Amrita Rao

ORMDL3 promotes eosinophil trafficking and activation via regulation of integrins and CD48

ORM (yeast)-Like protein isoform 3 (ORMDL3) has recently been identified as a candidate gene for susceptibility to asthma; however the mechanisms by which it contributes to asthma pathogenesis are not well understood. Here we demonstrate a functional role for ORMDL3 in eosinophils in the context of allergic inflammation. Eosinophils recruited to the airways of allergen-challenged mice express ORMDL3. ORMDL3 expression in bone marrow eosinophils is localized in the endoplasmic reticulum and is induced by IL-3 and eotaxin-1. Over-expression of ORMDL3 in eosinophils causes increased rolling, distinct cytoskeletal rearrangement, ERK (1/2) phosphorylation and nuclear translocation of NF-κB. Knock-down of ORMDL3 significantly inhibits activation-induced cell shape changes, adhesion and recruitment to sites of inflammation in vivo, combined with reduced expression of CD49d and CD18. Additionally, ORMDL3 regulates IL-3-induced expression of CD48 and CD48-mediated eosinophil degranulation. These studies show that ORMDL3 regulates eosinophil trafficking, recruitment and degranulation, further elucidating a role for this molecule in allergic asthma and potentially other eosinophilic disorders.

Regulation of eosinophilia and allergic airway inflammation by the glycan-binding protein galectin-1

Significance Allergic asthma is a chronic airway disease, and the number of individuals with asthma continues to grow. Eosinophils recruited to allergic airways contribute significantly to airway inflammation via release of proinflammatory mediators that cause epithelial tissue damage, bronchoconstriction, and airway remodeling. Here we show that galectin-1 (Gal-1), an endogenous immunoregulatory lectin, binds to eosinophil-expressed surface glycans to inhibit cell migration and induce apoptosis. Using a mouse model of allergic asthma, we show that mice lacking Gal-1 exhibit increased airway eosinophils and airway hyperresponsiveness compared with wild-type mice. Because Gal-1 plays an important role in regulating airway inflammation, identifying pathways to induce Gal-1 synthesis and/or favor its biological activity might enable exploitation of its proresolving function to suppress allergic asthma. Galectin-1 (Gal-1), a glycan-binding protein with broad antiinflammatory activities, functions as a proresolving mediator in autoimmune and chronic inflammatory disorders. However, its role in allergic airway inflammation has not yet been elucidated. We evaluated the effects of Gal-1 on eosinophil function and its role in a mouse model of allergic asthma. Allergen exposure resulted in airway recruitment of Gal-1–expressing inflammatory cells, including eosinophils, as well as increased Gal-1 in extracellular spaces in the lungs. In vitro, extracellular Gal-1 exerted divergent effects on eosinophils that were N-glycan– and dose-dependent. At concentrations ≤0.25 µM, Gal-1 increased eosinophil adhesion to vascular cell adhesion molecule-1, caused redistribution of integrin CD49d to the periphery and cell clustering, but inhibited ERK(1/2) activation and eotaxin-1–induced migration. Exposure to concentrations ≥1 µM resulted in ERK(1/2)-dependent apoptosis and disruption of the F-actin cytoskeleton. At lower concentrations, Gal-1 did not alter expression of adhesion molecules (CD49d, CD18, CD11a, CD11b, L-selectin) or of the chemokine receptor CCR3, but decreased CD49d and CCR3 was observed in eosinophils treated with higher concentrations of this lectin. In vivo, allergen-challenged Gal-1–deficient mice exhibited increased recruitment of eosinophils and CD3+ T lymphocytes in the airways as well as elevated peripheral blood and bone marrow eosinophils relative to corresponding WT mice. Further, these mice had an increased propensity to develop airway hyperresponsiveness and displayed significantly elevated levels of TNF-α in lung tissue. This study suggests that Gal-1 can limit eosinophil recruitment to allergic airways and suppresses airway inflammation by inhibiting cell migration and promoting eosinophil apoptosis.

