bims-agimec 2024-12-29 papers

bims-agimec

Biomed News

on Aging mechanisms

Issue of 2024–12–29
seven papers selected by
Metin Sökmen, Ankara Üniversitesi

Decoding Brain Development and Aging: Pioneering Insights From MRI Techniques.
The impact of COVID-19 on accelerating of immunosenescence and brain aging.
Micro nutrients as immunomodulators in the ageing population: a focus on inflammation and autoimmunity.
Revealing the secrets of Blue Zones.
Menopause Decoded: What's Happening and How to Manage It.
Reconsidering the usual suspects in age-related hematologic disorders: is stem cell dysfunction a root cause of aging?
Variation in brain aging: A review and perspective on the utility of individualized approaches to the study of functional networks in aging.

Invest Radiol. 2024 Oct 09.

Decoding Brain Development and Aging: Pioneering Insights From MRI Techniques.

Akifumi Hagiwara, Satoru Kamio, Junko Kikuta, Moto Nakaya, Wataru Uchida, Shohei Fujita, Stikov Nikola, Toshiaki Akasahi, Akihiko Wada, Koji Kamagata, Shigeki Aoki.

ABSTRACT: The aging process induces a variety of changes in the brain detectable by magnetic resonance imaging (MRI). These changes include alterations in brain volume, fluid-attenuated inversion recovery (FLAIR) white matter hyperintense lesions, and variations in tissue properties such as relaxivity, myelin, iron content, neurite density, and other microstructures. Each MRI technique offers unique insights into the structural and compositional changes occurring in the brain due to normal aging or neurodegenerative diseases. Age-related brain volume changes encompass a decrease in gray matter and an increase in ventricular volume, associated with cognitive decline. White matter hyperintensities, detected by FLAIR, are common and linked to cognitive impairments and increased risk of stroke and dementia. Tissue relaxometry reveals age-related changes in relaxivity, aiding the distinction between normal aging and pathological conditions. Myelin content, measurable by MRI, changes with age and is associated with cognitive and motor function alterations. Iron accumulation, detected by susceptibility-sensitive MRI, increases in certain brain regions with age, potentially contributing to neurodegenerative processes. Diffusion MRI provides detailed insights into microstructural changes such as neurite density and orientation. Neurofluid imaging, using techniques like gadolinium-based contrast agents and diffusion MRI, reveals age-related changes in cerebrospinal and interstitial fluid dynamics, crucial for brain health and waste clearance. This review offers a comprehensive overview of age-related brain changes revealed by various MRI techniques. Understanding these changes helps differentiate between normal aging and pathological conditions, aiding the development of interventions to mitigate age-related cognitive decline and other symptoms. Recent advances in machine learning and artificial intelligence have enabled novel methods for estimating brain age, offering also potential biomarkers for neurological and psychiatric disorders.

DOI: https://doi.org/10.1097/RLI.0000000000001120
Front Cell Neurosci. 2024 ;18 1471192

The impact of COVID-19 on accelerating of immunosenescence and brain aging.

Ludmila Müller, Svetlana Di Benedetto.

  The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has profoundly impacted global health, affecting not only the immediate morbidity and mortality rates but also long-term health outcomes across various populations. Although the acute effects of COVID-19 on the respiratory system have initially been the primary focus, it is increasingly evident that the virus can have significant impacts on multiple physiological systems, including the nervous and immune systems. The pandemic has highlighted the complex interplay between viral infection, immune aging, and brain health, that can potentially accelerate neuroimmune aging and contribute to the persistence of long COVID conditions. By inducing chronic inflammation, immunosenescence, and neuroinflammation, COVID-19 may exacerbate the processes of neuroimmune aging, leading to increased risks of cognitive decline, neurodegenerative diseases, and impaired immune function. Key factors include chronic immune dysregulation, oxidative stress, neuroinflammation, and the disruption of cellular processes. These overlapping mechanisms between aging and COVID-19 illustrate how the virus can induce and accelerate aging-related processes, leading to an increased risk of neurodegenerative diseases and other age-related conditions. This mini-review examines key features and possible mechanisms of COVID-19-induced neuroimmune aging that may contribute to the persistence and severity of long COVID. Understanding these interactions is crucial for developing effective interventions. Anti-inflammatory therapies, neuroprotective agents, immunomodulatory treatments, and lifestyle interventions all hold potential for mitigating the long-term effects of the virus. By addressing these challenges, we can improve health outcomes and quality of life for millions affected by the pandemic.

