engleski

Sex specific changes in expression of major brain gangliosides in the hippocampi of middle- aged rats on Western diet

Gangliosides are sialic acid-containing glycosphingolipids found on the mammalian cell surface. They are involved in cell-cell interactions and in regulation of signaling pathways. Changes of their expression, because of environmental or genetic factors, might lead to neurological disorders. The aim of this study is to compare the expression of four major brain gangliosides in the hippocampi of healthy and obese diabetic rats. Both male and female Sprague-Dawley rats aged 10 months were included in the study. For 5 months the control group was fed with standard diet and experimental group with food rich in fats and carbohydrates. This type of diet led to obesity and development of type 2 diabetes (T2D). When the animals were 15 months old, the brains were collected and 35 µm-thick cryosections were prepared. The expression of GM1, GD1a, GD1b and GT1b was revealed in the hippocampus CA1 field and dentate gyrus (DG) using immunohistochemistry and was quantified using FIJI. In comparison to control group, the male experimental group had significantly less expressed GM1 within CA1 and DG (p=0.026 ; p=0.031), while in females its expression level was unaltered. Obese diabetic males had significantly more GD1b and GT1b in CA1 (p=0.001 ; p=0.0008) and GD1b in DG (p<0.0001). In obese diabetic females noted changes were opposite. There was significantly less GD1a and GD1b in both analyzed areas (CA1: p(GD1a)=0.021, p(GD1b)=0.0006 ; DG: p(GD1a)=0.0008, p(GD1b)<0.0001), and GT1b in CA1 (p=0.010). High calorie food, and resulting obesity and T2D, affect the expression of major brain gangliosides in sex specific manner. In males the expression of more complex gangliosides increases, but in females decreases.

type 2 diabetes ; hippocampus ; rat ; gangliosides ; Western diet

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