Implications of Sodium Proton Exchanger Nhe1 knockdown in the Drosophila melanogaster neuromuscular junction
Abstract / Artist's Statement
Regulation of pH is essential for every living cell. While pH is implicated in brain development, the exact mechanisms behind its effects on signaling pathways and the impacts on cell behavior are not yet fully understood. The fruit fly (Drosophila melanogaster) provides a great model organism for identifying genetic mechanisms of nervous system development, due to only having four pairs of chromosomes and well characterized patterns of neural development . Sodium (Na+) Proton (H+) Exchanger (Nhe) proteins shape the cellular environment by acting as major modifiers of Na+ ion balance and pH. The shared homology and lack of genetic redundancy in the fruit fly offers a direct approach to understanding the importance of these proton exchangers and their regulation of pH at subcellular levels. In fruit flies, there are 3 Nhe protein subtypes, with Nhe1 being most closely related to the human Nhe8 that is localized in the Golgi apparatus. Previous work in the Piggott Lab has found that Nhe2 and Nhe3 are important regulators of neuronal morphology. RNAi knockdown of Nhe2 or Nhe3 resulted in increased numbers of synaptic boutons at the neuromuscular junction (NMJ). Synaptic boutons are where neurons connect to muscle during development. Previous research has found that genetic mutants that increased activity in developing motor neurons were sufficient to increase bouton numbers. Thus, our research proposes that knockdown of Nhe proteins would effectively acidify neurons and may alter neuronal excitability leading to increased bouton numbers. Single cell sequencing data suggests Nhe1 may have similar expression to Nhe2 and Nhe3, so my experiments will test whether RNAi knockdown of Nhe1 will act similarly to other Nhe proteins and result in an increased number of synaptic boutons. Using immunohistochemistry and confocal microscopy, I will compare motor neuron projections in the NMJ in experimental groups to control animals to determine whether neuronal morphology is affected by Nhe1 expression level. The results of these experiments will provide insight into how neuronal pH regulation shapes neurons. As Nhe disruptions in humans cause developmental diseases like Christianson syndrome, my research will provide an essential step towards understanding the role of Nhe proteins in pH regulation and how dysregulation affects disease pathology.
Implications of Sodium Proton Exchanger Nhe1 knockdown in the Drosophila melanogaster neuromuscular junction
UC South Ballroom
Regulation of pH is essential for every living cell. While pH is implicated in brain development, the exact mechanisms behind its effects on signaling pathways and the impacts on cell behavior are not yet fully understood. The fruit fly (Drosophila melanogaster) provides a great model organism for identifying genetic mechanisms of nervous system development, due to only having four pairs of chromosomes and well characterized patterns of neural development . Sodium (Na+) Proton (H+) Exchanger (Nhe) proteins shape the cellular environment by acting as major modifiers of Na+ ion balance and pH. The shared homology and lack of genetic redundancy in the fruit fly offers a direct approach to understanding the importance of these proton exchangers and their regulation of pH at subcellular levels. In fruit flies, there are 3 Nhe protein subtypes, with Nhe1 being most closely related to the human Nhe8 that is localized in the Golgi apparatus. Previous work in the Piggott Lab has found that Nhe2 and Nhe3 are important regulators of neuronal morphology. RNAi knockdown of Nhe2 or Nhe3 resulted in increased numbers of synaptic boutons at the neuromuscular junction (NMJ). Synaptic boutons are where neurons connect to muscle during development. Previous research has found that genetic mutants that increased activity in developing motor neurons were sufficient to increase bouton numbers. Thus, our research proposes that knockdown of Nhe proteins would effectively acidify neurons and may alter neuronal excitability leading to increased bouton numbers. Single cell sequencing data suggests Nhe1 may have similar expression to Nhe2 and Nhe3, so my experiments will test whether RNAi knockdown of Nhe1 will act similarly to other Nhe proteins and result in an increased number of synaptic boutons. Using immunohistochemistry and confocal microscopy, I will compare motor neuron projections in the NMJ in experimental groups to control animals to determine whether neuronal morphology is affected by Nhe1 expression level. The results of these experiments will provide insight into how neuronal pH regulation shapes neurons. As Nhe disruptions in humans cause developmental diseases like Christianson syndrome, my research will provide an essential step towards understanding the role of Nhe proteins in pH regulation and how dysregulation affects disease pathology.