Lysosome dysfunction triggers Atg7-dependent neural apoptosis. 2010

Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0017, USA. kcwalls@uab.edu

Macroautophagy (autophagy) is a process wherein bulk cytosolic proteins and damaged organelles are sequestered and degraded via the lysosome. Alterations in autophagy-associated proteins have been shown to cause neural tube closure defects, neurodegeneration, and tumor formation. Normal lysosome function is critical for autophagy completion and when altered may lead to an accumulation of autophagic vacuoles (AVs) and caspase activation. The tumor suppressor p53 is highly expressed in neural precursor cells (NPCs) and has an important role in the regulation of both autophagy and apoptosis. We hypothesized that altered lysosome function would lead to NPC death via an interaction between autophagy- and apoptosis-associated proteins. To test our hypothesis, we utilized FGF2-expanded NPCs and the neural stem cell line, C17.2, in combination with the lysosomotropic agent chloroquine (CQ) and the vacuolar ATPase inhibitor bafilomycin A1 (Baf A1). Both CQ and Baf A1 caused concentration- and time-dependent AV accumulation, p53 phosphorylation, increased damage regulator autophagy modulator levels, caspase-3 activation, and cell death. Short hairpin RNA knockdown of Atg7, but not Beclin1, expression significantly inhibited CQ- and Baf A1-induced cell death, indicating that Atg7 is an upstream mediator of lysosome dysfunction-induced cell death. Cell death and/or caspase-3 activation was also attenuated by protein synthesis inhibition, p53 deficiency, or Bax deficiency, indicating involvement of the intrinsic apoptotic death pathway. In contrast to lysosome dysfunction, starvation-induced AV accumulation was inhibited by either Atg7 or Beclin1 knockdown, and Atg7 knockdown had no effect on starvation-induced death. These findings indicate that Atg7- and Beclin1-induced autophagy plays a cytoprotective role during starvation but that Atg7 has a unique pro-apoptotic function in response to lysosome dysfunction.

