Aging Cell最新文献

Age-related macular degeneration (AMD) is a progressive disorder and the leading cause of central vision loss. Age is the most important risk factor, followed by genetics and smoking. However, ageing is a complex process, and biological age can deviate from chronological age between individuals and within different organ systems. Initially, we used machine learning to predict the biological age of the immune, cardiovascular, pulmonary, renal, musculoskeletal, metabolic and hepatic systems by analysing various physiological and physical markers in the UK Biobank cohort. Then, we investigated the association of each organ's biological age with incident AMD derived from electronic health record data as well as with different AMD genetic risk scores. We observed that most organ systems in participants who developed AMD after recruitment showed accelerated ageing compared with controls, with the immune system being the most affected, especially in younger males. Surprisingly, we found that AMD patients showed slower ageing of their hepatic system compared to controls, particularly in female patients. The overall AMD genetic risk score was associated with faster organ ageing across all tissues except cardiovascular and pulmonary, while genetic risk scores stratified by pathways differently influenced each organ system. In conclusion, we found differential organ ageing associated with AMD. Significantly, genetic risk variants of AMD are associated with differential ageing of various organ systems.

Increased expression of the cyclin-dependent kinase inhibitor p16Ink4a (p16) is detected in neurons of human Alzheimer's disease (AD) brains and during normal aging. Importantly, selective eliminating p16-expressing cells in AD mouse models attenuates tau pathologies and improves cognition. But whether and how p16 contributes to AD pathogenesis remains unclear. To address this question, we tested whether induction of p16 expression in neurons exacerbates AD pathologies. We created a doxycycline-inducible system to trigger p16 up-regulation in human-induced pluripotent stem cells (iPSCs) and neurons differentiated from iPSCs. We demonstrated that up-regulated p16 expression in iPSCs reduces cell proliferation, down-regulates cell cycle genes, and up-regulates genes involved in focal adhesion, interferon α response and PI3K-Akt signaling. Our approach enables temporal control of p16 induction upon differentiation from iPSCs to neurons. In differentiated cortical neurons, we found that up-regulation of p16 increases tau phosphorylation at Ser202/Thr205 and Thr231 in a cell-autonomous manner, while amyloid beta secretion is not affected. These data suggest a critical role of p16 in regulating tau phosphorylation in neurons, and thereby contributing to pathological progression of AD. As pathological tau tangles have been shown to induce p16 expression, our studies suggest a positive feedback loop between p16 and tau to exacerbate tau pathologies.

From embryogenesis to aging, billions of cells perish daily in mammals. The multistep process by which phagocytes engulf these deceased cells without eliciting an inflammatory response is called efferocytosis. Despite significant insights into the fundamental mechanisms of efferocytosis, its implications in disorders such as aging and cancer remain elusive. Upon summarizing and analyzing existing studies on efferocytosis, it becomes evident that efferocytosis is our friend in resolving inflammation, yet it transforms into our foe by facilitating tumor development and metastasis. This review illuminates recent discoveries regarding the emerging mechanisms of efferocytosis in clearing apoptotic cells, explores its connections with aging, examines its influence on tumor development and metastasis, and identifies the regulatory factors of efferocytosis within the tumor microenvironment. A comprehensive understanding of these efferocytosis facets offers insights into crucial physiological and pathophysiological processes, paving the way for innovative therapeutic approaches to combat aging and cancer.

Microglia, as resident immune cells in the central nervous system (CNS), play a crucial role in maintaining homeostasis and phagocytosing metabolic waste in the brain. Senescent microglia exhibit decreased phagocytic capacity and increased neuroinflammation through senescence-associated secretory phenotype (SASP). This process contributes to the development of various neurodegenerative diseases, including Alzheimer's disease (AD). In this study, we found that SASP was elevated in senescent microglia, and proteomics showed that Tgm2 was upregulated. Mechanistically, we revealed that Tgm2-catalyzed covalent cross-linking of IκBα at K22 and Q248 residues in the cytoplasm of microglia, resulting in the reduction of IκBα and nuclear translocation of NF-κB to promote SASP production. Treatment of senescent microglia with Tgm2 inhibitors (Tg2-IN1 and Cys-D) resulted in reduced NF-κB nuclear translocation and decreased SASP. Additionally, oral administration of Cys-D significantly improved the aging phenotype in aged mice. To summarize, Tgm2 is a potential target for antiaging, and inhibitors of Tgm2 can serve as novel prophylactics or senomorphics.

