title: GATA1-Cre mediates Piga gene inactivation in the erythroid/megakaryocytic lineage and leads to circulating red cells with a partial deficiency in glycosyl phosphatidylinositol-linked proteins (paroxysmal nocturnal hemoglobinuria type II cells).
abstract: Patients with paroxysmal nocturnal hemoglobinuria (PNH) have blood cells deficient in glycosyl phosphatidylinositol (GPI)-linked proteins owing to a somatic mutation in the X-linked PIGA gene. To target Piga recombination to the erythroid/megakaryocytic lineage in mice, the Cre/loxP system was used, and Cre was expressed under the transcriptional regulatory sequences of GATA-1. Breeding of GATA1-cre (G) transgenic mice with mice carrying a floxed Piga (L) allele was associated with high embryonic lethality. However, double-transgenic (GL) mice that escaped early recombination looked healthy and were observed for 16 months. Flow cytometric analysis of peripheral blood cells showed that GL mice had up to 100% of red cells deficient in GPI-linked proteins. The loss of GPI-linked proteins on the cell surface occurred late in erythroid differentiation, causing a proportion of red cells to express low residual levels of GPI-linked proteins. Red cells with residual expression of GPI-linked proteins showed an intermediate sensitivity toward complement and thus resemble PNH type II cells in patients with PNH. Recombination of the floxed Piga allele was also detected in cultured megakaryocytes, mast cells, and eosinophils, but not in neutrophils, lymphocytes, or nonhematopoietic tissues. In summary, GATA1-Cre causes high-efficiency Piga gene inactivation in a GATA-1-specific pattern. For the first time, mice were generated that have almost 100% of red cells deficient in GPI-linked proteins. These animals will be valuable to further investigate the consequences of GPI-anchor deficiency on erythroid/megakaryocytic cells.
authors.affiliation: Division of Hematology, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: M
authors.initials: M
authors.lastname: Jasinski
authors.forename: P
authors.initials: P
authors.lastname: Keller
authors.forename: Y
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: S H
authors.initials: SH
authors.lastname: Orkin
authors.forename: M
authors.initials: M
authors.lastname: Bessler
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism; D019070:Cell Lineage; D004268:DNA-Binding Proteins / Q000494:pharmacology* / Q000502:physiology; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D004920:Erythropoiesis / Q000187:drug effects*; D050982:GATA1 Transcription Factor; D020868:Gene Silencing / Q000187:drug effects*; D017261:Glycosylphosphatidylinositols / Q000172:deficiency*; D006457:Hemoglobinuria, Paroxysmal / Q000473:pathology; D019426:Integrases / Q000494:pharmacology* / Q000502:physiology; D008099:Liver / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D008407:Mast Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008533:Megakaryocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D011995:Recombination, Genetic; D014157:Transcription Factors / Q000494:pharmacology* / Q000502:physiology; D014764:Viral Proteins / Q000494:pharmacology* / Q000502:physiology
chemical_list: D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494689:Gata1 protein, mouse; D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; D014157:Transcription Factors; D014764:Viral Proteins; C080086:phosphatidylinositol glycan-class A protein; C045073:Cre recombinase; D019426:Integrases