Biology subjects

Horikawa, I.

Publications and source records attributed to Horikawa, I..

5 recordsLinked to original sources

bioRxiv2026

The senescence-inhibitory p53 isoform Δ133p53α represses the proinflammatory chemokine CXCL10 in progeria model mice and naturally aged mice

Aims{Delta}133p53 is a naturally occurring isoform of the human p53 protein that inhibits p53-mediated cellular senescence. We previously reported that transgenic expression of this senescence-inhibitory p53 isoform counteracts aging-associated pathological changes in progeria model mice (heterozygous LmnaG609G/+). The anti-aging effect of {Delta}133p53 was attributed in part to reduced levels of the proinflammatory cytokine IL-6. This study aims to comprehensively profile {Delta}133p53-induced changes in cytokines and chemokines. MethodsA Luminex-based multiplex quantitative assay was performed using mouse serum samples from transgenic {Delta}133p53-expressing LmnaG609G/+ mice and non-expressing controls. Quantitative RT-PCR and RNA in situ hybridization assays were used to assess Cxcl10 expression in mouse tissues. In addition, gene expression datasets from human tissues were analyzed. ResultsWe confirmed {Delta}133p53-mediated repression of serum IL-6 levels. We also found that {Delta}133p53 reduced serum levels of CXCL1, IL-1, and CXCL10. We further characterized CXCL10, which has not previously been associated with progeria in mice or humans. Consistent with reduced serum CXCL10 levels, both young (15-week-old) and old (10-month-old) {Delta}133p53-expressing LmnaG609G/+ mice showed reduced Cxcl10 expression in the liver, spleen, and brain, major organs that produce CXCL10, compared with age-matched non-expressing controls. In naturally aged wild-type mice (2 years old), transgenic {Delta}133p53 expression also significantly repressed Cxcl10 expression in the spleen and brain. An inverse association between CXCL10 and {Delta}133p53 levels was observed in human spleen tissues, suggesting physiological relevance to human aging. ConclusionCXCL10, a proinflammatory chemokine elevated in both accelerated and natural aging, is a potential target of the anti-inflammatory activity of {Delta}133p53.

physiology↗

bioRxiv2026

Senescence-inhibitory Δ133p53α counteracts accelerated ageing and mortality

Research on progeria not only contributes to treatments for the disease but also enhances our understanding of physiological ageing1. Mouse models of progeria recapitulate pathological ageing phenotypes seen in patients, including cardiovascular defects, increased cellular senescence, systemic inflammation, DNA damage accumulation, and shortened lifespan2. In cultured cells from Hutchinson-Gilford progeria syndrome (HGPS) patients, the human p53 isoform {Delta}133p53 was previously shown to inhibit p53-mediated cellular senescence, proinflammatory IL-6 production, and DNA damage accumulation, and to extend cellular replicative lifespan3. Here we show that, in a heterozygous HGPS mouse model4, transgenic expression of {Delta}133p53 reproduces these in vitro-observed effects across multiple organs in vivo and extends median lifespan by 11% (387 versus 349 days, P = 0.0379). In the aorta and skin, {Delta}133p53 abrogates progeria-characteristic pathological changes and preserves tissue integrity. Our data further suggest that {Delta}133p53 may promote a broad spectrum of ageing-counteracting mechanisms, including bone homeostasis, metabolic fitness, antioxidant defense, youthful epigenome, and tissue stemness. Together with the anti-inflammatory and tissue-preserving effects of {Delta}133p53 in naturally aged mice and its age-associated downregulation in human tissues, this study suggests that {Delta}133p53-based therapeutic strategies may be applicable not only to HGPS but also as broader interventions for preventing or delaying ageing.

physiology↗

bioRxiv2025

Pharmacologic activation of Δ133p53α reduces cellular senescence in progeria patients-derived cells

BackgroundPatients with Hutchinson-Gilford progeria syndrome (HGPS) show accelerated aging phenotypes and have shortened lifespan, with implications in physiological aging processes as well. While therapeutic approaches targeting the disease-causing abnormal protein, progerin, have been developed, further efforts to explore mechanistically distinct and complementary strategies are still critical to better treatment regimens. We previously showed that lentiviral vector-driven expression of {Delta}133p53, a natural inhibitory isoform of p53, rescued HGPS patients-derived fibroblasts from early entry into cellular senescence, which is a downstream event of progerin-induced DNA damage. We also performed a quantitative high-throughput screen (qHTS) of approved drug and investigational agent libraries, leading to the identification of celastrol and AZD1981 as compounds that upregulate {Delta}133p53 protein levels. MethodsTo investigate whether celastrol and ADZ1981 upregulate endogenous {Delta}133p53 in HGPS-derived fibroblasts and reduce their senescence-associated phenotypes, we performed western blot assays ({Delta}133p53, progerin, and p21WAF1, which mediates p53-induced senescence and is inhibited by {Delta}133p53), senescence-associated {beta}-galactosidase (SA-{beta}-gal) staining, enzyme-linked immunosorbent assay (IL-6, which is a proinflammatory cytokine secreted from senescent cells), and qRT-PCR assays (p21WAF1 and IL-6). ResultsTreatment with celastrol (0.1 {micro}M for 24 h) or AZD1981 (10 {micro}M for 24 h) reproducibly increased {Delta}133p53 expression and decreased p21WAF1 expression in two strains of fibroblasts derived from HGPS patients. These compounds reduced the percentage of SA-{beta}-gal-positive senescent cells and the secretion of IL-6 into culture medium in both of these fibroblast strains, irrespective of their different basal levels of senescence and IL-6 secretion. These compounds had no effect on the level of progerin. ConclusionCelastrol and ADZ1981 upregulate endogenous {Delta}133p53 and, reproducing the effects of its vector-driven expression, inhibit cellular senescence and IL-6 secretion in HGPS-derived fibroblasts. Their progerin-independent action suggests that they may synergize with currently available progerin-targeting therapies. This study also warrants further investigation of these compounds for potential applications in other diseases and conditions in which {Delta}133p53-regulated senescence plays a role.

