The tau proteins are a group of six highly soluble protein isoforms produced by alternative splicing from the gene MAPT. They have roles primarily in maintaining the stability of microtubules in axons and are abundant in the neurons of the central nervous system (CNS), where the cerebral cortex has the highest abundance. They are less common elsewhere but are also expressed at very low levels in CNS astrocytes and oligodendrocytes.
Frontotemporal lobar degeneration (FTLD) is a pathological process that occurs in frontotemporal dementia. It is characterized by atrophy in the frontal lobe and temporal lobe of the brain, with sparing of the parietal and occipital lobes.
Semantic dementia (SD), also known as semantic variant primary progressive aphasia (svPPA), is a progressive neurodegenerative disorder characterized by loss of semantic memory in both the verbal and non-verbal domains. However, the most common presenting symptoms are in the verbal domain. Semantic dementia is a disorder of semantic memory that causes patients to lose the ability to match words or images to their meanings. However, it is fairly rare for patients with semantic dementia to develop category specific impairments, though there have been documented cases of it occurring. Typically, a more generalized semantic impairment results from dimmed semantic representations in the brain.
Neurofibrillary tangles (NFTs) are aggregates of hyperphosphorylated tau protein that are most commonly known as a primary biomarker of Alzheimer's disease. Their presence is also found in numerous other diseases known as tauopathies. Little is known about their exact relationship to the different pathologies.
Tauopathy belongs to a class of neurodegenerative diseases involving the aggregation of tau protein into neurofibrillary or gliofibrillary tangles in the human brain. Tangles are formed by hyperphosphorylation of the microtubule protein known as tau, causing the protein to dissociate from microtubules and form insoluble aggregates. The mechanism of tangle formation is not well understood, and whether tangles are a primary cause of Alzheimer's disease or play a peripheral role is unknown.
Apolipoprotein E (Apo-E) is a protein involved in the metabolism of fats in the body of mammals. A subtype is implicated in the Alzheimer's disease and cardiovascular diseases. It is encoded in humans by the gene APOE.
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, 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.
Granulin is a protein that in humans is encoded by the GRN gene. Each granulin protein is cleaved from the precursor progranulin, a 593 amino-acid-long and 68.5 kDa protein. While the function of progranulin and granulin have yet to be determined, both forms of the protein have been implicated in development, inflammation, cell proliferation and protein homeostasis. The 2006 discovery of the GRN mutation in a population of patients with frontotemporal dementia has spurred much research in uncovering the function and involvement in disease of progranulin in the body. While there is a growing body of research on progranulin's role in the body, studies on specific granulin residues are still limited.
Peroxiredoxin-2 is a protein that in humans is encoded by the PRDX2 gene.
Kallikrein-10 is a protein that in humans is encoded by the KLK10 gene.
TAR DNA-binding protein 43 is a protein that in humans is encoded by the TARDBP gene.
Fibroblast growth factor 14 is a biologically active protein that in humans is encoded by the FGF14 gene.
Transmembrane protein 106B is a protein that is encoded by the TMEM106B gene. It is found primarily within neurons and oligodendrocytes in the central nervous system with its subcellular location being in lysosomal membranes. TMEM106B helps facilitate important functions for maintaining a healthy lysosome, and therefore certain mutations and polymorphisms can lead to issues with proper lysosomal function. Lysosomes are in charge of clearing out mis-folded proteins and other debris, and thus, play an important role in neurodegenerative diseases that are driven by the accumulation of various mis-folded proteins and aggregates. Due to its impact on lysosomal function, TMEM106B has been investigated and found to be associated to multiple neurodegenerative diseases.
Tryptophan hydroxylase 1 (TPH1) is an isoenzyme of tryptophan hydroxylase which in humans is encoded by the TPH1 gene.
Neurofilament light polypeptide, also known as neurofilament light chain, is a neurofilament protein that in humans is encoded by the NEFL gene. Neurofilament light chain is a biomarker that can be measured with immunoassays in cerebrospinal fluid and plasma and reflects axonal damage in a wide variety of neurological disorders. It is a useful marker for disease monitoring in amyotrophic lateral sclerosis, multiple sclerosis, Alzheimer's disease, and more recently Huntington's disease. It is also promising marker for follow-up of patients with brain tumors. Higher numbers have been associated with increased mortality.
Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems with language, disorientation, mood swings, loss of motivation, self-neglect, and behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years.
Virginia Man-Yee Lee is a Chinese-born American biochemist and neuroscientist who specializes in the research of Alzheimer's disease. She is the current John H. Ware 3rd Endowed Professor in Alzheimer's Research at the Department of Pathology and Laboratory Medicine, and the director of the Center for Neurodegenerative Disease Research and co-director of the Marian S. Ware Alzheimer Drug Discovery Program at the Perelman School of Medicine, University of Pennsylvania. She received the 2020 Breakthrough Prize in Life Sciences.
Rahul Desikan was an Indian-American neuroscientist and neuroradiologist. He was an Assistant Professor of Radiology & Biomedical Imaging, Neurology and Pediatrics at the University of California, San Francisco, and co-director of Laboratory for Precision Neuroimaging. Desikan's achievements became publicly known in a Washington Post article detailing his lifelong commitment to preventing and treating Alzheimer's disease and his continuing work as a scientist living with Amyotrophic lateral sclerosis (ALS). Desikan was vocal about the need for increased awareness and research funding for ALS, and voiced his unique perspective as both ALS researcher and ALS patient in op-ed articles appearing in a regular column in the Washington Post as well as in the San Francisco Chronicle and Scientific American.
Alison Mary Goate is a professor of neuroscience and Director of the Loeb Center for Alzheimer's Disease at Icahn School of Medicine at Mount Sinai, New York City. She was previously professor of genetics in psychiatry, professor of genetics, and professor of neurology at Washington University in St. Louis.
Gerard David Schellenberg is an academic neuropathologist who specializes in the research of Alzheimer's disease. He is the director of Penn Neurodegeneration Genomics Center as well as a professor of Pathology and Laboratory Medicine at the University of Pennsylvania. He is a leading contributor to Alzheimer's disease research.
