AUTHOR=Di Cerbo Alessandro , Roncati Luca , Marini Carlotta , Carnevale Gianluca , Zavatti Manuela , Avallone Rossella , Corsi Lorenzo 

TITLE=Possible Association Between DHEA and PKCε in Hepatic Encephalopathy Amelioration: A Pilot Study

JOURNAL=Frontiers in Veterinary Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.695375

DOI=10.3389/fvets.2021.695375

ISSN=2297-1769

ABSTRACT=<p><bold>Objective:</bold> Hepatic encephalopathy (HE) is a neuropsychiatric syndrome caused by liver failure and by an impaired neurotransmission and neurological function caused by hyperammonemia (HA). HE, in turn, decreases the phosphorylation of protein kinase C epsilon (PKCε), contributing to the impairment of neuronal functions. Dehydroepiandrosterone (DHEA) exerts a neuroprotective effect by increasing the GABAergic tone through GABA<sub>A</sub> receptor stimulation. Therefore, we investigated the protective effect of DHEA in an animal model of HE, and the possible modulation of PKCε expression in different brain area.</p><p><bold>Methods:</bold> Fulminant hepatic failure was induced in 18 male, Sprague–Dawley rats by i.p. administration of 3 g/kg D-galactosamine, and after 30 min, a group of animals received a subcutaneous injection of 25 mg/kg (DHEA) repeated twice a day (3 days). Exploratory behavior and general activity were evaluated 24 h and 48 h after the treatments by the open field test. Then, brain cortex and cerebellum were used for immunoblotting analysis of PKCε level.</p><p><bold>Results:</bold> DHEA administration showed a significant improvement of locomotor activity both 24 and 48 h after D-galactosamine treatment (<sup>****</sup><italic>p</italic> &lt; 0.0001) but did not ameliorate liver parenchymal degeneration. Western blot analysis revealed a reduced immunoreactivity of PKCε (<sup>*</sup><italic>p</italic> &lt; 0.05) following D-galactosamine treatment in rat cortex and cerebellum. After the addition of DHEA, PKCε increased in the cortex in comparison with the D-galactosamine-treated (<sup>***</sup><italic>p</italic> &lt; 0.001) and control group (<sup>*</sup><italic>p</italic> &lt; 0.05), but decreased in the cerebellum (<sup>*</sup><italic>p</italic> &lt; 0.05) with respect to the control group. PKCε decreased after treatment with NH<sub>4</sub>Cl alone and in combination with DHEA in both cerebellum and cortex (<sup>****</sup><italic>p</italic> &lt; 0.0001). MTS assay demonstrated the synergistic neurotoxic action of NH<sub>4</sub>Cl and glutamate pretreatment in cerebellum and cortex along with an increased cell survival after DHEA pretreatment, which was significant only in the cerebellum (<sup>*</sup><italic>p</italic> &lt; 0.05).</p><p><bold>Conclusion:</bold> An association between the DHEA-mediated increase of PKCε expression and the improvement of comatose symptoms was observed. PKCε activation and expression in the brain could inhibit GABA-ergic tone counteracting HE symptoms. In addition, DHEA seemed to ameliorate the symptoms of HE and to increase the expression of PKCε in cortex and cerebellum.</p>