Lamade, Andrew
(2020)
Role of Regulated Necrotic Cell Death in Acute Injury:
Ferroptosis, Necroptosis, Parthanatos.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Regulated necrotic cell death (RND) is a core feature of acute disease. Cells recognized as a liability to the organism are eliminated deliberately through genetically predetermined and tightly regulated mechanisms. Each death mode is initiated and propagated by distinct molecular mechanisms but, to varying degrees, are all interconnected. RND is a subset classification for all non-apoptotic death mechanisms, which are morphologically necrotic and immunogenic. The pro-inflammatory nature of RNDs hints to their physiologic antimicrobial and anti-neoplastic roles. However, acute pathology yields excessive RND that exacerbates and prolongs tissue dysfunction. The cycle of RND, inflammation, and secondary RND persists days to weeks after the inciting injury and is a clinically relevant therapeutic target. Ferroptosis, necroptosis, and parthanatos are three established RND mechanisms that cooperate across a range of diseases in vivo. Understanding the precise mechanisms and (co)regulation schemas for these pathways will enable more rational drug design and application.
In the first part of this work, we interrogate the role of mitochondrial Poly(ADP-ribose) polymerase (mtPARP1) in parthanotic ischemia-reperfusion and oxidative neuronal injury. Oxidative insult activates mtPARP1, which consumes nicotinamide adenine dinucleotide (NAD+) and poly-ADP-ribosylates mitochondrial proteins. The action of mtPARP1 exacerbates mitochondrial pathology. In contrast, nuclear PARP1 preserves genomic DNA integrity. We developed a novel neuroprotective mitochondria-targeted PARP inhibitor, XJB-veliparib, which localizes specifically to the inner mitochondrial membrane and matrix. XJB-veliparib preserves mitochondrial morphology and NAD+ without hindering nuclear DNA repair. XJB-veliparib provides an opportunity to integrate mtPARP1 pathology and enables the development of clinically effective anti-parthanotic therapies.
In the second part of this work, we provide the first mechanistic reasoning for the interaction between ferroptosis and necroptosis. We demonstrate through computational, genetic, biochemical, and redox lipidomics approaches that phosphatidylethanolamine binding protein 1 (PEBP1) coregulates the ferroptosis and necroptosis death programs in vitro and in vivo. PEBP1 allosterically regulates RIP3 kinase activity to inhibit necroptosis. Genetic or pharmacologic conditions that dissociate PEBP1 from RIP3 and other binding partners promote ferroptosis. Interaction of PEBP1 with 15-lipoxygnease (15LOX) enables ferroptotic arachidonoyl-phosphatidylethanolamine (AA-PE) peroxidation. Our work indicates that anti-RND therapies must simultaneously target the ferroptosis and necroptosis pathways to maximize clinical benefit.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
12 September 2020 |
| Date Type: |
Publication |
| Defense Date: |
17 August 2020 |
| Approval Date: |
12 September 2020 |
| Submission Date: |
1 September 2020 |
| Access Restriction: |
2 year -- Restrict access to University of Pittsburgh for a period of 2 years. |
| Number of Pages: |
180 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Medicine > Molecular Pharmacology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Ferroptosis; Necroptosis; Parthanatos; XJB-veliparib |
| Date Deposited: |
12 Sep 2020 11:55 |
| Last Modified: |
23 Mar 2023 17:29 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/39700 |
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