Mitochondrial dysfunction and its association with age-related disorders

Mediated roles of oxidative stress and kidney function to leukocyte telomere length and prognosis in chronic kidney disease

BACKGROUND

Few studies have focused on the correlation between leukocyte telomere length (LTL) and cancer-related mortality or identified potential factors that mediate the relationship between LTL and mortality among chronic kidney disease (CKD) patients. Our study aimed to explore the associations between LTL and all-cause and cause-specific mortality and to identify the underlying mediators.

METHODS

CKD patients were obtained from the National Health and Nutrition Examination Survey (NHANES) 1999-2002. Cox regression analysis and restricted cubic spline analysis were used to explore the associations between LTL and all-cause or specific-cause mortality and their nonlinear connections. Stratified analyses were executed to assess the relationships among the different subgroups. The latent mediated factors were confirmed using mediation analysis. Sensitivity analyses were used to evaluate the robustness of our findings.

RESULTS

Longer LTL associated with the lower risk of all-cause mortality, cardiovascular disease (CVD) and cancer-related mortality, and U-shaped relationships were detected. Patients younger than 65 years with greater LTL or who had hypertension had better prognoses. Age and history of hypertension were associated with LTL and overall mortality. In addition, estimated glomerular filtration rate (eGFR), albumin, and total bilirubin mediated the association, and the proportions of indirect effects were 7.81%, 3.77%, and 2.50%, respectively. Six sensitivity analyses confirmed the robustness of our findings.

CONCLUSIONS

This study revealed that LTL was a protective factor for survival among patients with CKD and emphasized the mediating roles of oxidative stress and kidney function.

ED-71 ameliorates OVX-induced osteoporosis by regulating calcium homeostasis and SIRT1-mediated mitochondrial function, alleviating osteoblast senescence and suppressing osteoclastogenesis

Osteoporosis arising from estrogen deficiency is characterized by oxidative stress and cellular senescence accompanied by calcium loss and disrupted bone metabolism. The paracrine interaction between osteoblasts and osteoclasts, along with the ratio of receptor activator of nuclear factor-κB ligand (RANKL) to osteoprotegerin (OPG), play a pivotal role in maintaining bone homeostasis. Eldecalcitol (ED-71), a novel active form of vitamin D, can reduce the ratio of RANKL to OPG in osteoblasts. In this study, an ovariectomized (OVX) rat model was established in vivo, and a cell model was constructed in vitro using H₂O₂ to explore the specific mechanism by which ED-71 improved the release of RANKL/OPG in senescent osteoblasts. Mitochondrial dysfunction and calcium imbalance were identified as significant factors. Under oxidative stress conditions, ED-71 alleviated endoplasmic reticulum (ER) stress by decreasing the ratio of phosphorylated protein kinase R-like ER kinase (P-PERK/PERK), and augmented the expression levels of sarcoplasmic reticulum/endoplasmic reticulum calcium ATPase 2 (SCERA2) thereby promoting calcium uptake by the ER, enhancing ER calcium influx, and effectively ameliorating calcium homeostasis between the ER and mitochondria. Consequently, it mitigates mitochondrial calcium overload and associated dysfunction. In contrast, ED-71 increased the expression of silent information regulator 1 (SIRT1) and phosphorylated AMP-activated protein kinase (P-AMPK). This alleviates mitochondrial dysfunction and promotes adenosine triphosphate (ATP). The combined effects of these two factors synergistically contribute to the improvement in osteoblast senescence.

