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Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death

Hepatocytes on exposure to high levels of lipids reorganize the metabolic program while fighting against the toxicity associated with elevated cellular lipids. The mechanism of this metabolic reorientation and stress management in lipid-challenged hepatocytes has not been well explored. We have note...

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Autores principales: Bandyopadhyay, Diptankar, Basu, Sudarshana, Mukherjee, Ishita, Chakrabarti, Saikat, Chakrabarti, Partha, Mukherjee, Kamalika, Bhattacharyya, Suvendra N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Biochemistry and Molecular Biology 2023
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Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10413358/
https://www.ncbi.nlm.nih.gov/pubmed/37394005
http://dx.doi.org/10.1016/j.jbc.2023.104999
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author Bandyopadhyay, Diptankar
Basu, Sudarshana
Mukherjee, Ishita
Chakrabarti, Saikat
Chakrabarti, Partha
Mukherjee, Kamalika
Bhattacharyya, Suvendra N.
author_facet Bandyopadhyay, Diptankar
Basu, Sudarshana
Mukherjee, Ishita
Chakrabarti, Saikat
Chakrabarti, Partha
Mukherjee, Kamalika
Bhattacharyya, Suvendra N.
author_sort Bandyopadhyay, Diptankar
collection PubMed
description Hepatocytes on exposure to high levels of lipids reorganize the metabolic program while fighting against the toxicity associated with elevated cellular lipids. The mechanism of this metabolic reorientation and stress management in lipid-challenged hepatocytes has not been well explored. We have noted the lowering of miR-122, a liver-specific miRNA, in the liver of mice fed with either a high-fat diet or a methionine–choline-deficient diet that is associated with increased fat accumulation in mice liver. Interestingly, low miR-122 levels are attributed to the enhanced extracellular export of miRNA processor enzyme Dicer1 from hepatocytes in the presence of high lipids. Export of Dicer1 can also account for the increased cellular levels of pre-miR-122—the substrate of Dicer1. Interestingly, restoration of Dicer1 levels in the mouse liver resulted in a strong inflammatory response and cell death in the presence of high lipids. Increasing death of hepatocytes was found to be caused by increased miR-122 levels in hepatocytes restored for Dicer1. Thus, the Dicer1 export by hepatocytes seems to be a key mechanism to combat lipotoxic stress by shunting out miR-122 from stressed hepatocytes. Finally, as part of this stress management, we determined that the Ago2-interacting pool of Dicer1, responsible for mature microribonucleoprotein formation in mammalian cells, gets depleted. miRNA-binder and exporter protein HuR is found to accelerate Ago2–Dicer1 uncoupling to ensure export of Dicer1 via extracellular vesicles in lipid-loaded hepatocytes.
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spelling pubmed-104133582023-08-11 Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death Bandyopadhyay, Diptankar Basu, Sudarshana Mukherjee, Ishita Chakrabarti, Saikat Chakrabarti, Partha Mukherjee, Kamalika Bhattacharyya, Suvendra N. J Biol Chem Research Article Hepatocytes on exposure to high levels of lipids reorganize the metabolic program while fighting against the toxicity associated with elevated cellular lipids. The mechanism of this metabolic reorientation and stress management in lipid-challenged hepatocytes has not been well explored. We have noted the lowering of miR-122, a liver-specific miRNA, in the liver of mice fed with either a high-fat diet or a methionine–choline-deficient diet that is associated with increased fat accumulation in mice liver. Interestingly, low miR-122 levels are attributed to the enhanced extracellular export of miRNA processor enzyme Dicer1 from hepatocytes in the presence of high lipids. Export of Dicer1 can also account for the increased cellular levels of pre-miR-122—the substrate of Dicer1. Interestingly, restoration of Dicer1 levels in the mouse liver resulted in a strong inflammatory response and cell death in the presence of high lipids. Increasing death of hepatocytes was found to be caused by increased miR-122 levels in hepatocytes restored for Dicer1. Thus, the Dicer1 export by hepatocytes seems to be a key mechanism to combat lipotoxic stress by shunting out miR-122 from stressed hepatocytes. Finally, as part of this stress management, we determined that the Ago2-interacting pool of Dicer1, responsible for mature microribonucleoprotein formation in mammalian cells, gets depleted. miRNA-binder and exporter protein HuR is found to accelerate Ago2–Dicer1 uncoupling to ensure export of Dicer1 via extracellular vesicles in lipid-loaded hepatocytes. American Society for Biochemistry and Molecular Biology 2023-06-30 /pmc/articles/PMC10413358/ /pubmed/37394005 http://dx.doi.org/10.1016/j.jbc.2023.104999 Text en © 2023 The Authors https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Research Article
Bandyopadhyay, Diptankar
Basu, Sudarshana
Mukherjee, Ishita
Chakrabarti, Saikat
Chakrabarti, Partha
Mukherjee, Kamalika
Bhattacharyya, Suvendra N.
Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death
title Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death
title_full Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death
title_fullStr Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death
title_full_unstemmed Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death
title_short Accelerated export of Dicer1 from lipid-challenged hepatocytes buffers cellular miRNA-122 levels and prevents cell death
title_sort accelerated export of dicer1 from lipid-challenged hepatocytes buffers cellular mirna-122 levels and prevents cell death
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10413358/
https://www.ncbi.nlm.nih.gov/pubmed/37394005
http://dx.doi.org/10.1016/j.jbc.2023.104999
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