scholarly journals Less Airway Inflammation and Goblet Cell Metaplasia in an IL-33-Induced Asthma Model of Leptin-Deficient Obese Mice

2020 ◽  
Author(s):  
Atsushi Kurokawa ◽  
Mitsuko Kondo ◽  
Ken Arimura ◽  
Shigeru Ashino ◽  
Etsuko Tagaya

Abstract BackgroundAsthma with obesity is a phenotype of severe asthma. Leptin exerts an immunomodulatory effect and its level is increased in obesity. IL-33 is associated with innate immunity and induces type 2 inflammation, and is present in adipose tissue. However, the role of IL-33 and leptin in obesity-associated asthma is not fully understood. We examined the effect of IL-33 on eosinophilic inflammation, goblet cell metaplasia, and airway responsiveness in leptin-deficient obese (ob/ob) and wild-type mice, and examined the effect of exogenous leptin pretreatment. MethodsIn ob/ob and wild-type mice, IL-33 was instilled intranasally on three consecutive days. In part of the animals, leptin was injected intraperitoneally prior to IL-33 treatment. The mice were challenged with methacholine and resistance of the respiratory system (Rrs) was measured using the forced oscillation technique. Cell differentiation, IL-5, IL-13, eotaxin, KC in bronchoalveolar lavage fluid (BALF), and histology of the lung were analyzed. For the in vitro study, NCI-H292 cells were stimulated with IL-33 in the presence or absence of leptin, and MUC5AC levels were measured by ELISA. ResultsOb/ob mice showed greater baseline Rrs than wild-type mice. IL-33 and IL-33 with leptin did not enhance Rrs challenged with methacholine compared to non-treatment in ob/ob mice, whereas IL-33 with leptin enhanced Rrs in wild-type mice. Ob/ob mice showed less IL-33-induced eosinophil numbers, IL-5, IL-13, eotaxin, and KC levels in BALF and eosinophilic infiltration around bronchi and goblet cell metaplasia than wild-type mice, but leptin pretreatment attenuated these changes in ob/ob mice. MUC5AC levels were increased by co-stimulation with IL-33 and leptin in vitro . ConclusionsLeptin plays an important role in IL-33-induced inflammation and goblet cell metaplasia in the airway, but obesity per se increases airway hyperresponsiveness independent of inflammation. These results explain some aspects of the pathogenesis of obesity-related asthma.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Atsushi Kurokawa ◽  
Mitsuko Kondo ◽  
Ken Arimura ◽  
Shigeru Ashino ◽  
Etsuko Tagaya

Abstract Background Obesity-associated asthma is a phenotype of severe asthma. Late-onset, non-eosinophilic and female-dominant phenotype is highly symptomatic and difficult to treat. Leptin, an adipokine, exerts an immunomodulatory effect. IL-33 associated with innate immunity induces type 2 inflammation and is present in adipose tissue. The purpose of this study was to elucidate the pathogenesis of obesity-associated asthma by focusing on the interaction between leptin and IL-33. Methods In leptin-deficient obese (ob/ob) and wild-type mice, IL-33 was instilled intranasally on three consecutive days. In part of the mice, leptin was injected intraperitoneally prior to IL-33 treatment. The mice were challenged with methacholine, and airway hyperresponsiveness (AHR) was assessed by resistance (Rrs) and elastance (Ers) of the respiratory system using the forced oscillation technique. Cell differentiation, IL-5, IL-13, eotaxin, keratinocyte-derived chemokine (KC) in bronchoalveolar lavage fluid (BALF) and histology of the lung were analyzed. For the in vitro study, NCI-H292 cells were stimulated with IL-33 in the presence or absence of leptin. Mucin-5AC (MUC5AC) levels were measured using an enzyme-linked immunosorbent assay. Results Ob/ob mice showed greater Rrs and Ers than wild-type mice. IL-33 with leptin, but not IL-33 alone, enhanced Ers rather than Rrs challenged with methacholine in ob/ob mice, whereas it enhanced Rrs alone in wild-type mice. IL-33-induced eosinophil numbers, cytokine levels in BALF, eosinophilic infiltration around the bronchi, and goblet cell metaplasia were less in ob/ob mice than in wild-type mice. However, leptin pretreatment attenuated these changes in ob/ob mice. MUC5AC levels were increased by co-stimulation with IL-33 and leptin in vitro. Conclusions Ob/ob mice show innate AHR. IL-33 with leptin, but not IL-33 alone, induces airway inflammation and goblet cell metaplasia and enhances AHR involving peripheral airway closure. This is presumably accelerated by mucus in ob/ob mice. These results may explain some aspects of the pathogenesis of obesity-associated asthma.


