Abstract:

Objective: To observe the effect of APN-modified EPCs on brain tissue repair and neurological function recovery in ischemic stroke model mice. Methods: Construction of lentiviruses transfected with APN genes. Genetically modified EPCs overexpressing APN(EPC-APN) or green fluorescent protein (EPC-GFP) were transplanted into a mice model of transient middle cerebral artery occlusion (tMCAO). The EPC-APN transplantation group, EPC-green fluorescent protein (GFP) transplantation control group and phosphate buffer (PBS) control treatment group were established. After transplantation, the enhanced GFP-expressing cells were found at the peri-infact area of brain. At 1, 7 and 14 days after tMCAO, the infarct volume was measured by using cresyl violet. Angiogenesis in the perifocal region was quantified on the 14th day. The apoptosis of endogenous cells was evaluated using TUNEL assay. Expression of vascular endothelial growth factor（VEGF）was detected using Western blot. Results: By constructing APN gene lentiviral vectors to transfect to EPCs, EPCs overexpressing APN were successfully prepared. The volume of brain atrophy in the EPC-APN transplantation group on on the 14th day after cerebral ischemia was significantly reduced compared with that in the EPC-GFP transplantation control group and the PBS control treatment group (7.2%±0.9% vs 11.6%±1.2% vs 16.2%±2.1%, P<0.01). Compared with the control group, the number of apoptosis of endogenous cells in the EPC-APN transplantation group was significantly reduced (1.0%±0.1%/mm² vs 2.1%±0.2%/mm² vs 11.2%±3.2%/mm², P<0.05). Mice in the EPC-APN transplant group had lower neurobehavioral mNSS scores (3.2±0.3 vs 4.5±0.3 vs 5.8±0.5, P<0.05). The number of angiogenesis in the brain of the EPC-APN transplantation group increased significantly[(6.2±0.8)/mm² vs(1.8±0.2)/mm² vs (0.2±0.1)/mm², P<0.01]. Western blot analysis showed that the VEGF expression in EPC-APN group was up-regulated compared with EPC-GFP group (P<0.05). Conclusions: EPC-APN transplantation can reduce ischemic brain injury and improve neurobehavioral outcomes.

Key words: Adiponectin, End othelial progenitor cell, Ischemic stroke, Angiogenesis