Ovalbumin sensitization and challenge increases the number of lung cells possessing a mesenchymal stromal cell phenotype

Abstract Background Recent studies have indicated the presence of multipotent mesenchymal stromal cells (MSCs) in human lung diseases. Excess airway smooth muscle, myofibroblasts and activated fibroblasts have each been noted in asthma, suggesting that mesenchymal progenitor cells play a role in asthma pathogenesis. We therefore sought to determine whether MSCs are present in the lungs of ovalbumin (OVA)-sensitized and challenged mice, a model of allergic airways disease. Methods Balb/c mice were sensitized and challenged with PBS or OVA over a 25 day period. Flow cytometry as well as colony forming and differentiation potential were used to analyze the emergence of MSCs along with gene expression studies using immunochemical analyses, quantitative polymerase chain reaction (qPCR), and gene expression beadchips. Results A CD45-negative subset of cells expressed Stro-1, Sca-1, CD73 and CD105. Selection for these markers and negative selection against CD45 yielded a population of cells capable of adipogenic, osteogenic and chondrogenic differentiation. Lungs from OVA-treated mice demonstrated a greater average colony forming unit-fibroblast (CFU-F) than control mice. Sorted cells differed from unsorted lung adherent cells, exhibiting a pattern of gene expression nearly identical to bone marrow-derived sorted cells. Finally, cells isolated from the bronchoalveolar lavage of a human asthma patient showed identical patterns of cell surface markers and differentiation potential. Conclusions In summary, allergen sensitization and challenge is accompanied by an increase of MSCs resident in the lungs that may regulate inflammatory and fibrotic responses.http://deepblue.lib.umich.edu/bitstream/2027.42/78265/1/1465-9921-11-127.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78265/2/1465-9921-11-127.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/78265/3/1465-9921-11-127-S1.DOCPeer Reviewe

Connecting the Dots: A Rare Cause of Pulmonary Nodules in a 13-Year-Old Boy

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140177/1/ped.2014.0392.pd

The Perceived Size and Shape of Objects in Peripheral Vision

Little is known about how we perceive the size and shape of objects in far peripheral vision. Observations made during an artistic study of visual space suggest that objects appear smaller and compressed in the periphery compared with central vision. To test this, we conducted three experiments. In Experiment 1, we asked participants to draw how a set of peripheral discs appeared when viewed peripherally without time or eye movement constraints. In Experiment 2, we used the method of constant stimuli to measure when a briefly presented peripheral stimulus appeared bigger or smaller compared with a central fixated one. In Experiment 3, we measured how accurate participants were in discriminating shapes presented briefly in the periphery. In Experiment 1, the peripheral discs were reported as appearing significantly smaller than the central disc, and as having an elliptical or polygonal contour. In Experiment 2, participants judged the size of peripheral discs as being significantly smaller when compared with the central disc across most of the peripheral field, and in Experiment 3, participants were quite accurate in reporting the shape of the peripheral object, except in the far periphery. Our results show that objects in the visual periphery are perceived as diminished in size when presented for long and brief exposures, suggesting diminution is an intrinsic feature of the structure of the visual space. Shape distortions, however, are reported only with longer exposures

A Comprehensive Pediatric Asthma Management Program Reduces Emergency Department Visits and Hospitalizations

We evaluated the impact of a comprehensive pediatric asthma management program (the Children's Asthma Wellness Program, CAWP) on the frequency of emergency department (ED) visits and hospital admissions. The CAWP generally consisted of 4 clinic sessions over a 1-year period, but some patients attended fewer clinic sessions, and some required additional clinic sessions due to incomplete asthma control. Patients were evaluated and treated by pediatric pulmonologists, nurse asthma care coordinator/educator, and social worker. We retrospectively reviewed program results over an 8-year period (2005?2013). We compared ED visits and hospital admissions before and after participation in the CAWP. There were 254 children referred to the CAWP; 172 children were enrolled. Fifty-four children (31%) received >6 sessions due to incomplete asthma control. On average, children requiring additional clinic sessions were older and more likely to be African American, hold Medicaid insurance, and have severe asthma. We obtained a minimum of 1-year preprogram and 1-year postprogram administrative data for 86 children (50%). Using each participating child as his/her own control, we found that taking part in the program decreased the risk of ED visits to 0.26 times the preprogram rate (P?Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140178/1/ped.2015.0561.pd

