Heme oxygenase-1 attenuates acute pulmonary inflammation by decreasing the release of segmented neutrophils from the bone marrow

2014 ◽  
Vol 307 (9) ◽  
pp. L707-L717 ◽  
Author(s):  
Franziska M. Konrad ◽  
Stefan Braun ◽  
Kristian-Christos Ngamsri ◽  
Irene Vollmer ◽  
Jörg Reutershan

Recruiting polymorphonuclear neutrophil granulocytes (PMNs) from circulation and bone marrow to the site of inflammation is one of the pivotal mechanisms of the innate immune system. During inflammation, the enzyme heme oxygenase 1 (HO-1) has been shown to reduce PMN migration. Although these effects have been described in various models, underlying mechanisms remain elusive. Recent studies revealed an influence of HO-1 on different cells of the bone marrow. We investigated the particular role of the bone marrow in terms of HO-1-dependent pulmonary inflammation. In a murine model of LPS inhalation, stimulation of HO-1 by cobalt (III) protoporphyrin-IX-chloride (CoPP) resulted in reduced segmented PMN migration into the alveolar space. In the CoPP group, segmented PMNs were also decreased intravascularly, and concordantly, mature and immature PMN populations were higher in the bone marrow. Inhibition of the enzyme by tin protoporphyrin-IX increased segmented and banded PMN migration into the bronchoalveolar lavage fluid with enhanced PMN release from the bone marrow and aggravated parameters of tissue inflammation. Oxidative burst activity was significantly higher in immature compared with mature PMNs. The chemokine stromal-derived factor-1 (SDF-1), which mediates homing of leukocytes into the bone marrow and is decreased in inflammation, was increased by CoPP. When SDF-1 was blocked by the specific antagonist AMD3100, HO-1 activation was no longer effective in curbing PMN trafficking to the inflamed lungs. In conclusion, we show evidence that the anti-inflammatory effects of HO-1 are largely mediated by inhibiting the release of segmented PMNs from the bone marrow rather than direct effects within the lung.

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Jung-Tung Liu ◽  
Huey-Yi Chen ◽  
Wen-Chi Chen ◽  
Kee-Ming Man ◽  
Yung-Hsiang Chen

The inflammation and oxidative stress of bone marrow-derived proangiogenic cells (PACs), also named endothelial progenitor cells, triggered by hyperglycemia contributes significantly to vascular dysfunction. There is supporting evidence that the consumption of red yeast rice (RYR; Monascus purpureus-fermented rice) reduces the vascular complications of diabetes; however, the underlying mechanism remains unclear. This study aimed to elucidate the effects of RYR extract in PACs, focusing particularly on the role of a potent antioxidative enzyme, heme oxygenase-1 (HO-1). We found that treatment with RYR extract induced nuclear factor erythroid-2-related factor nuclear translocation and HO-1 mRNA and protein levels in PACs. RYR extract inhibited high-glucose-induced (30 mM) PAC senescence and the development of reactive oxygen species (ROS) in a dose-dependent manner. The HO-1 inducer cobalt protoporphyrin IX also decreased high-glucose-induced cell senescence and oxidative stress, whereas the HO-1 enzyme inhibitor zinc protoporphyrin IX and HO-1 small interfering RNA significantly reversed RYR extract-caused inhibition of senescence and reduction of oxidative stress in high-glucose-treated PACs. These results suggest that RYR extract serves as alternative and complementary medicine in the treatment of these diseases, by inducing HO-1, thereby decreasing the vascular complications of diabetes.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Urszula Florczyk-Soluch ◽  
Ewelina Józefczuk ◽  
Jacek Stępniewski ◽  
Karolina Bukowska-Strakova ◽  
Mateusz Mendel ◽  
...  

