A synopsis on aging-Theories, mechanisms and future prospects

Osteoarthritis as an evolutionary legacy: Biological ageing and chondrocyte hypertrophy

Objective

Osteoarthritis (OA) is a progressive joint disease habitually linked to ageing, characterized by the gradual breakdown of cartilage leading to pain and reduced mobility. Historically viewed as mainly a "wear and tear" condition, new insights suggest that OA may be part of an evolutionary, age-related biological process rather than mainly driven by mechanical damage.

Design

This conceptual paper discusses the model of antagonistic pleiotropy that proposes that certain genes beneficial early in life may contribute to diseases in the context of OA.

Results

Findings indicate that OA is connected to biological and not to chronological age supporting the idea that OA is not merely a wear and tear process. Chondrocyte hypertrophy, essential in endochondral bone formation at a (pre)reproductive age, is stimulated by a displaced and wrongly timed endochondral ossification quasi-program in age-related OA. Age-related chondrocyte hypertrophic differentiation in articular cartilage is likely driven by loss of loading-induced TGF-β signaling.

Conclusion

Comprehending OA within this evolutionary and biological frame provides a solid alternative to the theory of "wear and tear", offering insights into further understanding, prevention and disease management.

Clinical application of mesenchymal stem cells in immunosenescence: a qualitative review of their potential and challenges

Aging leads to a gradual decline in immune function, termed immunosenescence, which significantly elevates the susceptibility to infections, cancers, and other aging-related diseases. Recent advancements have shed light on the molecular underpinnings of immune aging and pioneered novel therapeutic interventions to counteract its effects. Mesenchymal stem cells (MSCs)-a type of multipotent stromal cells with regenerative potential, low immunogenicity, and strong immunomodulatory properties-are increasingly recognized as a promising therapeutic option to reverse or alleviate immunosenescence-related dysfunction. This review systematically summarizes recent discoveries on how MSCs counteract immune aging, particularly their ability to rejuvenate aged immune cells and restore immune homeostasis. It also addresses key challenges, such as variations in MSC sources, donor variability, and the lack of standardized protocols, while proposing future directions to enhance therapeutic precision. Although preclinical and clinical studies highlight the potential of MSC-based strategies for delaying immunosenescence, critical issues remain unresolved, including long-term safety and efficacy, optimizing cell delivery systems, and elucidating context-specific mechanisms. Addressing these challenges will accelerate the development of MSC-based therapies to combat aging-associated immune decline.

Avoiding Functional Decline and Minimizing the Effects of Frailty in Hospitalized Older Adults

PURPOSE/OBJECTIVES

The purpose of this article is to introduce the clinical nurse specialist to the Frailty Care Model. This model can be used by the clinical nurse specialist as a framework to guide nurses as they provide care to older adults predisposed to frailty progression while hospitalized.

DESCRIPTION

The Frailty Care Model is used as a framework to plan the care of the hospitalized older adult. Examples of frailty screening tools are presented to inform the clinical nurse specialist of the older adult's needs for intervention while hospitalized, and a case study is used. Known targets for frailty interventions include low physical activity, malnutrition, and depression, and recommendations for each are given.

OUTCOME

The clinical nurse specialist can use and support specific interventions to improve mobility and physical activity, address depression, and improve nutritional intake in hospitalized older adults.

CONCLUSION

The clinical nurse specialist is essential to the care of the hospitalized older adult who has frailty or is at risk for frailty. Frailty screening and an awareness of risks as well as modifiable factors can set the stage for supportive care that can help to prevent or stabilize frailty in the hospitalized older adult.

The Predictive Capacity of the 3-Meter Backward Walk Test for Falls in Older Adults: A Case-Control Analysis

Background: The early detection of fall risk in older adults is crucial for prevention. This study assessed the 3-Meter Backward Walk Test (3m-BWT) as a predictor of falls. Methods: A retrospective observational case-control study was conducted with 483 community-dwelling participants (mean age 76.3 ± 6.5 years), including 101 individuals with a history of falls in the previous 12 months. A standardized battery of functional assessments was applied. Results: Significant differences were observed between fallers and non-fallers across all functional variables (p < 0.001), with fallers demonstrating slower performance on the 3m-BWT (6.8 ± 3.4 s vs. 5.1 ± 1.3 s). The 3m-BWT showed moderate correlations with Short Physical Performance Battery, 5-repetition Sit-to-Stand, gait speed, and 4-Square Step Test, and a moderate-to-strong correlation with Timed Up-and-Go (r = 0.632), even after adjusting for age, sex, and BMI. Although the 3m-BWT exhibited superior discriminative ability compared to other tests (AUC = 0.655), its predictive power in isolation remains limited. The optimal cut-off point was identified at 5.5 s (sensitivity: 59.5%; specificity: 68.6%), while a threshold of <3.5 s yielded high sensitivity (98%) but low specificity, supporting its use in fall risk screening. Conclusions: These findings support the integration of the 3m-BWT as a complementary tool within comprehensive geriatric assessments, particularly in contexts requiring high sensitivity. Given the multifactorial nature of falls, combining the 3m-BWT with other clinical evaluations and fall history is recommended to enhance risk stratification and inform preventive strategies.

Immunotherapeutic targeting of aging-associated isoDGR motif in chronic lung inflammation

Accumulation of damaged biomolecules in body tissues is the primary cause of aging and age-related chronic diseases. Since this damage often occurs spontaneously, it has traditionally been regarded as untreatable, with typical therapeutic strategies targeting genes or enzymes being ineffective in this domain. In this report, we demonstrate that an antibody targeting the isoDGR damage motif in lung tissue can guide immune clearance of harmful damaged proteins in vivo, effectively reducing age-linked lung inflammation. We observed age-dependent accumulation of the isoDGR motif in human lung tissues, as well as an 8-fold increase in isoDGR-damaged proteins in lung fibrotic tissues compared with healthy tissue. This increase was accompanied by marked infiltration of CD68+/CD11b + macrophages, consistent with a role for isoDGR in promoting chronic inflammation. We therefore assessed isoDGR function in mice that were either naturally aged or lacked the isoDGR repair enzyme. IsoDGR-protein accumulation in mouse lung tissue was strongly correlated with chronic inflammation, pulmonary edema, and hypoxemia. This accumulation also induced mitochondrial and ribosomal dysfunction, in addition to features of cellular senescence, thereby contributing to progressive lung damage over time. Importantly, treatment with anti-isoDGR antibody was able to reduce these molecular features of disease and significantly reduced lung pathology in vivo.

Towards a holistic approach to pulmonary infections. Insights from the Sixth Annual Meeting of Spanish Experts 2024

Pneumonia is the leading cause of death from infection in the developed world. In recent years, researchers and healthcare professionals have worked extensively to reduce this burden. Prevention is better than cure, and significant advances have been made in areas such as vaccination and the prevention of nosocomial pneumonia in intensive care units. Comprehensive surveillance programmes and new diagnostic methods have been developed to assess trends in this disease and to identify the infectious agents involved. Clinical presentation can be challenging in elderly patients or those with certain comorbidities, prompting new studies in these populations to address these issues. Correct and early management of severe community-acquired pneumonia represents a major opportunity to reduce its associated mortality. Although fungal pathogens are an uncommon cause of lung infection, they are associated with high morbidity and mortality, highlighting the need for new approaches. Finally, new drugs are available for the treatment of pneumonia, and a thorough understanding of them is key to ensuring their correct use, particularly to combat multi-resistance. To provide an update on these points, a multidisciplinary team of Spanish experts convened at the Sixth Annual Meeting of Pneumonia Day, under the scientific sponsorship of GEIPC-SEIMC. This paper reflects the information shared at this meeting, offering the latest insights on these topics and supporting a holistic approach to pneumonia management.

Coenzyme Q10 supplementation affects cellular ionic balance: relevance to aging

Aging results into disruptive physiological functioning and cellular processes that affect the composition and structure of the plasma membrane. The plasma membrane is the major regulator of ionic homeostasis that regulates the functioning of membrane transporters and exchangers. Coenzyme Q10 is a lipid-soluble antioxidant molecule that declines during aging and age-associated diseases. The present study aims to explore the role of Coenzyme Q10 supplementation to rats during aging on membrane transporters and redox biomarkers. The study was conducted on young and old male Wistar rats supplemented with 20 mg/kg b.w. of Coenzyme Q10 per day. After a period of 28 days, rats were sacrificed and erythrocyte membrane was isolated. The result exhibits significant decline in biomarkers of oxidative stress in old control rats when compared with young control. The effect of Coenzyme Q10 supplementation was more pronounced in old rats. The functioning of membrane transporters and Na+/H+ exchanger showed potential return to normal levels in the Coenzyme Q10 treated rats. Overall, the results demonstrate that Coenzyme Q10 plays an important role in maintaining redox balance in cells which interconnects with membrane integrity. Thus, Coenzyme Q10 supplementation may play an important role in protecting age related alterations in erythrocyte membrane physiology.

