No abstract available.
Animals ; Hepatocytes* ; Organelles* ; Rats*

Autophagy is an important homeostatic cellular recycling mechanism responsible for degrading injured or dysfunctional subcellular organelles and proteins in all living cells. The process of autophagy can be divided into three relatively independent steps: the initiation of phagophore, the formation of autophagosome and the maturation/degradation stage. Different morphological characteristics and molecular marker changes can be observed at these stages. Morphological approaches are useful to produce novel knowledge that would not be achieved through other experimental methods. Here we summarize the morphological methods in monitoring autophagy, the principles in data interpretation and the cautions that should be considered in the study of autophagy.
Autophagy ; Homeostasis ; Humans ; Organelles ; Phagosomes

Autophagy is a self-degradative process that removes misfolded or aggregated proteins, clears damaged organelles, as well as eliminates intracellular pathogens playing a role in innate immunity. Mycobacterium abscessus (M. abscessus) has been reported as a causative organism in nearly 80% of the rapid growing mycobacteria (RGM) pulmonary disease. The strain exhibits two different colony types: the smooth (S) one which is considered wild-type and the rough (R) one which is the mutated strain. In accordance to the colony morphology, the S and R types display varying autophagic responses in the host cells with the R type inducing elevated autophagy compared to the S type. The major difference in the autophagy could be based on the bioactive molecules exposed on the surface of the S and R types. Though autophagy has a vital role to play in the clearance of intracellular pathogens, very little is known on the autophagy induced by M. abscessus. It has been known that the intracellular pathogens employ different strategies to evade the autophagic pathway and to survive within the host cells. This review summarizes the most up-to-date findings on autophagy induced by M. abscessus morphotypes and how M. abscessus evades the autophagic machinery to divide and thrive inside the host cells. In addition, the prospects of autophagic machinery in devising new anti-infective strategies against mycobacterial infection is also been discussed.
Autophagy* ; Immunity, Innate ; Lung Diseases ; Mycobacterium* ; Organelles

Autophagy is a self-degradative process that removes misfolded or aggregated proteins, clears damaged organelles, as well as eliminates intracellular pathogens playing a role in innate immunity. Mycobacterium abscessus (M. abscessus) has been reported as a causative organism in nearly 80% of the rapid growing mycobacteria (RGM) pulmonary disease. The strain exhibits two different colony types: the smooth (S) one which is considered wild-type and the rough (R) one which is the mutated strain. In accordance to the colony morphology, the S and R types display varying autophagic responses in the host cells with the R type inducing elevated autophagy compared to the S type. The major difference in the autophagy could be based on the bioactive molecules exposed on the surface of the S and R types. Though autophagy has a vital role to play in the clearance of intracellular pathogens, very little is known on the autophagy induced by M. abscessus. It has been known that the intracellular pathogens employ different strategies to evade the autophagic pathway and to survive within the host cells. This review summarizes the most up-to-date findings on autophagy induced by M. abscessus morphotypes and how M. abscessus evades the autophagic machinery to divide and thrive inside the host cells. In addition, the prospects of autophagic machinery in devising new anti-infective strategies against mycobacterial infection is also been discussed.
Autophagy* ; Immunity, Innate ; Lung Diseases ; Mycobacterium* ; Organelles

The eukaryotic cell is compartmentalized by a series of vesicular organelles which constitute the endocytic and exocytic transport pathways. Each vesicular compartment has distinct sets of membrane proteins, structures and functions. Despite continuous vesicular transport, each vesicular compartment maintains its structure and function by use of retention and retrieval signal for its own resident proteins. Proteins in transit along the endocytic and exocytic pathway are transported without admixing with cytoplasmic constituents by successive steps of budding from the donor vesicles, formation of intermediate transport vesicles, transport, targeting to and fusion with acceptor vesicles. Specificity and fidelity of the vesicular transport are conferred by vesicular membrane proteins and small molecular weight GTP-binding proteins of the Rab subfamily. Proteins for export are packaged into specific vesicles for their final destinations. Insertion into and retrieval from the plasma membrane of transport proteins in response to cellular stimulus are a new paradigm of cellular regulatory mechanism. Secretion of neurotransmitters, hormones and enzymes by exocytosis involves a complex set of cytosolic proteins, G-proteins, proteins on the secretory granule membrane and plasma membrane. Much progress has been recently made in identifying proteins and factors involved in the exocytosis. But the molecular interactions among identified proteins and regulatory factors are unknown and remain to be elucidated. Finally our chemiosmotic hypothesis which involves the H+ electrochemical gradient across the secretory granule membrane generated by an ATP-dependent electrogenic H(+)-ATPase as the potential driving force for fusion and release of granule contents will be discussed.
Biological Transport ; *Exocytosis ; Human ; Organelles/*metabolism ; Support, Non-U.S. Gov't

Myeloid body formation is an ultrastructural feature of gentamicin induced nephrotoxicity in human being and experimental animals. The origin of the myeloid body is not satisfactorily understood and morphological verification of the developing process of this structure is not fully accomplished. We injected 100 mg/kg/12 hour of gentamicin in 20 Spraque-Dawley rats and examined the ultrastructural feature of the proximal convoluted tubular cells of the kidney every 30 minutes in the first 4 hours, and in 5 hours, 6 hours, 12 hours, 24 hours and 48 hours after injection of gentamicin, with a TEM and a SEM. Myeloid bodies were noted as concentric layers of membranous structures of degenerated endoplasmic reticulum and mitochondria in the lysosome. The number and size of the myeloid body containing lysosomes were increased with time. We can deduce from this observation that injured cell organelles by diffusible gentamicin within the cells are autophagocytosed by lysosomes which were also injured by the drug from pinocytotic vesicles, and incompletely digested organellar remnants are retained in the lysosomes as myeloid bodies. So we think that the myeloid body formation is a result of an exaggerated and a pathologic autophagocytic process due to cell injury induced by gentamicin.
Animals ; Endoplasmic Reticulum ; Gentamicins* ; Humans ; Kidney ; Lysosomes ; Mitochondria ; Organelles ; Rats*

