To investigate the effects of serine protease inhibitor 3n (SerpinA3n) in a neonatal mouse model of asthma.
The study utilized a neonatal mouse ovalbumin (OVA) sensitization model of asthma. Wild type (WT) and SerpinA3n mice were randomly divided into WT/SerpinA3n + saline, WT/SerpinA3n + OVA, WT/SerpinA3n + OVA + rSerpinA3n (recombinant mouse SerpinA3n protein), and WT/SerpinA3n + OVA + DEX (dexamethasone, positive control) groups followed by hematoxylin-eosin (HE) staining, Masson’s trichrome stainings, Sircol soluble collagen assay, quantitative real time polymerase chain reaction (qRT-PCR), Western Blot and enzyme linked immunosorbent assay (ELISA).
OVA-induced neonatal mice showed the increases in airway hyper-reactivity with the up-regulated total cells, eosinophil, lymphocyte and neutrophil in bronchoalveolar lavage fluid (BALF), which was much higher in WT + OVA + rSerpinA3n group (P <  0.05). SerpinA3n suppressed the serum concentrations of total immunoglobulin E (IgE) and OVA-specific IgG1 in OVA-induced asthmatic mice, and alleviated the pathological changes of lung tissues, which was reversed by rSerpinA3n injection (P <  0.05). Besides, WT + OVA group showed more severe in collagen deposition in lung tissues than SerpinA3n + OVA group with increased expression of matrix metallopeptidase-2 (MMP-2), MMP-9, Eotaxin-1, Interleukin 5 (IL-5), IL-13 and IL-4 in lung tissues and deceased IL-10 and Interferon-gamma (IFN-γ) (P <  0.05). Nevertheless, the ameliorating effects of SerpinA3n knockout on OVA-induced asthmatic mice can be reversed by rSerpinA3n.
SerpinA3n knockout can attenuate airway hyper-reactivity, mitigate inflammatory responses and reduce collagen deposition in lung tissues of neonatal mice with asthma.