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

S100A11 is a potential prognostic biomarker and correlated with tumor immunosuppressive microenvironment in glioma

BACKGROUND

This study investigates the role of S100A11 as a potential biomarker for glioma-associated macrophages (GAMs) and its correlation with GAMs infiltration in glioblastoma multiforme, aiming to better understand the immune microenvironment of glioma.

METHODS

We conducted a comprehensive study using various techniques and approaches. First, we examined the expression of S100A11 on GAMs through Western blot, immunohistochemistry, and immunofluorescence analyses. Additionally, we utilized single-cell sequencing data and immune infiltration analysis to establish the relationship between S100A11 and GAMs infiltration in glioma.

RESULTS

Our findings revealed that S100A11 was highly expressed on GAMs, as validated by Western blot, immunohistochemistry, and immunofluorescence. Moreover, S100A11 exhibited a strong correlation with GAMs infiltration, as evidenced by single-cell data and immune infiltration analysis. These results highlight the significant association of S100A11 with the immune microenvironment surrounding glioma.

CONCLUSION

S100A11 emerges as a promising candidate for regulating glioma immunosuppression and may serve as a potential marker for GAMs. This study sheds light on the crucial role of S100A11 in the crosstalk between GAMs and glioma cells, contributing to our understanding of glioma progression within the tumor microenvironment.

A chimeric peptide promotes immune surveillance of senescent cells in injury, fibrosis, tumorigenesis and aging

The accumulation of senescent cells can lead to tissue degeneration, chronic inflammatory disease and age-related tumorigenesis. Interventions such as senolytics are currently limited by off-target toxicity, which could be circumvented by instead enhancing immune-mediated senescent cell clearance; however, immune surveillance of senescent cells is often impeded by immunosuppressive factors in the inflammatory microenvironment. Here, we employ a chimeric peptide as a 'matchmaker' to bind to the urokinase-type plasminogen activator receptor, a cell surface marker of senescent cells. This peptide modifies the cell surface with polyglutamic acid, promoting immune cell-mediated responses through glutamate recognition. By enhancing the recruitment of immune cells and directly coupling senescent cells and immune cells, we show that this chimeric peptide induces immune clearance of senescent cells and restores tissue homeostasis in conditions such as liver fibrosis, lung injury, cancer and natural aging in mice. This chimeric peptide introduces an immunological conversion strategy that rebalances the senescent immune microenvironment, offering a promising direction for aging immunotherapy.

Roles of chromatin and genome instability in cellular senescence and their relevance to ageing and related diseases

Ageing is a complex biological process in which a gradual decline in physiological fitness increases susceptibility to diseases such as neurodegenerative disorders and cancer. Cellular senescence, a state of irreversible cell-growth arrest accompanied by functional deterioration, has emerged as a pivotal driver of ageing. In this Review, we discuss how heterochromatin loss, telomere attrition and DNA damage contribute to cellular senescence, ageing and age-related diseases by eliciting genome instability, innate immunity and inflammation. We also discuss how emerging therapeutic strategies could restore heterochromatin stability, maintain telomere integrity and boost the DNA repair capacity, and thus counteract cellular senescence and ageing-associated pathologies. Finally, we outline current research challenges and future directions aimed at better comprehending and delaying ageing.

Mapping the evolution of liver aging research: A bibliometric analysis

BACKGROUND

With the increasing of the global aging population, healthy aging and prevention of age-related diseases have become increasingly important. The liver, a vital organ involved in metabolism, detoxification, digestion, and immunity, holds a pivotal role in the aging process of organisms. Although extensive research on liver aging has been carried out, no bibliometric analysis has been conducted to evaluate the scientific progress in this area.

AIM

To analyze basic knowledge, development trends, and current research frontiers in the field via bibliometric methods.

METHODS

We conducted bibliometric analyses via a range of analytical tools including Python, the bibliometrix package in R, CiteSpace, and VOSviewer. We retrieved publication data on liver aging research from the Web of Science Core Collection Database. A scientific knowledge map was constructed to display the contributions from different authors, journals, countries, institutions, as well as patterns of co-occurrence keywords and co-cited references. Additionally, gene regulation pathways associated with liver aging were analyzed via the STRING database.

