Title: Novel high resolution insights into mitochondrial dysfunction in acute pancreatitis within and beyond the pancreas
Funder: Guts UK

Abstract: Acute Pancreatitis (AP) is a common disease and the severe form carries significant morbidity, a mortality >20% and lacks specific drug treatment. An impediment to breakthroughs in drug discovery has been our inability to resolve the heterogeneity in patient response to initial pancreatic injury. Patients with severe AP can have pronounced systemic injury without significant pancreatic necrosis and vice-versa, indicating a range of cellular responses must exist. The Liverpool Pancreatitis Research Group has taken a leading international role in discovering that pancreatic mitochondrial injury, mediated through the mitochondrial permeability transition pore (MPTP), is a critical feature of severe AP. Whole body cyclophilin D (CypD, a key MPTP regulator) knockout mice (Ppif-/- mice) are protected from mitochondrial injury and maintain cellular ATP, resulting in a markedly reduced severity of experimental AP. Although CypD is a key regulator of the MPTP, controversy still exists with regards its precise functions within the mitochondria and indeed the cell overall. A better mechanistic understanding of CypD expression, movement and response in AP would significantly enhance drug discovery and help minimize off-target effects. Furthermore, whether the benefit of CypD regulated mitochondrial protection is as a result of effects in the pancreas, other cells and organs or both, remains unclear. Extra-pancreatic mitochondrial failure in AP has been observed but to what extent it contributes to the severity of AP remains unclear. This is a crucial research question that must be answered to allow a nuanced approach to drug development. The aim of this study is to determine the contribution to AP, particularly to severe AP, of extra_x0002_pancreatic mitochondrial injury, specifically in the immune system and lungs. This will be achieved through characterization of a transgenic mouse model developed using the latest CRISPR Cas9 genetic manipulation techniques displaying selective extra-pancreatic mitochondrial protection through pancreas-specific expression of CypD on a whole body Ppif-/- background. Cutting-edge high resolution microscopy will be used to assess spatio-temporal responses of CypD to in vitro experimental AP models in isolated pancreatic acinar cells, followed by assessment of the novel transgenic mouse model in a range of in vivo experimental AP models. Finally, the latest single_x0002_cell transcriptomics platforms will be used to dissect out and resolve the heterogeneity in cellular responses resulting from selective extra-pancreatic mitochondrial protection at the innate immune interface in early pancreatitis by examining pancreas, blood and lung cell isolates. These ultra_x0002_high resolution approaches will provide an understanding of the role of mitochondrial dysfunction in AP in more impactful detail, furthering ongoing attempts at translational drug discovery using promising mitochondrial protective agents and providing key information that will influence timing of administration and bioavailability for any compounds with potential.


Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: ORAL AND GASTROINTESTINAL