Necrosis, a catastrophic cell death caused by overwhelming stress, is a major contributor to human disease. However, very little effort has been made to develop therapies targeting pathologic necrosis due to its perceived uncontrollable nature. This notion has been recently challenged through the discovery that necrosis can result from the activation of intrinsic cellular regulatory pathways, suggesting that necrosis can be specifically targeted for inhibition. As a direct demonstration of the feasibility of this approach, we have developed potent and selective small molecule inhibitors of such regulated necrosis or """"""""necroptosis"""""""". Furthermore, we have used one of these molecules, Necrostatin-1, to demonstrate that necroptosis is an important component of acute pathologic injury in vivo in the case of ischemic brain and heart damage and endotoxic liver destruction. Discovery of necrostatins provides an unprecedented opportunity to develop novel necrosis-specific therapies for human disease. In Preliminary studies, we identified five structurally distinct necrostatins in a cell based high-throughput screen of 100,000+ compounds. Surprisingly, all necrostatins inhibit necroptosis at the level of RIP kinase complex, an established mediator of necroptosis induction, suggesting that it is a key step of this pathway susceptible to inhibition. Interestingly, while all necrostatins act through a similar target, they display distinct activities in different cells, suggesting the possibility of developing cell type-specific inhibitors. In this proposal, we will further investigate the mechanism of necrostatins'activity in vitro and in vivo.
In Aim 1, we will investigate in vitro interactions of necrostatins with RIP and associated factors using combination of biochemical, mass spectrometry, medicinal chemistry and structural biology methods.
In Aim 2, we will apply the insights from Aim 1 to identify key parameters defining differential cellular sensitivity to necrostatins in order to develop specific markers for predicting optimal strategy for necroptosis suppression in various paradigms of pathologic necrosis.
In Aim 3, we propose to study how in vitro activities of necrostatins translate into therapeutic benefit in the animal model of acute liver injury. Overall, our project should further define necroptosis as the key component of pathologic injury and provide mechanistic basis for development of novel necroptosis-specific therapies.
Necrosis is a key component of acute tissue injury in many human diseases from stroke and myocardial infarction to septic shock. The goal of our proposal is to characterize the mechanism of action of novel chemical inhibitors of cellular necrosis, identified in our preliminary studies, and establish their potential as therapeutic agents in animal models of human disease. These molecules may present a principally novel direction for drug development for many devastating human disorders.
|Wegner, Kelby W; Saleh, Danish; Degterev, Alexei (2017) Complex Pathologic Roles of RIPK1 and RIPK3: Moving Beyond Necroptosis. Trends Pharmacol Sci 38:202-225|
|Saleh, Danish; Najjar, Malek; Zelic, Matija et al. (2017) Kinase Activities of RIPK1 and RIPK3 Can Direct IFN-? Synthesis Induced by Lipopolysaccharide. J Immunol 198:4435-4447|
|Degterev, Alexei; Linkermann, Andreas (2016) Generation of small molecules to interfere with regulated necrosis. Cell Mol Life Sci 73:2251-67|
|Najjar, Malek; Saleh, Danish; Zelic, Matija et al. (2016) RIPK1 and RIPK3 Kinases Promote Cell-Death-Independent Inflammation by Toll-like Receptor 4. Immunity 45:46-59|
|Canning, Peter; Ruan, Qui; Schwerd, Tobias et al. (2015) Inflammatory Signaling by NOD-RIPK2 Is Inhibited by Clinically Relevant Type II Kinase Inhibitors. Chem Biol 22:1174-84|
|Najjar, Malek; Suebsuwong, Chalada; Ray, Soumya S et al. (2015) Structure guided design of potent and selective ponatinib-based hybrid inhibitors for RIPK1. Cell Rep 10:1850-60|
|Degterev, Alexei; Zhou, Wen; Maki, Jenny L et al. (2014) Assays for necroptosis and activity of RIP kinases. Methods Enzymol 545:1-33|
|Dvoriantchikova, Galina; Degterev, Alexei; Ivanov, Dmitry (2014) Retinal ganglion cell (RGC) programmed necrosis contributes to ischemia-reperfusion-induced retinal damage. Exp Eye Res 123:1-7|
|McNamara, Colleen R; Ahuja, Ruchita; Osafo-Addo, Awo D et al. (2013) Akt Regulates TNF? synthesis downstream of RIP1 kinase activation during necroptosis. PLoS One 8:e56576|
|Maki, Jenny L; Tres Brazell, J; Teng, Xin et al. (2013) Expression and purification of active receptor interacting protein 1 kinase using a baculovirus system. Protein Expr Purif 89:156-61|
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