NLRP3 and inflammation: Jiang et al. investigated whether ER stress during simulated microgravity induced endothelial inflammation and apoptosis in HUVECs (human umbilical vein endothelial cells), and they found that the increase of apoptosis in HUVECs during clinorotation was significantly suppressed by inhibiting ER stress, iNOS activity, NF-κB/IκB, and the NLRP3 inflammasome signaling pathway, indicating ER stress-dependent activation of iNOS/NO-NF-κB signaling and NLRP3 inflammasome contributes to chronic injury endothelial inflammation and apoptosis associated with microgravity (Jiang et al., 2020).