Histone H3 Variant Research Articles

Single-cell and bulk RNA sequencing analysis reveals CENPA as a potential biomarker and therapeutic target in cancers.

Cancer remains one of the most significant public health challenges worldwide. A widely recognized hallmark of cancer is the ability to sustain proliferative signaling, which is closely tied to various cell cycle processes. Centromere Protein A (CENPA), a variant of the standard histone H3, is crucial for selective chromosome segregation during the cell cycle. Despite its importance, a comprehensive pan-cancer bioinformatic analysis of CENPA has not yet been conducted. Data on genomes, transcriptomes, and clinical information were retrieved from publicly accessible databases. We analyzed CENPA's genetic alterations, mRNA expression, functional enrichment, association with stemness, mutations, expression across cell populations and cellular locations, link to the cell cycle, impact on survival, and its relationship with the immune microenvironment. Additionally, a prognostic model for glioma patients was developed to demonstrate CENPA's potential as a biomarker. Furthermore, drugs targeting CENPA in cancer cells were identified and predicted using drug sensitivity correlations and protein-ligand docking. CENPA exhibited low levels of gene mutation across various cancers. It was found to be overexpressed in nearly all cancer types analyzed in TCGA, relative to normal controls, and was predominantly located in the nucleus of malignant cells. CENPA showed a strong association with the cancer cell cycle, particularly as a biomarker for the G2 phase. It also emerged as a valuable diagnostic and prognostic biomarker across multiple cancer types. In glioma, CENPA demonstrated reliable prognostic potential when used alongside other prognostic factors. Additionally, CENPA was linked to the immune microenvironment. Drugs such as CD-437, 3-Cl-AHPC, Trametinib, BI-2536, and GSK461364 were predicted to target CENPA in cancer cells. CENPA serves as a crucial biomarker for the cell cycle in cancers, offering both diagnostic and prognostic value.

Stable centromere association of the yeast histone variant Cse4 requires its essential N-terminal domain.

Chromosome segregation relies on kinetochores that assemble on specialized centromeric chromatin containing a histone H3 variant. In budding yeast, a single centromeric nucleosome containing Cse4 assembles at a sequence-defined 125 bp centromere. Yeast centromeric sequences are poor templates for nucleosome formation in vitro, suggesting the existence of mechanisms that specifically stabilize Cse4 nucleosomes in vivo. The extended Cse4 N-terminal tail binds to the chaperone Scm3, and a short essential region called END within the N-terminal tail binds the inner kinetochore complex Okp1/Ame1. To address the roles of these interactions, we utilized single-molecule fluorescence assays to monitor Cse4 during kinetochore assembly. We found that Okp1/Ame1 and Scm3 independently stabilize Cse4 at centromeres via their END interaction. Scm3and Cse4 stability at the centromere are enhanced by Ipl1/Aurora B phosphorylation of the Cse4 END, identifying a previously unknown role for Ipl1 in ensuring Cse4 stability. Strikingly, a phosphomimetic mutation in the Cse4 END restores Cse4 recruitment in mutants defective in Okp1/Ame1 binding. Together, these data suggest that a key function of the essential Cse4 N-terminus is to ensure Cse4 localization at centromeres.

Centromere inactivation during aging can be rescued in human cells.

Aging involves a range of genetic, epigenetic, and physiological alterations. A key characteristic of aged cells is the loss of global heterochromatin, accompanied by a reduction in canonical histone levels. In this study, we track the fate of centromeres in aged human fibroblasts and tissues and in various cellular senescent models. Our findings reveal that the centromeric histone H3 variant CENP-A is downregulated in aged cells in a p53-dependent manner. We observe repression of centromeric noncoding transcription through an epigenetic mechanism via recruitment of a lysine-specific demethylase 1 (LSD1/KDM1A) to centromeres. This suppression results in defective de novo CENP-A loading at aging centromeres. By dual inhibition of p53 and LSD1/KDM1A in aged cells, we mitigate the reduction in centromeric proteins and centromeric transcripts, leading to the mitotic rejuvenation of these cells. These results offer insights into a unique mechanism for centromeric inactivation during aging and provide potential strategies to reactivate centromeres.

A Linker Histone Acts as a Transcription Factor to Orchestrate Malic Acid Accumulation in Apple in Response to Sorbitol.