Evaluation of Anti-aging Agents Using the D-Galactose-Induced Accelerated Aging Model

The aging population is rapidly increasing, emphasizing the importance of understanding aging mechanisms and developing effective anti-aging therapies. This chapter investigates the efficacy of novel anti-aging agents, including exosomes and boron compounds, using the D-galactose-induced accelerated aging model. Both in vitro (skin organoid models) and in vivo (rat models) systems are employed to explore cellular, molecular, and histological changes. This comprehensive analysis provides critical insights into the potential of these agents in reversing age-associated pathologies.

Dietary purslane modulates gut microbiota and fecal metabolites in aging rats

Introduction

Portulaca oleracea L. (purslane) is a highly nutritious and edible wild vegetable beneficial to human health. However, its impacts on the structure of gut microbiota and fecal metabolites in aging individuals remain unclear. This study aims to clarify its potential mechanisms in aging-related gut health.

Methods

Naturally aged rats (18 months) were divided into two groups. One group was fed a maintenance chow, and the other was fed a mixture with 3.5% purslane for 15 weeks. Hematoxylin-eosin staining, gas chromatography-mass spectrometry, and 16S rDNA high-throughput sequencing were employed to explore the effects of purslane on the intestinal health of these rats.

Results

The fecal concentrations of acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, and total short-chain fatty acids (SCFAs) were significantly increased in aging rats fed the purslane supplement. Purslane significantly reduced the relative abundance levels of Firmicutes and Fusobacteria, as well as the ratio of Firmicutes to Bacteroidetes. KEGG pathway analysis annotated 109 differential metabolites, which mainly affected metabolic pathways such as linoleic acid metabolism, arachidonic acid metabolism, primary bile acid biosynthesis, steroid biosynthesis, and steroid hormone biosynthesis. There was a strong correlation between Paracbacteroides, the Prevotella NK3B31_group, the Rikenella_RC9_gut_group, and SCFA levels. Aging rats consuming purslane had a more complete and healthy gut morphology than the control group.

Discussion

These results suggested that the maintenance of intestinal health by purslane in aging rats might be associated with the targeted regulation of gut microbiota and fecal metabolites.

Medial septum deep brain stimulation enhances memory and hippocampal neurogenesis in the D-galactose induced rat model of aging: behavioral and immunohistochemical study

One of the cardinal features of aging is brain aging, which manifests itself in impaired cognitive functions. Experimental data suggest that deep brain stimulation (DBS) can improve memory functions when stimulating specific brain regions. In present study we tested the hypothesis that medial septum (MS) DBS enhances memory function by modulating the hippocampal neurogenesis in the D-galactose (D-gal) induced rat model of aging. Rats were randomly assigned to four experimental groups: (1) control, (2) administration of D-gal, (3) administration of D-gal and electrode implantation and (4) administration of D-gal, electrode implantation and stimulation. Our results showed that MS DBS significantly enhanced the memory functions in an animal model of aging induced by D-gal administration, which impaired long-term spatial memory in the Morris water maze and impaired spatial and object novelty recognition memory in the open field. The immunohistochemical studies showed that in the Dentate Gyrus (DG) of rats with D-gal administration or D-gal combined with electrode implantation, the number of NeuN (neuronal nuclear antigen) or Doublecortin-immunopositive cells decreased (Doublecortin - a biomarker for the post-mitotic phase of cells); MS stimulation increases the number of these cells in the DG to levels comparable to the control group. Thus, MS-DBS restores the level of hippocampal neurogenesis. The present data demonstrate for the first time that chronic DBS of the MS restores memory functions in a D-gal-induced animal model of aging, and that one of the important underlying mechanisms is mediated by enhanced neurogenesis in the hippocampus.

Inflammaging and Immunosenescence in the Post-COVID Era: Small Molecules, Big Challenges

Aging naturally involves a decline in biological functions, often triggering a disequilibrium of physiological processes. A common outcome is the altered response exerted by the immune system to counteract infections, known as immunosenescence, which has been recognized as a primary cause, among others, of the so-called long-COVID syndrome. Moreover, the uncontrolled immunoreaction leads to a state of subacute, chronic inflammatory state known as inflammaging, responsible in turn for the chronicization of concomitant pathologies in a self-sustaining process. Anti-inflammatory and immunosuppressant drugs are the current choice for the therapy of inflammaging in post-COVID complications, with contrasting results. The increasing knowledge of the biochemical pathways of inflammaging led to disclose new small molecules-based therapies directed toward different biological targets involved in inflammation, immunological response, and oxidative stress. Herein, paying particular attention to recent clinical data and preclinical literature, we focus on the role of endocannabinoid system in inflammaging, and the promising therapeutic option represented by the CB2R agonists, the role of novel ligands of the formyl peptide receptor 2 and ultimately the potential of newly discovered monoamine oxidase (MAO) inhibitors with neuroprotective activity in the treatment of immunosenescence.

From Molecular Therapies to Lysosomal Transplantation and Targeted Drug Strategies: Present Applications, Limitations, and Future Prospects of Lysosomal Medications

Lysosomes are essential intracellular organelles involved in plentiful cellular processes such as cell signaling, metabolism, growth, apoptosis, autophagy, protein processing, and maintaining cellular homeostasis. Their dysfunction is linked to various diseases, including lysosomal storage disorders, inflammation, cancer, cardiovascular diseases, neurodegenerative conditions, and aging. This review focuses on current and emerging therapies for lysosomal diseases (LDs), including small medicines, enzyme replacement therapy (ERT), gene therapy, transplantation, and lysosomal drug targeting (LDT). This study was conducted through databases like PubMed, Google Scholar, Science Direct, and other research engines. To treat LDs, medicines target the lysosomal membrane, acidification processes, cathepsins, calcium signaling, mTOR, and autophagy. Moreover, small-molecule therapies using chaperones, macro-therapies like ERT, gene therapy, and gene editing technologies are used as therapy for LDs. Additionally, endosymbiotic therapy, artificial lysosomes, and lysosomal transplantation are promising options for LD management. LDT enhances the therapeutic outcomes in LDs. Extracellular vesicles and mannose-6-phosphate-tagged nanocarriers display promising approaches for improving LDT. This study concluded that lysosomes play a crucial role in the pathophysiology of numerous diseases. Thus, restoring lysosomal function is essential for treating a wide range of conditions. Despite endosymbiotic therapy, artificial lysosomes, lysosomal transplantation, and LDT offering significant potential for LD control, there are ample challenges regarding safety and ethical implications.

What Is the Impact of Obesity-Related Comorbidities on the Risk of Premature Aging in Patients with Severe Obesity?: A Cross-Sectional Study

Background and Objectives: The relationships between aging, chronic diseases, and obesity remain complex and poorly understood. This study aimed to investigate the impact of comorbidities on premature aging in individuals with severe obesity. Materials and Methods: This cross-sectional study included 99 bariatric patients with severe obesity (SG) and 30 healthy volunteers (HC). SG was further divided into subgroups based on comorbidity status. Various markers of biological aging, including interleukin-6 (IL-6), C-reactive protein (CRP), telomere length (TL), attention speed, executive functions, and metabolic age, were evaluated. Results: Both subgroups of patients with obesity presented elevated levels of IL-6 and CRP, shorter TLs, lower outcomes in executive functioning tests, and greater metabolic age than healthy subjects. However, no significant differences were observed between patients with obesity with and without comorbidities. This study highlighted the impact of BMI on increased inflammation and revealed that hypertension and inflammation are associated with cognitive decline. Conclusions: These findings suggest that obesity, regardless of comorbidities, contributes to premature aging. The presence of hypertension was linked to cognitive function decline, emphasizing the multifaceted implications of obesity for the aging process.

Association between weight-adjusted-waist index and serum anti-aging protein α-Klotho in U.S. adults: Evidence from NHANES 2007-2016

BACKGROUND

As unhealthy diets have proliferated, there has been an increasing trend in the prevalence of obesity along with socioeconomic progress. WWI, mainly representing weight-independent central obesity, is a more accurate indicator of obesity than BMI and WC. Klotho is known to be one of the root causes of several age-related illnesses. There has never been any prior evidence associating WWI and serum α-Klotho levels.

