Influence of ultrasound-mediated contrast agent microbubbles carrying kallidinogenase targeted therapy on neurogenesis and angiogenesis after experimental acute cerebral infarction / 中华神经科杂志

ABSTRACT

Objective To evaluate the influence of ultrasound-mediated contrast agent microbubbles carrying kallidinogenase targeted therapy on neurogenesis and angiogenesis after experimental acute cerebral infarction.Methods Kallidinogenase-loaded microbubbles were prepared using mechanical shaking method.Middle cerebral artery occlusion (MCAO) model was established in male Wistar rats by sutureoccluded method.MCAO rats (n =120) were randomly divided into 5 groupsultrasound-mediated kallidinogenase-loaded microbubbles group (group 1),ultrasound-mediated microbubbles group (group 2),ultrasound-mediated saline group (group 3),kallidinogenase group (group 4),saline group (group 5).Medication was given through tail vein daily for 2-6 consecutive days starting 24 h after MCAO.Ultrasound groups (groups 1,2 and 3) were given 2 MHz pulse ultrasonic irradiation on the ischemia lateral skull for 10 min after injection.Cell proliferation was examined using 5'-bromo-2'-deoxyuridine (BrdU,50 mg/kg).Infarction volume and neurological function were evaluated on the 3rd,7th day after MCAO respectively.Doublecortin (DCX) + cells in the subventricular zone and laminin + in the peri-infarction region were observed at the same time.Results The number of DCX + cells in the subventricular zone (under 20 × ocular) of groups 1-5 was 251.8 ± 13.1,125.7 ± 11.6,130.2 ± 13.7,234.5 ± 12.4 and 123.7 ± 10.0 respectively.The percentage of laminin + cells in the peri-infarction region (× 10 objective) of groups 1-5 was 10.0％ ± 0.8％,5.2％ ± 0.7％,5.0％ ± 1.0％,8.0％ ± 1.8％ and 5.0％ ± 0.9％ respectively.The number of DCX + cells in the subventricular zone and laminin + cells in the peri-infarction region of the group 1 and the group 4 was significantly more on the 7th day after MCAO compared with those of the other three groups (DCXt values of group 1 vs groups 2,3,5 were 17.88,17.17 and 18.16,all P ＜ 0.01 ; t values of group 4 vs groups 2,3,5 were 15.42,14.78 and 15.70,all P ＜0.01.Laminint values of group 1 vs groups 2,3,5 were 7.01,6.71 and 7.11,all P ＜ 0.01 ; t values of group 4 vs groups 2,3,5 were 4.23,3.94 and 4.33,all P ＜0.01).Moreover,the number of DCX+ cells in the subventricular zone (t =2.46,P ＜ 0.05) and laminin + cells in the peri-infarction region (t =2.78,P ＜ 0.05) of the group 1 was much more than those of the group 4.Neurologic scores on the 7th day of groups 1-5 were 1.00 (0.75,1.25),2.0 (2.00,3.00),2.0 (1.00,2.00),1.5 (0.75,2.00),2.0 (2.00,2.50).Compared with other four groups,group 1 showed better functional improvement after stroke (U values of group 1 vs groups 2-5 were 2.0,4.0,7.5 and 2.5,all P ＜ 0.05).While there was no significant difference in infarction volume among five groups at all the time points after MCAO.Conclusions Our study demonstrates ultrasound-mediated kallidinogenase-loaded contrast agent microbubbles targeted therapy promotes neuroblasts proliferation and vascular regeneration compared with mediated and non-medicine-loaded microbubbles therapy,which attributes to functional improvement after MCAO.Therefore,ultrasound-mediated ultrasound contrast agent microbubbles carrying drugs targeted therapy may have a perspective on ischemic stroke.