O-GlcNAc stimulation is beneficial in septic shock in the young rat without affecting gene expression

Abstract

O-GlcNAcylation, a post-translational modification, has been associated with an improvement of the cell survival and the stress response through a modulation of gene expression. We have previously demonstrated that O-GlcNAc stimulation in different models of sepsis is associated with a reduction in mortality and an improvement of different biological markers. Evaluate how O-GlcNAcylation stimulation improves sepsis outcomes in young rats. Endotoxemic shock was induced in 28 days old rats by lipopolysaccharides injection (O111:B4, 20 mg.kg −1 ) and compared to control rats (NaCl 0.9%). One hour after lipopolysaccharides injection, rats were randomly assigned to no therapy (LPS), fluidotherapy (NaCl 0.9%, 10 mg.kg −1 -LPS + R) ± NButGT (10 mg.kg −1 ) to increase O-GlcNAc levels. Physiological functions were evaluated 2 hours later, as well as mortality over 36 hours. Cardiac O-GlcNAcylated proteins were mapped by untargeted mass spectrometry and compared to genes transcription via 3′ SRP analysis. The impact of O-GlcNAc has been evaluated on cardiac tissue and HL1 cells (Thiamet G (O-GlcNAc stimulator): 10-8 to 10-5 M). LPS induced a shock with a decrease in mean arterial pressure ( P < 0.05). LPS + R had no beneficial effect while NButGT improves mean arterial pressure and median time of survival ( P < 0.05). The mRNA expression was not impacted 2 hours after treatment in LPS + R and NButGT group. However, 33 proteins are differentially O-GlcNAcylated in all groups. Among them, 60% are involved in metabolism and metabolic pathways. ATP-citrate lyase (ACLY) a key enzyme in fatty acid biosynthesis, is the only protein less O-GlcNAcylated in the NButGT group. O-GlcNAc stimulation on HL1 cells increases expression of tetrameric form of ACLY ( P < 0.05). Acute O-GlcNAc stimulation improves outcome in young septic rat. Stimulate the O-GlcNAcylation increased cardiac O-GlcNAcylated proteins notably those involved in metabolic pathways. Surprisingly, the transcription is not impacted by the O-GlcNAc stimulation. Study the impact of the O-GlcNAcylation on the activity or the interactome of ACLY is one issue to decipher the involvment of the O-GlcNAcylation during sepsis.