• BMB Reports
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• v.52 no.1
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• pp.64-69
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• 2019

The loss of skeletal muscle, called sarcopenia, is an inevitable event during the aging process, and significantly impacts quality of life. Autophagy is known to reduce muscle atrophy caused by dysfunctional organelles, even though the molecular mechanism remains unclear. Here, we have discuss the current understanding of exercise-induced autophagy activation in skeletal muscle regeneration and remodeling, leading to sarcopenia intervention. With aging, dysregulation of autophagy flux inhibits lysosomal storage processes involved in muscle biogenesis. AMPK-ULK1 and the $FoxO/PGC-1{\alpha}$ signaling pathways play a critical role in the induction of autophagy machinery in skeletal muscle, thus these pathways could be targets for therapeutics development. Autophagy has been also shown to be a critical regulator of stem cell fate, which determines satellite cell differentiation into muscle fiber, thereby increasing muscle mass. This review aims to provide a comprehensive understanding of the physiological role of autophagy in skeletal muscle aging and sarcopenia.

• BMB Reports
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• v.56 no.2
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• pp.90-95
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• 2023

Mitochondria are important organelles that regulate adenosine triphosphate production, intracellular calcium buffering, cell survival, and apoptosis. They play therapeutic roles in injured cells via transcellular transfer through extracellular vesicles, gap junctions, and tunneling nanotubes. Astrocytes can secrete numerous factors known to promote neuronal survival, synaptic formation, and plasticity. Recent studies have demonstrated that astrocytes can transfer mitochondria to damaged neurons to enhance their viability and recovery. In this study, we observed that treatment with mitochondria isolated from rat primary astrocytes enhanced cell viability and ameliorated hydrogen peroxide-damaged neurons. Interestingly, isolated astrocytic mitochondria increased the number of cells under damaged neuronal conditions, but not under normal conditions, although the mitochondrial transfer efficiency did not differ between the two conditions. This effect was also observed after transplanting astrocytic mitochondria in a rat middle cerebral artery occlusion model. These findings suggest that mitochondria transfer therapy can be used to treat acute ischemic stroke and other diseases.

• Current Optics and Photonics
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• v.7 no.1
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• pp.65-72
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• 2023

The motion of organelles inside a cell is an important intrinsic indicator for assessing cell physiology and tissue viability. Dynamic contrast full-field optical coherence tomography (D-FFOCT) is a promising imaging technology that can visualize intracellular movements using the variance of temporal interference signals caused by biological motions. However, double-path interferometry in D-FFOCT can be highly vulnerable to surrounding noise, which may cause turbulence in the interference signals, contaminating the sample dynamics. Therefore, we propose a method for stabilized D-FFOCT imaging in noisy environments by using common-path interferometry in D-FFOCT. A comparative study shows that D-FFOCT with the proposed method achieves stable dynamic contrast imaging of a scattering phantom in motion that is over tenfold more noise-insensitive compared to the conventional one, and thus this imaging capability can provide cleaner motion contrast images. With the proposed approach, the intracellular dynamics of biological samples are imaged and monitored.

• Applied Microscopy
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• v.20 no.1
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• pp.36-50
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• 1990

