[Expression and significance of hypoxia-inducible factor-1α in lung tissues of obesity-asthma rat].
Parole chiave
Astratto
OBJECTIVE
To evaluate the expression level of hypoxia-inducible factor-1α (HIF-1α) in the rat model of diet-induced obesity and asthma.
METHODS
Forty male specific pathogen-free SD rats were randomly divided into four groups: normal body mass control group (group A), asthmatic rats with normal body mass (group B), obese control group (group C) and obese asthmatic rats (group D). The rats in both group A and B were fed basic diet, while those in group C and D were fed high-fat diet in order to establish diet-induced obese rat model. Rats in group B and D were sensitized and challenged with chicken ovalbumin (OVA) to establish the asthmatic model. The white cell count in bronchoalveolar lavage fluid (BALF) was performed. The total area of the airway wall (Wat) was measured by ImagePro Plus software and was standardized by the basement membrane perimeter (Pbm). The expression of HIF-1α in lung tissue was detected by immunohistochemistry. The concentration of HIF-1α in serum was determined by ELISA. The relationships of the total white cells in BALF and airway wall thickness (WAt/Pbm) with the expression of HIF-1α were analyzed by Pearson correlation analysis.
RESULTS
The total number of white cells in BALF in group D was (98.0±5.5)×10(4)/mL, which was significantly higher than those in group A (24.7±3.3)×10(4)/mL, group C (26.1±3.8)×10(4)/mL and group B (87.8±7.1)×10(4)/mL. The thickness of airway wall (WAt/Pbm) in group D was (9.91±0.56)m(2)/m, which was significantly higher than those in group A (6.11±0.99)m(2)/m and group C(5.99±0.83)m(2)/m, but when compared with that in group B (8.60±0.53)m(2)/m, there was no significant difference. The percentage of HIF-1α positive cells in group D was (19.44±0.96)%, which was significantly higher than those in group A (2.19±0.91)%, group C(2.56±0.89)% and group B (18.25±1.29)% (all P<0.05). The expression of HIF-1α in blood serum and BALF in group D were respectively(29.107±1.576) ng/mL and (0.511±0.011) ng/mL, which were significantly higher than those in group A [(19.380±1.506) ng/mL and (0.280±0.008) ng/mL, respectively], group C [(20.782±2.034) ng/mL and (0.281±0.010) ng/mL, respectively] and group B [(23.961±1.565) ng/mL and (0.397±0.011) ng/mL, respectively]. The expression of HIF-1α was positively correlated with the total number of white cells in BALF and the airway wall thickness.
CONCLUSIONS
The expression of HIF-1α in serum and lung tissue from obese asthmatic rats significantly increases, which is positively correlated with the total number of white cells in BALF and the airway wall thickness.
