Hydroxyurea and a cGMP-amplifying agent have immediate benefits on acute vaso-occlusive events in sickle cell disease mice

Camila Bononi Almeida, Christoph Scheiermann, Jung Eun Jang, Colette Prophete, Fernando Ferreira Costa, Nicola Conran, Paul S. Frenette

Research output: Contribution to journalArticlepeer-review

73 Scopus citations


Inhibition of leukocyte adhesion to the vascular endothelium represents a novel and important approach for decreasing sickle cell disease (SCD) vaso-occlusion. Using a humanized SCD-mouse-model of tumor necrosis factor-α-induced acute vaso-occlusion, we herein present data demonstrating that short-term administration of either hydroxyurea or the phosphodiesterase 9 (PDE9) inhibitor, BAY73-6691, significantly altered leukocyte recruitment to the microvasculature. Notably, the administration of both agents led to marked improvements in leukocyte rolling and adhesion and decreased heterotypic red blood cell-leukocyte interactions, coupled with prolonged animal survival. Mechanistically, these rheologic benefits were associated with decreased endothelial adhesion molecule expression, as well as diminished leukocyte Mac-1-integrin activation and cyclic guanosine monophosphate (cGMP)-signaling, leading to reduced leukocyte recruitment. Our findings indicate that hydroxyurea has immediate beneficial effects on the microvasculature in acute sickle-cell crises that are independent of the drug's fetal hemoglobin-elevating properties and probably involve the formation of intravascular nitric oxide. In addition, inhibition of PDE9, an enzyme highly expressed in hematopoietic cells, amplified the cGMP-elevating effects of hydroxyurea and may represent a promising and more tissue-specific adjuvant therapy for this disease.

Original languageEnglish (US)
Pages (from-to)2879-2888
Number of pages10
Issue number14
StatePublished - Oct 4 2012

ASJC Scopus subject areas

  • Biochemistry
  • Immunology
  • Hematology
  • Cell Biology


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