Vaccine Therapy for Heart Failure Targeting the Inflammatory Cytokine Igfbp7.

BACKGROUND: The heart comprises many types of cells such as cardiomyocytes, endothelial cells (ECs), fibroblasts, smooth muscle cells, pericytes, and blood cells. Every cell type responds to various stressors (eg, hemodynamic overload and ischemia) and changes its properties and interrelationships among cells. To date, heart failure research has focused mainly on cardiomyocytes; however, other types of cells and their cell-to-cell interactions might also be important in the pathogenesis of heart failure. METHODS: Pressure overload was imposed on mice by transverse aortic constriction and the vascular structure of the heart was examined using a tissue transparency technique. Functional and molecular analyses including single-cell RNA sequencing were performed on the hearts of wild-type mice and EC-specific gene knockout mice. Metabolites in heart tissue were measured by capillary electrophoresis-time of flight-mass spectrometry system. The vaccine was prepared by conjugating the synthesized epitope peptides with keyhole limpet hemocyanin and administered to mice with aluminum hydroxide as an adjuvant. Tissue samples from heart failure patients were used for single-nucleus RNA sequencing to examine gene expression in ECs and perform pathway analysis in cardiomyocytes. RESULTS: Pressure overload induced the development of intricately entwined blood vessels in murine hearts, leading to the accumulation of replication stress and DNA damage in cardiac ECs. Inhibition of cell proliferation by a cyclin-dependent kinase inhibitor reduced DNA damage in ECs and ameliorated transverse aortic constriction-induced cardiac dysfunction. Single-cell RNA sequencing analysis revealed upregulation of Igfbp7 (insulin-like growth factor-binding protein 7) expression in the senescent ECs and downregulation of insulin signaling and oxidative phosphorylation in cardiomyocytes of murine and human failing hearts. Overexpression of Igfbp7 in the murine heart using AAV9 (adeno-associated virus serotype 9) exacerbated cardiac dysfunction, while EC-specific deletion of Igfbp7 and the vaccine targeting Igfbp7 ameliorated cardiac dysfunction with increased oxidative phosphorylation in cardiomyocytes under pressure overload. CONCLUSIONS: Igfbp7 produced by senescent ECs causes cardiac dysfunction and vaccine therapy targeting Igfbp7 may be useful to prevent the development of heart failure.

Senescence and senolysis in cancer: The latest findings.

Aging is a life phenomenon that occurs in most living organisms and is a major risk factor for many diseases, including cancer. Cellular senescence is a cellular trait induced by various genomic and epigenetic stresses. Senescent cells are characterized by irreversible cell growth arrest and excessive secretion of inflammatory cytokines (senescence-associated secretory phenotypes, SASP). Chronic tissue microinflammation induced by SASP contributes to the pathogenesis of a variety of age-related diseases, including cancer. Senolysis is a promising new strategy to selectively eliminate senescent cells in order to suppress chronic inflammation, suggesting its potential use as an anticancer therapy. This review summarizes recent findings on the molecular basis of senescence in cancer cells and senolysis.

Potential role of Fbxo22 in resistance to endocrine therapy in breast cancer with invasive lobular carcinoma.

