Journal: Journal of Inflammation Research

Article Title: Protective Effects of CR6-Interacting Factor 1 Against Angiotensin II-Induced Atrial Fibrillation by Regulating the SIRT1/eNOS Signaling Pathway and Cardiomyocyte Remodeling

doi: 10.2147/JIR.S596132

Figure Lengend Snippet: CRIF1 was downregulated in the AF mice. ( A ) Atrial tissue of mice was stained with hematoxylin and eosin (H&E) to display the morphological structure. CRIF1 expression in the atrial tissue of mice was detected using immunohistochemistry (200×). ( B ) The CRIF1 mRNA levels in the atrial tissue were detected by RT-qPCR. The mice cardiac muscle cell line HL-1 was treated with Ang II (0, 0.1, 0.2, 0.5, 1 and 2 μM) for 24 h. ( C ) The CRIF1 mRNA expression was determined by RT-qPCR. Data are presented as mean ± SD (n=8 mice in each group). t -test was applied. ***P<0.001 vs control group.

Article Snippet: The mouse cardiac muscle cell line HL-1 was purchased from Procell (CL-0605, China).

Techniques: Staining, Expressing, Immunohistochemistry, Quantitative RT-PCR, Control

Journal: Journal of Inflammation Research

Article Title: Protective Effects of CR6-Interacting Factor 1 Against Angiotensin II-Induced Atrial Fibrillation by Regulating the SIRT1/eNOS Signaling Pathway and Cardiomyocyte Remodeling

doi: 10.2147/JIR.S596132

Figure Lengend Snippet: Overexpression of CRIF1 activates the SIRT1/eNOS pathway in cardiomyocytes treated with Ang II. HL-1 cells were transfected with pcDNA3.1-CRIF1 (OE-CRIF1) or vector for 24 h, and then treated with Ang II (1 μM) for an additional 24 h. The mRNA expression levels of ( A ) CRIF1, ( B ) SIRT1 and ( C ) eNOS were evaluated using RT-qPCR. HL-1 cells were transfected with pcDNA3.1-CRIF1 (OE-CRIF1) or vector for 24 h, and were then cotreated with a SIRT1 inhibitor EX527 (10 μM) and Ang II (1 μM) for further 24 h. ( D ) The cell apoptosis was assessed by staining with TUNEL and DAPI, and observed under a fluorescence microscope (200 X). ( E ) Apoptosis was quantified by calculating TUNEL positive cells (normalized to DAPI-stained cells). Data are presented as mean ± SD in triplicates. ***P<0.001 vs control group; ### P<0.001 vs Ang II+Vector group; $$$ P<0.001 vs OE-CRIF1 group.

Article Snippet: The mouse cardiac muscle cell line HL-1 was purchased from Procell (CL-0605, China).

Techniques: Over Expression, Transfection, Plasmid Preparation, Expressing, Quantitative RT-PCR, Staining, TUNEL Assay, Fluorescence, Microscopy, Control

Journal: Journal of Inflammation Research

Article Title: Protective Effects of CR6-Interacting Factor 1 Against Angiotensin II-Induced Atrial Fibrillation by Regulating the SIRT1/eNOS Signaling Pathway and Cardiomyocyte Remodeling

doi: 10.2147/JIR.S596132

Figure Lengend Snippet: CRIF1 overexpression inhibits Ang II–induced hypertrophy of HL-1 cells. ( A ) Cells were stained with α-actinin antibody and observed under a fluorescence microscope. Representative images are shown (200×). RT-qPCR was used to assess the mRNA expression levels of hypertrophy-related genes, including ( B ) ANP, ( C ) BNP, and ( D ) β-MHC. Data are presented as mean ± SD in triplicate. ***P<0.001 vs control group; ### P<0.001 vs Ang II+Vector group; $$$ P<0.001 vs OE-CRIF1 group.

Article Snippet: The mouse cardiac muscle cell line HL-1 was purchased from Procell (CL-0605, China).

Techniques: Over Expression, Staining, Fluorescence, Microscopy, Quantitative RT-PCR, Expressing, Control, Plasmid Preparation

Journal: Journal of Inflammation Research

Article Title: Protective Effects of CR6-Interacting Factor 1 Against Angiotensin II-Induced Atrial Fibrillation by Regulating the SIRT1/eNOS Signaling Pathway and Cardiomyocyte Remodeling

doi: 10.2147/JIR.S596132

Figure Lengend Snippet: CRIF1 overexpression suppresses Ang II–induced inflammation in cardiomyocytes. ( A – C ) RT-qPCR was used to determine the mRNA levels of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6. ( D – F ) ELISA was used to measure the levels of TNF-α, IL-1β, and IL-6 in the culture medium of HL-1 cells. Data are presented as mean ± SD in triplicate. ***P<0.001 vs control group; ### P<0.001 vs Ang II+Vector group; $$$ P<0.001 vs OE-CRIF1 group.