High-fat diet promotes lung fibrosis and attenuates airway eosinophilia after exposure to cockroach allergen in mice

ABSTRACT Obesity is an important risk factor for asthma but the mechanistic basis for this association is not well understood. In the current study, the impact of obesity on lung inflammatory responses after allergen exposure was investigated. C57BL/6 mice maintained on a high-fat diet (HFD) or a normal diet (ND) after weaning were sensitized and challenged with cockroach allergen (CRA). Airway inflammation was assessed based on inflammatory cell recruitment, measurement of lung Th1-Th2 cytokines, chemokines, eicosanoids, and other proinflammatory mediators as well as airway hyperresponsiveness (AHR). CRA-challenged mice fed a HFD exhibited significantly decreased allergen-induced airway eosinophilia along with reduced lung IL-5, IL-13, LTC4, CCL11, and CCL2 levels as well as reduced mucus secretion and smooth muscle mass compared to ND fed mice. However, allergen-challenged HFD fed mice demonstrated significantly increased PAI-1 and reduced PGE2 levels in the lung relative to corresponding ND fed mice. Interestingly, saline-exposed HFD fed mice demonstrated elevated baseline levels of TGF-β1, arginase-1, hypoxia-inducible factor-1α, and lung collagen expression associated with decreased lung function compared to corresponding ND fed mice. These studies indicate that a HFD inhibits airway eosinophilia while altering levels of PAI-1 and PGE2 in response to CRA in mice. Further, a HFD can lead to the development of lung fibrosis even in the absence of allergen exposure which could be due to innate elevated levels of specific profibrotic factors, potentially affecting lung function during asthma.

Endothelial and leukocyte heparan sulfates regulate the development of allergen-induced airway remodeling in a mouse model

Heparan sulfate (HS) proteoglycans (HSPGs) participate in several aspects of inflammation because of their ability to bind to growth factors, chemokines, interleukins and extracellular matrix proteins as well as promote inflammatory cell trafficking and migration. We investigated whether HSPGs play a role in the development of airway remodeling during chronic allergic asthma using mice deficient in endothelial- and leukocyte-expressed N-deacetylase/N-sulfotransferase-1 (Ndst1), an enzyme involved in modification reactions during HS biosynthesis. Ndst1-deficient and wild-type (WT) mice exposed to repetitive allergen (ovalbumin [OVA]) challenge were evaluated for the development of airway remodeling. Chronic OVA-challenged WT mice exhibited increased HS expression in the lungs along with airway eosinophilia, mucus hypersecretion, peribronchial fibrosis, increased airway epithelial thickness and smooth muscle mass. In OVA-challenged Ndst1-deficient mice, lung eosinophil and macrophage infiltration as well as airway mucus accumulation, peribronchial fibrosis and airway epithelial thickness were significantly lower than in allergen-challenged WT mice along with a trend toward decreased airway smooth muscle mass. Leukocyte and endothelial Ndst 1 deficiency also resulted in significantly decreased expression of IL-13 as well as remodeling-associated mediators such as VEGF, FGF-2 and TGF-β1 in the lung tissue. At a cellular level, exposure to eotaxin-1 failed to induce TGF-β1 expression by Ndst1-deficient eosinophils relative to WT eosinophils. These studies suggest that leukocyte and endothelial Ndst1-modified HS contribute to the development of allergen-induced airway remodeling by promoting recruitment of inflammatory cells as well as regulating expression of pro-remodeling factors such as IL-13, VEGF, TGF-β1 and FGF-2 in the lung.

Tolerability of Repeat Use of Blue Light Cystoscopy with Hexaminolevulinate for Patients with Urothelial Cell Carcinoma.

Purpose: Hexaminolevulinate hydrochloride with blue light cystoscopy is approved by the U.S. Food and Drug Administration as an adjunct to white light cystoscopy for the detection of urothelial cell carcinoma. In this study we examined the tolerability of the repeat use of white light cystoscopy with blue light cystoscopy. Materials and Methods: We retrospectively reviewed the records of all patients who underwent white light cystoscopy with blue light cystoscopy using hexaminolevulinate hydrochloride during a 34‐month period at 2 institutions. We compared the incidence of adverse events after initial and subsequent procedures. We grouped, graded and assigned the degree of attribution for all adverse events. Results: A total of 180 patients underwent 269 white light cystoscopy with blue light cystoscopy procedures. Of those 180 patients 118 (65%) underwent white light cystoscopy with blue light cystoscopy only 1 time. The other 62 (35%) patients underwent white light cystoscopy with blue light cystoscopy 2 or more times, including 43 (24%) 2 times and 19 (10%) 3 or more times. We noted 89 adverse events out of 269 procedures (33%), of which 66 (74%) occurred after the first white light cystoscopy with blue light cystoscopy; 14 (16%) after the second time and 9 (10%) after the third time or more. We found no statistically significant difference in adverse events between those patients undergoing 1 vs 2 or more white light cystoscopy with blue light cystoscopy procedures (p=0.134). We observed 1 grade 3 adverse event and no grade 4 or 5 adverse events. None of the adverse events were classified as probably or definitely related to hexaminolevulinate hydrochloride. Conclusions: In this retrospective study we found no statistically significant difference in the frequency or the grade of adverse events between first and repeat use of white light cystoscopy with blue light cystoscopy using hexaminolevulinate hydrochloride.

