RRC ID 82815
Author Fujiwara K, Inoue T, Kimoto A, Zixian J, Tokuhiro K, Yasukochi Y, Akama TO, Cai CL, Shiojima I, Kimura H, Yoshimura SH, Nakamura T, Hirai M.
Title Spatial organizations of heterochromatin underpin nuclear structural integrity of ventricular cardiomyocytes against mechanical stress.
Journal Cell Rep
Abstract Cardiomyocyte (CM) nuclei are constantly exposed to mechanical stress, but how they maintain their nuclear shape remains unknown. In this study, we found that ventricular CM nuclei acquire characteristic prominent spatial organizations of heterochromatin (SOH), which are disrupted by high-level expression of H2B-mCherry in mice. SOH disruption was associated with nuclear softening, leading to extreme elongation and rupture under unidirectional mechanical stress. Loosened chromatin then leaks into the cytosol, causing severe inflammation and cardiac dysfunction. Although SOH disruption was accompanied by loosened higher-order genomic structures, the change in gene expression before nuclear deformation was mild, suggesting that SOH play major roles in nuclear structural integrity. Aged CM nuclei consistently exhibited scattered SOH and marked elongation. Furthermore, we provide mechanistic insight into the development and maintenance of SOH driven by chromatin compaction and condensate formation. These results highlight SOH as a safeguard of nuclear shape and genomic integrity against mechanical stress.
Volume 43(12)
Pages 115048
Published 2024-12-24
DOI 10.1016/j.celrep.2024.115048
PII S2211-1247(24)01399-8
PMID 39656588
MeSH Animals Cell Nucleus* / metabolism Heart Ventricles / metabolism Heart Ventricles / pathology Heterochromatin* / metabolism Male Mice Mice, Inbred C57BL Myocytes, Cardiac* / metabolism Stress, Mechanical*
IF 8.109
Resource
Mice RBRC06036