Molecular markers of DNA repair and brain metabolism correlate with cognition in centenarians

Regulatory mechanisms and potential therapeutic targets in precancerous lesions of gastric cancer: A comprehensive review

Precancerous lesions of gastric cancer (PLGC) represent a critical pathological stage in the transformation from normal gastric mucosa to gastric cancer (GC). The global incidence of PLGC has been rising over the past few decades, with a trend towards younger onset ages. Increasing evidence suggests that early prevention and treatment of PLGC can effectively reverse the malignant development of gastric mucosal epithelial cells. However, there is currently a lack of effective therapeutic drugs and methods. Recent years have witnessed substantial advancements in PLGC research, with the elucidation of novel regulatory mechanisms offering promising avenues for clinical intervention and drug development. This review aims to delineate potential targets for early prevention and diagnosis of GC while exploring innovative approaches to PLGC management. This article focuses on elucidating the regulatory mechanisms of the inflammatory microenvironment, bile acids (BA), glycolysis, autophagy, apoptosis, ferroptosis, and cellular senescence. We pay particular attention to potential therapeutic targets for PLGC, with the goal of providing insights and theoretical basis for clinical research on PLGC.

Markers of Mitochondrial Function and DNA Repair Associated with Physical Function in Centenarians

Mitochondrial dysfunction and genomic instability are key hallmarks of aging. The aim of this study was to evaluate whether maintenance of physical capacities at very old age is associated with key hallmarks of aging. To investigate this, we measured mitochondrial bioenergetics, mitochondrial DNA (mtDNA) copy number and DNA repair capacity in peripheral blood mononuclear cells from centenarians. In addition, circulating levels of NAD+/NADH, brain-derived neurotrophic factor (BDNF) and carbonylated proteins were measured in plasma and these parameters were correlated to physical capacities. Centenarians without physical disabilities had lower mitochondrial respiration values including ATP production, reserve capacity, maximal respiration and non-mitochondrial oxygen-consumption rate and had higher mtDNA copy number than centenarians with moderate and severe disabilities (p < 0.05). In centenarian females, grip strength had a positive association with mtDNA copy number (p < 0.05), and a borderline positive trend for activity of the central DNA repair enzyme, APE 1 (p = 0.075), while a negative trend was found with circulating protein carbonylation (p = 0.07) in the entire cohort. Lastly, a trend was observed for a negative association between BDNF and activity of daily living disability score (p = 0.06). Our results suggest that mechanisms involved in maintaining mitochondrial function and genomic stability may be associated with maintenance of physical function in centenarians.

New insights into healthy ageing, inflammageing and frailty using metabolomics

Human ageing is a normal process and does not necessarily result in the development of frailty. A mix of genetic, environmental, dietary, and lifestyle factors can have an impact on ageing, and whether an individual develops frailty. Frailty is defined as the loss of physiological reserve both at the physical and cellular levels, where systemic processes such as oxidative stress and inflammation contribute to physical decline. The newest "omics" technology and systems biology discipline, metabolomics, enables thorough characterisation of small-molecule metabolites in biological systems at a particular time and condition. In a biological system, metabolites-cellular intermediate products of metabolic reactions-reflect the system's final response to genomic, transcriptomic, proteomic, epigenetic, or environmental alterations. As a relatively newer technique to characterise metabolites and biomarkers in ageing and illness, metabolomics has gained popularity and has a wide range of applications. We will give a comprehensive summary of what is currently known about metabolomics in studies of ageing, with a focus on biomarkers for frailty. Metabolites related to amino acids, lipids, carbohydrates, and redox metabolism may function as biomarkers of ageing and/or frailty development, based on data obtained from human studies. However, there is a complexity that underpins biological ageing, due to both genetic and environmental factors that play a role in orchestrating the ageing process. Therefore, there is a critical need to identify pathways that contribute to functional decline in people with frailty.

SuperAgers and centenarians, dynamics of healthy ageing with cognitive resilience

Graceful healthy ageing and extended longevity is the most desired goal for human race. The process of ageing is inevitable and has a profound impact on the gradual deterioration of our physiology and health since it triggers the onset of many chronic conditions like dementia, osteoporosis, diabetes, arthritis, cancer, and cardiovascular disease. However, some people who lived/live more than 100 years called 'Centenarians" and how do they achieve their extended lifespans are not completely understood. Studying these unknown factors of longevity is important not only to establish a longer human lifespan but also to manage and treat people with shortened lifespans suffering from age-related morbidities. Furthermore, older adults who maintain strong cognitive function are referred to as "SuperAgers" and may be resistant to risk factors linked to cognitive decline. Investigating the mechanisms underlying their cognitive resilience may contribute to the development of therapeutic strategies that support the preservation of cognitive function as people age. The key to a long, physically, and cognitively healthy life has been a mystery to scientists for ages. Developments in the medical sciences helps us to a better understanding of human physiological function and greater access to medical care has led us to an increase in life expectancy. Moreover, inheriting favorable genetic traits and adopting a healthy lifestyle play pivotal roles in promoting longer and healthier lives. Engaging in regular physical activity, maintaining a balanced diet, and avoiding harmful habits such as smoking contribute to overall well-being. The synergy between positive lifestyle choices, access to education, socio-economic factors, environmental determinants and genetic supremacy enhances the potential for a longer and healthier life. Our article aims to examine the factors associated with healthy ageing, particularly focusing on cognitive health in centenarians. We will also be discussing different aspects of ageing including genomic instability, metabolic burden, oxidative stress and inflammation, mitochondrial dysfunction, cellular senescence, immunosenescence, and sarcopenia.