RESULTS

We identified 4288 articles on liver aging, authored by 24034 contributors from 4092 institutions across 85 countries. Notably, the years 1991 and 2020 presented significant bursts in publication output. The United States led in terms of publications (n = 1008, 25.1%), citations (n = 55205), and international collaborations (multiple country publications = 214). Keywords such as "lipid metabolism", "fatty liver disease", "inflammation", "liver fibrosis" and "target" were prominent, highlighting the current research hotspots. Notably, the top 64 genes, each of which appeared in at least 8 articles, were involved in pathways essential for cell survival and aging, including the phosphatidylinositol 3-kinase/protein kinase B, Forkhead box O and p53 signaling pathways.

CONCLUSION

This study highlights key areas of liver aging and offers a comprehensive overview of research trends, as well as insights into potential value for collaborative pursuits and clinical implementations.

Metformin decelerates aging clock in male monkeys

In a rigorous 40-month study, we evaluated the geroprotective effects of metformin on adult male cynomolgus monkeys, addressing a gap in primate aging research. The study encompassed a comprehensive suite of physiological, imaging, histological, and molecular evaluations, substantiating metformin's influence on delaying age-related phenotypes at the organismal level. Specifically, we leveraged pan-tissue transcriptomics, DNA methylomics, plasma proteomics, and metabolomics to develop innovative monkey aging clocks and applied these to gauge metformin's effects on aging. The results highlighted a significant slowing of aging indicators, notably a roughly 6-year regression in brain aging. Metformin exerts a substantial neuroprotective effect, preserving brain structure and enhancing cognitive ability. The geroprotective effects on primate neurons were partially mediated by the activation of Nrf2, a transcription factor with anti-oxidative capabilities. Our research pioneers the systemic reduction of multi-dimensional biological age in primates through metformin, paving the way for advancing pharmaceutical strategies against human aging.

Deciphering STAT3's negative regulation of LHPP in ESCC progression through single-cell transcriptomics analysis

BACKGROUND

Esophageal Squamous Cell Carcinoma (ESCC) remains a predominant health concern in the world, characterized by high prevalence and mortality rates. Advances in single-cell transcriptomics have revolutionized cancer research by enabling a precise dissection of cellular and molecular diversity within tumors.

OBJECTIVE

This study aims to elucidate the cellular dynamics and molecular mechanisms in ESCC, focusing on the transcriptional influence of STAT3 (Signal Transducer and Activator of Transcription 3) and its interaction with LHPP, thereby uncovering potential therapeutic targets.

METHODS

Single-cell RNA sequencing was employed to analyze 44,206 cells from tumor and adjacent normal tissues of ESCC patients, identifying distinct cell types and their transcriptional shifts. We conducted differential gene expression analysis to assess changes within the tumor microenvironment (TME). Validation of key regulatory interactions was performed using qPCR in a cohort of 21 ESCC patients and further substantiated through experimental assays in ESCC cell lines.

RESULTS

The study revealed critical alterations in cell composition and gene expression across identified cell populations, with a notable shift towards pro-tumorigenic states. A significant regulatory influence of STAT3 on LHPP was discovered, establishing a novel aspect of ESCC pathogenesis. Elevated levels of STAT3 and suppressed LHPP expression were validated in clinical samples. Functional assays confirmed that STAT3 directly represses LHPP at the promoter level, and disruption of this interaction by promoter mutations diminished STAT3's repressive effect.

CONCLUSION

This investigation underscores the central role of STAT3 as a regulator in ESCC, directly impacting LHPP expression and suggesting a regulatory loop crucial for tumor behavior. The insights gained from our comprehensive cellular and molecular analysis offer a deeper understanding of the dynamics within the ESCC microenvironment. These findings pave the way for targeted therapeutic interventions focusing on the STAT3-LHPP axis, providing a strategic approach to improve ESCC management and prognosis.

