Role of gut microbiota in lead-induced neural damage in diabetic mice

Figure 1 Lead and blood glucose levels in different mice groups. A: Results of mouse brain levels; B and C: Blood glucose levels of mice in different groups at different time points. ^aP < 0.05 vs control group. ^bP < 0.05 vs diabetes group. ^cP < 0.05 vs lead exposure group. WTC: Control group; WTM: Diabetes group; WTH: Lead exposure group; WTMH: Diabetes with lead exposure group.

Figure 2 Immunofluorescence results. A: Expression of GFAP in the hippocampal tissue of each group of mice; B: Statistical analysis of average fluorescence intensity. ^aP < 0.05 vs control group. ^cP < 0.05 vs lead exposure group. WTC: Control group; WTM: Diabetes group; WTH: Lead exposure group; WTMH: Diabetes with lead exposure group.

Figure 3 Results of the Morris water maze experiment in mice. A: Escape latency period of each group of mice on the fifth day; B: Platform crossing frequency of each group of mice; C: Target quadrant time of each group of mice; D: Target quadrant swim distance of each group of mice; E: Representative figure of swimming trajectories of each group of mice in the spatial exploration test. Sample size: WTC: 20, WTM: 20, WTH: 20, WTMH: 20. ^aP < 0.05 vs control group. WTC: Control group; WTM: Diabetes group; WTH: Lead exposure group; WTMH: Diabetes with lead exposure group.

Figure 4 High performance liquid chromatography analysis of urinary neurotransmitters in mice. A: Vanillylmandelic acid; B: 5-Hydroxyindoleacetic acid; C: Homovanillic acid; D: 3,4-Dihydroxyphenylacetic acid. ^aP < 0.05 vs control group. WTC: Control group; WTM: Diabetes group; WTH: Lead exposure group; WTMH: Diabetes with lead exposure group; VMA: Vanillylmandelic acid; 5-HIAA: 5-Hydroxyindoleacetic acid; DOPAC: 3,4-Dihydroxyphenylacetic acid; HVA: Homovanillic acid.

Figure 5 Hippocampal proteomics results in mice from different groups. A: Differentially expressed proteins between control group (WTC) and diabetes group in proteomic analysis; B: Differentially expressed proteins between WTC and diabetes with lead exposure group in proteomic analysis; C and D: Top 10 differentially expressed genes in Gene Ontology biological process enrichment analysis; E and F: Top 10 differentially expressed genes in Kyoto Encyclopedia of Genes and Genomes enrichment analysis.

Figure 6 Detection of gut microbiota in different groups of mice and correlation analysis between gut microbiota and proteomics. A: Analysis of Chao1, observed species indices, Faith’s PD index, and Simpson diversity index; B: Microbial Venn diagram analysis of intergroup differences; C: Analysis of metabolic pathways of differential microbial communities; D: Correlation analysis between differential microbiota and top 60 differential proteins between control group and diabetes group; E: Correlation analysis between differential microbiota and top 60 differential proteins between control group and diabetes with lead exposure group.

Figure 7 Western blot and glutathione detection in hippocampal tissue of mice. A: Protein bands of each group of mice; B: Expression of OX2 protein; C: Expression of PI3K protein; D: Expression of AKT protein, E: Expression of glutathione in the brain of each group of mice. ^aP < 0.05 vs control group. ^cP < 0.05 vs lead exposure group. WTC: Control group; WTM: Diabetes group; WTH: Lead exposure group; WTMH: Diabetes with lead exposure group.