Updated project metadata.
SARS-CoV-2 seriously injures human alveoli and causes severe respiratory illness. Histopathologic evidences suggested alveolar-capillary barrier integrity is compromised in COVID-19 deaths, however, little is known about how it is disrupted. In this study, we investigated the effects of SARS-CoV-2 infection on alveolar epithelium and pulmonary microvascular endothelium, and tried to elucidate the cross-talk between them during viral infection. Under monoculture system, SARS-CoV-2 infection caused massive virus replication and dramatic organelles re-modeling in alveolar epithelial cells. While, as for pulmonary microvascular endothelial cells, direct viral exposure had little effect on them, but treatment with culture supernatant from infected epithelial cellls significantly damaged them, which suggested SARS-CoV-2 affected endothelium indirectly, possibly by substances released from infected alveolar epithelium. Then, we tested SARS-CoV-2 infection in an alveolar epithelium/endothelium co-culture system, and found viral infection caused global proteomic modulations and ultrastructual changes in both cell types. Especially for alveolar epithelial cells, viral infection elicited significant protein changes and structural reorganizations across many sub-cellular compartments. Among the affected organelles, mitochondrion seems to be a primary target organelle. In addition, based on proteomic analysis and EM clues, we tested several autophagy inhibitors, and discovered one of them, Daurisoline, could inhibit virus replication effectively in cells. Collectively, our study revealed the distinctive responses of alveolar epithelium and microvascular endothelium to SARS-CoV-2 infection, which will expand our understanding of COVID-19 andĀ helpful for targeted drug development.