Benefits of Eliminating Cell Death Pathways in Health and Disease

描述（由申请人提供）：消除健康和疾病中的细胞死亡途径的好处影响血管健康的潜在过程在很大程度上仍未定义，导致目前的治疗干预措施治疗症状，而没有准确理解潜在的、生理相关的疾病和再生途径。我们建议通过消除非重要细胞死亡和相关炎症过程来限制炎症并协调造血和心血管组织的修复和再生。我们发现，小鼠体内Casp8 （Casp8）缺乏的胚胎致死性是由RIP3坏死释放引起的，这为利用消除这些途径的益处开辟了道路。Casp8-/- Rip3-/- (DKO)小鼠发育成可存活和可生育的成年小鼠，缺乏对炎症损伤的易感性

DESCRIPTION (provided by applicant): Benefits of Eliminating Cell Death Pathways in Health and Disease the underlying processes influencing vascular health remain largely undefined, leaving current therapeutic interventions to treat symptoms without a precise understanding the underlying, physiologically relevant disease and regenerative pathways. We propose to restrict inflammation and orchestrate repair and regeneration of hematopoietic and cardiovascular tissues by eliminating nonvital cell death and associated inflammatory processes. Our discovery that embryonic lethality of caspase 8 (Casp8)-deficiency in mice results from unleashed RIP3 necrosis opens the path to harnessing benefits of eliminating these pathways. Casp8-/- Rip3-/- (DKO) mice develop into viable and fertile adults that lack a susceptibility to inflammatory insult but retain sufficient immune function to control viral infection, prompting pilot efforts to harnes this setting to improve tissue repair, allogeneic engraftment and tissue regeneration. The Casp8 and RIP3 pathways evolved to counteract virus-encoded cell death suppressors, but become unleashed to cause inflammatory disease and undermine tissue repair, homeostasis and regeneration. This proposal employs genetic as well as small molecule approaches to eliminate cell death pathways, all modeled by DKO mice, as well as a additional mouse strains we have created. We have already shown that DKO mice resist acute inflammation, inflammatory cancer and ischemia reperfusion injury even though overall wound repair rates appear normal, prompting the very important question, "How can benefit(s) from life in the absence of extrinsic cell death pathways be harnessed in the clinic"? DKO cells engraft and differentiate with higher efficiencies than WT cells. Remarkably, Casp8-/-Rip3-/- mice survive allogeneic (MHC mismatched) bone marrow engraftment that causes acute graft versus host disease (GvHD) in WT C57BL/6 mice. Surprisingly, DKO fibroblasts support nuclear reprogramming with improved efficiency over WT cells. We propose to eliminate deleterious consequences of cell death through genetic manipulation, moving this area closer to a therapeutic intervention strategy to improve hematopoietic and cardiovascular tissue repair and regeneration. We propose to investigate genetic deficiency in mice and mouse cells, and develop knock-out strategies on rhesus macaque and human fibroblasts to combine with newly described small molecule inhibitors of RIP3 kinase and commercially available caspase inhibitors, to improve tissue repair, allogeneic transplantation and nuclear reprogramming. Our Aims are to: (1) optimize allogeneic engraftment, and (2) enhance nuclear reprogramming by eliminating extrinsic apoptosis without the disadvantage of triggering necrosis. The knowledge gained through these studies will have broad impact in current tissue repair and transplantation approaches, as well as future regenerative medicine strategies.