Remodeling, compartmentalization, and degradation: a trifecta for organelle quality control during gametogenesis

The key to healthy offspring production lies in the accurate inheritance of components from progenitor germ cells during gametogenesis. Along with genetic material, precise regulation of organelle inheritance is vital for gamete health and embryonic development, especially in aged organisms, where organelle function declines and damage accumulates. In these cases, removing age-related organellar defects in precursor cells is crucial for successful reproduction. The single-celled organism Saccharomyces cerevisiae shares striking similarities with more complex organisms: like metazoan cells, yeast accumulate organelle damage with age, yet can still produce damage-free gametes with a reset lifespan. Recent studies show that organelles undergo significant reorganization during yeast gametogenesis, and similar remodeling occurs in metazoans, suggesting common strategies for maintaining gamete quality. This review summarizes organellar reorganization during gametogenesis in yeast and how it aids in clearing age-related cellular damage. We also explore organellar remodeling in multicellular organisms and discuss the potential mechanisms and biological benefits of meiotic organellar reshaping.

Cannabinol (CBN) alleviates age-related cognitive decline by improving synaptic and mitochondrial health

Age-related cognitive decline and neurodegenerative diseases, such as Alzheimer's disease, represent major global health challenges, particularly with an aging population. Mitochondrial dysfunction appears to play a central role in the pathophysiology of these conditions by driving redox dysregulation and impairing cellular energy metabolism. Despite extensive research, effective therapeutic options remain limited. Cannabinol (CBN), a cannabinoid previously identified as a potent inhibitor of oxytosis/ferroptosis through mitochondrial modulation, has demonstrated promising neuroprotective effects. In cell culture, CBN targets mitochondria, preserving mitochondrial membrane potential, enhancing antioxidant defenses and regulating bioenergetic processes. However, the in vivo therapeutic potential of CBN, particularly in aging models, has not been thoroughly explored. To address this gap, this study investigated the effects of CBN on age-associated cognitive decline and metabolic dysfunction using the SAMP8 mouse model of accelerated aging. Our results show that CBN significantly improves spatial learning and memory, with more pronounced cognitive benefits observed in female mice. These cognitive improvements are accompanied by sex-specific changes in metabolic parameters, such as enhanced oxygen consumption and energy expenditure. Mechanistically, CBN modulates key regulators of mitochondrial dynamics, including mitofusin 2 (MFN2) and dynamin-related protein 1 (DRP1), while upregulating markers of mitochondrial biogenesis including mitochondrial transcription factor A (TFAM) and translocase of outer mitochondrial membrane 20 (TOM20). Additionally, CBN upregulates key synaptic proteins involved in vesicle trafficking and postsynaptic signaling suggesting that it enhances synaptic function and neurotransmission, further reinforcing its neuroprotective effects. This study provides in vivo evidence supporting CBN's potential to mitigate age-related cognitive and metabolic dysfunction, with notable sex-specific effects, highlighting its promise for neurodegenerative diseases and cognitive decline.

Fungal Bioactive Compounds as Emerging Therapeutic Options for Age-Related Neurodegenerative Disorders

Aging is a complex biological process characterized by progressive multiorgan deterioration that compromises the quality of life. Unhealthy aging often associates with cognitive decline and motor-neurological disorders including Alzheimer's disease, Parkinson's disease, and Huntington's disease. Genetic, environmental, and lifestyle factors, which include dietary habits, interact with aging and influence brain health, thus having an impact on the development of neurodegenerative disorders. In this context, fungal-derived bioactive compounds have emerged as promising neuroprotective agents due to their diverse biological properties that include antioxidative, anti-inflammatory, pro-autophagic, and neurotrophic effects. Key fungal metabolites, including polysaccharides, terpenoids, alkaloids, and phenolic compounds have been shown to modulate neuroinflammatory pathways, enhance neuronal survival, stimulate protective autophagy, and promote synaptic plasticity. Still, challenges related to their bioavailability, standardization, and clinical translation remain unresolved. Future deep research will be crucial to unlocking the full therapeutic potential of fungal-derived neuroprotective compounds. This review examines the potential therapeutic role of fungal metabolites, providing a comparative evaluation with a focus on their mechanisms of action in promoting brain health and longevity.

