Knockdown of TRIM27 alleviated sepsis-induced inflammation, apoptosis, and oxidative stress via suppressing ubiquitination of PPARγ and reducing NOX4 expression

Abstract

Background: Sepsis is a global fatal disease and leads to severe lung injury due to dysfunction of inflammation response. TRIM27 is closely related to the diseased with dysfunction of inflammation response. The aim of this study was to clarify the role and mechanism of TRIM27 in sepsis-induced lung injury.

Methods: The lipopolysaccharide (LPS)-induced septic mouse model was successfully established. The lung injury was evaluated by lung wet/dry (W/D) ratio and hematoxylin-eosin (H&E) staining. The cell apoptosis was evaluated by TUNEL assay. The inflammatory cytokines were measured by quantitative real time-PCR (qRT-PCR) assay and commercial enzyme-linked immunosorbent assay (ELISA). The oxidative stress was assessed by the contents of superoxide dismutase (SOD) and malondialdehyde (MDA), and the expression of dihydroethidium (DHE).

Results: In this study, we demonstrated that TRIM27 was up-regulated in LPS-induced septic mice. In loss-of-function experiments, knockdown of TRIM27 alleviated sepsis-induced lung injury, inflammation, apoptosis, and oxidative stress. More importantly, knockdown of TRIM27 was observed to reduce p-p65/NOX4 expression via suppressing ubiquitination of PPARγ. In rescue experiments, overexpression of NOX4 abolished the effect of sh-TRIM27 on alleviating sepsis-induced inflammation, apoptosis, and oxidative stress.

Conclusion: These findings highlighted that knockdown of TRIM27 alleviated sepsis-induced inflammation, oxidative stress and apoptosis via suppressing ubiquitination of PPARγ and reducing NOX4 expression, which supports the potential utility of TRIM27 as a therapeutic target in septic lung injury.

Keywords: Apoptosis; Inflammation; Lung injury; Oxidative stress; Sepsis; TRIM27.