Article Snippet: The mouse cardiac muscle cell line HL-1 was purchased from Procell (CL-0605, China).

Techniques: Over Expression, Quantitative RT-PCR, Enzyme-linked Immunosorbent Assay, Control, Plasmid Preparation

Journal: Journal of Inflammation Research

Article Title: Protective Effects of CR6-Interacting Factor 1 Against Angiotensin II-Induced Atrial Fibrillation by Regulating the SIRT1/eNOS Signaling Pathway and Cardiomyocyte Remodeling

doi: 10.2147/JIR.S596132

Figure Lengend Snippet: Overexpression of CRIF1 inhibits intracellular ROS generation and oxidative stress in cardiomyocytes treated with Ang II. ( A ) Cells were stained with DHE, and representative images of intracellular ROS are shown (200×). ( B ) The extent of intracellular ROS was quantified by counting DHE-positive cells (normalized to DAPI-stained cells). Cell lysates of HL-1 cells were used to detect the oxidative stress markers: ( C ) MDA, ( D ) SOD, ( E ) CAT, and ( F ) NO. Data are presented as mean ± SD in triplicate. ***P<0.001 vs control group; ### P<0.001 vs Ang II+Vector group; $$$ P<0.001 vs OE-CRIF1 group.

Article Snippet: The mouse cardiac muscle cell line HL-1 was purchased from Procell (CL-0605, China).

Techniques: Over Expression, Staining, Control, Plasmid Preparation

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A) Mating strategy to create lamin-A and -B1 genotypes. (B,C) Representative immunofluorescence images of cultured E13.5 cardiomyocytes stained for lamin-A (B) or lamin-B1 (C) (magenta) with DAPI (cyan), showing efficient Nkx2-5Cre-mediated depletion. Scale bar, 10 μm. (D,E) Quantification of lamin-A (D) and lamin-B1 (E) fluorescence intensity, demonstrating >90% depletion in knockout E13.5 cardiomyocytes (mean ± SD; n = 3 embryos per genotype). (F) Kaplan-Meier survival analysis of cardiomyocyte-specific lamin mutants. Double knockout (Lmna -/- ; Lmnb1 -/- ) mice exhibit perinatal lethality (∼P1), whereas mice retaining a single allele of lamin-A or lamin-B1 ( Lmna +/- ; Lmnb1 -/- or Lmna -/- ; Lmnb1 +/- ) survive until P7-P14; Lmnb1 -/- mice are viable. Statistical significance was determined by log-rank (Mantel-Cox) test (****P < 0.0001).

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Immunofluorescence, Cell Culture, Staining, Fluorescence, Knock-Out, Double Knockout

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A, B) Representative confocal images of cultured E13.5 cardiomyocyte nuclei immunostained for either the NPC marker TPR (A, magenta) or the LINC complex component Sun1 (B, magenta) and counterstained with DAPI (cyan) across the indicated genotypes. Scale bar, 20 μm. (C) Schematic illustrating quantification of nuclear fluorescence distribution. Each nucleus was divided into ten equal sections along the polarization axis (0.1–1.0), from highest to lowest signal. Mean fluorescence was calculated per section and normalized to the maximum value within each nucleus, with 1.0 representing peak intensity. (D,E,G) Quantification of the normalized fluorescence intensity distribution for TPR (D), Sun1 (E), and DAPI (G). Mean ± SD; n = 3 biological replicates per genotype and stain (F) Representative confocal images of DAPI-stained nuclei in cultured E13.5 cardiomyocytes of the indicated genotypes. Scale bar as indicated.

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Cell Culture, Marker, Fluorescence, Staining

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A,B) Representative confocal images of cultured E13.5 cardiomyocytes immunostained for α-tubulin (α-tub, white), DAPI (cyan), and either the NPC marker TPR (magenta) (A) or the LINC complex component Sun1 (magenta) (B) across the indicated genotypes. Scale bar, 10 μm. (C) Stacked bar plot showing quantification of microtubule organization categories in E13.5 cardiomyocytes across the indicated genotypes. Bars represent the percentage of cardiomyocytes displaying each microtubule phenotype: strong perinuclear ring (black), strong ring with polarized NPCs/LINC complexes (blue), astral array with no strong ring (yellow), or polarized astral array (green). Data represents mean and n= 3 biological replicates.

