Molecular Mechanisms Of Aging

Aging represents a physiological and per se non-pathological and multifactorial process involving a set of key genes and mechanisms being triggered by different endogenous and exogenous factors. Since aging is a major risk factor in connection with a variety of human disorders, it is increasingly becoming a central topic in biochemical and medical research. The plethora of theories on aging – some of which have been discussed for decades – are neither isolated nor contradictory but instead can be connected in a network of pathways and processes at the cellular and molecular levels. This book summarizes the most prominent and important approaches, focusing on telomeres, DNA damage and oxidative stress as well as on the possible role of nutrition, the interplay between genes and environment (epigenetics) and intracellular protein homeostasis and introduces some genes that have actually extended life spans in animal models. Linking these different determinants of aging with disease, this volume aims to reveal their multiple interdependencies. We see that there is no single “perfect” theory of aging and that instead it is possible to define what the authors call the molecular aging matrix of the cell. A better knowledge of its key mechanisms and the mutual connections between its components will lead to a better understanding of age-associated disorders such as Alzheimer’s disease.

Aging of unicellular and multicellular eukaryotic organisms is a convoluted biological phenomenon, which is manifested as an age-related functional decline caused by progressive dysregulation of certain cellular and organismal processes. Many chronic diseases are associated with human aging. These aging-associated diseases include cardiovascular diseases, chronic obstructive pulmonary disease, chronic kidney disease, diabetes, osteoarthritis, osteoporosis, sarcopenia, stroke, neurodegenerative diseases (including Parkinson’s, Alzheimer’s, and Huntington’s diseases), and many forms of cancer. Studies in yeast, roundworms, fruit flies, fishes, mice, primates, and humans have provided evidence that the major aspects and basic mechanisms of aging and aging-associated pathology are conserved across phyla. The focus of this International Journal of Molecular Sciences Special Issue is on molecular and cellular mechanisms, diagnostics, and therapies and diseases of aging. Fifteen original research and review articles in this Special Issue provide important insights into how various genetic, dietary, and pharmacological interventions can affect certain longevity-defining cellular and organismal processes to delay aging and postpone the onset of age-related pathologies in evolutionarily diverse organisms. These articles outline the most important unanswered questions and directions for future research in the vibrant and rapidly evolving fields of mechanisms of biological aging, aging-associated diseases, and aging-delaying therapies.

Numerous studies had been performed to elucidate the mechanisms of aging and to achieve rejuvenation, with some success reported in recent years. However, at present, the findings from those studies are not sufficient to resolve the issue of aging. This book presents an overview of recent topics on cellular aging and rejuvenation. In the early chapters, the molecular mechanisms of aging via the activities of clock and ion channel proteins, in addition to overall aspects, are discussed. In the latter part, the aging of the skin, immune system, and brain is discussed. This book will prove useful for those studying or developing new drugs to counter the aging process and will encourage the development of novel ideas for rejuvenation.

Our skin changes as we age. It becomes thinner and loses fat, making it less plump and smooth. Clinically, aged skin is characterized by wrinkles, sagging, age spots and dryness. Emphasizing laboratory and clinical research, this book comprehensively describes the molecular mechanisms of human skin-aging and age-related skin diseases. This includes molecular understanding of the development of aging skin and its prevention as well as mechanisms-based clinical rejuvenation. The book also focuses on research to develop mechanisms-based anti-skin-aging products.

This book describes the nature of aging, age-related disorders, and the molecular principles of emerging strategies for anti-aging interventions, while also discussing the discovery of targets for geroprotective drugs. Although significant medical advances in the treatment and eradication of life-threatening conditions such as cardiovascular and infectious disease have been made over the past five decades, the prevalence of age-related disorders still remains high in older populations. Intervening into aging is the next frontier in contemporary medicine, and will be of increasing importance over time, as other sources of poor health are combated more and more successfully. Given the universal interest in anti-aging strategies, the book will appeal to a very broad audience. It addresses a diverse range of anti-aging interventions – including stem cells, autophagy, senolytics, anti-inflammatory methods, and telomerase induction – that will be of interest to scientists and researchers from various disciplines in the life sciences.

The nervous system is a highly complex network of nerves that coordinates actions and sensory information by transmitting signals to and from various parts of the body. Random molecular damage that steadily accumulates with age drives the ageing process at the cellular level. Many molecular mechanisms are involved and exogenous factors, like stress, also play a role in the aging process. The nervous system at the cellular level comprises a special cell called a neuron, which transmits signals to the other cells. Many physical, chemical, or biological changes in the status of neurons characterize brain aging. It is manifested in the form of deterioration in cognitive function and dementia. Dendritic regression in pyramidal neurons, synaptic atrophy, decrease of striatal dopamine receptors, accumulation of fluorescent pigments, cytoskeletal abnormalities, and reactive astrocytes and microglia are the common features of brain aging. The consequence of molecular and cellular alterations in brain aging is characterized by a plethora of anatomical changes, such as significant neuronal loss in hippocampus and neocortex. This book provides comprehensive insights on the molecular and cellular mechanisms of aging. The readers would gain knowledge that would broaden their perspective about this area of study.

Telomere shortening represents one of the basic aspects of ageing and telomere dysfunction could contribute to the accumulation of DNA damage during ageing. This book summarizes evidence and data indicating that telomere dysfunction influences human ageing, diseases and cancer. The book describes our current knowledge on checkpoints that limit cellular lifespan and survival in response to telomere dysfunction. There is special focus on adult stem cells.