Loss or silencing of the PHD1 prolyl hydroxylase protects livers of mice against ischemia/reperfusion injury.

Journal article

BACKGROUND and AIMS: Liver ischemia/reperfusion (I/R) injury is a frequent cause of organ dysfunction. Loss of the oxygen sensor prolyl hydroxylase domain enzyme 1 (PHD1) causes tolerance of skeletal muscle to hypoxia. We assessed whether loss or short-term silencing of PHD1 could likewise induce hypoxia tolerance in hepatocytes and protect them against hepatic I/R damage. METHODS: Hepatic ischemia was induced in mice by clamping of the portal vessels of the left lateral liver lobe; 90 minutes later livers were reperfused for 8 hours for I/R experiments. Hepatocyte damage following ischemia or I/R was investigated in PHD1-deficient (PHD1(-/-)) and wild-type mice or following short hairpin RNA-mediated short-term inhibition of PHD1 in vivo. RESULTS: PHD1(-/-) livers were largely protected against acute ischemia or I/R injury. Among mice subjected to hepatic I/R followed by surgical resection of all nonischemic liver lobes, more than half of wild-type mice succumbed, whereas all PHD1(-/-) mice survived. Also, short-term inhibition of PHD1 through RNA interference-mediated silencing provided protection against I/R. Knockdown of PHD1 also induced hypoxia tolerance of hepatocytes in vitro. Mechanistically, loss of PHD1 decreased production of oxidative stress, which likely relates to a decrease in oxygen consumption as a result of a reprogramming of hepatocellular metabolism. CONCLUSIONS: Loss of PHD1 provided tolerance of hepatocytes to acute hypoxia and protected them against I/R-damage. Short-term inhibition of PHD1 is a novel therapeutic approach to reducing or preventing I/R-induced liver injury.

Authors: Schneider, M; Van Geyte, K; Fraisl, P; Kiss, J; Aragonés, J

• Publication status: Published
• Journal: Gastroenterology
• Volume: 138
• Issue: 3
• Pages: 1143-54.e1-2
• Publication date: 2010-03-01
• DOI: 10.1053/j.gastro.2009.09.057
• EISSN: 1528-0012
• ISSN: 0016-5085
• Language: English
• Keywords: Cell Hypoxia; Gene Knockdown Techniques; Animals; Liver; Adaptation, Physiological; RNA Interference; Male; Basic Helix-Loop-Helix Transcription Factors; Reperfusion Injury; Time Factors; Cells, Cultured; Mice; Oxygen Consumption; Hepatocytes; Disease Models, Animal; Hypoxia-Inducible Factor 1, alpha Subunit; Mice, Knockout; Procollagen-Proline Dioxygenase; Oxidative Stress; Liver Diseases