Project description:Human SCGB1A1 protein has been shown to be significantly reduced in BAL, sputum, and serum from humans with asthma as compared with healthy individuals. However, the mechanism of this reduction and its functional impact have not been entirely elucidated. By mining online datasets, we found that the mRNA of SCGB1A1 was significantly repressed in brushed human airway epithelial cells from individuals with asthma, and this repression appeared to be associated with reduced expression of FOXA2. Consistently, both Scgb1A1 and FoxA2 were downregulated in an ovalbumin-induced mouse model of asthma. Furthermore, compared with wild-type mice, Scgb1a1 knockout mice had increased airway hyperreactivity and inflammation when they were exposed to ovalbumin, confirming the antiinflammatory role of Scgb1a1 in protection against asthma phenotypes. To search for potential asthma-related stimuli of SCGB1A1 repression, we tested T-helper cell type 2 cytokines. Both IL-4 and IL-13 repressed epithelial expression of SCGB1A1 and FOXA2. Importantly, infection of epithelial cells with human rhinovirus similarly reduced expression of these two genes, which suggests that FOXA2 may be the common regulator of SCGB1A1. To establish the causal role of reduced FOXA2 in SCGB1A1 repression, we demonstrated that FOXA2 was required for SCGB1A1 expression at baseline. FOXA2 overexpression was sufficient to drive promoter activity and expression of SCGB1A1 and was also able to restore the repressed SCGB1A1 expression in IL-13-treated or rhinovirus-infected cells. Taken together, these findings suggest that low levels of epithelial SCGB1A1 in asthma are caused by reduced FOXA2 expression.
Project description:The high-lying vibrational states of the magnesium dimer (Mg2), which has been recognized as an important system in studies of ultracold and collisional phenomena, have eluded experimental characterization for half a century. Until now, only the first 14 vibrational states of Mg2 have been experimentally resolved, although it has been suggested that the ground-state potential may support five additional levels. Here, we present highly accurate ab initio potential energy curves based on state-of-the-art coupled-cluster and full configuration interaction computations for the ground and excited electronic states involved in the experimental investigations of Mg2. Our ground-state potential unambiguously confirms the existence of 19 vibrational levels, with ~1 cm-1 root mean square deviation between the calculated rovibrational term values and the available experimental and experimentally derived data. Our computations reproduce the latest laser-induced fluorescence spectrum and provide guidance for the experimental detection of the previously unresolved vibrational levels.
Project description:Lesions compatible with spirocercosis were found in the esophagus and aorta of an Andean fox from Cuzco, Peru. The esophageal and aortic lesions were 5.5 and 1.5 cm in diameter, respectively. A total of 12 adult nematodes (6 males and 6 females) were collected from the esophageal lesion, and all were identified as Spirocerca lupi by morphological and molecular methods. Molecular characterization was performed by analyzing two sources of the cox1 gene, and the sequences were compared with previous S. lupi sequences from other work deposited in GenBank. Analysis of the partial cox1 gene from S. lupi (n?=?3) showed 2 haplotypes and had 95-99% nucleotide similarity to previously described sequences. Also, molecular analysis showed that S. lupi is a very diverse group, due to the genetic variability of the partial sequences of the cox1 gene of Spirocerca. This study is the first to report finding of spirocercosis in the Andean fox.
Project description:Asthma encompasses a spectrum of heterogenous immune-mediated respiratory disorders sharing a similar clinical pattern characterized by cough, wheeze and exercise intolerance. In horses, equine asthma can be subdivided into severe or moderate asthma according to clinical symptoms and the extent of airway neutrophilic inflammation. While severe asthmatic horses are characterized by an elevated neutrophilic inflammation of the lower airways, cough, dyspnea at rest and high mucus secretion, horses with moderate asthma show a milder neutrophilic inflammation, exhibit intolerance to exercise but no labored breathing at rest. Yet, the physiopathology of different phenotypes of equine asthma remains poorly understood and there is a need to elucidate the underlying mechanisms tailoring those phenotypes in order to improve clinical management and elaborate novel therapeutic strategies. In this study, we sought to quantify the presence of neutrophil extracellular traps (NETs) in bronchoalveolar lavage fluids (BALF) of moderate or severe asthmatic horses and healthy controls, and assessed whether NETs correlated with disease severity. To this end, we evaluated the amounts of NETs by measuring cell-free DNA and MPO-DNA complexes in BALF supernatants or by quantifying NETs release by BALF cells by confocal microscopy. We were able to unequivocally identify elevated NETs levels in BALF of severe asthmatic horses as compared to healthy controls or moderate asthmatic horses. Moreover, we provided evidence that BALF NETs release was a specific feature seen in severe equine asthma, as opposed to moderate asthma, and correlated with disease severity. Finally, we showed that NETs could act as a predictive factor for severe equine asthma. Our study thus uniquely identifies NETs in BALF of severe asthmatic horses using three distinct methods and supports the idea that moderate and severe equine asthma do not rely on strictly similar pathophysiological mechanisms. Our data also suggest that NETs represent a relevant biomarker, a putative driver and a potential therapeutic target in severe asthma disease.
