Hypoxia Responses in Physiology and Pathogenesis

Changes in tissue oxygen levels occur under pathological conditions and physiologically during development. The laboratory of Volker Haase studies hypoxia response pathways and their therapeutic applications.

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Volker Haase Lab

Oxygen logo Volker H Haase Laboratory

The laboratory of Professor Volker Haase studies hypoxia response pathways and their therapeutic applications in erythropoiesis and iron metabolism, kidney injury and ischemic pre-conditioning, inflammation, kidney development and tumorigenesis. A major focus of the lab is on the interplay between hypoxia signaling, metabolism and cellular differentiation and its regulation by the prolyl hydroxylase domain (PHD) / hypoxia-inducible factor (HIF) / von Hippel-Lindau tumor suppressor (VHL) signaling axis. Haase group members take advantage of powerful cutting-edge mouse genetics, biochemical, metabolomic and single cell approaches to study oxygen and mitochondrial metabolism in kidney, urologic and other diseases. Click on links for information about career opportunities in the Haase lab and recent publications.

Mitochondria renal epithelium

Mitochondria in renal epithelium

Epo RNA-FISH Volker Haase Lab

Erythropoietin-producing cells in the kidney
(red fluorescent signal)

Overwiew of oxygen metabolism in renal tissue

Mechanisms of Renal Hypoxia

Epithelial progenitor cells in the developing kidney

Haase Lab in 2017

Lab news and updates

HIF in the prevention of bladder injury

This study from our lab demonstrates that HIF-activating compounds protect from cystitis

May 2022

Inhibition of hypoxia-inducible factor-prolyl hydroxylation protects from cyclophosphamide-induced bladder injury and urinary dysfunction

Disruption of the blood-urine barrier can result in acute or chronic inflammatory bladder injury. Activation of the oxygen-regulated hypoxia-inducible factor (HIF) pathway has been shown to protect mucosal membranes by increasing the expression of cytoprotective genes and by suppressing inflammation. The activity of HIF is controlled by prolyl hydroxylase domain (PHD) dioxygenases, which have been exploited as therapeutic targets for the treatment of anemia of chronic kidney disease. Here we established a mouse model of acute cyclophosphamide (CYP)-induced blood-urine barrier disruption associated with inflammation and severe urinary dysfunction to investigate the HIF-PHD axis in inflammatory bladder injury. We found that systemic administration of dimethyloxalylglycine (DMOG) or molidustat, two small molecule inhibitors of HIF-prolyl hydroxylases (HIF-PHIs), profoundly mitigated CYP-induced bladder injury and inflammation as assessed by morphologic analysis of transmural edema and urothelial integrity and by measuring tissue cytokine expression. > …

EPO synthesis in CKD kidneys is limited by myofibroblast transdifferentiation

This study from our lab demonstrates that HIF-PHIs do not stimulate EPO production in myofibroblasts

May 2022

EPO synthesis induced by HIF-PHD inhibition is dependent on myofibroblast transdifferentiation and colocalizes with non-injured nephron segments in murine kidney fibrosis

Erythropoietin (EPO) is regulated by hypoxia-inducible factor (HIF)-2. In the kidney, it is produced by cortico-medullary perivascular interstitial cells, which transdifferentiate into collagen-producing myofibroblasts in response to injury. Inhibitors of prolyl hydroxylase domain (PHD) dioxygenases (HIF-PHIs) activate HIF-2 and stimulate kidney and liver EPO synthesis in patients with anemia of chronic kidney disease (CKD). We examined whether HIF-PHIs can reactivate EPO synthesis in interstitial cells that have undergone myofibroblast transdifferentiation in established kidney fibrosis. > …

Anemia of CKD

Commentary: Iron absorption

April 2022

The ins and outs of ferric citrate

Ferric citrate is used clinically for the treatment of hyperphosphatemia in patients with chronic kidney disease and is approved as an oral iron replacement product for patients with iron-deficiency anemia. In this issue of Kidney International, Hanudel and colleagues take advantage of genetic models with and without chronic kidney injury to demonstrate that the enteric absorption of iron delivered by ferric citrate is dependent on ferroportin expression and does not involve paracellular iron transport. > …

Mitochondrial electron transport in renal development

This study from our lab identifies a differential role for mitochondrial electron transport in renal progenitors

March 2022

Disruption of mitochondrial complex III in cap mesenchyme but not in ureteric progenitors results in defective nephrogenesis associated with amino acid deficiency.