High carbohydrate availability promotes malic acid accumulation in fleshy fruits, but the underlying mechanism is not known. Here, we show that antisense repression of ALDOSE-6-PHOSPHATE REDUCTASE in apple (Malus domestica) decreases the concentrations of sorbitol and malate and the transcript levels of several genes involved in vacuolar malate transport, including the aluminum-activated malate transporter (ALMT) gene MdALMT9 (Ma1), the P-ATPase gene MdPH5, the MYB transcription factor gene MdMYB73, and the cold-induced basic helix-loop-helix transcription factor gene MdCIbHLH1, in fruit and leaves. We identified a linker histone H1 variant, MdH1.1, which complements the Arabidopsis (Arabidopsis thaliana) H1 deficient mutant and functions as a transcription factor. MdH1.1 activates MdMYB73, MdCIbHLH1, and MdPH5 expression by directly binding to their promoters. MdMYB73, in return, binds to the promoter of MdH1.1 to enhance its transcription. This MdH1.1-MdMYB73 feedback loop responds to sorbitol, regulating Ma1 expression. Antisense suppression of either MdH1.1 or MdMYB73 expression significantly decreases whereas overexpression increases Ma1 expression and malate accumulation. These findings demonstrate that MdH1.1, in addition to being an architectural protein for chromatin structure, operates as a transcription factor orchestrating malic acid accumulation in response to sorbitol, revealing how sugar signaling modulates vacuolar malate transport via a linker histone in plants.

Histone variant H3.5 in testicular cell differentiation and its interactions with histone chaperones

Testicular cell differentiation is a highly regulated process, essential for male reproductive health. The histone variant H3.5 is apparently a critical player in this intricate orchestra of cell types, but its regulation and function remains poorly understood. To elucidate its role, we fractionized testicular cells using c-Kit/CD117 as a separation marker and analyzed H3.5 expression. Further, we investigated the regulation of H3.5 expression using public data repositories. We explored DNA methylation patterns in specific regions of the H3-5 gene and assessed H3-5 copy number gain in seminoma specimens. Additionally, we examined the testicular localization of H3.5 and its histone chaperone interactions to understand its regulation at the protein level. We used qRT-PCR, MeDIP, and qPCR to study H3.5 expression and DNA methylation in various cell types. H3-5 copy number gain was analyzed using qPCR. Protein interactions were investigated through fluorescence-2-hybrid assays in baby hamster kidney cells. H3.5 is primarily enriched in spermatocytes. DNA methylation of a CpG island overlapping the H3-5 promoter appeared to be involved in the tissue-specific regulation of H3.5 expression. Elevated H3.5 expression was observed in seminoma specimens, suggesting a potential link to testicular tumors. H3-5 copy number gain was associated with elevated H3.5 expression in seminoma specimens. Furthermore, we identified physical interactions between H3.5 and histone chaperones Asf1a and Asf1b, HIRA, CAF p150 and DAXX, shedding light on the protein-level regulation of H3.5. These findings provide valuable insights into the molecular mechanisms governing testicular cell differentiation and the potential role of H3.5 in testicular pathologies.

Identification and annotation of centromeric hypomethylated regions with CDR-Finder.

Centromeres are chromosomal regions historically understudied with sequencing technologies due to their repetitive nature and short-read mapping limitations. However, recent improvements in long-read sequencing allow for the investigation of complex regions of the genome at the sequence and epigenetic levels. Here, we present Centromere Dip Region (CDR)-Finder: a tool to identify regions of hypomethylation within the centromeres of high-quality, contiguous genome assemblies. These regions are typically associated with a unique type of chromatin containing the histone H3 variant CENP-A, which marks the location of the kinetochore. CDR-Finder identifies the CDRs in large and short centromeres and generates a BED file indicating the location of the CDRs within the centromere. It also outputs a plot for visualization, validation, and downstream analysis. CDR-Finder is available at https://github.com/EichlerLab/CDR-Finder.

Defects in the H3t Gene Cause an Increase in Leydig Cells With Impaired Spermatogenesis in Mice.

Abnormalities in spermatogenesis, a fundamental component of male reproductive function, can cause male infertility. Somatic cells constituting the testis microenvironment are essential for controlling normal spermatogenesis. Although testicular somatic cells are thought to sense and respond to germ cells to ensure proper spermatogenesis, the details of this signaling mechanism are unknown. Here, we investigated somatic cell dynamics in testicular tissue lacking spermatogenesis using the mice with deletion of the testis-specific histone H3 variant gene H3t. Testicular tissue sections of H3tΔ/Δ mice exhibited an increased interstitial area compared with those of wild-type mice, which was primarily attributed to an increase in Leydig cell numbers. Furthermore, this increase in Leydig cells led to increased testosterone synthesis, which occurred alongside cellular senescence-associated β-galactosidase activity. These findings suggest that Leydig cells monitor the progress of spermatogenesis and possess a mechanism to promote functional germ cell formation.