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Cell Culture, Marker

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A,E) Representative confocal images of cultured E13.5 (A) and P0.5 (E) cardiomyocyte nuclei immunostained for γH2AX (magenta) and counterstained with DAPI (cyan) across the indicated genotypes. Scale bar, 20 μm. (B) Mean and SD plot showing quantification of nuclear roundness scores in E13.5 cardiomyocytes across the indicated genotypes. Each dot represents one biological replicate with cells averaged per replicate. Mean ± SD; n = 3 biological replicates per genotype (Student’s t-test; *p < 0.05, **p < 0.01, ***p < 0.001). (C) Quantification of average γH2AX fluorescence intensity per nucleus in E13.5 cardiomyocytes across the indicated genotypes. Each dot represents one biological replicate with cells averaged per replicate. Mean ± SD; n = 3 biological replicates per genotype. No statistically significant differences were detected between genotypes (Student’s t-test). (D) Quantification of γH2AX positive cells per nucleus in P0.5 heart sections across the indicated genotypes. Mean ± SD; n = 3 biological replicates per genotype. (Student’s t-test; *p < 0.05, **p < 0.01).

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Cell Culture, Fluorescence

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A,D) Representative confocal images of cultured E13.5 cardiomyocytes (A) and disrupted P7.5 tissue sections (D) immunostained for cardiac troponin T (cTnT, green) and Ryanodine Receptor 2 (Ryr2, magenta) in Lmnb1 +/- and Lmnb1 -/- cardiomyocytes. Scale bars are as indicated. N = 3 biological replicates per genotype and timepoint. (B) Table summarizing the identity of 13 ventricular cardiomyocyte clusters identified by scRNA-seq. (C) UMAP of all ventricular cardiomyocytes from the integrated public and P0.5 datasets, colored by cluster identity. (E, F, H, I) UMAPs showing the distribution of ventricular cardiomyocytes from the public E13.5 (E) and P1 (F) datasets and P0.5 Lmnb1 +/- (H) and Lmnb1 -/- (I) datasets (teal), projected onto the integrated UMAP combining public datasets and Lmnb1 +/- and Lmnb1 -/- datasets, with all other cells shown in gray. (G) Volcano plot of differentially expressed genes in compact ventricular cardiomyocytes from Lmnb1 -/- versus Lmnb1 +/- hearts. Downregulated genes and upregulated genes are shown in blue and red, respectively. The dashed lines indicate significance thresholds (|Log 2 FC| > 0.26; p < 0.05). Differential gene expression analysis was restricted to genes expressed in more than 25% of cells in at least one genotype. (J, K) Selected GO-terms enriched among downregulated (J) and upregulated (K) genes in Lmnb1 -/- compact ventricular cardiomyocytes.

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Cell Culture, Gene Expression

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A) UMAPs of the integrated scRNA-seq dataset showing major cardiac cell populations, displayed separately for public data (left), Lmnb1 +/- (middle), and Lmnb1 -/- (right) datasets. Major cell populations are denoted, including ventricular cardiomyocytes, atrial cardiomyocytes, fibroblast-like cells, epicardial cells, endocardial/epithelial cells, vascular epithelial cells, blood cells, and immune cells. (B) Heatmap showing scaled expression (z-score) of top marker genes across five compact ventricular cardiomyocyte clusters (clusters 0, 1, 2, 3, and 8), used to assign developmental stage identities. (C) UMAP of ventricular cardiomyocytes colored by cell cycle phase (G1, red; G2M, green; S, blue) inferred with Seurat’s CellCycleScoring package. (D, E) Stacked bar plots showing the percentage of ventricular cardiomyocytes from each cluster in the public E13.5 and P1 datasets (D) or Lmnb1 +/- and Lmnb1 -/- P0.5 datasets (E).