Keywords:  COVID-19; brain aging; immunosenescence; inflammaging; long COVID; neuroinflammation; neurological disorders

DOI:  https://doi.org/10.3389/fncel.2024.1471192
Immun Ageing. 2024 Dec 27. 21(1): 88

Micro nutrients as immunomodulators in the ageing population: a focus on inflammation and autoimmunity.

Bhavani Sowndharya Balamurugan, Mathan Muthu Chinnakannu Marimuthu, Vickram Agaram Sundaram, Bharath Saravanan, Prasanth Chandrababu, Hitesh Chopra, Tabarak Malik.

  Immunosenescence, the slow degradation of immune function over time that is a hallmark and driver of aging, makes older people much more likely to be killed by common infections (such as flu) than young adults, but it also contributes greatly to rates of chronic inflammation in later life. Such micro nutrients are crucial for modulating effective immune responses and their deficiencies have been associated with dysfunctional immunity in the elderly. In this review, we specifically focused on the contribution of major micro nutrients (Vitamins A, D and E, Vitamin C; Zinc and Selenium) as immunomodulators in ageing population especially related to inflame-ageing process including autoimmunity. This review will cover these hologenomic interactions, including how micro nutrients can modulate immune cell function and/or cytokine production to benefit their hosts with healthy mucous-associated immunity along with a sustainable immunologic homeostasis. For example, it points out the modulatory effects of vitamin D on both innate and adaptive immunity, with a specific focus on its ability to suppress pro-inflammatory cytokines synthesis while enhancing regulatory T-cell function. In the same context, also zinc is described as important nutrient for thymic function and T-cell differentiation but exhibits immunomodulatory functions by decreasing inflammation. In addition, the review will go over how micro nutrient deficiencies increase systemic chronic low-grade inflammation and, inflammaging as well as actually enhance autoimmune pathologies in old age. It assesses the potential role of additional targeted nutritional supplementation with micro nutrients to counteract these effects, promoting wider immune resilience in older adults. This review collates the current evidence and highlights the role of adequate micro nutrient intake on inflammation and autoimmunity during ageing, providing plausible origins for nutritional interventions to promote healthy immune aging.

Keywords:  Ageing population; Autoimmunity; Immune modulation; Immunosenescence; Inflammation; Micronutrients

DOI:  https://doi.org/10.1186/s12979-024-00492-7
Front Pharmacol. 2024 ;15 1428111

Revealing the secrets of Blue Zones.

N Nuray Ulusu.

  Aging is influenced by cellular senescence mechanisms that are associated with oxidative stress. Oxidative stress is the imbalance between antioxidants and free radicals. This imbalance affects enzyme activities and causes mitochondrial dysfunction. It also slows down cellular energy production and disrupts cellular homeostasis. Additionally, oxidative stress stimulates inflammation, increases the number of point mutations, and alters intercellular communication. It can lead to epigenetic alterations, genomic instability, telomere attrition, and loss of proteostasis. Ultimately, these factors contribute to aging and the development of chronic diseases. Glucose-6-phosphate dehydrogenase (G6PD) is an antioxidant enzyme that protects cells from oxidative and nitrosative damage. It helps restore redox balance, preserve macromolecule function, and rescue cells from cellular senescence, autophagy, and stress-induced apoptosis. G6PD is considered an anti-senescence enzyme. The World Health Organization classifies G6PD variants into five groups based on the enzyme's residual activity. The first four classes are categorized according to the degree of G6PD deficiency, while the fifth class includes variants with enzyme activities greater than normal. Increased G6PD activity does not exhibit clinical manifestations. Consequently, the full spectrum of mutations and the prevalence of increased G6PD activity in the population remain unknown. The world's oldest and healthiest people live in Blue Zones. These comprise isolated populations, and there may be a geographic prevalence of high-activity G6PD variants that protect against oxidative stress-induced senescence. To uncover the secret of centenarians' longevity, additional research is needed to determine whether the hidden factor is the increased activity of the G6PD enzyme.

Keywords:  Blue Zones; glucose-6-phosphate dehydrogenase; glutathione; oxidative stress; senescence

DOI:  https://doi.org/10.3389/fphar.2024.1428111
J Prim Care Community Health. 2024 Jan-Dec;15:15 21501319241307460

Menopause Decoded: What's Happening and How to Manage It.

