Metabolism, homeostasis, and aging

The Involvement of Antioxidants in Cognitive Decline and Neurodegeneration: Mens Sana in Corpore Sano

With neurodegenerative disorders being on the rise, a great deal of research from multiple fields is being conducted in order to further knowledge and propose novel therapeutic interventions. Among these investigations, research on the role of antioxidants in contrasting cognitive decline is putting forward interesting and promising results. In this review, we aim to collect evidence that focused on the role of a variety of antioxidants and antioxidant-rich foods in improving or stabilizing cognitive functions, memory, and Alzheimer's disease, the most common neurodegenerative disorder. Specifically, we considered evidence collected on humans, either through longitudinal studies or randomized, placebo-controlled ones, which evaluated cognitive performance, memory abilities, or the progression level of neurodegeneration. Overall, despite a great deal of variety between study protocols, cohorts of participants involved, neuropsychological tests used, and investigated antioxidants, there is a solid trend that suggests that the properties of antioxidants may be helpful in hampering cognitive decline in older people. Thus, the help of future research that will further elucidate the role of antioxidants in neuroprotection will lead to the development of novel interventions that will take into account such findings to provide a more global approach to treating neurodegenerative disorders.

Genetic, Environmental, and Stochastic Components of Lifespan Variability: The Drosophila Paradigm

Lifespan is a complex quantitative trait involving genetic and non-genetic factors as well as the peculiarities of ontogenesis. As with all quantitative traits, lifespan shows considerable variation within populations and between individuals. Drosophila, a favourite object of geneticists, has greatly advanced our understanding of how different forms of variability affect lifespan. This review considers the role of heritable genetic variability, phenotypic plasticity and stochastic variability in controlling lifespan in Drosophila melanogaster. We discuss the major historical milestones in the development of the genetic approach to study lifespan, the breeding of long-lived lines, advances in lifespan QTL mapping, the environmental factors that have the greatest influence on lifespan in laboratory maintained flies, and the mechanisms, by which individual development affects longevity. The interplay between approaches to study ageing and lifespan limitation will also be discussed. Particular attention will be paid to the interaction of different types of variability in the control of lifespan.

Metabolic remodeling in cancer and senescence and its therapeutic implications

Cellular metabolism is a flexible and plastic network that often dictates physiological and pathological states of the cell, including differentiation, cancer, and aging. Recent advances in cancer metabolism represent a tremendous opportunity to treat cancer by targeting its altered metabolism. Interestingly, despite their stable growth arrest, senescent cells - a critical component of the aging process - undergo metabolic changes similar to cancer metabolism. A deeper understanding of the similarities and differences between these disparate pathological conditions will help identify which metabolic reprogramming is most relevant to the therapeutic liabilities of senescence. Here, we compare and contrast cancer and senescence metabolism and discuss how metabolic therapies can be established as a new modality of senotherapy for healthy aging.

The multi-faceted nature of age-associated osteoporosis

Age-associated osteoporosis (AAOP) poses a significant health burden, characterized by increased fracture risk due to declining bone mass and strength. Effective prevention and early treatment strategies are crucial to mitigate the disease burden and the associated healthcare costs. Current therapeutic approaches effectively target the individual contributing factors to AAOP. Nonetheless, the management of AAOP is complicated by the multitude of variables that affect its development. Main intrinsic and extrinsic factors contributing to AAOP risk are reviewed here, including mechanical unloading, nutrient deficiency, hormonal disbalance, disrupted metabolism, cognitive decline, inflammation and circadian disruption. Furthermore, it is discussed how these can be targeted for prevention and treatment. Although valuable as individual targets for intervention, the interconnectedness of these risk factors result in a unique etiology for every patient. Acknowledgement of the multifaceted nature of AAOP will enable the development of more effective and sustainable management strategies, based on a holistic, patient-centered approach.

