Ursodeoxycholic acid ameliorates cell migration retarded by the SARS-CoV-2 spike protein in BEAS-2B human bronchial epithelial cells.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is caused by severe acute -respiratory syndrome coronavirus 2 (SARS- CoV-2) through interaction of the spike protein (SP) with the receptor-binding domain (RBD) and its receptor, angiotensin converting enzyme 2(ACE2). Repair mechanisms induced following virus infection can restore the protective barrier through wound healing. Then, cells from the epithelial basal layer repopulate the damaged area, followed by cell proliferation and differentiation, as well as changes in gene expression. METHODS: Using Beas-2B cells and SP, we investigated whether ursodeoxycholic acid (UDCA) contributes to restoration of the bronchial epithelial layer. ACE2 expression was measured by RT-PCR and Western blotting. SP-ACE2 interaction was analyzed by flow cytometry and visualized through immunostaining. Cell migration was assessed using single cell path tracking and wound healing assay. RESULTS: Upon ACE2 overexpression in HeLa, HEK293T, and Beas-2B cells following the transfection of pCMV-ACE2 plasmid DNA, SP binding on each cell was increased in the ACE2 overexpression group compared to pCMV-transfected control cells. SP treatment delayed the migration of BEAS-2B cells compared to the control. SP also reduced cell migration, even under ACE2 overexpression; SP binding was greater in ACE2-overexpressed cells than control cells. UDCA interfered significantly with the binding of SP to ACE2 under our experimental conditions. UDCA also restored the inhibitory migration of Beas-2B cells induced by SP treatment. CONCLSION: Our data demonstrate that UDCA can contribute to the inhibition of abnormal airway epithelial cell migration. These results suggest that UDCA can enhance the repair mechanism, to prevent damage caused by SP-ACE2 interaction and enhance restoration of the epithelial basal layer.

Primary Cilium by Polyinosinic:Polycytidylic Acid Regulates the Regenerative Migration of Beas-2B Bronchial Epithelial Cells.

The airway epithelium is equipped with the ability to resist respiratory disease development and airway damage, including the migration of airway epithelial cells and the activation of TLR3, which recognizes double-stranded (ds) RNA. Primary cilia on airway epithelial cells are involved in the cell cycle and cell differentiation and repair. In this study, we used Beas-2B human bronchial epithelial cells to investigate the effects of the TLR3 agonist polyinosinic:polycytidylic acid [Poly(I:C)] on airway cell migration and primary cilia (PC) formation. PC formation increased in cells incubated under serum deprivation. Migration was faster in Beas-2B cells pretreated with Poly(I:C) than in control cells, as judged by a wound healing assay, single-cell path tracking, and a Transwell migration assay. No changes in cell migration were observed when the cells were incubated in conditioned medium from Poly(I:C)-treated cells. PC formation was enhanced by Poly(I:C) treatment, but was reduced when the cells were exposed to the ciliogenesis inhibitor ciliobrevin A (CilioA). The inhibition of Beas-2B cell migration by CilioA was also assessed and a slight decrease in ciliogenesis was detected in SARS-CoV-2 spike protein (SP)-treated Beas-2B cells overexpressing ACE2 compared to control cells. Cell migration was decreased by SP but restored by Poly(I:C) treatment. Taken together, our results demonstrate that impaired migration by SP-treated cells can be attenuated by Poly(I:C) treatment, thus increasing airway cell migration through the regulation of ciliogenesis.