[Transplantation of marrow mesenchymal stem cells transfected with vascular endothelial growth factor gene for the treatment of pulmonary hypertension in rats].

OBJECTIVE

To explore the therapeutic effect and the mechanism of marrow mesenchymal stem cells (MMSCs) transfected with vascular endothelial growth factor (VEGF) gene in the treatment of pulmonary hypertension in rats.

METHODS

MMSCs from the bone marrow of Sprague-Dawley rats were isolated, cultured and propagated in vitro. pIRES2-EGFP-VEGF165 was transfected into MMSC. The healthy male SD rats were divided randomly into 4 groups: normal control group, pulmonary hypertension model group, MMSCs transplantation group and transfer gene transplantation group. A single subcutaneous monocrotaline (50 mg/kg) was injected to induce the model of pulmonary hypertension. The normal control group received a single subcutaneous dose of L-DMEM (low glucose Dulbecco's modified Eagle's medium). All four groups of rats were fed similarly. At Day 21 post-modeling, 5 × 10(6) MMSCs in l ml L-DMEM were injected into the MMSC group. 5 × 10(5) MMSC transfected by pIRES2-EGFP-VEGF165 were injected into the gene transplantation group. A same volume L-DMEM solution was also injected into the pulmonary hypertension model group and normal control group. The parameters of right ventricular systolic pressure (RVSP), right ventricular hypertrophy index, blood gas analysis and microstructure as well as pulmonary microvascular changes were observed after 30 days.

RESULTS

At Day 30 post-transplantation of MMSCs, the outcomes were as follows: RVSP was (30.2 ± 2.1) and (29.2 ± 1.1) mm Hg (1 mm Hg = 0.133 kPa) in the MMSCs transplantation and gene transplantation groups respectively. The right ventricular hypertrophy indices were (37.9 ± 3.2)% and (27.2 ± 3.4)% respectively. The media thickness of pulmonary artery (MT) was (21.3 ± 3.4) and (14.3 ± 2.8) µm respectively. The ratios of vascular area to total arterial area (V/T) were (39.3 ± 4.3)% and (43.0 ± 1.5)% respectively. As compare with the pulmonary hypertension model group, the above parameters were of statistical significances (P < 0.01). A comparison of right ventricle hypertrophy index, MT and V/T was of statistical significance between MMSC and gene transplantation groups (P < 0.05). The blood gas analysis of the MMSCs transplantation and gene transplantation groups were better than the pulmonary hypertension mode group. Ultramicrostructure showed that neovascularization and small pulmonary arterial repair appeared in two transplantation groups.

CONCLUSION

MMSCs transfected by pIRES2-EGFP-VEGF165 transplantation may improve and reverse the MCT-induced progress of pulmonary hypertension in rats. And it is better than the MMSC transplantation. The potential mechanism is through arterial repair and neovascularization.