Abstract
BACKGROUND: Pericytes are vascular mural cells and are embedded in the basement membrane of the microvasculature. Recent studies suggest a role for pericytes in lipopolysaccharide (LPS)-induced microvascular dysfunction and mortality, but the mechanisms of pericyte loss in sepsis are largely unknown. METHODS: By using a cecal ligation and puncture (CLP)-induced murine model of sepsis, we observed that CLP led to lung and renal pericyte loss and reduced lung pericyte density and pericyte/endothelial cell (EC) coverage. RESULTS: Up-regulated Friend leukemia virus integration 1 (Fli-1) messenger ribonucleic acid (RNA) and protein levels were found in lung pericytes from CLP mice in vivo and in LPS-stimulated lung pericytes in vitro. Knockout of Fli-1 in Foxd1-derived pericytes prevented CLP-induced pericyte loss, vascular leak, and improved survival. Disrupted Fli-1 expression by small interfering RNA inhibited LPS-induced inflammatory cytokines and chemokines in cultured lung pericytes. Furthermore, CLP-induced pericyte pyroptosis was mitigated in pericyte Fli-1 knockout mice. CONCLUSIONS: Our findings suggest that Fli-1 is a potential therapeutic target in sepsis.