Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Feb;41(2):267-281.
doi: 10.1177/0271678X20910533. Epub 2020 Mar 9.

Sodium butyrate attenuated neuronal apoptosis via GPR41/Gβγ/PI3K/Akt pathway after MCAO in rats

Zhenhua Zhou  1   2 , Ningbo Xu  2   3 , Nathanael Matei  2 , Devin W McBride  4 , Yan Ding  2 , Hui Liang  2 , Jiping Tang  2 , John H Zhang  2
Affiliations

Sodium butyrate attenuated neuronal apoptosis via GPR41/Gβγ/PI3K/Akt pathway after MCAO in rats

Zhenhua Zhou et al. J Cereb Blood Flow Metab. 2021 Feb.

Abstract

Sodium butyrate, a short-chain fatty acid, is predominantly produced by gut microbiota fermentation of dietary fiber and serves as an important neuromodulator in the central nervous system. Recent experimental evidence has suggested that sodium butyrate may be an endogenous ligand for two orphan G protein-coupled receptors, GPR41 and GP43, which regulate apoptosis and inflammation in ischemia-related pathologies, including stroke. In the present study, we evaluated the potential efficacy and mechanism of action of short-chain fatty acids in a rat model of middle cerebral artery occlusion (MCAO). Fatty acids were intranasally administered 1 h post MCAO. Short-chain fatty acids, especially sodium butyrate, reduced infarct volume and improved neurological function at 24 and 72 h after MCAO. At 24 h, the effects of MCAO, increased apoptosis, were ameliorated after treatment with sodium butyrate, which increased the expressions of GPR41, PI3K and phosphorylated Akt. To confirm these mechanistic links and characterize the GPR active subunit, PC12 cells were subjected to oxygen-glucose deprivation and reoxygenation, and pharmacological and siRNA interventions were used to reverse efficacy. Taken together, intranasal administration of sodium butyrate activated PI3K/Akt via GPR41/Gβγ and attenuated neuronal apoptosis after MCAO.

Keywords: GPR41; MCAO; PI3K/Akt; Short-chain fatty acid; apoptosis; butyrate.

