Cell Death, Inflammation and Oxidative Stress in Neurodegenerative Diseases


Book Description

Neurogenerative diseases encompass very different pathologies, which can be demyelinating or nondemyelinating, but which have common mechanisms such as cell death, oxidative stress and inflammation. A better understanding of these mechanisms allows the search for biomarkers and targets for new therapies. This special issue brings together different data on Alzheimer's disease, Parkinson's disease, and multiple sclerosis, detailing the mechanisms of cell death (necroptosis, ferroptosis), oxidative stress and inflammation but also the possibilities of neuroprotection via 5 research articles and 6 review articles. The different reviews allow us to take stock of cell death, oxidative stress and neuroinflammation in the context of neurodegenerative diseases but also in relation to other pathologies where these processes are involved.




Oxidative Stress and Neurodegenerative Disorders


Book Description

Oxidative stress is the result of an imbalance in pro-oxidant/antioxidant homeostasis that leads to the generation of toxic reactive oxygen species. Brain cells are continuously exposed to reactive oxygen species generated by oxidative metabolism, and in certain pathological conditions defense mechanisms against oxygen radicals may be weakened and/or overwhelmed. DNA is a potential target for oxidative damage, and genomic damage can contribute to neuropathogenesis. It is important therefore to identify tools for the quantitative analysis of DNA damage in models on neurological disorders. This book presents detailed information on various neurodegenerative disorders and their connection with oxidative stress. This information will provide clinicians with directions to treat these disorders with appropriate therapy and is also of vital importance for the drug industries for the design of new drugs for treatment of degenerative disorders.* Contains the latest information on the subject of neurodegenerative disorders* Reflects on various factors involved in degeneration and gives suggestions for how to tackle these problems




Inflammation and Oxidative Stress in Neurological Disorders


Book Description

Unless new discoveries are made in the prevention or treatment of stroke, Alzheimer's Disease and depression, the number of patients with these diseases is sure to increase dramatically by the year 2050. Thus, developing strategies to retard or delay the onset of stroke, AD and depression these neurological disorders is of critical important. The present monograph will provide current and comprehensive information on the relationship between neuroinflammation and oxidative stress in age-related neurological disorders at the molecular level. The information described in this monograph on lifestyle (diet and exercise), genes and age is intended to facilitate and promote new discoveries for the treatment of age-related neurological disorders.




Brain Aging


Book Description

Recognition that aging is not the accumulation of disease, but rather comprises fundamental biological processes that are amenable to experimental study, is the basis for the recent growth of experimental biogerontology. As increasingly sophisticated studies provide greater understanding of what occurs in the aging brain and how these changes occur




Magnesium in the Central Nervous System


Book Description

The brain is the most complex organ in our body. Indeed, it is perhaps the most complex structure we have ever encountered in nature. Both structurally and functionally, there are many peculiarities that differentiate the brain from all other organs. The brain is our connection to the world around us and by governing nervous system and higher function, any disturbance induces severe neurological and psychiatric disorders that can have a devastating effect on quality of life. Our understanding of the physiology and biochemistry of the brain has improved dramatically in the last two decades. In particular, the critical role of cations, including magnesium, has become evident, even if incompletely understood at a mechanistic level. The exact role and regulation of magnesium, in particular, remains elusive, largely because intracellular levels are so difficult to routinely quantify. Nonetheless, the importance of magnesium to normal central nervous system activity is self-evident given the complicated homeostatic mechanisms that maintain the concentration of this cation within strict limits essential for normal physiology and metabolism. There is also considerable accumulating evidence to suggest alterations to some brain functions in both normal and pathological conditions may be linked to alterations in local magnesium concentration. This book, containing chapters written by some of the foremost experts in the field of magnesium research, brings together the latest in experimental and clinical magnesium research as it relates to the central nervous system. It offers a complete and updated view of magnesiums involvement in central nervous system function and in so doing, brings together two main pillars of contemporary neuroscience research, namely providing an explanation for the molecular mechanisms involved in brain function, and emphasizing the connections between the molecular changes and behavior. It is the untiring efforts of those magnesium researchers who have dedicated their lives to unraveling the mysteries of magnesiums role in biological systems that has inspired the collation of this volume of work.




