Analysis of mucus secretion and inflammatory process in in vitro model of human airway epithelial cells able - 09/06/21

Chronic Obstructive pulmonary disease (COPD) is a lung disease characterized by chronic inflammation, and mucus hypersecretion. Currently, curative treatment does not exist, and some patients develop resistance to corticosteroid drugs. Gene therapy could be a novel approach to treat the disease. However, the effectiveness of gene vectors in the airways is decreased by the presence of mucus that acts as a barrier. The aim of this study is to develop an in vitro model, able of cytokine production and mucus secretion; in the perspective of testing new drug including mucolytic gene therapy vectors.

We used three human airway epithelial lines (A549, Calu-3 and NCI-H292) stimulated with different concentrations of CSE (Cigarette Smoke Extract) alone or in association with LPS (lipopolysaccharides), for 24 or 48hours. NCI-H292 and Calu-3 cells were also co-cultured in the same conditions. Then, we evaluated MUC5AC, IL8/CXCL8, GROα/CXCL1 and MCP1/CCL2 gene expression by RT-qPCR and their secretion by ELISA. Finally, we also observed MUC5AC production from NCI-H292 by immunohistochemistry.

CSE alone or with LPS did not impact MUC5AC gene expression, in A549 cells. In contrast, LPS (0.1μg/mL) increased IL8/CXCL8, GROα/CXCL1 and MCP1/CCL2 release. When CSE associated with LPS, there was an additive effect on cytokine release.

Regarding Calu-3 cells, treatment with CSE, LPS, or both, did not affect MUC5AC gene expression, neither cytokine secretions. For NCI-H292 cells, CSE alone increased MUC5AC gene expression and an additive effect was observed when CSE was associated with LPS. LPS at low concentrations triggered some MUC5AC and IL8/CXCL8 release, which was more important when LPS was associated with CSE; but not for GROα/CXCL1. NCI-H292 cells did not release MCP1/CCL2. In the NCI-H292 and Calu-3 co-culture, CSE and LPS increased MUC5AC gene expression, but CSE did not affect cytokine secretion. LPS alone increased IL8/CXCL8 secretion, but not GROα/CXCL1 or MCP1/CCL2.

Our results show that NCI-H292 cells appear as the best model to evaluate the efficacy of gene vectors, as they are able to produce mucins and cytokines, after CSE and LPS exposure.