Adipose-Derived Stem Cell Secretome Attenuates Eosinophilic Inflammation in a Chronic Rhinosinusitis with Nasal Polyps Mouse Model

Adipose-derived stem cells (ASCs) and their secretome have been reported to improve allergic airway inflammation. Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is characterized by type 2 helper T (Th2)-diven inflammation, which shares similar mechanisms with allergic airway diseases. We assessed the immunomodulatory effects of ASC secretome on an ECRSwNP mouse model. ECRSwNP was induced by ovalbumin (OVA) and <i>Staphylococcus aureus</i> enterotoxin B (SEB) intranasal challenges in five-week-old BALB/c mice. To evaluate the effect of ASC secretome on eosinophilic nasal inflammation, 10 μg/50 μL of ASC-conditioned media were administered three times a week during the eight weeks. H&E and Sirius red staining were performed to evaluate the formation of nasal polyps (NPs) and the infiltration of eosinophils. The cytokine levels of interleukin (IL)-4, IL-5, IL-13, interferon-γ, IL-8, and eotaxin-1 were measured using ELISA(eBiosciences, San Diego, CA, USA). The expression levels of IL-8 and eotaxin-1 mRNA were determined by quantitative PCR. Eosinophil cationic protein (ECP) and eotaxin-1 expression were assessed by immunohistochemistry. Intranasal administration of ASC secretome significantly decreased NP-like formation and eosinophilic infiltration in the sinonasal mucosa of ECRSwNP mice. The increased IL-4, IL-5, and eotaxin-1 levels after OVA + SEB challenge remarkably decreased by ASC secretome treatment. Furthermore, ASC secretome notably decreased the gene expression of eotaxin-1 by PCR, as well as ECP and eotaxin-1 expression by immunohistochemistry. ASC secretome had immunomodulatory effects in a mouse model of ECRSwNP. Intranasal administration of ASC secretome resulted in a significant reduction in NP formation and eosinophilic inflammation through the suppression of IL-4, IL-5, eotaxin-1, and ECP.