BACKGROUND: Invasive lobular carcinoma (ILC) is distinct from invasive ductal carcinoma (IDC) in terms of their hormonal microenvironments that may require different therapeutic strategies. We previously reported that selective estrogen receptor modulator (SERM) function requires F-box protein 22 (Fbxo22). Here, we investigated the role of Fbxo22 as a potential biomarker contributing to the resistance to endocrine therapy in ILC. METHODS: A total of 302 breast cancer (BC) patients including 150 ILC were recruited in the study. Fbxo22 expression and clinical information were analyzed to elucidate whether Fbxo22 negativity could be a prognostic factor or there were any correlations among clinical variables and SERM efficacy. RESULTS: Fbxo22 negativity was significantly higher in ILC compared with IDC (58.0% vs. 27.0%, P < 0.001) and higher in postmenopausal patients than premenopausal patients (64.1% vs. 48.2%, P = 0.041). In the ILC cohort, Fbxo22-negative patients had poorer overall survival (OS) than Fbxo22-positive patients, with 10-year OS rates of 77.4% vs. 93.6% (P = 0.055). All patients treated with SERMs, Fbxo22 negativity resulted in a poorer outcome, with 10-year OS rates of 81.3% vs. 92.3% (P = 0.032). In multivariate analysis regarding recurrence-free survival (RFS) in ILC patients, Fbxo22 status was independently predictive of survival as well as lymph node metastasis. CONCLUSION: Fbxo22 negativity significantly impacts on survival in BC patients with IDC and ILC, and the disadvantage was enhanced among ILC postmenopausal women or patients treated with SERMs. The findings suggest that different therapeutic strategies might be needed according to the different histopathological types when considering adjuvant endocrine therapy.

Immune surveillance of senescence: potential application to age-related diseases.

Several lines of evidence suggest that the age-dependent accumulation of senescent cells leads to chronic tissue microinflammation, which in turn contributes to age-related pathologies. In general, senescent cells can be eliminated by the host's innate and adaptive immune surveillance system, including macrophages, NK cells, and T cells. Impaired immune surveillance leads to the accumulation of senescent cells and accelerates the aging process. Recently, senescent cells, like cancer cells, have been shown to express certain types of immune checkpoint proteins as well as non-classical immune-tolerant MHC variants, leading to immune escape from surveillance systems. Thus, immune checkpoint blockade (ICB) may be a promising strategy to enhance immune surveillance of senescence, leading to the amelioration of some age-related diseases and tissue dysfunction.

Intracellular acidification and glycolysis modulate inflammatory pathway in senescent cells.

Senescent cells accumulate in various organs with ageing, and its accumulation induces chronic inflammation and age-related physiological dysfunctions. Several remodelling of intracellular environments have been identified in senescent cells, including enlargement of cell/nuclear size and intracellular acidification. Although these alterations of intracellular environments were reported to be involved in the unique characteristics of senescent cells, the contribution of intracellular acidification to senescence-associated cellular phenotypes is poorly understood. Here, we identified that the upregulation of TXNIP and its paralog ARRDC4 as a hallmark of intracellular acidification in addition to KGA-type GLS1. These genes were also upregulated in response to senescence-associated intracellular acidification. Neutralization of the intracellular acidic environment ameliorated not only senescence-related upregulation of TXNIP, ARRDC4 and KGA but also inflammation-related genes, possibly through suppression of PDK-dependent anaerobic glycolysis. Furthermore, we found that expression of the intracellular acidification-induced genes, TXNIP and ARRDC4, correlated with inflammatory gene expression in heterogeneous senescent cell population in vitro and even in vivo, implying that the contribution of intracellular pH to senescence-associated cellular features, such as SASP.

Structure of human DPPA3 bound to the UHRF1 PHD finger reveals its functional and structural differences from mouse DPPA3.

DNA methylation maintenance is essential for cell fate inheritance. In differentiated cells, this involves orchestrated actions of DNMT1 and UHRF1. In mice, the high-affinity binding of DPPA3 to the UHRF1 PHD finger regulates UHRF1 chromatin dissociation and cytosolic localization, which is required for oocyte maturation and early embryo development. However, the human DPPA3 ortholog functions during these stages remain unclear. Here, we report the structural basis for human DPPA3 binding to the UHRF1 PHD finger. The conserved human DPPA3 85VRT87 motif binds to the acidic surface of UHRF1 PHD finger, whereas mouse DPPA3 binding additionally utilizes two unique α-helices. The binding affinity of human DPPA3 for the UHRF1 PHD finger was weaker than that of mouse DPPA3. Consequently, human DPPA3, unlike mouse DPPA3, failed to inhibit UHRF1 chromatin binding and DNA remethylation in Xenopus egg extracts effectively. Our data provide novel insights into the distinct function and structure of human DPPA3.

