Combination of Merocel sponge with Lipopolysaccharide to establish rat rhinosinusitis model

OBJECTIVE: The study aimed to investigate the feasibility of establishing rhinosinusitis model in rats combinated with Lipopolysaccharide (LPS) and merocel sponge. METHODS: SD (Sprague Dawley) rats that underwent nasal obstruction using Merocel sponge packing, rats with LPS instillation alone, and rats with both nasal obstruction and LPS instillation were used to establish rat models of rhinosinusitis. After the models were established, the nasal symptoms of rats were recorded, the histopathological examination and Transmission Electron Microscopy (TME) of the sinus tissue were performed and the levels of Tumor Necrosis Factor-α (TNF-α), Interleukin-6 (IL-6) in the blood were also analyzed. The expressions of Aquaporin-5 (AQP5), Occludin, Toll-Like Receptor-4 (TLR4), Medullary differentiation factor 88 (MyD88) and phosphorylated (p)-p65 protein were detected by Western blot to evaluate the effect and mechanism of the experimental models. RESULTS: We found that compared with the control group and LPS group, the sinusitis symptom scores in the Merocel sponge combined with LPS group were significantly increased; the respiratory epithelia of the maxillary sinus were degenerated, cilia were detached, and even inflammatory cell infiltration occurred; the levels of TNF-α and IL-6 were increased; the expression of AQP5 and Occludin protein was decreased; and the expressions of TLR4, MyD88, and p-p65 protein were increased. CONCLUSION: For the first time, we successfully established a rat rhinosinusitis model using Merocel sponge with LPS and explored the possible mechanism of LPS action.