Aging is a major risk factor for poor outcomes following respiratory infections. In animal models, the most severe outcomes of respiratory infections in older hosts have been associated with an increased burden of senescent cells that accumulate over time with age and create a hyperinflammatory response. Although studies using coronavirus animal models have demonstrated that removal of senescent cells with senolytics, a class of drugs that selectively kills senescent cells, resulted in reduced lung damage and increased survival, little is known about the role that senescent cells play in the outcome of influenza A viral (IAV) infections in aged mice. Here, we tested if the aged mice survival or weight loss IAV infections could be improved using three different senolytic regimens. We found that neither dasatinib plus quercetin, fisetin, nor ABT-263 improved outcomes. Furthermore, both dasatanib plus quercetin and fisetin treatments further suppressed immune infiltration than aging alone. Additionally, our data show that the short-term senolytic agents do not reduce senescent markers in our aged mouse model. These findings suggest that acute senolytic treatments do not universally reverse aging related immune phenotype against all respiratory viral infections.

Neovascular age-related macular degeneration (nAMD), characterized by choroidal neovascularization (CNV), is one of the leading causes of severe visual impairment and irreversible vision loss around the world. Subretinal fibrosis (SRF) contributes to the incomplete response to anti-vascular endothelial growth factor (VEGF) treatment and is one of the main reasons for long-term poor visual outcomes in nAMD. Reducing SRF is urgently needed in the anti-VEGF era. The role of non-coding RNAs has been implicated in CNV; however, their roles in SRF have not been elucidated yet. Herein, we comprehensively investigated circular RNA (circRNA) profiles in the laser-induced mouse SRF model and the transforming growth factor-β (TGF-β) induced human umbilical vein endothelial cell (HUVEC) fibrosis model. A novel circRNA, circSIRT2, was identified, and its function in SRF and endothelial-to-mesenchymal transition (EndMT) regulation was investigated. circSIRT2 was consistently upregulated in fibrotic models in vivo and in vitro. circSIRT2 overexpression downregulated the fibrotic markers and inhibited the proliferation and migration of endothelial cells in vitro. circSIRT2 overexpression in vivo also reduced SRF area in mice. Mechanistically, circSIRT2 functioned by sponging miR-542-3p, which further upregulated the expression of vasohibin-1 (VASH1) and reduced SRF lesion development. Vitreous delivery of miR-542-3p and VASH1 in the mouse SRF model also confirmed the pro-fibrotic function of miR-542-3p and anti-fibrotic function of VASH1, respectively. In conclusion, circSIRT2 inhibited SRF by binding miR-542-3p, which stimulated the VASH1 expression and subsequently suppressed EndMT. The circSIRT2/miR-542-3p/VASH1 axis may serve as a promising therapeutic target for SRF in nAMD.

Endothelial dysfunction, characterized by a decline in endothelial physiological functions, is a significant aspect of cardiovascular aging, contributing notably to arterial stiffness, atherosclerosis, and hypertension. Transient receptor potential channel V4 (TRPV4), a key member of Ca²⁺-permeable channels, plays a crucial role in maintaining vascular functions. However, the role and mechanisms of TRPV4 in aging-related endothelial dysfunction remain incompletely understood. Here, we demonstrated a marked reduction in endothelial TRPV4 function without alterations in its expression, leading to abnormal endothelial Ca²⁺ signaling and impaired vasodilation in aging mesenteric arteries. Employing transcriptome sequencing, co-IP, and PLA assays, we characterized G protein-coupled receptor 35 (GPR35) interacting with TRPV4, and abnormally enhanced interactions were found in aging endothelial cells. Subsequently, we revealed that intensive GPR35-TRPV4 interaction significantly contributes to endothelial dysfunction during aging, utilizing TRPV4 endothelial-specific knockout (TRPV4_EC ^-/-), AAV-FLT1-shRNA (GPR35) mice, and GPR35 overexpressed/knocked-down HUVECs. Furthermore, molecular docking analysis and subsequent co-IP and pressure myograph experiments indicated that both Thonningianin A and Carfilzomib efficiently restored the GPR35-TRPV4 interaction, preventing endothelial dysfunction and vasodilation impairment. Our study identifies the crucial role of GPR35-TRPV4 interaction in aging-associated abnormal endothelial function and vascular tone modulation. Restoring GPR35-TRPV4 interaction via Thonningianin A or Carfilzomib represents a promising precision approach for aging-related endothelial dysfunction.