Macrophage activation state determines the response to rhinovirus infection in a mouse model of allergic asthma

Abstract Background The mechanisms by which viruses cause asthma exacerbations are not precisely known. Previously, we showed that, in ovalbumin (OVA)-sensitized and -challenged mice with allergic airway inflammation, rhinovirus (RV) infection increases type 2 cytokine production from alternatively-activated (M2) airway macrophages, enhancing eosinophilic inflammation and airways hyperresponsiveness. In this paper, we tested the hypothesis that IL-4 signaling determines the state of macrophage activation and pattern of RV-induced exacerbation in mice with allergic airways disease. Methods Eight week-old wild type or IL-4 receptor knockout (IL-4R KO) mice were sensitized and challenged with OVA and inoculated with RV1B or sham HeLa cell lysate. Results In contrast to OVA-treated wild-type mice with both neutrophilic and eosinophilic airway inflammation, OVA-treated IL-4R KO mice showed increased neutrophilic inflammation with few eosinophils in the airways. Like wild-type mice, IL-4R KO mice showed OVA-induced airway hyperreactivity which was further exacerbated by RV. There was a shift in lung cytokines from a type 2-predominant response to a type 1 response, including production of IL-12p40 and TNF-α. IL-17A was also increased. RV infection of OVA-treated IL-4R KO mice further increased neutrophilic inflammation. Bronchoalveolar macrophages showed an M1 polarization pattern and ex vivo RV infection increased macrophage production of TNF-α, IFN-γ and IL-12p40. Finally, lung cells from OVA-treated IL-4R KO mice showed reduced CD206+ CD301+ M2 macrophages, decreased IL-13 and increased TNF-α and IL-17A production by F4/80+, CD11b+ macrophages. Conclusions OVA-treated IL-4R KO mice show neutrophilic airway inflammation constituting a model of allergic, type 1 cytokine-driven neutrophilic asthma. In the absence of IL-4/IL-13 signaling, RV infection of OVA-treated mice increased type 1 cytokine and IL-17A production from conventionally-activated macrophages, augmenting neutrophilic rather than eosinophilic inflammation. In mice with allergic airways inflammation, IL-4R signaling determines macrophage activation state and the response to subsequent RV infection.http://deepblue.lib.umich.edu/bitstream/2027.42/109511/1/12931_2014_Article_1503.pd

IL‐1β prevents ILC2 expansion, type 2 cytokine secretion, and mucus metaplasia in response to early‐life rhinovirus infection in mice

BackgroundEarly‐life wheezing‐associated respiratory infection with human rhinovirus (RV) is associated with asthma development. RV infection of 6‐day‐old immature mice causes mucous metaplasia and airway hyperresponsiveness which is associated with the expansion of IL‐13‐producing type 2 innate lymphoid cells (ILC2s) and dependent on IL‐25 and IL‐33. We examined regulation of this asthma‐like phenotype by IL‐1β.MethodsSix‐day‐old wild‐type or NRLP3−/− mice were inoculated with sham or RV‐A1B. Selected mice were treated with IL‐1 receptor antagonist (IL‐1RA), anti‐IL‐1β, or recombinant IL‐1β.ResultsRhinovirus infection induced Il25, Il33, Il4, Il5, Il13, muc5ac, and gob5 mRNA expression, ILC2 expansion, mucus metaplasia, and airway hyperresponsiveness. RV also induced lung mRNA and protein expression of pro‐IL‐1β and NLRP3 as well as cleavage of caspase‐1 and pro‐IL‐1β, indicating inflammasome priming and activation. Lung macrophages were a major source of IL‐1β. Inhibition of IL‐1β signaling with IL‐1RA, anti‐IL‐1β, or NLRP3 KO increased RV‐induced type 2 cytokine immune responses, ILC2 number, and mucus metaplasia, while decreasing IL‐17 mRNA expression. Treatment with IL‐1β had the opposite effect, decreasing IL‐25, IL‐33, and mucous metaplasia while increasing IL‐17 expression. IL‐1β and IL‐17 each suppressed Il25, Il33, and muc5ac mRNA expression in cultured airway epithelial cells. Finally, RV‐infected 6‐day‐old mice showed reduced IL‐1β mRNA and protein expression compared to mature mice.ConclusionMacrophage IL‐1β limits type 2 inflammation and mucous metaplasia following RV infection by suppressing epithelial cell innate cytokine expression. Reduced IL‐1β production in immature animals provides a mechanism permitting asthma development after early‐life viral infection.Early‐life rhinovirus infection increases epithelial expression of the innate cytokines IL‐25 and IL‐33, expands (type 2 innate lymphoid cells) ILC2s, and enhances development of an asthma‐like phenotype. Rhinovirus causes macrophage (NLR family, pyrin domain containing 3) NLRP3 inflammasome activation and bioactive IL‐1β production. IL‐1β production, which is deficient in immature mice, attenuates production of IL‐25 and IL‐33, thereby protecting against rhinovirus‐induced asthma development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156197/3/all14241_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156197/2/all14241.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156197/1/all14241-sup-0001-FigS1.pd

