[Protective effect of serine methyltransferase against hepatic ischemia-reperfusion injury in mice].

Objective: To investigate the protective effect of serine hydroxymethyl transferase 2 (SHMT2) against hepatic ischemia-reperfusion injury in mice.

Methods: Sixty C57BL/6 mice were divided equally into sham-operated group, saline adeno-associated virus group (AVV-GFP), and adeno-associated virus silencing group (AAV-SHMT2). The adeno-associated virus and normal saline were injected into the tail vein of the mice 2 weeks before establishment of a 70% ischemia-reperfusion model in the liver. qPCR, Western blotting, immunofluorescence and immunohistochemistry were used to detect the changes of AST/ALT concentration, SHMT2, JNK, NF-κB, caspase-3 and downstream inflammatory factors in the mice, and HE staining was used to observe the pathological damage of the liver tissue in each group; the cell apoptosis in the liver was detected using TUNEL assay.

Results: The expression of SHMT2 increased with time after hepatic ischemia-reperfusion and reached the highest level at 24 h (the relative expression was 1.5, < 0.05). At 24 h after hepatic ischemia-reperfusion, the levels of AST/ALT in AAV-SHMT2 group (588/416 U/L) were significantly higher than those in the control group (416/345 U/L) and the empty vector group (387/321 U/L) ( < 0.05). Compared with those in the control group and the empty vector group, the level of SHMT2 was significantly decreased in AAV-SHMT2 group (with a relative expression of 0.24, < 0.05), the levels of p-JNK and p-p65 were significantly increased (relative expression of 0.80 and 0.97, respectively, < 0.05), and the levels TNF-α and IL-1β were consistently elevated (relative expression levels of 1.6 and 1.2, respectively, < 0.05). No significant differences were found in these parameters between the empty vector group and the control group (>0.05).

Conclusions: SHMT2 may alleviate liver cell apoptosis in mice with hepatic ischemia-reperfusion injury by inhibiting the activation of JNK pathway and excessive activation of NF-κB pathway to reduce hepatic damage.