M2 macrophage-derived TGF-ß induces age-associated loss of adipogenesis through progenitor cell senescence.

OBJECTIVES: Adipose tissue is an endocrine and energy storage organ composed of several different cell types, including mature adipocytes, stromal cells, endothelial cells, and a variety of immune cells. Adipose tissue aging contributes to the pathogenesis of metabolic dysfunction and is likely induced by crosstalk between adipose progenitor cells (APCs) and immune cells, but the underlying molecular mechanisms remain largely unknown. In this study, we revealed the biological role of p16high senescent APCs, and investigated the crosstalk between each cell type in the aged white adipose tissue. METHODS: We performed the single-cell RNA sequencing (scRNA-seq) analysis on the p16high adipose cells sorted from aged p16-CreERT2/Rosa26-LSL-tdTomato mice. We also performed the time serial analysis on the age-dependent bulk RNA-seq datasets of human and mouse white adipose tissues to infer the transcriptome alteration of adipogenic potential within aging. RESULTS: We show that M2 macrophage-derived TGF-ß induces APCs senescence which impairs adipogenesis in vivo. p16high senescent APCs increase with age and show loss of adipogenic potential. The ligand-receptor interaction analysis reveals that M2 macrophages are the donors for TGF-ß and the senescent APCs are the recipients. Indeed, treatment of APCs with TGF-ß1 induces senescent phenotypes through mitochondrial ROS-mediated DNA damage in vitro. TGF-ß1 injection into gonadal white adipose tissue (gWAT) suppresses adipogenic potential and induces fibrotic genes as well as p16 in APCs. A gWAT atrophy is observed in cancer cachexia by APCs senescence, whose induction appeared to be independent of TGF-ß induction. CONCLUSIONS: Our results suggest that M2 macrophage-derived TGF-ß induces age-related lipodystrophy by APCs senescence. The TGF-ß treatment induced DNA damage, mitochondrial ROS, and finally cellular senescence in APCs.

Plasma membrane damage limits replicative lifespan in yeast and induces premature senescence in human fibroblasts.

Plasma membrane damage (PMD) occurs in all cell types due to environmental perturbation and cell-autonomous activities. However, cellular outcomes of PMD remain largely unknown except for recovery or death. In this study, using budding yeast and normal human fibroblasts, we found that cellular senescence-stable cell cycle arrest contributing to organismal aging-is the long-term outcome of PMD. Our genetic screening using budding yeast unexpectedly identified a close genetic association between PMD response and replicative lifespan regulations. Furthermore, PMD limits replicative lifespan in budding yeast; upregulation of membrane repair factors ESCRT-III (SNF7) and AAA-ATPase (VPS4) extends it. In normal human fibroblasts, PMD induces premature senescence via the Ca2+-p53 axis but not the major senescence pathway, DNA damage response pathway. Transient upregulation of ESCRT-III (CHMP4B) suppressed PMD-dependent senescence. Together with mRNA sequencing results, our study highlights an underappreciated but ubiquitous senescent cell subtype: PMD-dependent senescent cells.

Molecular Prevalence Study of QX-like Infectious Bronchitis Virus in Japan from 2016 to 2023.

Infectious bronchitis is an acute and highly contagious disease in chickens caused by the infectious bronchitis virus (IBV), which has caused significant economic losses to the poultry industry worldwide. The antigenic variant, the QX-like genotype (GI-19 lineage), has been currently reported in epidemics in East Asia, Southeast Asia, the Middle East, Europe, and Africa. We first reported an epidemic of Japanese QX-like IBVs genetically related to Chinese and South Korean strains in the Kyushu region of Japan in 2020. However, because their nationwide prevalence was unknown, we performed a nationwide survey. The testing of 419 reverse transcription (RT)-PCR-positive samples (376 layers and 43 broilers) of IBV field strains between April 2016 and March 2022 detected two QX-like IBVs in 2019 and 2021 broiler samples from one region. A survey of fecal samples collected from 122-layer farms nationwide between November 2022 and January 2023 detected QX-like IBV genes from seven farms in various regions. Phylogenetic tree analysis on the basis of the S1 gene showed that all QX-like IBVs detected in Japan were genetically related to recent Chinese and South Korean strains. A new RT-PCR assay was developed to distinguish between QX-like IBV and other IBV variants prevalent in Japan, whose results were consistent with those of previously reported identification methods. These results suggest that QX-like IBV is rapidly spreading in Japan and that countermeasures are necessary.

