1
|
Yeudall S, Upchurch CM, Leitinger N. The clinical relevance of heme detoxification by the macrophage heme oxygenase system. Front Immunol 2024; 15:1379967. [PMID: 38585264 PMCID: PMC10995405 DOI: 10.3389/fimmu.2024.1379967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 03/11/2024] [Indexed: 04/09/2024] Open
Abstract
Heme degradation by the heme oxygenase (HMOX) family of enzymes is critical for maintaining homeostasis and limiting heme-induced tissue damage. Macrophages express HMOX1 and 2 and are critical sites of heme degradation in healthy and diseased states. Here we review the functions of the macrophage heme oxygenase system and its clinical relevance in discrete groups of pathologies where heme has been demonstrated to play a driving role. HMOX1 function in macrophages is essential for limiting oxidative tissue damage in both acute and chronic hemolytic disorders. By degrading pro-inflammatory heme and releasing anti-inflammatory molecules such as carbon monoxide, HMOX1 fine-tunes the acute inflammatory response with consequences for disorders of hyperinflammation such as sepsis. We then discuss divergent beneficial and pathological roles for HMOX1 in disorders such as atherosclerosis and metabolic syndrome, where activation of the HMOX system sits at the crossroads of chronic low-grade inflammation and oxidative stress. Finally, we highlight the emerging role for HMOX1 in regulating macrophage cell death via the iron- and oxidation-dependent form of cell death, ferroptosis. In summary, the importance of heme clearance by macrophages is an active area of investigation with relevance for therapeutic intervention in a diverse array of human diseases.
Collapse
Affiliation(s)
- Scott Yeudall
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, United States
- Medical Scientist Training Program, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Clint M. Upchurch
- Department of Neuroscience, Center for Brain Immunology and Glia (BIG), University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Norbert Leitinger
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, United States
- Robert M Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, United States
| |
Collapse
|
2
|
Vallelian F, Buehler PW, Schaer DJ. Hemolysis, free hemoglobin toxicity, and scavenger protein therapeutics. Blood 2022; 140:1837-1844. [PMID: 35660854 PMCID: PMC10653008 DOI: 10.1182/blood.2022015596] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/27/2022] [Indexed: 11/20/2022] Open
Abstract
During hemolysis, erythrophagocytes dispose damaged red blood cells. This prevents the extracellular release of hemoglobin, detoxifies heme, and recycles iron in a linked metabolic pathway. Complementary to this process, haptoglobin and hemopexin scavenge and shuttle the red blood cell toxins hemoglobin and heme to cellular clearance. Pathological hemolysis outpaces macrophage capacity and scavenger synthesis across a diversity of diseases. This imbalance leads to hemoglobin-driven disease progression. To meet a void in treatment options, scavenger protein-based therapeutics are in clinical development.
Collapse
Affiliation(s)
- Florence Vallelian
- Division of Internal Medicine, University Hospital, University of Zurich, Zurich, Switzerland
| | - Paul W. Buehler
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD
- Center for Blood Oxygen Transport and Hemostasis, University of Maryland School of Medicine, Baltimore, MD
| | - Dominik J. Schaer
- Division of Internal Medicine, University Hospital, University of Zurich, Zurich, Switzerland
| |
Collapse
|
3
|
Humar R, Schaer DJ, Vallelian F. Erythrophagocytes in hemolytic anemia, wound healing, and cancer. Trends Mol Med 2022; 28:906-915. [PMID: 36096988 DOI: 10.1016/j.molmed.2022.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/11/2022] [Accepted: 08/11/2022] [Indexed: 11/18/2022]
Abstract
Hemolysis is a ubiquitous pathology defined as premature red blood cell destruction within the circulation or local tissues. One of the most archetypal functions of macrophages is phagocytosis of damaged or extravasated red blood cells, preventing the extracellular release of toxic hemoglobin and heme. Upon erythrophagocytosis, spiking intracellular heme concentrations drive macrophage transformation into erythrophagocytes, leveraging antioxidative and iron recycling capacities to defend against hemolytic stress. This unique phenotype transformation is coordinated by a regulatory network comprising the transcription factors BACH1, SPI-C, NRF2, and ATF1. Erythrophagocytes negatively regulate inflammation and immunity and may modulate disease-specific outcomes in hemolytic anemia, wound healing, atherosclerosis, and cancer. In this opinion article, we outline the known and presumed functions of erythrophagocytes and their implications for therapeutic innovation and research.