METHODS

The current cross-sectional investigation used data from the National Health and Nutrition Examination Survey (NHANES) 2013-2016. The calculation of each participant's WWI involved dividing their waist circumference in centimeters by the square root of their weight in kilograms. Using multivariable linear regression models, the association between serum Klotho concentrations and WWI was analyzed. Smoothed curve fitting was utilized to investigate the nonlinear connection. In addition, interaction tests and other subgroup analyses were carried out.

RESULTS

With an average age of 57.57 ± 10.81 years, 13,172 participants were enrolled in this study, of whom 51.45 % were female. After full adjustment, each unit increase in WWI was significantly associated with a decrease in Klotho by 23.18 ng/ml [β(95%CI) = -23.18 (-31.34, -15.02)]. Moreover, we uncovered that WWI had a stronger negative correlation with Klotho than other obesity markers, such as WC, body mass index (BMI), and a body shape index (ABSI).

CONCLUSIONS

To sum up, weight-adjusted-waist index levels were negatively associated with serum Klotho protein concentration and showed a stronger correlation than other obesity markers. Our findings indicated that WWI may be a predictor of reduced Klotho levels, and that controlling obesity in accordance with WWI may help lower the Klotho levels.

Redox Metabolism and Autonomic Regulation During Aging: Can Heart Rate Variability Be Used to Monitor Healthy Longevity?

The functionality of redox metabolism is frequently named as an important contributor to the processes of aging and anti-aging. Excessive activation of free radical reactions accompanied by the inability of the antioxidant defense (AOD) mechanisms to control the flow of the reactive oxygen species (ROS) leads to the persistence of oxidative stress, hypoxia, impaired mitochondrial energy function and reduced ATP potential. From a long-term perspective, such changes contribute to the development of chronic diseases and facilitate aging. In turn, preconditioning of a biosystem with small doses of stressful stimuli might cause mobilization of the mechanisms of AOD and control an excessive flow of ROS, which supports optimal functioning of the redox reactions. Those mechanisms are of crucial importance for anti-aging and are also known as a eustress or hormetic response. To ensure continuous support of mild pro-oxidant activity in a metabolic system, close monitoring and timely corrections preventing the development of excessive ROS production are required. The paper introduces the potential of heart rate variability (HRV) as a biomarker of functional and metabolic reserves and a tool to measure stress resilience during aging. The practical approaches to interpretation of HRV are provided based on total power, changes in total power in response to an orthostatic test and activities of all spectral components. It is suggested that the complex of those parameters can reflect the depth of oxidative stress and may be used to guide lifestyle interventions and promote active longevity.

Circadian Rhythms and Lung Cancer in the Context of Aging: A Review of Current Evidence

Circadian rhythm is the internal homeostatic physiological clock that regulates the 24-hour sleep/wake cycle. This biological clock helps to adapt to environmental changes such as light, dark, temperature, and behaviors. Aging, on the other hand, is a process of physiological changes that results in a progressive decline in cells, tissues, and other vital systems of the body. Both aging and the circadian clock are highly interlinked phenomena with a bidirectional relationship. The process of aging leads to circadian disruptions while dysfunctional circadian rhythms promote age-related complications. Both processes involve diverse physiological, molecular, and cellular changes such as modifications in the DNA repair mechanisms, mechanisms, ROS generation, apoptosis, and cell proliferation. This review aims to examine the role of aging and circadian rhythms in the context of lung cancer. This will also review the existing literature on the role of circadian disruptions in the process of aging and vice versa. Various molecular pathways and genes such as BMAL1, SIRT1, HLF, and PER1 and their implications in aging, circadian rhythms, and lung cancer will also be discussed.

Aging: Disease or "natural" process? A glimpse from regenerative medicine

We explore aging as a global phenomenon, questioning whether it constitutes a treatable condition or follows a natural course. Acknowledging its multifactorial nature, we delve into the challenges and opportunities inherent in this intricate biological process. The inclusion of old age in the 11th International Classification of Diseases sparks debate, categorizing it as a disease based on mechanistic explanations, blood-based biomarkers, and anti-aging products. Ethical dilemmas arise, emphasizing the difficulty of defining the transition from normal to pathological states during this process. We suggest that aging should be regarded as a treatable condition without necessarily labeling it a 'disease.' While anti-aging research unveils promising interventions like Metformin, Rapamycin, and cellular therapy, achieving biological immortality remains a formidable challenge. The future promises to prolong life and enhance quality by comprehensively understanding aging's implications for human health.

Astragalus Polysaccharide Alleviates Cognitive Decline in D-Galactose-Induced Aging

Astragalus polysaccharide (APS) is a biologically active water-soluble polysaccharide extracted from stems or roots, which has been proven to have antiaging effects. The aim of this study was to investigate the effects of APS on cognitive function in d-galactose (d-gal)-induced aging rats and explore the potential underlying molecular mechanisms. The rats were induced to age by intraperitoneal injection with 400 mg/kg/d d-gal for 8 weeks. Aging of rats was assessed through the Morris water maze test, step-down test, open field test, and grip strength test. Pathological changes in the hippocampal CA3 and CA1 regions were determined by Hematoxylin and eosin and Nissl staining. The superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), and total antioxidant capacity (T-AOC) in the serum were measured. Telomere length, dual oxidase 1 (Duox1), dual oxidase 2 (Duox2), peroxiredoxin 1 (Prdx1), p21, p16, p53, telomerase reverse transcriptase (TERT), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), nicotinamide phosphoribosyl transferase (NAMPT), and sirtuin 1 (SIRT1) were detected via real-time PCR, Western blotting, and immunohistochemical staining. The results indicated that APS ameliorated the general status in d-gal-induced aging rats, mitigated neuronal degeneration in the CA3 and CA1 regions, reduced the oxidative stress levels, modulated senescence-related β-GAL and protein expression, and maintained telomere length. Furthermore, APS significantly reduced p53 expression and increased p-PI3K, p-AKT, NAMPT, SIRT1, and TERT expression. Therefore, d-gal-induced aging and cognitive impairment in rats can be prevented by APS, likely through regulation of the TERT/p53 signaling axis via the PI3K/Akt and NAMPT/SIRT1 signaling pathways.

The Protective Role of Vitamin K in Aging and Age-Related Diseases

Aging is an inevitable aspect of life, but age-related diseases are not an inseparable part of the aging process, and their risk can be reduced through a healthy lifestyle. Vitamin K has a broader impact than just blood clotting, and yet it remains overshadowed by other vitamins and underestimated by both doctors and consumers. Vitamin K (VK) is a multifunctional micronutrient with anti-inflammatory and antioxidant properties, whose deficiency may cause age-related diseases such as cardiovascular diseases, neurodegenerative diseases and osteoporosis. There is a growing body of evidence supporting the role of vitamin K as a protective nutrient in aging and inflammation. This review summarizes the current knowledge regarding the molecular aspects of the protective role of vitamin K in aging and age-related diseases and its clinical implications.

Drug delivery for age-related bone diseases: From therapeutic targets to common and emerging therapeutic strategies

With the accumulation of knowledge on aging, people have gradually realized that among the many factors that cause individual aging, the accumulation of aging cells is an essential cause of organ degeneration and, ultimately, age-related diseases. Most cells present in the bone microenvironment gradually age over time, leading to an imbalance of osteogenesis, osteoclastogenesis, adipogenesis, and chondrogenesis. This imbalance contributes to age-related bone loss and the development of age-related bone diseases, such as osteoporosis. Bone aging can prolong the lifespan and delay the development of age-related diseases. Nanoparticles have controllable and stable physical and chemical properties and can precisely target different tissues and organs. By preparing multiple easily modified and biocompatible nanoparticles as different drug delivery carriers, specifically targeting various diseased tissues for controlled-release and sustained-release administration, the delivery efficiency of drugs can be significantly improved, and the toxicity and side effects of drugs can be substantially reduced, thereby improving the therapeutic effect of age-related bone diseases. In addition, other novel anti-aging strategies (such as stem cell exosomes) also have significant scientific and practical significance in anti-aging research on age-related bone diseases. This article reviews the research progress of various nano-drug-loaded particles and emerging anti-aging methods for treating age-related bone diseases, offering new insights and directions for precise targeted clinical therapies.

