Vacuolin-1 (1 μM; Pretreatment 1 hour) blocks ionomycin-induced exocytosis of lysosomes but not of enlargeosomes. It results in vacuolation of lysosomes (A) and complete inhibition of the surface expression of Lamp-1.
Vacuolin-1 (1 μM; 20-180 min) disrupts the segregation of inner and limiting membranes characteristic of endosomes and lysosomes. Ultrastructural analysis also shows that vacuolin-1 favours fusion of inner and limiting membranes.
Vacuolin-1 (5 or 10 μM; 2 hours) blocks the Ca-dependent release of β-hexosaminidase from lysosomes. In HeLa cells, ionomycin results in the expected release of 18-20% of lysosomal β-hexosaminidase. But when cells pretreated with vacuolin-1, releases no more β-hexosaminidase compared with cells that are not exposed to ionomycin (4%).
Cells were pretreated with 3 uM Eltrombopag, 1 uM vacuolin-1 (KKLMED),and 3 uM ML-SI3 (KKL MED) for 1 h, respectively[1].
Furthermore, it was observed that blockinglysosomal exocytosis with vacuolin-116 signiffcantlyprevented the expulsion of RSNs, conffrming therole of lysosomal exocytosis in this process (Figure 2G)[1].
Furtherexperiments with TRPML124 and TFEB9 inhibitors showed that both could effectively inhibit lysosomal exocytosis induced by RSNs (Figures 3G)[1].
P38 and P65, key proteins in the inflammatory signaling pathways,29 were found tobe significantly phosphorylated in the colon and rectum,indicating activation of the inflammatory signaling pathwa (Figure 4D)[1].

