Resuscitation fluid composition affects hepatic inflammation in a murine model of early sepsis

MicroRNA-365 regulates the occurrence and immune response of sepsis following multiple trauma via interleukin-6

In the present study, the expression of microRNA (miR)-365 and interleukin (IL)-6 in peripheral blood mononuclear cells and serum from patients with sepsis following multiple trauma has been investigated. A total of 26 patients with sepsis following multiple trauma were included as the experimental group, whereas 21 contemporaneous patients without sepsis following multiple trauma were included as the negative control group. The expression of IL-6 mRNA and miR-365 was determined by reverse transcription-quantitative polymerase chain reaction, and western blot analysis was used to measure IL-6 protein expression. ELISA was performed to determine the secretion of IL-6 protein. Following stimulation with lipopolysaccharide (LPS) for 24 h, THP-1 cells were used to examine the expression of miR-365 and the levels of IL-6 protein and mRNA in cells simulating sepsis. A dual luciferase reporter assay revealed that IL-6 mRNA was a direct target of miR-365. Patients with sepsis following multiple trauma exhibited significantly higher IL-6 mRNA and protein levels than patients without sepsis (P<0.05). In addition, miR-365 expression in patients with sepsis following trauma was significantly lower than in patients without sepsis (P<0.05). Similar effects were observed in THP-1 cells treated with LPS. The present study demonstrated that increased expression of IL-6 in patients with sepsis following multiple trauma is associated with decreased expression of miR-365. miR-365 may regulate the occurrence and immune response of sepsis following multiple trauma via IL-6. These results may elucidate agents for clinical diagnosis and treatment of the disease.

Body temperature and mouse scoring systems as surrogate markers of death in cecal ligation and puncture sepsis

Background

Despite increasing ethical standards for conducting animal research, death is still often used as an endpoint in mouse sepsis studies. Recently, the Murine Sepsis Score (MSS), Mouse Clinical Assessment Score for Sepsis (M-CASS), and Mouse Grimace Scale (MGS) were developed as surrogate endpoint scoring systems for assessing pain and disease severity in mice. The objective of our study was to compare the effectiveness of these scoring systems and monitoring of body temperature for predicting disease progression and death in the cecal ligation and puncture (CLP) sepsis model, in order to better inform selection of surrogate endpoints for death in experimental sepsis.

Methods

C57Bl/6J mice were subjected to control sham surgery, or moderate or severe CLP sepsis. All mice were monitored every 4 h for surrogate markers of death using modified versions of the MSS, M-CASS, and MGS scoring systems until 24 h post-operatively, or until endpoint (inability to ambulate) and consequent euthanasia.

Results

Thirty percent of mice subjected to moderate severity CLP reached endpoint by 24 h post-CLP, whereas 100% undergoing severe CLP reached endpoint within 20 h. Modified MSS, M-CASS, and MGS scores all increased, while body temperature decreased, in a time-dependent and sepsis severity-dependent manner, although modified M-CASS scores showed substantial variability. Receiver operating characteristic curves demonstrate that the last recorded body temperature (AUC = 0.88; 95% CI 0.77–0.99), change in body temperature (AUC = 0.89; 95% CI 0.78–0.99), modified M-CASS (AUC = 0.93; 95% CI 0.85–1.00), and modified MSS (AUC = 0.95; 95% CI 0.88–1.01) scores are all robust for predicting death in CLP sepsis, whereas modified MGS (AUC = 0.78; 95% CI 0.63–0.92) is less robust.

Conclusions

The modified MSS and body temperature are effective markers for assessing disease severity and predicting death in the CLP model, and should thus be considered as valid surrogate markers to replace death as an endpoint in mouse CLP sepsis studies.