scholarly journals Pivotal role of IL-6 in the hyperinflammatory responses to subacute ozone in adiponectin-deficient mice

2014 ◽  
Vol 306 (6) ◽  
pp. L508-L520 ◽  
Author(s):  
David I. Kasahara ◽  
Hye Y. Kim ◽  
Joel A. Mathews ◽  
Norah G. Verbout ◽  
Alison S. Williams ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Γδ T Cells ◽  
Pivotal Role ◽  
Ozone Exposure ◽  
Granulocyte Colony Stimulating Factor ◽  
Wild Type ◽  
Neutrophilic Inflammation ◽  
Stimulating Factor ◽  
Deficient Mice

Adiponectin is an adipose-derived hormone with anti-inflammatory activity. Following subacute ozone exposure (0.3 ppm for 24–72 h), neutrophilic inflammation and IL-6 are augmented in adiponectin-deficient ( Adipo−/−) mice. The IL-17/granulocyte colony-stimulating factor (G-CSF) axis is required for this increased neutrophilia. We hypothesized that elevated IL-6 in Adipo−/−mice contributes to their augmented responses to ozone via effects on IL-17A expression. Therefore, we generated mice deficient in both adiponectin and IL-6 ( Adipo−/−/IL-6−/−) and exposed them to ozone or air. In ozone-exposed mice, bronchoalveolar lavage (BAL) neutrophils, IL-6, and G-CSF, and pulmonary Il17a mRNA expression were greater in Adipo−/−vs. wild-type mice, but reduced in Adipo−/−/IL-6−/−vs. Adipo−/−mice. IL-17A+F4/80+cells and IL-17A+γδ T cells were also reduced in Adipo−/−/IL-6−/−vs. Adipo−/−mice exposed to ozone. Only BAL neutrophils were reduced in IL-6−/−vs. wild-type mice. In wild-type mice, IL-6 was expressed in Gr-1+F4/80−CD11c−cells, whereas in Adipo−/−mice F4/80+CD11c+cells also expressed IL-6, suggesting that IL-6 is regulated by adiponectin in these alveolar macrophages. Transcriptomic analysis identified serum amyloid A3 ( Saa3), which promotes IL-17A expression, as the gene most differentially augmented by ozone in Adipo−/−vs. wild-type mice. After ozone, Saa3 mRNA expression was markedly greater in Adipo−/−vs. wild-type mice but reduced in Adipo−/−/IL-6−/−vs. Adipo−/−mice. In conclusion, our data support a pivotal role of IL-6 in the hyperinflammatory condition observed in Adipo−/−mice after ozone exposure and suggest that this role of IL-6 involves its ability to induce Saa3, IL-17A, and G-CSF.

scholarly journals Pulmonary responses to subacute ozone exposure in obese vs. lean mice

2009 ◽  
Vol 107 (5) ◽  
pp. 1445-1452 ◽  
Author(s):  
Stephanie A. Shore ◽  
Jason E. Lang ◽  
David I. Kasahara ◽  
Frank L. Lu ◽  
Norah G. Verbout ◽  
...  
Keyword(s):  
No Reduction ◽  
Neutrophil Recruitment ◽  
Ozone Exposure ◽  
Pulmonary Injury ◽  
Obese Mice ◽  
Wild Type ◽  
Neutrophilic Inflammation ◽  
Fat Diets ◽  
Deficient Mice

The purpose of this study was to determine whether obesity affects pulmonary responses following a 3-day ozone exposure. Obese db/ db and lean wild-type mice were exposed to ozone (0.3 ppm) for 72 h. In wild-type mice, ozone exposure caused pulmonary injury and inflammation, and these events were associated with reduced pulmonary compliance. In db/ db mice, ozone-induced neutrophil recruitment to the lung was reduced and no reduction in compliance was observed. Similar results were obtained in obese Cpe fat mice, indicating that loss of leptin signaling in db/ db mice does not account for these obesity-related changes. To examine the role of interleukin (IL)-6 in this obesity-related difference in ozone responsiveness, wild-type and IL-6-deficient mice were raised on 10% or 60% fat diets. Compared with 10% fat-fed mice, wild-type 60% fat-fed mice were obese and had reduced neutrophil recruitment following ozone. IL-6 deficiency reduced ozone-induced neutrophil recruitment in 10% fat-fed mice. In contrast, in obese mice, no effect of IL-6 deficiency on neutrophil recruitment was observed. Obesity-related differences in the effect of ozone on compliance were observed in both wild-type and IL-6-deficient mice. Obesity-related differences in serum IL-6 were observed and may account for obesity-related differences in the effect of IL-6 deficiency on neutrophil recruitment. In summary, the neutrophilic inflammation induced by prolonged low level ozone exposure was attenuated in obese mice and appeared to result from an absence of IL-6-dependent neutrophil recruitment in the obese mice.

