title: Hydroxyurea therapy of a murine model of sickle cell anemia inhibits the progression of pneumococcal disease by down-modulating E-selectin.
abstract: Sickle cell anemia is characterized by chronic hemolysis coupled with extensive vascular inflammation. This inflammatory state also mechanistically promotes a high risk of lethal, invasive pneumococcal infection. Current treatments to reduce vaso-occlusive complications include chronic hydroxyurea therapy to induce fetal hemoglobin. Because hydroxyurea also reduces leukocytosis, an understanding of the impact of this treatment on pneumococcal pathogenesis is needed. Using a sickle cell mouse model of pneumococcal pneumonia and sepsis, administration of hydroxyurea was found to significantly improve survival. Hydroxyurea treatment decreased neutrophil extravasation into the infected lung coincident with significantly reduced levels of E-selectin in serum and on pulmonary epithelia. The protective effect of hydroxyurea was abrogated in mice deficient in E-selectin. The decrease in E-selectin levels was also evident in human sickle cell patients receiving hydroxyurea therapy. These data indicate that in addition to induction of fetal hemoglobin, hydroxyurea attenuates leukocyte-endothelial interactions in sickle cell anemia, resulting in protection against lethal pneumococcal sepsis.
authors: Department of Hematology, St Jude Children's Research Hospital, Memphis, TN, USA.
authors: Jeffrey D
authors: JD
authors: Lebensburger
authors: Thad
authors: T
authors: Howard
authors: Yunming
authors: Y
authors: Hu
authors: Tamara I
authors: TI
authors: Pestina
authors: Geli
authors: G
authors: Gao
authors: Melissa
authors: M
authors: Johnson
authors: Stanislav S
authors: SS
authors: Zakharenko
authors: Russell E
authors: RE
authors: Ware
authors: Elaine I
authors: EI
authors: Tuomanen
authors: Derek A
authors: DA
authors: Persons
authors: Jason W
authors: JW
authors: Rosch
mesh_terms: D000755:Anemia, Sickle Cell / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism; D000818:Animals; D000986:Antisickling Agents / Q000627:therapeutic use; D002648:Child; D004195:Disease Models, Animal; D019040:E-Selectin / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use*; D007150:Immunohistochemistry; D008168:Lung / Q000187:drug effects / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008856:Microscopy, Fluorescence; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology; D011018:Pneumonia, Pneumococcal / Q000150:complications / Q000517:prevention & control*; D016019:Survival Analysis
chemical_list: D000986:Antisickling Agents; D019040:E-Selectin; D006918:Hydroxyurea