Ketogenic diet exposure and glial cells: Exposure to beta-hydroxybutyrate induces morphological changes in astrocytes in vitro.

Ketogenic diet (KD) is an effective epilepsy treatment whose mechanisms remain unknown. We aimed to assess the effects of ketogenic diet on astrocytes. For that purpose, in silico analyses were performed on public databases showing that the transcriptomic signature of reactive astrocytes in vivo was deeply altered by KD. Specifically, inflammatory genes which as IL1a, C3, and Lcn2 expression were reduced by KD. In vitro, KD was mimicked by beta-Hydroxybutyrate (BHB) treatment (2.5 and 5.0 mM) on rat primary astrocytes exposed to a pro-inflammatory challenge. Cultures were obtained from 2-day-old postnatal rats and divided into 10 groups: Control, LPS, and BHB were added in a pretreatment/posttreatment scheme. Glucose in the culture medium was adjusted to 5.5 mM accordingly. Cells were stained with MitoSOX or GFAP to perform morphological studies. BHB treatment induced a dose-dependent increase in GFAP expression. Pretreatment with BHB (2.5 mM) significantly attenuated the LPS-induced increase in covered area, while posttreatment not only failed to restore astroglial morphology but increased it relative to LPS alone. MitoSox analysis showed that ROS levels were increased in BHB-treated astrocytes. These preliminary findings suggest that BHB exposure increases astrocytic reactivity and ROS, with dose-dependent effects on GFAP expression. Further studies are necessary to completely elucidate the profile of BHB effects on astrocytes and neurons. Grants: PIP CONICET, UBACYT.