Transfusion of CXCR4-priming endothelial progenitor cells reduces cerebral ischemic damage and promotes angiogenesis and neurogenesis in db/db diabetic mice

Previous studies suggest that reduction and dysfunction of circulating endothelial progenitor cells(EPCs),and dysregulation in stromal cell derived factor-1/CXC-chemokine receptor 4(SDF-1/ CXCR4) axis in diabetes could be therapeutic targets for diabetic ischemic stroke.This study investigated the efficacy of CXCR4-priming EPCs on cerebral repair following ischemic stroke in db/db diabetic mice.Bone marrow derived EPCs from db/+ control mice were transfected with adenovirus(1×10~7 IU) carrying CXCR4(Ad-CXCR4-EPCs)or null(Ad- null-EPCs).The db/db mice were divided into three groups for EPCs injection(2×10~5 cells/100μl): Ad-CXCR4-EPCs,Ad-null-EPCs or saline(vehicle), via tail vein 2 hrs after middle cerebral artery occlusion (MCAO) surgery.Cerebral blood flow(CBF) was measured with laser Doppler flowmeter.Mice were sacrificed at 2 or 7 days thereafter.Level of circulating EPCs was measured by flow cytometry. Ischemic damage,cerebral microvascular density (MVD),angiogenesis and neurogenesis were determined by histological staining with Fluoro-J,CD31, CD31 +BrdU,NeuN +BrdU,GFAP+BrdU,respectively. Results(table) showed:1) Levels of CXCR4 expression were reduced in the brain and EPCs of db/db mice as measured by real-time RT-PCR and western blot analyses(data not shown);2) The level of circulating EPCs was more in the mice treated with Ad-CXCR4-EPCs;3)EPC transfusion improved CBF,increased MVD,angiogenesis and neurogenesis in peri-infarct area,and decreased ischemic damage.The efficacies were better in Ad-CXCR4 -EPCs group.Data suggest that transfusion of Ad-CXCR4-EPCs could be a therapeutic avenue for ischemia stroke in diabetes.