• Journal of Microbiology and Biotechnology
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• 제19권11호
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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.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.372-379
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• 2017

The transport of lysosomal enzymes into the lysosomes depends on the phosphorylation of their chains and the binding of the phosphorylated residues to mannose-6-phosphate receptors. The efficiency of separation depends more on the phosphodiesterases (PDEs) than on the activity of the phosphorylation of mannose residues and can be determined in vitro. PDEs play important roles in regulation of the activation of lysosomes. The expression of proteins was confirmed by western blotting. All PDE4 series protein expression was reduced in high concentrations of rolipram. As a result of observing the fluorescence intensity after rolipram treatment, the lysosomal enzyme was activated at low concentrations and suppressed at high concentrations. High concentrations of rolipram recovered the original function. Antimicrobial activity was not shown in either 10 or $100{\mu}M$ concentrations of rolipram in treated HeLa cells in vitro. However, the higher anticancer activity at lower rolipram concentration was shown in lysosomal enzyme treated with $10{\mu}M$ of rolipram. The anticancer activity was confirmed through cathepsin B and D assay. Tranfection allowed examination of the relationship between PDE4 and lysosomal activity in more detail. Protein expression was confirmed to be reduced. Fluorescence intensity showed decreased activity of lysosomes and ROS in cells transfected with the antisense sequences of PDE4 A, B, C, and D. PDE4A showed anticancer activity, whereas lysosome from cells transfected with the antisense sequences of PDE4 B, C, and D had decreased anticancer activity. These results showed the PDE4 A, B, C, and D are conjunctly related with lysosomal activity.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.234-237
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• 2015

In this study, we developed lysosome-alginate beads for application as an oral drug delivery system (ODDS). The beads harboring lysosomes, which have antimicrobial activity, and various concentrations of alginate were characterized and optimized. For application as an ODDS, pH-dependent lysosome-alginate beads were generated, and the level of lysosome release was investigated by using antimicrobial tests. At low pH, lysosomes were not released from the lysosome-alginate beads; however, at neutral pH, similar to the pH in the intestine, lysosome release was confirmed, as determined by a high antimicrobial activity. This study shows the potential of such an ODDS for the in vivo treatment of infection with pathogens.

• Molecules and Cells
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• 제41권1호
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• pp.45-49
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• 2018

Autophagy is a lysosome-dependent degradation process that is essential for maintaining cellular homeostasis. In recent years, more studies have focused on the late stages of autophagy. Our group discovered and studied the terminal step of autophagy, namely autophagic lysosome reformation (ALR). ALR is the process that regenerates functional lysosomes from autolysosomes, thus maintaining lysosome homeostasis. ALR involves clathrin-mediated membrane budding from autolysosomes, elongation of membrane tubules along microtubules with the pulling force provided by the motor protein KIF5B, proto-lysosome scission by dynamin 2, and finally maturation of proto-lysosomes to functional lysosomes. In this review, we will summarize progress in unveiling the molecular mechanisms underlying ALR and its potential pathophysiological roles.

• Applied Microscopy
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• 제28권4호
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• pp.551-561
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• 1998

The autometallographic method was used to demonstrate the localization of mercury deposits in spleen of mouse. The mercury deposits were identified with the light and electron mocroscope. Mice were treated with methylmercuric chloride in the drinking water (demineralized water) for 40 days. Control and mercury treated groups showed no significant differences in mean body weight and spleen weight per one mouse. Mercury grains were appeared in the germinal center of white pulp consist of a preponderancing lymphocytes, not in red pulp and capsule. At the ultrastructural level, mercury deposits were restricted to lysosomes of macrophage and lymphocyte. Specially, volume in lysosomes of the macrophage was increased. These results suggest that mercury localization in lysosomes is associated with the change of immune activity.

• Molecules and Cells
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• 제45권9호
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• pp.649-659
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• 2022

A long-term energy nutritional imbalance fundamentally causes the development of obesity and associated fat accumulation. Lysosomes, as nutrient-sensing and lipophagy centers, critically control cellular lipid catabolism in response to nutrient deprivation. However, whether lysosome activity is directly involved in nutrient-induced fat accumulation remains unclear. In this study, worm fat accumulation was induced by 1 mM glucose or 0.02 mM palmitic acid supplementation. Along with the elevation of fat accumulation, lysosomal number and acidification were also increased, suggesting that lysosome activity might be correlated with nutrient-induced fat deposition in Caenorhabditis elegans. Furthermore, treatments with the lysosomal inhibitors chloroquine and leupeptin significantly reduced basal and nutrient-induced fat accumulation in C. elegans. The knockdown of hlh-30, which is a critical gene in lysosomal biogenesis, also resulted in worm fat loss. Finally, the mutation of aak-2, daf-15, and rsks-1 showed that mTORC1 (mechanistic target of rapamycin complex-1) signaling mediated the effects of lysosomes on basal and nutrient-induced fat accumulation in C. elegans. Overall, this study reveals the previously undescribed role of lysosomes in overnutrition sensing, suggesting a new strategy for controlling body fat accumulation.

