1. Enhanced autophagic-lysosomal activity and increased BAG3-mediated selective macroautophagy as adaptive response of neuronal cells to chronic oxidative stress
- Author
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Elisabeth Sehn, Christian Behl, Christof Hiebel, Franz H. Grus, Vanessa Felzen, Uwe Wolfrum, Caroline Manicam, Natarajan Perumal, Debapriya Chakraborty, and Elisabeth Stürner
- Subjects
0301 basic medicine ,Clinical Biochemistry ,LFQ, Label-free quantification ,LETM, Leucine zipper and EF-hand containing transmembrane protein ,medicine.disease_cause ,Biochemistry ,CHX, Cycloheximide ,0302 clinical medicine ,BNIP3, Bcl-2 interacting protein 3 ,RAPA, Rapamycin ,PIK3C3, Class III PI3‐kinase ,Phosphorylation ,lcsh:QH301-705.5 ,Neurons ,lcsh:R5-920 ,PolyUB, Polyubiquitin ,Chemistry ,BAG3 ,OPA1, Optic atrophy 1 ,TOR Serine-Threonine Kinases ,WIPI1, WD repeat domain phosphoinositide-interacting protein 1 ,ATG, Autophagy related ,TFEB, Transcription factor EB ,Cell biology ,Mitochondria ,siRNA, Small interfering RNA ,DLP1, Dynamin-like protein 1 ,LAMP1, Lysosomal‐associated membrane protein 1 ,PURO, Puromycin ,lcsh:Medicine (General) ,Protein homeostasis ,Research Paper ,BafA1, Bafilomycin A1 ,LAMP2, Lysosomal‐associated membrane protein 2 ,Proteasome Endopeptidase Complex ,RAB18, Member RAS oncogene ,TUB, Tubulin ,LC3, Light chain 3 protein ,Oxidative phosphorylation ,CTSD, Cathepsin D ,Models, Biological ,Cell Line ,03 medical and health sciences ,Downregulation and upregulation ,Macroautophagy ,medicine ,Autophagy ,Humans ,Adaptation ,BAG1, Bcl-2-associated athanogene 1 ,BECN1, Beclin1 ,PI3K/AKT/mTOR pathway ,Adaptor Proteins, Signal Transducing ,TEM, Transmission electron microscopy ,Hsp70, Heat shock protein 70 ,Organic Chemistry ,Autophagosomes ,mTOR, Mammalian target of rapamycin ,Hsp70 ,Oxidative Stress ,030104 developmental biology ,Proteostasis ,lcsh:Biology (General) ,CV, Canavanine ,BAG3, Bcl-2-associated athanogene 3 ,MTT, (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) ,Apoptosis Regulatory Proteins ,Lysosomes ,030217 neurology & neurosurgery ,Oxidative stress - Abstract
Oxidative stress and a disturbed cellular protein homeostasis (proteostasis) belong to the most important hallmarks of aging and of neurodegenerative disorders. The proteasomal and autophagic-lysosomal degradation pathways are key measures to maintain proteostasis. Here, we report that hippocampal cells selected for full adaptation and resistance to oxidative stress induced by hydrogen peroxide (oxidative stress-resistant cells, OxSR cells) showed a massive increase in the expression of components of the cellular autophagic-lysosomal network and a significantly higher overall autophagic activity. A comparative expression analysis revealed that distinct key regulators of autophagy are upregulated in OxSR cells. The observed adaptive autophagic response was found to be independent of the upstream autophagy regulator mTOR but is accompanied by a significant upregulation of further downstream components of the canonical autophagy network such as Beclin1, WIPI1 and the transmembrane ATG9 proteins. Interestingly, the expression of the HSP70 co-chaperone BAG3, mediator of BAG3-mediated selective macroautophagy and highly relevant for the clearance of aggregated proteins in cells, was found to be increased in OxSR cells that were consequently able to effectively overcome proteotoxic stress. Overexpression of BAG3 in oxidative stress-sensitive HT22 wildtype cells partly established the vesicular phenotype and the enhanced autophagic flux seen in OxSR cells suggesting that BAG3 takes over an important part in the adaptation process. A full proteome analysis demonstrated additional changes in the expression of mitochondrial proteins, metabolic enzymes and different pathway regulators in OxSR cells as consequence of the adaptation to oxidative stress in addition to autophagy-related proteins. Taken together, this analysis revealed a wide variety of pathways and players that act as adaptive response to chronic redox stress in neuronal cells., Graphical abstract Image 1, Highlights • OxSR cells have significantly higher autophagic activity. • Several positive modulators of autophagy network are highly upregulated in OxSR cells e.g. BECN1, PI3KC3, WIPI1 and RAB18. • BAG3 is actively involved in maintenance of protein homeostasis and autophagic activity in OxSR cells.
- Published
- 2019