Oxidative metabolism in mitochondria regulates cellular differentiation and gene expression through intermediary metabolites and reactive oxygen species. Its role in kidney development and pathogenesis is not completely understood. Here we inactivated ubiquinone-binding protein QPC, a subunit of mitochondrial complex III, in two types of kidney progenitor cells to investigate the role of mitochondrial electron transport in kidney homeostasis. Inactivation of QPC in sine oculis-related homeobox 2 (SIX2)-expressing cap mesenchyme progenitors, which give rise to podocytes and all nephron segments except collecting ducts, resulted in perinatal death from severe kidney dysplasia. > …

New insights into the effects of pharmacological HIF activation on renal hemodynamics

This study from our lab identifies a major role for HIF-dependent NO generation in GFR regulation

April 2021

Pharmacological HIF-PHD inhibition reduces renovascular resistance and increases glomerular filtration by stimulating nitric oxide generation

HIF-activating compounds are currently in late-stage clinical development for the treatment of anemia associated with chronic kidney disease. Although the effects of hypoxia on renal hemodynamics and function have been studied in animal models and in humans living at high altitude, the effects of pharmacologic HIF activation on renal hemodynamics, O2 metabolism and metabolic efficiency are not well understood. This cross-sectional study in healthy rats provides new mechanistic insights into dose-dependent effects of short-term pharmacologic HIF activation on renal hemodynamics, glomerular filtration and O2 metabolism. > …

see commentary: Get use to the -dustats: Roxadustat and molidustat, members of the hypoxia-inducible factor (HIF) Prolyl hydroxylase (PHD) inhibitor drug class promote kidney function, perfusion and oxygenation in rats through nitric oxide [Acta Physiologica 2021].

KDIGO Conference Report on Optimal Anemia Management

April 2021

Controversies in Optimal Anemia Management: Conclusions from a Kidney Disease Improving Global Outcomes (KDIGO) Conference

In 2019, KDIGO decided to convene two Controversies Conferences to review the latest evidence, explore new and ongoing controversies, assess change implications for the current KDIGO anemia guideline, and propose a research agenda. The first conference, described here, focused mainly on iron-related issues, including the contribution of disordered iron homeostasis to the anemia of CKD, diagnostic challenges, available and emerging iron therapies, treatment targets, and patient outcomes. > …

Anemia of CKD

Update on the clinical science of HIF-prolyl hydroxylase inhibitors in anemia of CKD

March 2021

Hypoxia-inducible factor-prolyl hydroyxlase inhibitors in the treatment of anemia of chronic kidney disease

This review summarizes clinical data from current HIF-PHI trials in patients with anemia of CKD, discusses mechanisms of action and pharmacologic properties of HIF-PHIs, and deliberates over safety concerns and potential impact on anemia management in patients with CKD. > …

Mitochondrial transcription factor TFAM in renal cystic disease

This study from our lab uncovered a critical role for TFAM in nephron maturation and renal cytogenesis using mouse genetics

November 2020

Renal epithelial TFAM deficiency results in progressive mitochondrial depletion associated with severe cystic disease

Abnormal mitochondrial function is a well-recognized feature of acute and chronic kidney diseases. To gain insight into the role of mitochondria in kidney homeostasis and pathogenesis, we targeted mitochondrial transcription factor A (TFAM), a protein required for mitochondrial DNA replication and transcription that plays a critical part in the maintenance of mitochondrial mass and function. To examine the consequences of disrupted mitochondrial function in kidney epithelial cells, we inactivated TFAM in sine oculis-related homeobox 2-expressing kidney progenitor cells. > …