The effect of adipose-derived stem cells on the lung colonization, TNF-α and IL-4 in rats with LPS-induced acute lung injury

Abstract

Objective To explore the effect of 5-ethynyl-2'-deoxyuridine (EdU) -labeled adipose-derived stem cells (ADSCs) on lung colonization, TNF-α and IL-4 in rats induced by lipopolysaccharide (LPS) with acute lung injury. Methods Thirty male Sprague-Dawley (SD) rats were randomly divided into the normal control group (n=10), LPS model group (n=10), and LPS+ADSCs intervention group (n=10). The ALI model rats were intraperitoneally injected with 8 mg/kg LPS, rats in the normal control group were intraperitoneally injected with 4 mL/kg physiological saline, and rats in the LPS+ADSCs group were intravenously injected with 300 μL ADSCs by tail vein after 30 minutes for the ALI model establishment, and rats in the normal control group and LPS group were intravenously injected with 300 μL physiological saline by tail vein. The time of death in rats was observed, lung tissue and blood from left ventricular were collected, and the serum tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-4) were detected by Enzyme-linked immunosorbent assay (ELISA). Lung wet/dry weight (W/D) ratio was detected by thoracotomy, the pathological changes of lung tissue were observed under optical microscope, and the colonization of ADSCs in the lungs were observed under immunofluorescence microscopy. LSD-t method was used to compare between every two groups. Results There was no significant difference in mortality between the LPS group and LPS + ADSCs group (50% vs. 70%, P> 0.05); EdU-labeled ADSCs were extensively colonized in the lungs by tail vein injection after 24 h; Compared with the normal control group, the lung injury of the LPS group was heavier, the ratio of lung W/D and TNF-α were significantly increased (all P< 0.01), and IL-4 level was significantly decreased (P< 0.01). Compared with the LPS model group, the degree of lung injury in the LPS + ADSCs group was significantly reduced, lung W/D ratio (5.57±0.27 vs. 5.98±0.28) and TNF-α level of blood [(41.51±4.14)ng/L vs. (45.52±3.74)ng/L] were significantly reduced (all P< 0.05), whereas the IL-4 levels were significantly increased [(7.01±1.11)pg/mL vs. (3.27±0.54)pg/mL, P< 0.05]. Conclusions EdU-labeled ADSCs could be colonized in the lungs of LPS-induced ALI rats, reduce the inflammatory response from TNF-α and improve the anti-inflammatory response from IL-4. Key words: Acute lung injury; Adipose-derived stem cell; Lipopolysaccharide; EdU; Tracer