• Animal cells and systems
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• v.16 no.4
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• pp.269-273
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• 2012

Controlling metabolism throughout life is a necessity for living creatures, and perturbation of energy balance elicits disorders such as type-2 diabetes mellitus and cardiovascular disease. $Ca^{2+}$ plays a key role in regulating energy generation. $Ca^{2+}$ homeostasis of the endoplasmic reticulum (ER) lumen is maintained through the action of $Ca^{2+}$ channels and the $Ca^{2+}$ ATPase pump. Once released from the ER, $Ca^{2+}$ is taken up by mitochondria where it facilitates energy metabolism. Mitochondrial $Ca^{2+}$ serves as a key metabolic regulator and determinant of cell fate, necrosis, and/or apoptosis. Here, we focus on $Ca^{2+}$ transport from the ER to mitochondria, and $Ca^{2+}$-dependent regulation of mitochondrial energy metabolism.

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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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.

• Molecules and Cells
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• v.43 no.1
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• pp.10-22
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• 2020

Mitochondria have several quality control mechanisms by which they maintain cellular homeostasis and ensure that the molecular machinery is protected from stress. Mitophagy, selective autophagy of mitochondria, promotes mitochondrial quality control by inducing clearance of damaged mitochondria via the autophagic machinery. Accumulating evidence suggests that mitophagy is modulated by various microbial components in an attempt to affect the innate immune response to infection. In addition, mitophagy plays a key role in the regulation of inflammatory signaling, and mitochondrial danger signals such as mitochondrial DNA translocated into the cytosol can lead to exaggerated inflammatory responses. In this review, we present current knowledge on the functional aspects of mitophagy and its crosstalk with innate immune signaling during infection. A deeper understanding of the role of mitophagy could facilitate the development of more effective therapeutic strategies against various infections.

• Molecules and Cells
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• v.41 no.12
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• pp.1000-1007
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• 2018

Mitochondria and endoplasmic reticulum (ER) are essential organelles in eukaryotic cells, which play key roles in various biological pathways. Mitochondria are responsible for ATP production, maintenance of $Ca^{2+}$ homeostasis and regulation of apoptosis, while ER is involved in protein folding, lipid metabolism as well as $Ca^{2+}$ homeostasis. These organelles have their own functions, but they also communicate via mitochondrial-associated ER membrane (MAM) to provide another level of regulations in energy production, lipid process, $Ca^{2+}$ buffering, and apoptosis. Hence, defects in MAM alter cell survival and death. Here, we review components forming the molecular junctions of MAM and how MAM regulates cellular functions. Furthermore, we discuss the effects of impaired ER-mitochondrial communication in various neurodegenerative diseases.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.293-295
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• 1998

• Journal of Sericultural and Entomological Science
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• v.42 no.1
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• pp.58-64
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• 2000

This study was designed to investigate the effects of silk fibroin powder (Mw 500) on oxidative stress and membrane fluidity in liver membranes of rats. Sprague-Dawley (SD) male rats (160$\pm$10g) were fed basic diet (control group), and experimental diets (SEP-2.5 and SFP-5.0 groups) added 2.5 and 5.0 g/kg BW/day for 6 weeks. Cholesterol levels resulted in a significant decrease (12.1% and 9.0%, respectively) in the liver mitochondria and microsomes of SEP-5.0 group compared with control group. Membrane fluidity as significantly increased (16.1% and 16.5%, 5.8% and 17.4%) in the liver mitochondria and microsomes were significantly inhibited (16.1% and 18.3%, 8.1% and 15.1%, respectively) at the SFP-2.5 and SEP-5.0 groups compared with control group. Induced oxygen radicals (BOR) in liver mitochondria and microsomes were significantly inhibited (16.1% and 18.3%, 8.1% and 15.1%, respectively) at the SFP-2.5 and SEP-5.0 groups compared with control group. Induced oxygen radicals (IOR) in liver microsomes were significantly inhibited (17.0% and 26.6%, respectively) at the SFP-2.5 and SFP-5.0 groups compared with control group, but IOR in liver mitochondria was significantly inhibited about 12.3% at the SWP-400 group only compared with control group. Lipid peroxide (LPO) levels were significantly decreased (8.3% and 18.0%, 13.4% and 18.4%, respectively) in the liver mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. Oxidized protein (OP) levels were dose-dependently decreased (5.4% and 11.6%, 19.0% and 24.4%, respaectively) in the iver mitochondria and microsomes of SFP-2.5 and SFP-5.0 groups compared with control group. These results suggest that administration of SFP may play an effective role in attenuating an oxidative stress and increasing a membrane fluidity in liver membranes.