scholarly journals Interleukin-6 and the Granulocyte Colony-Stimulating Factor Receptor Are Major Independent Regulators of Granulopoiesis In Vivo But Are Not Required for Lineage Commitment or Terminal Differentiation

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2583-2590 ◽  
Author(s):  
Fulu Liu ◽  
Jennifer Poursine-Laurent ◽  
Huai Yang Wu ◽  
Daniel C. Link
Keyword(s):  
Interleukin 6 ◽  
Terminal Differentiation ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Normal Numbers ◽  
Stimulating Factor ◽  
Deficient Mice ◽  
Additional Loss

Multiple hematopoietic cytokines can stimulate granulopoiesis; however, their relative importance in vivo and mechanisms of action remain unclear. We recently reported that granulocyte colony-stimulating factor receptor (G-CSFR)-deficient mice have a severe quantitative defect in granulopoiesis despite which phenotypically normal neutrophils were still detected. These results confirmed a role for the G-CSFR as a major regulator of granulopoiesis in vivo, but also indicated that G-CSFR independent mechanisms of granulopoiesis must exist. To explore the role of interleukin-6 (IL-6) in granulopoiesis, we generated IL-6 × G-CSFR doubly deficient mice. The additional loss of IL-6 significantly worsened the neutropenia present in young adult G-CSFR–deficient mice; moreover, exogenous IL-6 stimulated granulopoiesis in vivo in the absence of G-CSFR signals. Near normal numbers of myeloid progenitors were detected in the bone marrow of IL-6 × G-CSFR–deficient mice and their ability to terminally differentiate into mature neutrophils was observed. These results indicate that IL-6 is an independent regulator of granulopoiesis in vivo and show that neither G-CSFR or IL-6 signals are required for the commitment of multipotential progenitors to the myeloid lineage or for their terminal differentiation.

scholarly journals Proliferation Signaling and Activation of Shc, p21Ras, and Myc Via Tyrosine 764 of Human Granulocyte Colony-Stimulating Factor Receptor

Blood ◽  
1998 ◽  
Vol 91 (6) ◽  
pp. 1924-1933 ◽  
Author(s):  
John P. de Koning ◽  
Amrita A. Soede-Bobok ◽  
Anita M. Schelen ◽  
Louise Smith ◽  
Daphne van Leeuwen ◽  
...  
Keyword(s):  
Distal Region ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Wild Type ◽  
Tyrosine Residues ◽  
Signaling Mechanisms ◽  
Fold Reduction ◽  
Multiple Signaling ◽  
Stimulating Factor

The membrane-distal region of the cytoplasmic domain of human granulocyte colony-stimulating factor receptor (G-CSF-R) contains four conserved tyrosine residues: Y704, Y729, Y744, and Y764. Three of these (Y729, Y744, and Y764) are located in the C-terminal part of G-CSF-R, previously shown to be essential for induction of neutrophilic differentiation. To determine the role of the tyrosines in G-CSF–mediated responses, we constructed tyrosine-to-phenylalanine (Y-to-F) substitution mutants and expressed these in a differentiation competent subclone of 32D cells that lacks endogenous G-CSF-R. We show that all tyrosines can be substituted essentially without affecting the differentiation signaling properties of G-CSF-R. However, substitution of one specific tyrosine, ie, Y764, markedly influenced proliferation signaling as well as the timing of differentiation. 32D cells expressing wild-type (WT) G-CSF-R (or mutants Y704F, Y729F, or Y744F) proliferated in G-CSF–containing cultures until day 8 and then developed into mature neutrophils. In contrast, 32D/Y764F cells arrested in the G1 phase of the cell cycle within 24 hours and showed complete neutrophilic differentiation after 3 days of culture. This resulted in an average 30-fold reduction of neutrophil production as compared with the 32D/WT controls. Importantly, G-CSF–mediated activation of Shc, p21Ras and the induction of c-myc were severely reduced by substitution of Y764. These findings indicate that Y764 of G-CSF-R is crucial for maintaining the proliferation/differentiation balance during G-CSF–driven neutrophil development and suggest a role for multiple signaling mechanisms in maintaining this balance.

