Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides.

Reverse transcription followed by quantitative (real-time) polymerase chain reaction (RT-qPCR) has become the gold standard in mRNA expression analysis. However, it requires an accurate choice of reference genes for adequate normalization. The aim of this study was to validate the reference genes fo...

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Main Authors: Alexander P Schwarz, Veronika A Nikitina, Darya U Krytskaya, Ksenia P Shcherbakova, Alexander N Trofimov
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2023-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0273224
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author Alexander P Schwarz
Veronika A Nikitina
Darya U Krytskaya
Ksenia P Shcherbakova
Alexander N Trofimov
author_facet Alexander P Schwarz
Veronika A Nikitina
Darya U Krytskaya
Ksenia P Shcherbakova
Alexander N Trofimov
author_sort Alexander P Schwarz
collection DOAJ
description Reverse transcription followed by quantitative (real-time) polymerase chain reaction (RT-qPCR) has become the gold standard in mRNA expression analysis. However, it requires an accurate choice of reference genes for adequate normalization. The aim of this study was to validate the reference genes for qPCR experiments in the brain of rats in the model of mild ketosis established through supplementation with medium-chain triglycerides (MCT) and intermittent fasting. This approach allows to reproduce certain neuroprotective effects of the classical ketogenic diet while avoiding its adverse effects. Ketogenic treatment targets multiple metabolic pathways, which may affect the reference gene expression. The standard chow of adult Wistar rats was supplemented with MCT (2 ml/kg orogastrically, during 6 h of fasting) or water (equivolume) for 1 month. The mRNA expression of 9 housekeeping genes (Actb, B2m, Gapdh, Hprt1, Pgk1, Ppia, Rpl13a, Sdha, Ywhaz) in the medial prefrontal cortex, dorsal and ventral hippocampus was measured by RT-qPCR. Using the RefFinder® online tool, we have found that the reference gene stability ranking strongly depended on the analyzed brain region. The most stably expressed reference genes were found to be Ppia, Actb, and Rpl13a in the medial prefrontal cortex; Rpl13a, Ywhaz, and Pgk1 in the dorsal hippocampus; Ywhaz, Sdha, and Ppia in the ventral hippocampus. The B2m was identified as an invalid reference gene in the ventral hippocampus, while Sdha, Actb, and Gapdh were unstable in the dorsal hippocampus. The stabilities of the examined reference genes were lower in the dorsal hippocampus compared to the ventral hippocampus and the medial prefrontal cortex. When normalized to the three most stably expressed reference genes, the Gapdh mRNA was upregulated, while the Sdha mRNA was downregulated in the medial prefrontal cortex of MCT-fed animals. Thus, the expression stability of reference genes strongly depends on the examined brain regions. The dorsal and ventral hippocampal areas differ in reference genes stability rankings, which should be taken into account in the RT-qPCR experimental design.
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spelling doaj.art-959854423b2e48b7ac3c6c51c262cc7c2023-02-15T05:31:17ZengPublic Library of Science (PLoS)PLoS ONE1932-62032023-01-01182e027322410.1371/journal.pone.0273224Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides.Alexander P SchwarzVeronika A NikitinaDarya U KrytskayaKsenia P ShcherbakovaAlexander N TrofimovReverse transcription followed by quantitative (real-time) polymerase chain reaction (RT-qPCR) has become the gold standard in mRNA expression analysis. However, it requires an accurate choice of reference genes for adequate normalization. The aim of this study was to validate the reference genes for qPCR experiments in the brain of rats in the model of mild ketosis established through supplementation with medium-chain triglycerides (MCT) and intermittent fasting. This approach allows to reproduce certain neuroprotective effects of the classical ketogenic diet while avoiding its adverse effects. Ketogenic treatment targets multiple metabolic pathways, which may affect the reference gene expression. The standard chow of adult Wistar rats was supplemented with MCT (2 ml/kg orogastrically, during 6 h of fasting) or water (equivolume) for 1 month. The mRNA expression of 9 housekeeping genes (Actb, B2m, Gapdh, Hprt1, Pgk1, Ppia, Rpl13a, Sdha, Ywhaz) in the medial prefrontal cortex, dorsal and ventral hippocampus was measured by RT-qPCR. Using the RefFinder® online tool, we have found that the reference gene stability ranking strongly depended on the analyzed brain region. The most stably expressed reference genes were found to be Ppia, Actb, and Rpl13a in the medial prefrontal cortex; Rpl13a, Ywhaz, and Pgk1 in the dorsal hippocampus; Ywhaz, Sdha, and Ppia in the ventral hippocampus. The B2m was identified as an invalid reference gene in the ventral hippocampus, while Sdha, Actb, and Gapdh were unstable in the dorsal hippocampus. The stabilities of the examined reference genes were lower in the dorsal hippocampus compared to the ventral hippocampus and the medial prefrontal cortex. When normalized to the three most stably expressed reference genes, the Gapdh mRNA was upregulated, while the Sdha mRNA was downregulated in the medial prefrontal cortex of MCT-fed animals. Thus, the expression stability of reference genes strongly depends on the examined brain regions. The dorsal and ventral hippocampal areas differ in reference genes stability rankings, which should be taken into account in the RT-qPCR experimental design.https://doi.org/10.1371/journal.pone.0273224
spellingShingle Alexander P Schwarz
Veronika A Nikitina
Darya U Krytskaya
Ksenia P Shcherbakova
Alexander N Trofimov
Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides.
PLoS ONE
title Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides.
title_full Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides.
title_fullStr Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides.
title_full_unstemmed Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides.
title_short Reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium-chain triglycerides.
title_sort reference gene expression stability within the rat brain under mild intermittent ketosis induced by supplementation with medium chain triglycerides
url https://doi.org/10.1371/journal.pone.0273224
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