Figure 1
From: REG3β modifies cell tumor function by impairing extracellular vesicle uptake
REG3β inhibits the uptake of EVs both in vitro and in vivo. (a) Transmission electron microscopy images of 120,000 × g pelleted THP1-EVs and MPC-EVs. 2x magnification in the lower right corner to appreciate the double membrane. Scale bars: 200 nm. (b) Representative Western blot of EVs samples and cell lysates to confirm the presence of classical exosome markers (CD81, ALIX, TSG101) and the absence of endoplasmic reticulum contamination (Calnexin). (c,d) Fluorescence microscopy of THP-1 macrophages (c) and MIA PaCa-2 cells (MPC) (d) incubated, respectively, with 3 µg/ml of PKH26-labeled MPC EVs or THP1-EVs and increasing concentrations of REG3β. Nuclei counterstained with DAPI. On the right, quantification of the amount of EVs internalization via fluorimetric reading (n = 4). Data are expressed as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, compared to 0 ng/ml REG3β. ANOVA with Tukey’s post-test was used to calculate P-values. Scale bars: 50 µm. (e) PKH26-labeled EVs injected into tumor xenografts were uptaken by tumor cells (−REG3β) but remained in the intercellular space when pretreated with REG3β (+REG3β). Nuclei counterstained with DAPI. 4x magnification in the top right corner. Scale bars: 50 µm.
