Glibenclamide treatment modulates the expression and localization of myosin-IIB in diabetic rat brain.

Background: Myosin-IIB is a non-muscle isoform in the brain with increased expression in the brains of diabetic rats. Chronic hyperglycemia caused by diabetes can impair learning and memory. Oral hypoglycemic agents such as glibenclamide have been used to control hyperglycemia. We report changes in the expression and distribution of myosin-IIB in the frontal cortex and hippocampus of diabetic rats treated with glibenclamide.

Methods: The brains were removed after 43 days of treatment with glibenclamide (6 mg/kg bw orally), homogenized and analyzed by Western blotting, qRT-PCR and immunohistochemistry.

Results: Myosin-IIB expression increased in the brains of diabetic rats. However, protein expression returned to control levels when treated with glibenclamide. In addition, the expression of MYH10 gene encoding non-muscle myosin heavy chain-B decreased in diabetic rats treated with glibenclamide. Moreover, we found weak myosin-IIB labeling in the hippocampus and frontal cortex of rats treated with glibenclamide. Therefore, the expression of myosin-IIB is affected by diabetes mellitus and may be modulated by glibenclamide treatment in rats. Structural changes in the hippocampus and prefrontal cortex are reversible, and glibenclamide treatment may reduce the patho-physiological changes in the brain.

Conclusions: Our findings can contribute to the understanding of the regulation of myosins in the brains of diabetic rats.