Inhibition of Galectin-3 attenuates silica particles-induced silicosis via regulating the GSK-3β/β-catenin signal pathway-mediated epithelial-mesenchymal transition

Abstract

Silica is a very common and important chemical raw material with a wide range of uses. Long-term inhalation of silica particles could cause lung toxicity, of which the most important representative is silicosis. Silicosis is a serious and fatal occupational pulmonary disease, characterized by persistent pulmonary inflammation and fibrosis. Despite intensive research, the toxic mechanism of silicosis caused by silica particles is not completely clear, which deserves further research and exploration. Many studies have indicated that the epithelial cells partially participate in the formation, accumulation, and activation of fibroblasts through epithelial-mesenchymal transition (EMT), which is conducive to the occurrence of fibrosis. Galectin-3 (Gal-3), widely expressed in epithelial cells, was observed to induce EMT in fibrotic diseases and tumors by regulating the GSK-3β and β-catenin. Previous studies have demonstrated that silica particles is indeed involved in the silicosis process by inducing EMT. However, it remains to be further studied whether there is a certain relationship between silica particles and Gal-3 expression, and whether Gal-3 also mediates the development of the silica particles-induced silicosis by regulating GSK-3β/β-catenin signal pathway-mediated EMT. Our research results showed that silica particles could significantly induce Gal-3 expression to promote the development of EMT through activating the GSK-3β/β-catenin signal pathway in mice and in A549 cells, which then significantly exacerbated the pulmonary fibrosis caused by silica particles. And the inhibition of Gal-3 could effectively inhibit the occurrence of EMT, and then effectively alleviate silicosis caused by silica particles. These findings would help us to further clarify the toxicological mechanisms of silicosis caused by silica particles and provide a novel target for prevention and intervention of silicosis.

Keywords: Epithelial-mesenchymal transition; GSK-3β/β-catenin signal pathway; Galectin-3; Silica particles; Silicosis.