Background
Sepsis-associated encephalopathy (SAE) often
Conclusions
Fli-1 in pericytes may serve as a crucial mediator of neuroinflammation during sepsis by directly regulating pivotal cytokines such as MCP-1 and IL-6. Therefore, Fli-1 has the potential to serve as a therapeutic target in SAE and other neuroinflammatory disorders.
Methods
WT and pericyte-specific Fli-1 knockout mice were subjected to endotoxemia through LPS injection or sepsis via cecal ligation and puncture (CLP). In vitro, Fli-1 was knocked down using small interfering RNA in cultured mouse brain pericytes, followed by LPS stimulation.
Results
Elevated Fli-1 levels were observed in isolated brain pericytes 2 h after LPS administration, in brain tissues 4 h after CLP, and in cultured mouse brain pericytes 2 h after LPS stimulation in vitro. In endotoxemic mice, pericyte-specific Fli-1 knockout reduced expression of MCP-1 and IL-6 in brain tissue 2 h after LPS injection. At 24 h post-LPS administration, protein levels of MCP-1 and IL-6, and microglia activation were suppressed in pericyte-Fli-1 knockout mice. Additionally, Fli-1 deficiency in pericytes significantly reduced MCP-1 and IL-6 mRNA levels in the brain tissue 4 h after CLP. Moreover, in cultured brain pericytes, Fli-1 knockdown markedly decreased MCP-1 and IL-6 levels after LPS stimulation. Notably, LPS stimulation increased Fli-1 levels via TLR4-Myd88 signaling, which subsequently led to elevated production of MCP-1 in brain pericytes. Conclusions: Fli-1 in pericytes may serve as a crucial mediator of neuroinflammation during sepsis by directly regulating pivotal cytokines such as MCP-1 and IL-6. Therefore, Fli-1 has the potential to serve as a therapeutic target in SAE and other neuroinflammatory disorders.