scholarly journals Proliferation Signaling and Activation of Shc, p21Ras, and Myc Via Tyrosine 764 of Human Granulocyte Colony-Stimulating Factor Receptor

Blood ◽  
1998 ◽  
Vol 91 (6) ◽  
pp. 1924-1933 ◽  
Author(s):  
John P. de Koning ◽  
Amrita A. Soede-Bobok ◽  
Anita M. Schelen ◽  
Louise Smith ◽  
Daphne van Leeuwen ◽  
...  
Keyword(s):  
Distal Region ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Wild Type ◽  
Tyrosine Residues ◽  
Signaling Mechanisms ◽  
Fold Reduction ◽  
Multiple Signaling ◽  
Stimulating Factor

Abstract The membrane-distal region of the cytoplasmic domain of human granulocyte colony-stimulating factor receptor (G-CSF-R) contains four conserved tyrosine residues: Y704, Y729, Y744, and Y764. Three of these (Y729, Y744, and Y764) are located in the C-terminal part of G-CSF-R, previously shown to be essential for induction of neutrophilic differentiation. To determine the role of the tyrosines in G-CSF–mediated responses, we constructed tyrosine-to-phenylalanine (Y-to-F) substitution mutants and expressed these in a differentiation competent subclone of 32D cells that lacks endogenous G-CSF-R. We show that all tyrosines can be substituted essentially without affecting the differentiation signaling properties of G-CSF-R. However, substitution of one specific tyrosine, ie, Y764, markedly influenced proliferation signaling as well as the timing of differentiation. 32D cells expressing wild-type (WT) G-CSF-R (or mutants Y704F, Y729F, or Y744F) proliferated in G-CSF–containing cultures until day 8 and then developed into mature neutrophils. In contrast, 32D/Y764F cells arrested in the G1 phase of the cell cycle within 24 hours and showed complete neutrophilic differentiation after 3 days of culture. This resulted in an average 30-fold reduction of neutrophil production as compared with the 32D/WT controls. Importantly, G-CSF–mediated activation of Shc, p21Ras and the induction of c-myc were severely reduced by substitution of Y764. These findings indicate that Y764 of G-CSF-R is crucial for maintaining the proliferation/differentiation balance during G-CSF–driven neutrophil development and suggest a role for multiple signaling mechanisms in maintaining this balance.

scholarly journals Lupus-like autoimmune disease caused by a lack of Xkr8, a caspase-dependent phospholipid scramblase

2018 ◽  
Vol 115 (9) ◽  
pp. 2132-2137 ◽  
Author(s):  
Mahiru Kawano ◽  
Shigekazu Nagata
Keyword(s):  
Autoimmune Disease ◽  
Apoptotic Cells ◽  
Dependent Manner ◽  
Granulocyte Colony Stimulating Factor ◽  
Wild Type ◽  
Phospholipid Scramblase ◽  
Complex Deposition ◽  
Stimulating Factor ◽  
Deficient Mice