The Aging Mind


Book Description

Possible new breakthroughs in understanding the aging mind that can be used to benefit older people are now emerging from research. This volume identifies the key scientific advances and the opportunities they bring. For example, science has learned that among older adults who do not suffer from Alzheimer's disease or other dementias, cognitive decline may depend less on loss of brain cells than on changes in the health of neurons and neural networks. Research on the processes that maintain neural health shows promise of revealing new ways to promote cognitive functioning in older people. Research is also showing how cognitive functioning depends on the conjunction of biology and culture. The ways older people adapt to changes in their nervous systems, and perhaps the changes themselves, are shaped by past life experiences, present living situations, changing motives, cultural expectations, and emerging technology, as well as by their physical health status and sensory-motor capabilities. Improved understanding of how physical and contextual factors interact can help explain why some cognitive functions are impaired in aging while others are spared and why cognitive capability is impaired in some older adults and spared in others. On the basis of these exciting findings, the report makes specific recommends that the U.S. government support three major new initiatives as the next steps for research.




Alzheimer's Disease: Cellular and Molecular Aspects of Amyloid beta


Book Description

To understand Alzheimer's disease (AD) is one of the major thrusts of present-day clinical research, strongly supported by more fimdamental cellular, biochemical, immunological and structural studies. It is these latter that receive attention within this book. This compilation of 20 chapters indicates the diversity of work currently in progress and summarizes the current state of knowledge. Experienced authors who are scientifically active in their fields of study have been selected as contributors to this book, in an attempt to present a reasonably complete survey of the field. Inevitably, some exciting topics for one reason or another have not been included, for which we can only apologize. Standardization of terminology is often a problem in science, not least in the Alzheimer field; editorial effort has been made to achieve standardization between the Chapters, but some minor yet acceptable personal / author variation is still present, i. e. P-amyloid/amyloid-P; Ap42/Apl-42/APi. 42! The book commences with a broad survey of the contribution that the range of available microscopical techniques has made to the study of Alzheimer's amyloid plaques and amyloid fibrillogenesis. This chapter also serves as an Introduction to the book, since several of the topics introduced here are expanded upon in later chapters. Also, it is significant to the presence of this chapter that the initial discovery of brain plaques, by Alois Alzheimer, utilized light microscopy, a technique that continues to be extremely valuable in present-day AD research.




Neurodegenerative Diseases


Book Description

The editor of this volume, having research interests in the field of ROS production and the damage to cellular systems, has identified a number of enzymes showing ·OH scavenging activities details of which are anticipated to be published in the near future as confirmatory experiments are awaited. It is hoped that the information presented in this book on NDs will stimulate both expert and novice researchers in the field with excellent overviews of the current status of research and pointers to future research goals. Clinicians, nurses as well as families and caregivers should also benefit from the material presented in handling and treating their specialised cases. Also the insights gained should be valuable for further understanding of the diseases at molecular levels and should lead to development of new biomarkers, novel diagnostic tools and more effective therapeutic drugs to treat the clinical problems raised by these devastating diseases.




Neuronal Cell Death


Book Description

This volume represents a valuable and readily reproducible collection of established and emerging techniques for neuronal cell death research. Conveniently divided into four parts, sections cover a series of techniques for the molecular, structural, functional and genomic characterization of dying neurons, a number of protocols that are of primary interest in neuropathology and in experimental neuropathology, a series of gene engineering techniques to obtain and manipulate neuronal stem cells and progenitors, to prepare HSV-1 vectors for the gene therapy, and to CNS transplantation of bone marrow stem cells, and finally, some very interesting protocols for the study of cell death in non-mammalian models. Written in the successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and easily accessible, Neuronal Cell Death: Methods and Protocols seeks to serve a large audience of scientists that are currently active in the field or are willing to enter such an exciting and still expanding area of neurobiology.




