Objective        To investigate the effect of survivin-modified bone marrow mesenchymal stem cells (BM

SC) on lung fibrosis in mice.       Methods        The BMSC obtained from C57BL/6 mice were cultured

in vitro

and transfected with both survivin and green fluorescent protein (GFP) and GFP alone by lentiviral vectors

respectively. The cell apoptotic rate was detected by flow cytometry. Forty-eight C57BL/6 mice were randomly divided into 3 groups: a BMSC-survivin group (A)

a BMSC group (B) and a model group (C). Mouse pulmonary fibrosis models were induced by bleomycin 5 mg/kg

via

single intratracheal perfusion. Twenty-four hours after model establishment

the mice in group A

group B and group C were injected with 1×10

6

BMSC-survivin

1×10

6

BMSC

and normal saline through caudal vein

respectively. On the 7th and 28th day

every 8 mice were sacrificed from each group

and the lung tissues were sectioned and observed by HE staining. The surfactant protein A (SP-A) was measured by immunohistochemistry

the serum content of hydroxyproline (Hyp) was measured by ELISA

and the mRNA expression of transforming growth factor (TGF)-β1 and matrix metalloproteinase (MMP)-9 in lung tissues was detected by RT-PCR.       Results        The apoptotic rates of BMSC and BMSC-survivin were (14.466±1.953)% and (7.718±0.493)%

respectively. For mice receiving BMSC

the lung fibrosis was slighter than that of the group C. The Hyp contents of the 3 groups were 0.106±0.012

0.245±0.009 and 0.324±0.002 μg/mL on the 7th day and 0.457±0.006

0.752±0.012 and 1.372±0.035 μg/mL on the 28th day

respectively. The SP-A contents of the 3 groups were 0.718±0.018

0.669±0.013 and 0.581±0.027 on the 7th day and 0.433±0.012

0.372±0.039 and 0.277±0.013 on the 28th day

respectively. The mRNA expression levels of TGF-β1 and MMP-9 at each time point were lower in the group A than in the group B

and those of the group B were lower than those of the group C.       Conclusion       Exogenous BMSC is effective in preventing bleomycin-induced lung fibrosis

and survivin can enhance the activity of BMSC.