Estudio de la prevalencia molecular del virus de la bronquitis infecciosa similar a la cepa QX en Japón entre los años 2016 al 2023. La bronquitis infecciosa es una enfermedad aguda y altamente contagiosa del pollo causada por el virus de la bronquitis infecciosa (IBV), que ha causado importantes pérdidas económicas a la industria avícola en todo el mundo. Actualmente se ha reportado la variante antigénica, el genotipo similar a la cepa QX (cepa GI-19), en brotes en el este de Asia, el sudeste de Asia, el Medio Oriente, Europa y África. Primeramente, se reportó un brote con virus japoneses similares a QX que eran genéticamente relacionados con cepas chinas y surcoreanas en la región de Kyushu en Japón en el 2020. Sin embargo, debido a que se desconocía su prevalencia a nivel nacional, se realizó una encuesta a nivel nacional. Mediante el análisis de 419 muestras positivas a la presencia de cepas de campo por transcripción reversa (RT) y PCR (376 de ponedoras y 43 de pollos de engorde) entre abril del 2016 y marzo del 2022 se detectaron dos virus de bronquitis infecciosa similares a la cepa QX en el 2019 y en el 2021 en muestras de pollos de engorde de una región. Una encuesta de muestras fecales recolectadas de granjas de 122 ponedoras en todo el país entre noviembre del 2022 y enero del 2023 detectó genes de bronquitis infecciosa similares a la cepa QX de siete granjas en varias regiones. El análisis del árbol filogenético basado en el gene S1 mostró que todos los virus similares a la cepa QX detectados en Japón estaban relacionados genéticamente con cepas recientes de China y Corea del Sur. Se desarrolló un nuevo ensayo de RT-PCR para distinguir entre los virus de bronquitis infecciosa similares a la cepa QX y otras variantes del IBV prevalentes en Japón, cuyos resultados fueron consistentes con los de los métodos de identificación reportados anteriormente. Estos resultados sugieren que virus de bronquitis infecciosa similares a la cepa QX se están extendiendo rápidamente en Japón y que se necesitan medidas de control.

CDCA7 is a hemimethylated DNA adaptor for the nucleosome remodeler HELLS.

Mutations of the SNF2 family ATPase HELLS and its activator CDCA7 cause immunodeficiency-centromeric instability-facial anomalies (ICF) syndrome, characterized by hypomethylation at heterochromatin. The unique zinc-finger domain, zf-4CXXC_R1, of CDCA7 is widely conserved across eukaryotes but is absent from species that lack HELLS and DNA methyltransferases, implying its specialized relation with methylated DNA. Here we demonstrate that zf-4CXXC_R1 acts as a hemimethylated DNA sensor. The zf-4CXXC_R1 domain of CDCA7 selectively binds to DNA with a hemimethylated CpG, but not unmethylated or fully methylated CpG, and ICF disease mutations eliminated this binding. CDCA7 and HELLS interact via their N-terminal alpha helices, through which HELLS is recruited to hemimethylated DNA. While placement of a hemimethylated CpG within the nucleosome core particle can hinder its recognition by CDCA7, cryo-EM structure analysis of the CDCA7-nucleosome complex suggests that zf-4CXXC_R1 recognizes a hemimethylated CpG in the major groove at linker DNA. Our study provides insights into how the CDCA7-HELLS nucleosome remodeling complex uniquely assists maintenance DNA methylation.