In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 109, No. 2 ( 2012-01-10), p. 576-581
Kurzfassung:
Diverse mutations in the genes encoding hemoglobin (Hb) have been characterized in human disease. We describe here a mutation in the mouse Hbb-b2 gene, denoted Plt12 , that precisely mimics the human hemoglobin Hotel Dieu variant. The mutation results in increased affinity of Hb for oxygen and Plt12 mutant mice exhibited reduced partial pressure of O 2 in the blood, accompanied by erythrocytosis characterized by elevated erythropoietin levels and splenomegaly with excess erythropoiesis. Most homozygous Hbb-b2 Plt12/Plt12 mice succumbed to early lethality associated with emphysema, cardiac abnormalities, and liver degeneration. Survivors displayed a marked thrombocytopenia without significant deficiencies in the numbers of megakaryocytes or megakaryocyte progenitor cells. The lifespan of platelets in the circulation of Hbb-b2 Plt12/Plt12 mice was normal, and splenectomy did not correct the thrombocytopenia, suggesting that increased sequestration was unlikely to be a major contributor. These data, together with the observation that megakaryocytes in Hbb-b2 Plt12/Plt12 mice appeared smaller and deficient in cytoplasm, support a model in which hypoxia causes thrombocytopenia as a consequence of an inability of megakaryocytes, once formed, to properly mature and produce sufficient platelets. The Plt12 mouse is a model of high O 2 -affinity hemoglobinopathy and provides insights into hematopoiesis under conditions of chronic hypoxia.
Materialart:
Online-Ressource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1119146109
Sprache:
Englisch
Verlag:
Proceedings of the National Academy of Sciences
Publikationsdatum:
2012
ZDB Id:
209104-5
ZDB Id:
1461794-8
SSG:
11
SSG:
12