Zanthoxylum alkylamides alleviate cell cycle arrest and oxidative stress to retard d-galactose-induced aging

During the aging process, the abilities to maintain homeostasis and resist stress decrease, leading to degenerative changes in tissues and organs. The pathological process of aging is characterized by oxidative stress and cell cycle arrest. Zanthoxylum alkylamides (ZA) can mitigate hepatic oxidative stress. However, whether ZA can delay aging and the underlying mechanisms are unclear. Herein, ZA were shown to inhibit d-galactose-induced aging in a dose-dependent manner. ZA activated CyclinD1 and CyclinE2 to exert anti-cell cycle arrest effects and activated the Nrf2/HO1 pathway to reduce the accumulated intracellular reactive oxygen species (ROS) and improve antioxidant capacity. Moreover, motor coordination and spontaneous exploration were improved in aging mice administered ZA. Overall, ZA alleviated cell cycle arrest and oxidative stress to delay d-galactose-induced aging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01599-9.

Reactive oxygen species in age-related musculoskeletal decline: implications for nutritional intervention

Musculoskeletal disorders and age-related musculoskeletal decline are major contributors to the burden of ill health seen in older subjects. Despite this increased burden, these chronic disorders of old age receive a relatively small proportion of national research funds. Much has been learned about fundamental processes involved in ageing from basic science research and this is leading to identification of key pathways that mediate ageing which may help the search for interventions to reduce age-related musculoskeletal decline. This short review will focus on the role of reactive oxygen species in age-related skeletal muscle decline and on the implications of this work for potential nutritional interventions in sarcopenia. The key physiological role of reactive oxygen species is now known to be in mediating redox signalling in muscle and other tissues and ageing leads to disruption of such pathways. In muscle, this is reflected in an age-related attenuation of specific adaptations and responses to contractile activity that impacts the ability of skeletal muscle from ageing individuals to respond to exercise. These pathways provides potential targets for identification of logical interventions that may help maintain muscle mass and function during ageing.

Prevalence and risk factors for sarcopenia in active community-dwelling older adults according to the EWGSOP2 criteria

The prevalence of sarcopenia depends on the diagnostic criteria and updates used. There are few studies investigating the relationship between the European Working Group on Sarcopenia in Older People (EWGSOP2) criteria and risk factors in active community-dwelling older adults. In this cross-sectional study, a total of 533 community-dwelling active older adults were assessed. 3.75 % were diagnosed with confirmed sarcopenia and 15.86 % with probable sarcopenia. The risk of sarcopenia was found to increase with age, taking more than four tablets a day and having a low level of education. There is a possible association between smoking and living alone. In contrast, active older adults had a lower prevalence of sarcopenia compared to the European and global populations, suggesting a protective effect of physical activity adherence against sarcopenia. Further studies in this population are needed to increase the sample size and to better understand the development and factors associated with sarcopenia.

Aging abolishes circadian rhythms and disrupts temporal organization of antioxidant-prooxidant status, endogenous clock activity and neurotrophin gene expression in the rat temporal cortex

Disruption of circadian rhythms contributes to deficits in cognitive functions during aging. Up to date, the biochemical, molecular and chronobiological bases of such deterioration have not been completely elucidated. Here, we aim: 1) to investigate the endogenous nature of 24 h-rhythms of antioxidant defenses, oxidative stress, clocḱ's, and neurotrophic factors expression, in the rat temporal cortex (TC), and 2) to study the consequences of aging on the circadian organization of those factors. We observed a circadian organization of antioxidant enzymes activity, lipoperoxidation and the clock, BMAL1 and RORa, proteins, in the TC of young rats. Such temporal organization suggests the existence of a two-way communication among clock transcription factors and antioxidant defenses. This might generate the rhythmic and circadian expression of Bdnf and Rc3 genes involved in the TC-depending cognitive function. Noteworthy, such circadian organization disappears in the TC of aged rats. Aging also reduces glutathione peroxidase activity and expression, and it increases lipid peroxidation, throughout a 24 h-period. An increased oxidative stress makes the cellular redox environment change into an oxidative status which alters the endogenous clock activity and disrupts the circadian organization of, at least part, of the molecular basis of the synaptic plasticity in the TC.

Gender differences in weight-adjusted waist index in elderly inhabitants of a geriatric center

INTRODUCTION AND AIM

Weight-adjusted waist index (WWI) represents a novel anthropometric measure for assessing obesity. Bearing in mind that there is insufficient data in the literature regarding gender differences in WWI values, the aim of the current study was to examine gender differences in WWI values among older adults.

The role of interleukin-10 in mitigating endoplasmic reticulum stress in aged mice through exercise

Although unfolded protein response (UPR) is essential for cellular protection, its prolonged activation may induce apoptosis, compromising cellular longevity. The aging process increases the endoplasmic reticulum (ER) stress in skeletal muscle. However, whether combined exercise can prevent age-induced ER stress in skeletal muscle remains unknown. Evidence suggests that ER stress may increase inflammation by counteracting the positive effects of interleukin-10 (IL-10), whereas its administration in cells inhibits ER stress and apoptosis. This study verified the effects of aging and combined exercise on physical performance, ER stress markers, and inflammation in the quadriceps of mice. Moreover, we verified the effects of IL-10 on ER stress markers. C57BL/6 mice were distributed into young (Y, 6 mo old), old sedentary (OS, sedentary, 24 mo old), and old trained group (OT, submitted to short-term combined exercise, 24 mo old). To clarify the role of IL-10 in UPR pathways, knockout mice lacking IL-10 were used. The OS mice presented worse physical performance and higher ER stress-related proteins, such as C/EBP homologous protein (CHOP) and phospho-eukaryotic translation initiation factor 2 alpha (p-eIF2α/eIF2α). The exercise protocol increased muscle strength and IL-10 protein levels in OT while inducing the downregulation of CHOP protein levels compared with OS. Furthermore, mice lacking IL-10 increased BiP, CHOP, and p-eIF2α/eIF2α protein levels, indicating this cytokine can regulate the ER stress response in skeletal muscle. Bioinformatics analysis showed that endurance and resistance training downregulated DNA damage inducible transcript 3 (DDIT3) and XBP1 gene expression in the vastus lateralis of older people, reinforcing our findings. Thus, combined exercise is a potential therapeutic intervention for promoting adjustments in ER stress markers in aged skeletal muscle.NEW & NOTEWORTHY Aging elevates endoplasmic reticulum (ER) stress in skeletal muscle, potentially heightening inflammation by opposing interleukin-10 (IL-10) effects. This study found that short-term combined exercise boosted strength and IL-10 protein levels while reducing CHOP protein levels in older mice. In addition, IL-10-deficient mice exhibited increased ER stress markers, highlighting IL-10's role in regulating ER stress in skeletal muscle. Consequently, combined exercise emerges as a therapeutic intervention to elevate IL-10 and adjust ER stress markers in aging.

The Interplay between Mechanoregulation and ROS in Heart Physiology, Disease, and Regeneration

Cardiovascular diseases are currently the most common cause of death in developed countries. Due to lifestyle and environmental factors, this problem is only expected to increase in the future. Reactive oxygen species (ROS) are a key player in the onset of cardiovascular diseases but also have important functions in healthy cardiac tissue. Here, the interplay between ROS generation and cardiac mechanical forces is shown, and the state of the art and a perspective on future directions are discussed. To this end, an overview of what is currently known regarding ROS and mechanosignaling at a subcellular level is first given. There the role of ROS in mechanosignaling as well as the interplay between both factors in specific organelles is emphasized. The consequences at a larger scale across the population of heart cells are then discussed. Subsequently, the roles of ROS in embryogenesis, pathogenesis, and aging are further discussed, exemplifying some aspects of mechanoregulation. Finally, different models that are currently in use are discussed to study the topics above.

Exploring the Geroprotective Potential of Nutraceuticals

Aging is the result of the accumulation of a wide variety of molecular and cellular damages over time, meaning that "the more damage we accumulate, the higher the possibility to develop age-related diseases". Therefore, to reduce the incidence of such diseases and improve human health, it becomes important to find ways to combat such damage. In this sense, geroprotectors have been suggested as molecules that could slow down or prevent age-related diseases. On the other hand, nutraceuticals are another set of compounds that align with the need to prevent diseases and promote health since they are biologically active molecules (occurring naturally in food) that, apart from having a nutritional role, have preventive properties, such as antioxidant, anti-inflammatory and antitumoral, just to mention a few. Therefore, in the present review using the specialized databases Scopus and PubMed we collected information from articles published from 2010 to 2023 in order to describe the role of nutraceuticals during the aging process and, given their role in targeting the hallmarks of aging, we suggest that they are potential geroprotectors that could be consumed as part of our regular diet or administered additionally as nutritional supplements.