• 생명과학회지
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• 제31권5호
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• pp.527-535
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• 2021

라이소좀은 산성가수분해 효소를 가진 세포 내 소기관으로 단백질 및 고분자를 분해한다. 영양분 상태에 따라 세포 내 다양한 신호 전달 경로를 조절하는 신호 경로 중추로, 세포 항상성 조절에 중요한 역할을 한다. 따라서 이러한 라이소좀의 기능 이상은 라이소좀 저장질환, 퇴행성 신경질환 및 암을 발생시킬 수 있다. 암세포에서는 다양한 자극에 의한 lysosomal membrane permeabilization (LMP)가 일어날 수 있으며, 카텝신과 같은 라이소좀 내 효소 및 내용물이 세포질로 유출되어 다양한 형태의 라이소좀 의존적인 암세포사멸을 유도한다. 본 보고에서는 LMP 증가를 통한 다양한 형태의 세포사멸 유도 기전 및 항암제 민감성 증진에 대해 서술하였다. 미미한 LMP 유도는 일부 카텝신이 세포질로 유출되어 전형적인 세포사멸(apoptosis)을 일으키는 반면 강력한 LMP 유도는 라이소좀의 파열로 많은 카텝신 및 활성산소의 유출로 non-apoptotic 세포사멸을 일으킨다. 이러한 LMP 유도는 라이조솜 내에 포획된 항암제가 세포질로 유출되어 다른 타겟 소기관으로 작용하여 항암제에 대한 내성을 극복하고 민감성을 증진시킬 수 있다. 따라서, LMP 유도제 및 라이소좀 항성 작용제(lysosomotropic agent)에 의한 라이소좀 막 분열은 종양치료에 있어 새로운 전략이 될 수 있다.

• BMB Reports
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• 제41권12호
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• pp.827-832
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• 2008

Many age-dependent neurodegenerative diseases are associated with the accumulation of abnormally folded proteins within neurons. One of the major proteolytic pathways in the cell is the autophagy pathway, which targets cytoplasmic contents and organelles to the lysosomes for bulk degradation under various physiological and stressful conditions. Although the importance of autophagy in cellular physiology is well appreciated, its precise roles in neurodegeneration remain largely unclear. Recent studies indicate that components of the endosomal sorting complex required for transport (ESCRT) are important in the autophagy pathway. Reduced activity of some ESCRT subunits leads to the accumulation of autophagosomes and failure to clear intracellular protein aggregates. Interestingly, rare mutations in CHMP2B, an ESCRT-III subunit, are associated with frontotemporal dementia linked to chromosome 3 (FTD3). Mutant CHMP2B proteins seem to disrupt the fusion of autophagosomes and lysosomes in cell culture models. These findings suggest a potential mechanism for the pathogenesis of FTD3 and possibly other neurodegenerative diseases as well.

• 한국동물학회지
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• 제21권3호
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• pp.87-102
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• 1978

수은이 붕어(Carassius carassius L.)의 간, 신장 아가미에 미치는 영향을 규명하기 위하여 붕어를 1 ppm, 2.5 ppm 농도의 $HgCl_2$에 노출시킨 후 전자현미경을 사용하여 그들의 미세구조 변화에 대한 연구를 수행한 바 다음과 같은 결과를 얻었다. 1. 수은에 처리된 간세포에서는 lysosome이 증가하였으며 결정상의 구조물들을 포함한 원형의 lysosome과 히ㅛ\ulcorner두과립이나 mitochondria를 탐식한 lysosome의 2가지 형태가 관찰되었고 mitochondria는 팽대되어 내부 기질의 전자밀도가 감소되었으며 핵에서는 인의 분리현상이 관찰되었다. 2. 신장의 변화로서는 신사구체 기저막의 비후와 기부선회소관에서는 공포들의 증가와 cytoplasmic body들이 출현하였으며 공포형성은 mitochondria와 연관되어 일어났다. 또한 2.5 ppm에서는 핵의 위축이 관찰되었다. 3. Gill lamella의 상피세포에서는 대, 소형의 lysosome이 증가했으며 lamella의 막에 fuzzy한 구조가 관찰되었다. 4. 본 실험에서 관찰된 결과로써 수은에 의해 초래된 세포의 미세구조의 변화는 세포의 해독과정을 활성화시키며 energy대사과정을 손상시키는 것으로 생각된다.

• The Korean Journal of Physiology and Pharmacology
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• 제27권4호
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• pp.311-323
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• 2023

Ion homeostasis, which is regulated by ion channels, is crucial for intracellular signaling. These channels are involved in diverse signaling pathways, including cell proliferation, migration, and intracellular calcium dynamics. Consequently, ion channel dysfunction can lead to various diseases. In addition, these channels are present in the plasma membrane and intracellular organelles. However, our understanding of the function of intracellular organellar ion channels is limited. Recent advancements in electrophysiological techniques have enabled us to record ion channels within intracellular organelles and thus learn more about their functions. Autophagy is a vital process of intracellular protein degradation that facilitates the breakdown of aged, unnecessary, and harmful proteins into their amino acid residues. Lysosomes, which were previously considered protein-degrading garbage boxes, are now recognized as crucial intracellular sensors that play significant roles in normal signaling and disease pathogenesis. Lysosomes participate in various processes, including digestion, recycling, exocytosis, calcium signaling, nutrient sensing, and wound repair, highlighting the importance of ion channels in these signaling pathways. This review focuses on different lysosomal ion channels, including those associated with diseases, and provides insights into their cellular functions. By summarizing the existing knowledge and literature, this review emphasizes the need for further research in this field. Ultimately, this study aims to provide novel perspectives on the regulation of lysosomal ion channels and the significance of ion-associated signaling in intracellular functions to develop innovative therapeutic targets for rare and lysosomal storage diseases.