Structural characterizations and antiaging activities of hydrolyzed low-molecular-weight polysaccharides from Polygoni Multiflori Radix Praeparata

Natural polysaccharides as the primary active components derived from herbal medicine often face challenges due to their large molecular weights, varying chemical structures and poor bioavailability, which significantly restrict their bioactive mechanism investigation and clinical applications. To improve the bioavailability and clarify the antiaging mechanism of polysaccharides from Polygoni Multiflori Radix Praeparata, the high-molecular-weight polysaccharides (PRP) were hydrolyzed into two low-molecular-weight fractions (PRP1 and PRP2) by hydrogen peroxide-ascorbic acid method. The results of structural characterization showed that they were glucans with the molecular weights of 13.43 kDa and 5.97 kDa, respectively. Compared with PRP and PRP1, PRP2 exhibited the most potent antiaging activity in D-galactose-treated T lymphocytes, attributed to its shorter chain length and lower molecular weight. Furthermore, oral administration with PRP2 not only decreased the levels of senescence-associated secretory phenotype (SASP)-related inflammatory cytokines, elevated the counts of T cells, NK cells, and macrophages in the blood, but also reduced the expressions of p16 and p21 proteins in spleen tissues of naturally aged C57BL/6J mice and two fast-aging (ERCC2+/- and TERT-/-) mice. Mechanistically, PRP2 competitively bound with Keap1 and subsequently activated Nrf2/HO-1 pathway. Therefore, PRP2 could be explored as a potential candidate for treatment of age-related diseases and overall aging.

The Insertion Domain of Mti2 Facilitates the Association of Mitochondrial Initiation Factors with Mitoribosomes in Schizosaccharomyces pombe

Translation initiation in mitochondria involves unique mechanisms distinct from those in the cytosol or in bacteria. The Schizosaccharomyces pombe mitochondrial translation initiation factor 2 (Mti2) is the ortholog of human MTIF2, which plays a vital role in synthesizing proteins in mitochondria. Here, we investigate the insertion domain of Mti2, which stabilizes its interaction with the ribosome and is crucial for efficient translation initiation. Our results show that the insertion domain is critical for the proper folding and function of Mti2. The absence of the insertion domain disrupts cell growth and affects the expression of genes encoded by mitochondrial DNA. Additionally, we show that Mti2 physically interacts with the small subunits of mitoribosomes (mtSSU), and deletion of the insertion domain dissociates mitochondrial initiation factors from the mitoribosome, reducing the efficiency of mitochondrial translation. Altogether, these findings highlight the conserved role of the insertion domain in facilitating translation initiation in fission yeast and thus reveal shared principles of mitochondrial translation initiation in both fission yeast and humans.

Signal Converter-Based Therapy Platform Promoting Aging Bone Healing by Improving Permeability of the Mitochondrial Membrane

The aging microenvironment promotes persistent inflammation and loss of intrinsic regenerative capacity. These are major obstacles to effective bone tissue repair in older adults. This study aims to explore how physical thermal stimulation can effectively delay the bone marrow mesenchymal stem cells (BMSCs) aging process. Based on this, an implantable physical signal-converter platform is designed as a therapeutic system that enables stable heat signals at the bone injury site under ultrasound stimulation (US). It is found that the therapeutic platform controllably reduces the mitochondrial outer membrane permeabilization of aging BMSCs, bidirectionally inhibiting mitochondrial reactive oxygen species and mitochondrial DNA (mtDNA) leakage. The leakage ratio of mtDNA decreases by 22.7%. This effectively mitigates the activation of the cGAS-STING pathway and its downstream NF-κB signaling induced by oxidative stress in aging BMSCs, thereby attenuating the pathological advancement of chronic inflammation. Thus, it effectively restores the metabolism and osteogenic differentiation of aging BMSCs in vitro, which is further confirmed in a rat model. In the GMPG/US group, the bone mineral density increases 2-3 times at 4 weeks in the rats femoral defect model. Therefore, this ultrasound-based signal-conversion platform provides a promising strategy for aging bone defect repair.