G-quadruplex stabilizer CX-5461 effectively combines with radiotherapy to target ATRX-deficient malignant glioma.

Inactivation of α-thalassaemia/mental retardation X-linked (ATRX) represents a defining molecular feature in large subsets of malignant glioma. ATRX deficiency gives rise to abnormal G-quadruplex (G4) DNA secondary structures, enhancing replication stress and genomic instability. Building on earlier work, we evaluated the extent to which pharmacological G4 stabilization selectively enhances DNA damage and cell death in ATRX-deficient preclinical glioma models. Using the G4 stabilizer CX-5461, we treated patient-derived glioma stem cells (GSCs) in vitro and GSC flank and intracranial murine xenografts in vivo to evaluate efficacy as both a single agent and in combination with ionizing radiation (IR), the latter a central element of current treatment standards. CX-5461 promoted dose-sensitive lethality in ATRX-deficient GSCs relative to ATRX-intact controls. Mechanistic studies revealed that CX-5461 disrupted histone variant H3.3 deposition, enhanced replication stress and DNA damage, activated p53-independent apoptosis, and induced G2/M arrest to a greater extent in ATRX-deficient GSCs than in ATRX-intact counterparts. These data were corroborated in vivo, where CX-5461/IR treatment profoundly delayed tumor growth and prolonged survival in mice bearing ATRX-deficient flank xenografts. Histopathological analyses revealed decreased proliferation, increased apoptosis, and significant G4 induction, replication stress, and DNA damage in CX-5461-treated tumors, both alone and in combination with IR. Finally, despite suboptimal blood-brain-barrier penetration, systemic CX-5461 treatment induced tangible pharmacodynamic effects in ATRX-deficient intracranial GSC models. In totality, our work substantively demonstrates efficacy and defines mechanisms of action for G4 stabilization as a novel therapeutic strategy targeting ATRX-deficient malignant glioma, laying the groundwork for clinical translation.

Cancer-associated DAXX mutations reveal a critical role for ATRX localization in ALT suppression.

To maintain genome stability, proliferating cells must enact a program of telomere maintenance. While most tumors maintain telomeres through the action of telomerase, a subset of tumors utilize a DNA-templated process termed Alternative Lengthening of Telomeres or ALT. ALT is associated with mutations in the ATRX/DAXX/H3.3 histone chaperone complex, which is responsible for deposition of non-replicative histone variant H3.3 at heterochromatic regions of the genome including telomeres. We wished to better understand the role DAXX plays in ALT suppression, and to determine which disease-associated DAXX mutations are unable to suppress ALT. To answer this question, we have leveraged the G292 cell line, in which ATRX is wild type but DAXX has undergone a fusion event with the non-canonical kinesin KIFC3. Restoration of wild-type DAXX in G292 localizes ATRX and abrogates ALT. Using this model system, we tested the ability of a panel of disease-associated DAXX missense variants to suppress ALT. Missense mutations in the ATRX binding domain, the histone binding domain, and the C-terminal SUMO interaction motif reduce the ability of DAXX to suppress ALT. Unexpectedly, we find that mutations in the DAXX histone binding domain lead to failure of ATRX localization. We conclude that a key function of DAXX in ALT suppression is the localization of ATRX to nuclear foci.

Transcription of a centromere-enriched retroelement and local retention of its RNA are significant features of the CENP-A chromatin landscape

BackgroundCentromeres depend on chromatin containing the conserved histone H3 variant CENP-A for function and inheritance, while the role of centromeric DNA repeats remains unclear. Retroelements are prevalent at centromeres across taxa and represent a potential mechanism for promoting transcription to aid in CENP-A incorporation or for generating RNA transcripts to maintain centromere integrity.ResultsIn this study, we probe into the transcription and RNA localization of the centromere-enriched retroelement G2/Jockey-3 (hereafter referred to as Jockey-3) in Drosophila melanogaster, currently the only in vivo model with assembled centromeres. We find that Jockey-3 is a major component of the centromeric transcriptome and produces RNAs that localize to centromeres in metaphase. Leveraging the polymorphism of Jockey-3 and a de novo centromere system, we show that these RNAs remain associated with their cognate DNA sequences in cis, suggesting they are unlikely to perform a sequence-specific function at all centromeres. We show that Jockey-3 transcription is positively correlated with the presence of CENP-A and that recent Jockey-3 transposition events have occurred preferentially at CENP-A-containing chromatin.ConclusionsWe propose that Jockey-3 preferentially inserts at the centromere to ensure its own selfish propagation, while contributing to transcription across these regions. Given the conservation of retroelements as centromere components through evolution, our findings may offer a basis for understanding similar associations in other species.

