Inhibition of JAK1 mitigates postoperative ileus in mice

Intestinal inflammation is the predominant contributor to the genesis of postoperative ileus. Janus kinase 1 plays an important role during inflammation. Here, we investigated the role of Janus kinase 1 in postoperative ileus and whether inhibition of Janus kinase 1 could mitigate postoperative ileus.

A mouse model of postoperative ileus was induced by intestinal manipulation. Janus kinase 1 inhibitor GLPG0634 or placebo was administered orally before intestinal manipulation. At the indicated time points post operation, neutrophil infiltration was assessed by immunohistochemistry and enzyme-linked immunosorbent assay; proinflammatory gene expression was quantified by quantitative reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay; and Janus kinase 1 activation was detected by Western blot. Functional studies were conducted to evaluate intestinal motility.

We found that intestinal manipulation led to marked activation of Janus kinase 1, with increased proinflammatory gene expression and upregulated myeloperoxidase level. Moreover, intestinal manipulation resulted in an impairment of intestinal transit in vivo and inhibition of smooth muscle contractility in vitro. Preoperative administration of GLPG0634 markedly lowered the expression of proinflammatory cytokines, the myeloperoxidase level in the muscularis layer after bowel manipulation, and significantly ameliorated smooth muscle contractile function and intestinal transit ability.

Our data showed that Janus kinase 1 activation mediated intestinal manipulation-induced resident macrophage activation after intestinal manipulation, and subsequent complex inflammatory cascade and gut dysmotility. Janus kinase 1 inhibition appears to be a prospective and convenient approach for the prevention of postoperative ileus.