PubMed Disclaimer

Conflict of interest statement

Declaration of conflicting interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Intranasal administration of NaB reduced infract volume and improved neurological deficits at 24 h after MCAO in rats. (a) Representative images of TTC-stained brain slices at 24 h after MCAO. (b) Quantified infarct volume, (c) Modified Garcia Score, and (d) Beam Balance Score showed NaB (medium (7.5 mg/kg) and high doses (22.5 mg/kg)) significantly decreased infarction and neurological deficits. Data are presented as mean ± SD. n = 6 for each group. *p < 0.05 versus Sham, #p < 0.05 versus MCAO + Vehicle, @p < 0.05 versus MCAO + 2.5 mg/kg NaB, &p < 0.05 versus MCAO + 7.5 mg/kg NaB.
Figure 2.
Figure 2.
Expression profiles of endogenous GPR41, PI3K, p-Akt and Akt after MCAO in rats. (a) Representative Western blot bands of time course and (b–d) quantitative analyses of endogenous GPR41, PI3K, p-Akt and Akt after MCAO. Data are presented as mean ± SD. n = 6 for each group, *p < 0.05 versus Sham. (e) Double immunostaining of GPR41 with neurons (NeuN), astrocytes (GFAP) and microglia (IBA1) at 24 h after MCAO. Samples were obtained from ischemic penumbra 24 h following MCAO. White arrows indicate the cell shown in the higher magnification box or GPR41-positive neurons (Scale bar: 50 µm). n = 3 for each group.
Figure 3.
Figure 3.
NaB improved long-term neurological function at four weeks after MCAO in rats. (a) Treatment with NaB improved memory and learning abilities compared to the MCAO + Vehicle group as seen in a decreased escape latency, and an increased duration spent in the platform quadrant. Data are presented as mean ± SD. n = 8 for each group. *p < 0.05 versus Sham, #p < 0.05 versus MCAO + Vehicle.
Figure 4.
Figure 4.
Comparison of infarct volume and neurological scores after giving the GPR41 siRNA and PI3K inhibitor LY294002 at 24 h after MCAO in rats. (a) Representative image of TTC-stained brain slices. (b) Infarct volume and (c) Modified Garcia Score and (d) Beam Balance Score showed that GPR41 siRNA and PI3K inhibitor LY294002 inhibited the neuroprotective properties of NaB, and there were no differences between these two inhibitor groups. Data are presented as mean ± SD. n = 6 for each group. *p < 0.05 versus Sham, #p < 0.05 versus MCAO + Vehicle or MCAO + GPR41 siRNA, @p < 0.05 versus MCAO + NaB or MCAO + NaB+Scramble siRNA, &p < 0.05 versus MCAO + NaB or MCAO + NaB + DMSO.
Figure 5.
Figure 5.
NaB attenuated neuronal apoptosis via the GPR41/PI3K signaling pathway at 24 h after MCAO. (a) Representative Western blot images and quantitative analyses of GPR41 (b), PI3K (c), p-Akt/Akt (d), Bax (e) and C-Cas3/Cas3 (f) after treatment with either NaB or NaB + GPR41 siRNA, NaB + Scramble siRNA, NaB + LY294002, NaB + DMSO. (g) Representative images of Fluoro-Jade C (green, upper line), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL, red; NeuN, Green; middle line) and Cleaved Caspase3 (C-Cas3) (C-Cas3, red; NeuN, Green)-positive staining neurons in the ipsilateral cortex (Scale bar: 100 µm). (h–j) Quantification of Fluoro-Jade C, TUNEL and C-Cas3-positive neurons in the injured cortex. Data are presented as mean ± SD. n = 6 for each group. *p < 0.05 versus Sham, #p < 0.05 versus MCAO + Vehicle, @p < 0.05 versus MCAO + NaB or MCAO + NaB+Scramble siRNA, &p < 0.05 versus MCAO + NaB or MCAO + NaB + DMSO.
Figure 6.
Figure 6.
NaB attenuated OGD/R-induced oxidative injury via GPR41/Gβγ/PI3K/Akt pathway in PC12 cells. (a) Cell viability, measured by a CCK-8 assay, evaluated the efficacy of alternative NaB doses. Data are presented as mean ± SD. n = 6 for each group. *p < 0.05 versus Control, #p < 0.05 versus OGD/R, @p < 0.05 versus OGD/R + vehicle or OGD/R + 0.25 mmol/L NaB. (b) Cell viability was used to evaluate downstream mechanisms with the following interventions: NaB, NaB + GPR41 siRNA, NaB + scramble siRNA, NaB + NF023, and NaB + Gallein, NaB + LY294002, NaB + DMSO. Data are presented as mean ± SD. n = 6 for each group. *p < 0.05 versus Control or NaB, #p < 0.05 versus OGD/R + Vehicle, @p < 0.05 versus OGD/R + NaB or OGD/R + NaB + scramble siRNA, &p < 0.05 versus OGD/R + NaB or OGD/R + NaB + DMSO. (c) Immunofluorescence staining representative of GPR41 (red) and NeuN (Green) in PC12 cells, 24 h after OGD/R in Control, OGD/R + Vehicle, OGD/R + NaB, OGD/R + NaB + GPR41 siRNA and OGD/R + NaB+scramble siRNA groups (Scale bar: 50 µm).
Figure 7.
Figure 7.
NaB-induced phosphorylation of Akt was dependent on the Gβγ Subunit of GPR41 in vitro. (a) Representative pictures of Western blot bands showing the expression of GPR41, PI3K, p-Akt/Akt, Bax and C-Cas3/Cas3 after treatment with NaB, NaB+GPR41 siRNA, NaB+Scramble siRNA, NaB+NF023 and NaB+Gallein, NaB+LY294002, NaB+DMSO. (b–f) Quantification of Western blot data. Data are presented as mean ± SD. n = 6 for each group. *p < 0.05 versus Control, #p < 0.05 versus OGD/R+Vehicle, @p < 0.05 versus OGD/R+NaB or OGD/R+NaB+scramble siRNA, &p < 0.05 versus OGD/R+NaB or OGD/R+NaB+DMSO.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Murray CJ, Vos T, Lozano R, et al.. Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet 2012; 380: 2197–223. - PubMed
    1. Lozano R, Naghavi M, Foreman K, et al.. Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet 2012; 380: 2095–2128. - PMC - PubMed
    1. Gilgun-Sherki Y, Rosenbaum Z, Melamed E, et al.. Antioxidant therapy in acute central nervous system injury: current state. Pharmacol Rev 2002; 54: 271–284. - PubMed
    1. Candelario-Jalil E.Injury and repair mechanisms in ischemic stroke: considerations for the development of novel neurotherapeutics. Curr Opin Investig Drugs 2009; 10: 644–654. - PubMed
    1. Radak D, Katsiki N, Resanovic I, et al.. Apoptosis and acute brain ischemia in ischemic stroke. Curr Vasc Pharmacol 2017; 15: 115–122. - PubMed

Publication types

LinkOut - more resources

-