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Expressing, Marker

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A) Genome browser tracks showing LADs mapping with lamin-A CUT&RUN z-score signal and HMM-defined LAD calls (black bars) for a representative region of chromosome 3 in Lmnb1 +/- (top) and Lmnb1 -/- (bottom) P0.5 cardiomyocytes. Example regions of LAD loss are highlighted in purple. (B) Venn diagram showing the proportion of genome coverage of LADs shared between Lmnb1 +/- and Lmnb1 -/- cardiomyocytes, LADs unique to Lmnb1 +/- , and LADs unique to Lmnb1 -/- . (C) Violin plots showing the size distribution (log scale) of LADs undergoing complete loss versus loss at edges in Lmnb1 -/- cardiomyocytes. Box plots within violins indicate median and interquartile range. (D) ICE-normalized Hi-C contact maps for a representative region of chromosome 10 in Lmnb1 +/- (left) and Lmnb1 -/- (right) P0.5 cardiomyocytes at 10 kb resolution. Color scale represents normalized contact frequency. (E) Interchromosomal interaction matrix showing the percent change in inter-chromosomal contacts in Lmnb1 -/- relative to Lmnb1 +/- cardiomyocytes. (F) Representative fluorescence in situ hybridization (FISH) images of chromosome 1 (Chr1, green, left) and chromosome 13 (Chr13, green, right) counterstained with DAPI (gray) in Lmnb1 +/- and Lmnb1 -/- cardiomyocytes at E13.5. Scale bar, 10 μm. (G) Quantification of cumulative chromosome volume (µm 3 ) for Chr1 and Chr13 in Lmnb1 +/- and Lmnb1 -/- Quantification of cumulative chromosome volume (µm3) for Chr1 and Chr13 in Lmnb1+/- and Lmnb1-/- E13.5 cardiomyocytes. Each dot represents one biological replicate with cells averaged per replicate. Mean ± SD; n ≥ 4 biological replicates per genotype (Student’s t-test; *p < 0.05, **p < 0.01). (H) Representative FISH images of Chr1 (green) counterstained with DAPI (gray) in Lmnb1 +/- and Lmnb1 -/- P7.5 cardiomyocytes. Scale bar, 10 μm.

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Hi-C, Fluorescence, In Situ Hybridization

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A) Normalized contact frequency as a function of genomic distance for all Hi-C replicates, showing high consistency between Lmnb1 +/- replicates (dark/light blue) and Lmnb1 -/- replicates (red/orange). (B) Whole-genome correlation between biological replicates across increasing Hi-C resolutions (50–500 kb) for Lmnb1 +/- (pink) and Lmnb1 -/- (teal) samples. (C) Venn diagram showing the number of TAD boundaries shared between and unique to Lmnb1 +/- and Lmnb1 -/- cardiomyocytes. (D) Genome browser tracks showing C-scores and LADs mapping of lamin-A CUT&RUN z-score signal with HMM-defined LAD calls for a representative region of chromosome 3 in Lmnb1 +/- (top) and Lmnb1 -/- (bottom) cardiomyocytes. Positive C-scores indicate B-compartment and negative C-scores indicate A compartment regions. (E) Heatmaps showing insulation scores in ±500 kb around TAD boundaries at 20 kb resolution in Lmnb1 +/- and Lmnb1 -/- P0.5 cardiomyocytes. Groups I, II, and III correspond to TAD boundaries shared between genotypes, unique to Lmnb1 +/- , and unique to Lmnb1 -/- , respectively, as defined in (C). (F) Density scatter plot showing the correlation between lamin-A CUT&RUN z-score signal and C-score across the genome, with color indicating point density. (G) Box plot showing the genome-wide change in C-score ( Lmnb1 -/- - Lmnb1 +/- ) across all genomic bins. (***p < 0.001, Wilcoxon rank-sum test). (H) Box plot showing the change in C-score ( Lmnb1 -/- - Lmnb1 +/- ) restricted to regions of LAD loss. (***p < 0.001, Wilcoxon rank-sum test).

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Hi-C, Insulation, Genome Wide