Collapse
Affiliation(s)
- Rok Humar
- Department of Internal Medicine, University Hospital and University of Zurich, Zurich, Switzerland
| | - Dominik J Schaer
- Department of Internal Medicine, University Hospital and University of Zurich, Zurich, Switzerland
| | - Florence Vallelian
- Department of Internal Medicine, University Hospital and University of Zurich, Zurich, Switzerland.
| |
Collapse
|
4
|
Liu J, Zhu Z, Leung GKK. Erythrophagocytosis by Microglia/Macrophage in Intracerebral Hemorrhage: From Mechanisms to Translation. Front Cell Neurosci 2022; 16:818602. [PMID: 35237132 PMCID: PMC8882619 DOI: 10.3389/fncel.2022.818602] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/10/2022] [Indexed: 12/17/2022] Open
Abstract
Intracerebral hemorrhage (ICH) is a devastating condition characterized by hematoma related mass effect. Microglia/macrophage (M φ) are rapidly recruited in order to remove the red blood cells through erythrophagocytosis. Efficient erythrophagocytosis can detoxify hemolytic products and facilitate neurological recovery after ICH. The underlying mechanisms include modulation of inflammatory response and oxidative stress, among others. It is a dynamic process mediated by a cascade of signal transduction, including “find-me” signals, “eat-me” signals and a set of phagocytotic receptors-ligand pairs that may be exploited as therapeutic targets. This review summarizes mechanistic signaling pathways of erythrophagocytosis and highlights the potential of harnessing M φ-mediated phagocytosis for ICH treatment.
Collapse
Affiliation(s)
- Jiaxin Liu
- Department of Surgery, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, Hong Kong SAR, China
| | - Zhiyuan Zhu
- Department of Surgery, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, Hong Kong SAR, China
- Department of Functional Neurosurgery, The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, The Neurosurgery Institute of Guangdong Province, Guangzhou, China
- Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Gilberto Ka-Kit Leung
- Department of Surgery, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, Hong Kong SAR, China
- *Correspondence: Gilberto Ka-Kit Leung,
| |
Collapse
|
5
|
Walter ERH, Cooper SM, Boyle JJ, Long NJ. Enzyme-activated probes in optical imaging: a focus on atherosclerosis. Dalton Trans 2021; 50:14486-14497. [PMID: 34605500 PMCID: PMC8546924 DOI: 10.1039/d1dt02198b] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/27/2021] [Indexed: 12/16/2022]
Abstract
Enzyme-activated probes enable complex biological processes to be studied in real-time. A wide range of enzymes are modulated in diseases, including cancer, inflammatory diseases and cardiovascular disease, and have the potential to act as vital diagnostic and prognostic biomarkers to monitor and report on disease progression. In this perspective article, we discuss suitable design characteristics of enzyme-activated fluorescent probes for ex vivo and in vivo optical imaging applications. With a particular focus on atherosclerosis imaging, we highlight recent approaches to report on the activity of cathepsins (K and B), matrix metalloproteinases (MMP-2 and MMP-9), thrombin, heme oxygenase-1 (HO-1) and myeloperoxidase (MPO).
Collapse
Affiliation(s)
- Edward R H Walter
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 0BZ, UK.
- National Heart and Lung Institute, Imperial College London, London, W12 0NN, UK
| | - Saul M Cooper
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 0BZ, UK.
