during oogenesis and preimplantation embryo development. Mitochondrial dysfunction is associated with ovarian aging, a diminished ovarian reserve, a poor ovarian response, and several reproduction problems in gametes and zygotes, such as aneuploidy and genetic disorders. Finally, we briefly describe which factors are involved in mitochondrial dysfunction and how mitochondrial function can be recovered in reproduction. We hope to provide a new viewpoint regarding factors that can overcome mitochondrial dysfunction in the field of reproductive medicine.

• 생명과학회지
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• 제26권11호
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• pp.1232-1236
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• 2016

Mitochondrial calcium uptake 1 (MICU1)은 2개의 canonical EF hands를 가지고 미토콘드리아 내막에 위치하여, 미토콘드리아의 칼슘 섭취에 중요한 기능을 하는 것으로 알려져 있다. 근육 세포의 미토콘드리아 칼슘 섭취는 사후에 급속냉각 또는 냉장 시, 근육 내 칼슘 방출로 인한 강직과 관련되어 있으므로 궁극적으로는 육질 형성에 관련이 있을 것으로 판단된다. 따라서 본 연구에서는 돼지 MICU1 유전자의 exon영역의 변이를 탐색하고, 발굴된 변이에 대해 육질 형질과의 연관성 분석을 실시하였다. 이를 위해 버크셔 667두(암퇘지 347두, 거세수퇘지 320두)가 이용되었으며, MICU1 유전자의 cDNA를 염기서열 해독하여 비교함으로써 exon 영역의 변이를 발굴하였다. 그 결과 MICU1의 3' 비해독 영역(untranslated region, UTR)에서 3개의 단일염기다형성(single-nucleotide polymorphism, SNP)를 발견했다. 그리고 이들 SNP에 대해 공시돈의 육질형질(근육 pH, 육즙 손실, 육색, 근내지방함량)과 연관성 분석을 실시했다. SNP1 (c.*136G>A)에서는 육즙 손실(p=0.017), 근내지방함량(p=0.039)과 연관되어 있었고, SNP2 (c.*222G>A)와 SNP3 (c.*485G>A)에서는 각각 육즙 손실(p=0.018)과 근내지방함량(p<0.001)과 연관되어 있는 것을 확인하였다. 따라서 본 결과를 바탕으로, 돼지에서 육질과 관련된 후보 유전자로 추정된 MICU1 유전자로부터 3' 비해독 영역의 변이가 유의적으로 육질 형질과 관련되어있다는 것이 확인되었다. 향후 MICU1 유전자의 3' 비해독 영역의 변이들에 기능적 역할을 정확히 파악하기 위한 분자생물학적 특성 연구가 필요할 것으로 판단된다.

• Animal Bioscience
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• 제35권10호
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• pp.1616-1627
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• 2022

Objective: This work was conducted to investigate the effects of oxidative stress on meat quality, mitochondrial function, calcium metabolism and ferroptosis of broilers. Methods: In this study, a total of 144 one-day-old male Ross 308 chicks were divided into 3 groups (control group, saline group, and hydrogen peroxide [H₂O₂] group) with 6 replicates of 8 broilers each. The study lasted for 42 d. The broilers in the saline and H₂O₂ groups were intraperitoneally injected with 0.75% saline and 10.0% H₂O₂ on the 16th and 37th day of the experimental period respectively, the injection volumes were 1.0 mL/kg of broiler body weight. On the 42nd day of the experimental period, two chicks were randomly selected from each cage, a total of thirty-six chicks were stunned by electric shock and slaughtered to collect breast muscle samples. Results: The H₂O₂ exposure reduced pH value, increased drip loss and shear force of breast meat (p<0.05), impaired the ultrastructure and function of mitochondria. The H₂O₂ exposure damaged the antioxidant system in mitochondria, excessive reactive oxygen species carbonylation modified calcium channels on mitochondria, which impaired the activities of key enzymes on calcium channel, resulted in the increased calcium concentration in cytoplasm and mitochondria (p<0.05). In addition, the H₂O₂ exposure increased the iron content and lipid peroxidation (p<0.05), which induced ferroptosis. Conclusion: Oxidative stress could impair meat quality by causing mitochondrial dysfunction, resulting in calcium metabolism disorder and ferroptosis.

• BMB Reports
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• 제50권12호
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• pp.597-598
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• 2017

Mitochondria have evolutionarily, functionally and structurally distinct outer- (OMM) and inner-membranes (IMM). Thus, mitochondrial morphology is controlled by independent but coordinated activity of fission and fusion of the OMM and IMM. Constriction and division of the OMM are mediated by endocytosis-like machineries, which include dynamin-related protein 1 with additional cytosolic vesicle scissoring machineries such as actin filament and Dynamin 2. However, structural alteration of the IMM during mitochondrial division has been poorly understood. Recently, we found that the IMM and the inner compartments undergo transient and reversible constriction prior to the OMM division, which we termed CoMIC, ${\underline{C}}onstriction$ ${\underline{o}}f$ ${\underline{M}}itochondrial$ ${\underline{I}}nner$ ${\underline{C}}ompartment$. In this short review, we further discuss the evolutionary perspective and the regulatory mechanism of CoMIC during mitochondrial division.

• Journal of Microbiology and Biotechnology
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• 제31권6호
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• pp.875-881
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• 2021

The mitochondrial targeting domain (MTD) of Noxa contributes to its mitochondrial localization and to apoptosis induction. As a peptide, MTD fused with octa-arginine (R8), a CPP, induces necrosis related to intracellular calcium influx and destruction of mitochondria and endoplasmic reticulum. We searched for homologs of MTD, and compared their cell killing capability when fused with R8. Three of the seven peptides triggered cell death with similar mechanisms. The comparative analysis of peptide sequences showed that four amino acid sites of MTD are critical in regulating necrosis, suggesting the potential to generate artificial, adjustable cytotoxic peptides, which could be effective medicines for many diseases. Thus, homologs functionality could hint to the functions of their belonging proteins.

• Applied Microscopy
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• 제20권1호
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• pp.65-76
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• 1990

The effect of calcium-free reperfusion for 5, 10, and 15 minutes, respectively, followed by continuous reperfusion with normal Tyrode solution containing 1.0mM calcium chloride, after global ischemia in the isolated perfused guinea pig heart by Langendorff techniques was examined with transmission electron microscope. Compared to the nomal Tyrode solution-perfused control hearts, the 5 minute calcium-free-reperfused hearts showed loss or thickening of Z lines, focal sarcolemmal disruption, mitochondrial swelling, clumping of chroma-tin, intracellular fluid accumulation, and some separation of cell junctions, especially the fasciae adherentes. These changes became more severe in the hearts of 10 minute calcium-free reperfusion. Subsarcolemmal larger bleb and near complete separation of cell junctions were noticed. In the 15 minute calcium-free-reperfused hearts, irreversible ultrastructural changes including contraction bands, biazrre mitochondria, and sarcolemmal destruction were widely distributed. The severity of myocardial changes were in accordance with the duration of calcium-free reperfusion. These changes indicate that calcium-free reperfusion regardless of its duration could not salvage the post-ischemic myocardium probably due to development of calcium paradox.