A single-cell transcriptomic landscape of primate arterial aging

Impaired ketogenesis in Leydig Cells drives testicular aging

Testicular aging commonly leads to testosterone deficiency and impaired spermatogenesis, yet the underlying mechanisms remain elusive. Here, we show that Leydig cells are particularly vulnerable to aging processes in testis. Single-cell RNA sequencing identifies the expression of Hmgcs2, the gene encoding rate-limiting enzyme of ketogenesis, decreases significantly in Leydig cells from aged mice. Additionally, the concentrations of ketone bodies β-hydroxybutyric acid and acetoacetic acid in young testes are substantially higher than that in serum, but significantly diminish in aged testes. Silencing of Hmgcs2 in young Leydig cells drives cell senescence and accelerated testicular aging. Mechanistically, β-hydroxybutyric acid upregulates the expression of Foxo3a by facilitating histone acetylation, thereby mitigating Leydig cells senescence and promoting testosterone production. Consistently, enhanced ketogenesis by genetic manipulation or oral β-hydroxybutyric acid supplementation alleviates Leydig cells senescence and ameliorates testicular aging in aged mice. These findings highlight defective ketogenesis as a pivotal factor in testicular aging, suggesting potential therapeutic avenues for addressing age-related testicular dysfunction.

Oxidative DNA damage promotes vascular ageing associated with changes in extracellular matrix-regulating proteins

AIMS

Vascular ageing is characterized by vessel stiffening, with increased deposition of extracellular matrix (ECM) proteins including collagens. Oxidative DNA damage occurs in vascular ageing, but how it regulates ECM proteins and vascular stiffening is unknown. We sought to determine the relationship between oxidative DNA damage and ECM regulatory proteins in vascular ageing.

METHODS AND RESULTS

We examined oxidative DNA damage, the major base excision repair (BER) enzyme 8-Oxoguanine DNA Glycosylase (Ogg1) and its regulators, multiple physiological markers of ageing, and ECM proteomics in mice from 22 to 72 w. Vascular ageing was associated with increased oxidative DNA damage, and decreased expression of Ogg1, its active acetylated form, its acetylation regulatory proteins P300 and CBP, and the transcription factor Foxo3a. Vascular stiffness was examined in vivo in control, Ogg1-/-, or mice with vascular smooth muscle cell-specific expression of Ogg1+ (Ogg1) or an inactive mutation (Ogg1KR). Ogg1-/- and Ogg1KR mice showed reduced arterial compliance and distensibility, and increased stiffness and pulse pressure, whereas Ogg1 expression normalized all parameters to 72 w. ECM proteomics identified major changes in collagens with ageing, and downregulation of the ECM regulatory proteins Protein 6-lysyl oxidase (LOX) and WNT1-inducible-signaling pathway protein 2 (WISP2). Ogg1 overexpression upregulated LOX and WISP2 both in vitro and in vivo, and downregulated Transforming growth factor β1 (TGFb1) and Collagen 4α1 in vivo compared with Ogg1KR. Foxo3a activation induced Lox, while Wnt3 induction of Wisp2 also upregulated LOX and Foxo3a, and downregulated TGFβ1 and fibronectin 1. In humans, 8-oxo-G increased with vascular stiffness, while active OGG1 reduced with both age and stiffness.

CONCLUSION

Vascular ageing is associated with oxidative DNA damage, downregulation of major BER proteins, and changes in multiple ECM structural and regulatory proteins. Ogg1 protects against vascular ageing, associated with changes in ECM regulatory proteins including LOX and WISP2.

Prevention of cardiovascular disease for healthy aging and longevity: A new scoring system and related "mechanisms-hallmarks-biomarkers"

Healthy "environment-sleep-emotion-exercise-diet" intervention [E(e)SEEDi] lifestyle can improve the quality of life, prolong aging and promote longevity due to improvement of human immunity and prevention of cardiovascular diseases (CVD). Here, the author reviewed the associations between these core elements with CVD and cardiovascular aging, and developed a new scoring system based on the healthy E(e)SEEDi lifestyle for prediction and evaluation of life expectancy. These core factors are assigned 20 points each (120 points in total), and a higher score predicts healthier aging and longevity. The E(e)SEEDi represents "a tree of life" bearing the fruits of longevity as well as "a rocket of anti-ageing" carrying people around the world on a journey of longevity. In conclusion, the E(e)SEEDi can delay aging and increase the life expectancy due to the role of a series of cellular and molecular "mechanisms-hallmarks-biomarkers". It's believed that the novel scoring system has a huge potential and beautiful prospects.

ARID5A orchestrates cardiac aging and inflammation through MAVS mRNA stabilization

Elucidating the regulatory mechanisms of human cardiac aging remains a great challenge. Here, using human heart tissues from 74 individuals ranging from young (≤35 years) to old (≥65 years), we provide an overview of the histological, cellular and molecular alterations underpinning the aging of human hearts. We decoded aging-related gene expression changes at single-cell resolution and identified increased inflammation as the key event, driven by upregulation of ARID5A, an RNA-binding protein. ARID5A epi-transcriptionally regulated Mitochondrial Antiviral Signaling Protein (MAVS) mRNA stability, leading to NF-κB and TBK1 activation, amplifying aging and inflammation phenotypes. The application of gene therapy using lentiviral vectors encoding shRNA targeting ARID5A into the myocardium not only mitigated the inflammatory and aging phenotypes but also bolstered cardiac function in aged mice. Altogether, our study provides a valuable resource and advances our understanding of cardiac aging mechanisms by deciphering the ARID5A-MAVS axis in post-transcriptional regulation.

Advances and applications in single-cell and spatial genomics

The applications of single-cell and spatial technologies in recent times have revolutionized the present understanding of cellular states and the cellular heterogeneity inherent in complex biological systems. These advancements offer unprecedented resolution in the examination of the functional genomics of individual cells and their spatial context within tissues. In this review, we have comprehensively discussed the historical development and recent progress in the field of single-cell and spatial genomics. We have reviewed the breakthroughs in single-cell multi-omics technologies, spatial genomics methods, and the computational strategies employed toward the analyses of single-cell atlas data. Furthermore, we have highlighted the advances made in constructing cellular atlases and their clinical applications, particularly in the context of disease. Finally, we have discussed the emerging trends, challenges, and opportunities in this rapidly evolving field.

Regional and aging-specific cellular architecture of non-human primate brains

BACKGROUND

Deciphering the functionality and dynamics of brain networks across different regions and age groups in non-human primates (NHPs) is crucial for understanding the evolution of human cognition as well as the processes underlying brain pathogenesis. However, systemic delineation of the cellular composition and molecular connections among multiple brain regions and their alterations induced by aging in NHPs remain largely unresolved.

METHODS

In this study, we performed single-nucleus RNA sequencing on 39 samples collected from 10 brain regions of two young and two aged rhesus macaques using the DNBelab C4 system. Validation of protein expression of signatures specific to particular cell types, brain regions, and aging was conducted through a series of immunofluorescence and immunohistochemistry staining experiments. Loss-of-function experiments mediated by short hairpin RNA (shRNA) targeting two age-related genes (i.e., VSNL1 and HPCAL4) were performed in U251 glioma cells to verify their aging effects. Senescence-associated beta-galactosidase (SA-β-gal) staining and quantitative PCR (qPCR) of senescence marker genes were employed to assess cellular senescence in U251 cells.

