Recombinant hirudin regulates macrophage polarisation status through PAR-1 in diffuse large B-cell lymphoma

Abstract Background Diffuse large B-cell lymphoma (DLBCL) is a malignant tumour. Although some standard therapies have been established to improve the cure rate, these therapies are still ineffective in some patients. Therefore, it is meaningful to look for more novel therapeutic approaches. Macrophage polarisation is extensively involved in the process of tumour development. Recombinant hirudin (rH) affects macrophages and has been researched frequently in clinical trials lately. Our article validates the regulatory role of rH in macrophage polarisation and the regulatory pathways by collecting clinical samples and subsequently establishing a cellular model to provide a scientifically supported viewpoint for discovering new therapeutic approaches. Method Initially, we assessed the expression of macrophage polarisation markers, inflammatory factors and PAR-1 in clinical samples. Then, we established a cell model by co-culture and determined the degree of cell polarisation and expression of validation factors by flow cytometry, ELISA, and RT-qPCR to confirm the success of the cell model. Subsequently, different doses of rH were added to discover the function of rH on cell polarisation. Finally, we confirmed the mechanism of rH in macrophage polarisation by transfecting si-PAR-1 and pcDNA3.1-PAR-1. Results We found higher expression of M2 macrophage markers (CD163 + CMAF+) and PAR-1 in 30 DLBCL samples. After inducing monocyte differentiation into M0 macrophages and co-culturing with OCI-Ly10 lymphoma cells, we found a trend of these expressions in the cell model consistent with the clinical samples. Subsequently, we discovered that rH promotes the polarisation of M1 macrophages but inhibits the polarisation of M2 macrophages. Later, we also found that rH regulates macrophage polarisation through PAR-1, inhibiting cell proliferation, migration, invasion and angiogenic capacity. Conclusion rH inhibits macrophage polarisation towards the M2 type and regulates polarisation, proliferation, migration, invasion, and angiogenesis of DLBCL-associated macrophages through PAR-1.