Background Mechanisms underlying esophageal remodeling with subepithelial fibrosis in eosinophilic esophagitis (EoE) have not been delineated. Objectives To explore a role for Epithelial Mesenchymal Transition (EMT) in EoE, and whether EMT resolves with treatment. Methods Esophageal biopsies from 60 children were immunostained for epithelial (cytokeratin) and mesenchymal (vimentin) EMT biomarkers, and EMT quantified. Subjects studied had EoE (n=17), EoE-indeterminate (n=15), GERD (n=7) or normal esophagus (n=21). EMT was analyzed for relationships to diagnosis, eosinophils, and indices of subepithelial fibrosis, eosinophil peroxidase (EPX) and TGF-β immunostaining. EMT was assessed in pre- and post-treatment biopsies from 18 EoE subjects treated with elemental diet, six-food elimination diet, or topical corticosteroids (n=6/group). Results TGF-β1 treatment of esophageal epithelial cells in vitro for 24hrs induced upregulation of mesenchymal genes characteristic of EMT including N-cadherin (3.3-fold), vimentin (2.1-fold) and fibronectin (7.5-fold). EMT in esophageal biopsies was associated with EoE (or indeterminate EoE), but not GERD or normal esophagus, and was correlated to eosinophils (r=0.691), EPX (r=0.738) and TGF-β (r=0.520) immunostaining, and fibrosis (r=0.644) indices. EMT resolved with EoE treatments that induced clinicopathologic remission with reduced eosinophils. EMT decreased significantly post-treatment by 74.1% overall in the 18 treated EoE subjects; pre- vs. post-treatment EMT scores–3.17±0.82 vs. 0.82±0.39 (p<0.001), with similar decreases within treatment groups. Pre-/post-treatment EMT was strongly correlated with eosinophils for combined (r=0.804, p< 0.001) and individual treatment groups. Conclusions EMT likely contributes to subepithelial fibrosis in EoE, resolves with treatments that decrease esophageal inflammation, and its resolution correlates with decreased numbers of esophageal eosinophils.
Rationale: Bioactive lipid mediators, derived from membrane lipid precursors, are released into the airway and airspace where they bind high-affinity cognate receptors and may mediate asthma pathogenesis. Lysophosphatidic acid (LPA), a bioactive lipid mediator generated by the enzymatic activity of extracellular autotaxin (ATX), binds LPA receptors, resulting in an array of biological actions on cell proliferation, migration, survival, differentiation, and motility, and therefore could mediate asthma pathogenesis.Objectives: To define a role for the ATX-LPA pathway in human asthma pathogenesis and a murine model of allergic lung inflammation. Methods: We investigated the profiles of LPA molecular species and the level of ATX exoenzyme in bronchoalveolar lavage fluids of human patients with asthma subjected to subsegmental bronchoprovocation with allergen. We interrogated the role of the ATX-LPA pathway in allergic lung inflammation using a murine allergic asthma model in ATX-LPA pathway-specific genetically modified mice. Measurements and Main Results: Subsegmental bronchoprovocation with allergen in patients with mild asthma resulted in a remarkable increase in bronchoalveolar lavage fluid levels of LPA enriched in polyunsaturated 22:5 and 22:6 fatty acids in association with increased concentrations of ATX protein. Using a triple-allergen mouse asthma model, we showed that ATX-overexpressing transgenic mice had a more severe asthmatic phenotype, whereas blocking ATX activity and knockdown of the LPA 2 receptor in mice produced a marked attenuation of Th2 cytokines and allergic lung inflammation. Conclusions: The ATX-LPA pathway plays a critical role in the pathogenesis of asthma. These preclinical data indicate that targeting the ATX-LPA pathway could be an effective antiasthma treatment strategy.Keywords: asthma; lysophosphatidic acid; autotaxin; allergic airway inflammation supplied the ATX inhibitor, GWJ-23. V.A., E.K., and I.N. were involved in discussions related to animal dosage. A.J.M. and S.S.S. provided breeding pairs of ATX-Tg and ATX 1/2 mice. S.J.A. managed the inflammatory cell purification core lab for the SBP-AG protocol, designed experiments, interpreted data, coordinated regular scientific research meetings for the project, and edited the manuscript. V.N. conceptualized the study, designed mouse experiments, interpreted data, provided genetically modified mice, and wrote part of and edited the manuscript. J.W.C. obtained the SBP-AG IRB and IND approval, supervised mouse experiments and performance of the human SBP-AG protocol, designed experiments, interpreted and analyzed data, and edited the manuscript. All authors contributed to data discussion and review of the manuscript.Correspondence and requests for reprints should be addressed to John W. What This Study Adds to the FieldThe enzyme autotaxin (ATX) and two of its LPA products, LPA 22:5 and LPA 22:6, are markedly and selectively increased in the bronchoalveolar lavage fluid of human patients with asthma in response to airway allergen ch...