Preoperative Incidence of Deep Venous Thrombosis in Patients With Bladder Cancer Undergoing Radical Cystectomy

OBJECTIVE To determine the preoperative incidence of subclinical lower-extremity deep vein thrombosis (DVT), as well as to evaluate the utility of preoperative DVT screening in patients with bladder cancer before undergoing radical cystectomy. MATERIALS AND METHODS Beginning in 2014, we prospectively instituted a policy of obtaining a screening lower-extremity duplex ultrasound on all patients within 7 days before undergoing radical cystectomy. We reviewed the electronic medical records of all patients at our institution who underwent radical cystectomy for bladder cancer from January 2012 through December 2015. The screened group (n = 65) underwent preoperative screening; the historical control group (n = 78) did not. Primary outcome was a lower-extremity duplex ultrasound positive screening. Secondary outcome measures included the development of symptomatic venous thromboembolism (VTE) postoperatively, and the rate and severity of complications. RESULTS DVT was identified in 13.9% of patients before undergoing cystectomy. Univariate analysis demonstrated an increased risk of subclinical DVT in patients who were exposed to neoadjuvant chemotherapy (35.3% vs 5.1%, P = .008). Postoperatively, there was a nonsignificant trend of lower DVT rate in the screened group compared to historical control. Overall complication rate and severity were similar between the groups. CONCLUSION Subclinical DVT is present in a significant number of pre-cystectomy patients, especially those exposed to neoadjuvant chemotherapy. Ultrasound screening in patients before undergoing radical cystectomy may identify opportunities for early intervention to reduce morbidity and mortality associated with perioperative DVT or venous thromboembolism in the cystectomy population.

Knob protein enhances epithelial barrier integrity and attenuates airway inflammation

Background: Altered epithelial physical and functional barrier properties along with TH1/TH2 immune dysregulation are features of allergic asthma. Regulation of junction proteins to improve barrier function of airway epithelial cells has the potential for alleviation of allergic airway inflammation. Objective: We sought to determine the immunomodulatory effect of knob protein of the adenoviral capsid on allergic asthma and to investigate its mechanism of action on airway epithelial junction proteins and barrier function. Methods: Airway inflammation, including junction protein expression, was evaluated in allergen‐challenged mice with and without treatment with knob. Human bronchial epithelial cells were exposed to knob, and its effects on expression of junction proteins and barrier integrity were determined. Results: Administration of knob to allergen‐challenged mice suppressed airway inflammation (eosinophilia, airway hyperresponsiveness, and IL‐5 levels) and prevented allergen‐induced loss of airway epithelial occludin and E‐cadherin expression. Additionally, knob decreased expression of TH2‐promoting inflammatory mediators, specifically IL‐33, by murine lung epithelial cells. At a cellular level, treatment of human bronchial epithelial cells with knob activated c‐Jun N‐terminal kinase, increased expression of occludin and E‐cadherin, and enhanced epithelial barrier integrity. Conclusion: Increased expression of junction proteins mediated by knob leading to enhanced epithelial barrier function might mitigate the allergen‐induced airway inflammatory response, including asthma.

Community Breast Health Education for Immigrants and Refugees: Lessons Learned in Outreach Efforts to Reduce Cancer Disparities

Community-academic partnerships are vital to address cancer disparities in geographic areas with diverse socioeconomic, language, and cultural barriers. Regarding breast health, immigrant and refugee women are a particularly vulnerable population, with considerably lower mammography rates than most communities, including racial and ethnic minorities. To promote health care equity in this high-risk population, we developed a community-academic partnership (CAP) model to promote breast health education at community faith-based centers in the city of Milwaukee, WI. In this paper, we describe the success of our partnerships, our lessons learned, and future directions.