The role of irisin in exercise-induced muscle and metabolic health: a narrative review

Irisin, a myokine released during physical exercise, has emerged as a key mediator of muscle health and metabolic regulation. This review synthesizes current evidence on how aerobic exercise stimulates irisin release and its subsequent effects, including enhanced muscle mass, strength, and recovery. Additionally, irisin promotes the browning of white adipose tissue, improving fat metabolism and glucose regulation. These adaptations position irisin as a promising therapeutic target for preventing metabolic disorders and optimizing exercise protocols. By exploring human studies and mechanistic insights, this review underscores irisin's potential to address global health challenges, such as obesity and type 2 diabetes, while advancing strategies for personalized exercise interventions.

Environmental Health Is Overlooked in Longevity Research

Aging is a multifactorial process influenced by genetic predisposition and lifestyle choices. Environmental exposures are too often overlooked. Environmental pollutants-ranging from airborne particulate matter and heavy metals to endocrine disruptors and microplastics-accelerate biological aging. Oxidative stress is a major molecular initiating event, driving inflammation and toxicity across biological levels. We detail the mechanisms by which pollutants enhance reactive oxygen species (ROS) production. This oxidative stress inflicts damage on DNA, proteins, and lipids, accelerating telomere shortening, dysregulating autophagy, and ultimately driving epigenetic age acceleration. For instance, exposure to polycyclic aromatic hydrocarbons, benzene, and pesticides has been associated with increased DNA methylation age. Early-life exposures and lifestyle factors such as tobacco and alcohol consumption further contribute to accelerated biological aging. The cumulative loss of healthy life years caused by these factors can conceivably reach between 5 and 10 years per person. Addressing pollutant-induced accelerated aging through regulatory measures, lifestyle changes, and therapeutic interventions is essential to mitigate their detrimental impacts, ultimately extending healthspan and improving quality of life in aging populations.

Reversing Oxinflammation Associated with Glycative Stress and Formation of Advanced Glycation End Products with a Dietary Supplement Containing Rosemary Extract

Objective

Skin aging is accelerated by glycative stress, which promotes the accumulation of advanced glycation end products (AGEs) and impairs the extracellular matrix. A randomized, double-blinded, placebo-controlled trial evaluated a dietary supplement containing rosemary extract (BioR), demonstrating tissular and visible improvements in skin quality. The data reported herein evaluated markers associated with glycative stress and AGEs from skin biopsies and tape strips obtained following dietary supplement use.

Methods

Female participants (N=104), aged 40 to 65 years, with moderate-to-severe skin dullness and roughness/texture, and mild-to-moderate erythema, pore size, and uneven pigmentation were randomized to BioR (n=52) or placebo ([PLB] n=52). Capsules were taken with food over 12 weeks. Subjects (n=16, BioR; n=16, PLB) underwent 3mm punch biopsies (volar upper arm) and tape stripping (16 tape strips, each; volar forearm) at baseline and 12 weeks for analysis of 4-hydroxynonenal protein adducts (4HNE [oxidative stress marker]) and AGEs.

Results

Immunohistochemistry and ELISA revealed that levels of 4HNE protein adducts were significantly decreased from baseline in the BioR versus PLB group (p<0.005; biopsies) and significantly decreased from baseline in the BioR group alone (p<0.05; tape strips) at 12 weeks. Significant reductions in AGEs occurred in the BioR versus PLB group (p<0.005; biopsies) at 12 weeks. No significant changes from baseline occurred in 4HNE protein adduct levels or AGEs in the PLB group.

Conclusion

After 12 weeks, a dietary supplement containing rosemary extract led to significant reductions in a marker associated with oxidative stress, a component of glycation, and AGEs versus placebo in skin in addition to visible improvements in skin quality.