RESULTS

We have established a large-scale cell atlas encompassing over 330,000 cells for the rhesus macaque brain. Our analysis identified numerous gene expression signatures that were specific to particular cell types, subtypes, brain regions, and aging. These datasets greatly expand our knowledge of primate brain organization and highlight the potential involvement of specific molecular and cellular components in both the regionalization and functional integrity of the brain. Our analysis also disclosed extensive transcriptional alterations and cell-cell connections across brain regions in the aging macaques. Finally, by examining the heritability enrichment of human complex traits and diseases, we determined that neurological traits were significantly enriched in neuronal cells and multiple regions with aging-relevant gene expression signatures, while immune-related traits exhibited pronounced enrichment in microglia.

CONCLUSIONS

Taken together, our study presents a valuable resource for investigating the cellular and molecular architecture of the primate nervous system, thereby expanding our understanding of the mechanisms underlying brain function, aging, and disease.

Identification of age-related metabolomic signatures in vascular tissues

Vascular aging contributes to the morbidity and mortality in older individuals, closely linked to an imbalance between energy consumption and production. Despite its importance, our understanding of how aging affects vascular metabolism and leads to vascular diseases remains limited. In this study, we explored the metabolomic characteristics of vascular aging by analyzing aortic tissues from young and old mice through untargeted metabolomic analysis using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). We identified 85 differential metabolites, with 37 up-regulated and 48 down-regulated, primarily consisting of lipids and lipid-like molecules, based on the criteria of variable importance in projection (VIP) > 1 and P < 0.05. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed significant involvement of these metabolites in six metabolic pathways (P < 0.05), particularly in glycerophospholipid metabolism. Receiver operating characteristic (ROC) curve analysis highlighted eight altered metabolites in glycerophospholipid metabolism, such as phosphatidylcholine (PC) (17:0/22:6) and lysophosphatidylcholine (LPC) (18:2), which demonstrated strong discriminatory ability for vascular aging with an area under the curve (AUC) exceeding 0.85. This study provides novel insights into metabolomic signature of vascular aging, offering important clues for future treatments of age-related vascular disorders.

A newly discovered bioactive equivalence of combinatorial components of Angong Niuhuang pill improves ischemic stroke via the PI3K/AKT axis

ETHNOPHARMACOLOGICAL RELEVANCE

Angong Niuhuang pill (ANP) is effective in preventing and treating ischemic stroke, however, the pharmacodynamic substances and mechanism of ANP have not been scientifically clarified.

AIM OF THE STUDY

This study aims to identify the bioactive equivalence of combinatorial components (BECCs) of ANP for treating ischemic stroke and discuss the underlying mechanisms.

MATERIALS AND METHODS

Network pharmacology was performed to screen key compounds and predict potential pathways. The effect of BECCs on ischemic stroke was screened and verified in ponatinib-induced zebrafish model and mice middle cerebral artery occlusion (MCAO) model. Finally, the mechanism of BECCs was preliminarily investigated.

RESULTS

Through network pharmacology, the degree values of each component in ANP were determined, and five candidate BECCs were obtained by combining the content of the components in the original prescription. The BECCs V has the same efficacy as the original formula in reducing the movement disorder and neuronal injury of zebrafish cerebral ischemia models and lowering the neurologic deficits and cerebral infarction volume of mouse MCAO models. Mechanistically, BECCs V and ANP blocked neuronal autophagy through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) axis, inhibited microglial inflammatory activation through the PI3K/AKT/hypoxia inducible factor-1α (HIF-1α) axis, protected microvascular endothelial function through the PI3K/AKT/forkhead box O3 (FoxO3a) axis, thereby improving ischemic cerebral injury.

CONCLUSIONS

The newly discovered BECCs V is equivalent to ANP in regulating the motor function recovery rate and neuroprotective rate of zebrafish and the neurological deficit scores and the average infarct volume of MCAO mice. This study suggests that the PI3K/AKT signaling axis plays a key role in neuronal autophagy, microglial inflammatory activation and microvascular endothelial dysfunction induced by cerebral ischemic injury, suggesting that the regulation of PI3K/AKT may be a potential therapeutic strategy for neuroprotection and ischemic stroke injury.

USP25 ameliorates vascular remodeling by deubiquitinating FOXO3 and promoting autophagic degradation of FOXO3

Long-term hypertension causes excessive vascular remodeling and leads to adverse cardiovascular events. Balance of ubiquitination and deubiquitination has been linked to several chronic conditions, including pathological vascular remodeling. In this study, we discovered that the expression of ubiquitin-specific protease 25 (USP25) is significantly up-regulated in angiotensin II (Ang II)-challenged mouse aorta. Knockout of Usp25 augments Ang II-induced vascular injury such as fibrosis and endothelial to mesenchymal transition (EndMT). Mechanistically, we found that USP25 interacts directly with Forkhead box O3 (FOXO3) and removes the K63-linked ubiquitin chain on the K258 site of FOXO3. We also showed that this USP25-mediated deubiquitination of FOXO3 increases its binding to light chain 3 beta isoform and autophagosomic-lysosomal degradation of FOXO3. In addition, we further validated the biological function of USP25 by overexpressing USP25 in the mouse aorta with AAV9 vectors. Our studies identified FOXO3 as a new substrate of USP25 and showed that USP25 may be a potential therapeutic target for excessive vascular remodeling-associated diseases.

SIRT5 safeguards against primate skeletal muscle ageing via desuccinylation of TBK1

Ageing-induced skeletal muscle deterioration contributes to sarcopenia and frailty, adversely impacting the quality of life in the elderly. However, the molecular mechanisms behind primate skeletal muscle ageing remain largely unexplored. Here, we show that SIRT5 expression is reduced in aged primate skeletal muscles from both genders. SIRT5 deficiency in human myotubes hastens cellular senescence and intensifies inflammation. Mechanistically, we demonstrate that TBK1 is a natural substrate for SIRT5. SIRT5 desuccinylates TBK1 at lysine 137, which leads to TBK1 dephosphorylation and the suppression of the downstream inflammatory pathway. Using SIRT5 lentiviral vectors for skeletal muscle gene therapy in male mice enhances physical performance and alleviates age-related muscle dysfunction. This study sheds light on the molecular underpinnings of skeletal muscle ageing and presents the SIRT5-TBK1 pathway as a promising target for combating age-related skeletal muscle degeneration.

Cxcl9 modulates aging associated microvascular metabolic and angiogenic dysfunctions in subcutaneous adipose tissue

Microvascular aging, predominantly driven by endothelial cells (ECs) dysfunction, is a critical early event in cardiovascular diseases. However, the specific effects of aging on ECs across the microvascular network segments and the associated mechanisms are not fully understood. In this study, we detected a microvascular rarefaction and a decreased proportion of venular ECs in the subcutaneous adipose tissue of aged mice using light-sheet immunofluorescence microscopy and single-cell RNA sequencing. Moreover, aged ECs, especially in the venular subtype, exhibited a pseudotemporal transition to a terminal state characterized by diminished oxidative phosphorylation and strengthened cytokine signaling. Metabolic flux balance analysis predicted that among the 13 differentially expressed cytokines identified in aged EC subpopulations, Cxcl9 was strongly correlated with impaired oxidative phosphorylation in aged ECs. It was further validated using microvascular ECs treated with Cxcl9. Notably, the G protein-coupled receptor signaling pathway was subsequently suppressed, in which Aplnr suppression was also observed in aged ECs, contributing to their impaired energy metabolism and reduced angiogenesis. Based on these findings, we propose Cxcl9 as a biomarker for aging-related dysfunction of microvascular ECs, suggesting that targeting Cxcl9 signaling may help combat microvascular aging.

Protective effects and bioinformatic analysis of narciclasine on vascular aging via cross-talk between inflammation and metabolism through inhibiting skeletal muscle-specific ceramide synthase 1

OBJECTIVE

The senescence of smooth muscle is one of the independent risk factors in atherosclerosis progression in which the vascular inflammation plays an important role on vascular dysfunction. This study is designed to explore the novel vascular aging biomarkers and screen the potential molecular interventional targets through bioinformatic analysis.