• Applied Microscopy
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• v.23 no.1
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• pp.15-24
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• 1993

The toxic effects of methylmercury on the ultrastructures of the brain and gill tissues of fightingfish and compensative effects of red ginseng were investigated by means of electron microscopy. The brain neuron of methylmercury exposure group showed dilatation of dendrite and axon, numerical decrease of ribosomes, partial loss of nucleoplasm and cytoplasm and considerable swelling of mitochondria as compared with the normal neuron. And necrotic cell with ruptured nucleus and vacuolated mitochondria was noticeable. While, slight swelling of mitochondria, some dilation of dendrite and axon and numerical increase of ribosome occurred in the neuron of methylmercury-red ginseng treatment group as compared with the methylmercury exposure group. In the gill lamella of methylmercury exposure group, collapse of pillar cells and arms, dilated epithelial cell and thickened membrane were observed. While, in the gill lamella of methylmercury-red ginseng treatment group, arms were slightly disintegrated and basement membrane was some thickend as compared with the methylmercury exposure group. From the above results, it is concluded that red ginseng has detoxication effect on methylmercury toxicity and so takes compensative effect on injured tissues caused by methylmercury intoxication.

• The Korean Journal of Malacology
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• v.27 no.1
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• pp.69-76
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• 2011

Gill morphology and ultrastructure of the spiny top shell, Batillus cornutus were described using light and electron microscopy (SEM and TEM). The spiny top shell, Batillus cornutus has bipectinate gill. The epithelial layer of gill filament was simple and composed of columnar epithelium, ciliated cell, mitochondria-rich cell and secretory cell. Microvilli were well-developed on the free surface of columnar epithelial cell. The epithelial cells are connected to the neighboring cells with intercelluar junctions at the apico-lateral surface. The cilia and microvilli were commonly observed on the free surface of ciliated cell. Tubular mitochondria appeared in the apical cytoplasm, and connected ciliary rootlet. Mitochondria-rich cells contained a oval-shaped nucleus in the basal area. And majority of cytoplasm was occupied by well-developed mitochondria. Result of AB-PAS (pH 2.5) and AF-AB reaction showed that secretory cells contained mainly acidic carboxylated mucosubstances. Secretory cells are unicellular glands and can be divided into four types (A, B, C and D) depending on the cell shape and ultrastructure of secretory granules.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.249-253
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• 2008

Since there is no report about more than one gene expression simultaneously in a single mitochondria, this report is very important to novel type of eukaryotic gene expression. In this study, investigated whether mitochondrial expressed gene and GFP that expression in mitochondria of plant expressed to mitochondria. Expression vector (pBin) containing AtBI-1 (mitochondrial expressed gene) and GFP driven by 35S promoter was bombarded by gene gun to leaves and cotyledon of tobacco. Regenerated shoot confirmed expression of AtBI-1 in mitochondria by GFP expression, PCR, and Southern analysis. Successful mitochondria of plant cell transformation in this report implies possible eukaryotic mitochondrial transformation including plants and animals, and moreover two or more gene expression which can be excellent applicable protocols to pharmaceutical field including antibody production.

• Applied Biological Chemistry
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• v.28 no.4
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• pp.271-277
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• 1985

A polarograph with specially designed cell compartment usable in kinetic study of the mitochondrial respiration of a small sized sample was made, and its performance and experimental conditions were examined. An applied potential (ca-1.2V vs. SCE) which gives rise to the second step reduction of oxygen caused a considerable level of a residual current independent of oxygen, which is temporarily interpreted as the reduction current of the membrane-bound redox material(s) of mitochondria. A potential corresponding to the first slop reduction of oxygen (ca-0.4V vs SCE) did not produce the residual current. Thus, it is suggested that a measurement of oxygen concentration in a sample of mitochondria and submitochondrial particles by using dropping mercury electrode should be done with an applied potential of about -0.4V vs SCE. Consumption of oxygen by mitochondria was observed to follow practically zero order kinetics. Its rate constant exhibited the proportional relationship with the respiratory activity of mitochondria. Usefulness of tile instrument was properly demonstrated in the work on the temperature effect on the respiration of mitochondria isolated from several plant 4issues which were selected on the basis of chilling susceptivity.