The association of platelet count, high-density lipoprotein cholesterol, and platelet/high-density lipoprotein cholesterol ratio with serum soluble Klotho

BACKGROUND AND OBJECTIVE

Klotho is a protein that is closely related to human aging. Soluble Klotho (S-Klotho) is a circulating protein, and its level decreases in response to systemic inflammation. The relationship between the platelet/high-density lipoprotein cholesterol ratio (PHR), an emerging inflammatory index, and S-Klotho concentrations is still unclear. In addition, the mean platelet volume has been confirmed to have a significant negative association with S-Klotho concentrations, but the relationship between the platelet count (PC) and S-Klotho concentrations has not yet been reported.

METHODS

Data from individuals who participated in the National Health and Nutrition Examination Survey (NHANES) during the five cycles from 2007 to 2016 were retrieved for analysis. Linear regression, two-piecewise linear regression, and restricted cubic spline (RCS) methods were used to analyze the associations of the PHR index and its components with S-Klotho concentrations. In addition, subgroup analysis and effect modification tests were conducted.

RESULTS

A total of 11,123 participants (5463 men (48.17%)), with an average age of 56.2 years, were included. After full adjustment, the S-Klotho levels of participants in the highest quartile group of PHR (β: -51.19, 95% CI: -75.41 to -26.97, P < 0.001) and the highest quartile group of PC (β: -72.34, 95% CI: -93.32 to -51.37, P < 0.0001) were significantly lower than those in their respective lowest quartile groups, and a significant downward trend was presented among the four groups (P for trend < 0.05, respectively). However, high-density lipoprotein cholesterol (HDL-C) concentrations were not significantly associated with S-Klotho concentrations. RCS revealed that the PHR and PC were nonlinearly associated with S-Klotho concentrations; two-piecewise linear regression revealed that the inflection points were 175.269 and 152, respectively, and that these associations slightly weakened after the inflection point. According to the subgroup analysis, liver disease status enhanced the association between the PC and S-Klotho concentrations.

CONCLUSIONS

Both the PHR and PC were significantly negatively associated with S-Klotho concentrations, and these associations were nonlinear. There was no significant association between HDL-C and S-Klotho concentrations. Liver disease status enhances the negative association between the PC and S-Klotho concentrations, and the specific mechanism deserves further exploration.

Immunoglobulin G glycosylation and its alterations in aging-related diseases

Immunoglobulin G (IgG) is an important serum glycoprotein and a major component of antibodies. Glycans on IgG affect the binding of IgG to the Fc receptor or complement C1q, which in turn affects the biological activity and biological function of IgG. Altered glycosylation patterns on IgG emerge as important biomarkers in the aging process and age-related diseases. Key aging-related alterations observed in IgG glycosylation include reductions in galactosylation and sialylation, alongside increases in agalactosylation, and bisecting GlcNAc. Understanding the role of IgG glycosylation in aging-related diseases offers insights into disease mechanisms and provides opportunities for the development of diagnostic and therapeutic strategies. This review summarizes five aspects of IgG: an overview of IgG, IgG glycosylation, IgG glycosylation with inflammation mediation, IgG glycan changes with normal aging, as well as the relevance of IgG glycan changes to aging-related diseases. This review provides a reference for further investigation of the regulatory mechanisms of IgG glycosylation in aging-related diseases, as well as for evaluating the potential of IgG glycosylation changes as markers of aging and aging-related diseases.

Cumulative Effect of Psychosis and Aging on Cognitive Function in Patients Diagnosed With Schizophrenia Spectrum Disorders: A Cognitive Domain Approach

BACKGROUND

Schizophrenia spectrum disorders are characterized by cognitive decline, which is evident even in the prodromal phase. Aging is a complex gradual procedure that affects, among other organs, the central nervous system, resulting in age-related cognitive decline.

OBJECTIVE

The objective of this study is to assess the cognitive function of patients diagnosed with psychotic disorders, in comparison with healthy controls, along the age spectrum.

METHODS

Sixty patients diagnosed with schizophrenia spectrum disorders in remission, 20-59 years old, and 60 healthy controls, matched by age and educational level, from the region of Thessaly in Central Greece, were evaluated, with respect to their cognitive performance, using the Greek version of the Montreal Cognitive Assessment (MoCA). Correlations between age and MoCA total and cognitive domains' scores, as well as statistical analysis of variance (ANOVA) and t-test among age groups, were performed using Statistical Product and Service Solutions (SPSS, version 23; IBM SPSS Statistics for Windows, Armonk, NY).

RESULTS

The MoCA score was negatively correlated with age, both in the patients' group (p<0.001) and in the control group (p=0.001). A significant statistical difference in mean MoCA scores between patients and healthy controls was observed, not only in the total sample (p<0.001) but also in all age groups (20-29: p=0.006, 40-49: p=0.024, 50-59: p<0.001), except for age group 30-39 (30-39: p=0.356). Statistically significant differences were also found between patients and healthy controls in the total sample, regarding specific cognitive domains, in the visuospatial and executive function domain (p=0.01), attention domain (p<0.001), language domain (p<0.001), and orientation domain (p<0.005). Interestingly, different deterioration patterns in cognitive domains were observed in each age group. Specifically, in the age group 20-29, statistically significant differences were found between patients and healthy controls in the language domain (p<0.014) and orientation domain (p<0.041). No difference was found in the age group 30-39, while statistically significant differences were found between patients and healthy controls in the age group 40-49 in the attention domain (p<0.001) and language domain (p<0.001). Finally, in the age group 50-59, such differences were found in the visuospatial and executive function domain (p=0.041), attention domain (p=0.006), and language domain (p=0.001). Statistically significant cognitive decline occurs in a shorter period in the patients' group, suggesting an accelerated cognitive decline in psychotic patients after middle age.

CONCLUSIONS

Age-related cognitive decline in psychotic patients occurs at an accelerated rate in relation to the control sample, with age-specific cognitive domain decline patterns, due to the cumulative effect of aging and psychosis on cognition. Further, larger, multicenter research should focus on establishing these results and designing relevant procognitive interventions.

Linear-inverse associations of serum Klotho protein with prevalence of frailty among adults in the United States

AIMS

To investigate the potential linear relationship between serum concentrations of klotho and frailty.

METHODS

A retrospective analysis was conducted on the data of 9,597 middle-aged and older adults (aged 40-79 years) from the five cycles of the National Health and Nutrition Examination Survey (NHANES). Frailty was assessed using the Frailty Index, calculated as a percentage of accumulated deficits across 53 health items. Restricted cubic spline curves, subgroup analyses and logistic regression models were employed to evaluate the specific linear trend connection between circulating klotho protein concentration and frailty.

RESULTS

When taking Klotho into account as a continuous component in Models 1 and 2, there was a substantial association between the increasing Klotho level and the reduced risk of frailty. Model 3 revealed a strong negative correlation between the Klotho and Frailty, suggesting that high levels of Klotho protein decreases the frailty prevalence [Odd ratio (OR): 0.25; 95% confidence interval (CI): 0.15-0.43]. Furthermore, according to the quartile analyses, after fully adjusting for the covariates, it was observed that, comparing to the lowest quartile of Klotho, the highest quartile of Klotho demonstrated lowest risk of frailty (OR 0.69; 95% CI 0.58-0.81, Ptrend < 0.001). The restricted cubic spline curves showed a linear relationship and an inverse association between frailty and the Klotho levels (Plinearity < 0.001; Pnon-linearity = 0.736).

CONCLUSION

Klotho is inversely and linearly associated with physical frailty in the general population (aged 40-79 years), specifically in the population with an age < 65 and body mass index (BMI) ≥ 25 kg/m2. More necessary prospective studies should be done to further investigate the mechanisms underlying frailty and aging and to elucidate individual frailty causes.