RESULTS

Transcriptional analysis was conducted based on the GSE16487 open access database, which included 15 human vascular tissue samples from two groups: young group (≤ 60 years old, n = 8) and aged group (≥ 75 years old, n = 7). There were 275 differential expression genes (119 upregulated and 156 downregulated genes) with minimum 1.5-fold change between two groups. 9 genes were mainly participated in inflammation-related signaling pathways, in which narciclasine was validated as the most effective candidate for modulation the ceramide synthesis. In vitro and animal study demonstrated that narciclasine reversed vascular aging by inhibiting skeletal muscle-specific ceramide synthase 1 (CerS1), reducing the ceramide level derived from CerS1, and improving fat deposition and circulating glycolipid metabolism.

CONCLUSION

Narciclasine attenuates vascular aging and modulates the cross-talk between inflammation and metabolism via inhibiting skeletal muscle-specific ceramide synthase 1.

Transcriptional profile of the rat cardiovascular system at single-cell resolution

We sought to characterize cellular composition across the cardiovascular system of the healthy Wistar rat, an important model in preclinical cardiovascular research. We performed single-nucleus RNA sequencing (snRNA-seq) in 78 samples in 10 distinct regions, including the four chambers of the heart, ventricular septum, sinoatrial node, atrioventricular node, aorta, pulmonary artery, and pulmonary veins, which produced 505,835 nuclei. We identified 26 distinct cell types and additional subtypes, with different cellular composition across cardiac regions and tissue-specific transcription for each cell type. Several cell subtypes were region specific, including a subtype of vascular smooth muscle cells enriched in the large vasculature. We observed tissue-enriched cellular communication networks, including heightened Nppa-Npr1/2/3 signaling in the sinoatrial node. The existence of tissue-restricted cell types suggests regional regulation of cardiovascular physiology. Our detailed transcriptional characterization of each cell type offers the potential to identify novel therapeutic targets and improve preclinical models of cardiovascular disease.

Foxo3-mediated physiological cell competition ensures robust tissue patterning throughout vertebrate development

Unfit cells with defective signalling or gene expression are eliminated through competition with neighbouring cells. However, physiological roles and mechanisms of cell competition in vertebrates remain unclear. In addition, universal mechanisms regulating diverse cell competition are unknown. Using zebrafish imaging, we reveal that cell competition ensures robust patterning of the spinal cord and muscle through elimination of cells with unfit sonic hedgehog activity, driven by cadherin-mediated communication between unfit and neighbouring fit cells and subsequent activation of the Smad-Foxo3-reactive oxygen species axis. We identify Foxo3 as a common marker of loser cells in various types of cell competition in zebrafish and mice. Foxo3-mediated physiological cell competition is required for eliminating various naturally generated unfit cells and for the consequent precise patterning during zebrafish embryogenesis and organogenesis. Given the implication of Foxo3 downregulation in age-related diseases, cell competition may be a defence system to prevent abnormalities throughout development and adult homeostasis.

Perspectives on biomarkers of reproductive aging for fertility and beyond

Reproductive aging, spanning an age-related functional decline in the female and male reproductive systems, compromises fertility and leads to a range of health complications. In this Perspective, we first introduce a comprehensive framework for biomarkers applicable in clinical settings and discuss the existing repertoire of biomarkers used in practice. These encompass functional, imaging-based and biofluid-based biomarkers, all of which reflect the physiological characteristics of reproductive aging and help to determine the reproductive biological age. Next, we delve into the molecular alterations associated with aging in the reproductive system, highlighting the gap between these changes and their potential as biomarkers. Finally, to enhance the precision and practicality of assessing reproductive aging, we suggest adopting cutting-edge technologies for identifying new biomarkers and conducting thorough validations in population studies before clinical applications. These advancements will foster improved comprehension, prognosis and treatment of subfertility, thereby increasing chances of preserving reproductive health and resilience in populations of advanced age.

Comparative single-cell transcriptomic analysis across tissues of aging primates reveals specific autologous activation of ZNF281 to mitigate oxidative stress in cornea

Reactive oxygen species (ROS) and oxidative stress accelerate cellular aging, but their impact on different tissues varies. The cornea, known for its robust antioxidant defense systems, is relatively resistant to age-related diseases like cancer. However, the precise mechanisms by which the cornea maintains ROS homeostasis during aging remain unclear. Through comparative single-cell transcriptomic analysis of the cornea and other tissues in young and old nonhuman primates, we identified that a ZNF281 coding transcriptomic program is specifically activated in cornea during aging. Further investigation revealed that ZNF281 forms a positive feedback loop with FOXO3 to sense elevated levels of ROS and mitigate their effects potentially by regulating the mitochondrial respiratory chain and superoxide dismutase (SOD) expression. Importantly, we observed that overexpression of ZNF281 in MSCs prevented cellular senescence. In summary, these findings open up possibilities for understanding tissue-specific aging and developing new therapies targeting ROS damage.

FOXO3 Longevity Genotype Mitigates Risk Posed by Hypertension on Incident Coronary Artery Disease in Middle-Aged Men: Kuakini Honolulu Heart Program

BACKGROUND

This study tested whether the carriage of the longevity-associated G-allele of FOXO3 SNP rs2802292 (TG/GG) protects against incident coronary artery disease (CAD) in men with hypertension.

METHODS

Subjects were American men residing on Oahu having Japanese (n = 5415) or Okinawan (n = 897) ancestry and free of CAD at baseline (1965-1968) when aged 45-68 years.

RESULTS

During the follow-up, there were 1 629 incident CAD cases. Adjusting for age and cardiovascular disease risk factors, the main effect Cox model showed that in men of Japanese ancestry, hypertension was a strong predictor of CAD (hazard ratio [HR] 1.61; 95% confidence interval [CI] 1.44-1.80), p < .0001), but TG/GG genotype was not associated with CAD (HR 0.92; 95% CI = 0.82-1.02; p = .11). A full Cox model showed the interaction of TG/GG with hypertension was significant (β = -0.23, p = .038). Stratified by hypertension status, TG/GG genotype TG/GG had a protective effect against CAD in each group (HR 0.83; 95% CI 0.71-0.96; p = .021 in men of Japanese heritage, and HR 0.66; 95% CI 0.43-1.01; p = .054 in men of Okinawan heritage). No association with CAD was seen in normotensive men having either Japanese (HR 1.04; 95% CI 0.89-1.22; p = .61) or Okinawan (HR 0.95; 95% CI 0.66-1.38; p = .79) heritage.

CONCLUSIONS

The present prospective study found that longevity-associated FOXO3 genotype did not independently affect the risk of CAD in all men. Rather, it was associated with protection against incident CAD in men with hypertension. Hypertensive middle-aged men with FOXO3TT genotype may merit particular attention in CAD prevention programs.

Investigation of human aging at the single-cell level

Human aging is characterized by a gradual decline in physiological functions and an increased susceptibility to various diseases. The complex mechanisms underlying human aging are still not fully elucidated. Single-cell sequencing (SCS) technologies have revolutionized aging research by providing unprecedented resolution and detailed insights into cellular diversity and dynamics. In this review, we discuss the application of various SCS technologies in human aging research, encompassing single-cell, genomics, transcriptomics, epigenomics, and proteomics. We also discuss the combination of multiple omics layers within single cells and the integration of SCS technologies with advanced methodologies like spatial transcriptomics and mass spectrometry. These approaches have been essential in identifying aging biomarkers, elucidating signaling pathways associated with aging, discovering novel aging cell subpopulations, uncovering tissue-specific aging characteristics, and investigating aging-related diseases. Furthermore, we provide an overview of aging-related databases that offer valuable resources for enhancing our understanding of the human aging process.

