The neuroimmune system is a system of structures and processes involving the biochemical and electrophysiological interactions between the nervous system and immune system which protect neurons from pathogens. It serves to protect neurons against disease by maintaining selectively permeable barriers, mediating neuroinflammation and wound healing in damaged neurons, and mobilizing host defenses against pathogens.
A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease, Alzheimer's disease, Huntington's disease, multiple system atrophy, tauopathies, and prion diseases. Neurodegeneration can be found in the brain at many different levels of neuronal circuitry, ranging from molecular to systemic. Because there is no known way to reverse the progressive degeneration of neurons, these diseases are considered to be incurable; however research has shown that the two major contributing factors to neurodegeneration are oxidative stress and inflammation. Biomedical research has revealed many similarities between these diseases at the subcellular level, including atypical protein assemblies and induced cell death. These similarities suggest that therapeutic advances against one neurodegenerative disease might ameliorate other diseases as well.
The AP2 adaptor complex is a multimeric protein that works on the cell membrane to internalize cargo in clathrin-mediated endocytosis. It is a stable complex of four adaptins which give rise to a structure that has a core domain and two appendage domains attached to the core domain by polypeptide linkers. These appendage domains are sometimes called 'ears'. The core domain binds to the membrane and to cargo destined for internalisation. The alpha and beta appendage domains bind to accessory proteins and to clathrin. Their interactions allow the temporal and spatial regulation of the assembly of clathrin-coated vesicles and their endocytosis.
The biochemistry of Alzheimer's disease, the most common cause of dementia, is not yet very well understood. Alzheimer's disease (AD) has been identified as a proteopathy: a protein misfolding disease due to the accumulation of abnormally folded amyloid beta (Aβ) protein in the brain. Amyloid beta is a short peptide that is an abnormal proteolytic byproduct of the transmembrane protein amyloid-beta precursor protein (APP), whose function is unclear but thought to be involved in neuronal development. The presenilins are components of proteolytic complex involved in APP processing and degradation.
p38 mitogen-activated protein kinases are a class of mitogen-activated protein kinases (MAPKs) that are responsive to stress stimuli, such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock, and are involved in cell differentiation, apoptosis and autophagy. Persistent activation of the p38 MAPK pathway in muscle satellite cells due to ageing, impairs muscle regeneration.
Autophagin-1 (Atg4/Apg4) is a unique cysteine protease responsible for the cleavage of the carboxyl terminus of Atg8/Apg8/Aut7, a reaction essential for its lipidation during autophagy. Human Atg4 homologues cleave the carboxyl termini of the three human Atg8 homologues, microtubule-associated protein light chain 3 (LC3), GABARAP, and GATE-16.
Low density lipoprotein receptor-related protein 1 (LRP1), also known as alpha-2-macroglobulin receptor (A2MR), apolipoprotein E receptor (APOER) or cluster of differentiation 91 (CD91), is a protein forming a receptor found in the plasma membrane of cells involved in receptor-mediated endocytosis. In humans, the LRP1 protein is encoded by the LRP1 gene. LRP1 is also a key signalling protein and, thus, involved in various biological processes, such as lipoprotein metabolism and cell motility, and diseases, such as neurodegenerative diseases, atherosclerosis, and cancer.
Hydroxycarboxylic acid receptor 2 (HCA2), also known as GPR109A and niacin receptor 1 (NIACR1), is a protein which in humans is encoded (its formation is directed) by the HCAR2 gene and in rodents by the Hcar2 gene. The human HCAR2 gene is located on the long (i.e., "q") arm of chromosome 12 at position 24.31 (notated as 12q24.31). Like the two other hydroxycarboxylic acid receptors, HCA1 and HCA3, HCA2 is a G protein-coupled receptor (GPCR) located on the surface membrane of cells. HCA2 binds and thereby is activated by D-β-hydroxybutyric acid (hereafter termed β-hydroxybutyric acid), butyric acid, and niacin (also known as nicotinic acid). β-Hydroxybutyric and butyric acids are regarded as the endogenous agents that activate HCA2. Under normal conditions, niacin's blood levels are too low to do so: it is given as a drug in high doses in order to reach levels that activate HCA2.
