Secreted midbody remnants are a class of extracellular vesicles molecularly distinct from exosomes and microparticles

摘要

a Immunofluorescence microscopy analysis of SW620 cells using anti-MKLP1 antibodies. SW620 cells cultured on glass coverslips were stained with annexin-V. Midbodies (MB) between prospective daughter cells do not stain with annexin-V (top panel). In contrast, midbody remnants (MB-R) associated with one of the cells stained with annexin V (middle panel). MB-Rs are also detected extracellularly as shed midbody remnants (sMB-Rs) (bottom panel). Inset panels represent enlarged images of sMB-Rs. Scale bar, 10 µm. b Immunofluorescence microscopy analysis of SW620-GAP-GFP cells using anti-MKLP1 antibodies. Nuclei (blue) were stained with Hoechst stain. Inset: higher magnification of GFP-tagged sMB-Rs in the extracellular space. Scale bar, 10 µm. c Immunofluorescence microscopy analysis of SW620, SW480 and SW1222 cells cultured in MatrigelTM matrix using anti-MKLP1 antibodies (green) and Alexa Fluor 594 Phalloidin (red) to stain actin. Nuclei (blue) were stained with Hoechst stain. White arrow heads point show sMB-Rs. Scale bar, 10 µm. d Immunohistochemistry analysis of normal human colon tissue and colon cancer tissue (adenocarcinoma) using anti-MKLP1 and anti-RACGAP1 antibodies. Red arrows indicate anti-MKLP1 or anti-RACGAP1 staining extracellular sMB-Rs. Images obtained from Human Protein Atlas (http://www.proteinatlas.org/) with permission.