Age-Disturbed Vascular Extracellular Matrix Links to Abdominal Aortic Aneurysms

Abdominal aortic aneurysm (AAA) is a common but life-threatening vascular condition in men at an advanced age. However, the underlying mechanisms of age-increased incidence and mortality of AAA remain elusive. Here, we performed RNA sequencing (RNA-seq) of mouse aortas from males (young: 3-month, n = 4 vs old: 23-month, n = 4) and integrated with the data sets of human aortas (young: 20-39, n = 47 vs old: 60-79 years, n = 92) from GTEx project and the data set (GSE183464) for AAA to search for age-shifted aortic aneurysm genes, their relevant biological processes, and signaling pathways. Angiotensin II-induced AAA in mice was used to verify the critical findings. We found 1 001 genes transcriptionally changed with ages in both mouse and human. Most age-increased genes were enriched intracellularly and the relevant biological processes included mitochondrial function and translational controls, whereas the age-decreased genes were largely localized in extracellular regions and cell periphery and the involved biological processes were associated with extracellular matrix (ECM). Fifty-one were known genes for AAA and found dominantly in extracellular region. The common age-shifted vascular genes and known aortic aneurysm genes had shared functional influences on ECM organization, apoptosis, and angiogenesis. Aorta with angiotensin II-induced AAA exhibited similar phenotypic changes in ECM to that in old mice. Together, we present a conserved transcriptional signature for aortic aging and provide evidence that mitochondrial dysfunction and the imbalanced ribosomal homeostasis act likely as driven-forces for aortic aging and age-disturbed ECM is the substrate for developing AAA.

Cardiac Aging in the Multi-Omics Era: High-Throughput Sequencing Insights

Cardiovascular diseases are a leading cause of mortality worldwide, and the risks of both developing a disease and receiving a poor prognosis increase with age. With increasing life expectancy, understanding the mechanisms underlying heart aging has become critical. Traditional techniques have supported research into finding the physiological changes and hallmarks of cardiovascular aging, including oxidative stress, disabled macroautophagy, loss of proteostasis, and epigenetic alterations, among others. The advent of high-throughput multi-omics techniques offers new perspectives on the molecular mechanisms and cellular processes in the heart, guiding the development of therapeutic targets. This review explores the contributions and characteristics of these high-throughput techniques to unraveling heart aging. We discuss how different high-throughput omics approaches, both alone and in combination, produce robust and exciting new findings and outline future directions and prospects in studying heart aging in this new era.

Omics Science and Social Aspects in Detecting Biomarkers for Diagnosis, Risk Prediction, and Outcomes of Carotid Stenosis

Carotid stenosis is characterized by the progressive narrowing of the carotid arteries due to the formation of atherosclerotic plaque, which can lead to stroke and death as major complications. Numerous biomarkers allow for its study and characterization, particularly those related to "omics" sciences. Through the most common research databases, we report representative studies about carotid stenosis biomarkers based on genomics, transcriptomics, proteomics, and metabolomics in a narrative review. To establish a priority among studies based on their internal validity, we used a quality assessment tool, the Scale for the Assessment of Narrative Review Articles (SANRA). Genes, transcriptomes, proteins, and metabolites can diagnose the disease, define plaque connotations, predict consequences after revascularization interventions, and associate carotid stenosis with other patient comorbidities. It also emerged that many aspects determining the patient's psychological and social sphere are implicated in carotid disease. In conclusion, when taking the multidisciplinary approach that combines human sciences with biological sciences, it is possible to comprehensively define a patient's health and thus improve their clinical management through precision medicine.

FAM19A5 in vascular aging and osteoporosis: Mechanisms and the "calcification paradox"

Aging induces a progressive decline in the vasculature's structure and function. Vascular aging is a determinant factor for vascular ailments in the elderly. FAM19A5, a recently identified adipokine, has demonstrated involvement in multiple vascular aging-related pathologies, including atherosclerosis, cardio-cerebral vascular diseases and cognitive deficits. This review summarizes the current understanding of FAM19A5' role and explores its putative regulatory mechanisms in various aging-related disorders, including cardiovascular diseases (CVDs), metabolic diseases, neurodegenerative diseases and malignancies. Importantly, we provide novel insights into the underlying therapeutic value of FAM19A5 in osteoporosis. Finally, we outline future perspectives on the diagnostic and therapeutic potential of FAM19A5 in vascular aging-related diseases.

Single-nucleus transcriptomics uncovers a geroprotective role of YAP in primate gingival aging

Aging has a profound impact on the gingiva and significantly increases its susceptibility to periodontitis, a worldwide prevalent inflammatory disease. However, a systematic characterization and comprehensive understanding of the regulatory mechanism underlying gingival aging is still lacking. Here, we systematically dissected the phenotypic characteristics of gingiva during aging in primates and constructed the first single-nucleus transcriptomic landscape of gingival aging, by which a panel of cell type-specific signatures were elucidated. Epithelial cells were identified as the most affected cell types by aging in the gingiva. Further analyses pinpointed the crucial role of YAP in epithelial self-renew and homeostasis, which declined during aging in epithelial cells, especially in basal cells. The decline of YAP activity during aging was confirmed in the human gingival tissues, and downregulation of YAP in human primary gingival keratinocytes recapitulated the major phenotypic defects observed in the aged primate gingiva while overexpression of YAP showed rejuvenation effects. Our work provides an in-depth understanding of gingival aging and serves as a rich resource for developing novel strategies to combat aging-associated gingival diseases, with the ultimate goal of advancing periodontal health and promoting healthy aging.

Methylation entropy landscape of Chinese long-lived individuals reveals lower epigenetic noise related to human healthy aging

The transition from ordered to noisy is a significant epigenetic signature of aging and age-related disease. As a paradigm of healthy human aging and longevity, long-lived individuals (LLI, >90 years old) may possess characteristic strategies in coping with the disordered epigenetic regulation. In this study, we constructed high-resolution blood epigenetic noise landscapes for this cohort by a methylation entropy (ME) method using whole genome bisulfite sequencing (WGBS). Although a universal increase in global ME occurred with chronological age in general control samples, this trend was suppressed in LLIs. Importantly, we identified 38,923 genomic regions with LLI-specific lower ME (LLI-specific lower entropy regions, for short, LLI-specific LERs). These regions were overrepresented in promoters, which likely function in transcriptional noise suppression. Genes associated with LLI-specific LERs have a considerable impact on SNP-based heritability of some aging-related disorders (e.g., asthma and stroke). Furthermore, neutrophil was identified as the primary cell type sustaining LLI-specific LERs. Our results highlight the stability of epigenetic order in promoters of genes involved with aging and age-related disorders within LLI epigenomes. This unique epigenetic feature reveals a previously unknown role of epigenetic order maintenance in specific genomic regions of LLIs, which helps open a new avenue on the epigenetic regulation mechanism in human healthy aging and longevity.

Cross-species signaling pathways analysis inspire animal model selections for drug screening and target prediction in vascular aging diseases

Age is a significant contributing factor to the occurrence and progression of cardiovascular disease (CVD). Pharmacological treatment can effectively alleviate CVD symptoms caused by aging. However, 90% of the drugs have failed in clinics because of the loss of drug effects or the occurrence of the side effects. One of the reasons is the disparity between animal models used and the actual physiological levels in humans. Therefore, we integrated multiple datasets from single-cell and bulk-seq RNA-sequencing data in rats, monkeys, and humans to identify genes and pathways with consistent/differential expression patterns across these three species. An approach called "Cross-species signaling pathway analysis" was developed to select suitable animal models for drug screening. The effectiveness of this method was validated through the analysis of the pharmacological predictions of four known anti-vascular aging drugs used in animal/clinical experiments. The effectiveness of drugs was consistently observed between the models and clinics when they targeted pathways with the same trend in our analysis. However, drugs might have exhibited adverse effects if they targeted pathways with opposite trends between the models and the clinics. Additionally, through our approach, we discovered four targets for anti-vascular aging drugs, which were consistent with their pharmaceutical effects in literatures, showing the value of this approach. In the end, software was established to facilitate the use of "Cross-species signaling pathway analysis." In sum, our study suggests utilizing bioinformatics analysis based on disease characteristics can help in choosing more appropriate animal models.

