Journal: bioRxiv
Article Title: RNA polymerase loss by nuclear rupture drives LMNA cardiomyopathy
doi: 10.64898/2026.04.03.716433
Figure Lengend Snippet: A) Immunofluorescence for bromouridine (BrU) after cardiomyocytes were cultured with BrU for 2 hr to label nascent RNAs. One binucleated cardiomyocyte per image, with nuclei zoomed in. Texts and icons below images indicate nuclear states. Scale bar: 5 μm. All data in , except , are from cardiomyocytes freshly isolated from mice at day 14 post tamoxifen. B) Nuclear BrU intensity by nuclear states after 1-hr BrU incubation. Density and box plots: BrU intensity distribution and interquartile range. Circles: mean intensity within biological replicates (color coded). Asterisks: P < 0.05 from t -tests on linear regression-estimated means with mouse-clustered standard errors. Underlying data: 244 intact nuclei from 4 WT mice, 275 intact, 111 ruptured, 104 resealed nuclei from 3 Lmna CKO mice. C) Relationship between nuclear BrU intensity and nuclear NLS–tdTomato intensity in all types of nuclei in Lmna CKO cardiomyocytes (519 nuclei from 3 mice). Line: simple linear regression fit with 95% confidence interval. R: Pearson correlation coefficient. P: t -test p -value on linear regression-estimated means with mouse-clustered standard errors. See for individual replicates. D) Immunofluorescence for RNA polymerase II (Pol II) in cardiomyocytes. Scale bar: 5 μm. E) Nuclear Pol II intensity by nuclear states. Underlying data: 285 intact nuclei from 3 WT mice, 180 intact, 133 ruptured, 136 resealed nuclei from 3 Lmna CKO mice. Graph annotations and statistics as in (B) . F) Relationship between Pol II intensity and NLS–tdTomato intensity in all types of nuclei in Lmna CKO cardiomyocytes (495 nuclei from 3 mice). Graph annotations and statistics as in (C) . G) Pol II ChIP-seq and input read coverage in WT and Lmna CKO cardiomyocytes (3 mice per genotype). ChIP-seq signals are normalized to internal spike-in controls. H) Average Pol II ChIP-seq signals across 21,177 protein-coding genes. X-axis: 100 equally-spaced bins in gene bodies, 5 bins for 1 kb-upstream regions, and 10 bins for 2 kb-downstream regions. I) Statistical comparison of gene-body Pol II signals in Lmna CKO versus WT cardiomyocytes for 11,942 Pol II-bound genes. Pol II-lost or gained genes are defined at limma p -value < 0.05. J) Ten most enriched Gene Ontology terms among the 1,759 Pol II-lost genes in Lmna CKO cardiomyocytes, with three representative genes for each term. P: Metascape p -value. K) Gene expression state of Pol II-lost, Pol II-gained, and all other genes in Lmna CKO (n=5) versus WT (n=7) hearts. P, DESeq2 p -value. RNA-seq data from En et al. 2024. L) Summary of . Nuclear rupture causes transcriptional deficiency due to RNA Pol II loss.
Article Snippet: Lysates were incubated with rabbit anti-Pol II NTD antibody (Cell Signaling Technology, #14958) overnight at 4 °C.
Techniques: Immunofluorescence, Cell Culture, Isolation, Incubation, ChIP-sequencing, Comparison, Gene Expression, RNA Sequencing