UI MeSH Term Description Entries
D008247 Lysosomes A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured or undergoes MEMBRANE FUSION. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed). Autolysosome,Autolysosomes,Lysosome
D008810 Mice, Inbred C57BL One of the first INBRED MOUSE STRAINS to be sequenced. This strain is commonly used as genetic background for transgenic mouse models. Refractory to many tumors, this strain is also preferred model for studying role of genetic variations in development of diseases. Mice, C57BL,Mouse, C57BL,Mouse, Inbred C57BL,C57BL Mice,C57BL Mice, Inbred,C57BL Mouse,C57BL Mouse, Inbred,Inbred C57BL Mice,Inbred C57BL Mouse
D008869 Microtubule-Associated Proteins High molecular weight proteins found in the MICROTUBULES of the cytoskeletal system. Under certain conditions they are required for TUBULIN assembly into the microtubules and stabilize the assembled microtubules. Ensconsin,Epithelial MAP, 115 kDa,Epithelial Microtubule-Associate Protein, 115 kDa,MAP4,Microtubule Associated Protein,Microtubule Associated Protein 4,Microtubule Associated Protein 7,Microtubule-Associated Protein,Microtubule-Associated Protein 7,E-MAP-115,MAP1 Microtubule-Associated Protein,MAP2 Microtubule-Associated Protein,MAP3 Microtubule-Associated Protein,Microtubule Associated Proteins,Microtubule-Associated Protein 1,Microtubule-Associated Protein 2,Microtubule-Associated Protein 3,7, Microtubule-Associated Protein,Associated Protein, Microtubule,E MAP 115,Epithelial Microtubule Associate Protein, 115 kDa,MAP1 Microtubule Associated Protein,MAP2 Microtubule Associated Protein,MAP3 Microtubule Associated Protein,Microtubule Associated Protein 1,Microtubule Associated Protein 2,Microtubule Associated Protein 3,Microtubule-Associated Protein, MAP1,Microtubule-Associated Protein, MAP2,Microtubule-Associated Protein, MAP3,Protein 7, Microtubule-Associated,Protein, Microtubule Associated,Protein, Microtubule-Associated
D009474 Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM. Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D002531 Cerebellum The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills. Cerebella,Corpus Cerebelli,Parencephalon,Cerebellums,Parencephalons
D002738 Chloroquine The prototypical antimalarial agent with a mechanism that is not well understood. It has also been used to treat rheumatoid arthritis, systemic lupus erythematosus, and in the systemic therapy of amebic liver abscesses. Aralen,Arechine,Arequin,Chingamin,Chlorochin,Chloroquine Sulfate,Chloroquine Sulphate,Khingamin,Nivaquine,Sulfate, Chloroquine,Sulphate, Chloroquine
D005455 Fluorescent Antibody Technique Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy. Antinuclear Antibody Test, Fluorescent,Coon's Technique,Fluorescent Antinuclear Antibody Test,Fluorescent Protein Tracing,Immunofluorescence Technique,Coon's Technic,Fluorescent Antibody Technic,Immunofluorescence,Immunofluorescence Technic,Antibody Technic, Fluorescent,Antibody Technics, Fluorescent,Antibody Technique, Fluorescent,Antibody Techniques, Fluorescent,Coon Technic,Coon Technique,Coons Technic,Coons Technique,Fluorescent Antibody Technics,Fluorescent Antibody Techniques,Fluorescent Protein Tracings,Immunofluorescence Technics,Immunofluorescence Techniques,Protein Tracing, Fluorescent,Protein Tracings, Fluorescent,Technic, Coon's,Technic, Fluorescent Antibody,Technic, Immunofluorescence,Technics, Fluorescent Antibody,Technics, Immunofluorescence,Technique, Coon's,Technique, Fluorescent Antibody,Technique, Immunofluorescence,Techniques, Fluorescent Antibody,Techniques, Immunofluorescence,Tracing, Fluorescent Protein,Tracings, Fluorescent Protein
D000071193 Autophagy-Related Protein 7 An autophagy related protein that is similar to UBIQUITIN-ACTIVATING ENZYME E1. It functions in CYTOPLASM to VACUOLE transport (Cvt) and AUTOPHAGY by activating ATG12 PROTEIN for its conjugation with ATG5 PROTEIN, as well as the conjugation of ATG8 FAMILY PROTEINS with phosphatidylethanolamine for ATG8 association to Cvt vesicles and AUTOPHAGOSOME membranes. It is also required for the nitrogen starvation response in yeast, MITOPHAGY; and autophagic cell death induced by CASPASE 8 inhibition. ATG12-Activating Enzyme E1 ATG7,ATG7 Protein,Ubiquitin-Activating Enzyme E1-like Protein,Ubiquitin-Like Modifier-Activating Enzyme ATG7,ATG12 Activating Enzyme E1 ATG7,Autophagy Related Protein 7,Ubiquitin Activating Enzyme E1 like Protein,Ubiquitin Like Modifier Activating Enzyme ATG7
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D000935 Antifungal Agents Substances that destroy fungi by suppressing their ability to grow or reproduce. They differ from FUNGICIDES, INDUSTRIAL because they defend against fungi present in human or animal tissues. Anti-Fungal Agents,Antifungal Agent,Fungicides, Therapeutic,Antibiotics, Antifungal,Therapeutic Fungicides,Agent, Antifungal,Anti Fungal Agents,Antifungal Antibiotics

Related Publications

Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
January 2012, Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
September 2021, Autophagy,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
July 2001, Molecular biology of the cell,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
April 2019, Journal of lipid research,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
January 2011, Chemical & pharmaceutical bulletin,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
September 2022, Phytomedicine : international journal of phytotherapy and phytopharmacology,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
February 2020, International journal of molecular sciences,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
August 2020, Haematologica,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
June 2014, Toxicology in vitro : an international journal published in association with BIBRA,
Ken C Walls, and Arindam P Ghosh, and Aimee V Franklin, and Barbara J Klocke, and Mary Ballestas, and John J Shacka, and Jianhua Zhang, and Kevin A Roth
March 2013, The international journal of biochemistry & cell biology,
Copied contents to your clipboard!