Aging hallmarks of the primate ovary revealed by spatiotemporal transcriptomics

The ovary is indispensable for female reproduction, and its age-dependent functional decline is the primary cause of infertility. However, the molecular basis of ovarian aging in higher vertebrates remains poorly understood. Herein, we apply spatiotemporal transcriptomics to benchmark architecture organization as well as cellular and molecular determinants in young primate ovaries and compare these to aged primate ovaries. From a global view, somatic cells within the non-follicle region undergo more pronounced transcriptional fluctuation relative to those in the follicle region, likely constituting a hostile microenvironment that facilitates ovarian aging. Further, we uncovered that inflammation, the senescent-associated secretory phenotype, senescence, and fibrosis are the likely primary contributors to ovarian aging (PCOA). Of note, we identified spatial co-localization between a PCOA-featured spot and an unappreciated MT2 (Metallothionein 2) highly expressing spot (MT2high) characterized by high levels of inflammation, potentially serving as an aging hotspot in the primate ovary. Moreover, with advanced age, a subpopulation of MT2high accumulates, likely disseminating and amplifying the senescent signal outward. Our study establishes the first primate spatiotemporal transcriptomic atlas, advancing our understanding of mechanistic determinants underpinning primate ovarian aging and unraveling potential biomarkers and therapeutic targets for aging and age-associated human ovarian disorders.

A high-resolution view of the heterogeneous aging endothelium

Vascular endothelial cell (EC) aging has a strong impact on tissue perfusion and overall cardiovascular health. While studies confined to the investigation of aging-associated vascular readouts in one or a few tissues have already drastically expanded our understanding of EC aging, single-cell omics and other high-resolution profiling technologies have started to illuminate the intricate molecular changes underlying endothelial aging across diverse tissues and vascular beds at scale. In this review, we provide an overview of recent insights into the heterogeneous adaptations of the aging vascular endothelium. We address critical questions regarding tissue-specific and universal responses of the endothelium to the aging process, EC turnover dynamics throughout lifespan, and the differential susceptibility of ECs to acquiring aging-associated traits. In doing so, we underscore the transformative potential of single-cell approaches in advancing our comprehension of endothelial aging, essential to foster the development of future innovative therapeutic strategies for aging-associated vascular conditions.

Whole organism snRNA-seq reveals systemic peripheral changes in Alzheimer's Disease fly models

Peripheral tissues become disrupted in Alzheimer's Disease (AD). However, a comprehensive understanding of how the expression of AD-associated toxic proteins, Aβ42 and Tau, in neurons impacts the periphery is lacking. Using Drosophila, a prime model organism for studying aging and neurodegeneration, we generated the Alzheimer's Disease Fly Cell Atlas (AD-FCA): whole-organism single-nucleus transcriptomes of 219 cell types from adult flies neuronally expressing human Aβ42 or Tau. In-depth analyses and functional data reveal impacts on peripheral sensory neurons by Aβ42 and on various non-neuronal peripheral tissues by Tau, including the gut, fat body, and reproductive system. This novel AD atlas provides valuable insights into potential biomarkers and the intricate interplay between the nervous system and peripheral tissues in response to AD-associated proteins.

Aging induces region-specific dysregulation of hormone synthesis in the primate adrenal gland

Adrenal glands, vital for steroid secretion and the regulation of metabolism, stress responses and immune activation, experience age-related decline, impacting systemic health. However, the regulatory mechanisms underlying adrenal aging remain largely uninvestigated. Here we established a single-nucleus transcriptomic atlas of both young and aged primate suprarenal glands, identifying lipid metabolism and steroidogenic pathways as core processes impacted by aging. We found dysregulation in centripetal adrenocortical differentiation in aged adrenal tissues and cells in the zona reticularis region, responsible for producing dehydroepiandrosterone sulfate (DHEA-S), were highly susceptible to aging, reflected by senescence, exhaustion and disturbed hormone production. Remarkably, LDLR was downregulated in all cell types of the outer cortex, and its targeted inactivation in human adrenal cells compromised cholesterol uptake and secretion of dehydroepiandrosterone sulfate, as observed in aged primate adrenal glands. Our study provides crucial insights into endocrine physiology, holding therapeutic promise for addressing aging-related adrenal insufficiency and delaying systemic aging.

Age-, sex- and proximal-distal-resolved multi-omics identifies regulators of intestinal aging in non-human primates

The incidence of intestinal diseases increases with age, yet the mechanisms governing gut aging and its link to diseases, such as colorectal cancer (CRC), remain elusive. In this study, while considering age, sex and proximal-distal variations, we used a multi-omics approach in non-human primates (Macaca fascicularis) to shed light on the heterogeneity of intestinal aging and identify potential regulators of gut aging. We explored the roles of several regulators, including those from tryptophan metabolism, in intestinal function and lifespan in Caenorhabditis elegans. Suggesting conservation of region specificity, tryptophan metabolism via the kynurenine and serotonin (5-HT) pathways varied between the proximal and distal colon, and, using a mouse colitis model, we observed that distal colitis was more sensitive to 5-HT treatment. Additionally, using proteomics analysis of human CRC samples, we identified links between gut aging and CRC, with high HPX levels predicting poor prognosis in older patients with CRC. Together, this work provides potential targets for preventing gut aging and associated diseases.

Molecular and Structural Alterations of Skeletal Muscle Tissue Nuclei during Aging

Aging is accompanied by a progressive loss of skeletal muscle mass and strength. The mechanisms underlying this phenomenon are certainly multifactorial and still remain to be fully elucidated. Changes in the cell nucleus structure and function have been considered among the possible contributing causes. This review offers an overview of the current knowledge on skeletal muscle nuclei in aging, focusing on the impairment of nuclear pathways potentially involved in age-related muscle decline. In skeletal muscle two types of cells are present: fiber cells, constituting the contractile muscle mass and containing hundreds of myonuclei, and the satellite cells, i.e., the myogenic mononuclear stem cells occurring at the periphery of the fibers and responsible for muscle growth and repair. Research conducted on different experimental models and with different methodological approaches demonstrated that both the myonuclei and satellite cell nuclei of aged skeletal muscles undergo several structural and molecular alterations, affecting chromatin organization, gene expression, and transcriptional and post-transcriptional activities. These alterations play a key role in the impairment of muscle fiber homeostasis and regeneration, thus contributing to the age-related decrease in skeletal muscle mass and function.

MicroRNAs-associated with FOXO3 in cellular senescence and other stress responses

FOXO3 is a member of the FOXO transcription factor family and is known for regulating cellular survival in response to stress caused by various external and biological stimuli. FOXO3 decides cell fate by modulating cellular senescence, apoptosis and autophagy by transcriptional regulation of genes involved in DNA damage response and oxidative stress resistance. These cellular processes are tightly regulated physiologically, with FOXO3 acting as the hub that integrates signalling networks controlling them. The activity of FOXO3 is influenced by post-translational modifications, altering its subcellular localisation. In addition, FOXO3 can also be regulated directly or indirectly by microRNAs (miRNAs) or vice versa. This review discusses the involvement of various miRNAs in FOXO3-driven cellular responses such as senescence, apoptosis, autophagy, redox and inflammation defence. Given that these responses are linked and influence cell fate, a thorough understanding of the complex regulation by miRNAs would provide key information for developing therapeutic strategy and avoid unintended consequences caused by off-site targeting of FOXO3.

