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.
Date: 2009
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
MeSH Terms:
  • Amino Acid Sequence
  • Amino Acid Substitution
  • Animals
  • Base Sequence
  • Blotting, Western
  • Disease Models, Animal
  • Embryo, Nonmammalian/enzymology
  • Embryo, Nonmammalian/metabolism
  • Erythropoiesis/genetics
  • Erythropoietin/genetics
  • Erythropoietin/metabolism
  • Gene Expression Regulation, Developmental
  • Humans
  • Janus Kinase 2/antagonists & inhibitors
  • Janus Kinase 2/genetics*
  • Janus Kinase 2/metabolism*
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Mutation*
  • Polycythemia Vera/enzymology
  • Polycythemia Vera/genetics
  • Polycythemia Vera/pathology*
  • Protein-Tyrosine Kinases/antagonists & inhibitors
  • Protein-Tyrosine Kinases/genetics*
  • Protein-Tyrosine Kinases/metabolism
  • Pyrimidines/pharmacology
  • Reverse Transcriptase Polymerase Chain Reaction
  • STAT5 Transcription Factor/genetics
  • STAT5 Transcription Factor/metabolism
  • Sequence Homology, Amino Acid
  • Sulfonamides/pharmacology
  • Zebrafish/embryology
  • Zebrafish/genetics
  • Zebrafish/metabolism
  • Zebrafish Proteins/antagonists & inhibitors
  • Zebrafish Proteins/genetics*
  • Zebrafish Proteins/metabolism
PubMed: 19772888 Full text @ Exp. Hematol.
OBJECTIVE: 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.