Sensitive detection of lysosomal membrane permeabilization by lysosomal galectin puncta assay

Research output: Contribution to journalArticle

Abstract

Lysosomal membrane permeabilization (LMP) contributes to tissue involution, degenerative diseases, and cancer therapy. Its investigation has, however, been hindered by the lack of sensitive methods. Here, we characterize and validate the detection of galectin puncta at leaky lysosomes as a highly sensitive and easily manageable assay for LMP. LGALS1/galectin-1 and LGALS3/ galectin-3 are best suited for this purpose due to their widespread expression, rapid translocation to leaky lysosomes and availability of high-affinity antibodies. Galectin staining marks individual leaky lysosomes early during lysosomal cell death and is useful when defining whether LMP is a primary or secondary cause of cell death. This sensitive method also reveals that cells can survive limited LMP and confirms a rapid formation of autophagic structures at the site of galectin puncta. Importantly, galectin staining detects individual leaky lysosomes also in paraffin-embedded tissues allowing us to demonstrate LMP in tumor xenografts in mice treated with cationic amphiphilic drugs and to identify a subpopulation of lysosomes that initiates LMP in involuting mouse mammary gland. The use of ectopic fluorescent galectins renders the galectin puncta assay suitable for automated screening and visualization of LMP in live cells and animals. Thus, the lysosomal galectin puncta assay opens up new possibilities to study LMP in cell death and its role in other cellular processes such as autophagy, senescence, aging, and inflammation.

Details

Authors
  • Sonja Aits
  • Jennifer Kricker
  • Bin Liu
  • Anne Marie Ellegaard
  • Saara Hämälistö
  • Siri Tvingsholm
  • Elisabeth Corcelle-Termeau
  • Søren Høgh
  • Thomas Farkas
  • Anna Holm Jonassen
  • Irina Gromova
  • Monika Mortensen
  • Marja Jäättelä
External organisations
  • Danish Cancer Society Research Center
  • University of Iceland
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cell and Molecular Biology

Keywords

  • Breast involution, C. elegans, Cell death, Galectin, Lysosome
Original languageEnglish
Pages (from-to)1408-1424
JournalAutophagy
Volume11
Issue number8
Publication statusPublished - 2015 Jun 26
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes