Dysregulation of eIF2 Alpha Pathway in Drug-Induced Dystonia (DID) and Inherited Dystonia 16 (DYT16): Testing Novel Therapeutic Interventions
Abstract
Background: Mutations in Prkra gene, which encodes for PACT protein, cause dystonia 16 (DYT16). PACT activates PKR, a protein kinase involved in endoplasmic reticulum (ER) stress response, which causes phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2 alpha). During our previous PRMRP Discovery Award, we reported that all seven DYT16 mutations cause hyperactivation of PKR and sensitize cells to ER stress-induced apoptosis. Another key finding from these studies was that luteolin, a natural flavonoid, disrupts the abnormally strong PACT-PKR interactions in DYT16 cells to restore homeostasis and protect cells. In recent years, eIF2 alpha signaling has emerged as a pathway affected in multiple forms of dystonia. Our ground-breaking results linking PERK and PKR signaling pathways via PACT have uncovered additional drug targets. Our recent results indicate that antipsychotic drugs that trigger drug-induced dystonia (DID) also cause PKR activation and eIF2 alpha phosphorylation. Topic Area: The topic area addressed by this proposed research project is dystonia. The two areas of encouragement addressed are (i) research to identify the relationship between specific molecular/genetic changes and circuitry/network alterations in dystonia – we will study the relationship between the eIF2 alpha signaling pathway alterations by DYT16 genetic mutations as well as by antipsychotic drugs; and (ii) research on interventions to prevent, slow the progression of, or treat dystonia – we will investigate the ability of luteolin to treat DYT16 as well as DID and evaluate novel inhibitors of PKR and eIF2 alpha signaling for dystonia treatment. Rationale: It has been a generally accepted view that different forms of dystonia have no shared mechanisms. Our previous PRMRP Discovery Award work has challenged this traditional view and presented a new paradigm that dysregulated eIF2 alpha signaling is present in DYT16 as well as in several other types of dystonia. Hypothesis: Our main hypothesis is that drugs targeting the PERK-PACT-PKR-eIF2 alpha pathway will be beneficial for DYT16, other types of inherited dystonia with eIF2 alpha dysregulation, and DID. Aim 1: Investigate the effect of antipsychotic drugs on the eIF2 alpha pathway. • Characterize PKR activation, eIF2 alpha dysregulation, and apoptosis caused by antipsychotic drugs. • Evaluate luteolin and eIF2 alpha pathway-specific drugs for protecting cells after exposure to antipsychotics. Aim 2: Investigate the effect of luteolin and eIF2 alpha pathway-specific drugs on cell survival in DYT16. • Investigate if luteolin protects DYT16 cells by rescuing the dysregulated eIF2 alpha pathway. • Investigate if eIF2 alpha pathway-specific drugs rescue apoptosis of DYT16 cells after ER stress. Aim 3: Identify, validate and test small molecule inhibitors of PKR for protecting ER stress-induced apoptosis in DYT16 and DID. • Screen a small molecule chemical compound library for PKR inhibition. • Validate the identified candidate compounds using biochemical and cellular assays. • Investigate their protective effect in DYT16 cells and in cells treated with antipsychotic drugs. Study Design: We will use two cell culture models, normal (wild-type, control) and DYT16 patient lymphoblasts and neuroblastoma SH-SY5Y cell line. Using various biochemical and molecular techniques, we will determine if luteolin, PKR inhibitors, and eIF2 alpha pathway-specific drugs can restore cellular homeostasis. Long-Term and Short-Term Impact to the Research Field and Patient Populations: In the short term, our research will clarify the functional role of PKR in chronic ER stress in DYT16 and DID, aspects that have remained unexplored and will be valuable for basic research and drug development. In the long term, our studies will lead to novel therapies for multiple forms of inherited dystonia and DID. Relevance to Military Health: The proposed research is directl
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 28, 2022
- Source ID
- W81XWH2210526
Entities
People
- Rekha C Patel
Organizations
- United States Army
- University of South Carolina