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Liyan Zhang ◽  
Xiurong Zhao ◽  
Guanghua Sun ◽  
Jaroslaw Aronowski

Background: After intracerebral hemorrhage (ICH), the red blood cells (RBC) and their hemolytic products within brain hematoma trigger adverse biochemical events, leading to secondary brain injury and neurological deficits. Thus, efficient removal of hematoma components is essential for achieving inflammation resolution and functional recovery. The inducible heme-oxygenase (HO-1) is a key rate-limiting enzyme that catabolizes heme into iron, CO, and biliverdin. The present study investigated the role of HO-1 in microglia/macrophages (MΦ)-mediated phagocytosis of RBC; and also assessed the spatial and temporal expression of HO-1 in ICH-affected brain, as well as its possible role in the clearance of hematoma components following ICH modeled in rodents. Methods and Results: First, we employed the rat brain MΦ. Upon exposing to RBC, MΦ phagocytize RBC; and HO-1 was induced during this process. Co-incubating tin-protoporphyrin IX (SnPP, a competitive HO-1 inhibitor) with RBC significantly delayed RBC internalization by MΦ. Removal of SnPP from the culture medium led to a rapid recovery of MΦ’s phagocytic function, suggesting that SnPP-induced inhibition is a reversible process. Subjecting neuron-microglia co-cultures to RBC plus sublethal dose of oxygen-deprivation (an ICH-like insult) triggered neuronal injury, as assessed using neurofilament degradation assay and loss of NeuN-positive cells; and addition of SnPP further aggravated the neuronal injury. Additional studies showed that after ICH, HO-1 is up-regulated in hematoma-affected rat brain tissues starting from 6h, reaching the maximum level at 3-7days, and persisting for at least 10 days after ICH. Double immunohistochemistry of HO-1 and brain cell markers shows that the most HO-1-positive cells are Iba1-positive MΦ. Administration of SnPP for 7 days, (7.5 mg/kg, ip, twice a day) delayed hematoma clearance by 27.8% and significantly impaired the functional recovery, as measured 7 days after ICH. Histological analyses showed that there are more TUNEL-positive neurons in the hematoma-affected brain tissue in SnPP-treated mouse brains. Conclusion: Our study suggests that HO-1 is essential for phagocytosis of RBC by MΦ, which is critical for endogenous clearance of hematoma after ICH.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4272-4272
Author(s):  
Mateusz Adamiak ◽  
Joseph B Moore IV ◽  
John Zhao ◽  
Ahmed Abdelbaset-Ismail ◽  
Marcin Wysoczynski ◽  
...  

Abstract Background . Heme oxygenase 1 (HO-1) is an inducible stress-response enzyme that not only catalyzes the degradation of heme (e.g., released from erythrocytes) but also has an important function in various physiological and pathophysiological states associated with cellular stress, such as ischemic/reperfusion injury. HO-1 has a well-documented anti-inflammatory potential and inhibits complement cascade (ComC)-mediated inflammatory responses. Moreover, HO-1 has been reported to have a negative effect on adhesion and migration of neutrophils in acute inflammation in a model of peritonitis. Radiation chimeras created after transplantation with HSPCs having a mutation in one of the alleles of HO-1 engrafted much faster; however, a persistent decrease in HO-1 activity in these animals resulted in their enhanced sensitivity to stress and susceptibility to irradiation (Blood 2008, 112, 4494-4502). Moreover, we recently demonstrated that HO-1-deficient HSPCs show enhanced in vitro migration up an SDF-1 gradient (Stem Cell Rev & Rep. 2015, 11, 110-118). Hypothesis. Based on these findings, we hypothesized that transient inhibition of HO-1 by non-toxic, small-molecule inhibitors would enhance in vivo migration of HSPCs to bone marrow (BM)-derived chemoattractants and thus would facilitate their homing and accelerate hematopoietic recovery Materials and Methods . To address this issue, we first generated several human hematopoietic cell lines in which HO-1 was upregulated or downregulated. We also exposed murine and human BM-derived cells to small-molecule inhibitors or activators of HO-1 and performed dose and timing toxicity studies. Next, murine BM mononuclear cells (MNCs) and human umbilical cord blood (UCB) MNCs were exposed to the small-molecule HO-1 inhibitor Sn(IV) protoporphyrin IX dichloride (SnPP) and tested for their chemotactic response in Transwell migration assays to all currently known HSPC chemoattractants, including stromal-derived factor 1 (SDF-1), sphingosine-1-phosphate (S1P), ceramide-1-phosphate (C1P), and the extracellular nucleotides ATP and UTP. For in vivo assays, lethally irradiated mice were transplanted with BM MNCs exposed or not exposed to SnPP, and in recipient animals we evaluated i) the number of day-12 colony-forming units in spleen (CFU-S) and colony-forming units for granulocyte/macrophage (CFU-GM) progenitors in BM and ii) the kinetics of peripheral blood (PB) count recovery by measuring the number of leucocytes, lymphocytes, and platelets. We also performed competitive repopulation studies with a limited number of transplanted BM MNCs using the CD45.1 and CD45.2 congenic mouse models. Results and Conclusions . We demonstrate here that HO-1 is a negative regulator of HSPC migration, and thus, by transiently inhibiting its activity in HSPCs with the non-toxic small-molecule inhibitor (SnPP), it is possible to accelerate homing and subsequent engraftment of HSPCs. We propose that this simple and inexpensive strategy could be employed in the clinical setting to improve seeding efficiency of transplanted HSPCs and their engraftment, particularly in those situations in which the number of HSPCs available for transplant is limited (e.g., from UCB or grafts harvested from poor mobilizers). Disclosures No relevant conflicts of interest to declare.