CNSC-36. REGULATION OF CELL FATE IN PAEDIATRIC HIGH-GRADE GLIOMA BY THE HOMEOBOX TRANSCRIPTION FACTOR DLX2

Abstract Paediatric high-grade gliomas (pHGG) are nearly uniformly fatal cancers that arise predominantly in children and adolescents and encompass Diffuse Midline Glioma (DMG) and Diffuse Hemispheric Glioma (DHG). Most patients harbour mutations in histone variants H3.1 or H3.3, resulting in global epigenetic dysregulation and a stalled oligodendroglial progenitor (OPC) or GABAergic interneuron progenitor (IP) fate for DMG and DHG, respectively. DLX2, a homeobox transcription factor, represses OPC fate and promotes IP cell fate and migration during early neurogenesis. Our lab has shown that Dlx2 binds to and regulates the promoters of Gad1/Gad2, as well as early (Olig2, Nkx2.2) and late (Myt1, Plp1) genes required for OPC differentiation in vivo. Co-expression of Dlx2 with these target sequences reduces reporter gene expression in vitro and Dlx1/2 double knockout mice exhibit increased expression of these OPC markers in vivo. Transient overexpression of a Dlx2-GFP construct in murine DMG cells led to significant IP marker increase (Gad1/2), decrease of OPC markers (Olig2, Nkx2.2) and global restoration of H3K27me3. Additionally, decreased proliferation, colony growth, invasion and migration were observed in vitro. To translate these findings in human pHGG, analysis of a bulk RNA-seq database of 62 patient-derived pHGG cell lines revealed an inverse relationship between DLX2 and OLIG2. DLX2 was knocked out of DLX2high/OLIG2low DHG cell lines using CRISPR-Cas9, and overexpressed in DLX2low/OLIG2high DMG cell lines using a DLX2-mCherry overexpression construct. Evaluation of cell fate markers and epigenetic marks will be presented. Changes in migration, invasion, and proliferation in vitro will also be presented, in addition to changes in tumour growth using a neonatal xenograft murine model in vivo. Manipulation of DLX2 in pHGG provides a model for investigating the link between the factors that control cell fate decisions in the developing brain and the aberrant differentiation state in pHGG.

Identification and annotation of centromeric hypomethylated regions with Centromere Dip Region (CDR)-Finder.

Centromeres are chromosomal regions historically understudied with sequencing technologies due to their repetitive nature and short-read mapping limitations. However, recent improvements in long-read sequencing allowed for the investigation of complex regions of the genome at the sequence and epigenetic levels. Here, we present Centromere Dip Region (CDR)-Finder: a tool to identify regions of hypomethylation within the centromeres of high-quality, contiguous genome assemblies. These regions are typically associated with a unique type of chromatin containing the histone H3 variant CENP-A, which marks the location of the kinetochore. CDR-Finder identifies the CDRs in large and short centromeres and generates a BED file indicating the location of the CDRs within the centromere. It also outputs a plot for visualization, validation, and downstream analysis. CDR-Finder is available at https://github.com/EichlerLab/CDR-Finder.

H3.3K122A results in a neomorphic phenotype in mouse embryonic stem cells

Canonical histone H3 and histone variant H3.3 are posttranslationally modified with the genomic distribution of these marks denoting different features and these modifications may influence transcription. While the majority of posttranslational modifications occur on histone tails, there are defined modifications within the globular domain, such as acetylation of H3K122/H3.3K122. To understand the function of the amino acid H3.3K122 in transcriptional regulation, we attempted to generate H3.3K122A mouse embryonic stem (mES) cells but were unsuccessful. Through multi-omic profiling of mutant cell lines harboring two or three of four H3.3 targeted alleles, we have uncovered that H3.3K122A is neomorphic and results in lethality. This is surprising as prior studies demonstrate H3.3-null mES cells are viable and pluripotent but exhibit a reduced differentiation capacity. Together, these studies have uncovered a novel dependence of a globular domain residue within H3.3 for viability and broadened our understanding of how histone variants contribute to transcription regulation and pluripotency in mES cells.

