OBJECTIVETo observe the effect of bone marrow mesenchymal stem cell transplantation on postangioplasty aortic restenosis in rats.

METHODS48 SD rats were randomly divided into normal control group, balloon injury group, balloon injury and MSCs transplantation group. MSCs were pre-labeled by DAPI (25 microg/ml) and then infused into aorta through the balloon catheter (MSCs 2 x 10(6)/animal). Thoracic aorta were taken for histological examination (frozen and paraffin sections) at 1, 2, 6 weeks post angioplasty, respectively. DAPI labeled MSCs were detected under immunofluorescence microscopy. Expressions of c-kit, proliferating cell nuclear antigen (PCNA), smooth muscle alpha-actin (alpha-SMA) in aorta were determined by immunocytochemistry using related antibodies.

RESULTSThe DAPI-labeled MSCs could be detected on impaired intimae and alpha-SMA expression was seen in these cells 1 weeks after MSCs transplantation. Similar weak c-kit expression in neointima was found in both injury and transplantation group at 2 weeks (P > 0.05). Expressions of PCNA and alpha-SMA in the neointima were significantly higher in transplantation group than in injury group at 2 weeks. Intima/tunica media area ratio and luminal stenosis ratio were significantly increased in transplantation group than injury group at 6 weeks (all P < 0.05).

CONCLUSIONBone marrow MSCs transplanted post aortic angioplasty could home to serious wounded aortic intima, differentiate into smooth muscle like cells, promote neointima cellular proliferation and aggravate postangioplasty aortic restenosis in rats.