2006 ◽  
Vol 290 (4) ◽  
pp. C1092-C1099 ◽  
Author(s):  
Hadil Abuarqoub ◽  
Roberta Foresti ◽  
Colin J. Green ◽  
Roberto Motterlini

Chalcones are a group of plant-derived polyphenolic compounds that belong to the flavonoids family, and possess a wide variety of cytoprotective and modulatory functions. Chalcones exert their cytoprotective actions via activation of specific transcriptional factors and upregulation of endogenous defensive pathways, such as phase II enzymes and the stress protein heme oxygenase-1 (HO-1). In this study, we investigated the anti-inflammatory action of 2′-hydroxychalcone (2-HC) in a model of lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages and examined the role of HO-1 in this process. Our results demonstrate that 2-HC potently induces HO-1 expression and markedly reduces LPS-mediated nitrite and TNF-α production. These effects are accompanied by inhibition of inducible nitric oxide synthase protein expression and abolished by blockade of heme oxygenase activity with either tin protoporphyrin IX or HO-1 small interfering RNA. By using a pharmacological approach and siRNA technology, we also found that phosphatidylinositol 3-kinase is a major cellular mediator in 2-HC-induced HO-1 expression. These findings strongly suggest that 2-HC exerts anti-inflammatory actions via activation of the HO-1 pathway and help to elucidate the mechanisms underlying the potential therapeutic value of chalcones.


Author(s):  
Yuankun Ma ◽  
Liangliang Jia ◽  
Yidong Wang ◽  
Yongli Ji ◽  
Jian Chen ◽  
...  

Objective: Macrophage-mediated inflammatory response is closely associated with the neovascularization process following hindlimb ischemia. We previously demonstrated that HO-1 (heme oxygenase-1) in macrophages evoked proinflammatory reactions and tissue damage. Here, we evaluated the role played by macrophage-derived HO-1 and elucidated its underlying molecular mechanisms in perfusion recovery after hindlimb ischemia. Approach and Results: We found significant upregulation of HO-1 in mouse ischemic muscles after hindlimb ischemia surgery and with most of this expression occurring in infiltrated macrophages. Myeloid conditional HO-1-deficient mice exhibited higher perfusion recovery, evidenced by restored blood flow, motor function and attenuated tissue damage as well as increased capillary density in the gastrocnemius muscles after hindlimb ischemia, relative to littermate controls. This protective effect was accompanied by reduced nod-like receptor family, NLRP3 (pyrin domain containing 3) inflammasome activation in the infiltrated macrophages without the alteration of macrophage infiltration and polarization. Moreover, suppressing inflammasome activation with NLRP3 inhibitor MCC950 improved blood flow and capillary density in wild-type mice compared with untreated mice. Mechanistically, suppressing HO-1 abolished TNF (tumor necrosis factor)-α-induced NLRP3 protein rather than mRNA expression in bone marrow–derived macrophages, indicating that HO-1 mediated post-transcriptional regulation of NLRP3. Furthermore, HO-1 inhibition promoted autolysosome-dependent degradation of NLRP3 in bone marrow–derived macrophages. Matrigel tube formation assay revealed that HO-1 deletion abrogated the antiangiogenic effect of inflammasome-activated macrophages. Conclusions: Taken together, these findings indicate that macrophage HO-1 deficiency promotes perfusion recovery after hindlimb ischemia by accelerating autolysosomal degradation of NLRP3. The underlying mechanism of action is a potential target for therapeutic angiogenesis in ischemic diseases.


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