cangrelor and Pulmonary-Fibrosis

Pulmonary fibrosis is a progressive chronic inflammatory lung disease whose pathogenesis is complicated. Platelets and neutrophils play important roles in the progression of pulmonary inflammation. We have reported that cangrelor, a non-sepesific GPR17 antagonist, alleviates pulmonary fibrosis partly by inhibiting macrophage inflammation in mice. Cangrelor is also a well-known anti-platelet agent. To test whether cangrelor mitigated pulmonary fibrosis partly through the inhibition of platelets, bleomycin (BLM) was used to induce pulmonary fibrosis in C57BL/6 J mice. We found that cangrelor (10 mg/kg) not only significantly decreased BLM-induced release of inflammatory cytokines (PF4, CD40 L and MPO), but also decreased the increment of platelets, neutrophils and platelet-neutrophil aggregates in the fibrotic lung and in the peripheral blood of BLM-treated mice. In addition, cangrelor decreased the number of CD40 and MPO double positive neutrophils and the expression level of CD40 in BLM-treated mouse lungs. Based on these results we conclude that cangrelor alleviates BLM-induced lung inflammation and pulmonary fibrosis in mice, partly through inhibition of platelet activation, therefore reducing the infiltration of neutrophils due to the adhesion of platelets and neutrophils mediated by CD40 - CD40 L interaction. Cangrelor could be a potential therapeutic medicine for pulmonary fibrosis.

Topics: Adenosine Monophosphate; Animals; Bleomycin; CD40 Antigens; Cytokines; Disease Models, Animal; Inflammation Mediators; Lung; Male; Mice; Mice, Inbred C57BL; Neutrophil Infiltration; Neutrophils; Platelet Activation; Platelet Aggregation Inhibitors; Pulmonary Fibrosis

Pulmonary fibrosis is a progressive and intractable lung disease. Macrophages play a critical role in the progression of pulmonary fibrosis. Cangrelor, an anti-platelet agent, is also a non-selective Gprotein-coupled receptor 17 (GPR17) antagonist. GPR17 mediates microglial inflammation in the chronic phase of cerebral ischemia and regulates allergic pulmonary inflammation. In this study, we observed the effects of cangrelor on bleomycin (BLM)-induced macrophage cellular inflammation and BLM-induced pulmonary fibrosis in C57BL/6J mice. We found that BLM significantly increased GPR17 expression, the mRNA synthesis and release of inflammatory cytokines including TNF-α, IL-6 and TGF-β1 in murine RAW 264.7 macrophage cells. Knockdown of GPR17 attenuated the BLM-induced inflammatory responses. Cangrelor (2.5 μM-10 μM) significantly alleviated BLM-induced inflammatory response in RAW 264.7 macrophage cells in concentration-dependent manner. In BLM-induced fibrotic mouse lungs, GPR17 expression and GPR17-positive macrophages were increased. Cangrelor (2.5 mg/kg-10 mg/kg) alleviated pulmonary fibrosis in dose-dependent manner. Cangrelor not only reduced the number of GPR17-positive macrophages, but also decreased BLM-induced mRNA synthesis and release of inflammatory cytokine. As such, we concluded that cangrelor alleviates BLM-induced pulmonary fibrosis by suppressing GPR17-mediated inflammation. Cangrelor could be a potential therapeutic drug for pulmonary fibrosis.

Topics: Adenosine Monophosphate; Animals; Bleomycin; Cell Survival; Dose-Response Relationship, Drug; Inflammation; Interleukin-6; Male; Mice; Mice, Inbred C57BL; Nerve Tissue Proteins; Pulmonary Fibrosis; RAW 264.7 Cells; Receptors, G-Protein-Coupled; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha