Sunitinib alleviates hepatic ischemia reperfusion injury by inhibiting the JAK2/STAT pathway and promoting the M2 polarization of macrophages.

Background: Hepatic ischemia reperfusion injury (IRI) is a common liver surgery complication. This study aims to explore the effect and potential mechanism of Sunitinib - a multi-target tyrosine kinase inhibitor - on hepatic IRI.

Methods: We established a hepatic IRI model using C57BL/6 mice, and integrated 40 mg/kg of Sunitinib, solely or combined with 100 μg/kg of coumermycin A1 (C-A1), in the treatment strategy. H&E staining, TUNEL assay, and detection of serum ALT and AST activities were used to assess liver damage. Further, ELISA kits and Western Blots were utilized to determine IL-1β, TNF-α, IL-6, CXCL10, and CXCL2 levels. Primary macrophages, once isolated, were cultured in vitro with either 2 nM of Sunitinib, or Sunitinib in conjunction with 1 μM of C-A1, to gauge their influence on macrophage polarization. qPCR and Western blot were conducted to examine the level of p-STAT1/STAT1, p-STAT3/STAT3, p-JAK2/JAK2, and M1/M2 polarization markers. To quantify immune cell infiltration, we applied Immunofluorescence.

Results: Sunitinib pretreatment significantly alleviated liver injury and reduced p-STAT1/STAT1, p-STAT3/STAT3, p-JAK2/JAK2 levels. In vitro, Sunitinib treatment curbed M1 polarization induced by LPS + IFN-γ and bolstered M2 polarization triggered by IL-4. C-A1 application upregulated JAK2/STAT pathway phosphorylation and promoted LPS + IFN-γ-induced M1 polarization, which was reversed by Sunitinib treatment. In IL-4-stimulated macrophages, application of C-A1 activated the JAK2/STAT pathway and decreased M2-type macrophages, which was reversed by Sunitinib treatment either.

Conclusion: Sunitinib is capable of guiding the polarization of macrophages toward an M2-type phenotype via the inhibition of the JAK2/STAT pathway, thereby exerting a protective effect on hepatic IRI.