Diabetes Differentially Alters Glial Cells in Different Brain Regions

Background/Objectives: The chronic metabolic condition of hyperglycemia in type-2 diabetics is known to cause various neurological disorders and compromise recovery from brain insults. Previously, we reported a delayed and reduced glial cell response and a greater neuronal cell death in different brain regions of diabetic, db/db, mice following cerebral hypoxic- ischemic injury. In this study, we explored the changes in baseline activation of astrocytes and microglia and its impact on vascular permeability in different brain regions. Methods: The numbers of activated astrocytes (GFAP-positive) and microglia/macrophage (Iba-1-positive) in the motor cortex, caudate and hippocampal regions of 12-week old, type-2 diabetic db/db and non-diabetic db/+ mice were quantitated. The leakage of serum IgG and loss of occludin, a tight junctional protein observed in the cortex and caudate of db/db mice, indicated a compromised blood brain barrier. Results: Results indicated significant differences in activation of glial cells in the cortex and caudate along with increased vessel permeability in diabetic mice. Conclusions: The study suggests that a constant activation of glial cells in the diabetic brain may be the cause of impaired inflammatory response and/or degenerating cerebral blood vessels which contribute to neuronal cell death upon CNS injury.