Roles of NAD+ in Health and Aging

NAD+, the essential metabolite involved in multiple reactions such as the regulation of cellular metabolism, energy production, DNA repair, mitophagy and autophagy, inflammation, and neuronal function, has been the subject of intense research in the field of aging and disease over the last decade. NAD+ levels decline with aging and in some age-related diseases, and reduction in NAD+ affects all the hallmarks of aging. Here, we present an overview of the discovery of NAD+, the cellular pathways of producing and consuming NAD+, and discuss how imbalances in the production rate and cellular request of NAD+ likely contribute to aging and age-related diseases including neurodegeneration. Preclinical studies have revealed great potential for NAD+ precursors in promotion of healthy aging and improvement of neurodegeneration. This has led to the initiation of several clinical trials with NAD+ precursors to treat accelerated aging, age-associated dysfunctions, and diseases including Alzheimer's and Parkinson's. NAD supplementation has great future potential clinically, and these studies will also provide insight into the mechanisms of aging.

Improving Cognitive Function with Nutritional Supplements in Aging: A Comprehensive Narrative Review of Clinical Studies Investigating the Effects of Vitamins, Minerals, Antioxidants, and Other Dietary Supplements

Cognitive impairment and dementia are burgeoning public health concerns, especially given the increasing longevity of the global population. These conditions not only affect the quality of life of individuals and their families, but also pose significant economic burdens on healthcare systems. In this context, our comprehensive narrative review critically examines the role of nutritional supplements in mitigating cognitive decline. Amidst growing interest in non-pharmacological interventions for cognitive enhancement, this review delves into the efficacy of vitamins, minerals, antioxidants, and other dietary supplements. Through a systematic evaluation of randomized controlled trials, observational studies, and meta-analysis, this review focuses on outcomes such as memory enhancement, attention improvement, executive function support, and neuroprotection. The findings suggest a complex interplay between nutritional supplementation and cognitive health, with some supplements showing promising results and others displaying limited or context-dependent effectiveness. The review highlights the importance of dosage, bioavailability, and individual differences in response to supplementation. Additionally, it addresses safety concerns and potential interactions with conventional treatments. By providing a clear overview of current scientific knowledge, this review aims to guide healthcare professionals and researchers in making informed decisions about the use of nutritional supplements for cognitive health.

The NADase CD38 may not dictate NAD levels in brain mitochondria of aged mice but regulates hydrogen peroxide generation

Aging is a time-related functional decline that affects many species. One of the hallmarks of aging is mitochondrial dysfunction, which leads to metabolic decline. The NAD decline during aging, in several tissues, correlates with increase in NADase activity of CD38. Knock out or pharmacological inhibition of CD38 activity can rescue mitochondrial function in several tissues, however, the role of CD38 in controlling NAD levels and metabolic function in the aging brain is unknown. In this work, we investigated CD38 NADase activity controlling NAD levels and mitochondrial function in mice brain with aging. We demonstrate that NADase activity of CD38 does not dictate NAD total levels in brain of aging mice and does not control mitochondrial oxygen consumption nor other oxygen parameters markers of mitochondrial dysfunction. However, for the first time we show that CD38 regulates hydrogen peroxide (H2O2) generation, one of the reactive oxygen species (ROS) in aging brain, through regulation of pyruvate dehydrogenase and alfa-ketoglutarate dehydrogenase, as mitochondria H2O2 leakage sites. The effect may be related to mitochondrial calcium handling differences in CD38 absence. Our study highlights a novel role of CD38 in brain energy metabolism and aging.