2007 ◽  
Vol 204 (4) ◽  
pp. 865-877 ◽  
Author(s):  
William R. Henderson ◽  
Emil Y. Chi ◽  
James G. Bollinger ◽  
Ying-tzang Tien ◽  
Xin Ye ◽  
...  

Arachidonic acid metabolites, the eicosanoids, are key mediators of allergen-induced airway inflammation and remodeling in asthma. The availability of free arachidonate in cells for subsequent eicosanoid biosynthesis is controlled by phospholipase A2s (PLA2s), most notably cytosolic PLA2-α. 10 secreted PLA2s (sPLA2s) have also been identified, but their function in eicosanoid generation is poorly understood. We investigated the role of group X sPLA2 (sPLA2-X), the sPLA2 with the highest in vitro cellular phospholipolysis activity, in acute and chronic mouse asthma models in vivo. The lungs of sPLA2-X−/− mice, compared with those of sPLA2-X+/+ littermates, had significant reduction in ovalbumin-induced infiltration by CD4+ and CD8+ T cells and eosinophils, goblet cell metaplasia, smooth muscle cell layer thickening, subepithelial fibrosis, and levels of T helper type 2 cell cytokines and eicosanoids. These data direct attention to sPLA2-X as a novel therapeutic target for asthma.


2012 ◽  
Vol 113 (9) ◽  
pp. 1476-1485 ◽  
Author(s):  
Ming Zhu ◽  
Alison S. Williams ◽  
Lucas Chen ◽  
Allison P. Wurmbrand ◽  
Erin S. Williams ◽  
...  

The purpose of this study was to examine the role of tumor necrosis factor receptor 1 (TNFR1) in the airway hyperresponsiveness characteristic of obese mice. Airway responsiveness to intravenous methacholine was measured using the forced oscillation technique in obese Cpe fat mice that were either sufficient or genetically deficient in TNFR1 ( Cpe fat and Cpe fat/TNFR1−/− mice) and in lean mice that were either sufficient or genetically deficient in TNFR1 [wild-type (WT) and TNFR1−/− mice]. Compared with lean WT mice, Cpe fat mice exhibited airway hyperresponsiveness. Airway hyperresponsives was also greater in Cpe fat/TNFR1−/− than in Cpe fat mice. Compared with WT mice, Cpe fat mice had increases in bronchoalveolar lavage fluid concentrations of several inflammatory moieties including eotaxin, IL-9, IP-10, KC, MIG, and VEGF. These factors were also significantly elevated in Cpe fat/TNFR1−/− vs. TNFR1−/− mice. Additional moieties including IL-13 were also elevated in Cpe fat/TNFR1−/− vs. TNFR1−/− mice but not in Cpe fat vs. WT mice. IL-17A mRNA expression was greater in Cpe fat/TNFR1−/− vs. Cpe fat mice and in TNFR1−/− vs. WT mice. Analysis of serum indicated that obesity resulted in systemic as well as pulmonary inflammation, but TNFR1 deficiency had little effect on this systemic inflammation. Our results indicate that TNFR1 is protective against the airway hyperresponsiveness associated with obesity and suggest that effects on pulmonary inflammation may be contributing to this protection.


2008 ◽  
Vol 294 (2) ◽  
pp. L368-L377 ◽  
Author(s):  
Theo J. Moraes ◽  
Raiza Martin ◽  
Jonathan D. Plumb ◽  
Eric Vachon ◽  
Cheryl M. Cameron ◽  
...  

