Objective: To investigates the role of Wnt/β-catenin signaling pathway in the phenotypic transformation
of astrocytes in diabetic encephalopathy. Methods: A diabetic mouse model was established by feeding the mice with
high-fat diet for 12 weeks. Twelve C57BL/6 mice were randomly divided into control group and diabetic groups.
The blood glucose level and body weight of the mice were detected at 0 and 12 weeks. Immunofluorescence was
used to detect the expression of A1 astrocyte marker C3 and A2 astrocyte marker S100A10 in the hippocampus. C8-
D1A astrocyte cell line was used to establish three groups: control, palmitic acid (PA)-treated, and PA+Wnt pathway
activator (SKL2001). cell viability at various PA concentrations (0, 50, 100, 200, 300 μmol/L) was assessed through
the CCK-8 assay. Lipid accumulation in C8-D1A astrocytes was evaluated by using Oil Red O staining. Western
blotting analysis was performed to measure the protein
expression levels of GFAP, C3, S100A10, Wnt3a,
β-catenin, p-GSK3β and GSK3β. Immunofluorescencewas used to visualize the expression of C3/GFAP, S100A10/GFAP, Wnt3a and β-catenin in astrocytes. Results:
Compared with the control group, the blood glucose level and body weight of the diabetic group were significantly
increased. The fluorescence intensity of C3 in the hippocampus of diabetic mice was significantly higher than that of
the control group, but the fluorescence intensity of S100A10 was not significantly different between the two groups.
Compared with the control group, PA treatment significantly inhibited the cell viability in a concentration-dependent
manner. Oil Red O staining showed orange-red lipid droplets in the cytoplasm of C8-D1A cells in PA-treated groups.
Western blotting results showed that the protein expressions of GFAP and C3 in the PA group were significantly
higher than those in the control group, while the protein expressions of Wnt3a, β-catenin, and p-GSK3β/GSK3β in
the PA group were significantly lower than those in the control group. In the PA+SKL2001 group, SKL2001 partially
reversed the PA-induced changes in protein expression. No significant differences were found in S100A10 protein
expression among the three groups. Immunofluorescence results confirmed that compared with the control group,
the fluorescence intensity of C3/GFAP in the PA group was increased. Compared with the PA group, the fluorescence
intensity of C3/GFAP was decreased in the PA+SKL2001 group, while the fluorescence intensity of S100A10 did not
differ significantly between groups. Compared with the control group, the fluorescence intensity of Wnt3a and the
translocation of β-catenin into the nucleus in the PA group decreased. Compared with the PA group, both indicators
above were increased in the PA+SKL2001 group. Conclusion: In diabetic encephalopathy, the transformation of
astrocyte phenotype may be caused by inhibiting the expression of Wnt/β-catenin signaling pathway-related proteins,
leading to the transformation of astrocytes into type A1, thereby exacerbating disease progression.
