Necrosis is considered to be an unregulated and chaotic cell death. However, recent advances in cell death strategies support necroptosis as a form of regulated programmed necrotic cell death. In response to TNF-a or Fas ligands, necroptosis can be induced by cell death receptors in multiple cell lines in the presence of a caspase inhibitor z-VAD; necroptotic cell death has been found to play an important role in normal development, immunity, inflammation, cancer, and human diseases. In this chapter, the molecular mechanisms governing necroptosis, recent findings about the upstream and downstream schema of necroptosis, and potential therapeutic targets in neurological disorders are discussed. After being activated by TNF-a (or Fas ligands) and death receptors, receptor-interacting proteins 1 and 3 (RIP1 and RIP3) form a complex, which play a central role in the induction of necroptosis. RIP3 phosphorylates and activates mitochondrial proteins mixed lineage kinase domain-like protein (MLKL) and PGAM5, resulting in the execution of necroptosis by dynamin-related protein 1, the GTPase that controls mitochondrial fission. Some small molecules such as necrostain-1 and necrosulfonamide target different steps of necroptosis and impede the progress of necroptosis. FADD, caspase-8, CLIP, and CYLD positively or negatively regulate RIP1-/RIP3-dependent necroptosis by different mechanisms. Recent studies demonstrate the involvement of necroptosis in many neurological disorders including stroke, trauma, neonatal hypoxic-ischemic encephalopathy, and Huntington's disease. As a potential therapeutic target, the understanding of necroptotic mechanisms will provide new insights to develop more potent neuroprotectants and specific therapeutic strategies for clinical treatments of neurological disorders.

abstract: Since the molecular biology revolution in the 1980s, ease of gene editing had led to the resurgence of Oncolytic Virotherapy. Countless viruses have been engineered yet only three are approved for clinical use worldwide, with only one being approved by the U.S Food and Drug Administration (FDA). Vaccinia virus (VACV) has a large genome, contains many immune evasion genes and has been thoroughly studied, making it a popular candidate for an oncolytic platform. VACV mutants with deletions in the E3 immune evasion protein have been shown to have oncolytic efficacy but the mechanism of tumor selectivity has not been fully elucidated. These mutants have been shown to be regulated by the necroptosis pathway, a pathway that has been shown to be deficient in certain cancers. Using a pan-cancer screening method that combines dye exclusion assays, western blot analysis, and viral growth curve, the role of necroptosis in regulating VACV replication and oncolytic efficacy in cancer was further characterized. Results demonstrate a preliminary correlation between necroptosis, viral replication, and oncolytic efficacy. This correlation is clearest in breast cancer and melanomas yet may apply to other cancer subgroups. This data was also used to guide the development of a receptor-interacting protein kinase 3 (RIP3) matched pair mouse model in the E0771 mouse breast cancer line which can be used to further study the role of necroptosis and oncolytic efficacy in vivo. Understanding the contribution necroptosis plays in oncolytic efficacy can guide to design enhance the design of clinical trials to test VACV E3L mutants and may lead to better efficacy in humans and an improvement in clinical oncology. / Dissertation/Thesis / Masters Thesis Biology 2020