Role of deubiquitinase OTUD1 in acute lung injury in septic mice: relationship with TAK1-MAPK signaling pathway / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of deubiquitinase OTUD1 in acute lung injury in septic mice and the relationship with transforming growth factor-beta activated kinase 1(TAK1)-mitogen-activated protein kinase (MAPK) signaling pathway.Methods:Twenty male wild-type (WT) and 20 OTUD1 gene knockout (KO) C57BL/6N mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=10 each) using a random number table method: wild-type+ sham operation group (WT-Sham group), wild-type+ sepsis group (WT-SEP group), OTUD1-KO+ sham operation group (KO-Sham group) and OTUD1-KO+ SEP group (KO-SEP group). The acute lung injury was induced by cecal ligation and perforation (CLP) in anesthetized septic mice. Mice were sacrificed at 24 h after operation, blood samples were collected from the abdominal aorta, and lung tissues were collected. Blood gas analysis was performed using the i-STAT blood gas analyzer, PaO 2 and FiO 2 were recorded, and the oxygenation index (OI) was calculated. The morphology of lung tissues was examined with a light microscope for evaluation of lung injury, and lung injury scores were calculated. The wet to dry lung weight (W/D) ratio was measured, and the activities of MPO were measured. The concentrations of TNF-α and IL-6 in plasma were detected by enzyme-linked immunosorbent assay, and the expression of OTUD1, phosphorylated TAK1 (p-TAK1), phosphorylated p38 (p-p38), phosphorylated c-Jun amino-terminal kinase (p-JNK) and phosphorylated extracellular signal-regulated kinase (p-ERK) was detected using Western blot. Results:Compared with WT-Sham group, the PaO 2 and OI were significantly decreased, the lung injury score, W/D ratio, MPO activity, and plasma TNF-α and IL-6 concentrations were increased, and the expression of OTUD1, p-TAK1, p-p38, p-JNK and p-ERK protein in lung tissues was up-regulated in WT-SEP group ( P<0.05). Compared with WT-SEP group, the PaO 2 and OI were significantly decreased, the lung injury score, W/D ratio, MPO activity, and plasma TNF-α and IL-6 concentrations were increased, and the expression of OTUD1, p-TAK1, p-p38, p-JNK and p-ERK protein in lung tissues was up-regulated in KO-SEP group ( P<0.05). Conclusions:OTUD1 is involved in the endogenous protective mechanism against acute lung injury in septic mice, which may be related to the inhibition of TAK1-MAPK signaling pathway activation and decreased inflammatory responses.