Proteinases can influence lung inflammation by various mechanisms, including via cleavage and activation of protease-activated receptors (PAR) such as PAR2. In addition, proteinases such as neutrophil and/or Pseudomonas-derived elastase can disarm PAR2 resulting in loss of PAR2 signaling. Currently, the role of PAR2 in host defense against bacterial infection is not known. Using a murine model of acute Pseudomonas aeruginosa pneumonia, we examined differences in the pulmonary inflammatory response between wild-type and PAR2−/−mice. Compared with wild-type mice, PAR2−/−mice displayed more severe lung inflammation and injury in response to P. aeruginosa infection as indicated by higher bronchoalveolar lavage fluid neutrophil numbers, protein concentration, and TNF-α levels. By contrast, IFN-γ levels were markedly reduced in PAR2−/−compared with wild-type mice. Importantly, clearance of P. aeruginosa was diminished in PAR2−/−mice. In vitro testing revealed that PAR2−/−neutrophils killed significantly less bacteria than wild-type murine neutrophils. Further, both neutrophils and macrophages from PAR2−/−mice displayed significantly reduced phagocytic efficiency compared with wild-type phagocytes. Stimulation of PAR2 on macrophages using a PAR2-activating peptide resulted in enhanced phagocytosis directly implicating PAR2 signaling in the phagocytic process. We conclude that genetic deletion of PAR2 is associated with decreased clearance of P. aeruginosa. Our data suggest that a deficiency in IFN-γ production and impaired bacterial phagocytosis are two potential mechanisms responsible for this defect.


Endocrinology ◽  
2008 ◽  
Vol 149 (8) ◽  
pp. 4080-4085 ◽  
Author(s):  
Maria Pini ◽  
Melissa E. Gove ◽  
Joseph A. Sennello ◽  
Jantine W. P. M. van Baal ◽  
Lawrence Chan ◽  
...  

Adipokines, cytokines mainly produced by adipocytes, are active participants in the regulation of inflammation. Administration of zymosan (ZY) was used to investigate the regulation and role of adipokines during peritonitis in mice. Injection of ZY led to a significant increase in leptin levels in both serum and peritoneal lavage fluid, whereas a differential trend in local vs. systemic levels was observed for both resistin and adiponectin. The role of leptin in ZY-induced peritonitis was investigated using leptin-deficient ob/ob mice, with and without reconstitution with exogenous leptin. Leptin deficiency was associated with delayed resolution of peritoneal inflammation induced by ZY, because ob/ob mice had a more pronounced cellular infiltrate in the peritoneum as well as higher and prolonged local and systemic levels of IL-6, TNFα, IL-10, and chemokine (C-X-C motif) ligand 2 compared with wild-type mice. Reconstitution with exogenous leptin exacerbated the inflammatory infiltrate and systemic IL-6 levels in ob/ob mice while inhibiting production of TNFα, IL-10, and chemokine (C-X-C motif) ligand 2. In contrast with the important role of leptin in regulating each aspect of ZY-induced peritonitis, adiponectin deficiency was associated only with a decreased inflammatory infiltrate, without affecting cytokine levels. These findings point to a complex role for adipokines in ZY-induced peritonitis and further emphasize the interplay between obesity and inflammation.


2021 ◽  
Vol 11 (15) ◽  
pp. 6865
Author(s):  
Eun Seon Lee ◽  
Joung Hun Park ◽  
Seong Dong Wi ◽  
Ho Byoung Chae ◽  
Seol Ki Paeng ◽  
...  

The thioredoxin-h (Trx-h) family of Arabidopsis thaliana comprises cytosolic disulfide reductases. However, the physiological function of Trx-h2, which contains an additional 19 amino acids at its N-terminus, remains unclear. In this study, we investigated the molecular function of Trx-h2 both in vitro and in vivo and found that Arabidopsis Trx-h2 overexpression (Trx-h2OE) lines showed significantly longer roots than wild-type plants under cold stress. Therefore, we further investigated the role of Trx-h2 under cold stress. Our results revealed that Trx-h2 functions as an RNA chaperone by melting misfolded and non-functional RNAs, and by facilitating their correct folding into active forms with native conformation. We showed that Trx-h2 binds to and efficiently melts nucleic acids (ssDNA, dsDNA, and RNA), and facilitates the export of mRNAs from the nucleus to the cytoplasm under cold stress. Moreover, overexpression of Trx-h2 increased the survival rate of the cold-sensitive E. coli BX04 cells under low temperature. Thus, our data show that Trx-h2 performs function as an RNA chaperone under cold stress, thus increasing plant cold tolerance.


