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Description
Alzheimer’s Disease (AD) and Frontotemporal Dementia (FTD) are the leading causes of early onset dementia. There are currently no ways to slow down progression, to prevent or cure AD and FTD. Both AD and FTD share a lot of the symptoms and pathology. Initial symptoms such as confusion, memory loss,

Alzheimer’s Disease (AD) and Frontotemporal Dementia (FTD) are the leading causes of early onset dementia. There are currently no ways to slow down progression, to prevent or cure AD and FTD. Both AD and FTD share a lot of the symptoms and pathology. Initial symptoms such as confusion, memory loss, mood swings and behavioral changes are common in both these dementia subtypes. Neurofibrillary tau tangles and intraneuronal aggregates of TAR DNA Binding Protein 43 (TDP-43) are also observed in both AD and FTD. Hence, FTD cases are often misdiagnosed as AD due to a lack of accurate diagnostics. Prior to the formation of tau tangles and TDP-43 aggregates, tau and TDP-43 exist as intermediate protein variants which correlate with cognitive decline and progression of these neurodegenerative diseases. Effective diagnostic and therapeutic agents would selectively recognize these toxic, disease-specific variants. Antibodies or antibody fragments such as single chain antibody variable domain fragments (scFvs), with their diverse binding capabilities, can aid in developing reagents that can selectively bind these protein variants. A combination of phage display library and Atomic Force Microscopy (AFM)-based panning was employed to identify antibody fragments against immunoprecipitated tau and immunoprecipitated TDP-43 from human postmortem AD and FTD brain tissue respectively. Five anti-TDP scFvs and five anti-tau scFvs were selected for characterization by Enzyme Linked Immunosorbent Assays (ELISAs) and Immunohistochemistry (IHC). The panel of scFvs, together, were able to identify distinct protein variants present in AD but not in FTD, and vice versa. Generating protein variant profiles for individuals, using the panel of scFvs, aids in developing targeted diagnostic and therapeutic plans, gearing towards personalized medicine.
ContributorsVenkataraman, Lalitha (Author) / Sierks, Michael R (Thesis advisor) / Dunckley, Travis (Committee member) / Oddo, Salvatore (Committee member) / Stabenfeldt, Sarah (Committee member) / Arizona State University (Publisher)
Created2018
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Description
Traumatic Brain Injury (TBI) affects approximately two million people on an annual basis and increases the frequency and onset of Alzheimer’s disease (AD) and other related dementias (ADRDs). Mechanical damage and shearing of neuronal axons are thought to be responsible for producing toxic variants of proteins that contribute to disease

Traumatic Brain Injury (TBI) affects approximately two million people on an annual basis and increases the frequency and onset of Alzheimer’s disease (AD) and other related dementias (ADRDs). Mechanical damage and shearing of neuronal axons are thought to be responsible for producing toxic variants of proteins that contribute to disease pathology. Specifically, the tau, beta amyloid, alpha-synuclein, and TAR-binding DNA Protein-43 (TDP-43) variants contribute to the heterogenous pathology mechanisms of neurodegenerative diseases. The Sierks lab at Arizona State University has aimed to study how these protein variants collectively interact to contribute to pathologies characteristic of AD/ADRDs. This study focuses on the accumulation of toxic oligomeric variants of TDP-43 secondary to TBI. The first aim of this study was to identify the protein variant fingerprint as a function time following experimental diffuse TBI. The second aim was to investigate if toxic variants of TDP-43 were associated with cognitive and motor functional deficits. C57BL/6 mice were subjected to a single or repetitive diffuse TBI via midline fluid percussion injury or a control surgery (sham). Post-injury, mice were evaluated for cognitive performance, sensorimotor function, and depressive-like behavior at 7-, 14-, and 28-days post-injury. Tissue was collected for immunohistochemistry and stained for ADTDP-3, a single chain antibody variable fragment (ScFv) which binds to toxic variants of TDP-43 in amyotrophic lateral sclerosis (ALS) and AD tissue. A one-way analysis of variance (ANOVA) was performed to compare staining intensity across various brain regions. Subsequently, a Pearson correlation was performed to compare behavioral task performance to staining intensity by brain region for each injury group. There were significantly elevated levels of ADTDP3 binding in all regions except for the hippocampus, and there was a significant correlation between the cortex staining intensity vs the cognitive behavior test at 7 days post-injury. There was also a significant correlation between the thalamus staining intensity and sensorimotor test at 7 days post-injury. These findings support the hypothesis that the accumulation of toxic variants of TDP-43 can contribute to neurodegenerative pathology and loss of function. These variants also may contribute to behavioral deficits secondary to diffuse TBI.
ContributorsAftab, Umar Syed (Author) / Sierks, Michael R (Thesis advisor) / Rowe, Rachel K (Thesis advisor) / Newbern, Jason M (Committee member) / Arizona State University (Publisher)
Created2021
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Description

Traumatic brain injury (TBI) is defined as an injury to the head that disrupts normal brain function. TBI has been described as a disease process that can lead to an increased risk for developing chronic neurodegenerative diseases, like frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). A pathological hallmark

Traumatic brain injury (TBI) is defined as an injury to the head that disrupts normal brain function. TBI has been described as a disease process that can lead to an increased risk for developing chronic neurodegenerative diseases, like frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). A pathological hallmark of FTLD and a hallmark of ALS is the nuclear mislocalization of TAR DNA Binding Protein 43 (TDP-43). This project aims to explore neurodegenerative effects of TBI on cortical lesion area using immunohistochemical markers of TDP-43 proteinopathies. We analyzed the total percent of NEUN positive cells displaying TDP-43 nuclear mislocalization. We found that the percent of NEUN positive cells displaying TDP-43 nuclear mislocalization was significantly higher in cortical tissue following TBI when compared to the age-matched control brains. The cortical lesion area was analyzed for each injured brain sample, with respect to days post-injury (DPI), and it was found that there were no statistically significant differences between cortical lesion areas across time points. The percent of NEUN positive cells displaying TDP-43 nuclear mislocalization was analyzed for each cortical tissue sample, with respect to cortical lesion area, and it was found that there were no statistically significant differences between the percent of NEUN positive cells displaying TDP-43 nuclear mislocalization, with respect to cortical lesion area. In conclusion, we found no correlation between the percent of cortical NEUN positive cells displaying TDP-43 nuclear mislocalization with respect to the size of the cortical lesion area.

ContributorsWong, Jennifer (Author) / Stabenfeldt, Sarah (Thesis director) / Bjorklund, Reed (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2022-05