USP10 adenovirus

The ubiquitin-specific peptidase 10 (USP10) protein is a deubiquitinating enzyme involved in many important biological processes. However, the role of USP10 in hepatic ischaemic/reperfusion (I/R) injury is still unclear. Here, researchers show that USP10 is significantly downregulated in mouse liver after hepatic I/R injury and in hepatocytes under hypoxia/reoxygenation stimulation. USP10 heterozygous mice have aggravated hepatic I/R injury, as manifested by aggravated hepatic inflammation and increased hepatocyte apoptosis via the NF-κB signaling pathway. Furthermore, USP10 overexpression inhibits hepatocyte inflammation and apoptosis in hepatic I/R injury both in vivo and in vitro. Mechanistically, USP10 knockdown adversely affects hepatic I/R injury by inducing activation of the transforming growth factor β-activated kinase 1 (TAK1)-JNK/p38 signaling pathway. TAK1 is required for the role of USP10 in hepatic I/R injury, as inhibition of TAK1 in vitro abolishes the function of USP10. In conclusion, these studies suggest that USP10 plays a protective role in liver I/R injury by inhibiting the activation of the TAK1-JNK/p38 signaling pathway. Modulating USP10/TAK1 may be an effective strategy to prevent this pathological process.

To further verify the mechanism of USP10 in hepatic I/R injury, a USP10 overexpression adenoviral vector was constructed and injected into mice to upregulate the expression of USP10 in liver tissue. The results showed that USP10 overexpression significantly reduced serum ALT and AST levels 6 hours after I/R stimulation and reduced the area of liver tissue necrosis (Figure 1A, B). The inflammatory response and apoptosis of AdUSP10 mice were then detected by the same method. The secretion of inflammatory cytokines (TNF-α, IL6, IL1β and Ccl2) and the infiltration of neutrophils (CD11b positive cells) were significantly inhibited (Figure 1C and D). Compared with AdGFP mice, USP10 overexpression significantly inhibited the classic proinflammatory NF-κB signaling pathway (Figure 1E). TUNEL assay results showed that USP10 overexpression could reduce the number of TUNEL positive cells after hepatic I/R injury (Figure 1F). The results of cell apoptosis assay showed that USP10 overexpression could reduce Bad and Bax mRNA expression and upregulate Bcl-2 mRNA expression (Figure 1G). Western blot results verified that Bax and C-caspase 3 protein expression was downregulated and Bcl-2 expression was upregulated (Figure 1H). The results showed that USP10 overexpression alleviated hepatic I/R injury by inhibiting inflammation and cell apoptosis.

Figure 1. USP10 overexpression relieves hepatic injury by inhibiting inflammation and apoptosis in mice I/R model. (Jiangqiao Z, et al., 2020)