Mapping Cell Atlases at the Single-Cell Level

Recent advancements in single-cell technologies have led to rapid developments in the construction of cell atlases. These atlases have the potential to provide detailed information about every cell type in different organisms, enabling the characterization of cellular diversity at the single-cell level. Global efforts in developing comprehensive cell atlases have profound implications for both basic research and clinical applications. This review provides a broad overview of the cellular diversity and dynamics across various biological systems. In addition, the incorporation of machine learning techniques into cell atlas analyses opens up exciting prospects for the field of integrative biology.

A single-nucleus transcriptomic atlas of primate liver aging uncovers the pro-senescence role of SREBP2 in hepatocytes

Aging increases the risk of liver diseases and systemic susceptibility to aging-related diseases. However, cell type-specific changes and the underlying mechanism of liver aging in higher vertebrates remain incompletely characterized. Here, we constructed the first single-nucleus transcriptomic landscape of primate liver aging, in which we resolved cell type-specific gene expression fluctuation in hepatocytes across three liver zonations and detected aberrant cell-cell interactions between hepatocytes and niche cells. Upon in-depth dissection of this rich dataset, we identified impaired lipid metabolism and upregulation of chronic inflammation-related genes prominently associated with declined liver functions during aging. In particular, hyperactivated sterol regulatory element-binding protein (SREBP) signaling was a hallmark of the aged liver, and consequently, forced activation of SREBP2 in human primary hepatocytes recapitulated in vivo aging phenotypes, manifesting as impaired detoxification and accelerated cellular senescence. This study expands our knowledge of primate liver aging and informs the development of diagnostics and therapeutic interventions for liver aging and associated diseases.

Human ESC-derived vascular cells promote vascular regeneration in a HIF-1α dependent manner

Hypoxia-inducible factor (HIF-1α), a core transcription factor responding to changes in cellular oxygen levels, is closely associated with a wide range of physiological and pathological conditions. However, its differential impacts on vascular cell types and molecular programs modulating human vascular homeostasis and regeneration remain largely elusive. Here, we applied CRISPR/Cas9-mediated gene editing of human embryonic stem cells and directed differentiation to generate HIF-1α-deficient human vascular cells including vascular endothelial cells, vascular smooth muscle cells, and mesenchymal stem cells (MSCs), as a platform for discovering cell type-specific hypoxia-induced response mechanisms. Through comparative molecular profiling across cell types under normoxic and hypoxic conditions, we provide insight into the indispensable role of HIF-1α in the promotion of ischemic vascular regeneration. We found human MSCs to be the vascular cell type most susceptible to HIF-1α deficiency, and that transcriptional inactivation of ANKZF1, an effector of HIF-1α, impaired pro-angiogenic processes. Altogether, our findings deepen the understanding of HIF-1α in human angiogenesis and support further explorations of novel therapeutic strategies of vascular regeneration against ischemic damage.

Extracellular vesicle-derived TP53BP1, CD34, and PBX1 from human peripheral blood serve as potential biomarkers for the assessment and prediction of vascular aging

BACKGROUND

Vascular aging is an important pathophysiological basis for the senescence of various organs and systems in the human body, and it is a common pathogenetic trigger for many chronic diseases in the elderly.

METHODS

The extracellular vesicles (EVs) from young and aged umbilical vein endothelial cells were isolated and identified by qPCR the differential expression levels of 47 mRNAs of genes closely related to aging in the two groups.

RESULTS

There were significant differences in the expression levels of 18 genes (we noted upregulation in PLA2G12A, TP53BP1, CD144, PDE11A, FPGT, SERPINB4, POLD1, and PPFIBP2 and downregulation in ATP2C2, ROBO2, RRM2, GUCY1B1, NAT1-14, VEGFR2, WTAPP1, CD146, DMC1, and GRIK2). Subsequent qPCR identification of the above-mentioned genes in PBMCs and plasma-EVs from the various age groups revealed that the trend in expression levels in peripheral blood plasma-EVs of the different age groups was approximately the same as that in PBMCs. Of these mRNAs, the expression of four genes-PLA2G12A, TP53BP1, OPRL1, and KIAA0895-was commensurate with increasing age. In contradistinction, the expression trend of four genes (CREG1, PBX1, CD34, and SLIT2) was inversely proportional to the increase in age. Finally, by taking their intersection, we determined that the expression of TP53BP1 was upregulated with increasing human age and that CD34 and PBX1 were downregulated with increasing age.

CONCLUSION

Our study indicates that human peripheral blood plasma-EV-derived TP53BP1, CD34, and PBX1 potentially comprise a noninvasive biomarker for assessing and predicting vascular aging.

FOXO3a-regulated arginine metabolic plasticity adaptively promotes esophageal cancer proliferation and metastasis

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor with a poor prognosis due to a lack of early detection. Indeed, the mechanisms underlying ESCC progression remain unclear. Here, we discovered that abnormal arginine metabolism contributes to ESCC progression. Based on transcriptomic and metabolomic analyses, we found that argininosuccinate synthetase 1 (ASS1) and argininosuccinate lyase (ASL) levels were increased in primary tumor tissues but decreased in lymph-metastatic tumor tissues. Intriguingly, FOXO3a was inversely correlated with ASS1 and ASL in primary and metastatic tumor tissues, suggesting that FOXO3a dissimilarly regulates ASS1 and ASL at different stages of ESCC. Silencing ASS1/ASL inhibited primary tumor growth and promoted metastasis. Conversely, overexpression of ASS1/ASL or increased arginine supply promoted tumor proliferation but suppressed metastasis. In addition, FOXO3a activation inhibited primary tumor growth by repressing ASS1 and ASL transcription, whereas inactivation of FOXO3a impeded metastasis by releasing ASS1 and ASL transcription. Together, the finding sheds light on metastatic reprogramming in ESCC.

Transcriptomic Profiling of Reproductive Age Marmoset Monkey Ovaries

The decline in ovarian reserve and the aging of the ovaries is a significant concern for women, particularly in the context of delayed reproduction. However, there are ethical limitations and challenges associated with conducting long-term studies to understand and manipulate the mechanisms that regulate ovarian aging in human. The marmoset monkey offers several advantages as a reproductive model, including a shorter gestation period and similar reproductive physiology to that of human. Additionally, they have a relatively long lifespan compared to other mammals, making them suitable for long-term studies. In this study, we focused on analyzing the structural characteristics of the marmoset ovary and studying the mRNA expression of 244 genes associated with ovarian aging. We obtained ovaries from marmosets at three different reproductive stages: pre-pubertal (1.5 months), reproductive (82 months), and menopausal (106 months) ovaries. The structural analyses revealed the presence of numerous mitochondria and lipid droplets in the marmoset ovaries. Many of the genes expressed in the ovaries were involved in multicellular organism development and transcriptional regulation. Additionally, we identified the expression of protein-binding genes. Within the expressed genes, VEGFA and MMP9 were found to be critical for regulating ovarian reserve. An intriguing finding of the study was the strong correlation between genes associated with female infertility and genes related to fibrosis and wound healing. The authors suggest that this correlation might be a result of the repeated rupture and subsequent healing processes occurring in the ovary due to the menstrual cycle, potentially leading to the indirect onset of fibrosis. The expression profile of ovarian aging-related gene set in the marmoset monkey ovaries highlight the need for further studies to explore the relationship between fibrosis, wound healing, and ovarian aging.

