Toxicicty of ruxolitinib in normal mice

Background and methods: Ruxolitinib (RUX), a Jak1/2 inhibitor, has been reported to attenuate murine bone marrow failure recently. Its potential toxocicty of anemia and thrombocytopenia in human remains a concern. We tested the toxicity of ruxolitinib on hematopoiesis in normal mice by feeding the mice with RUX chow for 3 months. Bone marrow Lin-CD117+ cells were sorted from treated or untreated mice. RNA-Seq and analysis was performed using SMART-Seq mRNA LP Kit (Takara) and the Illumina Novaseq6000, according to the Institute's protocols. Results: Ruxolitinib reduced RBC and lymphocytes, but did not affect NEU and PLT in normal mice. RNA sequencing demonstrated that HSPCs from RUX-treated and untreated mice had overlapped transcriptome distribution in multiple dimentional scalling plot, indicating overall similarity at molecular level. Conclusion: Our results demonstrate that ruxolitinib has minimal toxicity on hematopoiesis in normal mice. We compared transcriptomes of HSPCs from the mice treated with and without ruxolitinib, and described differentially expressed genes of these cells. Lin-CD117+ cells were FACS-sorted from bone marrow of ruxolitinib-treated and untreated mice. To get enough cells for RNA extraction, Lin-CD117+ cells from every 2-3 mice in the same group were pooled together, we obtained 3 pools/group.