Modern drug delivery system demands high therapeutic efficacy and low toxicity which depends on efficient intracellular transportation of therapeutics to specific organisms, cells, even targeted organelles such as cytosol, nucleus, mitochondria, lysosome and endoplasmic reticulum. Intracellular barriers which prevent drug molecules accessing to their targets mainly include cell membrane, lysosomal degradation and the endomembrane system. Nanocarriers can preserve the bioactivities of protein, enzyme and DNA, and also they are easy to be modified and functionalized. In this paper, we summarized the intracellular fate of nanocarriers, especially how to bypass intracellular barriers and then target cytosol, nucleus, mitochondria, lysosome and endoplasmic reticulum by pharmaceutical modifications.
Animals ; Drug Carriers ; Drug Delivery Systems ; Humans ; Nanoparticles ; Organelles

OBJECTIVES: There have been developed to use targeting ability for antimicrobial, anticancerous, gene therapy and cosmetics through analysis of various membrane proteins isolated from cell organelles. METHODS: It was examined about the lysosomal membrane protein extracted from lysosome isolated from HeLa cell treated by 100 ppm melanin for 24 hours in order to find associated with targeting ability to melanin using by 2-dimensional electrophoresis. RESULTS: The result showed 14 up-regulated (1.5-fold) and 13 down-regulated (2.0-fold) spots in relation to melanin exposure. CONCLUSIONS: It has been found that lysosomal membrane proteins are associated with melanin to decolorize and quantity through cellular activation of lysosome.
Electrophoresis ; Genetic Therapy ; HeLa Cells* ; Humans ; Lysosome-Associated Membrane Glycoproteins* ; Lysosomes ; Melanins* ; Membrane Proteins ; Organelles

BACKGROUND: Dermatophytes are common pathogens of cutaneous fungal infections. Although antifungal agents have been used widely on the dermatophyte infections, the ultrastructural changes of dermatophytes caused by drugs have not been described in detail elsewhere. OBJECTIVE: We compared the ultrastructures of common dermatophytes and their changes after exposure to three antifungal agents, itraconazole, terbinafine and creosote, to inform the effectiveness of drugs on ultrastructures of dermatophytes. METHODS: Two strains of Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis were cultivated on Sabouraud dextrose agar(SDA). Conventional electron microscopic specimen preparation was performed and examined by transmission electron microscope. After 24-hour exposure of each strain with 100 microgram/ml of itraconazole, 50 microgram/ml of terbinafine and 100 microgram/ml of creosote on SDA, the ultrastructural changes of their hyphae were investigated. RESULTS: The ultrastructural findings of each dermatophyte were similar. Tube-like hyphae and simple septal pores with Woronin bodies were typical findings. There were one or more than one nuclei and various intracellular organelles between the septa. A greater density of cytoplasm and organelles could be seen in the younger hyphae. Microscopically, destruction of the cell wall, edema and necrosis of intracellular organelles, and an increase in the number and size of vacuoles could be seen after drug exposure. After exposure to itraconazole and terbinafine, edema and necrosis of the cell wall and membranous structures were found, as well as, membranous bodies that represented destructive changes in the cell wall. The hyphae exposed to terbinafine showed various sized of lipid globule in the cytoplasm. Creosote exposure lead to a more non-specific and severer necrotic pattern of the intracellular structures. CONCLUSION: There seemed to be similar features of normal hyphae of dermatophytes. Antifungal agents, itraconazole and terbinafine, affected membranous structures of dermatophytes, whereas creosote acted on internal structures by a nonspecific direct toxic effect. Transmission electron microscope was a useful tool to investigate the changes of internal ultrastructure of dermatophyte by antifungal agents.
Antifungal Agents* ; Arthrodermataceae* ; Cell Wall ; Creosote ; Cytoplasm ; Edema ; Glucose ; Hyphae ; Itraconazole ; Microsporum ; Necrosis ; Organelles ; Trichophyton ; Vacuoles

Histochemical and electron microscopic studies were made on the canal epithelium of the body segment of the rabbit epididymis and following results were obtained. 1) Acid phosphatase activity was marked in the canal epithelium. especially of the proximal body segment of the epididymis. Granules reactive to the acid phosphatase were present in both the above and below the nucleus 2) Electron microscopic finding: Canal epithelium of the body segment of the rabbit epididymis consisted of largely principal cells. Very few light and few basal cells. Principal cells were characterized by having slender microvilli (stereocilia). Luminal vesicles and vacuoles, extensive Golgi areas and many dense bodies in the supranuclear region, remarkable endoplasmic reticulum of mainly agranular type throughout the cytoplasm. Infranuclear cytoplasm contained often abundant mitochodria, many dense bodies and significant amount of granular endoplasmic reticulum. Light cells were characterized by having light cytoplasm, numerous vesicles, many vacuoles and dense bodies. Basal cells were present characterized by haying small nucleus, small number of cell organelles and rather clear cytoplasm From these results, it is suggested that the principal cell may have dual function of secretion and absorption and the light cell may engage mainly in absorptive function.
Absorption ; Acid Phosphatase ; Cytoplasm ; Endoplasmic Reticulum ; Endoplasmic Reticulum, Rough ; Epididymis* ; Epithelium* ; Male ; Microvilli ; Organelles ; Phenobarbital ; Vacuoles