scholarly journals Corrigendum to: Loss of supervillin causes myopathy with myofibrillar disorganization and autophagic vacuoles

Brain ◽  
2020 ◽  
Keyword(s):  
Autophagic Vacuoles

Further Ultrastructural Observations on Metastatic Nodules of Human Breast Cancer

1968 ◽  
Vol 26 ◽  
pp. 224-225
Author(s):  
John L. Swedo ◽  
R. W. Talley ◽  
John H. L. Watson
Keyword(s):  
Breast Cancer ◽  
Human Breast Cancer ◽  
Estrogen Therapy ◽  
Specimen Preparation ◽  
Human Breast ◽  
Autophagic Vacuoles ◽  
Previous Communication ◽  
Linear Profiles ◽  
Metastatic Nodule

Since the report, which described the ultrastructure of a metastatic nodule of human breast cancer after estrogen therapy, additional ultrastructural observations, including some which are correlative with pertinent findings in the literature concerning mycoplasmas, have been recorded concerning the same subject. Specimen preparation was identical to that in.The mitochondria possessed few cristae, and were deteriorated and vacuolated. They often contained particulates and fibrous structures, sometimes arranged in spindle-shaped bundles, Fig. 1. Another apparent aberration was the occurrence, Fig. 2 (arrows) of linear profiles of what seems to be SER, which lie between layers of RER, and are often recognizably continuous with them.It was noted that the structure of the round bodies, interpreted as within autophagic vacuoles in the previous communication, and of vesicular bodies, described morphologically closely resembled those of some mycoplasmas. Specifically, they simulated or reflected the various stages of replication reported for mycoplasmas grown on solid nutrient. Based on this observation, they are referred to here as “mycoplasma-like” structures, in anticipation of confirmatory evidence from investigations now in progress.

Prefertilization ovule development in Capsella: the dyad, tetrad, developing megaspore, and two-nucleate gametophyte

1986 ◽  
Vol 64 (4) ◽  
pp. 875-884 ◽  
Author(s):  
Patricia Schulz ◽  
William A. Jensen
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Acid Phosphatase ◽  
De Novo ◽  
Periodic Acid ◽  
Aniline Blue ◽  
Ovule Development ◽  
Periodic Acid Schiff ◽  
Fluorescent Material ◽  
Autophagic Vacuoles

Ovules of Capsella bursa-pastoris at the dyad and tetrad stages of meiosis and at the megaspore and two-nucleate stages of the gametophyte were studied with the electron microscope. The cells of the dyad and tetrad are separated by aniline blue fluorescent cross walls and receive all types of organelles and autophagic vacuoles that were present in the meiocyte. Autophagic vacuoles enclose ribosomes and organelles and show reaction product for acid phosphatase. Autophagic vacuoles and some plastids are absorbed into the enlarging vacuoles of the growing megaspore. Other plastids appear to survive meiosis and there is no evidence for their de novo origin. Some mitochondria appear to degenerate in the enlarging megaspore but others look healthy and there is no evidence for the de novo origin of mitochondria. The nucleolus of the developing megaspore becomes very large and the cytoplasm is extremely dense with ribosomes. The cell wall is thickened by an electron-translucent, periodic acid – Schiff negative, aniline blue fluorescent material and contains plasmodesmata that link the megaspore with the nucellus. The plasmalemma of the growing megaspore produces microvilluslike extensions into this wall that disappear with the formation of the two-nucleate gametophyte. Plasmodesmata disappear from the cell wall at the four-nucleate stage.

scholarly journals Isolation of autophagic vacuoles from rat liver: morphological and biochemical characterization.

1982 ◽  
Vol 93 (1) ◽  
pp. 144-154 ◽  
Author(s):  
L Marzella ◽  
J Ahlberg ◽  
H Glaumann
Keyword(s):  
Proteolytic Activity ◽  
Rat Liver ◽  
Biochemical Characterization ◽  
Secretory Granules ◽  
Density Lipoprotein ◽  
Marker Enzymes ◽  
Cell Organelles ◽  
Protein Ratio ◽  
Autophagic Vacuoles