Endothelial Colony-Forming Cells (ECFCs) in cerebrovascular aging: Focus on the pathogenesis of Vascular Cognitive Impairment and Dementia (VCID), and treatment prospects

Endothelial colony-forming cells (ECFCs), a unique endothelial progenitor subset, are essential for vascular integrity and repair, providing significant regenerative potential. Recent studies highlight their role in cerebrovascular aging, particularly in the pathogenesis of vascular cognitive impairment and dementia (VCID). Aging disrupts ECFC functionality through mechanisms such as oxidative stress, chronic inflammation, and cellular senescence, leading to compromised vascular repair and reduced neurovascular resilience. ECFCs influence key cerebrovascular processes, including neurovascular coupling (NVC), blood-brain barrier (BBB) integrity, and vascular regeneration, which are critical for cognitive health. Age-related decline in ECFC quantity and functionality contributes to vascular rarefaction, diminished cerebral blood flow (CBF), and BBB permeability-processes that collectively exacerbate cognitive decline. This review delves into the multifaceted role of ECFCs in cerebrovascular aging and underscores their potential as therapeutic targets in addressing age-related vascular dysfunctions, presenting new directions for mitigating the effects of aging on brain health.

Suppressing the Aging Phenotype of Mesenchymal Stromal Cells: Are We Ready for Clinical Translation?

Mesenchymal stem/stromal cells (MSCs) are involved in the maintenance and regeneration of a large variety of tissues due to their stemness and multi-lineage differentiation capability. Harnessing these advantageous features, a flurry of clinical trials have focused on MSCs to treat different pathologies, but only few protocols have received regulatory approval so far. Among the various causes hindering MSCs' efficacy is the emergence of cellular senescence, which has been correlated with specific characteristics, such as morphological and epigenetic alterations, DNA damage, ROS production, mitochondrial dysfunction, telomere shortening, non-coding RNAs, loss of proteostasis, and a peculiar senescence-associated secretory phenotype. Several strategies have been investigated for delaying or even hopefully reverting the onset of senescence, as assessed by the senescent phenotype of MSCs. Here, the authors reviewed the most updated literature on the potential causes of senescence, with a particular emphasis on the current and future therapeutic approaches aimed at reverting senescence and/or extending the functional lifespan of stem cells.

Oxidative stress and cell senescence as drivers of ageing: Chicken and egg

Oxidative stress and cell senescence are both important drivers of ageing and age-associated disease and disability. In vitro, they are closely interconnected in a chicken-and-egg relationship: Not only is oxidative stress an important cause of cell senescence, but senescent cells are also sources of oxidative stress, obscuring cause-effect relationships during the ageing process. We hypothesize that cell senescence is a significant cause of tissue and systemic oxidative stress during ageing. This review aims to critically summarize the available evidence for this hypothesis. After summarizing the cellular feedback mechanisms that make oxidative stress an integral part of the senescent phenotype, it critically reviews the existing evidence for a role of senescent cells as causes of oxidative stress during mammalian ageing in vivo, focussing on results from intervention experiments. It is concluded that while the available data are in agreement with this hypothesis, they are still too scarce to support a robust conclusion.

Antisenescence Expansion of Mesenchymal Stem Cells Using Piezoelectric β-Poly(vinylidene fluoride) Film-Based Culture