Project description:Alveolar macrophage (AM) is a mononuclear phagocyte key to the defense against respiratory infections. To understand AM's role in airway disease development, we examined the influence of Secretoglobin family 1a member 1 (SCGB1A1), a pulmonary surfactant protein, on AM development and function. In a murine model, high-throughput RNA-sequencing and gene expression analyses were performed on purified AMs isolated from mice lacking in Scgb1a1 gene and were compared with that from mice expressing the wild type Scgb1a1 at weaning (4 week), puberty (8 week), early adult (12 week), and middle age (40 week). AMs from early adult mice under Scgb1a1 sufficiency demonstrated a total of 37 up-regulated biological pathways compared to that at weaning, from which 30 were directly involved with antigen presentation, anti-viral immunity and inflammation. Importantly, these pathways under Scgb1a1 deficiency were significantly down-regulated compared to that in the age-matched Scgb1a1-sufficient counterparts. Furthermore, AMs from Scgb1a1-deficient mice showed an early activation of inflammatory pathways compared with that from Scgb1a1-sufficient mice. Our in vitro experiments with AM culture established that exogenous supplementation of SCGB1a1 protein significantly reduced AM responses to microbial stimuli where SCGB1a1 was effective in blunting the release of cytokines and chemokines (including IL-1b, IL-6, IL-8, MIP-1a, TNF-a, and MCP-1). Taken together, these findings suggest an important role for Scgb1a1 in shaping the AM-mediated inflammation and immune responses, and in mitigating cytokine surges in the lungs.
Project description:Steroids are the standard treatment for allergic airway inflammation in asthma, but steroid-refractory asthma poses a challenge. Group 2 innate lymphoid cells (ILC2s), such as T helper 2 (TH2) cells, produce key asthma-related type 2 cytokines. Recent insights from mouse and human studies indicate a potential connection between ILC2s and steroid-resistant asthma. Here, we highlight that lung ILC2s, rather than TH2 cells, can develop steroid resistance, allowing them to persist and maintain their disease-driving activity even during steroid treatment. The emergence of multipotent IL-5+IL-13+IL-17A+ ILC2s is associated with steroid-resistant ILC2s. The Janus kinase 3 (JAK3)/signal transducer and activator of transcription (STAT) 3, 5, and 6 pathways contribute to the acquisition of steroid-resistant ILC2s. The JAK3 inhibitor reduces ILC2 survival, proliferation, and cytokine production in vitro and ameliorates ILC2-driven Alternaria-induced asthma. Furthermore, combining a JAK3 inhibitor with steroids results in the inhibition of steroid-resistant asthma. These findings suggest a potential therapeutic approach for addressing this challenging condition in chronic asthma.
Project description:Airway obstruction is a hallmark of allergic asthma and is caused primarily by airway smooth muscle (ASM) hypercontractility. Airway inflammation leads to the release of cytokines that enhance ASM contraction by increasing ras homolog gene family, member A (RhoA) activity. The protective mechanisms that prevent or attenuate the increase in RhoA activity have not been well studied. Here, we report that mice lacking the gene that encodes the protein Milk Fat Globule-EGF factor 8 (Mfge8(-/-)) develop exaggerated airway hyperresponsiveness in experimental models of asthma. Mfge8(-/-) ASM had enhanced contraction after treatment with IL-13, IL-17A, or TNF-?. Recombinant Mfge8 reduced contraction in murine and human ASM treated with IL-13. Mfge8 inhibited IL-13-induced NF-?B activation and induction of RhoA. Mfge8 also inhibited rapid activation of RhoA, an effect that was eliminated by an inactivating point mutation in the RGD integrin-binding site in recombinant Mfge8. Human subjects with asthma had decreased Mfge8 expression in airway biopsies compared with healthy controls. These data indicate that Mfge8 binding to integrin receptors on ASM opposes the effect of allergic inflammation on RhoA activity and identify a pathway for specific inhibition of ASM hypercontractility in asthma.