title: RNA aptamer therapy for vaso-occlusion in sickle cell disease.
abstract: Patients with sickle cell disease (SCD) often suffer painful vaso-occlusive episodes caused in part by the adhesion of sickle erythrocytes (SS-RBC) to the vascular endothelium. To investigate inhibition of SS-RBC adhesion as a possible treatment for vaso-occlusion, 2 adhesion molecules, α(v)β(3) and P-selectin, were targeted by high-affinity RNA aptamers. An in vitro flow chamber assay was used to test the antiadhesion activity of α(v)β(3) aptamer clone 17.16. Human SS-RBC were passed across a confluent monolayer of thrombin-stimulated human umbilical vein endothelial cells (HUVEC) at a constant rate. α(v)β(3) aptamer reduced SS-RBC adhesion to activated endothelial cells to the level seen with untreated HUVEC. An aptamer reactive with complement component 8 was used as a negative control and exerted no inhibition, confirming the specificity of α(v)β(3) aptamer (P=0.04). At 2 dyn/cm(2) shear stress, 30 nM α(v)β(3) aptamer showed maximal effect in decreasing SS-RBC adhesion to HUVEC. The antiadhesive activity of the P-selectin aptamer clone PF377 was also tested using HUVEC pretreated with IL-13 to upregulate expression of P-selectin as seen in activated endothelial cells. At 1 dyn/cm(2) shear stress, 60 nM of P-selectin aptamer had antiadhesion activity similar to heparin, a known inhibitor of SS-RBC adhesion to P-selectin. A negative control did not prevent adhesion (P=0.05). These data show the potential utility of aptamers to block endothelial adhesion molecules to prevent or treat vaso-occlusion in SCD.
authors.affiliation: Department of Surgery, Duke University Medical Center , Durham, NC 27710, USA.
authors.forename: Angela D
authors.initials: AD
authors.lastname: Burnette
authors.forename: Shahid M
authors.initials: SM
authors.lastname: Nimjee
authors.forename: Milena
authors.initials: M
authors.lastname: Batchvarova
authors.forename: Rahima
authors.initials: R
authors.lastname: Zennadi
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Telen
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Nishimura
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Sullenger
mesh_terms: D000755:Anemia, Sickle Cell / Q000188:drug therapy* / Q000473:pathology; D000986:Antisickling Agents / Q000494:pharmacology* / Q000627:therapeutic use; D052157:Aptamers, Nucleotide / Q000494:pharmacology* / Q000627:therapeutic use; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D004912:Erythrocytes / Q000187:drug effects / Q000473:pathology; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D019007:P-Selectin / Q000378:metabolism
chemical_list: D000986:Antisickling Agents; D052157:Aptamers, Nucleotide; D039302:Integrin alphaVbeta3; D019007:P-Selectin