Mesenchymal stem cells local transplantation in abdominal aorta in rabbit and TIS effect on stenosis of the aorta andα-smooth muscle actin expression

Objective The aim of this study was to evaluate the effect of human umbilical cord mesenchymal stem cell transplantation on the degree of intima, middle membrane and lumen stenosis after abdominal aorta injury in rabbits. Methods Twenty male 20 New Zealand white rabbits were divided into control group and experimental group with each 10 rabbits. The abdominal aorta injury models were made by balloon dilation in two groups. In the experimental group, the 1×107/kg umbilical cord mesenchymal stem cells were injected into the vascular of the abdominal aorta of the rabbit from the side hole of the balloon catheter. The control group was injected with the same amount of normal saline by the same method. 4 weeks after, the rabbit were killed, rabbit abdominal aorta intimal thickness (IT), intimal area (IA), vascular media thickness (MT) and area (MA) and the degree of stenosis were measured and compared between the two groups; The α-smooth muscle actin (α-SMA) expression in rabbit vascular smooth muscle were compared between two groups. Results The IT [(1.63±0.29) mm vs. (0.68±0.11) mm, t=9.680, P=0.0001], IA [(4.11±1.23) mm2 vs. (1.42±0.56) mm2,t=6.290, P=0.0001], MT [(2.31±0.47) mm vs. (1.88±0.31) mm, t=2.420, P=0.026] and MA [(6.32±1.66) mm2 vs. (4.02±1.06) mm2,t=3.690, P=0.0017] in experiment group were significant lower than that of control group. The degree of stenosis in the control group and the test group were (72.2±8.4)% and (35.0±8.6)% respectively with statistical difference (t=9.790, P=0.000); α-SMA was brownish brown granules under optical microscope with the positive expression rate of 0.12±0.04 and 0.48±0.05 in the control and experiment groupers respectively with statistical difference (t=17.780, P=0.0001). Conclusion Human umbilical cord mesenchymal stem cell transplantation can significantly reduce the degree of vascular stenosis after abdominal aorta injury in rabbit and promote the expression of alpha -SM-actin in the membrane. Key words: Umbilical cord mesenchymal stem cells; Abdominal aorta injury; Arterial stenosis