AJ Ruggieri1, CS Deutschman2

1Clinical Monitoring, inVentiv Health Clinical, Blue Bell PA

2Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia PA.

Murine model of sepsis, mimicking human sepsis, designed to illuminate the effect of this enigmatic condition on mitochondrial biogenesis in the liver. The most well known model of murine sepsis induction is the cecal ligation and puncture (CLP) model. This, along with sham operation control (SO) and cecal ligation and double puncture (2CLP), was induced in C57Bl/6 mice. It is hypothesized that mitochondrial counts in mice under this septic model will decrease versus control. Sepsis was induced via surgery under anesthesia. Pre-mortem, the mice were injected with MitoTracker® Red CM-H2XRos to allow visualization of active mitochondria in the liver. Hepatic tissue was then harvested, paraffin embedded, and immuno-stained for VDAC-1 (green). Slides were immuno-stained for Myeloperoxidase (MPO) blue, for neutrophil accumulation, in the same time points as before. ANOVA and Tukey-Kramer analysis were performed for all. Survival rates were calculated using Kaplen-Meier analysis. MitoTracker® and VDAC-1 fluorescence, and the MitoTracker®/VDAC-1 ratio were unchanged in 24, 48 and 72 hours after SO and CLP. There was a decrease in all three parameters in 72 hours 2CLP (P=0.0041). Survivability showed a significant decrease in rates between 48 hour and 72 hour time points (P=0.0291). MPO images and data analysis showed that MPO levels were higher at 72 hours under 2CLP when compared to T0. The level of total mitochondria, actively respiring mitochondria, and the ratio between the two, was significantly decreased at 72 hours following 2CLP. These changes are not due to neutrophil influx, as the results show. These findings suggest that 2CLP impairs mitochondrial biogenesis in the liver.