Regenerative therapies based on mesenchymal stem cells (MSCs) show promise in treating a wide range of disorders. However, the replicative senescence of MSCs during in vitro expansion poses a challenge to obtaining a substantial quantity of high-quality MSCs. In this investigation, a piezoelectric β-poly(vinylidene fluoride) film-based culture plate (β-CP) was developed with an antisenescence effect on cultured human umbilical cord-derived MSCs. Compared to traditional tissue culture plates (TCPs) and α-poly(vinylidene fluoride) film-based culture plates, the senescence markers of p21, p53, interleukin-6 and insulin-like growth factor-binding protein-7, stemness markers of OCT4 and NANOG, and telomere length of MSCs cultured on β-CPs were significantly improved. Additionally, MSCs at passage 18 cultured on β-CPs showed significantly better multipotency and pro-angiogenic capacities in vitro, and higher wound healing abilities in a mouse model. Mechanistically, β-CPs rejuvenated senescent MSCs by improving mitochondrial functions and mitigating oxidative and glycoxidative stresses. Overall, this study presents β-CPs as a promising approach for efficient and straightforward antisenescence expansion of MSCs while preserving their stemness, thereby holding great potential for large-scale production of MSCs for clinical application in cell therapies.

Considering Biomarkers of Neurodegeneration in Alzheimer's Disease: The Potential of Circulating Cell-Free DNA in Precision Neurology

Neurodegenerative diseases, such as Alzheimer's disease (AD), are a growing public health crisis, exacerbated by an aging global population and the lack of effective early disease-modifying therapies. Early detection of neurodegenerative disorders is critical to delaying symptom onset and mitigating disease progression, but current diagnostic tools often rely on detecting pathology once clinical symptoms have emerged and significant neuronal damage has already occurred. While disease-specific biomarkers, such as amyloid-beta and tau in AD, offer precise insights, they are too limited in scope for broader neurodegeneration screening for these conditions. Conversely, general biomarkers like neurofilament light chain (NfL) provide valuable staging information but lack targeted insights. Circulating cell-free DNA (cfDNA), released during cell death, is emerging as a promising biomarker for early detection. Derived from dying cells, cfDNA can capture both general neurodegenerative signals and disease-specific insights, offering multi-layered genomic and epigenomic information. Though its clinical potential remains under investigation, advances in cfDNA detection sensitivity, standardized protocols, and reference ranges could establish cfDNA as a valuable tool for early screening. cfDNA methylation signatures, in particular, show great promise for identifying tissue-of-origin and disease-specific changes, offering a minimally invasive biomarker that could transform precision neurology. However, further research is required to address technological challenges and validate cfDNA's utility in clinical settings. Here, we review recent work assessing cfDNA as a potential early biomarker in AD. With continued advances, cfDNA could play a pivotal role in shifting care from reactive to proactive, improving diagnostic timelines and patient outcomes.

Metabolic-Associated Fatty Liver Disease: The Influence of Oxidative Stress, Inflammation, Mitochondrial Dysfunctions, and the Role of Polyphenols

Metabolic-Associated Fatty Liver Disease (MAFLD) is a clinical-pathological scenario that occurs due to the accumulation of triglycerides in hepatocytes which is considered a significant cause of liver conditions and contributes to an increased risk of death worldwide. Even though the possible causes of MAFLD can involve the interaction of genetics, hormones, and nutrition, lifestyle (diet and sedentary lifestyle) is the most influential factor in developing this condition. Polyphenols comprise many natural chemical compounds that can be helpful in managing metabolic diseases. Therefore, the aim of this review was to investigate the impact of oxidative stress, inflammation, mitochondrial dysfunction, and the role of polyphenols in managing MAFLD. Some polyphenols can reverse part of the liver damage related to inflammation, oxidative stress, or mitochondrial dysfunction, and among them are anthocyanin, baicalin, catechin, curcumin, chlorogenic acid, didymin, epigallocatechin-3-gallate, luteolin, mangiferin, puerarin, punicalagin, resveratrol, and silymarin. These compounds have actions in reducing plasma liver enzymes, body mass index, waist circumference, adipose visceral indices, lipids, glycated hemoglobin, insulin resistance, and the HOMA index. They also reduce nuclear factor-KB (NF-KB), interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), blood pressure, liver fat content, steatosis index, and fibrosis. On the other hand, they can improve HDL-c, adiponectin levels, and fibrogenesis markers. These results show that polyphenols are promising in the prevention and treatment of MAFLD.