Journal: bioRxiv
Article Title: Loss of Parkin Disrupts Nuclear and Mitochondrial Programs Required for Muscle Regeneration
doi: 10.64898/2026.03.20.712989
Figure Lengend Snippet: A) g:Profiler enrichment map illustrating nuclear processes downregulated in PARKIN deficient MuSCs compared to controls. The auto-annotation tool was used on Cytoscape to automatically generate cluster labels. B) Confocal image and 3D reconstruction of mitochondria (TOM20, green), nucleus (DAPI, blue) and PARKIN + foci (red) in freshly isolated and 24-48h in vitro activated MuSCs from wild type mice. PARKIN + foci located within the nuclear compartment is shown in Yellow in the right-end panels, where mitochondria and nuclear surfaces have been removed for clarity. C) Quantification of cytosolic PARKIN + foci in in situ fixed, freshly sorted quiescent and 24-48h in vitro activated MuSCs. PARKIN was defined as cytosolic if the overlap ratio between PARKIN + foci and nuclear volume ranged between 0 and 0.4. D) Quantification of nuclear PARKIN + foci in in situ fixed, freshly sorted quiescent and 24-48h in vitro activated MuSCs. PARKIN was defined as nuclear if the overlap ratio between PARKIN + foci and nuclear volume was above 0.8 ( n =10-36 cells from 4 mice per genotype and time point). In panel C and D, note the absence of PARKIN staining in MuSC Park2 -/- cells confirming the specificity of the staining. E) Quantification of Ubiquitin + foci within the nuclear compartment in MuSC Park2 +/+ and MuSC Park2 -/- MuSCs at 18hr into culture. ( n =24-32 cells from 3 mice per genotype) F) Confocal image and 3D reconstruction of K63-Ubiquitin + foci (red) and nucleus (DAPI blue) and nuclear ubiquitin (yellow) in 18hr cultured MuSCs. Ubiquitin signal was defined as nuclear if the overlap ratio between Ubiquitin + foci and nuclear volume was above 0.8. G) Confocal image and 3D reconstruction of PARKIN (red), SC35/SRRM2 + speckles (green) and nucleus (DAPI, blue) in freshly isolated wild-type MuSCs. H) Proportion of nuclear speckles labeled by PARKIN in freshly isolated wild type MuSCs. ( n =64 cells from 6 mice) I-J) Quantification of total speckle content per nucleus and volume of individual speckles in MuSC Park2 +/+ and MuSC Park2 -/- MuSCs. ( n = 23-24 cells from 3 mice per genotype). K) Confocal image and 3D reconstruction of speckles (SC35/SRRM2, green) and nucleus (DAPI, blue) in freshly isolated MuSC Park2 +/+ and MuSC Park2 -/- MuSCs. All data are presented as mean ± SEM. ns: not significant, *: p<0.05, **: p<0.01, ***: p<0.001, ****: p<0001 on unpaired two-tailed t tests or one-way ANOVAs comparing MuSC Park2 +/+ and MuSC Park2 -/- .
Article Snippet: Park2 loxP/loxP mice were obtained from Lexicon Pharmaceuticals and bred with Pax7CreERT2 GAKA mice obtained from Jackson’s laboratory ( B6.Cg-Pax7 tm1(cre/ERT2)Gaka /J ) to develop a Tamoxifen inducible and conditional knockout of PARKIN in PAX7 + adult MuSCs.
Techniques: Isolation, In Vitro, In Situ, Staining, Ubiquitin Proteomics, Cell Culture, Labeling, Two Tailed Test