The induction of autophagy caused by vinblastine (VBL) has been found to be concomitant with a stimulation of proteolysis in a mitochondrial-lysosomal (ML) fraction from the rat liver (Marzella and Glaumann, 1980, Lab. Invest., 42: 8-17. Marzella and Glaumann, 1980, Lab. Invest., 42:18-27). In this fraction the enhanced proteolysis is associated with a threefold increase in the relative fractional volume of autophagic vacuoles (AVs). In an attempt to isolate the AVs, we subfractionated the ML suspension at different intervals after the induction of autophagy by VBL by centrifugation on a discontinuous Metrizamide gradient ranging from 50% to 15%. The material banding at the 24 to 20% and the 20 to 15% interphases was collected. Morphological analysis reveals that 3 h after induction of autophagy these fractions consist predominantly (approximately 90%) of intact autophagic vacuoles. These autophagic vacuoles contain cytosol, mitochondria, portions of endoplasmic reticulum, and occasional very low density lipoprotein, particles either free or in Golgi apparatus derivatives, in particular secretory granules. The sequestered materials show ultrastructural signs of ongoing degradation. In addition to containing typical autophagic vacuoles, the isolated fractions consist of lysosomes lacking morphologically recognizable cellular components. Contamination from nonlysosomal material is only a few percent as judged from morphometric analysis. Typical lysosomal "marker" enzymes are enriched 15-fold, whereas the proteolytic activity is enriched 10- to 20-fold in the isolated AV fraction as compared to the homogenate. Initially, the yield of nonlysosomal mitochondrial and microsomal enzyme activities increases in parallel with the induction of autophagy but, later on, decreases with advanced degradation of the sequestered cell organelles. Therefore, in the case of AVs the presence of nonlysosomal marker enzymes cannot be used for calculation of fraction purity, since newly sequestered organelles are enzymatically active. Isolated autophagic vacuoles show proteolytic activity when incubated in vitro. The comparatively high phospholipid/protein ratio (0.5) of the AV fraction suggests that phospholipids are degraded more slow than proteins. Is it concluded that AVs can be isolated into a pure fraction and are the subcellular site of enhanced protein degradation in the rat liver after induction of autophagy.

scholarly journals AUTOPHAGIC VACUOLES PRODUCED IN VITRO

1968 ◽  
Vol 38 (2) ◽  
pp. 377-391 ◽  
Author(s):  
Martha E. Fedorko ◽  
James G. Hirsch ◽  
Zanvil A. Cohn
Keyword(s):  
Culture Medium ◽  
Amorphous Material ◽  
Vacuolar Membrane ◽  
Perinuclear Region ◽  
Linear Element ◽  
Autophagic Vacuoles ◽  
Dense Bodies ◽  
Mouse Macrophages ◽  
Cytoplasmic Structures

Mouse macrophages exposed to 30 µg/ml of chloroquine in vitro develop autophagic vacuoles containing various cytoplasmic components and acid phosphatase. The early toxic vacuoles appear in the perinuclear region within 15 min; on electron microscopy, they show irregular shape, amorphous moderately dense content, apparent double membranes, and in some instances curved thin tubular extensions with a central, dark linear element. Cytoplasmic structures are probably transported into the vacuoles by invagination of the vacuolar membrane. After exposure to chloroquine for 1–4 hr, macrophages display large vacuoles containing degraded cytoplasmic structures, membranous whorls, and amorphous material. When chloroquine is removed by changing the culture medium after 4 hr, the cells survive and 24 hr later they exhibit no abnormality except for large cytoplasmic dense bodies packed with membrane lamellae. During recovery chloroquine disappears from the cells. 24 hr after exposure to chloroquine the macrophages have accumulated less hydrolases than control cells.

Bcl-2, Bcl-x, and Bax Expression by Immunohistochemistry in Inclusion Body Myositis

2001 ◽  
Vol 125 (10) ◽  
pp. 1326-1330
Author(s):  
Richard A. Prayson ◽  
Albert C. Yu
Keyword(s):  
Inclusion Body ◽  
Inclusion Body Myositis ◽  
Staining Pattern ◽  
Apoptotic Cell ◽  
Muscle Fibers ◽  
Inflammatory Cells ◽  
Rimmed Vacuoles ◽  
Autophagic Vacuoles ◽  
Ultrastructural Evidence ◽  
Mitochondrial Defects

