Prolyl hydroxylase 2 inactivation enhances glycogen storage and promotes excessive neutrophilic responses
Pranvera Sadiku, … , Moira K.B. Whyte, Sarah R. Walmsley
Pranvera Sadiku, … , Moira K.B. Whyte, Sarah R. Walmsley
Published August 14, 2017
Citation Information: J Clin Invest. 2017;127(9):3407-3420. https://doi.org/10.1172/JCI90848.
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Research Article Inflammation Metabolism

Prolyl hydroxylase 2 inactivation enhances glycogen storage and promotes excessive neutrophilic responses

Abstract

Fully activated innate immune cells are required for effective responses to infection, but their prompt deactivation and removal are essential for limiting tissue damage. Here, we have identified a critical role for the prolyl hydroxylase enzyme Phd2 in maintaining the balance between appropriate, predominantly neutrophil-mediated pathogen clearance and resolution of the innate immune response. We demonstrate that myeloid-specific loss of Phd2 resulted in an exaggerated inflammatory response to Streptococcus pneumonia, with increases in neutrophil motility, functional capacity, and survival. These enhanced neutrophil responses were dependent upon increases in glycolytic flux and glycogen stores. Systemic administration of a HIF–prolyl hydroxylase inhibitor replicated the Phd2-deficient phenotype of delayed inflammation resolution. Together, these data identify Phd2 as the dominant HIF-hydroxylase in neutrophils under normoxic conditions and link intrinsic regulation of glycolysis and glycogen stores to the resolution of neutrophil-mediated inflammatory responses. These results demonstrate the therapeutic potential of targeting metabolic pathways in the treatment of inflammatory disease.

Authors

Pranvera Sadiku, Joseph A. Willson, Rebecca S. Dickinson, Fiona Murphy, Alison J. Harris, Amy Lewis, David Sammut, Ananda S. Mirchandani, Eilise Ryan, Emily R. Watts, A.A. Roger Thompson, Helen M. Marriott, David H. Dockrell, Cormac T. Taylor, Martin Schneider, Patrick H. Maxwell, Edwin R. Chilvers, Massimilliano Mazzone, Veronica Moral, Chris W. Pugh, Peter J. Ratcliffe, Christopher J. Schofield, Bart Ghesquiere, Peter Carmeliet, Moira K.B. Whyte, Sarah R. Walmsley

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Figure 7

Non-PHD isoform-selective inhibition in vivo replicates the Phd2-deficient phenotype of augmented neutrophilic inflammation.

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Non-PHD isoform-selective inhibition in vivo replicates the Phd2-deficie...
WT mice were treated with the HIF-prolyl hydroxylase inhibitor molidustat (5 mg/kg) or vehicle control (DMSO) by gavage 2 hours (T–2) prior to challenge with nebulized LPS (3 mg) (T0). (A and B) Whole blood was harvested at T48 for percentage of reticulocyte counts (A) and packed cell volume measurements (B). (C and D) Recruitment. Mice were sacrificed 6 hours after LPS installation (T6) and total cell counts in BAL were determined (C). The chemotactic mobility of neutrophils recovered from the BAL toward KC was determined ex vivo using neuroprobe chambers (D). (E and F) Resolution. Twenty-four hours after the initial molidustat dosing (T22), a second dose of molidustat (5 mg/kg) was administered by gavage and animals sacrificed after a further 22-hour period (T48). BAL total cell counts (E) and neutrophil (F) total counts were performed. (G and H) Twenty-four hours after LPS challenge, mice (T24) were sacrificed and bone marrow neutrophils harvested for Seahorse quantification of ECARs (basal ECAR levels shown) (G). ATP levels were measured in BAL neutrophils by LC-MS (H). Data represent mean ± SEM of at least 4 independent experiments, with significance determined by unpaired t test.