Apoptotic cells expose phosphatidylserine (PtdSer) on their cell surface and are recognized by macrophages for clearance. Xkr8 is a scramblase that exposes PtdSer in a caspase-dependent manner. Here, we found that among the three Xkr members with caspase-dependent scramblase activity, mouse hematopoietic cells express only Xkr8. The PtdSer exposure of apoptotic thymocytes, splenocytes, and neutrophils was strongly reduced when Xkr8 was absent. While wild-type apoptotic lymphocytes and neutrophils were efficiently engulfed in vitro by phagocytes expressing Tim4 and MerTK, Xkr8-deficient apoptotic cells were hardly engulfed by these phagocytes. Accordingly, the number of apoptotic thymocytes in the thymus and neutrophils in the peritoneal cavity of the zymosan-treated mice was significantly increased in Xkr8-deficient mice. The percentage of CD62Llo senescent neutrophils was increased in the spleen of Xkr8-null mice, especially after the treatment with granulocyte colony-stimulating factor. Xkr8-null mice on an MRL background showed high levels of autoantibodies, splenomegaly with high levels of effector CD4 T cells, and glomerulonephritis development with immune-complex deposition at glomeruli. These results indicate that the Xkr8-mediated PtdSer exposure in apoptotic lymphocytes and aged neutrophils is essential for their clearance, and its defect activates the immune system, leading to lupus-like autoimmune disease.

“Emergency” granulopoiesis in G-CSF–deficient mice in response to Candida albicans infection

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3725-3733 ◽  
Author(s):  
Sunanda Basu ◽  
George Hodgson ◽  
Hui-Hua Zhang ◽  
Melissa Katz ◽  
Cathy Quilici ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Candida Albicans ◽  
Emergency Response ◽  
Emergency Situation ◽  
Wild Type ◽  
Gm Csf ◽  
Stimulating Factor ◽  
Physiologic Role ◽  
Deficient Mice

Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein believed to play an important role in regulating granulopoiesis both at steady state and during an “emergency” situation. Generation of G-CSF and G-CSF receptor–deficient mice by gene targeting has demonstrated unequivocally the importance of G-CSF in the regulation of baseline granulopoiesis. This study attempted to define the physiologic role of G-CSF during an emergency situation by challenging a cohort of wild-type and G-CSF–deficient mice with Candida albicans. Interestingly, after infection, G-CSF–deficient mice developed an absolute neutrophilia that was observed both in blood and bone marrow. In addition, 3 days after Candida infection increased numbers of granulocyte-macrophage (GM) and macrophage (M) progenitors were observed in the bone marrow of G-CSF–deficient mice. Of the cytokines surveyed, interleukin (IL)-6 levels in serum were elevated; interestingly, levels of IL-6 were higher and more sustained in G-CSF–deficient mice infected with C albicans than similarly infected wild-type mice. Despite the higher levels of serum IL-6, this cytokine is dispensable for the observed neutrophilia because candida-infected IL-6–deficient mice, or mice simultaneously deficient in G-CSF and IL-6, developed neutrophilia. Similarly, mice lacking both G-CSF and GM-CSF developed absolute neutrophilia and had elevated numbers of GM and M progenitors in the bone marrow; thus, G-CSF and GM-CSF are dispensable for promoting the emergency response to candidal infection.

“Emergency” granulopoiesis in G-CSF–deficient mice in response to Candida albicans infection

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3725-3733 ◽  
Author(s):  
Sunanda Basu ◽  
George Hodgson ◽  
Hui-Hua Zhang ◽  
Melissa Katz ◽  
Cathy Quilici ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Candida Albicans ◽  
Emergency Response ◽  
Emergency Situation ◽  
Wild Type ◽  
Gm Csf ◽  
Stimulating Factor ◽  
Physiologic Role ◽  
Deficient Mice

Abstract Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein believed to play an important role in regulating granulopoiesis both at steady state and during an “emergency” situation. Generation of G-CSF and G-CSF receptor–deficient mice by gene targeting has demonstrated unequivocally the importance of G-CSF in the regulation of baseline granulopoiesis. This study attempted to define the physiologic role of G-CSF during an emergency situation by challenging a cohort of wild-type and G-CSF–deficient mice with Candida albicans. Interestingly, after infection, G-CSF–deficient mice developed an absolute neutrophilia that was observed both in blood and bone marrow. In addition, 3 days after Candida infection increased numbers of granulocyte-macrophage (GM) and macrophage (M) progenitors were observed in the bone marrow of G-CSF–deficient mice. Of the cytokines surveyed, interleukin (IL)-6 levels in serum were elevated; interestingly, levels of IL-6 were higher and more sustained in G-CSF–deficient mice infected with C albicans than similarly infected wild-type mice. Despite the higher levels of serum IL-6, this cytokine is dispensable for the observed neutrophilia because candida-infected IL-6–deficient mice, or mice simultaneously deficient in G-CSF and IL-6, developed neutrophilia. Similarly, mice lacking both G-CSF and GM-CSF developed absolute neutrophilia and had elevated numbers of GM and M progenitors in the bone marrow; thus, G-CSF and GM-CSF are dispensable for promoting the emergency response to candidal infection.