cell biology↗

bioRxiv2025

SRSF3 knockdown-induced cellular senescence as a possible therapeutic strategy for non-small cell lung cancer

Tyrosine kinase (TK) inhibitors improve clinical outcomes in non-small cell lung cancer (NSCLC) with targetable mutations. However, such NSCLC cases only consist of about 50% in the western populations. This study, for the first time in NSCLC cells including those without a targetable TK mutation, explores a tumor-suppressive activity of siRNA knockdown of a splicing factor SRSF3, which was reportedly effective in other cancer cell types. The knockdown of SRSF3 increased cellular senescence, indicated by senescence-associated {beta}-galactosidase activity and reduced cell proliferation, in all NSCLC cell lines examined, including A549 (no TK mutation; TP53 wild-type), NCI-H1975 (EGFR L858R/T790M; TP53 R273H mutant), NCI-H322 (no TK mutation; TP53 R248L mutant) and NCI-H596 (no TK mutation; TP53 G245C mutant). An increase in apoptotic cleavage of caspase-3 and poly(ADP-ribose) polymerase was also observed in A549 cells. p53{beta}, a tumor-suppressive p53 isoform generated via alternative mRNA splicing, was upregulated by SRSF3 knockdown, as previously reported in normal fibroblasts. However, neither cellular senescence nor apoptosis was increased by overexpression of p53{beta}, suggesting no or minimum contribution of this p53 isoform to the tumor-suppressive activity of SRSF3 knockdown in NSCLC cells. Our gene expression assay indicated that the SRSF3 knockdown-induced senescence in NSCLC cells may be mediated by downregulation of TOP2A, UBE2C or ASPM, which are known to be oncogenic and are associated with poor patient prognosis. We also generated SRSF3 siRNA-encapsulating lipid nanoparticles as a future therapeutic tool. This study suggests a therapeutic strategy for NSCLC irrespective of the mutation status of TP53 and TK-encoding genes. SummaryKnockdown of a splicing factor SRSF3 increases cellular senescence in NSCLC cells including those with no targetable mutation of tyrosine kinases and thus may represent a novel therapeutic strategy for a hard-to-treat group of NSCLC.

cancer biology↗

bioRxiv2021

Δ133p53α Protects Human Astrocytes from Amyloid-Beta Induced Senescence and Neurotoxicity

Cellular senescence is an important contributor to aging and age-related diseases such as Alzheimers disease (AD). Senescent cells are characterized by a durable cell proliferation arrest and the acquisition of a proinflammatory senescence-associated secretory phenotype (SASP), which participates in the progression of neurodegenerative disorders. Clearance of senescent glial cells in an AD mouse model prevented cognitive decline suggesting pharmacological agents targeting cellular senescence might provide novel therapeutic approaches for AD. {Delta}133p53, a natural protein isoform of p53, was previously shown to be a negative regulator of cellular senescence in primary human astrocyte, with clinical implications from its diminished expression in brain tissues from AD patients. Here we show that treatment of proliferating human astrocytes with amyloid-beta oligomers (A{beta}), an endogenous pathogenic agent of AD, results in reduced expression of {Delta}133p53, as well as induces the cells to become senescent and express proinflammatory SASP cytokines such as IL-6, IL-1{beta} and TNF. Our data suggest that A{beta}-induced astrocyte cellular senescence is associated with accelerated DNA damage, and upregulation of full-length p53 and its senescence-inducing target gene p21WAF1. We also show that exogenously enhanced expression of {Delta}133p53 rescues human astrocytes from A{beta}-induced cellular senescence and SASP through both protection from DNA damage and dominantnegative inhibition of full-length p53, leading to inhibition of A{beta}-induced, astrocyte-mediated neurotoxicity. The results presented here demonstrate that {Delta}133p53 manipulation could modulate cellular senescence in the context of AD, possibly opening new therapeutic avenues. HIGHLIGHTSO_LIA{beta} diminishes the expression of the p53 isoform {Delta}133p53, and induces cellular senescence, SASP, and DNA damage in human astrocytes. C_LIO_LI{Delta}133p53 protects human astrocytes from A{beta}-induced DNA damage and cellular senescence. C_LIO_LI{Delta}133p53 prevents astrocyte-mediated neurotoxicity to neuro-progenitor cells. C_LI

neuroscience↗