2024-04-162024-04-162024-03-21https://hdl.handle.net/20.500.12503/32573Purpose: Identify neuroprotective compounds that could potentially be used for conditions like Alzheimer’s disease. Sigma 1 receptors are an intracellular chaperone protein involved in endoplasmic reticulum stress response. Ligands of sigma 1 receptor have been shown to be acutely neuroprotective in a number of in vitro and in vivo brain injury models including stroke and traumatic brain injury. We are examining potential for novel sigma 1 compounds to protect the mouse hippocampal cell line HT22 from oxidative stress and endoplasmic reticulum stress. Among the compounds tested are haloperidol, cutamesine, oxeladin which are neuroprotective in stroke, and additional proprietary ligands derived from substituted haloperidol. Methods: Cell death in HT22 cells was determined using Cell Counting Kit 8. Cells were plated in quadruplicate in 96 well plates for 24 hours in DMEM/10%FBS. Cells were then treated with either hydrogen peroxide (H2O2, 0.5 mM) or Tunicamycin (50 ng/mL) for 24 hours with or without sigma 1 ligands (100 nM). Results: Haloperidol, a mixed sigma 1 and dopamine agonist, dose dependently protected cells from both H2O2 and Tunicamycin induced cell death. However, the sedative actions of Haloperidol make it unsuitable for use against neuroprotective diseases in vivo. We tested 3 sigma 1 compounds without dopamine activity to determine whether sigma 1 activity would protect cells against these insults. Preliminary results suggests that all sigma 1 compounds tested show some efficacy against oxidative stress and ER stress dependent cell death. Average percent live cells after treatment with 0.5 mM hydrogen peroxide was 59.55% (n = 3) and average percent live cells after treatment with 0.5 mM hydrogen peroxide and 100 nM Haloperidol was 101.06% (n = 5). Average percent live cells after treatment with 50 ng/mL Tunicamycin and 100 nM Haloperidol was 85.8% (n = 2). Average percent live cells after treatment with 50 ng/mL Tunicamycin and 100 nM Oxeladin was 49.7% (n = 2). Average percent live cells after treatment with 50 ng/mL Tunicamycin and 100 nM Cutamesine was 74.4% (n = 2). Average percent live cells after treatment with 50 ng/mL Tunicamycin and 100 nM of a novel sigma 1 agonist was 85.7% (n = 2). Ongoing studies are examining the intracellular pathways responsible for neuroprotective effects. Conclusion: Novel sigma 1 agonists may be suitable for protecting neurons against neurodegenerative diseases like Alzheimer’s. In terms of examining mechanisms, we are exploring endoplasmic reticulum stress pathways and more traditional apoptotic signaling.enposter