Abstract Context.—Bcl-2, Bcl-x, and Bax are among the variety of proteins that have been described as being involved in the regulation of apoptotic cell death. Bcl-2 and Bcl-xL inhibit apoptosis, and Bax is proapoptotic. Objective.—To evaluate the expression of Bcl-2, Bcl-x, and Bax in inclusion body myositis (IBM). Design.—We examined muscle specimens from 27 patients (17 men, 10 women) with IBM to evaluate Bcl-2, Bcl-x, and Bax expression by immunohistochemistry. Results.—Patient ages ranged from 29 to 80 years (mean 62.2 years). All biopsies were marked by endomysial chronic inflammation, muscle fiber necrosis, and regeneration. Rimmed (autophagic) vacuoles were present in all cases. Ragged red fibers were noted in 4 biopsies (15%), and cytochrome oxidase–deficient fibers were found in 10 biopsies (37%). Ultrastructural evidence of intranuclear or cytoplasmic tubulofilamentous inclusions, confirming the diagnosis of IBM, were noted in all cases. Paracrystalline mitochondrial inclusions were seen in 5 biopsies (18.5%). Inflammatory cells stained positively with Bcl-2 in all biopsies, Bax in 26 biopsies (96%), and Bcl-x in 8 biopsies (30%). Degenerating muscle fibers were highlighted with Bax in 24 biopsies (89%), Bcl-2 in 2 biopsies (7%), and Bcl-x in 3 biopsies (11%). Regenerative muscle fibers were noted to stain with Bax in 24 muscles (89%), Bcl-2 in 21 muscles (78%), and Bcl-x in 4 muscles (15%). Rimmed vacuoles were highlighted by Bax in 24 biopsies (89%) and only rarely by Bcl-2 (n = 2, 7%) and Bcl-x (n = 3, 11%). A subsarcolemmal staining pattern was observed in 21 biopsies (78%) with Bax, 6 biopsies (22%) with Bcl-2, and only 1 biopsy (4%) with Bcl-x. Conclusions.—(1) Bax (proapoptotic) immunostaining highlighted most autophagic vacuoles; (2) subsarcolemmal Bax and Bcl-2 immunoreactivity may be associated with mitochondrial defects that are commonly noted in IBM; (3) Bcl-2 and Bax immunoreactivity were not confined to degenerating muscle fibers and in fact appeared to be expressed more commonly in regenerating fibers, suggesting that their expression may be independent of apoptosis in the setting of IBM.

Lysosomal Storage Disorders

2021 ◽  
pp. 1106-1113
Author(s):  
Radhika Dhamija ◽  
Erin Conboy ◽  
Lily C. Wong-Kisiel
Keyword(s):  
Lysosomal Storage Diseases ◽  
Lysosomal Storage Disorders ◽  
Lysosomal Storage ◽  
Storage Diseases ◽  
Activator Proteins ◽  
Autophagic Vacuoles ◽  
Enzyme Substrate ◽  
Membrane Bound ◽  
Considerable Morbidity ◽  
Storage Disorders

Lysosomes are membrane-bound organelles that degrade various macromolecules. Lysosomal storage diseases are a clinically, enzymatically, and genetically heterogeneous group of disorders resulting from intracellular accumulation of substrates. Mechanisms of lysosomal storage disorders include 1) primary deficiency of specific hydrolases; 2) defects in activator proteins required for enzyme-substrate interactions in posttranslational modification of enzymes or in transport of the substrate from lysosomes; and 3) abnormalities of fusion between autophagic vacuoles and lysosomes. Substrate accumulation is slowly progressive, leading to considerable morbidity and mortality.

Cell survival under nutrient stress is dependent on metabolic conditions regulated by Akt and not by autophagic vacuoles

2007 ◽  
Vol 19 (10) ◽  
pp. 2118-2126 ◽  
Author(s):  
P. Bruno ◽  
A. Calastretti ◽  
M. Priulla ◽  
L. Asnaghi ◽  
F. Scarlatti ◽  
...  
Keyword(s):  
Cell Survival ◽  
Nutrient Stress ◽  
Autophagic Vacuoles ◽  
Metabolic Conditions

Autophagic vacuoles in experimental atrophy

1971 ◽  
Vol 14 (2) ◽  
pp. 158-175 ◽  
Author(s):  
Solon Cole ◽  
Alex Matter ◽  
Morris J. Karnovsky
Keyword(s):  
Autophagic Vacuoles
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