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 miniLCR␣2 and miniLCR␤ S [PNAS 89:12150, 1992]), mouse ␣-and ␤-globin-knockouts, and 3 different human ␥-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 ␥-transgene that produces intermediate levels of HbF was introduced into knockout sickle mice described by Pàszty and coworkers that express the miniLCR␣1 G

Microvascular blood flow and stasis in transgenic sickle mice: Utility of a dorsal skin fold chamber for intravital microscopy

“…The DSFC model in transgenic sickle mice affords a potential avenue for discovery of the molecular and cellular events leading to stasis and its resolution as well as the testing of potential therapies. The model needs to be tested on other transgenic sickle animals that have varying expression of human g globins in conjunction with the expression of human a and b S globins and varying severity of SCD [48,49]. This model can also be used to examine the role of fluorescently labeled sickle RBCs in the formation of vascular obstructions.…”

Heme degradation and oxidative stress in murine models for hemoglobinopathies: Thalassemia, sickle cell disease and hemoglobin C disease

“…These mice express 100% of all α-globin as human α and 100% of all β-globin as human β S . Group 2 are BERK mice that also express γ M (BERK-γM) as previously described [16]. These mice express 100% human α, 79% human β S , and 21% human γ.…”

“…They express 45% of all α-globins as human α and 73% of all β-globins as human β S . Group 4 animals express the NY1 transgene and the γ M transgene (NY1KO-γM or α H β S γM α KK β KK ) and are homozygous for the mouse α-globin knockout [19] and the mouse β-globin knockout [20] as previously described [16]. These mice express 100% human α, 80% β S , and 20% human γ.…”

“…Transgenic mouse models for pathological hemoglobins are useful experimental tools for testing experimental hypothesis and interventions. Transgenic mice expressing HbS [14][15][16] and HbC [17] were generated by inserting human transgenes that code for human α-and mutant β-chains, and by knocking out murine α-and β-globins. The thalassemia model used here is the result of a homozygous deletion of murine β major [18].…”

Protective effect of arginine on oxidative stress in transgenic sickle mouse models

“…Hemolytic anemia in BERK mice is associated with significantly low systemic hematocrit, i.e., 28.7 ± 4.0 (P<0.00001 vs. controls) [16]. Globin composition was determined by denaturing HPLC as described [9].…”