On the possibility of yet a third kinetochore system in the protist phylum Euglenozoa.

A macromolecular assembly called the kinetochore is essential for the segregation of genetic material during eukaryotic cell division. Therefore, characterization of kinetochores across species is essential for understanding the mechanisms involved in this key process across the eukaryotic tree of life. In particular, little is known about kinetochores in divergent protists such as Euglenozoa, a group of unicellular flagellates that includes kinetoplastids, euglenids, and diplonemids, the latter being a highly diverse and abundant component of marine plankton. While kinetoplastids have an unconventional kinetochore system and euglenids have a canonical one similar to traditional model eukaryotes, preliminary searches detected neither unconventional nor canonical kinetochore components in diplonemids. Here, we employed state-of-the-art deep homology detection protocols but still could not detect orthologs for the bulk of kinetoplastid-specific nor canonical kinetochore proteins in diplonemids except for a putative centromere-specific histone H3 variant. Our results suggest that diplonemids evolved kinetochores that do not resemble previously known ones.

The white gene as a transgenesis marker for the cricket Gryllus bimaculatus.

The cricket Gryllus bimaculatus is an emerging model insect of the order Orthoptera that is used in a wide variety of biological research themes. This hemimetabolous species appears highly complementary to Drosophila and other well-established holometabolous models. To improve transgenesis applications in G. bimaculatus, we have designed a transformation marker gene inspired from the widespread Drosophila mini-white+. Using CRISPR/Cas9, we first generated a loss-of-function mutant allele of the Gb-white gene (Gb-w), which exhibits a white eye coloration at all developmental stages. We then demonstrate that transgenic insertions of a piggyBac vector containing a 3xP3-Gb-w+ cassette rescue eye pigmentation. As an application, we used this vector to generate G. bimaculatus lines expressing a centromeric histone H3 variant (CenH3.1) fused to EGFP and validated EGFP-CenH3.1 detection at cricket centromeres. Finally, we demonstrate that Minos-based germline transformation and site-specific plasmid insertion with the ΦC31 integrase system function in G. bimaculatus.

Structure and evolution of metapolycentromeres.

Metapolycentromeres consist of multiple sequential domains of centromeric chromatin associated with a centromere-specific variant of histone H3 (CENP-A), functioning collectively as a single centromere. To date, they have been revealed in nine flowering plant, five insect and six vertebrate species. In this paper, we focus on their structure and possible mechanisms of emergence and evolution. The metapolycentromeres may vary in the number of centromeric domains and in their genetic content and epigenetic modifications. However, these variations do not seem to affect their function. The emergence of metapolycentromeres has been attributed to multiple Robertsonian translocations and segmental duplications. Conditions of genomic instability, such as interspecific hybridization and malignant neoplasms, are suggested as triggers for the de novo emergence of metapolycentromeres. Addressing the "centromere paradox" - the rapid evolution of centromeric DNA and proteins despite their conserved cellular function - we explore the centromere drive hypothesis as a plausible explanation for the dynamic evolution of centromeres in general, and in particular the emergence of metapolycentromeres and holocentromeres. Apparently, metapolycentromeres are more common across different species than it was believed until recently. Indeed, a systematic review of the available cytogenetic publications allowed us to identify 27 candidate species with metapolycentromeres. Тhe list of the already established and newly revealed candidate species thus spans 27 species of flowering plants and eight species of gymnosperm plants, five species of insects, and seven species of vertebrates. This indicates an erratic phylogenetic distribution of the species with metapolycentromeres and may suggest an independent emergence of the metapolycentromeres in the course of evolution. However, the current catalog of species with identified and likely metapolycentromeres remains too short to draw reliable conclusions about their evolution, particularly in the absence of knowledge about related species without metapolycentromeres for comparative analysis. More studies are necessary to shed light on the mechanisms of metapolycentromere formation and evolution.

The HSV-1 encoded CCCTC-binding factor, CTRL2, impacts the nature of viral chromatin during HSV-1 lytic infection.

