Journal: bioRxiv
Article Title: A live-cell autophagy reporter reveals reversible vacuolation in naked mole-rat skin fibroblasts under lysosomal stress
doi: 10.64898/2026.03.18.712644
Figure Lengend Snippet: Western blot validation of mCherry–EGFP–LC3 NMR stable over-expression in NMR skin fibroblast lines. Cell lysates from single-cell–derived colonies were probed with antibodies against LC3 ( A ) and EGFP ( B ). Both antibodies detected doublet bands at approximately 80–82 kDa, consistent with the predicted molecular mass of the mCherry–EGFP–LC3 NMR fusion protein in the non-lipidated (LC3-I; top band) and lipidated (LC3-II, bottom band) forms. Markers are shown in lane M and individual colonies are labelled C1-C6. C ) mTOR inhibition by PP242 enhances autophagic flux in NMR skin fibroblasts. Representative live-cell confocal images of mCherry–EGFP–LC3 NMR expressing cells, either untreated or treated with PP242 (2 μM or 4 μM) for 24 h. PP242 treatment induces a shift from the appearance of autophagosomes (mCherry⁺/EGFP⁺ (yellow)) to autolysosomes (mCherry⁺/EGFP⁻ (red)). Scale bar is 10 μm. D) Bafilomycin A1 (Baf A1) impairs autophagic flux in NMR skin fibroblasts. Representative live-cell confocal images of mCherry–EGFP–LC3 NMR expressing cells, either untreated or treated with Baf A1 (166 nM, 250 nM, or 333 nM) for 24 h. Baf A1 treatment results in accumulation of mCherry⁺/EGFP⁺ (yellow) puncta, consistent with impaired autophagic flux. In C) and D) the nucleus is stained with Hoescht (blue).
Article Snippet: Site-directed mutagenesis was used to change three amino acids in the mammalian cell reporter plasmid expressing mCherry–EGFP–LC3 (Addgene #123230) to create the NMR version of LC3 (E105G, M121R, K122G) (mCherry–EGFP–LC3 NMR ).
Techniques: Western Blot, Biomarker Discovery, Over Expression, Single Cell, Derivative Assay, Inhibition, Expressing, Staining