|ZFIN ID: ZDB-PUB-090929-3|
A novel zebrafish jak2a(V581F) model shared features of human JAK2(V617F) polycythemia vera
Ma, A.C., Fan, A., Ward, A.C., Liongue, C., Lewis, R.S., Cheng, S.H., Chan, P.K., Yip, S.F., Liang, R., and Leung, A.Y.
|Source:||Experimental hematology 37(12): 1379-1386 (Journal)|
|Registered Authors:||Leung, Anskar, Liongue, Clifford, Ward, Alister C.|
|Keywords:||Zebrafish, hematopoiesis, polycythemia vera, Janus kinase 2|
|PubMed:||19772888 Full text @ Exp. Hematol.|
Ma, A.C., Fan, A., Ward, A.C., Liongue, C., Lewis, R.S., Cheng, S.H., Chan, P.K., Yip, S.F., Liang, R., and Leung, A.Y. (2009) A novel zebrafish jak2a(V581F) model shared features of human JAK2(V617F) polycythemia vera. Experimental hematology. 37(12):1379-1386.
ABSTRACTOBJECTIVE: The Janus kinase 2 (JAK2) is important for embryonic primitive hematopoiesis. A gain-of-function JAK2 (JAK2(V617F)) mutation in human is pathogenetically linked to polycythemia vera (PV). In this study, we generated a zebrafish orthologue of human JAK2(V617F) (referred herewith jak2a(V581F)) by site-directed mutagenesis and examined its relevance as a model of human PV. METHODS: Zebrafish embryos at 1-cell stage were injected with jak2a(V581F) mRNA (200pg/embryos). In some experiments, the embryos were treated with a specific JAK2 inhibitor TG101209. The effects of jak2a stimulation on hematopoiesis, jak/stat signaling and erythropoietin signaling were evaluated at 18hours-post-fertilization (hpf). RESULTS: Injection with jak2a(V581F) mRNA significantly increased erythropoiesis, as enumerated by flow cytometry based on gata1(+) population in dissociated Tg(gata1:gfp) embryos. The response was reduced by stat5.1 morpholino co-injection (Control: 4.37+/-0.08%; jak2a(V581F) injected: 5.71+/-0.07%, Co-injecting jak2a(V581F) and stat5.1 morpholino: 4.66+/-0.13%, p<0.01). jak2a(V581F) mRNA also up-regulated gata1 (1.83+/-0.08 fold, p=0.005), embryonic alpha (alphaeHb: 1.61+/-0.12 fold, p=0.049) and beta-hemoglobin gene expression (betaeHb: 1.65+/-0.13 fold, p=0.026) and increased stat5 phosphorylation. These responses were also ameliorated by stat5.1 morpholino co-injection or treatment with a specific JAK2 inhibitor TG101209. jak2a(V581F) mRNA significantly reduced erythropoietin gene [0.24+/-0.03 fold (p=0.006)] and protein expression (control: 0.633+/-0.11; jak2a(V581F) mRNA: 0.222+/-0.07 mIU/mL, p=0.019). CONCLUSION: The zebrafish jak2a(V581F) model shared many features with human PV and might provide us with mechanistic insights of this disease.