GATA-1 and the ets factor PU.1 have been reported to functionally antagonize one another in the regulation of erythroid versus myeloid gene transcription and development. The CCAAT enhancer binding protein ⑀ (C/EBP⑀) is expressed as multiple isoforms and has been shown to be essential to myeloid (granulocyte) terminal differentiation. We have defined a novel synergistic, as opposed to antagonistic, combinatorial interaction between GATA-1 and PU.1, and a unique repressor role for certain C/EBP⑀ isoforms in the transcriptional regulation of a model eosinophil granulocyte gene, the major basic protein (MBP). The eosinophil-specific P2 promoter of the MBP gene contains GATA-1, C/EBP, and PU.1 consensus sites that bind these factors in nuclear extracts of the eosinophil myelocyte cell line, AML14.3D10. The promoter is transactivated by GATA-1 alone but is synergistically transactivated by low levels of PU.1 in the context of optimal levels of GATA-1. The C/EBP⑀ 27 isoform strongly represses GATA-1 activity and completely blocks GATA-1/PU.1 synergy. In vitro mutational analyses of the MBP-P2 promoter showed that both the GATA-1/PU.1 synergy, and repressor activity of C/EBP⑀ 27 are mediated via protein-protein interactions through the C/EBP and/or GATA-binding sites but not the PU.1 sites. Co-immunoprecipitations using lysates of AML14.3D10 eosinophils show that both C/EBP⑀ 32/30 and ⑀ 27 physically interact in vivo with PU.1 and GATA-1, demonstrating functional interactions among these factors in eosinophil progenitors. Our findings identify novel combinatorial protein-protein interactions for GATA-1, PU
Seminal plasma ingredients are important for maintenance of sperm viability. This study focuses on the effect of boar seminal plasma exosomes on sperm function during long-term liquid storage. Boar seminal plasma exosomes had typical nano-structure morphology as measured by scanning electron microscopy (SEM) and molecular markers such as AWN, CD9 and CD63 by western blot analysis. The effect on sperm parameters of adding different ratio of boar seminal plasma exosomes to boar sperm preparations was analyzed. Compared to the diluent without exosomes, the diluent with four times or sixteen times exosomes compared to original semen had higher sperm motility, prolonged effective survival time, improved sperm plasma membrane integrity (p < 0.05), increased total antioxidant capacity (T-AOC) activity and decreased malondialdehyde (MDA) content. The diluent containing four times concentration of exosomes compared to original semen was determined to inhibit premature capacitation, but not to influence capacitation induced in vitro. Inhibition of premature capacitation is likely related to the concentration of exosomes which had been demonstrated to transfer proteins including AWN and PSP-1 into sperm. In addition, using fluorescence microscopy and scanning electron microscopy analysis, it was demonstrated that exosomes in diluent were directly binding to the membrane of sperm head which could improve sperm plasma membrane integrity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.