C57BL/6-Tg(Vav1-EIF2AK2)#Wsmay/J

Stock number: 027460
Product name: TgPKR
Research areas: Cancer Research, Cell Biology Research, Developmental Biology Research, Endocrine Deficiency Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

TgPKR mice express wildtype (catalytically-active) human PKR exclusively in hematopoietic cells/tissues under control of the mouse HS21/45-vav regulatory elements. This PKR overexpression results in significantly defective hematopoiesis, bone marrow failure and increased sensitivity to apoptosis-inducing cell stress. These TgPKR mice may be useful in studying increased PKR activity in diseases such as myelodysplastic syndrome (MDS).

Detailed description

Protein kinase R (PKR) is an interferon (IFN)-inducible, double-stranded RNA-activated kinase that initiates apoptosis in response to cellular stress and inhibits DNA damage response signaling. Increased PKR activity is reported in myeloid progenitor cell populations from patients with myelodysplastic syndrome (MDS) and is associated with poor survival for many cancers.

These vav-PKR transgenic mice (TgPKR) have the mouse HS21/45-vav regulatory elements directing expression of wildtype (catalytically-active) human PKR to hematopoietic cells/tissues. High PKR expression is reported in thymus, spleen and bone marrow (BM) compared with non-hematopoietic tissues (small intestine, liver or kidney) as demonstrated by real-time quantitative PCR and western blotting. This PKR overexpression results in significantly defective hematopoiesis, BM failure and increased sensitivity to apoptosis-inducing cell stress.


Specifically, TgPKR mice have increased PKR expression/activation that leads to features of defective hematopoiesis and BM failure, as demonstrated by mild pancytopenia of all peripheral blood elements (significantly lower total white blood cell, neutrophil, lymphocyte, platelet, and hemoglobin counts compared with non-transgenic mice). Hematopoiesis defects are even more pronounced in older mice (16-18 months old). In addition, the BM contains dysplasic-appearing cells, reduced hematopoietic stem/progenitor cell populations (HSPCs), reduced mature myeloid cell populations, reduced hematopoietic colony-forming capacity, and increased sensitivity to apoptosis-inducing cell stress (including inflammatory cytokines, growth factor starvation and irradiation) when compared with cells from non-transgenic mice. TgPKR mice display a mutator phenotype characterized by an increased frequency of radiation-induced or age-associated mutations in peripheral blood cells.

Furthermore, an increased percentage of HSPCs isolated from TgPKR mice are quiescent (G₀) compared with non-transgenic mice.

Hemizygous TgPKR mice are viable and fertile. To date (July 2015), it has not been attempted to make this strain homozygous.

The phenotype of hemizygous TgPKR mice is in contrast to hemizygous mice expressing a catalytically-null/dominant-negative variant of human PKR from the same HS21/45-vav regulatory elements (TgDNPKR; Stock No. 027461). Those TgDNPKR mice exhibit loss of PKR activity in BM cells and increased HSPCs, as well as BM cell-resistance to apoptosis-inducing cell stress.

Development

The vav-PKR transgene was designed by Dr. W. Stratford May Jr (University of Florida) with the mouse vav 1 oncogene promoter/control regions (Vav1; from the HS21/45-vav vector) directing expression of a wildtype (catalytically-active) human eukaryotic translation initiation factor 2-alpha kinase 2 cDNA sequence (EIF2AK2 or protein kinase R [PKR]). Specifically, the transgene has (from 5' to 3') the two proximal upstream Vav1 DNase-I hypersensitive sites (HS21), an SV40 intron, the human PKR cDNA sequence, an SV40 polyA signal and Vav1 intron 1 (containing both proximal HS sites (HS45)). This 8.5 kbp vav-PKR transgene was microinjected into the pronuclei of C57BL/6J eggs, and then founder animals were bred to C57BL/6J mice for germline transmission. Three transgenic (TgPKR) founder lines were generated; all displaying the same phenotype and were used interchangeably (i.e., the reported/published results come from mice of all three founder lines). TgPKR mice were then bred with C57BL/6J wildtype mice for more than seven generations prior to sending males with black coat color to The Jackson Laboratory Repository in 2016. Upon arrival, males were used to cryopreserve sperm. To establish the living TgPKR mouse colony, an aliquot of the frozen sperm was used to fertilize oocytes from C57BL/6J inbred females (Stock No. 000664).

Allele

Symbol: Tg(Vav1-EIF2AK2)#Wsmay
Name: transgene insertion, W May
MGI accession ID: MGI:5646202
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Synonyms: TgPKR
Marker symbol: Tg(Vav1-EIF2AK2)#Wsmay
Marker name: transgene insertion, W May
Chromosome: UN
Strain of origin: C57BL/6
Expressed genes: EIF2AK2,eukaryotic translation initiation factor 2 alpha kinase 2,human
Molecular note: The transgenic construct contains a mouse vav 1 oncogene promoter/control regions directing expression of a wildtype (catalytically-active) human eukaryotic translation initiation factor 2-alpha kinase 2 cDNA sequence (EIF2AK2). Three transgenic (TgPKR) founder lines were generated; all displaying the same phenotype and were used interchangeably.