The preparation, modification and hepatoprotective activity of chitooligosaccharides: A review

Chitooligosaccharides (COS) has attracted increasing attention due to the various promising bioactivities, tremendous potential in agricultural, environmental nutritional and functional food fields. COS as the major degradation product from chitosan or chitin is prepared via enzymatic, chemical and physical methods. Further obtained COS generally possesses different structural characteristics, such as molecular weight, degree of acetylation and degree of polymerization. Innovations into COS modification has also broadened application of COS in nutrition as well as in agricultural safety. Due to the affinity between structure and bioactivity, diversity of structural characteristics endows COS with various bioactivities like antitumor, antioxidant and anti-inflammatory effects, especially hepatoprotective activity. Therefore, the present review narrates the recent developments in COS physicochemical properties, while paying considerable attention to preparation strategies of COS and their advantages and disadvantages. Moreover, the modification of COS is also discussed including alkylation, quaternization and sulfation, herein the structure-activity relationship of COS was highlighted. Additionally, we summarize the latest research on hepatoprotective activity and mechanisms of COS. Eventually, the future directions of research on COS were discussed, which would provide a new appreciation for the future use of COS.

Exploring the heterogeneous targets of metabolic aging at single-cell resolution

Our limited understanding of metabolic aging poses major challenges to comprehending the diverse cellular alterations that contribute to age-related decline, and to devising targeted interventions. This review provides insights into the heterogeneous nature of cellular metabolism during aging and its response to interventions, with a specific focus on cellular heterogeneity and its implications. By synthesizing recent findings using single-cell approaches, we explored the vulnerabilities of distinct cell types and key metabolic pathways. Delving into the cell type-specific alterations underlying the efficacy of systemic interventions, we also discuss the complexity of integrating single-cell data and advocate for leveraging computational tools and artificial intelligence to harness the full potential of these data, develop effective strategies against metabolic aging, and promote healthy aging.

Does the liver facilitate aging-related cognitive impairment: Conversation between liver and brain during exercise?

Liver, an important regulator of metabolic homeostasis, is critical for healthy brain function. In particular, age-related neurodegenerative diseases seriously reduce the quality of life for the elderly. As population aging progresses rapidly, unraveling the mechanisms that effectively delay aging has become critical. Appropriate exercise is reported to improve aging-related cognitive impairment. Whereas current studies focused on exploring the effect of exercise on the aging brain itself, ignoring the persistent effects of peripheral organs on the brain through the blood circulation. The aim of this paper is to summarize the communication and aging processes of the liver and brain and to emphasize the metabolic mechanisms of the liver-brain axis about exercise ameliorating aging-related neurodegenerative diseases. A comprehensive understanding of the potential mechanisms about exercise ameliorating aging is critical for improving adaptation to age-related brain changes and formulating effective interventions against age-related cognitive decline.

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.

Endogenous retroviruses in development and health

Endogenous retroviruses (ERVs) are evolutionary remnants of retroviral infections in which the viral genome became embedded as a dormant regulatory element within the host germline. When ERVs become activated, they comprehensively rewire genomic regulatory networks of the host and facilitate critical developmental events, such as preimplantation development and placentation, in a manner specific to species, developmental stage, and tissues. However, accumulating evidence suggests that aberrant ERV transcription compromises genome stability and has been implicated in cellular senescence and various pathogenic processes, underscoring the significance of host genomic surveillance mechanisms. Here, we revisit the prominent functions of ERVs in early development and highlight their emerging roles in mammalian post-implantation development and organogenesis. We also discuss their implications for aging and pathological processes such as microbial infection, immune response. Furthermore, we discuss recent advances in stem-cell-based models, single-cell omics, and genome editing technologies, which serve as beacons illuminating the versatile nature of ERVs in mammalian development and health.

5-Heptadecylresorcinol Improves Aging-Associated Hepatic Fatty Acid Oxidation Dysfunction via Regulating Adipose Sirtuin 3

