Effects of short-chain fatty acids on gut microbiota and hippocampal TLR4/MyD88/NF-κB pathway proteins in depression model mice
10.3760/cma.j.cn371468-20231209-00295
- VernacularTitle:短链脂肪酸对抑郁模型小鼠肠道菌群及海马TLR4/MyD88/NF-κB通路蛋白的影响
- Author:
Wenjuan HAN
1
;
Yaxin ZHENG
;
Lan WANG
;
Fengya ZHEN
;
Yan ZHANG
;
Cuixia AN
Author Information
1. 河北医科大学第二医院精神心理科，石家庄 050005
- Keywords:
Depression;
Short-chain fatty acids;
Inflammation;
Gut microbiota;
Chronic unpredictable mild stress;
Mouse
- From:
Chinese Journal of Behavioral Medicine and Brain Science
2024;33(7):583-589
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate whether short chain fatty acid(SCFAs) intervention has an antidepressant effect by improving gut microbiota dysregulation and regulating the TLR4/MyD88/NF-κB inflammatory pathway in depression model mice.Methods:Totally 60 SPF grade male C57BL/6 J mice aged 6-8 weeks were randomly divided into three groups: control group, depression model group, and SCFAs group, with 20 mice in each group.The mice in depression model group and SCFAs group were given the chronic unpredictable mild stress (CUMS) stimulations for 8 weeks to establish the depression model.From the 6th week, SCFAs group mice were given a mixed solution of short chain fatty acid salts for drinking, until modeling was completed, meanwhile mice in the model group were given 0.78% NaCl solution for drinking.The depression-like behavior was assessed using the sucrose preference test (SPT) and forced swimming test (FST) following modeling, and the open field test (OFT) was employed to evaluate the anxiety-like behavior of mice.16S rRNA gene sequence was used to analyze the gut microbiota of mice.The activation of astrocytes and TLR4/MyD88/NF-κB inflammatory pathway in hippocampus was determined by immunofluorescence staining and Western blot.SPSS 26.0 was used for statistical analysis, one-way ANOVA was used for comparison among the three groups, and LSD- t test was used for further pairwise comparisons. Results:There were statistically significant differences in the sugar water preference rate, the immobility time in FST, and the percentage of activity time in OFT among the three groups ( F=10.554, 10.912, 12.599, all P<0.05).The the sugar water preference rate and the percentage of activity time in OFT of the depression model group were both lower than those of the control group (both P<0.05), and the immobility time in FST was higher than that of the control group ( P<0.05).The sugar water preference rate in SCFAs group((84.7±3.5)%, (75.3±6.0)%)and the percentage of activity time in OFT((7.4±1.4)%, (3.2±0.9)%) were both higher than those in the depression model group(both P<0.05 ), while the immobility time in FST was shorter than that in the depression model group((110.5±21.5) s, (148.0±20.1) s, P<0.05).There was a statistical difference in the β diversity of gut microbiota among three groups ( P=0.001).At the family level, compared with the depression model group, the relative abundance of Rikenellaceaee and Bacteroidaceae increased in the SCFAs group, while the relative abundance of Clostridia_UCG-014 decreased.At the genus level, the relative abundance of Clostridia_UCG-014 and Prevotella decreased, while the relative abundance of Alistipes increased (all P<0.05).The immunofluorescence results showed that there was a statistically significant difference in GFAP expression levels among the three groups of mice ( F=16.565, P=0.004).The GFAP expression in the depression model group was higher than that in the control group and SCFAs group (both P<0.05).The Western blot results showed that there were statistically significant differences in the expression levels of TLR4, MYD88, and NF-κB ptoteins in the hippocampal tissue of the three groups ( F=70.59, 174.39, 14.40, all P<0.05).The protein levels of TLR4, MyD88, and NF-κB in the depression model group were all higher than those in the control group and SCFAs group (all P<0.05). Conclusion:SCFAs can ameliorate the depressive-like behavior in depression model mice and reduce the activation of astrocytes in the hippocampus, which may be associated with the improvement of dysregulated gut microbiota and down-regulation of the TLR4/MyD88/NF-κB pathway protein.