A single-nucleus transcriptomic atlas of primate testicular aging reveals exhaustion of the spermatogonial stem cell reservoir and loss of Sertoli cell homeostasis

The testis is pivotal for male reproduction, and its progressive functional decline in aging is associated with infertility. However, the regulatory mechanism underlying primate testicular aging remains largely elusive. Here, we resolve the aging-related cellular and molecular alterations of primate testicular aging by establishing a single-nucleus transcriptomic atlas. Gene-expression patterns along the spermatogenesis trajectory revealed molecular programs associated with attrition of spermatogonial stem cell reservoir, disturbed meiosis and impaired spermiogenesis along the sequential continuum. Remarkably, Sertoli cell was identified as the cell type most susceptible to aging, given its deeply perturbed age-associated transcriptional profiles. Concomitantly, downregulation of the transcription factor Wilms' Tumor 1 (WT1), essential for Sertoli cell homeostasis, was associated with accelerated cellular senescence, disrupted tight junctions, and a compromised cell identity signature, which altogether may help create a hostile microenvironment for spermatogenesis. Collectively, our study depicts in-depth transcriptomic traits of non-human primate (NHP) testicular aging at single-cell resolution, providing potential diagnostic biomarkers and targets for therapeutic interventions against testicular aging and age-related male reproductive diseases.

Targeting the redox system for cardiovascular regeneration in aging

Cardiovascular aging presents a formidable challenge, as the aging process can lead to reduced cardiac function and heightened susceptibility to cardiovascular diseases. Consequently, there is an escalating, unmet medical need for innovative and effective cardiovascular regeneration strategies aimed at restoring and rejuvenating aging cardiovascular tissues. Altered redox homeostasis and the accumulation of oxidative damage play a pivotal role in detrimental changes to stem cell function and cellular senescence, hampering regenerative capacity in aged cardiovascular system. A mounting body of evidence underscores the significance of targeting redox machinery to restore stem cell self-renewal and enhance their differentiation potential into youthful cardiovascular lineages. Hence, the redox machinery holds promise as a target for optimizing cardiovascular regenerative therapies. In this context, we delve into the current understanding of redox homeostasis in regulating stem cell function and reprogramming processes that impact the regenerative potential of the cardiovascular system. Furthermore, we offer insights into the recent translational and clinical implications of redox-targeting compounds aimed at enhancing current regenerative therapies for aging cardiovascular tissues.

Determining a multimodal aging clock in a cohort of Chinese women

BACKGROUND

Translating aging rejuvenation strategies into clinical practice has the potential to address the unmet needs of the global aging population. However, to successfully do so requires precise quantification of aging and its reversal in a way that encompasses the complexity and variation of aging.

METHODS

Here, in a cohort of 113 healthy women, tiled in age from young to old, we identified a repertoire of known and previously unknown markers associated with age based on multimodal measurements, including transcripts, proteins, metabolites, microbes, and clinical laboratory values, based on which an integrative aging clock and a suite of customized aging clocks were developed.

FINDINGS

A unified analysis of aging-associated traits defined four aging modalities with distinct biological functions (chronic inflammation, lipid metabolism, hormone regulation, and tissue fitness), and depicted waves of changes in distinct biological pathways peak around the third and fifth decades of life. We also demonstrated that the developed aging clocks could measure biological age and assess partial aging deceleration by hormone replacement therapy, a prevalent treatment designed to correct hormonal imbalances.

CONCLUSIONS

We established aging metrics that capture systemic physiological dysregulation, a valuable framework for monitoring the aging process and informing clinical development of aging rejuvenation strategies.

FUNDING

This work was supported by the National Natural Science Foundation of China (32121001), the National Key Research and Development Program of China (2022YFA1103700 and 2020YFA0804000), the National Natural Science Foundation of China (81502304), and the Quzhou Technology Projects (2022K46).

Single-nucleus transcriptome inventory of giant panda reveals cellular basis for fitness optimization under low metabolism

BACKGROUND

Energy homeostasis is essential for the adaptation of animals to their environment and some wild animals keep low metabolism adaptive to their low-nutrient dietary supply. Giant panda is such a typical low-metabolic mammal exhibiting species specialization of extremely low daily energy expenditure. It has low levels of basal metabolic rate, thyroid hormone, and physical activities, whereas the cellular bases of its low metabolic adaptation remain rarely explored.

RESULTS

In this study, we generate a single-nucleus transcriptome atlas of 21 organs/tissues from a female giant panda. We focused on the central metabolic organ (liver) and dissected cellular metabolic status by cross-species comparison. Adaptive expression mode (i.e., AMPK related) was prominently displayed in the hepatocyte of giant panda. In the highest energy-consuming organ, the heart, we found a possibly optimized utilization of fatty acid. Detailed cell subtype annotation of endothelial cells showed the uterine-specific deficiency of blood vascular subclasses, indicating a potential adaptation for a low reproductive energy expenditure.

CONCLUSIONS

Our findings shed light on the possible cellular basis and transcriptomic regulatory clues for the low metabolism in giant pandas and helped to understand physiological adaptation response to nutrient stress.

Aging Biomarker Consortium, Zhang W, Che Y, Tang X, Chen S, Song M, Wang L, Sun AJ, Chen HZ, Xu M, Wang M, Pu J, Li Z, Xiao J, Cao CM, Zhang Y, Lu Y, Zhao Y, Wang YJ, Zhang C, Shen T, Zhang W, Tao L, Qu J, Tang YD, Liu GH, Pei G, Li J, Cao F. A biomarker framework for cardiac aging: the Aging Biomarker Consortium consensus statement

Cardiac aging constitutes a significant risk factor for cardiovascular diseases prevalent among the elderly population. Urgent attention is required to prioritize preventive and management strategies for age-related cardiovascular conditions to safeguard the well-being of elderly individuals. In response to this critical challenge, the Aging Biomarker Consortium (ABC) of China has formulated an expert consensus on cardiac aging biomarkers. This consensus draws upon the latest scientific literature and clinical expertise to provide a comprehensive assessment of biomarkers associated with cardiac aging. Furthermore, it presents a standardized methodology for characterizing biomarkers across three dimensions: functional, structural, and humoral. The functional dimension encompasses a broad spectrum of markers that reflect diastolic and systolic functions, sinus node pacing, neuroendocrine secretion, coronary microcirculation, and cardiac metabolism. The structural domain emphasizes imaging markers relevant to concentric cardiac remodeling, coronary artery calcification, and epicardial fat deposition. The humoral aspect underscores various systemic (N) and heart-specific (X) markers, including endocrine hormones, cytokines, and other plasma metabolites. The ABC's primary objective is to establish a robust foundation for assessing cardiac aging, thereby furnishing a dependable reference for clinical applications and future research endeavors. This aims to contribute significantly to the enhancement of cardiovascular health and overall well-being among elderly individuals.

SIRT2 counteracts primate cardiac aging via deacetylation of STAT3 that silences CDKN2B

Aging is a major risk factor contributing to pathophysiological changes in the heart, yet its intrinsic mechanisms have been largely unexplored in primates. In this study, we investigated the hypertrophic and senescence phenotypes in the hearts of aged cynomolgus monkeys as well as the transcriptomic and proteomic landscapes of young and aged primate hearts. SIRT2 was identified as a key protein decreased in aged monkey hearts, and engineered SIRT2 deficiency in human pluripotent stem cell-derived cardiomyocytes recapitulated key senescence features of primate heart aging. Further investigations revealed that loss of SIRT2 in human cardiomyocytes led to the hyperacetylation of STAT3, which transcriptionally activated CDKN2B and, in turn, triggered cardiomyocyte degeneration. Intra-myocardial injection of lentiviruses expressing SIRT2 ameliorated age-related cardiac dysfunction in mice. Taken together, our study provides valuable resources for decoding primate cardiac aging and identifies the SIRT2-STAT3-CDKN2B regulatory axis as a potential therapeutic target against human cardiac aging and aging-related cardiovascular diseases.