Aging-associated hepatic fatty acid (FA) oxidation dysfunction contributes to impaired adaptive thermogenesis. 5-Heptadecylresorcinol (AR-C17) is a prominent functional component of whole wheat and rye, and has been demonstrated to improve the thermogenic capacity of aged mice via the regulation of Sirt3. However, the effect of AR-C17 on aging-associated hepatic FA oxidation dysfunction remains unclear. Here, 18-month-old C57BL/6J mice were orally administered with AR-C17 at a dose of 150 mg/kg/day for 8 weeks. Systemic glucose and lipid metabolism, hepatic FA oxidation, and the lipolysis of white adipose tissues (WAT) were measured. The results showed that AR-C17 improved the hepatic FA oxidation, and especially acylcarnitine metabolism, of aged mice during cold stimulation, with the enhancement of systemic glucose and lipid metabolism. Meanwhile, AR-C17 improved the WAT lipolysis of aged mice, promoting hepatic acylcarnitine production. Furthermore, the adipose-specific Sirt3 knockout mice were used to investigate and verify the regulation mechanism of AR-C17 on aging-associated hepatic FA oxidation dysfunction. The results showed that AR-C17 failed to improve the WAT lipolysis and hepatic FA oxidation of aged mice in the absence of adipose Sirt3, indicating that AR-C17 might indirectly influence hepatic FA oxidation via regulating WAT Sirt3. Our findings suggest that AR-C17 might improve aging-associated hepatic FA oxidation dysfunction via regulating adipose Sirt3.

Multimodal Omics Approaches to Aging and Age-Related Diseases

Aging is associated with a progressive decline in physiological capacities and an increased risk of aging-associated disorders. An increasing body of experimental evidence shows that aging is a complex biological process coordinately regulated by multiple factors at different molecular layers. Thus, it is difficult to delineate the overall systematic aging changes based on single-layer data. Instead, multimodal omics approaches, in which data are acquired and analyzed using complementary omics technologies, such as genomics, transcriptomics, and epigenomics, are needed for gaining insights into the precise molecular regulatory mechanisms that trigger aging. In recent years, multimodal omics sequencing technologies that can reveal complex regulatory networks and specific phenotypic changes have been developed and widely applied to decode aging and age-related diseases. This review summarizes the classification and progress of multimodal omics approaches, as well as the rapidly growing number of articles reporting on their application in the field of aging research, and outlines new developments in the clinical treatment of age-related diseases based on omics technologies.

Hepatocyte reprogramming in liver regeneration: Biological mechanisms and applications

The liver is one of the few organs that retain the capability to regenerate in adult mammals. This regeneration process is mainly facilitated by the dynamic behavior of hepatocytes, which are the major functional constituents in the liver. In response to liver injury, hepatocytes undergo remarkable alterations, such as reprogramming, wherein they lose their original identity and acquire properties from other cells. This phenomenon of hepatocyte reprogramming, coupled with hepatocyte expansion, plays a central role in liver regeneration, and its underlying mechanisms are complex and multifaceted. Understanding the fate of reprogrammed hepatocytes and the mechanisms of their conversion has significant implications for the development of innovative therapeutics for liver diseases. Herein, we review the plasticity of hepatocytes in response to various forms of liver injury, with a focus on injury-induced hepatocyte reprogramming. We provide a comprehensive summary of current knowledge on the molecular and cellular mechanisms governing hepatocyte reprogramming, specifically in the context of liver regeneration, providing insight into potential applications of this process in the treatment of liver disorders, including chronic liver diseases and liver cancer.

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).

Genome-wide CRISPR activation screening in senescent cells reveals SOX5 as a driver and therapeutic target of rejuvenation

Our understanding of the molecular basis for cellular senescence remains incomplete, limiting the development of strategies to ameliorate age-related pathologies by preventing stem cell senescence. Here, we performed a genome-wide CRISPR activation (CRISPRa) screening using a human mesenchymal precursor cell (hMPC) model of the progeroid syndrome. We evaluated targets whose activation antagonizes cellular senescence, among which SOX5 outperformed as a top hit. Through decoding the epigenomic landscapes remodeled by overexpressing SOX5, we uncovered its role in resetting the transcription network for geroprotective genes, including HMGB2. Mechanistically, SOX5 binding elevated the enhancer activity of HMGB2 with increased levels of H3K27ac and H3K4me1, raising HMGB2 expression so as to promote rejuvenation. Furthermore, gene therapy with lentiviruses carrying SOX5 or HMGB2 rejuvenated cartilage and alleviated osteoarthritis in aged mice. Our study generated a comprehensive list of rejuvenators, pinpointing SOX5 as a potent driver for rejuvenation both in vitro and in vivo.