T-cell receptor (TCR) diversity is crucial for adaptive immunity, yet baseline characterizations in pediatric populations remain sparse. We sequenced the TCRβ chain of 325 healthy Chinese children aged 0-18, categorized into six age groups. We also analyzed cellular composition and TCRβ associations using flow cytometry in 81 of these samples. Our results indicate a decrease in TCRβ diversity with age, characterized by an increase in high-frequency clonotypes and notable changes in CDR3 length and V(D)J gene usage. These changes are influenced by early life vaccinations and antigen exposures. Additionally, we found a significant association between reduced TCRβ diversity and a decrease in CD4⁺ T naïve cells. We also developed a predictive model that identifies specific TCRβ features as potential biomarkers for biological age, validated by their significant correlation with changes in the immune repertoire. These findings enhance our understanding of age-related variations in the TCRβ repertoire among children, providing resourceful information for research on pediatric TCR in health and disease.

With advancing age, significant changes occur in the female reproductive system, the most notable of which is the decline in oocyte quality, a key factor affecting female fertility. However, the mechanisms underlying oocyte aging remain poorly understood. In this study, we obtained oocytes from aged and young female mice and performed single-cell transcriptome sequencing, comparing our findings with existing proteomic analyses. Our analysis revealed that one of the primary characteristics of aging oocytes is the disruption of calcium ion homeostasis. Specifically, we identified two key genes involved in the oocyte aging process, Calb1 and Rpl23. Experimental validation demonstrated that knockdown of CALB1 in oocytes led to reduced calcium ion levels in the endoplasmic reticulum and mitochondria, resulting in mitochondrial dysfunction and meiotic defects. Further experiments suggested that RPL23 may function as a downstream gene of CALB1, and its knockdown caused mitochondrial dysfunction, excessive accumulation of reactive oxygen species (ROS), and spindle assembly defects. Notably, overexpression of these two genes in aging oocytes partially rescued the maternal age-related defective phenotypes, underscoring their crucial roles in oocyte aging. This study provides a comprehensive understanding of the specific mechanisms underlying mouse oocyte aging at single-cell resolution, supported by experimental validation, and offers new directions and potential targets for future research into age-related reproductive health issues.

Aging-related metabolic disorders seriously affect the lifespan of middle-aged and older people, potentially due to disruptions in the adaptive immune and gut microbial profiles. Dietary intervention offers a promising strategy for maintaining metabolic health. This study aimed to investigate the ameliorative effect of 2'-fucosyllactose (2'-FL) on aging-induced metabolic dysfunction and the underlying mechanisms. The results revealed that 2'-FL significantly relieved aging-related metabolic disorders, including weight gain, lipid deposition, dyslipidemia, glucose intolerance, systemic inflammation, and abnormal hepatic metabolism. Flow cytometry analysis revealed a significant reduction in T cytotoxic (Tc), T helper (Th), and regulatory T (Treg) cells and a significant increase in Th17 cells in aged mice, while 2'-FL relieved the aging-induced proportional changes in Th and Th17 subtypes. The aging intestinal microecology was characterized by higher Th17/Treg ratios, impaired gut barrier function, lower gut bacterial diversity, decreased abundance of beneficial genera including Ligilactobacillus, Colidextribacter, Mucispirillum, and Lachnoclostridium, and increased abundance of harmful bacteria including Turicibacter and Desulfovibrio, which was ameliorated by 2'-FL treatment. These findings highlight that 2'-FL is an ideal dietary prebiotic for improving aging-related metabolic disorders by modulating both the adaptive immune system and the gut microbial profile.