Towards a transgenic mouse model of sickle cell disease: hemoglobin SAD.
In order to obtain a transgenic mouse model of sickle cell disease, we have synthesized a novel human beta-globin gene, beta SAD, designed to increase the polymerization of the transgenic human hemoglobin S (Hb S) in vivo. beta SAD (beta S-Antilles-D Punjab) includes the beta 6Val substitution of the beta S chain, as well as two other mutations, Antilles (beta 23Ile) and D Punjab (beta 121Gln) each of which promotes the polymerization of Hb S in human. The beta SAD gene and the human alpha 2-globin gene, each linked to the beta-globin locus control region (LCR) were co-introduced into the mouse germ line. In one of the five transgenic lines obtained, SAD-1, red blood cells contained 19% human Hb SAD (alpha 2 human 1 beta 2SAD) and mouse-human hybrids in addition to mouse hemoglobin. Adult SAD-1 transgenic mice were not anemic but had some abnormal features of erythrocytes and slightly enlarged spleens. Their erythrocytes displayed sickling upon deoxygenation in vitro. SAD-1 neonates were anemic and many did not survive. In order to generate adult mice with a more severe sickle cell syndrome, crosses between the SAD progeny and homozygous for beta-thalassemic mice were performed. Hemoglobin SAD was increased to 26% in beta-thal/SAD-1 mice which exhibited: (i) abnormal erythrocytes with regard to shape and density; (ii) an enlarged spleen and a high reticulocyte count indicating an increased erythropoiesis; (iii) mortality upon hypoxia; (iv) polymerization of hemolysate similar to that obtained in human homozygous sickle cell disease; and (v) anemia and mortality during development.
Trudel
M
M
Department of Genetics and Development, Columbia University, New York, NY 10032.
Saadane
N
N
Garel
M C
MC
Bardakdjian-Michau
J
J
Blouquit
Y
Y
Guerquin-Kern
J L
JL
Rouyer-Fessard
P
P
Vidaud
D
D
Pachnis
A
A
Roméo
P H
PH
D000755:Anemia, Sickle Cell / Q000401:mortality / Q000503:physiopathology*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000235:genetics; D004195:Disease Models, Animal; D004591:Electrophoresis, Polyacrylamide Gel; D004909:Erythrocyte Indices; D005914:Globins / Q000235:genetics; D006451:Hemoglobin, Sickle / Q000235:genetics / Q000378:metabolism*; D007525:Isoelectric Focusing; D051379:Mice; D008822:Mice, Transgenic; D010100:Oxygen / Q000378:metabolism; D010449:Peptide Mapping; D010641:Phenotype; D016133:Polymerase Chain Reaction; D014357:Trypsin
D006451:Hemoglobin, Sickle; C070168:hemoglobin SAD; D005914:Globins; D004247:DNA; D014357:Trypsin; D010100:Oxygen