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Autophagy is Activated In Vivo during Trimethyltin-Induced Apoptotic Neurodegeneration: A Study in the Rat Hippocampus

Trimethyltin (TMT) is an organotin compound known to produce significant and selective neuronal degeneration and reactive astrogliosis in the rodent central nervous system. Autophagy is the main cellular mechanism for degrading and recycling protein aggregates and damaged organelles, which in differ...

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Autores principales: Ceccariglia, Sabrina, Alvino, Alessandra, Del Fà, Aurora, Parolini, Ornella, Michetti, Fabrizio, Gangitano, Carlo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6982133/
https://www.ncbi.nlm.nih.gov/pubmed/31881802
http://dx.doi.org/10.3390/ijms21010175
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author Ceccariglia, Sabrina
Alvino, Alessandra
Del Fà, Aurora
Parolini, Ornella
Michetti, Fabrizio
Gangitano, Carlo
author_facet Ceccariglia, Sabrina
Alvino, Alessandra
Del Fà, Aurora
Parolini, Ornella
Michetti, Fabrizio
Gangitano, Carlo
author_sort Ceccariglia, Sabrina
collection PubMed
description Trimethyltin (TMT) is an organotin compound known to produce significant and selective neuronal degeneration and reactive astrogliosis in the rodent central nervous system. Autophagy is the main cellular mechanism for degrading and recycling protein aggregates and damaged organelles, which in different stress conditions, such as starvation, generally improves cell survival. Autophagy is documented in several pathologic conditions, including neurodegenerative diseases. This study aimed to investigate the autophagy and apoptosis signaling pathways in hippocampal neurons of TMT-treated (Wistar) rats to explore molecular mechanisms involved in toxicant-induced neuronal injury. The microtubule-associated protein light chain (LC3, autophagosome marker) and sequestosome1 (SQSTM1/p62) (substrate of autophagy-mediated degradation) expressions were examined by Western blotting at different time points after intoxication. The results demonstrate that the LC3 II/I ratio significantly increased at 3 and 5 days, and that p62 levels significantly decreased at 7 and 14 days. Immunofluorescence images of LC3/neuronal nuclear antigen (NeuN) showed numerous strongly positive LC3 neurons throughout the hippocampus at 3 and 5 days. The terminal deoxynucleotidyltransferase dUTP nick end labeling (TUNEL) assay indicated an increase in apoptotic cells starting from 5 days after treatment. In order to clarify apoptotic pathway, immunofluorescence images of apoptosis-inducing factor (AIF)/NeuN did not show nuclear translocation of AIF in neurons. Increased expression of cleaved Caspase-3 was revealed at 5–14 days in all hippocampal regions by Western blotting and immunohistochemistry analyses. These data clearly demonstrate that TMT intoxication induces a marked increase in both autophagy and caspase-dependent apoptosis, and that autophagy occurring just before apoptosis could have a potential role in neuronal loss in this experimental model of neurodegeneration.
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spelling pubmed-69821332020-02-07 Autophagy is Activated In Vivo during Trimethyltin-Induced Apoptotic Neurodegeneration: A Study in the Rat Hippocampus Ceccariglia, Sabrina Alvino, Alessandra Del Fà, Aurora Parolini, Ornella Michetti, Fabrizio Gangitano, Carlo Int J Mol Sci Article Trimethyltin (TMT) is an organotin compound known to produce significant and selective neuronal degeneration and reactive astrogliosis in the rodent central nervous system. Autophagy is the main cellular mechanism for degrading and recycling protein aggregates and damaged organelles, which in different stress conditions, such as starvation, generally improves cell survival. Autophagy is documented in several pathologic conditions, including neurodegenerative diseases. This study aimed to investigate the autophagy and apoptosis signaling pathways in hippocampal neurons of TMT-treated (Wistar) rats to explore molecular mechanisms involved in toxicant-induced neuronal injury. The microtubule-associated protein light chain (LC3, autophagosome marker) and sequestosome1 (SQSTM1/p62) (substrate of autophagy-mediated degradation) expressions were examined by Western blotting at different time points after intoxication. The results demonstrate that the LC3 II/I ratio significantly increased at 3 and 5 days, and that p62 levels significantly decreased at 7 and 14 days. Immunofluorescence images of LC3/neuronal nuclear antigen (NeuN) showed numerous strongly positive LC3 neurons throughout the hippocampus at 3 and 5 days. The terminal deoxynucleotidyltransferase dUTP nick end labeling (TUNEL) assay indicated an increase in apoptotic cells starting from 5 days after treatment. In order to clarify apoptotic pathway, immunofluorescence images of apoptosis-inducing factor (AIF)/NeuN did not show nuclear translocation of AIF in neurons. Increased expression of cleaved Caspase-3 was revealed at 5–14 days in all hippocampal regions by Western blotting and immunohistochemistry analyses. These data clearly demonstrate that TMT intoxication induces a marked increase in both autophagy and caspase-dependent apoptosis, and that autophagy occurring just before apoptosis could have a potential role in neuronal loss in this experimental model of neurodegeneration. MDPI 2019-12-25 /pmc/articles/PMC6982133/ /pubmed/31881802 http://dx.doi.org/10.3390/ijms21010175 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Ceccariglia, Sabrina
Alvino, Alessandra
Del Fà, Aurora
Parolini, Ornella
Michetti, Fabrizio
Gangitano, Carlo
Autophagy is Activated In Vivo during Trimethyltin-Induced Apoptotic Neurodegeneration: A Study in the Rat Hippocampus
title Autophagy is Activated In Vivo during Trimethyltin-Induced Apoptotic Neurodegeneration: A Study in the Rat Hippocampus
title_full Autophagy is Activated In Vivo during Trimethyltin-Induced Apoptotic Neurodegeneration: A Study in the Rat Hippocampus
title_fullStr Autophagy is Activated In Vivo during Trimethyltin-Induced Apoptotic Neurodegeneration: A Study in the Rat Hippocampus
title_full_unstemmed Autophagy is Activated In Vivo during Trimethyltin-Induced Apoptotic Neurodegeneration: A Study in the Rat Hippocampus
title_short Autophagy is Activated In Vivo during Trimethyltin-Induced Apoptotic Neurodegeneration: A Study in the Rat Hippocampus
title_sort autophagy is activated in vivo during trimethyltin-induced apoptotic neurodegeneration: a study in the rat hippocampus
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6982133/
https://www.ncbi.nlm.nih.gov/pubmed/31881802
http://dx.doi.org/10.3390/ijms21010175
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