Jak2-Flox-V617F/Vav1-Cre-Tg

Table 1. Blood routine test results of of HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice(8 weeks）(Data are presented as mean and ± SEM).

Table 2. Blood routine test results of of HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice(10 weeks）(Data are presented as mean and ± SEM).

Table 3. Blood routine test results of of HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice(14 weeks）(Data are presented as mean and ± SEM).

Table 4. Blood routine test results of of HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice (16 weeks）(Data are presented as mean and ± SEM).

Fig1. The observed natural mortality rate of mice within 150 days of birth was less than 10%, though actual values may fluctuate due to incomplete records.

Fig 2. Blood routine test results of HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice.

Fig 3. Alopecia phenotype observed in HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice.

Fig 4. Photographs (A) and Spleen weight (B) of spleen of 27-28 weeks old C57BL/6 and HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice.

Fig 5. Representative images of H&E staining of bone marrow, spleen, and liver in 28-week-old HE/HE Jak2-Flox-V617F/Vav1-Cre-Tgmice. 

Spleen structure is destroyed and significantly enlarged, with a marked reduction in white pulp cells, a substantial increase in erythroid precursor cells, and a notable increase in megakaryocytes. In the bone marrow, there is megakaryocyte hyperplasia and an increase in cell clusters. In liver tissue, megakaryocytes are frequently observed, indicating extramedullary hematopoiesis(n=3).

Fig.6 Reticulin staining of the bone marrow sections from HE/HE Jak2-Flox-V617F&Vav1-Cre-Tg mice (n=3-4, female, 11 weeks old). 

In vivo efficacy assessment

Fig1. The body weight (A) and survival curve (B) of HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg and WT C57BL/6 mice treated with vehicle and Ruxolitinib (n=4–8). 

Fig2. Representative indicators of routine blood in Jak2-Flox-V617F/Vav1-Cre-Tg and WT C57BL/6 mice treated with vehicle and Ruxolitinib (n=4–8). 

^*P<0.05, ^**P<0.01, ^***P<0.001 in control group treatment with G1 versus G2, ^#P<0.05, ^##P<0.01, ^###P<0.001 in control group treatment with G2 versus G3. 

Abbr: WT, wild type; HE, Heterozygous; WBC, white blood cell; RBC, red blood cell; NEUT, Neutrophil count; LYMPH, lymphocyte; PLT, platelet; Monocyte; EO, Eosinophil; BASO, Basophil; Hemoglobin.

Fig3. Flow cytometric analysis of TER-119+, TER-119+Mcd71+, CD42+, and mCD11b+Gr-1+ in blood in HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg and WT C57BL/6 mice at 23 days and 36 days after treatment with vehicle and Ruxolitinib (n=4–8). ^*P<0.05, ^**P<0.01, ^***P<0.001.

Abbr: WT, wild type; HE, Heterozygous; TER-119+, Red blood cell-specific Marker; CD42+,Platelet marker；Gr-1+CD11b+, Granulocyte marker.

Fig4. Spleen size/weight in HE/HE Jak2-Flox-V617F&Vav1-Cre-Tg and WT C57BL/6 mice treated with vehicle and Ruxolitinib (n=4–8).  ^*P<0.05, ^**P<0.01, ^***P<0.001.

Abbr；WT, wild type; HE, Heterozygous.

Fig.5 In vivo efficacy assessment of Ruxolitinib in HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice. H&E staining of spleen from Jak2-Flox-V617F/Vav1-Cre-Tg mice treated with vehicle and Ruxolitinib. Administration of Ruxolitinib (60 mg/kg) to the treatment group was performed at a frequency of twice daily for 36 consecutive days (n=7 females and 1 males, 11 weeks old). Mean ± SEM, Unpaired t-test, *P<0.05.

H&E staining results showed that Ruxolitinib treatment markedly alleviated splenic damage in HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice. However, the difference did not reach statistical significance, likely due to large within-group variation.

Fig.6 In vivo efficacy assessment of Ruxolitinib in HE/HE Jak2-Flox-V617F/Vav1-Cre-Tg mice. Reticulin staining of the bone marrow sections from Jak2-Flox-V617F/Vav1-Cre-Tg mice treated with vehicle and Ruxolitinib. Administration of Ruxolitinib (60 mg/kg) to the treatment group was performed at a frequency of twice daily for 36 consecutive days (n=3-4, female, 11 weeks old). Reticulin staining of bone marrow revealed an elevated level of myelofibrosis in Jak2-Flox-V617F/Vav1-Cre-Tg mice compared to WT C57BL/6 mice. Ruxolitinib reduces myelofibrosis.