Heart transcriptome of different subtype of sepsis induced myocardium dysfunction according to ejection fraction
Dysregulated cardiac function after sepsis is common in intensive care unit (ICU) and known to predict poor long-term outcome and increase mortality. Effective therapeutic strategies are largely lacking. Moreover, the pathological feature and the molecular mechanism underlying cardiac dysfunction induced by sepsis remain unclear. Here, by performing echocardiograms on rodents after induction of polymicrobial sepsis with cecum ligation and puncture (CLP), we assessed the temporal dynamics of left ventricular ejection fraction (LVEF) and a serial of hemodynamics parameters on animals at different time point after CLP. Intriguingly, the mean LVEF is comparable in mice induced by CLP and sham, whereas survivors post CLP had stable LVEF and non-survivors had markedly fluctuated LVEF at early phase of CLP induction, suggesting LVEF away from normal range is highly associated with mortality. Consistent with clinical observations of depressed, preserved or hyperdynamic LVEF in septic patients from data compiled using our ICU cohort and from other studies, CLP-induced mice fall into three groups based on LVEF measured at 24 hours after surgery: high LVEF (HEF, LVEF>=90%), low LVEF (LEF, LVEF<65%), and normal LVEF (NEF, 65%=<LVEF<90%). We performed genome-wide transcriptomic and proteomic profiling on left ventricle samples collected from three CLP groups and sham mice. By implementing pathway analysis, gene set enrichment and coexpression network analysis, we identified jointly and distinctively changed genes, proteins and biologically-essential processes and pathways in three CLP groups with different LVEF. Notably, transmission electron microscopy examination shows remarkable mitochondrial and sarcomere defects in three CLP groups with different phenotypes associated with LVEF variances. Together, this study systematically characterizes the molecular, morphological, and functional alterations in CLP-induced cardiac injury, serving as a framework for future research into pathology and molecular mechanism of sepsis-induced cardiomyopathy. Overall design: Heart tissue samples for one day after sepsis mice model, including sham group(S,n=4),high LVEF group(HEF, LVEF>=90%)(C1,n=4), low LVEF (LEF, LVEF<65%)(C2,n=3), and normal LVEF (NEF, 65%=<LVEF<90%)(C3,n=4) according to left ventricular ejection fraction