Investigating Proteostasis Imbalances in C. elegans expressing TDP-43, an Amyotrophic Lateral Sclerosis disease associated protein
Location
Poster #4
Department
Biology
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized primarily by degeneration of motor neurons leading to muscle atrophy and paralysis. Mutations in TAR-DNA protein of 43 kDa (TDP-43) have been linked to familial cases of ALS. TDP-43 is an RNA binding protein that shuttles mRNA between the nucleus and cytosol. In ALS, TDP-43 accumulates in the cytosol of affected neurons as hyperphosphorylated and ubiquitinated aggregates. Imbalances in key proteostasis pathways, such as protein clearance, have been implicated in many neurodegenerative diseases. Proper targeting of misfolded proteins for degradation is critical for cellular health. To learn more about the connection between proteostasis imbalances and TDP-43 neurotoxicity, we are taking advantage of the nematode C. elegans simple nervous system and well characterized behavioral assays. Using a ribosome profiling dataset of C. elegans expressing TDP-43 pan-neuronally, I identified three upregulated genes, usp-33, asp-17, and T28H10.3 that are involved in protein clearance. Currently, I am conducting a genetic cross to introduce deletions of these genes into TDP-43 expressing worms. Using molecular genotyping, I will identify F3 TDP-43 expressing worms that are homozygous for the deletions. Once the new strains are generated, I will perform a thrashing assay to evaluate motor neuron defects. I expect C. elegans expressing neuronal TDP-43 with a deletion of the usp-33 gene, as well as strains with asp-17 and T28H10.3 gene deletions, will exhibit fewer body thrashes. The enhanced motor neuron deficits in TDP-43 animals along with upregulation of these genes suggests that neurons may be activating mechanisms to clear TDP-43 aggregates. In addition, I will conduct a western blot analysis to determine the level of TDP-43 in the newly generated strains. I expect C. elegans expressing neuronal TDP-43 and harboring deletions of usp-33, asp-17, and T28H10.3 genes will exhibit an altered level of TDP-43, demonstrating a role for these genes in TDP-43 clearance. Understanding the mechanisms neurons employ to clear TDP-43 aggregates may reveal therapeutic targets to alleviate ALS pathology.
Faculty Sponsor
Cindy Voisine
Investigating Proteostasis Imbalances in C. elegans expressing TDP-43, an Amyotrophic Lateral Sclerosis disease associated protein
Poster #4
Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized primarily by degeneration of motor neurons leading to muscle atrophy and paralysis. Mutations in TAR-DNA protein of 43 kDa (TDP-43) have been linked to familial cases of ALS. TDP-43 is an RNA binding protein that shuttles mRNA between the nucleus and cytosol. In ALS, TDP-43 accumulates in the cytosol of affected neurons as hyperphosphorylated and ubiquitinated aggregates. Imbalances in key proteostasis pathways, such as protein clearance, have been implicated in many neurodegenerative diseases. Proper targeting of misfolded proteins for degradation is critical for cellular health. To learn more about the connection between proteostasis imbalances and TDP-43 neurotoxicity, we are taking advantage of the nematode C. elegans simple nervous system and well characterized behavioral assays. Using a ribosome profiling dataset of C. elegans expressing TDP-43 pan-neuronally, I identified three upregulated genes, usp-33, asp-17, and T28H10.3 that are involved in protein clearance. Currently, I am conducting a genetic cross to introduce deletions of these genes into TDP-43 expressing worms. Using molecular genotyping, I will identify F3 TDP-43 expressing worms that are homozygous for the deletions. Once the new strains are generated, I will perform a thrashing assay to evaluate motor neuron defects. I expect C. elegans expressing neuronal TDP-43 with a deletion of the usp-33 gene, as well as strains with asp-17 and T28H10.3 gene deletions, will exhibit fewer body thrashes. The enhanced motor neuron deficits in TDP-43 animals along with upregulation of these genes suggests that neurons may be activating mechanisms to clear TDP-43 aggregates. In addition, I will conduct a western blot analysis to determine the level of TDP-43 in the newly generated strains. I expect C. elegans expressing neuronal TDP-43 and harboring deletions of usp-33, asp-17, and T28H10.3 genes will exhibit an altered level of TDP-43, demonstrating a role for these genes in TDP-43 clearance. Understanding the mechanisms neurons employ to clear TDP-43 aggregates may reveal therapeutic targets to alleviate ALS pathology.