Macrophage activation state determines the response to rhinovirus infection in a mouse model of allergic asthma

Abstract Background The mechanisms by which viruses cause asthma exacerbations are not precisely known. Previously, we showed that, in ovalbumin (OVA)-sensitized and -challenged mice with allergic airway inflammation, rhinovirus (RV) infection increases type 2 cytokine production from alternatively-activated (M2) airway macrophages, enhancing eosinophilic inflammation and airways hyperresponsiveness. In this paper, we tested the hypothesis that IL-4 signaling determines the state of macrophage activation and pattern of RV-induced exacerbation in mice with allergic airways disease. Methods Eight week-old wild type or IL-4 receptor knockout (IL-4R KO) mice were sensitized and challenged with OVA and inoculated with RV1B or sham HeLa cell lysate. Results In contrast to OVA-treated wild-type mice with both neutrophilic and eosinophilic airway inflammation, OVA-treated IL-4R KO mice showed increased neutrophilic inflammation with few eosinophils in the airways. Like wild-type mice, IL-4R KO mice showed OVA-induced airway hyperreactivity which was further exacerbated by RV. There was a shift in lung cytokines from a type 2-predominant response to a type 1 response, including production of IL-12p40 and TNF-α. IL-17A was also increased. RV infection of OVA-treated IL-4R KO mice further increased neutrophilic inflammation. Bronchoalveolar macrophages showed an M1 polarization pattern and ex vivo RV infection increased macrophage production of TNF-α, IFN-γ and IL-12p40. Finally, lung cells from OVA-treated IL-4R KO mice showed reduced CD206+ CD301+ M2 macrophages, decreased IL-13 and increased TNF-α and IL-17A production by F4/80+, CD11b+ macrophages. Conclusions OVA-treated IL-4R KO mice show neutrophilic airway inflammation constituting a model of allergic, type 1 cytokine-driven neutrophilic asthma. In the absence of IL-4/IL-13 signaling, RV infection of OVA-treated mice increased type 1 cytokine and IL-17A production from conventionally-activated macrophages, augmenting neutrophilic rather than eosinophilic inflammation. In mice with allergic airways inflammation, IL-4R signaling determines macrophage activation state and the response to subsequent RV infection.http://deepblue.lib.umich.edu/bitstream/2027.42/134573/1/12931_2014_Article_1503.pd

Mesenchymal Stromal Cells from Neonatal Tracheal Aspirates Demonstrate a Pattern of Lung-Specific Gene Expression

We have previously isolated mesenchymal stromal cells (MSCs) from the tracheal aspirates of premature neonates with respiratory distress. Although isolation of MSCs correlates with the development of bronchopulmonary dysplasia, the physiologic role of these cells remains unclear. To address this, we further characterized the cells, focusing on the issues of gene expression, origin, and cytokine expression. Microarray comparison of early passage neonatal lung MSC gene expression to cord blood MSCs and human fetal and neonatal lung fibroblast lines demonstrated that the neonatal lung MSCs differentially expressed 971 gene probes compared with cord blood MSCs, including the transcription factors Tbx2, Tbx3, Wnt5a, FoxF1, and Gli2, each of which has been associated with lung development. Compared with lung fibroblasts, 710 gene probe transcripts were differentially expressed by the lung MSCs, including IL-6 and IL-8/CXCL8. Differential chemokine expression was confirmed by protein analysis. Further, neonatal lung MSCs exhibited a pattern of Hox gene expression distinct from cord blood MSCs but similar to human fetal lung fibroblasts, consistent with a lung origin. On the other hand, limiting dilution analysis showed that fetal lung fibroblasts form colonies at a significantly lower rate than MSCs, and fibroblasts failed to undergo differentiation along adipogenic, osteogenic, and chondrogenic lineages. In conclusion, MSCs isolated from neonatal tracheal aspirates demonstrate a pattern of lung-specific gene expression, are distinct from lung fibroblasts, and secrete pro-inflammatory cytokines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90487/1/scd-2E2010-2E0494.pd

