Effect of microRNA-21-5p on hyperoxic acute lung injury in rats
10.3969/j.issn.1008-9691.2015.01.006
- VernacularTitle:微小RNA-21-5p对大鼠高氧性急性肺损伤的影响
- Author:
Guoyue LIU
;
Miao CHEN
;
Hui JI
;
Song QIN
;
Hong MEI
;
Tao CHEN
;
Huajun CHEN
- Publication Type:Journal Article
- Keywords:
miRNA-21-5p;
Hyperoxic acute lung injury;
Oxygenation index;
Respiratory index;
Lung wet/dry weight ratio
- From:
Chinese Journal of Integrated Traditional and Western Medicine in Intensive and Critical Care
2015;(1):23-27
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of microRNA-21-5p (miR-21-5p) on hyperoxic acute lung injury (HALI) in rats and provide a theoretical basis for HALI gene therapy. Methods One hundred and sixty Sprague-Dawley (SD) rats were randomly divided into four groups with number table:hyperoxia control group, phosphate buffer saline (PBS) group, blank virus group and miRNA-21-5p group (each, n = 40). The rats in hyperoxia control group were fed directly in the hyperoxia box (oxygen concentration > 90%); in the other three groups, 200 μL PBS, 200μL slow virus and 200μL miRNA-21-5p slow virus were dropped into the nose respectively, and then they were fed in the hyperoxia box. The rats were exposed to hyperoxia in the boxes for 0, 24, 48 and 72 hours in all the groups, and at each time point, 10 rats were taken randomly from each group to perform arterial blood-gas analysis, calculate oxygenation index (OI) and respiratory index (RI). Afterwards the rats were sacrificed by blood-letting from carotid artery under intra-peritoneal anesthesia, and the lung tissues were obtained to measure the left lung wet/dry weight (W/D) ratio, hemotoxylin-eosin (HE) staining was made and the pathological changes of the right lung were observed under light microscope and the pathological score was measured. Results At 0 hour, the OI, RI, lung W/D ratio and the lung tissue pathology score in rats with hyperoxic injury had no statistically significant differences among the four groups (all P>0.05). With the extension of time, the level of OI was gradually reduced, and the levels of RI, pathologic score and W/D ratio of lung tissues were gradually increased. Compared with the hyperoxia control group, in miRNA-21-5p group, the levels of OI were increased significantly at 24, 48 and 72 hours after the exposure to hyperoxia [mmHg (1 mmHg = 0.133 kPa): 24 hours 358.10±29.25 vs. 306.19±37.23, 48 hours 336.67±29.27 vs. 269.70±29.00, 72 hours 323.81±19.05 vs. 203.81±43.40, all P < 0.05], whereas the levels of RI were decreased significantly (24 hours 0.23±0.05 vs. 0.31±0.06, 48 hours 0.28±0.07 vs. 0.38±0.06, 72 hours 0.30±0.04 vs. 0.46±0.07, all P <0.05), the pathologic scores were decreased significantly (24 hours 0.60±0.52 vs. 0.90±0.74, 48 hours 1.30±0.95 vs.2.90±1.20, 72 hours 1.90±0.88 vs. 4.70±1.57, all P < 0.05) and the levels of W/D ratio were decreased obviously (24 hours 3.77±0.38 vs. 4.14±0.46, 48 hours 3.83±0.31 vs. 4.56±0.34, 72 hours 3.89±0.31 vs. 5.32±0.27, all P<0.05). Compared with the hyperoxia control group, the index results of the PBS group and the blank virus group after staying in the box had no statistical significant differences at each time point (all P>0.05). Under the optical microscope, along with the prolongation of exposure to hyperoxia, the structure of alveoli was gradually disturbed, their walls fractured and damaged, alveolar septa widened, edematous, infiltrated with inflammatory cells and in part of the rats a small amount of red blood cell exudates could be seen, but the degree of lung pathological injury in miRNA-21-5p group was much milder than that of the other groups. Conclusion The rat persistently exposed to hyperoxia for 24 hours can establish the rat model of HALI successfully, and the miRNA-21-5p can protect the lung tissue from the damage to some degrees in HALI rats.
