GRID2 Aberration Leads to Disturbance in Neuroactive Ligand-Receptor Interaction via Affecting the Species Richness and Composition of the Gut Microbes

Objective: Exploring the association of phenotypes (e.g. cerebellar ataxia, Alzheimer's disease, etc.) with the gut microbiome following damage to the GRID2 gene. Methods: Ten wild-type (WT)mice and 11 GRID2 knockout heterozygous mice (GRID2(+/-)) were randomly selected at 3 months of age with similar body weight, and fresh feces were collected from both groups of mice at 3 months of age under specified pathogen free (SPF). The bacterial genomes were extracted from the feces, the 16S rRNA genes were sequenced, and the data were analyzed for clustering, diversity, abundance, LEfSe and functional differences. Differential expression and enrichment analyses on RNA-seq and protein levels of GRID2 gene were also performed using data in GENE database and the new version of Human Protein Atlas portal (www.proteinatlas.org). Results: Diversity analysis showed that there were differences in species composition between the two groups at different levels. At the phylum level, compared to the WT group, the distribution was more in bacteriophages but less in the Tenericutes in the GRID2(+/-) group; at the order level, compared to the WT group, the Actinomycetales and the Bacteriophages were more distributed in the GRID2(+/-) group. Species difference analysis showed that the two groups differed in 17 species such as E. faecalis and Paracoccus spp. LEfSe analysis showed that the abundance of Clostridiaceae, Allobaculum and other groups decreased in the GRID2(+/-) group compared to the WT group, while Mycoplasma, Sphingomonas and Alphaproteobacteria increased in abundance. Functional analysis revealed eight differential functions between WT and GRID2(+/-) group (P <0.05). Among which, the most significant was disrupted neuroactive ligand-receptor interactions (P <9.99e-4). In addition, differential expression and enrichment analyses at RNA-seq and protein levels revealed that the GRID2 gene showed organ-specific expression and was mainly enriched in brain tissue. Conclusions：Compared to the WT group, the impaired GRID2 gene affected the species richness and composition of the gut microbes in GRID2(+/-) mice, which in turn affected the function of the gut microbes, leading to disrupted neuroactive ligand-receptor interactions. Our findings indicate that host gene GRID2 can influence the abundance of a subset of gut microbes, but the exact mechanism(s) still needs further investigation.Funding This work was supported by the National Natural Science Foundation of China (No. 82160537, 81770759, 81472414, 81560608 and 81460388), the Guangxi Natural Science Foundation (No. 2015GXNSFBB139008), Guangxi Key Research and Development Project (Grant No. Guike 2021AB12013), the Guangxi Colleges and Universities Key Laboratory of Biological Molecular Medicine Research Foundation (No. GXBMR201603) and the Guangxi key Laboratory for Genomic and Personalized Medicine (No. 16-380-54, 17-259-45, 19-050-22, 19-185-33, 20-065-33). The funding bodies played no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.Declaration of Interest: The authors declare no competing interests.Ethical Approval: The study was approved by the Experimental Animal Management andEthics Committee of Guangxi Medical University.