An O-GlcNAcylomic Approach Reveals ACLY as a Potential Target in Sepsis in the Young Rat

Abstract

Sepsis in the young population, which is particularly at risk, is rarely studied. O-GlcNAcylation is a post-translational modification involved in cell survival, stress response and metabolic regulation. O-GlcNAc stimulation is beneficial in adult septic rats. This modification is physiologically higher in the young rat, potentially limiting the therapeutic potential of O-GlcNAc stimulation in young septic rats. The aim is to evaluate whether O-GlcNAc stimulation can improve sepsis outcome in young rats. Endotoxemic challenge was induced in 28-day-old rats by lipopolysaccharide injection (E. Coli O111:B4, 20 mg·kg−1) and compared to control rats (NaCl 0.9%). One hour after lipopolysaccharide injection, rats were randomly assigned to no therapy, fluidotherapy (NaCl 0.9%, 10 mL·kg−1) ± NButGT (10 mg·kg−1) to increase O-GlcNAcylation levels. Physiological parameters and plasmatic markers were evaluated 2h later. Finally, untargeted mass spectrometry was performed to map cardiac O-GlcNAcylated proteins. Lipopolysaccharide injection induced shock with a decrease in mean arterial pressure and alteration of biological parameters (p < 0.05). NButGT, contrary to fluidotherapy, was associated with an improvement of arterial pressure (p < 0.05). ATP citrate lyase was identified among the O-GlcNAcylated proteins. In conclusion, O-GlcNAc stimulation improves outcomes in young septic rats. Interestingly, identified O-GlcNAcylated proteins are mainly involved in cellular metabolism.

Beneficial Effects of O-GlcNAc Stimulation in a Young Rat Model of Sepsis: Beyond Modulation of Gene Expression

“…As described in previous studies, O-GlcNAc stimulation is beneficial in septic shock in both adults and pup rats [ 13 , 14 ]. Yet, the mechanisms associated with the protective effects are not completely elucidated and remain to be understood.…”

“…Our model of septic shock has been studied previously and depicted a decrease in the mean arterial pressure and an increase in lactatemia and mortality in young rats. The administration of 10 mg/kg of NButGT (1,2-dideoxy-2′-propyl-α-d-glucopyranoso-[2,1-d]-Δ2′-thiazoline) [ 15 ] improves both mean arterial pressure and the median time of survival compared to rats treated with fluidotherapy (LPS + R) [ 14 ]. Although the O-GlcNAc stimulation is beneficial in young rats with septic shock, the mechanisms by which the O-GlcNAcylation acts remain unknown.…”

“…Male Wistar Han rats (Charles River, Saint-Germain-Nuelles, France) were housed under standard conditions of temperature (21–24 °C), humidity (40–60%) and a 12 h light/dark cycle with the light period starting at 07:00 a.m. Food and water were available ad libitum. Endotoxemic shock was induced in 28-days-old Wistar Han rats and compared to control rats (injection of NaCl 0.9%—CTRL) as previously described [ 14 ]. One hour after LPS injection, the rats were randomly assigned to no therapy (LPS) or fluidotherapy (NaCl 0.9%, 10 mL/kg—LPS + R) ± NButGT (NButGT, 10 mg/kg—NButGT) to increase O-GlcNAcylation levels ( Figure 6 ).…”

“…Western blotting experiments were performed as previously described [ 14 ]. Analysis was performed using Image Lab software (Image Lab 6.1, Bio-Rad, CA, USA).…”

“…Ferron and collaborators demonstrated that acute pharmacological stimulation of O-GlcNAc is protective in a lipopolysaccharide (LPS) and cecal ligation and puncture (CLP) adult rat model [ 13 ]. Furthermore, a study focusing on the impact of the treatment of septic shock in young animals highlighted that, despite higher basal levels of O-GlcNAcylation in young rats, increasing these levels is beneficial in this population too [ 14 ].…”