Triggering receptor expressed on myeloid cells 2(TREM2) is a protein that in humans is encoded by the TREM2 gene. TREM2 is expressed on macrophages, immature monocyte-derived dendritic cells, osteoclasts, and microglia, which are immune cells in the central nervous system. In the liver, TREM2 is expressed by several cell types, including macrophages, that respond to injury. In the intestine, TREM2 is expressed by myeloid-derived dendritic cells and macrophage. TREM2 is overexpressed in many tumor types and has anti-inflammatory activities. It might therefore be a good therapeutic target.
Early-onset Alzheimer's disease (EOAD), also called younger-onset Alzheimer's disease (YOAD), is Alzheimer's disease diagnosed before the age of 65. It is an uncommon form of Alzheimer's, accounting for only 5–10% of all Alzheimer's cases. About 60% have a positive family history of Alzheimer's and 13% of them are inherited in an autosomal dominant manner. Most cases of early-onset Alzheimer's share the same traits as the "late-onset" form and are not caused by known genetic mutations. Little is understood about how it starts.
Hirano bodies are intracellular aggregates of actin and actin-associated proteins first observed in neurons by Asao Hirano in 1965. The eponym ‘Hirano bodies’ was not introduced until 1968, by Schochet et al., three years after Hirano first observed the proteins.
Samuel E. Gandy, is a neurologist, cell biologist, Alzheimer's disease (AD) researcher and expert in the metabolism of the sticky substance called amyloid that clogs the brain in patients with Alzheimer's. His team discovered the first drugs that could lower the formation of amyloid.
Rudolph Emile 'Rudy' Tanzi a professor of Neurology at Harvard University, vice-chair of neurology, director of the Genetics and Aging Research Unit, and co-director of the Henry and Allison McCance Center for Brain Health at Massachusetts General Hospital (MGH).
Microglia are the primary immune cells of the central nervous system, similar to peripheral macrophages. They respond to pathogens and injury by changing morphology and migrating to the site of infection/injury, where they destroy pathogens and remove damaged cells.
Urtė Neniškytė is a Lithuanian neuroscientist. Her scientific interest and main area of work relates to the interaction of neurons and immune cells in the brain. She has studied the cellular mechanisms of Alzheimer's disease and is the co-author of the first articles about cell death in relation to phagocytosis.
Phenserine is a synthetic drug which has been investigated as a medication to treat Alzheimer's disease (AD), as the drug exhibits neuroprotective and neurotrophic effects.
Katerina Akassoglou is a neuroimmunologist who is a Senior Investigator and Director of In Vivo Imaging Research at the Gladstone Institutes. Akassoglou holds faculty positions as a Professor of Neurology at the University of California, San Francisco. Akassoglou has pioneered investigations of blood-brain barrier integrity and development of neurological diseases. She found that compromised blood-brain barrier integrity leads to fibrinogen leakage into the brain inducing neurodegeneration. Akassoglou is internationally recognized for her scientific discoveries.
Experimental models of Alzheimer's disease are organism or cellular models used in research to investigate biological questions about Alzheimer's disease as well as develop and test novel therapeutic treatments. Alzheimer's disease is a progressive neurodegenerative disorder associated with aging, which occurs both sporadically or due to familial passed mutations in genes associated with Alzheimer's pathology. Common symptoms associated with Alzheimer's disease include: memory loss, confusion, and mood changes.
Rubicon is a protein that in humans is encoded by the RUBCN gene. Rubicon is one of the few known negative regulators of autophagy, a cellular process that degrades unnecessary or damaged cellular components. Rubicon is recruited to its sites of action through interaction with the small GTPase Rab7, and impairs the autophagosome-lysosome fusion step of autophagy through inhibition of PI3KC3-C2.
Alzheimer's disease (AD) is a complex neurodegenerative disease that affects millions of people across the globe. It is also a topic of interest in the East Asian population, especially as the burden of disease increases due to aging and population growth. The pathogenesis of AD between ethnic groups is different. However, prior studies in AD pathology have focused primarily on populations of European ancestry and may not give adequate insight on the genetic, clinical, and biological differences found in East Asians with AD. Gaps in knowledge regarding Alzheimer's disease in the East Asian population introduce serious barriers to screening, early prevention, diagnosis, treatment, and timely intervention.