Decoding Aging Hallmarks at the Single-Cell Level

Organismal aging exhibits wide-ranging hallmarks in divergent cell types across tissues, organs, and systems. The advancement of single-cell technologies and generation of rich datasets have afforded the scientific community the opportunity to decode these hallmarks of aging at an unprecedented scope and resolution. In this review, we describe the technological advancements and bioinformatic methodologies enabling data interpretation at the cellular level. Then, we outline the application of such technologies for decoding aging hallmarks and potential intervention targets and summarize common themes and context-specific molecular features in representative organ systems across the body. Finally, we provide a brief summary of available databases relevant for aging research and present an outlook on the opportunities in this emerging field.

HCV Core Protein-ISX Axis Promotes Chronic Liver Disease Progression via Metabolic Remodeling and Immune Suppression

Chronic hepatitis C virus (HCV) infection is an important public health issue. However, knowledge on how the virus remodels the metabolic and immune response toward hepatic pathologic environment is limited. The transcriptomic and multiple evidences reveal that the HCV core protein-intestine-specific homeobox (ISX) axis promotes a spectrum of metabolic, fibrogenic, and immune modulators (e.g., kynurenine, PD-L1, and B7-2), regulating HCV-infection relevant pathogenic phenotype in vitro and in vivo. In a transgenic mice model, the HCV core protein-ISX axis enhance metabolic disturbance (particularly lipid and glucose metabolism) and immune suppression, and finally, chronic liver fibrosis in a high-fat diet (HFD)-induced disease model. Mechanistically, cells with HCV JFH-1 replicons upregulate ISX and, consequently, the expressions of metabolic, fibrosis progenitor, and immune modulators via core protein-induced nuclear factor-κB signaling. Conversely, cells with specific ISX shRNAi inhibit HCV core protein-induced metabolic disturbance and immune suppression. Clinically, the HCV core level is significantly correlated with ISX, IDOs, PD-L1, and B7-2 levels in HCC patients with HCV infection. Therefore, it highlights the significance of HCV core protein-ISX axis as an important mechanism in the development of HCV-induced chronic liver disease and can be a specific therapeutic target clinically.

Aging Biomarker Consortium, Zhang L, Guo J, Liu Y, Sun S, Liu B, Yang Q, Tao J, Tian XL, Pu J, Hong H, Wang M, Chen HZ, Ren J, Wang X, Liang Z, Wang Y, Huang K, Zhang W, Qu J, Ju Z, Liu GH, Pei G, Li J, Zhang C. A framework of biomarkers for vascular aging: a consensus statement by the Aging Biomarker Consortium

Aging of the vasculature, which is integral to the functioning of literally all human organs, serves as a fundamental physiological basis for age-related alterations as well as a shared etiological mechanism for various chronic diseases prevalent in the elderly population. China, home to the world's largest aging population, faces an escalating challenge in addressing the prevention and management of these age-related conditions. To meet this challenge, the Aging Biomarker Consortium of China has developed an expert consensus on biomarkers of vascular aging (VA) by synthesizing literature and insights from scientists and clinicians. This consensus provides a comprehensive assessment of biomarkers associated with VA and presents a systemic framework to classify them into three dimensions: functional, structural, and humoral. Within each dimension, the expert panel recommends the most clinically relevant VA biomarkers. For the functional domain, biomarkers reflecting vascular stiffness and endothelial function are highlighted. The structural dimension encompasses metrics for vascular structure, microvascular structure, and distribution. Additionally, proinflammatory factors are emphasized as biomarkers with the humoral dimension. The aim of this expert consensus is to establish a foundation for assessing the extent of VA and conducting research related to VA, with the ultimate goal of improving the vascular health of the elderly in China and globally.

Human and murine fibroblast single-cell transcriptomics reveals fibroblast clusters are differentially affected by ageing and serum cholesterol

AIMS

Specific fibroblast markers and in-depth heterogeneity analysis are currently lacking, hindering functional studies in cardiovascular diseases (CVDs). Here, we established cell-type markers and heterogeneity in murine and human arteries and studied the adventitial fibroblast response to CVD and its risk factors hypercholesterolaemia and ageing.

METHODS AND RESULTS

Murine aorta single-cell RNA-sequencing analysis of adventitial mesenchymal cells identified fibroblast-specific markers. Immunohistochemistry and flow cytometry validated platelet-derived growth factor receptor alpha (PDGFRA) and dipeptidase 1 (DPEP1) across human and murine aorta, carotid, and femoral arteries, whereas traditional markers such as the cluster of differentiation (CD)90 and vimentin also marked transgelin+ vascular smooth muscle cells. Next, pseudotime analysis showed multiple fibroblast clusters differentiating along trajectories. Three trajectories, marked by CD55 (Cd55+), Cxcl chemokine 14 (Cxcl14+), and lysyl oxidase (Lox+), were reproduced in an independent RNA-seq dataset. Gene ontology (GO) analysis showed divergent functional profiles of the three trajectories, related to vascular development, antigen presentation, and/or collagen fibril organization, respectively. Trajectory-specific genes included significantly more genes with known genome-wide associations (GWAS) to CVD than expected by chance, implying a role in CVD. Indeed, differential regulation of fibroblast clusters by CVD risk factors was shown in the adventitia of aged C57BL/6J mice, and mildly hypercholesterolaemic LDLR KO mice on chow by flow cytometry. The expansion of collagen-related CXCL14+ and LOX+ fibroblasts in aged and hypercholesterolaemic aortic adventitia, respectively, coincided with increased adventitial collagen. Immunohistochemistry, bulk, and single-cell transcriptomics of human carotid and aorta specimens emphasized translational value as CD55+, CXCL14+ and LOX+ fibroblasts were observed in healthy and atherosclerotic specimens. Also, trajectory-specific gene sets are differentially correlated with human atherosclerotic plaque traits.

CONCLUSION

We provide two adventitial fibroblast-specific markers, PDGFRA and DPEP1, and demonstrate fibroblast heterogeneity in health and CVD in humans and mice. Biological relevance is evident from the regulation of fibroblast clusters by age and hypercholesterolaemia in vivo, associations with human atherosclerotic plaque traits, and enrichment of genes with a GWAS for CVD.

Nuclear lamina erosion-induced resurrection of endogenous retroviruses underlies neuronal aging

The primate frontal lobe (FL) is sensitive to aging-related neurocognitive decline. However, the aging-associated molecular mechanisms remain unclear. Here, using physiologically aged non-human primates (NHPs), we depicted a comprehensive landscape of FL aging with multidimensional profiling encompassing bulk and single-nucleus transcriptomes, quantitative proteome, and DNA methylome. Conjoint analysis across these molecular and neuropathological layers underscores nuclear lamina and heterochromatin erosion, resurrection of endogenous retroviruses (ERVs), activated pro-inflammatory cyclic GMP-AMP synthase (cGAS) signaling, and cellular senescence in post-mitotic neurons of aged NHP and human FL. Using human embryonic stem-cell-derived neurons recapitulating cellular aging in vitro, we verified the loss of B-type lamins inducing resurrection of ERVs as an initiating event of the aging-bound cascade in post-mitotic neurons. Of significance, these aging-related cellular and molecular changes can be alleviated by abacavir, a nucleoside reverse transcriptase inhibitor, either through direct treatment of senescent human neurons in vitro or oral administration to aged mice.