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Impact of Short-Term Hypoxia on Sirtuins as Regulatory Elements in HUVECs

Background: Sirtuins (SIRT) are NAD(+)-dependent deacetylases that are involved in stress response, antioxidative defense, and longevity via posttranslational modifications. SIRT1 directly activates nitric oxide synthase (NOS). Aging is associated with a reduced sirtuin function and reduction of the...

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Autores principales: Pecher, Simone Johanna, Potthast, Arne Björn, von Versen-Höynck, Frauke, Das, Anibh Martin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7464651/
https://www.ncbi.nlm.nih.gov/pubmed/32796661
http://dx.doi.org/10.3390/jcm9082604
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author Pecher, Simone Johanna
Potthast, Arne Björn
von Versen-Höynck, Frauke
Das, Anibh Martin
author_facet Pecher, Simone Johanna
Potthast, Arne Björn
von Versen-Höynck, Frauke
Das, Anibh Martin
author_sort Pecher, Simone Johanna
collection PubMed
description Background: Sirtuins (SIRT) are NAD(+)-dependent deacetylases that are involved in stress response, antioxidative defense, and longevity via posttranslational modifications. SIRT1 directly activates nitric oxide synthase (NOS). Aging is associated with a reduced sirtuin function and reduction of the cofactor NAD(+). Age-related atherosclerosis and vascular diseases are linked to a compromised sirtuin function. Vascular events like stroke and cardiac infarction result in acute hypoxia, which can additionally impact sirtuins and thus the vascular function. This prompted us to study sirtuins in intact HUVECs, under acute, short-term hypoxic conditions. Methods: We measured intracellular sirtuin and NAD(+) levels in HUVECs exposed to hypoxia (2% O₂) for 10–120 min, compared to normoxic controls. SIRT1, SIRT3, and SIRT4 were measured at the protein (Western Blot) and the transcript level (qRT-PCR), SIRT1 and SIRT3 at the enzyme level (fluorometrically), and NAD(+) levels were measured spectrophotometrically. Results: We observed a reduction of SIRT1 and SIRT4 at the protein level, a downregulation of SIRT1 at the transcript level and increased NAD(+) levels under hypoxia. SIRT3 was not affected by hypoxia. Conclusions: Downregulation of SIRT1 under hypoxia might reduce production of the reactive oxygen species (ROS) via the respiratory chain and inhibit the mitochondrial ATP-synthase, resulting in energy conservation. NOS might be impaired if SIRT1 is decreased. Increased NAD(+) levels might compensate these effects. Hypoxic downregulation of SIRT4 might lead to mitochondrial uncoupling, hence endothelial dysfunction, and ADP/ATP-translocase 2 (ANT2)-inhibition. NAD(+) upregulation might partly compensate this effect.
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spelling pubmed-74646512020-09-04 Impact of Short-Term Hypoxia on Sirtuins as Regulatory Elements in HUVECs Pecher, Simone Johanna Potthast, Arne Björn von Versen-Höynck, Frauke Das, Anibh Martin J Clin Med Article Background: Sirtuins (SIRT) are NAD(+)-dependent deacetylases that are involved in stress response, antioxidative defense, and longevity via posttranslational modifications. SIRT1 directly activates nitric oxide synthase (NOS). Aging is associated with a reduced sirtuin function and reduction of the cofactor NAD(+). Age-related atherosclerosis and vascular diseases are linked to a compromised sirtuin function. Vascular events like stroke and cardiac infarction result in acute hypoxia, which can additionally impact sirtuins and thus the vascular function. This prompted us to study sirtuins in intact HUVECs, under acute, short-term hypoxic conditions. Methods: We measured intracellular sirtuin and NAD(+) levels in HUVECs exposed to hypoxia (2% O₂) for 10–120 min, compared to normoxic controls. SIRT1, SIRT3, and SIRT4 were measured at the protein (Western Blot) and the transcript level (qRT-PCR), SIRT1 and SIRT3 at the enzyme level (fluorometrically), and NAD(+) levels were measured spectrophotometrically. Results: We observed a reduction of SIRT1 and SIRT4 at the protein level, a downregulation of SIRT1 at the transcript level and increased NAD(+) levels under hypoxia. SIRT3 was not affected by hypoxia. Conclusions: Downregulation of SIRT1 under hypoxia might reduce production of the reactive oxygen species (ROS) via the respiratory chain and inhibit the mitochondrial ATP-synthase, resulting in energy conservation. NOS might be impaired if SIRT1 is decreased. Increased NAD(+) levels might compensate these effects. Hypoxic downregulation of SIRT4 might lead to mitochondrial uncoupling, hence endothelial dysfunction, and ADP/ATP-translocase 2 (ANT2)-inhibition. NAD(+) upregulation might partly compensate this effect. MDPI 2020-08-11 /pmc/articles/PMC7464651/ /pubmed/32796661 http://dx.doi.org/10.3390/jcm9082604 Text en © 2020 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
Pecher, Simone Johanna
Potthast, Arne Björn
von Versen-Höynck, Frauke
Das, Anibh Martin
Impact of Short-Term Hypoxia on Sirtuins as Regulatory Elements in HUVECs
title Impact of Short-Term Hypoxia on Sirtuins as Regulatory Elements in HUVECs
title_full Impact of Short-Term Hypoxia on Sirtuins as Regulatory Elements in HUVECs
title_fullStr Impact of Short-Term Hypoxia on Sirtuins as Regulatory Elements in HUVECs
title_full_unstemmed Impact of Short-Term Hypoxia on Sirtuins as Regulatory Elements in HUVECs
title_short Impact of Short-Term Hypoxia on Sirtuins as Regulatory Elements in HUVECs
title_sort impact of short-term hypoxia on sirtuins as regulatory elements in huvecs
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7464651/
https://www.ncbi.nlm.nih.gov/pubmed/32796661
http://dx.doi.org/10.3390/jcm9082604
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