• Integrative Medicine Research
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• v.6 no.4
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• pp.452-456
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• 2017

Everything in the surrounding universe can be attributed into five elements. Human organs can be also linked to the five elements. Cells, the smallest unit of the human body, consist of cellular organelles as little organs. Here, we extended the concept of the five elements to a cellular level via the human organs, theoretically re-evaluating the overall association of cellular organelles in maintaining the homeostasis of cellular functions.

• Analytical Science and Technology
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• v.28 no.1
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• pp.65-71
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• 2015

Intracellular organelles in eukaryotic cells play important roles in many cellular functions. Intracellular trafficking of many proteins to specific intracellular organelles is tightly regulated by various mechanisms in cells. Therefore, elucidating the targeting mechanism of novel markers for intracellular organelles is important for cellular physiology and pathology. In this study, we tried to identify the peptides which could bind to specific glycolipid in cellular membrane using GFP-fused glycolipid-binding peptides, and analyzed their cellular localization. As a result, we could identify mitochondria-, Golgi- or plasma membrane-targeting peptides. Furthermore, we found that the plasma membrane-targeting peptide was localized to the plasma membrane via electrostatic interactions. Thus, our results suggest that various glycolipid-binding peptides could be used as intracellular organelles markers.

• Molecules and Cells
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• v.44 no.11
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• pp.851-860
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• 2021

Label-free optical diffraction tomography (ODT), an imaging technology that does not require fluorescent labeling or other pre-processing, can overcome the limitations of conventional cell imaging technologies, such as fluorescence and electron microscopy. In this study, we used ODT to characterize the cellular organelles of three different stem cells-namely, human liver derived stem cell, human umbilical cord matrix derived mesenchymal stem cell, and human induced pluripotent stem cell-based on their refractive index and volume of organelles. The physical property of each stem cell was compared with that of fibroblast. Based on our findings, the characteristic physical properties of specific stem cells can be quantitatively distinguished based on their refractive index and volume of cellular organelles. Altogether, the method employed herein could aid in the distinction of living stem cells from normal cells without the use of fluorescence or specific biomarkers.

• Molecules and Cells
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• v.43 no.8
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• pp.686-693
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• 2020

Autophagy is an intracellular degradation system that breaks down damaged organelles or damaged proteins using intracellular lysosomes. Recent studies have also revealed that various forms of selective autophagy play specific physiological roles under different cellular conditions. Lipid droplets, which are mainly found in adipocytes and hepatocytes, are dynamic organelles that store triglycerides and are critical to health. Lipophagy is a type of selective autophagy that targets lipid droplets and is an essential mechanism for maintaining homeostasis of lipid droplets. However, while processes that regulate lipid droplets such as lipolysis and lipogenesis are relatively well known, the major factors that control lipophagy remain largely unknown. This review introduces the underlying mechanism by which lipophagy is induced and regulated, and the current findings on the major roles of lipophagy in physiological and pathological status. These studies will provide basic insights into the function of lipophagy and may be useful for the development of new therapies for lipophagy dysfunction-related diseases.

• 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.

• Biomedical Science Letters
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• v.2 no.2
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• pp.159-166
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• 1996

In order to investigate the recycling of the pulmonary surfactant in association with morphological changes in macrophage after interleukin-1 $\alpha$ (IL-1) induced lung injury, an acute lung injury was induced by instillation of IL-1 into the trachea. Numbers of neutrophils and phospholipid content were increased significantly(P<0.01) in IL-1 treated BAL(brochoalveolar lavage) compared to control rat. By increased phagocytosis, the lamellar structures in the macrophges of IL-1 treated rats' BAL were increased and the compositions of the cellular organelles were changed in comparison to control rat. This difference in compositions of cellular organelles denotes difference of functions in macrophages between control and IL-1 treated rats. As macrophages have been said to implicate (in the difference in the recycling of pulmonary surfactant, it is highly probable that the difference in compositions of cellular organelles is closely related to the recycling of pulmonary surfactant. In the present study circular structures were synthesized in the cytoplasm of the macrophages in BAL of normal rats. Based on these experimental results, it is suggested that macrohages might synthesize during recycling of surfacuant in the lung.

