The Effect of Risperidone on the Expression of the St8sia2 and St8sia4 Genes and Its Effect on the Glycocalyx Layer in the Brain Tissues of Embryos and Newborn Albino Rats

Abstract

The present study investigated the effects of maternal exposure to sulforaphane (SFN) and risperidone (RIS) during pregnancy and the early postnatal period on the expression of the sialyltransferase genes St8sia2 and St8sia4 and the histological characteristics of developing rat brain tissue at embryonic day 14 (E14), the day of birth (P0), and postnatal day 7 (P7).
Histological examination using PAS staining revealed positive staining in all experimental groups, particularly in the intercellular matrix, neuronal membranes, and vascular structures, consistent with the presence of glycoprotein-rich components in developing brain tissue. At E14, the Saline group exhibited an organized cellular architecture with developing neurons and precursor cells, whereas the SFN group showed a more intense PAS reaction. The RIS group also demonstrated a positive PAS reaction with staining of the developing interstitial matrix and migrating neuronal cells. RT-qPCR results showed differences in the expression levels of the St8sia2 and St8sia4 genes among the experimental groups across the developmental stages. For St8sia2, no significant differences were observed between the Saline and SFN groups at any stage, whereas significant differences were detected between the RIS and SFN groups at E14 (P = 0.0488), between the Saline and RIS groups at P0 (P = 0.0327), and between the RIS and SFN groups (P = 0.0015). At P7, significant differences were observed between the Saline and RIS groups (P = 0.0012) and between the RIS and SFN groups (P = 0.0001). For St8sia4, no significant differences were observed among the experimental groups at E14 or P0, whereas significant differences were detected at P7 between the Saline and RIS groups (P = 0.0139) and between the RIS and SFN groups (P = 0.0004).
Conclusion: Maternal exposure to risperidone was associated with a significant reduction in St8sia2 gene expression at P0 and P7 and in St8sia4 expression at P7, compared with the Saline and/or SFN groups. In contrast, sulforaphane did not produce significant changes in the expression of either gene compared with the control group. PAS staining confirmed the presence of glycoprotein-rich components in developing brain tissue across all groups, with differences in staining intensity.