Sting and p53 DNA repair pathways are compromised in Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of dementia. A common finding in AD is DNA damage. Double-strand DNA breaks (DSBs) are particularly hazardous to neurons because their post-mitotic state forces neurons to rely on error-prone and potentially mutagenic mechanisms to repair DNA breaks. However, it remains unclear whether DNA damage results from increased DNA damage or failure of DNA repair. Oligomerization of the tumor suppressor protein p53 is an essential part of DSB repair, and p53 phosphorylated on S15 is an indicator of DNA damage. We report that the monomer:dimer ratio of phosphorylated (S15) p53 is increased by 2.86-fold in temporal lobes of AD patients compared to age-matched controls, indicating that p53 oligomerization is compromised in AD. In vitro oxidation of p53 with 100 nM H2O2 produced a similar shift in the monomer:dimer ratio. A COMET test showed a higher level of DNA degradation in AD consistent with double-strand DNA damage or inhibition of repair. Protein carbonylation was also elevated (190% of control), indicating elevated oxidative stress in AD patients. Levels of the DNA repair support protein 14-3-3σ, γ-H2AX, a phosphorylated histone marking double strand DNA breaks, and phosphorylated ataxia telangiectasia mutated (ATM) protein were all increased. cGAS-STING-interferon signaling was impaired in AD and was accompanied by a depletion of STING protein from Golgi and a failure to elevate interferon despite the presence of DSBs. The results suggest that oxidation of p53 by ROS could inhibit the DDR and decrease its ability to orchestrate DSB repair by altering the oligomerization state of p53. The failure of immune-stimulated DNA repair may contribute to cell loss in AD and suggests new therapeutic targets for AD.

Longevity, Centenarians and Modified Cellular Proteodynamics

We have shown before that at least one intracellular proteolytic system seems to be at least as abundant in the peripheral blood lymphocytes of centenarians as in the same cells of young individuals (with the cells of the elderly population showing a significant dip compared to both young and centenarian cohorts). Despite scarce published data, in this review, we tried to answer the question how do different types of cells of longevous people-nonagenarians to (semi)supercentenarians-maintain the quality and quantity of their structural and functional proteins? Specifically, we asked if more robust proteodynamics participate in longevity. We hypothesized that at least some factors controlling the maintenance of cellular proteomes in centenarians will remain at the "young" level (just performing better than in the average elderly). In our quest, we considered multiple aspects of cellular protein maintenance (proteodynamics), including the quality of transcribed DNA, its epigenetic changes, fidelity and quantitative features of transcription of both mRNA and noncoding RNAs, the process of translation, posttranslational modifications leading to maturation and functionalization of nascent proteins, and, finally, multiple facets of the process of elimination of misfolded, aggregated, and otherwise dysfunctional proteins (autophagy). We also included the status of mitochondria, especially production of ATP necessary for protein synthesis and maintenance. We found that with the exception of the latter and of chaperone function, practically all of the considered aspects did show better performance in centenarians than in the average elderly, and most of them approached the levels/activities seen in the cells of young individuals.

Blood-Derived Progenitor Cells Are Depleted in Older Adults with Cognitive Impairment: A Role for Vascular Resilience?

BACKGROUND

Depletion of blood-derived progenitor cells, including so called "early endothelial progenitor cells", has been observed in individuals with early stage Alzheimer's disease relative to matched older control subjects. These findings could implicate the loss of angiogenic support from hematopoietic progenitors or endothelial progenitors in cognitive dysfunction.

OBJECTIVE

To investigate links between progenitor cell proliferation and mild levels of cognitive dysfunction.

METHODS

We conducted in vitro studies of blood-derived progenitor cells using blood samples from sixty-five older adults who were free of stroke or dementia. Peripheral blood mononuclear cells from venous blood samples were cultured in CFU-Hill media and the number of colony forming units were counted after 5 days in vitro. Neuropsychological testing was administered to all participants.

RESULTS

Fewer colony forming units were observed in samples from older adults with a Clinical Dementia Rating global score of 0.5 versus 0. Older adults whose samples developed fewer colony forming units exhibited worse performance on neuropsychological measures of memory, executive functioning, and language ability.

CONCLUSION

These data suggest blood progenitors may represent a vascular resilience marker related to cognitive dysfunction in older adults.

Aging and aging-related diseases: from molecular mechanisms to interventions and treatments

Aging is a gradual and irreversible pathophysiological process. It presents with declines in tissue and cell functions and significant increases in the risks of various aging-related diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. Although the development of modern medicine has promoted human health and greatly extended life expectancy, with the aging of society, a variety of chronic diseases have gradually become the most important causes of disability and death in elderly individuals. Current research on aging focuses on elucidating how various endogenous and exogenous stresses (such as genomic instability, telomere dysfunction, epigenetic alterations, loss of proteostasis, compromise of autophagy, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, deregulated nutrient sensing) participate in the regulation of aging. Furthermore, thorough research on the pathogenesis of aging to identify interventions that promote health and longevity (such as caloric restriction, microbiota transplantation, and nutritional intervention) and clinical treatment methods for aging-related diseases (depletion of senescent cells, stem cell therapy, antioxidative and anti-inflammatory treatments, and hormone replacement therapy) could decrease the incidence and development of aging-related diseases and in turn promote healthy aging and longevity.