More than a number: Incorporating the aged phenotype to improve in vitro and in vivo modeling of neurodegenerative disease

Age is the number one risk factor for developing a neurodegenerative disease (ND), such as Alzheimer's disease (AD) or Parkinson's disease (PD). With our rapidly ageing world population, there will be an increased burden of ND and need for disease-modifying treatments. Currently, however, translation of research from bench to bedside in NDs is poor. This may be due, at least in part, to the failure to account for the potential effect of ageing in preclinical modelling of NDs. While ageing can impact upon physiological response in multiple ways, only a limited number of preclinical studies of ND have incorporated ageing as a factor of interest. Here, we evaluate the aged phenotype and highlight the critical, but unmet, need to incorporate aspects of this phenotype into both the in vitro and in vivo models used in ND research. Given technological advances in the field over the past several years, we discuss how these could be harnessed to create novel models of ND that more readily incorporate aspects of the aged phenotype. This includes a recently described in vitro panel of ageing markers, which could help lead to more standardised models and improve reproducibility across studies. Importantly, we cannot assume that young cells or animals yield the same responses as seen in the context of ageing; thus, an improved understanding of the biology of ageing, and how to appropriately incorporate this into the modelling of ND, will ensure the best chance for successful translation of new therapies to the aged patient.

L-shaped association of systemic immune-inflammation index (SII) with serum soluble α-Klotho in the prospective cohort study from the NHANES database

The systemic immune-inflammation index (SII), an integrated and ground-breaking inflammatory measure, has been widely used in various fields. We aimed to assess the association between the systemic immune-inflammation index (SII) and α-Klotho (a new anti-aging biomarker). In this cross-sectional investigation, people with complete information on SII and α-Klotho from the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016 were the study's subject population. SII was calculated by platelet count × neutrophil count/lymphocyte count. The association between SII and α-Klotho was investigated using multivariable linear regression and a generalized additive model. In order to explore the non-linear connection, we employed smoothed curve fitting. Subgroup analysis were also performed. A total of 13,701 participants with an average age of 57.73 ± 10.86 years were enrolled, of whom 51.53% were female. After fully adjustment, SII was negatively associated with serum soluble α-Klotho [β(95% CI) =  - 0.07 (- 0.08, - 0.05)]. Furthermore, we found L-shaped association between SII and klotho protein level, with the inflection point at 255 pg/ml. Subgroup analysis and interaction test revealed that there was no discernible dependence on gender, age, race, smoking, alcohol, diabetes and hypertension (all p for interaction > 0.05). SII level was negatively associated with serum klotho protein concentration in American adults. To verify our findings, more large-scale prospective investigations are still required.

MicroRNA-7 deficiency ameliorates d-galactose-induced aging in mice by regulating senescence of Kupffer cells

Aging is intricately linked to immune system dysfunction. Recent studies have highlighted the biological function of microRNA-7 (miR-7) as a novel regulator of immune cell function and related diseases. However, the potential role of miR-7 in aging remains unexplored. Here, we investigated the contribution of miR-7 to d-gal-induced aging in mice, focusing on its regulation of senescent Kupffer cells. Our findings revealed that miR-7 deficiency significantly ameliorated the aging process, characterized by enhanced CD4+ T-cell activation. However, the adoptive transfer of miR-7-deficient CD4+T cells failed to improve the age-related phenotype. Further analysis showed that miR-7 deficiency significantly reduced IL-1β production in liver tissue, and inhibiting IL-1β in vivo slowed down the aging process in mice. Notably, IL-1β is mainly produced by senescent Kupffer cells in the liver tissue of aging mice, and miR-7 expression was significantly up-regulated in these cells. Mechanistically, KLF4, a target of miR-7, was down-regulated in senescent Kupffer cells in aging mouse model. Furthermore, miR-7 deficiency also modulated the NF-κB activation and IL-1β production in senescent Kupffer cells through KLF4. In conclusion, our findings unveil the role of miR-7 in d-gal-induced aging in mice, highlighting its regulation of KLF4/NF-κB/IL-1β pathways in senescent Kupffer cells. This research may enhance our understanding of miRNA-based aging immune cells and offer new avenues for new intervention strategies in aging process.

Eliminating senescent cells by white adipose tissue-targeted senotherapy alleviates age-related hepatic steatosis through decreasing lipolysis

Cellular senescence is an important risk factor in the development of hepatic steatosis. Senolytics present therapeutic effects on age-related hepatic steatosis without eliminating senescent hepatocytes directly. Therefore, it highlights the need to find senolytics' therapeutic targets. Dysfunction of adipose tissue underlies the critical pathogenesis of lipotoxicity in the liver. However, the correlation between adipose tissue and hepatic steatosis during aging and its underlying molecular mechanism remains poorly understood. We explored the correlation between white adipose tissue (WAT) and the liver during aging and evaluated the effect of lipolysis of aged WAT on hepatic steatosis and hepatocyte senescence. We screened out the ideal senolytics for WAT and developed a WAT-targeted delivery system for senotherapy. We assessed senescence and lipolysis of WAT and hepatic lipid accumulation after treatment. The results displayed that aging accelerated cellular senescence and facilitated lipolysis of WAT. Free fatty acids (FFAs) generated by WAT during aging enhanced hepatic steatosis and induced hepatocyte senescence. The combined usage of dasatinib and quercetin was screened out as the ideal senolytics to eliminate senescent cells in WAT. To minimize non-specific distribution and enhance the effectiveness of senolytics, liposomes decorated with WAT affinity peptide P3 were constructed for senotherapy in vivo. In vivo study, WAT-targeted treatment eliminated senescent cells in WAT and reduced lipolysis, resulting in the alleviation of hepatic lipid accumulation and hepatocyte senescence when compared to non-targeted treatment, providing a novel tissue-targeted, effective and safe senotherapy for age-related hepatic steatosis.

The association between testosterone and serum soluble klotho in the females: evidence from the NHANES database

Objective

This research aimed to elucidate the relationship between testosterone levels and serum soluble klotho (S-klotho) concentrations in females aged 40-79 years using the National Health and Nutrition Examination Survey (NHANES) dataset.

Design

Associations between testosterone and S-klotho were assessed through multivariable linear regression methodologies, spanning nonadjusted, minimally adjusted, and fully adjusted models.

Settings

The investigation was conducted as a cross-sectional analysis utilizing the NHANES database.

Participants

From 20,146 NHANES participants between 2013 and 2016, 2,444 females met the stipulated inclusion and exclusion criteria.

Results

Free androgen index (FAI) showcased a negative correlation with S-klotho levels across all regression models (nonadjusted: β -7.08, 95% CI -13.39- -0.76; minimally adjusted: β -9.73, 95% CI -16.6- -2.84; fully adjusted: β -7.63, 95% CI -14.75-0.51). Conversely, total testosterone did not exhibit significant associations with S-klotho across the models. In the nonadjusted model, estradiol was positively associated with S-klotho concentrations (β 0.14, 95% CI 0.05-0.23), but this significance was not retained in subsequent regression models.

Conclusion

Findings suggest that in U.S. females aged 40-79 years, FAI negatively correlates with S-klotho concentrations, while there is the lack of significant associations for total testosterone and estradiol.

Bifidobacterium pseudocatenulatum NCU-08 ameliorated senescence via modulation of the AMPK/Sirt1 signaling pathway and gut microbiota in mice

Aging is a degenerative disease in which organisms and neurological functions decline. Emerging research has underscored the vital role of the gut microbiota in age-related processes. However, the identification of aging-associated core microbiota remains limited. In this investigation, we isolated a strain of B. pseudocatenulatum NCU-08 from the feces of centenarians and assessed its impact on aging using a mouse model induced by D-gal. Our study revealed the exceptional probiotic attributes of B. pseudocatenulatum NCU-08. Administration of B. pseudocatenulatum NCU-08 significantly ameliorated age-related memory impairment, motor dysfunction, and anxiety-like behaviors in aging mice (p < 0.01). Moreover, tissue staining analysis demonstrated that B. pseudocatenulatum NCU-08 reduced the intensity of SA-β-gal-positive in the hippocampus of aging mice. It also reversed pathological damage and structural abnormalities in brain and intestinal tissue. B. pseudocatenulatum NCU-08 inhibited neuroinflammation induced by TLR4/NF-κB (p < 0.01) and preserved the blood-brain barrier integrity by activating the AMPK/Sirt1 pathway (p < 0.05). Furthermore, it mitigated neuronal apoptosis and oxidative stress by upregulating the PI3K/AKT signaling pathway (p < 0.01) and enhancing the activities of antioxidant enzymes, including GSH-Px (p < 0.01), SOD (p < 0.01), and CAT (p < 0.01). Besides, analysis of 16S rRNA sequencing data demonstrated that treatment with B. pseudocatenulatum NCU-08 restored intestinal microbiota homeostasis after senescence. It enhanced the abundance of beneficial bacteria while suppressing the growth of pathogenic microorganisms. In summary, our study unveiled that this novel strain of B. pseudocatenulatum NCU-08 exerts anti-aging effects through regulating the AMPK/Sirt1 pathway and intestinal microbiota. It holds promise as a functional food for promoting anti-aging effects and offers a novel approach to address aging and associated metabolic disorders.

