Effects of the Unfolded Protein Response and ER Stress on Neuronal Development in Zebrafish
Faculty Mentor Name
Lisa Wrischnik and Doug Weiser
Research or Creativity Area
Natural Sciences
Abstract
In cells, the accumulation of misfolded or unfolded proteins activates the unfolded protein response (UPR), a stress pathway triggered by conditions such as heat shock or nutrient imbalance. UPR activation is implicated in human diseases, including several neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. Although the UPR protects cells by preventing excessive buildup of unfolded proteins in the endoplasmic reticulum, prolonged activation can trigger apoptosis, leading to neuronal loss. Because ER stress can induce cell death, it is considered a potential driver of neurodegeneration.
The timing of translation re-initiation is critical, as restarting too early can lead to apoptosis and waiting too long prevents the production of essential proteins. The proteins GADD34 and CReP are central to restarting translation. Studies show that inhibiting this process can protect neurons after stroke and prevent degeneration in models of Parkinson’s Disease and Charcot-Marie-Tooth disease, showing this pathway plays important roles in both the central and peripheral nervous systems.
The goal of this project is to use zebrafish to examine how mutations in GADD34 and CReP affect neuronal development or survival. Zebrafish embryos are ideal because they are transparent and share similarities with humans. We chose in situ hybridization to visualize the nervous system and detect changes in neuronal gene expression. Three zebrafish genes were cloned to target three different types of neurons: elavl3 (pan-neuronal), isl1 (peripheral nervous system), and neuroD (developing neurons).
We will be presenting results on an analysis of wild-type versus the GADD34(-/-);CReP (-/-) double knockout mutants for changes in elavl3 and isl1 expression patterns. In addition we will be presenting results on control embryos versus embryos exposed to stress-inducing drugs for six hours, to assess how ER stress influences early neuronal development.
Effects of the Unfolded Protein Response and ER Stress on Neuronal Development in Zebrafish
In cells, the accumulation of misfolded or unfolded proteins activates the unfolded protein response (UPR), a stress pathway triggered by conditions such as heat shock or nutrient imbalance. UPR activation is implicated in human diseases, including several neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. Although the UPR protects cells by preventing excessive buildup of unfolded proteins in the endoplasmic reticulum, prolonged activation can trigger apoptosis, leading to neuronal loss. Because ER stress can induce cell death, it is considered a potential driver of neurodegeneration.
The timing of translation re-initiation is critical, as restarting too early can lead to apoptosis and waiting too long prevents the production of essential proteins. The proteins GADD34 and CReP are central to restarting translation. Studies show that inhibiting this process can protect neurons after stroke and prevent degeneration in models of Parkinson’s Disease and Charcot-Marie-Tooth disease, showing this pathway plays important roles in both the central and peripheral nervous systems.
The goal of this project is to use zebrafish to examine how mutations in GADD34 and CReP affect neuronal development or survival. Zebrafish embryos are ideal because they are transparent and share similarities with humans. We chose in situ hybridization to visualize the nervous system and detect changes in neuronal gene expression. Three zebrafish genes were cloned to target three different types of neurons: elavl3 (pan-neuronal), isl1 (peripheral nervous system), and neuroD (developing neurons).
We will be presenting results on an analysis of wild-type versus the GADD34(-/-);CReP (-/-) double knockout mutants for changes in elavl3 and isl1 expression patterns. In addition we will be presenting results on control embryos versus embryos exposed to stress-inducing drugs for six hours, to assess how ER stress influences early neuronal development.
