Replenishing HDL with synthetic HDL has multiple protective effects against sepsis in mice

Sepsis is a major health issue with mortality exceeding 30% and few treatment options. We found that high-density lipoprotein cholesterol (HDL-C) abundance was reduced by 45% in septic patients compared to that in nonseptic patients. Furthermore, HDL-C abundance in nonsurviving septic patients was substantially lower than in those patients who survived. We therefore hypothesized that replenishing HDL might be a therapeutic approach for treating sepsis and found that supplementing HDL with synthetic HDL (sHDL) provided protection against sepsis in mice. In mice subjected to cecal ligation and puncture (CLP), infusing the sHDL ETC-642 increased plasma HDL-C amounts and improved the 7-day survival rate. Septic mice treated with sHDL showed improved kidney function and reduced inflammation, as indicated by marked decreases in the plasma concentrations of blood urea nitrogen (BUN) and the cytokines interleukin-6 (IL-6) and IL-10, respectively. We found that sHDL inhibited the ability of the endotoxins LPS and LPA to activate inflammatory pathways in RAW264.7 cells and HEK-Blue cells expressing the receptors TLR4 or TLR2 and NF-kappa B reporters. In addition, sHDL inhibited the activation of HUVECs by LPS, LTA, and TNF-alpha. Together, these data indicate that sHDL treatment protects mice from sepsis in multiple ways and that it might be an effective therapy for patients with sepsis.