Testosterone does not mediate the correlation between dietary inflammation and serum klotho levels among males: insights from NHANES database

Introduction

Serum Klotho (S-Klotho) is a transmembrane protein holds pivotal roles in anti-aging. The Dietary Inflammation Index (DII), a meticulously dietary tool, quantifies the inflammatory potential of an individual's diet. The existing research strongly suggests that a low DII diet plays a significant role in delaying aging and reducing aging-related symptoms in males. Testosterone could potentially act as a mediating intermediary between DII and S-Klotho. However, this aspect remains unexplored. This study aims to investigate the potential causal link of testosterone between DII and S-Klotho in males.

Methods

We utilized data from National Health and Nutrition Examination Survey (NHANES) which focused on male participants from 2013-2016. Mediation analyses were used to investigate the effects of testosterone (TT), free testosterone (FT), and free androgen index (FAI) on the DII-S-Klotho relationship, using three modes adjusting for covariates.

Results

Mediation analysis unveiled a significant inverse correlation between DII and S-Klotho levels (model 1: c = -14.78, p = 0.046). The interaction between DII and S-Klotho was modulated by TT in model 1 (ab = -1.36; 95% CI: -5.59, -0.55; p = 0.008), but lost significance after adjustments (model 2: ab = -0.39; 95% CI: -4.15, 1.66; p = 0.378; model 3: ab = -0.59; 95% CI: -4.08, 2.15; p = 0.442). For FT, the mediating impact was not statistically significant (model 1: ab = 0.43; 95% CI: -0.51, 5.44; p = 0.188; model 2: ab = 0.72; 95% CI: -0.26, 5.91; p = 0.136; model 3: ab = 0.84; 95% CI: -0.02, 8.06; p = 0.056). Conversely, FAI consistently influenced the DII-S-Klotho relationship (model 1: ab = 2.39; 95% CI: 0.69, 9.42; p = 0.002), maintaining significance after adjustments (model 2: ab = 3.2; 95% CI: 0.98, 11.72; p = 0.004; model 3: ab = 3.15; 95% CI: 0.89, 14.51; p = 0.026).

Discussion

This study observed no mediating influence of TT or FT on the correlation between DII and S-Klotho after covariate control. Remarkably, FAI continued to significantly mediate the DII-S-Klotho connection even following covariate adjustment, although its significance in males warrants careful consideration.

Opening avenues for treatment of neurodegenerative disease using post-biotics: Breakthroughs and bottlenecks in clinical translation

Recent studies have indicated the significant involvement of the gut microbiome in both human physiology and pathology. Additionally, therapeutic interventions based on microbiome approaches have been employed to enhance overall health and address various diseases including aging and neurodegenerative disease (ND). Researchers have explored potential links between these areas, investigating the potential pathogenic or therapeutic effects of intestinal microbiota in diseases. This article provides a summary of established interactions between the gut microbiome and ND. Post-biotic is believed to mediate its neuroprotection by elevating the level of dopamine and reducing the level of α-synuclein in substantia nigra, protecting the loss of dopaminergic neurons, reducing the aggregation of NFT, reducing the deposition of amyloid β peptide plagues and ameliorating motor deficits. Moreover, mediates its neuroprotective activity by inhibiting the inflammatory response (decreasing the expression of TNFα, iNOS expression, free radical formation, overexpression of HIF-1α), apoptosis (i.e. active caspase-3, TNF-α, maintains the level of Bax/Bcl-2 ratio) and promoting BDNF secretion. It is also reported to have good antioxidant activity. This review offers an overview of the latest findings from both preclinical and clinical trials concerning the use of post-biotics in ND.

Single-cell immune profiling of mouse liver aging reveals Cxcl2+ macrophages recruit neutrophils to aggravate liver injury

BACKGROUND AND AIMS

Immune cells play a crucial role in liver aging. However, the impact of dynamic changes in the local immune microenvironment on age-related liver injury remains poorly understood. We aimed to characterize intrahepatic immune cells at different ages to investigate key mechanisms associated with liver aging.

APPROACH AND RESULTS

We carried out single-cell RNA sequencing on mouse liver tissues at 4 different ages, namely, the newborn, suckling, young, and aged stages. The transcriptomic landscape, cellular classification, and intercellular communication were analyzed. We confirmed the findings by multiplex immunofluorescence staining, flow cytometry, in vitro functional experiments, and chimeric animal models. Nine subsets of 89,542 immune cells with unique properties were identified, of which Cxcl2+ macrophages within the monocyte/macrophage subset were preferentially enriched in the aged liver. Cxcl2+ macrophages presented a senescence-associated secretory phenotype and recruited neutrophils to the aged liver through the CXCL2-CXCR2 axis. Through the secretion of IL-1β and TNF-α, Cxcl2+ macrophages stimulated neutrophil extracellular traps formation. Targeting the CXCL2-CXCR2 axis limited the neutrophils migration toward the liver and attenuated age-related liver injury. Moreover, the relationship between Cxcl2+ macrophages and neutrophils in age-related liver injury was further validated by human liver transplantation samples.

CONCLUSIONS

This in-depth study illustrates that the mechanism of Cxcl2+ macrophage-driven neutrophil activation involves the CXCL2-CXCR2 axis and provides a potential therapeutic strategy for age-related liver injury.

The effect of intermittent fasting on preventing obesity-related early aging from a molecular and cellular perspective

Obesity is a global health concern owing to its association with numerous degenerative diseases and the fact that it may lead to early aging. Various markers of aging, including telomere attrition, epigenetic alterations, altered protein homeostasis, mitochondrial dysfunction, cellular senescence, stem cell disorders, and intercellular communication, are influenced by obesity. Consequently, there is a critical need for safe and effective approaches to prevent obesity and mitigate the onset of premature aging. In recent years, intermittent fasting (IF), a dietary strategy that alternates between periods of fasting and feeding, has emerged as a promising dietary strategy that holds potential in counteracting the aging process associated with obesity. This article explores the molecular and cellular mechanisms through which IF affects obesity-related early aging. IF regulates various physiological processes and organ systems, including the liver, brain, muscles, intestines, blood, adipose tissues, endocrine system, and cardiovascular system. Moreover, IF modulates key signaling pathways such as AMP-activated protein kinase (AMPK), sirtuins, phosphatidylinositol 3-kinase (PI3K)/Akt, mammalian target of rapamycin (mTOR), and fork head box O (FOXO). By targeting these pathways, IF has the potential to attenuate aging phenotypes associated with obesity-related early aging. Overall, IF offers promising avenues for promoting healthier lifestyles and mitigating the premature aging process in individuals affected by obesity.

Replicative aging in yeast involves dynamic intron retention patterns associated with mRNA processing/export and protein ubiquitination

Saccharomyces cerevisiae (baker's yeast) has yielded relevant insights into some of the basic mechanisms of organismal aging. Among these are genomic instability, oxidative stress, caloric restriction and mitochondrial dysfunction. Several genes are known to have an impact on the aging process, with corresponding mutants exhibiting short- or long-lived phenotypes. Research dedicated to unraveling the underlying cellular mechanisms can support the identification of conserved mechanisms of aging in other species. One of the hitherto less studied fields in yeast aging is how the organism regulates its gene expression at the transcriptional level. To our knowledge, we present the first investigation into alternative splicing, particularly intron retention, during replicative aging of S. cerevisiae. This was achieved by utilizing the IRFinder algorithm on a previously published RNA-seq data set by Janssens et al. (2015). In the present work, 44 differentially retained introns in 43 genes were identified during replicative aging. We found that genes with altered intron retention do not display significant changes in overall transcript levels. It was possible to functionally assign distinct groups of these genes to the cellular processes of mRNA processing and export (e.g., YRA1) in early and middle-aged yeast, and protein ubiquitination (e.g., UBC5) in older cells. In summary, our work uncovers a previously unexplored layer of the transcriptional program of yeast aging and, more generally, expands the knowledge on the occurrence of alternative splicing in baker's yeast.