Influence of viral infection on the relationships between airway cytokines and lung function in asthmatic children

Abstract Background Few longitudinal studies examine inflammation and lung function in asthma. We sought to determine the cytokines that reduce airflow, and the influence of respiratory viral infections on these relationships. Methods Children underwent home collections of nasal lavage during scheduled surveillance periods and self-reported respiratory illnesses. We studied 53 children for one year, analyzing 392 surveillance samples and 203 samples from 85 respiratory illnesses. Generalized estimated equations were used to evaluate associations between nasal lavage biomarkers (7 mRNAs, 10 proteins), lung function and viral infection. Results As anticipated, viral infection was associated with increased cytokines and reduced FVC and FEV1. However, we found frequent and strong interactions between biomarkers and virus on lung function. For example, in the absence of viral infection, CXCL10 mRNA, MDA5 mRNA, CXCL10, IL-4, IL-13, CCL4, CCL5, CCL20 and CCL24 were negatively associated with FVC. In contrast, during infection, the opposite relationship was frequently found, with IL-4, IL-13, CCL5, CCL20 and CCL24 levels associated with less severe reductions in both FVC and FEV1. Conclusions In asthmatic children, airflow obstruction is driven by specific pro-inflammatory cytokines. In the absence of viral infection, higher cytokine levels are associated with decreasing lung function. However, with infection, there is a reversal in this relationship, with cytokine abundance associated with reduced lung function decline. While nasal samples may not reflect lower airway responses, these data suggest that some aspects of the inflammatory response may be protective against viral infection. This study may have ramifications for the treatment of viral-induced asthma exacerbations.https://deepblue.lib.umich.edu/bitstream/2027.42/146519/1/12931_2018_Article_922.pd

The role of endothelin-1 in hyperoxia-induced lung injury in mice

BACKGROUND: As prolonged hyperoxia induces extensive lung tissue damage, we set out to investigate the involvement of endothelin-1 (ET-1) receptors in these adverse changes. METHODS: Experiments were performed on four groups of mice: control animals kept in room air and a group of mice exposed to hyperoxia for 60 h were not subjected to ET-1 receptor blockade, whereas the dual ETA/ETB-receptor blocker tezosantan (TEZ) was administered via an intraperitoneal pump (10 mg/kg/day for 6 days) to other groups of normal and hyperoxic mice. The respiratory system impedance (Zrs) was measured by means of forced oscillations in the anesthetized, paralyzed and mechanically ventilated mice before and after the iv injection of ET-1 (2 μg). Changes in the airway resistance (Raw) and in the tissue damping (G) and elastance (H) of a constant-phase tissue compartment were identified from Zrs by model fitting. RESULTS: The plasma ET-1 level increased in the mice exposed to hyperoxia (3.3 ± 1.6 pg/ml) relative to those exposed to room air (1.6 ± 0.3 pg/ml, p < 0.05). TEZ administration prevented the hyperoxia-induced increases in G (13.1 ± 1.7 vs. 9.6 ± 0.3 cmH(2)O/l, p < 0.05) and H (59 ± 9 vs. 41 ± 5 cmH(2)O/l, p < 0.05) and inhibited the lung responses to ET-1. Hyperoxia decreased the reactivity of the airways to ET-1, whereas it elevated the reactivity of the tissues. CONCLUSION: These findings substantiate the involvement of the ET-1 receptors in the physiopathogenesis of hyperoxia-induced lung damage. Dual ET-1 receptor antagonism may well be of value in the prevention of hyperoxia-induced parenchymal damage