Inhibition of HIF-prolyl hydroxylases improves healing of intestinal anastomoses
Moritz J. Strowitzki, Gwendolyn Kimmer, Julian Wehrmann, Alina S. Ritter, Praveen Radhakrishnan, Vanessa M. Opitz, Christopher Tuffs, Marvin Biller, Julia Kugler, Ulrich Keppler, Jonathan M. Harnoss, Johannes Klose, Thomas Schmidt, Alfonso Blanco, Cormac T. Taylor, Martin Schneider
Moritz J. Strowitzki, Gwendolyn Kimmer, Julian Wehrmann, Alina S. Ritter, Praveen Radhakrishnan, Vanessa M. Opitz, Christopher Tuffs, Marvin Biller, Julia Kugler, Ulrich Keppler, Jonathan M. Harnoss, Johannes Klose, Thomas Schmidt, Alfonso Blanco, Cormac T. Taylor, Martin Schneider
View: Text | PDF
Research Article Gastroenterology Inflammation

Inhibition of HIF-prolyl hydroxylases improves healing of intestinal anastomoses

Abstract

Anastomotic leakage (AL) accounts for a major part of in-house mortality in patients undergoing colorectal surgery. Local ischemia and abdominal sepsis are common risk factors contributing to AL and are characterized by upregulation of the hypoxia-inducible factor (HIF) pathway. The HIF pathway is critically regulated by HIF-prolyl hydroxylases (PHDs). Here, we investigated the significance of PHDs and the effects of pharmacologic PHD inhibition (PHI) during anastomotic healing. Ischemic or septic colonic anastomoses were created in mice by ligation of mesenteric vessels or lipopolysaccharide-induced abdominal sepsis, respectively. Genetic PHD deficiency (Phd1–/–, Phd2+/–, and Phd3–/–) or PHI were applied to manipulate PHD activity. Pharmacologic PHI and genetic PHD2 haplodeficiency (Phd2+/–) significantly improved healing of ischemic or septic colonic anastomoses, as indicated by increased bursting pressure and reduced AL rates. Only Phd2+/– (but not PHI or Phd1–/–) protected from sepsis-related mortality. Mechanistically, PHI and Phd2+/– induced immunomodulatory (M2) polarization of macrophages, resulting in increased collagen content and attenuated inflammation-driven immune cell recruitment. We conclude that PHI improves healing of colonic anastomoses in ischemic or septic conditions by Phd2+/–-mediated M2 polarization of macrophages, conferring a favorable microenvironment for anastomotic healing. Patients with critically perfused colorectal anastomosis or abdominal sepsis could benefit from pharmacologic PHI.

Authors

Moritz J. Strowitzki, Gwendolyn Kimmer, Julian Wehrmann, Alina S. Ritter, Praveen Radhakrishnan, Vanessa M. Opitz, Christopher Tuffs, Marvin Biller, Julia Kugler, Ulrich Keppler, Jonathan M. Harnoss, Johannes Klose, Thomas Schmidt, Alfonso Blanco, Cormac T. Taylor, Martin Schneider

×

Figure 3

Pharmacologic and genetic inhibition of HIF-prolyl hydroxylases improves healing of septic colonic anastomoses.

Options: View larger image (or click on image) Download as PowerPoint
Pharmacologic and genetic inhibition of HIF-prolyl hydroxylases improves...
(A and B) Schematic drawing (A) and experimental schedule (B). LPS was injected i.p. 18 hours prior to creation of anastomoses. Pretreatment with PHI (DMOG, 100 μg/g BW) or vehicle control was performed for 3 days prior to anastomosis and continued for 7 days until evaluation (B, left). Alternatively, LPS injection and surgical anastomosis was performed in WT, Phd1–/–, and Phd2+/– mice, and evaluation was performed 3 days thereafter (B, right). (C and D) Bursting pressure analysis of septic colonic anastomoses from vehicle- or DMOG-treated mice (C) or from WT, Phd1–/–, and Phd2+/– mice (D) (pretreatment: n = 7 animals per group; Student’s t test; knockout model: n = 9–12 animals per group; ANOVA with post hoc test). (E and F) Postoperative disease activity (E) and survival (F) of WT, Phd1–/–, and Phd2+/– mice on days 0–3 after LPS-induced sepsis and colonic anastomosis. Note significantly attenuated disease activity and improved survival in Phd2+/– mice (n = 12–27 animals per group; differences in disease activity score in E were analyzed by 2-way ANOVA with post hoc test and survival curves in F by log-rank test). (G) Representative MTG stainings of collagen capsules (black dashed lines in left upper panels) and immunolabeling of myofibroblasts (αSMA, left lower panels) in healthy and septic (LPS i.p.) anastomoses from WT, Phd1–/–, and Phd2+/– mice and histomorphometric quantification (right) (n = 6–7 animals per group; ANOVA or Kruskal-Wallis test where appropriate; scale bars in top and bottom panels represent 100 μm and 200 μm, respectively; § and # indicate positions of [extracted] sutures and gut lumen, respectively).