Energy Regulation in Inflammatory Sarcopenia by the Purinergic System

The purinergic system has a dual role: the maintenance of energy balance and signaling within cells. Adenosine and adenosine triphosphate (ATP) are essential for maintaining these functions. Sarcopenia is characterized by alterations in the control of energy and signaling in favor of catabolic pathways. This review details the association between the purinergic system and muscle and adipose tissue homeostasis, discussing recent findings in the involvement of purinergic receptors in muscle wasting and advances in the use of the purinergic system as a novel therapeutic target in the management of sarcopenia.

Aging, oxidative stress and degenerative diseases: mechanisms, complications and emerging therapeutic strategies

Aging accompanied by several age-related complications, is a multifaceted inevitable biological progression involving various genetic, environmental, and lifestyle factors. The major factor in this process is oxidative stress, caused by an abundance of reactive oxygen species (ROS) generated in the mitochondria and endoplasmic reticulum (ER). ROS and RNS pose a threat by disrupting signaling mechanisms and causing oxidative damage to cellular components. This oxidative stress affects both the ER and mitochondria, causing proteopathies (abnormal protein aggregation), initiation of unfolded protein response, mitochondrial dysfunction, abnormal cellular senescence, ultimately leading to inflammaging (chronic inflammation associated with aging) and, in rare cases, metastasis. RONS during oxidative stress dysregulate multiple metabolic pathways like NF-κB, MAPK, Nrf-2/Keap-1/ARE and PI3K/Akt which may lead to inappropriate cell death through apoptosis and necrosis. Inflammaging contributes to the development of inflammatory and degenerative diseases such as neurodegenerative diseases, diabetes, cardiovascular disease, chronic kidney disease, and retinopathy. The body's antioxidant systems, sirtuins, autophagy, apoptosis, and biogenesis play a role in maintaining homeostasis, but they have limitations and cannot achieve an ideal state of balance. Certain interventions, such as calorie restriction, intermittent fasting, dietary habits, and regular exercise, have shown beneficial effects in counteracting the aging process. In addition, interventions like senotherapy (targeting senescent cells) and sirtuin-activating compounds (STACs) enhance autophagy and apoptosis for efficient removal of damaged oxidative products and organelles. Further, STACs enhance biogenesis for the regeneration of required organelles to maintain homeostasis. This review article explores the various aspects of oxidative damage, the associated complications, and potential strategies to mitigate these effects.

Chronic inflammation and the hallmarks of aging

BACKGROUND

Recently, the hallmarks of aging were updated to include dysbiosis, disabled macroautophagy, and chronic inflammation. In particular, the low-grade chronic inflammation during aging, without overt infection, is defined as "inflammaging," which is associated with increased morbidity and mortality in the aging population. Emerging evidence suggests a bidirectional and cyclical relationship between chronic inflammation and the development of age-related conditions, such as cardiovascular diseases, neurodegeneration, cancer, and frailty. How the crosstalk between chronic inflammation and other hallmarks of aging underlies biological mechanisms of aging and age-related disease is thus of particular interest to the current geroscience research.

SCOPE OF REVIEW

This review integrates the cellular and molecular mechanisms of age-associated chronic inflammation with the other eleven hallmarks of aging. Extra discussion is dedicated to the hallmark of "altered nutrient sensing," given the scope of Molecular Metabolism. The deregulation of hallmark processes during aging disrupts the delicate balance between pro-inflammatory and anti-inflammatory signaling, leading to a persistent inflammatory state. The resultant chronic inflammation, in turn, further aggravates the dysfunction of each hallmark, thereby driving the progression of aging and age-related diseases.

MAIN CONCLUSIONS

The crosstalk between chronic inflammation and other hallmarks of aging results in a vicious cycle that exacerbates the decline in cellular functions and promotes aging. Understanding this complex interplay will provide new insights into the mechanisms of aging and the development of potential anti-aging interventions. Given their interconnectedness and ability to accentuate the primary elements of aging, drivers of chronic inflammation may be an ideal target with high translational potential to address the pathological conditions associated with aging.

