MicroRNA-181a-5p Regulates Inflammatory Response of Macrophages in Sepsis

Area of Science:

• Molecular Biology
• Immunology
• Pathophysiology

Background:

• Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection.
• MicroRNAs (miRNAs) play crucial roles in regulating inflammatory responses.
• The specific role of miR-181a-5p in sepsis pathogenesis remains unclear.

Purpose of the Study:

• To investigate the role of miR-181a-5p in sepsis.
• To elucidate the molecular mechanism underlying miR-181a-5p's function in sepsis.
• To explore miR-181a-5p as a potential therapeutic target for sepsis.

Main Methods:

• RAW 264.7 macrophages were stimulated with lipopolysaccharide (LPS).
• Quantitative real-time PCR (qRT-PCR) and ELISA were used to measure gene and protein expression.
• In vivo sepsis models in mice were established to evaluate therapeutic effects.

Main Results:

• LPS stimulation significantly increased miR-181a-5p and pro-inflammatory cytokine expression in macrophages.
• Sirtuin-1 (SIRT1) was identified as a direct target of miR-181a-5p and was downregulated in LPS-treated cells.
• Inhibiting miR-181a-5p reduced inflammatory cytokine production and NF-κB pathway activation, effects reversed by SIRT1 silencing.
• In vivo, miR-181a-5p inhibition decreased inflammatory factors and organ damage markers in septic mice, with effects reversed by SIRT1-siRNA.

Conclusions:

• miR-181a-5p promotes sepsis-induced inflammation by targeting SIRT1.
• Modulating miR-181a-5p activity, particularly through inhibition, offers a potential therapeutic strategy for sepsis.
• Targeting the miR-181a-5p/SIRT1 axis may be beneficial in managing sepsis.