title: Second generation knockout sickle mice: the effect of HbF.
abstract: Sickle transgenic mice expressing exclusively human globins are desirable for studying pathophysiology and testing gene therapy strategies, but they must have significant pathology and show evidence of amelioration by antisickling hemoglobins. Mice were generated that expressed exclusively human sickle hemoglobin with 3 levels of HbF using their previously described sickle constructs (cointegrated human miniLCRalpha2 and miniLCRbeta(S) [PNAS 89:12150, 1992]), mouse alpha- and beta-globin-knockouts, and 3 different human gamma-transgenes. It was found that, at all 3 levels of HbF expression, these mice have balanced chain synthesis, nearly normal mean corpuscular hemoglobin, and, in some cases, F cells. Mice with the least adult HbF expression were the most severe. Progressive increase in HbF from less than 3% to 20% to 40% correlated with progressive increase in hematocrit (22% to 34% to 40%) and progressive decrease in reticulocyte count (from 60% to 30% to 13%). Urine concentrating ability was normalized at high HbF, and tissue damage detected by histopathology and organ weight were ameliorated by increased HbF. The gamma-transgene that produces intermediate levels of HbF was introduced into knockout sickle mice described by Pàszty and coworkers that express the miniLCRalpha1(G)gamma(A)gammadeltabeta(S) transgene and have fetal but not adult expression of HbF. It was found that the level of HbF required to ameliorate low hematocrit and normalize urine concentrating defect was different for the miniLCRalpha2beta(S) and miniLCRalpha1(G)gamma(A)gammadeltabeta(S) mice. We conclude that knockout mice with the miniLCRalpha2beta(S) transgene and postnatal expression of HbF have sufficiently faithful sickle pathology to serve as a platform for testing antisickling interventions.
authors.affiliation: Departments of Medicine and Pathology, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY 10461, USA. fabry@aecom.yu.edu
authors.forename: M E
authors.initials: ME
authors.lastname: Fabry
authors.forename: S M
authors.initials: SM
authors.lastname: Suzuka
authors.forename: R S
authors.initials: RS
authors.lastname: Weinberg
authors.forename: C
authors.initials: C
authors.lastname: Lawrence
authors.forename: S M
authors.initials: SM
authors.lastname: Factor
authors.forename: J G
authors.initials: JG
authors.lastname: Gilman
authors.forename: F
authors.initials: F
authors.lastname: Costantini
authors.forename: R L
authors.initials: RL
authors.lastname: Nagel
mesh_terms: D019794:2,3-Diphosphoglycerate / Q000097:blood; D000367:Age Factors; D000755:Anemia, Sickle Cell / Q000097:blood / Q000378:metabolism / Q000473:pathology; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005319:Fetal Hemoglobin / Q000494:pharmacology; D005914:Globins / Q000096:biosynthesis / Q000187:drug effects; D006400:Hematocrit; D006451:Hemoglobin, Sickle / Q000187:drug effects / Q000235:genetics; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D007671:Kidney Concentrating Ability / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout / Q000235:genetics*; D008822:Mice, Transgenic / Q000235:genetics*; D017701:Reticulocyte Count; D013154:Spleen / Q000187:drug effects / Q000473:pathology; D013789:Thalassemia / Q000097:blood / Q000378:metabolism / Q000473:pathology
chemical_list: D006451:Hemoglobin, Sickle; D019794:2,3-Diphosphoglycerate; D005914:Globins; D005319:Fetal Hemoglobin