The Degradation and Aging of Biological Systems as a Process of Information Loss and Entropy Increase

The problem of the degradation and aging of bioorganisms is herein considered from the viewpoint of statistical physics. Two typical timescales in biological systems-the time of metabolic processes and the time of the life cycle-are used. A kinetic equation describing the small timescales of the systems' characteristic processes in is proposed. Maintaining a biosystem in a time-stable state requires a constant inflow of negative entropy (negentropy). Ratios are proposed to evaluate the aging and degradation of systems in terms of entropy. As an example, the aging of the epithelium is studied. The connection of our approach to the information theory of aging is discussed, as well as theoretical constructions related to the concept of cooperon and its changing with time.

[Modern approaches to developing a system of valid methods for monitoring individual health and maintaining active longevity]

Life expectancy In Russia in 2023, according to preliminary data, exceeded 73 years, returning to the pre-pandemic level. The increase in life expectancy is associated both with an improvement in the quality of medical care In Russia and with a more responsible attitude towards the health of citizens, which is confirmed by an improvement in the quality of nutrition, a decrease in alcohol consumption and an increase in the number of people involved in sports. At the same time, there are many signs of aging, both cellular and molecular, some of the main ones are genome stability, telomere shortening, epigenetic alterations, impaired proteostasis and nutrient recognition, mitochondrial dysfunction, depletion of the stem cell pool and changes in intercellular interactions, extracellular matrix rigidity, as well as retrotransposon activation and chronic inflammation. For these reasons, in modern healthcare, the tasks of preventing premature aging and treating age-related diseases are becoming priorities.

MATERIAL AND METHODS

In total, at the first stage of work (in 2023), we examined 80 people, whose average age was 59.6±0.7 years. When analyzing and assessing data, the study adopted a division into age groups (WHO). The following indicators were studied: HbA1, fructosamine, HDL cholesterol, LDL cholesterol, insulin, homocysteine, C-peptide, TSH, free T4, prolactin, total testosterone, cortisol, arginine, asymmetric dimethylarginine, leptin, TNF-a, ferritin, interleukin 1 and 6, telomere length, creatinine, uric acid and urea.

RESULTS

As a result of the study, it was revealed that the aging process of the body affects many indicators, while the main markers that changed in men aged 18 to 44 years were total testosterone, leptin and telomere length; aged 44 to 60 years - HbA1, fructosamine, HDL cholesterol, homocysteine, C-peptide, total testosterone, leptin and telomere length; from 60 to 75 years - fructosamine, HDL cholesterol and telomere length and for 75-90 years - HbA1, HDL cholesterol, insulin, total testosterone, leptin and telomere length, interleukin 6 and uric acid. In women aged 18 to 44 years, only an increase in leptin was observed against the background of shortening telomere length; at the age of 44 to 60 years, the main markers that changed were total testosterone, leptin and telomere length; for the age group 60-75 years - indicators of HbA1, homocysteine, C-peptide, prolactin, total testosterone and leptin, interleukin 6 and uric acid, telomere length was shorter by only 2%; in the age group of 75-90 years, the main markers that changed were insulin, total testosterone, leptin, interleukin 6, while the indicators of uric acid, urea and telomere length differed from the reference values by 2-4%. Shortening of telomere length in all age groups, both men and women, indicates the presence of signs of premature aging. In an individual analysis, data were obtained on a more dramatic shortening of telomeres in 16 subjects in the presence of impaired glucose tolerance and insulin secretion, especially in comparison with healthy subjects, which was confirmed by the data of glycated hemoglobin (HbA1c), while, with shortening of telomere length, the HbA1 indicator was significantly higher (6.8±0.5) than in individuals with long telomeres and no chronic pathology (5.1±0.4).

CONCLUSION

A system of highly valid methods and panels of markers has been developed that indicate the presence of aging processes, taking into account gender and age characteristics, which can be used to identify premature aging processes, monitor individual health and maintain active longevity, as well as for the prevention of age-associated diseases.