2021 ◽  
Vol 165 ◽  
pp. 39
Author(s):  
Francesca Lombardi ◽  
Silvano Santini ◽  
Paola Palumbo ◽  
Valeria Cordone ◽  
Virginio Bignotti ◽  
...  

2021 ◽  
Vol 22 (4) ◽  
pp. 1825
Author(s):  
Li Hao ◽  
Aaron J. Marshall ◽  
Lixin Liu

Bam32 (B cell adaptor molecule of 32 kDa) functions in the immune responses of various leukocytes. However, the role of neutrophil Bam32 in inflammation is entirely unknown. Here, we determined the role of Bam32 in chemokine CXCL2-induced neutrophil chemotaxis in three mouse models of neutrophil recruitment. By using intravital microscopy in the mouse cremaster muscle, we found that transmigrated neutrophil number, neutrophil chemotaxis velocity, and total neutrophil chemotaxis distance were increased in Bam32−/− mice when compared with wild-type (WT) mice. In CXCL2-induced mouse peritonitis, the total emigrated neutrophils were increased in Bam32−/− mice at 2 but not 4 h. The CXCL2-induced chemotaxis distance and migration velocity of isolated Bam32−/− neutrophils in vitro were increased. We examined the activation of small GTPases Rac1, Rac2, and Rap1; the levels of phospho-Akt2 and total Akt2; and their crosstalk with Bam32 in neutrophils. The deficiency of Bam32 suppressed Rap1 activation without changing the activation of Rac1 and Rac2. The pharmacological inhibition of Rap1 by geranylgeranyltransferase I inhibitor (GGTI298) increased WT neutrophil chemotaxis. In addition, the deficiency of Bam32, as well as the inhibition of Rap1 activation, increased the levels of CXCL2-induced Akt1/2 phosphorylation at Thr308/309 in neutrophils. The inhibition of Akt by SH-5 attenuated CXCL2-induced adhesion and emigration in Bam32−/− mice. Together, our results reveal that Bam32 has a suppressive role in chemokine-induced neutrophil chemotaxis by regulating Rap1 activation and that this role of Bam32 in chemokine-induced neutrophil recruitment relies on the activation of PI3K effector Akt.


2021 ◽  
pp. 019459982110147
Author(s):  
Ioan A. Lina ◽  
Alexandra Berges ◽  
Rafael Ospino ◽  
Ruth J. Davis ◽  
Kevin M. Motz ◽  
...  

Objective Iatrogenic laryngotracheal stenosis (iLTS) is the pathologic narrowing of the glottis, subglottis, and/or trachea secondary to intubation or tracheostomy related injury. Patients with type 2 diabetes mellitus (T2DM) are more likely to develop iLTS. To date, the metabolomics and phenotypic expression of cell markers in fibroblasts derived from patients with T2DM and iLTS are largely unknown. Study Design Controlled in vitro cohort study. Setting Tertiary referral center (2017-2020). Methods This in vitro study assessed samples from 6 patients with iLTS who underwent surgery at a single institution. Fibroblasts were isolated from biopsy specimens of laryngotracheal scar and normal-appearing trachea and compared with controls obtained from the trachea of rapid autopsy specimens. Patients with iLTS were subcategorized into those with and without T2DM. Metabolic substrates were identified by mass spectrometry, and cell protein expression was measured by flow cytometry. Results T2DM iLTS-scar fibroblasts had a metabolically distinct profile and clustered tightly on a Pearson correlation heat map as compared with non-T2DM iLTS-scar fibroblasts. Levels of itaconate were elevated in T2DM iLTS-scar fibroblasts. Flow cytometry demonstrated that T2DM iLTS-scar fibroblasts were associated with higher CD90 expression (Thy-1; mean, 95%) when compared with non-T2DM iLTS-scar (mean, 83.6%; P = .0109) or normal tracheal fibroblasts (mean, 81.1%; P = .0042). Conclusions Scar-derived fibroblasts from patients with T2DM and iLTS have a metabolically distinct profile. These fibroblasts are characterized by an increase in itaconate, a metabolite related to immune-induced scar remodeling, and can be identified by elevated expression of CD90 (Thy-1) in vitro.


Sign in / Sign up

Export Citation Format

Share Document