Brittany Strelow, Danielle O'Laughlin, Taryn Anderson, Jissy Cyriac, Jenny Buzzard, Amber Klindworth.

  Menopause marks a significant transition in a woman's life, typically occurring between the ages of 46 and 55 years, characterized by the cessation of menstruation and a decline in ovarian function. This article provides a comprehensive overview of menopause, examining its physiological, psychological, and social dimensions. It explores the hormonal changes, including decreased levels of estrogen and progesterone, and how these changes contribute to common symptoms such as hot flashes, sleep disturbances, and mood fluctuations. Additionally, it highlights contemporary approaches to management, including lifestyle modifications and hormonal and non-hormonal therapies. By synthesizing current research and clinical insights, this overview aims to enhance understanding and support for women navigating menopause and the healthcare professionals assisting them.

Keywords:  family medicine; menopause; menstrual cycle; primary care; women’s health

DOI:  https://doi.org/10.1177/21501319241307460
Exp Hematol. 2024 Dec 24. pii: S0301-472X(24)00562-9. [Epub ahead of print] 104698

Reconsidering the usual suspects in age-related hematologic disorders: is stem cell dysfunction a root cause of aging?

Foteini Fotopoulou, Esther Rodriguez-Correa, Charles Dussiau, Michael D Milsom.

  Aging exerts a profound impact on the hematopoietic system, leading to increased susceptibility to infections, autoimmune diseases, chronic inflammation, anemia, thrombotic events, and hematologic malignancies. Within the field of experimental hematology, the functional decline of hematopoietic stem cells (HSCs) is often regarded as a primary driver of age-related hematologic conditions. However, aging is clearly a complex multifaceted process involving not only HSCs but also mature blood cells and their interactions with other tissues. This review reappraises an HSC-centric view of hematopoietic aging by exploring how the entire hematopoietic hierarchy, from stem cells to mature cells, contributes to age-related disorders. It highlights the decline of both innate and adaptive immunity, leading to increased susceptibility to infections and cancer, and the rise of autoimmunity as peripheral immune cells undergo aging-induced changes. It explores the concept of "inflammaging," where persistent, low-grade inflammation driven by old immune cells creates a cycle of tissue damage and disease. Additionally, this review delves into the roles of inflammation and homeostatic regulation in age-related conditions such as thrombotic events and anemia, arguing that these issues arise from broader dysfunctions rather than stemming from HSC functional attrition alone. In summary, this review highlights the importance of taking a holistic approach to studying hematopoietic aging and its related pathologies. By looking beyond just stem cells and considering the full spectrum of age-associated changes, one can better capture the complexity of aging and attempt to develop preventative or rejuvenative strategies that better target multiple facets of this process.

Keywords:  CHIP; HSC; Hematopoietic stem cells; Inflammation; aging; anemia; clonal hematopoiesis; immune compromised; inflammaging; myeloid bias

DOI:  https://doi.org/10.1016/j.exphem.2024.104698
Neurobiol Aging. 2024 Dec 07. pii: S0197-4580(24)00202-1. [Epub ahead of print]147 68-87

Variation in brain aging: A review and perspective on the utility of individualized approaches to the study of functional networks in aging.

Diana C Perez, Joanna J Hernandez, Gretchen Wulfekuhle, Caterina Gratton.

  Healthy aging is associated with cognitive decline across multiple domains, including executive function, memory, and attention. These cognitive changes can often influence an individual's ability to function and quality of life. However, the degree to which individuals experience cognitive decline, as well as the trajectory of these changes, exhibits wide variability across people. These cognitive abilities are thought to depend on the coordinated activity of large-scale networks. Like behavioral effects, large variation can be seen in brain structure and function with aging, including in large-scale functional networks. However, tracking this variation requires methods that reliably measure individual brain networks and their changes over time. Here, we review the literature on age-related cognitive decline and on age-related differences in brain structure and function. We focus particularly on functional networks and the individual variation that exists in these measures. We propose that novel individual-centered fMRI approaches can shed new light on patterns of inter- and intra-individual variability in aging. These approaches may be instrumental in understanding the neural bases of cognitive decline.

Keywords:  Brain aging; Brain networks; Cognitive decline; FMRI; Individual differences; Individualized approaches; Precision

DOI:  https://doi.org/10.1016/j.neurobiolaging.2024.11.010