Objective To explore the treatment effect of bone marrow mesenchymal stem cells( BMSCs)transplantation in ratmodel of bleomycin-induced pulmonary fibrosis. Methods BMSCs fromten-day-old SDmale rat were cultured and marked with 4, 6-diamidino-2-phenylindole( DAPI) . Seventy female SD rats were randomly divided into four groups. Group A( n = 21) was intratracheally injected with saline as control. Group B( n = 21)were intratracheally injected with BLMA5 to establish pulmonary fibrosis. Group C( n = 21) was injected with BLMA5 intratracheally and BMSCs intravenously via tail vein simultaneously. Group D( n = 7) was injected with BMSCs 14 days after BLMA5 injection. The rats were sacrificed on 7th, 14th and 28th day respectively( rats of group D were on28th) . HE and Masson stainings were performed to observe lung pathological changes. Fluorocyte marked with DAPI was analyzed by fluorescent microscope. Sex determining region Y( SRY) gene were detected by PCR. The lung levels of HYP, tumor necrosis factor-α( TNF-α) and transforming growth factor-β1 ( TGF-β1 ) were measured by ELISA. Results ( 1) In group C and D, BMSCs marked with DAPI were detected in lung frozen section on 7th, 14th and 28th day, and SRY gene of male rats were detected by PCR. ( 2) Alveolitis was most obvious on 7th day and pulmonary fibrosis was most severe on 28th day in group B compared to other three groups( P lt;0. 05 or 0. 01) . Alveolitis and pulmonary fibrosis in group C and D were significantly alleviated compared to group B( P lt; 0. 05) , but still more severe than group A( P lt; 0. 05 or 0. 01) , which in group D was more severe compared to group C( P lt;0. 05) . ( 3) HYP level in group B, coincided with fibrosis, began to increase on7th day and reached the peak on 28th day, significantly higher than other three groups( P lt;0.05 or 0. 01) . TNF-αlevel in group B was highest on 7th day, then descended, which was significantly higher than group A and C on 14th day and not obviously different from other three groups on 28th day. TGF-β1 level in group B was highest on 28th day which was different significantly fromother three groups. Conclusion BMSCs can colonize in the recipient lung tissue and effectively prevent the development of pulmonary fibrosis of rats induced by BLMA5, especially in the early stage.
Objective To explore the migration and differentiation of bone marrow mesenchymal stem cells（MSCs） in lung . Methods MSCs were harvested from a male Wister rat. Sixty female Wister rats were randomly divided into four groups. The pulmonary fibrosis model was established by intratracheal instillation of bleomycin in group A-D. Immediately and 7 days after bleomycin administration respectively，the rats in group B and C received infusion with 5-bromodeoxynridine （BrdU） labeled MSCs via tail vein. And the rats in group D were infused MSCs without BrdU labeling serving as a negative control. The sry gene of Y chromosome was detected by polymerase chain reaction （PCR）. Double immunofluorescence staining was used to detected BrdU and surfactant associated protein-C （SP-C） expression in lung tissue，fresh bone marrow，and the 5th generation MSCs. Reverse transcriptipon-PCR was used to detect the expressions of SP-C mRNA and AQP-5 mRNA. Results The sry gene was detected in bleomycin induced lung injury tissues of the rats after MSCs infusion immediately and on the 7th day The MSCs in lung tissue could transformed into cells with ACEⅡ morphological features and molecular phenotype. The transformation rate was higher in the rats received MSCs infusion immediately than the rats received on 7th day. The 5th generation MSCs and fresh bone marrow expressed SP-C mRNA，without AQP-5 mRNA and SP-C expression. Conclusions Exogenous MSCs can be transplanted into injured lung tissues and transform into AECⅡ，especially in early stage of lung injury. The differentiation potential of MSCs can be activated in injury micro-environment.
ObjectiveTo investigate the effect of diammonium glycyrrhizinate (DG) plus bone marrow mesenchymal stem cells (MSCs) transplantation in the treatment of acute exacerbation of pulmonary fibrosis induced by bleomycin (BLM) in rats.MethodsMSCs were isolated from male Wistar rats and cultured in vitro. Twenty-four female Wistar rats were randomly divided into 4 groups. The NC group was intratracheally injected with normal saline; the BLM group, the MSC group and the DGMSC group were intratracheally injected with BLM for 7 days; then the MSC group was injected with 0.5 mL of MSCs solution (2.5×106 cells) into the tail vein; the DGMSC group was intraperitoneally injected with DG for 21 days in a dose of 150 mg·kg–1·d–1 on the base of the MSCs injection. The rats were sacrificed on the 28th day and the lung tissue was extracted. Pathological examination was performed to determine the degree of alveolitis and pulmonary fibrosis. Immunofluorescence was used to detect the number and distribution of alveolar type Ⅱ epithelial cells. Alkali hydrolysis method was used to determine the content of hydroxyproline (HYP) in lung tissue; thiobarbituric acid method was used to measure the content of malondialdehyde (MDA) in lung tissue; colorimetric method was used to determine the superoxide dismutase activity (SOD) and total antioxidant capacity (T-AOC); enzyme linked immunosorbent assay was used to detect the expression levels of tumor necrosis factor-α (TNF-α ) and transforming growth factor-β1 (TGF-β1) in lung tissue homogenates.ResultsThe DG combined with MSCs injection can reduce the degree of alveolitis and pulmonary fibrosis in BLM model rats. The content of HYP and TGF-β1 in lung tissue homogenate of the DGMSC group were significantly lower than those in the MSC group (P<0.05). Meanwhile, DG combined with MSCs injection significantly increased the antioxidant capacity of the BLM model rats. MDA content decreased, SOD activity and T-AOC ability improved significantly in the DGMSC group compared with the MSC group (P<0.05). The alveolar type Ⅱ epithelial cells were significantly increased and the cell morphology was maintained in the DGMSC group compared with the MSC group.ConclusionsDG has a synergistic effect with MSCs in treatment of acute exacerbation of pulmonary fibrosis. The mechanism may be related to reducing inflammatory factors during pulmonary fibrosis, attenuating oxidative stress and promoting MSCs migration into lung tissue and transformation to alveolar type Ⅱ epithelial cells.