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A) Heatmap showing the mean z-score of lamin-A CUT&RUN LADs mapping, ATAC-seq, and epigenomic features across the six HiLands states defined in wild-type and Lmnb1 +/- P0.5 cardiomyocytes. (B) Genome browser tracks showing LADs mapping, ATAC-seq and histone modification signals alongside a representative region of chromosome 8 in wild-type and Lmnb1 +/- P0.5 cardiomyocytes. HiLands state annotation is shown at the top. (C) Matrix showing the change in chromatin interactions between pairs of HiLands states in Lmnb1 -/- relative to Lmnb1 +/- P0.5 cardiomyocytes. Values represent Log 2 FC × 100. (D) Box plots showing the Log 2 FC of lamin-A CUT&RUN z-score signal within HiLands-P and HiLands-B regions in Lmnb1 -/- relative to Lmnb1 +/- cardiomyocytes. Box plots depict median and interquartile range. (***p < 0.001, Wilcoxon rank-sum test). (E) Box plots showing the genome-wide C-score change ( Lmnb1 -/- - Lmnb1 +/- ) within HiLands-P and HiLands-B regions. Box plots depict median and interquartile range. (***p < 0.001, Wilcoxon rank-sum test). (F) Pie charts showing the distribution of HiLands states among the promoters of upregulated (top) and downregulated (bottom) genes in Lmnb1 -/- compact ventricular cardiomyocytes. (G) Heatmaps showing the mean Log 2 FC in 3D chromatin interactions between promoters of upregulated and downregulated genes and each HiLands state within ±5 Mb of individual promoters in Lmnb1 -/- relative to Lmnb1 +/- cardiomyocytes. Upregulated gene promoters show significantly reduced interactions with HiLands-B (p = 0.01), -G (p = 0.02), and -O (p = 0.047) compared to non-dysregulated genes. Downregulated gene promoters show significantly increased interactions with HiLands-P (p = 0.0002), -B (p = 0.003), and -Y (p = 0.003) compared to non-dysregulated genes (Wilcoxon rank-sum test). (H) Schematic model of chromatin neighborhood disruption following lamin-B1 loss. In Lmnb1 +/- cardiomyocytes (left), Gene A associates with active HiLands states and is expressed, while Gene B associates with repressive HiLands states and is silenced. In Lmnb1 -/- cardiomyocytes (right), LAD detachment and chromosome expansion alter chromatin neighborhoods, causing Gene A to gain repressive contacts and become silenced, while Gene B loses repressive contacts and becomes expressed.

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Modification, Genome Wide, Disruption

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A) Pie chart showing the genome composition by HiLands state in wild-type P0.5 cardiomyocytes. Percentages indicate the fraction of the genome occupied by each state. (B) Box plots showing LADs mapping with lamin-A CUT&RUN z-score signal of bins across each HiLands state. (C) Pie chart showing the distribution of ATAC-seq peaks across HiLands states, with HiLands-Y, -O, and -R containing the majority of accessible chromatin regions. (D) Bar plot showing promoter density (promoters per Mb) across HiLands states. (E) Pie chart showing the overall distribution of gene promoters across HiLands states. (F) Box plots showing gene expression levels (log10 TPM) across HiLands states in P0.5 Lmnb1 +/- compact cardiomyocytes from scRNA-seq data. (G) Box plots showing the C-score for each HiLands state bin in P0.5 cardiomyocytes.

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Gene Expression

Journal: bioRxiv

Article Title: Lamin dosage in cardiomyocytes supports nuclear organization and chromatin gating for transcription

doi: 10.64898/2026.05.20.726565

Figure Lengend Snippet: (A,B) The top five enriched transcription factor binding motifs identified by HOMER analysis at promoters of downregulated (A) and upregulated (B) genes in Lmnb1 -/- compact ventricular cardiomyocytes. (C, D) Hi-C contact maps (10 kb resolution, dynamic binning; see Methods) showing Log 2 fold changes in chromatin interactions in Lmnb1 -/- relative to Lmnb1 +/- cardiomyocytes at the Jun locus on chromosome 4 (C) and the Cdk4 locus on chromosome 10 (D). HiLands annotations are shown along the diagonal, with loci indicated by cyan lines. Pseudo-4C Log 2 FC tracks above each map highlight locus-specific contact changes, and black lines indicate TAD boundaries. (E, F) Genome browser tracks at the Jun locus (E) and Cdk4 (F) locus showing H3K4me3, Sp1 (for Jun and Cdk4), Banp (for Jun), and Mef2d (for Jun) binding motif positions, CPM-normalized scRNA-seq signal from Lmnb1 +/- and Lmnb1 -/- compact ventricular cardiomyocytes, and gene annotation. The HiLands states are shown at the top. (G) Schematic model illustrating how lamin-B1 loss alters transcription factor binding environments. In Lmnb1 +/- cardiomyocytes (left), cardiomyocyte maturation transcription factor binding motifs (black circles) associate with active chromatin regions, while cell cycle/early developmental motifs (black diamonds) associate with repressive chromatin regions, promoting cardiomyocyte maturation. In Lmnb1 -/- cardiomyocytes (right), chromatin neighborhood shifts reduce maturation-associated motif availability to transcription factors and increase access to motifs linked to cell cycle and immature gene programs, impairing maturation.

Article Snippet: The cells were then incubated with neonatal cardiomyocyte isolation magnetic beads (Miltenyi Biotec, 130-100-825) for 15 minutes while rotating at 4°C in the dark; these beads bind non-cardiomyocyte populations.

Techniques: Binding Assay, Hi-C