• Journal of Plant Biology
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• v.34 no.1
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• pp.1-8
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• 1991

A sequential sub-cellular study of the epicarp of Nerium indicum has been performed. Outer epidermis of the ovary wall is covered externally with a thin cuticle. Cytoplasm possesses most of the cell organelles in the ovary stage itself. Outermost zone of the pericarp is the epicarp, developing from the outer epidermis. In the developing fruit, cell organelles are found with its maximum intensity. In mature fruit, the epicarp becomes multilayered due to additional development of few collenchymatous cells close to the outermost layer. Epicarpic cell possesses large central vacuole, around which a thin layer of cytoplasm is present. Number of cell organelles are considerably reduced in the mature fruit. In the ovary stage starch grains are electron transparent, while in the mature fruit it is fruit it is electron transluscent.

• BMB Reports
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• v.50 no.1
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• pp.5-11
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• 2017

One of the characteristics of the neurons that distinguishes them from other cells is their complex and polarized structure consisting of dendrites, cell body, and axon. The complexity and diversity of dendrites are particularly well recognized, and accumulating evidences suggest that the alterations in the dendrite structure are associated with many neurodegenerative diseases. Given the importance of the proper dendritic structures for neuronal functions, the dendrite pathology appears to have crucial contribution to the pathogenesis of neurodegenerative diseases. Nonetheless, the cellular and molecular basis of dendritic changes in the neurodegenerative diseases remains largely elusive. Previous studies in normal condition have revealed that several cellular components, such as local cytoskeletal structures and organelles located locally in dendrites, play crucial roles in dendrite growth. By reviewing what has been unveiled to date regarding dendrite growth in terms of these local cellular components, we aim to provide an insight to categorize the potential cellular basis that can be applied to the dendrite pathology manifested in many neurodegenerative diseases.

• Applied Microscopy
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• v.39 no.2
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• pp.185-189
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• 2009

Studies about the structure of Drosophila melanogaster retinal cell using electron microscopy have been carried out in details since 1960s. However, these results can have limitations in functional research because of two-dimensional structure. In this study, the adult retina of Drosophila melanogaster was investigated by employing high pressure freezing method, serial sections, high voltage electron microscopy, and 3-dimensional reconstruction method. From there results, mitochondria, microtubules, and nuclei were reconstructed as 3-dimensional structure using IMOD program. The 3D structure of these organelles showed that mitochondira mainly located in distal region near lens, and microtubule mainly located in distal and basal region. The 3D reconstruction of these organelles can be used for a critical evaluation in the dynamic change of cellular organelles caused by functional abnormality like retinal degeneration.

• Applied Microscopy
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• v.27 no.2
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• pp.165-175
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• 1997

This paper aims to prove the effects of Squalene (SQ) on the cellular toxicity of 5-FU to the mouse which pretreated with SQ and then treated with 5-FU. The results of the group A (treated with only 5-FU) are as follows. The nucleus was destroyed at 24 hours and 48 hours group, however, somewhat repaired at 72 hours group. The dilated inner cavity and the irregular lamellae of the rough surfaced endoplasmic reticulum (RER) were observed continually until 72 hours group. The inner cavity of the smooth surfaced endoplasmic reticulum (SER) were dilated in all groups. However, the destroyed and the normal membrane were observed simultaneously at 72 hours group. The inner membrane of the mitochondria were almost repaired at 96 hours group. The results of the group B (treated with 5-FU and squalene) are as follows. The nucleus was a little influenced by the toxicity of 5-FU at 24 hours and 48 hours, RER were observed to keep the typical lamella structure of cisternae from 24 to 72 hours group, but inner cavity kept on dilating. In SER, inner cavity were also observed to flatten from 24 to 72 hours group. Mitochnodria were always shown normal. All cell organelles were simillar to those of normal groups at 96 hours. Accordingly, it can be said that the treatment of 50 prevents the cytotoxicity of 5-FU on cell organelles of liver cell and that is concerned with the formation of membrane system of cell organelles.