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: We used AAVpro 293T cells (TaKaRa, 632273) for MyoAAV production and BJ-5ta cells (human hTERT-immortalized foreskin fibroblast; ATCC, CRL-4001) for ChIP-seq spike-in controls.

Techniques: Immunofluorescence, Cell Culture, Isolation, Incubation, ChIP-sequencing, Comparison, Gene Expression, RNA Sequencing

Journal: bioRxiv

Article Title: RNA polymerase loss by nuclear rupture drives LMNA cardiomyopathy

doi: 10.64898/2026.04.03.716433

Figure Lengend Snippet: A) Number of Pol II ChIP-seq and input sequencing reads aligned to the mouse genome (experimental) or the human genome (spike-in control). Scale factors are computed by spike-in control reads and sequencing depths and used to normalize Pol II ChIP-seq signals. All data in are derived from mice at 2 weeks post tamoxifen. B) Pol II ChIP-seq read coverage in all mouse genes stratified by gene-body Pol II coverage. Genes with Pol II coverage greater than or equal to 100 (2 in Log 10 ) were considered Pol II-bound (11,942 genes). C) Pol II ChIP-seq read coverage in all human genes, derived from the spike-in control chromatin. D) Gene-body Pol II ChIP-seq read coverage between every pair of biological replicates. E) Principal Component Analysis (PCA) of gene-body Pol II coverage in 11,942 Pol II-bound protein-coding genes. F) Cumulative fraction of 1,759 Pol II-lost genes and all other genes (y-axis) along the scale of differential gene expression between Lmna CKO hearts and wild-type hearts (x-axis). P, Kolmogorov-Smirnov test p -value comparing log 2 fold change of gene expression between Pol II-lost genes and all other genes. G) Gene expression state of Pol II-lost genes, Pol II-gained genes, and all other genes in the cardiomyocyte population in Lmna CKO (n=3) versus WT (n=3) hearts derived from single-nucleus RNA-seq in En et al. 2024. P, DESeq2 p -value. H) Same as F, but along the scale of differential gene expression between Lmna CKO and wild-type pseudo-bulk cardiomyocytes from the single-nucleus RNA-seq. P, Kolmogorov-Smirnov test p -value comparing log 2 fold change of gene expression between Pol II-lost genes and all other genes.

Article Snippet: We used AAVpro 293T cells (TaKaRa, 632273) for MyoAAV production and BJ-5ta cells (human hTERT-immortalized foreskin fibroblast; ATCC, CRL-4001) for ChIP-seq spike-in controls.

Techniques: ChIP-sequencing, Sequencing, Control, Derivative Assay, Gene Expression, RNA Sequencing