- National Heart and Lung Institute, Imperial College London, London, W12 0NN, UK
| | - Joseph J Boyle
- National Heart and Lung Institute, Imperial College London, London, W12 0NN, UK
| | - Nicholas J Long
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 0BZ, UK.
| |
Collapse
|
6
|
Pfefferlé M, Ingoglia G, Schaer CA, Hansen K, Schulthess N, Humar R, Schaer DJ, Vallelian F. Acute Hemolysis and Heme Suppress Anti-CD40 Antibody-Induced Necro-Inflammatory Liver Disease. Front Immunol 2021; 12:680855. [PMID: 34054870 PMCID: PMC8149790 DOI: 10.3389/fimmu.2021.680855] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/22/2021] [Indexed: 12/21/2022] Open
Abstract
Clearance of red blood cells and hemoproteins is a key metabolic function of macrophages during hemolytic disorders and following tissue injury. Through this archetypical phagocytic function, heme is detoxified and iron is recycled to support erythropoiesis. Reciprocal interaction of heme metabolism and inflammatory macrophage functions may modify disease outcomes in a broad range of clinical conditions. We hypothesized that acute hemolysis and heme induce acute anti-inflammatory signals in liver macrophages. Using a macrophage-driven model of sterile liver inflammation, we showed that phenylhydrazine (PHZ)-mediated acute erythrophagocytosis blocked the anti-CD40 antibody-induced pathway of macrophage activation. This process attenuated the inflammatory cytokine release syndrome and necrotizing hepatitis induced by anti-CD40 antibody treatment of mice. We further established that administration of heme-albumin complexes specifically delivered heme to liver macrophages and replicated the anti-inflammatory effect of hemolysis. The anti-inflammatory heme-signal was induced in macrophages by an increased intracellular concentration of the porphyrin independently of iron. Overall, our work suggests that induction of heme-signaling strongly suppresses inflammatory macrophage function, providing protection against sterile liver inflammation.
Collapse
Affiliation(s)
- Marc Pfefferlé
- Division of Internal Medicine, University of Zurich, Zurich, Switzerland
| | - Giada Ingoglia
- Division of Internal Medicine, University of Zurich, Zurich, Switzerland
| | | | - Kerstin Hansen
- Division of Internal Medicine, University of Zurich, Zurich, Switzerland
| | - Nadja Schulthess
- Division of Internal Medicine, University of Zurich, Zurich, Switzerland
| | - Rok Humar
- Division of Internal Medicine, University of Zurich, Zurich, Switzerland
| | - Dominik J Schaer
- Division of Internal Medicine, University of Zurich, Zurich, Switzerland
| | - Florence Vallelian
- Division of Internal Medicine, University of Zurich, Zurich, Switzerland
| |
Collapse
|
7
|
Posttraumatic Pancreatitis Four Days after Renal Injury with Massive Retroperitoneal Hematoma. Case Rep Emerg Med 2021; 2021:6693259. [PMID: 34040811 PMCID: PMC8121604 DOI: 10.1155/2021/6693259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 04/16/2021] [Accepted: 04/30/2021] [Indexed: 11/17/2022] Open
Abstract
A 25-year-old man accidentally fell from a cliff and hit his right flank on the ground while camping. Initially, he was able to barely walk, but he ultimately became unable to walk at all due to severe flank pain. He had no remarkable personal or family history and was a social drinker. Upon arrival, he showed clear consciousness but was in a hemorrhagic shock state. Enhanced computed tomography (CT) revealed extravasation of contrast medium from the injured right kidney with massive retroperitoneal hematoma. He underwent massive blood transfusion and tracheal intubation followed by renal embolization. His vital signs stabilized on hospital day 2, and he was extubated on day 3. On days 4 and 5, a blood examination revealed increased levels of amylase (360 and 904 IU/L, respectively). Enhanced CT on day 5 did not show signs of severe acute pancreatitis. The maximum amylase level was 1041 IU/L on day 6 and decreased day by day without deterioration of the severity of his acute pancreatitis. He was discharged on day 14. The subacute phase of posttraumatic acute pancreatitis in the present case may have been induced not by direct injury to the pancreas but by several causative factors, such as shock, increased pressure of the retroperitoneal space, or the release of inflammatory mediators from injured tissues or hematoma.
Collapse
|