Ruxolitinib may treat aplastic anaemia by reducing levels of macrophage pyroptosis

Abstract Abstract Background: Severe Aplastic anaemia (SAA) is a disorder of bone marrow haematopoiesis caused by a variety of aetiological factors. The JAK-STAT pathway has been shown to be involved in the control of inflammatory cytokines and immune activation, and ruxolitinib, a JAK1/2 inhibitor, can effectively inhibit T-cell activation and the associated inflammatory response, and has been confirmed in animal studies to be able to improve the disease status of AA mice. Our previous studies have shown that the level of pyroptosis is significantly increased in SAA patients compared to normal subjects, and macrophage pyroptosis is also considered to be an important factor involved in the immune activation of the organism. Aims: This study aimed to investigate whether ruxolitinib can treat SAA by affecting macrophage pyroptosis and to explore the mechanism. Methods: A human mononuclear THP-1 cell line was first induced to differentiate into macrophages in vitro and to undergo pyroptosis. The macrophages were then treated with different concentrations of ruxolitinib to determine the levels of pyroptosis and inflammatory factors. RNA transcriptome sequencing and molecular mimicry docking were then used to find the relevant pathways. Finally, validation was performed in the SAA mouse model. Results: We found that pyroptosis factor were gradually reduced with the increase of ruxolitinib concentration; further studies found that some inflammation-related factors also showed a very clear trend of reduction with the increase of ruxolitinib concentration. When different concentrations of ruxolitinib were added and cells were labelled with CD80, CD86 and HLA-DR, it was found by flow cytometry that the addition of ruxolitinib was able to activate MHC class II molecules to a certain extent by flow cytometry, which may initiate the paracrine activation of CD4+ T cells. This suggests that ruxolitinib may be able to improve the immune environment in AA. After that, we used RNA transcriptome sequencing and molecular simulation docking to find the signalling pathway. The results suggest that ruxolitinib can act by inhibiting the JAK/STAT pathway and potentially have an effect on autophagy. Finally, the SAA mouse model suggests that ruxolitinib can inhibit pyroptosis via macrophages to some extent, but cannot restore it to normal levels. Conclusion: The results of our experiments showed that ruxolitinib can treat SAA by reducing the level of macrophage pyroptosis, thereby treating SAA. Although our results still need to be validated with clinical data and more detailed experiments, but we hope that our findings will provide new ideas for the treatment of SAA. Keywords: Aplastic anemia, Macrophages, Pyroptosis, Ruxolitinib