This experiment was performed to study the morphological responses of the enterochromaffin cells in the duodenal mucosa of rabbit following bile duct ligation. Adult male rabbits were divided into normal, sham operation and experimental groups. Bile duct ligation was performed under ether anesthesia and animals were sacrificed on the 1st, 3rd, 5th, 7th and 14th day after operation. Mucosal specimens from the duodenum were prefixed with 2.5% glutaraldehyde-1.5% paraformaldehyde(0.1M Millonig's phosphate buffer, pH 7.3), followed by postfixation with 1% osmium tetroxide(0.1M Millonig's phosphate buffer, pH 7.3), and embedded within araldite mixture. The sections were cut on a LKB-V ultratome, and observed under a JEM 100CX II electron miroscope. The results were as follow; 1. Irregularities of the nuclei of the enterochromaffin cells were noticed from the 1st day after bile duct ligation, and concentration of the chromatin in the nucleus was more frequently observed on the 7th and the 14th day. 2. The granular endoplasmic reticulum and Golgi complex of the enterochromaffin cell were more developed than those of the normal on the 1st day after bile duct ligation, but they showed poor organization from the 3rd day. 3. Amount of the microfilaments in the enterochromaffin cell was significantly increased from the 5th day after bile duct ligation and they were more frequently observed in the vicinity of the nucleus. 4. Vacuoles with various electron densities in the enterochromaffin cell were increased in number from the 3rd day after bile duct ligation. 5. Glycogen-like particles in the enterochromaffin cell were frequently observed on the 3rd and the 5th day after bile duct ligation. 6. In the early stage of the ligation of bile duct, in the enterochromaffin cells, well developed intracellular organelles, such as granular endoplasmic reticulum and Golgi apparatus were pronounced. But, in the later stage, the cells contained poor organelles, with the some structural sign of necrotic change.

• Applied Microscopy
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• v.12 no.1
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• pp.57-68
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• 1982

Cyclical changes in the fine structures of endometrial stroma of guinea pig during the estrous cycle were studied by electron microscopy. Cytochemical studies were made in order to investigate the ultrastructural localization of the acid phosphatase,alkaline phosphatase and ATPase in these cells. The results obtained are as follows: 1. During estrus collagen fibers were most abundant in the stroma. The stromal cells showed increases in the number of several cytoplasmic organelles, especially the rough endoplasmic reticulum was significantly increased and the structures were greatly differentiated. 2. Many cytoplasmic processes and cell debris have been distributed in the stroma of metestrus. The distributions were increased and degenerated mitochondria were observed during diestrus. 3. Cytochemical studies indicated that during metestrus and diestrus acid phosphatase activities were localized in the degenerating collagen fibers. Alkaline phosphatase activities were weak in the collegen fibers during proestrus and estrus which intense activities were localized around the cell membrane during metestrus and diestrus. ATPase activities were present on the cell membrane and intercellular space of stromal cell during proestrus and estrus.

• Korean Journal of Microbiology
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• v.22 no.1
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• pp.19-28
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• 1984

The nematode-trapping process by Arthrobotrys conoides was investigated with the aid of scanning and transmission electron microscopy. 1. A. conoides captures nematode by means of three-dimensional network. 2. The wall of trap cell was thicker than that of vegetative hypha and the trap cell was more rich in cell organelles such as endoplasmic reticulum, mitochondria and electrondense granule. 3. The electron-dense granule, which could be found only in trap organs, gradually disappeared during its penetration into nematode cuticle. 4. The osmiophilic area was found at adhering site between the trap organ and nematode cuticle. 5. In some cases, any appressorium was not found at the site of penetration. 6. When the fungal-nematode culture was conserved for 2~3 weeks, numerous young nematodes were found to be adhered to spores, resulting in death.

• The Journal of Korean Obstetrics and Gynecology
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• v.28 no.2
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• pp.1-14
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• 2015

Objectives : This study was designed to investigate the effects of Taraxaci Herba (TH) on cell death in breast cancer cells. Methods : In this experiment, the effects of TH on proliferation rates, cell morphology and growth pattern, intracellular reactive oxygen species (ROS) production. In addition, the effects on nuclear condensation, fragmentation and formation of acidic vesicular organelles (AVO) in MCF-7 cells were also investigated. Finally, autophagy related with protein was observed by using western blot method. Results : TH inhibited proliferation of MCF-7 cells, TH elevated intracellular ROS levels significantly. Treatment with TH did not affect nuclear morphologies such as condensation or fragmentation. On the other hand, TH treatment effectively induced AVO. Finally, one of autophagy related with protein, Microtubule-associated proteins 1A/1B light chain 3A (MAP1LC3A, LC3) level was elevated by treatment with TH. Conclusions : These data indicate that TH is able to be used for patient with breast cancer and mechanisms are involved in autophagy through ROS generation.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1364-1368
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• 2009

Lysosomes, as a cell organelle type, are safe biological control agents that may be possible replacements for chemical antimicrobial agents because they are simply isolated from egg white. In this study, it was found that the lysosomes isolated from egg white exhibited pH-dependent antimicrobial activity, with the optimal activity found at pH 6.0. The efficiency of lysosomes in inhibiting bacterial growth and activity was evaluated over a 12-h treatment period. Seven different microorganisms were used as bacterial strains, and the lysosomes showed a significant antimicrobial effect against all strains. In addition, the antimicrobial activity was maintained for 100 days, and there did not appear to be any resistance of E. coli to the lysosomal activity up to the eighth culture. However, the lysosomes did not affect the viability of mammalian cells, suggesting the biocompatibility of lysosomes. These highly effective lysosomes have a bright future in the application of novel antimicrobial sources as a cell organelle type.

• Applied Microscopy
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• v.29 no.4
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• pp.417-426
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• 1999

The present investigation is designed to provide basic information on fine structure of the skin of the sea bass, Lateolabrax japonicks in relation to study of epidermal change with environmental and physiological change. The skin of the sea bass is divided into the epidermal layer and dermal layer. Epidermal layer consists of supporting cells and unicellular glands. The supporting cells were classified into the superficial cell, intermediated cell and basal cell. Gland cells were classified into the mucous secretory cell and club cell which is more frequently observed. Superficial cell of epidermal layer is squamous or cuboidal and contains well-developed rough endoplasmic reticulum and the surface is covered with numerous microridges. Superficial cells are connected to another cell with membrane interdigitations and desmosomes. Intermediated cell is ovoid and the electron density is higher than the other supporting cells. Basal cell is cuboidal and has a well-developed mitochondria and membrane interdigitation. The mucous secretory cell has a numerous membrane bounded secretory granules. The cytoplasm of club cell is divided into cortex and medullar. The medullar cytoplasm has a nucleus, intracellular organelles and central vacuole, and the cortical cytoplasm has a well-developed tonofilament. Club cells are connected to another cell with well -developed membrane interdigitations and desmosomes.

• The Korean Journal of Zoology
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• v.28 no.1
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• pp.44-59
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• 1985

The epithelium of the hindgut in the german cockroach, Blattella germanica Linne, was observed with electron microscope. The epithelium of the ileum, which is located at the anterior hindgut, is composed of a single layer of squamous and cuboidal cells. The liminal surface of the epithelium is lined with the cuticular intima. The epithelial cells contain cell organelles expected to be found in absorptive cells, and some epithelial cells have numerous lamelated crystals, the "spherites". The rectal epithelium of posterior hindgut is composed of rectal pads which are covered with cuticular intima on the luminal side. The rectal pads are composed of columnar absorptive cells and basal cells. The apical plasma membrane of columnar cell is made of microvilli, where mitochondria associated with some of the microvilli. The lateral plasma membrane is highly infolded and space is an uniform width of approximately 200$\\AA$. Well developed mitochondria are found closely associated with the infoldings and this is referred to as the "mitochondrial-scalariform complex". A septate junction is found near the apical zone between the columnar absorptive cells, whereas many desmosomes and intercellular spaces are formed between the columnar cells. Basal cells are bowl-shaped where the convex surface is inlaid into the basal surface of the columnar cells while the concave surface faces the basal lamina. The cytoplasm of the basal cell is electron dense and contains well developed cell organelles. The basal sheath is located between the basal membrane and basal lamina, providing barrier between the epithelium and the hemolymph. The epithelium is surrounded by the subepithelial space and muscles. The subepithelial space, which is composed of fibrous connective tissue, is innervated by many tracheoles and axons.