The Propagation of Neurodegenerative Diseases by Inflammation and Exosomes


Book Description

Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the two most common neurodegenerative diseases with rates increasing along with the ageing global population. Despite best efforts, we still do not understand the etiopathogenesis of these diseases and there are no effective disease-modifying treatments. Cognitive deficiencies or motor complications that emerge during AD and PD are thought to be the result of the accumulation of misfolded, aggregate-prone proteins, such as amyloid-? (A?) and tau or ?-synuclein (?-syn), respectively. Growing evidence suggests that prefibrillar oligomers of A? and ?-syn (oA? and o?-syn) are key contributors to the progression of these diseases. The progressive accumulation of these proteins leads to a gradual spread of pathology throughout interconnected brain regions, but the mechanisms by which this spreading occurs are still largely unknown. Neuroinflammation has been recognised as an important contributor to neurodegenerative disease. It is hypothesised that a pro-inflammatory environment initiated by the innate immune system, either through activation from A? itself or indirectly through neuronal injury signals in AD. These phenomena are thought to either cause or accelerate AD, such that an anti-inflammatory approach may be neuroprotective. In paper I, we investigated whether different inflammatory environments affected the transfer of oA? between neuron-like cells, in addition to investigating inter- and intracellular protein changes. This study demonstrated that an anti-inflammatory environment reduces the transfer of oA? between cells. We also provide evidence that these cells begin to take on the “phenotype” of the inflammatory milieu, while also demonstrating that the expression profile of endosomal/lysosomal and protein trafficking proteins is altered during these conditions. Small extracellular vesicles called exosomes, which are key players in cell to cell communication, have been proposed to play an influential role in spreading neurodegenerative proteins between cells. Exosomes are small membranous vesicles that are formed by the inward budding of multivesicular bodies (MVBs). These MVBs can then merge with the plasma membrane to be released into the extracellular environment as vesicles, which serve as vehicles for transferring proteins, lipids, and mRNAs between cells. The ESCRT-dependent pathway is the most understood mechanism underlying exosome biogenesis. However, exosomes can also be formed through ESCRT-independent pathways, including through the hydrolysis of sphingomyelin by neutral sphingomyelinase 2 (nSMase2), which produces ceramide. Paper II investigated whether exosomes formed through an ESCRT-independent pathway plays a significant role in the transfer of o?-syn between neuron-like cells. As oxidative stress is a common feature in PD brains, which in turn dysregulates nSMase2 activity, we also tested our model under hypoxic conditions. Inhibition of nSMase2 significantly reduced the transfer of o?-syn between cells but also resulted in decreased ?-syn aggregation. Hypoxia did not influence o?-syn transfer, however, it significantly dysregulated the sphingolipid composition, which may be important for ?-syn binding to exosomes and exosome communication. During AD and PD, there is a noted reduction in the effectiveness of autophagy, a process critical to cellular proteostasis. Recent studies have uncovered shared regulatory mechanisms of exosome biogenesis and autophagy, suggesting that they are closely linked. Previous findings have shown that inhibition of autophagy in AD mice mediates A? trafficking through altering the secretion of A? in MVBs. To further study this effect, we investigated the interplay between autophagy and exosome secretion using ATG7 knock-out x APPNL-F knock-in AD mice in paper III. These autophagy-deficient AD mice had a reduced extracellular A? plaque load, but increased intracellular A?, which was found to be assembled into higher-ordered assemblies. While exosomal secretion was dysregulated in these mice, the amount of A? packaged into the exosomes was unchanged. Lastly, one of the biggest challenges in developing effective treatments for AD is the lack of early diagnosis of living patients. As the connection between exosomes and the spread of neurodegenerative proteins is still relatively new, there remains a diagnostic potential to be explored with exosomes. Paper IV aimed to develop a new diagnostic assay to detect oA? in exosomes isolated from human cerebrospinal fluid. Although exosomal oA? was readily detected in some of these samples, the assay’s sensitivity requires additional optimisation before it can be further validated for the clinic. In summary, the studies presented in this thesis have furthered our understanding of how inflammation, autophagy, and exosomes contribute to the intercellular transmission of AD and PD associated proteins. We have shown that an anti-inflammatory approach may slow down the progression of AD through reducing the transfer of oA? between cells. We also provide novel findings relating to the biogenesis of exosomes, which in turn affected the ability of exosomes to transmit neurodegenerative proteins between cells, and their association with autophagic processes. Finally, we have investigated the feasibility of exosomes as an early AD diagnostic marker. This work has helped to elucidate some of the mechanisms underlying the progression of neurodegenerative diseases, which may be useful targets for the investigation of new therapeutic avenues.