HSV-1 genomes are rapidly heterochromatinized following entry by host cells to limit viral gene expression. Efficient HSV-1 genome replication requires mechanisms that de-repress chromatin associated with the viral genome. CCCTC-binding factors, or CTCF insulators play both silencing and activating roles in cellular transcriptional regulation. Importantly, the HSV-1 genome encodes several CTCF insulators that flank IE genes, implying that individual HSV-1 encoded CTCF insulators regulate IE transcription during all stages of the HSV-1 life cycle. We previously reported that the HSV-1 encoded CTCF insulator located downstream of the LAT (CTRL2) controlled IE gene silencing during latency. To further characterize the role of this insulator during the lytic infection we leveraged a ΔCTRL2 recombinant virus to show that there was a genome replication defect that stemmed from decreased IE gene expression in fibroblasts and epithelial cells at early times following initiation of infection. Further experiments indicated that the defect in gene expression resulted from chromatin inaccessibility in the absence of the insulator. To elucidate how chromatin accessibility was altered in the absence of the CTRL2 insulator, we showed that enrichment of Alpha-thalassemia/mental retardation, X-linked chromatin remodeler (ATRX), and the histone variant H3.3, both of which are known for their roles in maintaining repressive histone markers on the HSV-1 viral genome were increased on IE regions of HSV-1. Finally, both H3K27me3 and H3K9me3 repressive histone marks remained enriched by 4 hours post infection in the absence of the CTRL2 insulator, confirming that the CTRL2 insulator is required for de-repression of IE genes of viral genomes. To our knowledge these are the first data that show that a specific CTCF insulator in the HSV-1 genome (CTRL2) regulates chromatin accessibility during the lytic infection.

Argonaute protein CSR-1 restricts localization of holocentromere protein HCP-3, the C. elegans CENP-A homolog.

Chromosome segregation errors caused by centromere malfunction can lead to chromosome instability and aneuploidy. In Caenorhabditis elegans, the Argonaute protein CSR-1 is essential for proper chromosome segregation, although the specific mechanisms are not fully understood. Here, we investigated how CSR-1 regulates centromere and kinetochore function in C. elegans embryos. We found that depletion of CSR-1 results in defects in mitotic progression and chromosome positioning relative to the spindle pole. Knockdown of CSR-1 does not affect mRNA and protein levels of the centromeric histone H3 variant and CENP-A homolog HCP-3 but does increase the localization of HCP-3 and some kinetochore proteins to the mitotic chromosomes. Such elevation of HCP-3 chromatin localization depends on EGO-1, which is an upstream factor in the CSR-1 RNA interference (RNAi) pathway, and PIWI domain activity of CSR-1. Our results suggest that CSR-1 restricts the level of HCP-3 at the holocentromeres, prevents erroneous kinetochore assembly and thereby promotes accurate chromosome segregation. Our work sheds light on the role of CSR-1 in regulating deposition of HCP-3 on chromatin and centromere function in embryos.

Age-related histone H3.3 accumulation associates with a repressive chromatin in mouse tibialis anterior muscle

The present study aimed to investigate age-related changes in histone variant H3.3 and its role in the aging process of mouse tibialis anterior muscle. H3.3 level significantly increased with age and correlated with H3K27me3 level. Acute exercise successfully upregulated the target gene expression in 8-wk-old mice, whereas no upregulation was noted in 53-wk-old mice. H3K27me3 level was increased at these loci in response to acute exercise in 8-wk-old mice. However, in 53-wk-old mice, H3.3 and H3K27me3 levels were increased at rest and were not affected by acute exercise. Furthermore, forced H3.3 expression in the skeletal muscle of 8-wk-old mice led to a gradual improvement in motor function. The results suggest that age-related H3.3 accumulation induces the formation of repressive chromatin in the mouse tibialis anterior muscle. However, H3.3 accumulation also appears to play a positive role in enhancing skeletal muscle function.

Centromere inactivation during aging can be rescued in human cells.

Aging involves a range of genetic, epigenetic, and physiological alterations. A key characteristic of aged cells is the loss of global heterochromatin, accompanied by a reduction in canonical histone levels. In this study, we track the fate of centromeres during aging in human cells. Our findings reveal that the centromeric histone H3 variant CENP-A is downregulated in aged cells, in a p53-dependent manner. We observe repression of centromeric noncoding transcription through an epigenetic mechanism via recruitment of a lysine-specific demethylase 1 (LSD1/KDM1A) to centromeres. This suppression results in defective de novo CENP-A loading at aging centromeres. By dual inhibition of p53 and LSD1/KDM1A in aged cells, we mitigate the reduction in centromeric proteins and centromeric transcripts, leading to mitotic rejuvenation of these cells. These results offer insights into a novel mechanism for centromeric inactivation during aging and provide potential strategies to reactivate centromeres.