Tricarboxylic Acid Cycle Intermediates and Individual Ageing

Anti-ageing biology and medicine programmes are a focus of genetics, molecular biology, immunology, endocrinology, nutrition, and therapy. This paper discusses metabolic therapies aimed at prolonging longevity and/or health. Individual components of these effects are postulated to be related to the energy supply by tricarboxylic acid (TCA) cycle intermediates and free radical production processes. This article presents several theories of ageing and clinical descriptions of the top markers of ageing, which define ageing in different categories; additionally, their interactions with age-related changes and diseases related to α-ketoglutarate (AKG) and succinate SC formation and metabolism in pathological states are explained. This review describes convincingly the differences in the mitochondrial characteristics of energy metabolism in animals, with different levels (high and low) of physiological reactivity of functional systems related to the state of different regulatory systems providing oxygen-dependent processes. Much attention is given to the crucial role of AKG and SC in the energy metabolism in cells related to amino acid synthesis, epigenetic regulation, cell stemness, and differentiation, as well as metabolism associated with the development of pathological conditions and, in particular, cancer cells. Another goal was to address the issue of ageing in terms of individual characteristics related to physiological reactivity. This review also demonstrated the role of the Krebs cycle as a key component of cellular energy and ageing, which is closely associated with the development of various age-related pathologies, such as cancer, type 2 diabetes, and cardiovascular or neurodegenerative diseases where the mTOR pathway plays a key role. This article provides postulates of postischaemic phenomena in an ageing organism and demonstrates the dependence of accelerated ageing and age-related pathology on the levels of AKG and SC in studies on different species (roundworm Caenorhabditis elegans, Drosophila, mice, and humans used as models). The findings suggest that this approach may also be useful to show that Krebs cycle metabolites may be involved in age-related abnormalities of the mitochondrial metabolism and may thus induce epigenetic reprogramming that contributes to the senile phenotype and degenerative diseases. The metabolism of these compounds is particularly important when considering ageing mechanisms connected with different levels of initial physiological reactivity and able to initiate individual programmed ageing, depending on the intensity of oxygen consumption, metabolic peculiarities, and behavioural reactions.

Changes in Cells Associated with Insulin Resistance

Insulin is a polypeptide hormone synthesized and secreted by pancreatic β-cells. It plays an important role as a metabolic hormone. Insulin influences the metabolism of glucose, regulating plasma glucose levels and stimulating glucose storage in organs such as the liver, muscles and adipose tissue. It is involved in fat metabolism, increasing the storage of triglycerides and decreasing lipolysis. Ketone body metabolism also depends on insulin action, as insulin reduces ketone body concentrations and influences protein metabolism. It increases nitrogen retention, facilitates the transport of amino acids into cells and increases the synthesis of proteins. Insulin also inhibits protein breakdown and is involved in cellular growth and proliferation. On the other hand, defects in the intracellular signaling pathways of insulin may cause several disturbances in human metabolism, resulting in several chronic diseases. Insulin resistance, also known as impaired insulin sensitivity, is due to the decreased reaction of insulin signaling for glucose levels, seen when glucose use in response to an adequate concentration of insulin is impaired. Insulin resistance may cause, for example, increased plasma insulin levels. That state, called hyperinsulinemia, impairs metabolic processes and is observed in patients with type 2 diabetes mellitus and obesity. Hyperinsulinemia may increase the risk of initiation, progression and metastasis of several cancers and may cause poor cancer outcomes. Insulin resistance is a health problem worldwide; therefore, mechanisms of insulin resistance, causes and types of insulin resistance and strategies against insulin resistance are described in this review. Attention is also paid to factors that are associated with the development of insulin resistance, the main and characteristic symptoms of particular syndromes, plus other aspects of severe insulin resistance. This review mainly focuses on the description and analysis of changes in cells due to insulin resistance.

Antioxidants in Photoaging: From Molecular Insights to Clinical Applications

Photoaging (PA) is considered a silent disease affecting millions of people globally and is defined as skin damage due to prolonged exposure to ultraviolet radiation (UVR) from the sun. Physiologically, the skin is in a state of renewal and synthesis of components of the extracellular matrix (ECM). However, exposure to UVR affects the production of the ECM, and the functioning and response of skin cells to UVR begins to change, thus expressing clinical and phenotypic characteristics of PA. The primary mechanisms involved in PA are direct damage to the DNA of skin cells, increases in oxidative stress, the activation of cell signaling pathways responsible for the loss of skin integrity, and cytotoxicity. The medical and scientific community has been researching new therapeutic tools that counteract PA, considering that the damage caused by UVR exceeds the antioxidant defense mechanisms of the skin. Thus, in recent years, certain nutraceuticals and phytochemicals have been found to exhibit potential antioxidant and photoprotective effects. Therefore, the main objective of this review is to elucidate the molecular bases of PA and the latest pharmaceutical industry findings on antioxidant treatment against the progression of PA.

Considering Caenorhabditis elegans Aging on a Temporal and Tissue Scale: The Case of Insulin/IGF-1 Signaling

The aging process is inherently complex, involving multiple mechanisms that interact at different biological scales. The nematode Caenorhabditis elegans is a simple model organism that has played a pivotal role in aging research following the discovery of mutations extending lifespan. Longevity pathways identified in C. elegans were subsequently found to be conserved and regulate lifespan in multiple species. These pathways intersect with fundamental hallmarks of aging that include nutrient sensing, epigenetic alterations, proteostasis loss, and mitochondrial dysfunction. Here we summarize recent data obtained in C. elegans highlighting the importance of studying aging at both the tissue and temporal scale. We then focus on the neuromuscular system to illustrate the kinetics of changes that take place with age. We describe recently developed tools that enabled the dissection of the contribution of the insulin/IGF-1 receptor ortholog DAF-2 to the regulation of worm mobility in specific tissues and at different ages. We also discuss guidelines and potential pitfalls in the use of these new tools. We further highlight the opportunities that they present, especially when combined with recent transcriptomic data, to address and resolve the inherent complexity of aging. Understanding how different aging processes interact within and between tissues at different life stages could ultimately suggest potential intervention points for age-related diseases.

Age-related bone diseases: Role of inflammaging

Bone aging is characterized by an imbalance in the physiological and pathological processes of osteogenesis, osteoclastogenesis, adipogenesis, and chondrogenesis, resulting in exacerbated bone loss and the development of age-related bone diseases, including osteoporosis, osteoarthritis, rheumatoid arthritis, and periodontitis. Inflammaging, a novel concept in the field of aging research, pertains to the persistent and gradual escalation of pro-inflammatory reactions during the aging process. This phenomenon is distinguished by its low intensity, systemic nature, absence of symptoms, and potential for management. The mechanisms by which inflammaging contribute to age-related chronic diseases, particularly in the context of age-related bone diseases, remain unclear. The precise manner in which systemic inflammation induces bone aging and consequently contributes to the development of age-related bone diseases has yet to be fully elucidated. This article primarily examines the mechanisms underlying inflammaging and its association with age-related bone diseases, to elucidate the potential mechanisms of inflammaging in age-related bone diseases and offer insights for developing preventive and therapeutic strategies for such conditions.

How age and health status impact attitudes towards aging and technologies in care: a quantitative analysis

BACKGROUND

Increasing proportions of geriatric patients pose tremendous challenges for our society. Developments in assistive technologies have the potential to support older and frail people in aging and care. To reach a sustainable adoption of these technologies, the perceptions and wishes of future users must be understood. In particular, the relationships between individual health-related factors, and the perceptions of aging and using assistive technologies in severe health situations must be empirically examined.

METHODS

Addressing this research gap, our quantitative study (N = 570) investigates the impact of diverse future users' age and health status on their a) perceptions of aging, b) perceptions and acceptance of using assistive technologies in aging and care, as well as c) end-of-life decisions regarding technology usage. For this, four groups were segmented for the comparison of younger (< 50 years) healthy, younger chronically ill, older (50 + years) healthy, and older chronically ill participants.

RESULTS

The results revealed that health status is more decisive for age-related perceptions compared to age. The technology-related perceptions were slightly impacted by either chronological age or health status. The end-of-life decisions showed the most striking differences in the willingness to use assistive technologies, revealing older chronically ill participants to have more restrained attitudes towards technology usage than older healthy as well as all younger participants.

CONCLUSIONS

The findings suggest that the benefits of assistive technologies in private or professional care contexts should be communicated and implemented tailored to the respective user group's needs. Moreover, the results allow us to derive practical implications within the geriatric care context.