Establishment of a juvenile mouse asthma model induced by postnatal hyperoxia exposure combined with early OVA sensitization.

Objective: To establish a juvenile mouse asthma model by postnatal hyperoxia exposure combined with early ovalbumin (OVA) sensitization.

Methods: Female C57BL/6J newborn mice were exposed to hyperoxia (95 % O) from postnatal day-1 (PND1) to PND7; intraperitoneally injected with OVA suspension on PND21, PND28; and stimulated by nebulized inhalation of 1 % OVA from PND36 to PND42. Within 48 h of the last challenge, we observed their activity performance and evaluated airway responsiveness (AHR). All mice were executed at PND44. Female (n = 32) were divided into four groups as follows: room air（RA）+phosphate-buffered saline (PBS) group; O (hyperoxia, 95 % O) + PBS group; RA + OVA group; O+OVA group. We obtained the serum, bronchoalveolar lavage fluid (BALF), and lung tissues. The Wright-Giemsa staining was performed for leukocyte classification in BALF and HE staining for pathological examination. The levels of IL-2, IL-5, IL-13, IL-17A and IL-10 in BALF and tIgE and sIgE in serum were detected by ELISA.

Results: Compared with OVA sensitization or hyperoxia exposure alone, the mice in the model group (O+OVA) showed asthma-like symptoms and increased airway hyperreactivity,The levels of IL-5,IL-13 IL-17A were increased in BLAF,and total leukocyte and eosinophil counts were also significant increasesed. The levels of tIgE and sIgE in serum were increased.

Conclusion: Postnatal hyperoxia exposure combined with early OVA sensitization might establish a juvenile mouse asthma model.