Knockout of the Mitochondrial Calcium Uniporter Strongly Suppresses Stimulus-Metabolism Coupling in Pancreatic Acinar Cells but Does Not Reduce Severity of Experimental Acute Pancreatitis
Michael Chvanov,
Svetlana Voronina,
Xiaoying Zhang,
Svetlana Telnova,
Robert Chard,
Yulin Ouyang,
Jane Armstrong,
Helen Tanton,
Muhammad Awais,
Diane Latawiec,
Robert Sutton,
David N. Criddle,
Alexei V. Tepikin
Affiliations
Michael Chvanov
Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, UK
Svetlana Voronina
Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, UK
Xiaoying Zhang
Liverpool Pancreatitis Research Group, Royal Liverpool University Hospital, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
Svetlana Telnova
Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, UK
Robert Chard
Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, UK
Yulin Ouyang
Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, UK
Jane Armstrong
Liverpool Pancreatitis Research Group, Royal Liverpool University Hospital, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
Helen Tanton
Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, UK
Muhammad Awais
Liverpool Pancreatitis Research Group, Royal Liverpool University Hospital, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
Diane Latawiec
Liverpool Pancreatitis Research Group, Royal Liverpool University Hospital, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
Robert Sutton
Liverpool Pancreatitis Research Group, Royal Liverpool University Hospital, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
David N. Criddle
Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, UK
Alexei V. Tepikin
Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool L69 3BX, UK
Acute pancreatitis is a frequent disease that lacks specific drug treatment. Unravelling the molecular mechanisms of acute pancreatitis is essential for the development of new therapeutics. Several inducers of acute pancreatitis trigger sustained Ca2+ increases in the cytosol and mitochondria of pancreatic acinar cells. The mitochondrial calcium uniporter (MCU) mediates mitochondrial Ca2+ uptake that regulates bioenergetics and plays an important role in cell survival, damage and death. Aberrant Ca2+ signaling and mitochondrial damage in pancreatic acinar cells have been implicated in the initiation of acute pancreatitis. The primary aim of this study was to assess the involvement of the MCU in experimental acute pancreatitis. We found that pancreatic acinar cells from MCU−/− mice display dramatically reduced mitochondrial Ca2+ uptake. This is consistent with the drastic changes of stimulus-metabolism coupling, manifested by the reduction of mitochondrial NADH/FAD+ responses to cholecystokinin and in the decrease of cholecystokinin-stimulated oxygen consumption. However, in three experimental models of acute pancreatitis (induced by caerulein, taurolithocholic acid 3-sulfate or palmitoleic acid plus ethanol), MCU knockout failed to reduce the biochemical and histological changes characterizing the severity of local and systemic damage. A possible explanation of this surprising finding is the redundancy of damaging mechanisms activated by the inducers of acute pancreatitis.