scholarly journals Interleukin-6 and the Granulocyte Colony-Stimulating Factor Receptor Are Major Independent Regulators of Granulopoiesis In Vivo But Are Not Required for Lineage Commitment or Terminal Differentiation

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2583-2590 ◽  
Author(s):  
Fulu Liu ◽  
Jennifer Poursine-Laurent ◽  
Huai Yang Wu ◽  
Daniel C. Link
Keyword(s):  
Interleukin 6 ◽  
Terminal Differentiation ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Normal Numbers ◽  
Stimulating Factor ◽  
Deficient Mice ◽  
Additional Loss

Abstract Multiple hematopoietic cytokines can stimulate granulopoiesis; however, their relative importance in vivo and mechanisms of action remain unclear. We recently reported that granulocyte colony-stimulating factor receptor (G-CSFR)-deficient mice have a severe quantitative defect in granulopoiesis despite which phenotypically normal neutrophils were still detected. These results confirmed a role for the G-CSFR as a major regulator of granulopoiesis in vivo, but also indicated that G-CSFR independent mechanisms of granulopoiesis must exist. To explore the role of interleukin-6 (IL-6) in granulopoiesis, we generated IL-6 × G-CSFR doubly deficient mice. The additional loss of IL-6 significantly worsened the neutropenia present in young adult G-CSFR–deficient mice; moreover, exogenous IL-6 stimulated granulopoiesis in vivo in the absence of G-CSFR signals. Near normal numbers of myeloid progenitors were detected in the bone marrow of IL-6 × G-CSFR–deficient mice and their ability to terminally differentiate into mature neutrophils was observed. These results indicate that IL-6 is an independent regulator of granulopoiesis in vivo and show that neither G-CSFR or IL-6 signals are required for the commitment of multipotential progenitors to the myeloid lineage or for their terminal differentiation.

scholarly journals The Granulocyte Colony-Stimulating Factor Receptor Is Required for the Mobilization of Murine Hematopoietic Progenitors Into Peripheral Blood by Cyclophosphamide or Interleukin-8 But Not Flt-3 Ligand

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2522-2528 ◽  
Author(s):  
Fulu Liu ◽  
Jennifer Poursine-Laurent ◽  
Daniel C. Link
Keyword(s):  
Bone Marrow ◽  
Interleukin 8 ◽  
Cytotoxic Agents ◽  
Common Mechanism ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Wild Type ◽  
Stimulating Factor ◽  
Deficient Mice ◽  
Cyclophosphamide Administration

Hematopoietic progenitor cells (HPC) can be mobilized from the bone marrow into the peripheral circulation in response to a number of stimuli including hematopoietic growth factors, cytotoxic agents, and certain chemokines. Despite significant differences in their biological activities, these stimuli result in the mobilization of HPC with a similar phenotype, suggesting that a common mechanism for mobilization may exist. In this study, the role of granulocyte colony-stimulating factor (G-CSF) in progenitor mobilization was examined using G-CSF receptor (G-CSFR)–deficient mice. In contrast to wild-type mice, no increase in circulating colony-forming cells (CFU-C), CD34+ lineage− progenitors, or day 12 colony-forming unit-spleen progenitors (CFU-S) was detected in G-CSFR–deficient mice after cyclophosphamide administration. This defect was not due to a failure to regenerate HPC following cyclophosphamide administration as the number of CFU-C in the bone marrow of G-CSFR–deficient mice was increased relative to wild-type mice. Likewise, no increase in circulating CFU-C was detected in G-CSFR–deficient mice following interleukin-8 (IL-8) administration. In contrast, mobilization of HPC in response to flt-3 ligand was nearly normal. These results show that the G-CSFR is required for mobilization in response to cyclophosphamide or IL-8 but not flt-3 ligand and suggest that the G-CSFR may play an important and previously unexpected role in HPC migration.

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