8-Oxoguanine DNA glycosylase-1-mediated DNA repair is associated with Rho GTPase activation and α-smooth muscle actin polymerization

Reactive oxygen species (ROS) are activators of cell signaling and modify cellular molecules, including DNA. 8-Oxo-7,8-dihydroguanine (8-oxoG) is one of the prominent lesions in oxidatively damaged DNA, whose accumulation is causally linked to various diseases and aging processes, whereas its etiological relevance is unclear. 8-OxoG is repaired by the 8-oxoguanine DNA glycosylase-1 (OGG1)-initiated DNA base excision repair (BER) pathway. OGG1 binds free 8-oxoG and this complex functions as an activator of Ras family GTPases. Here we examined whether OGG1-initiated BER is associated with the activation of Rho GTPase and mediates changes in the cytoskeleton. To test this possibility, we induced OGG1- initiated BER in cultured cells and mouse lungs and used molecular approaches such as active Rho pull- down assays, siRNA ablation of gene expression, immune blotting, and microscopic imaging. We found that OGG1 physically interacts with Rho GTPase and, in the presence of 8-oxoG base, increases Rho–GTP levels in cultured cells and lungs, which mediates α-smooth muscle actin (α-SMA) polymerization into stress fibers and increases the level of α-SMA in insoluble cellular/tissue fractions. These changes were absent in cells lacking OGG1. These unexpected data and those showing that 8-oxoG repair is a lifetime process suggest that, via Rho GTPase, OGG1 could be involved in the cytoskeletal changes and organ remodeling observed in various chronic diseases

The Role of 8-Oxoguanine DNA Glycosylase-1 in Inflammation

Many, if not all, environmental pollutants/chemicals and infectious agents increase intracellular levels of reactive oxygen species (ROS) at the site of exposure. ROS not only function as intracellular signaling entities, but also induce damage to cellular molecules including DNA. Among the several dozen ROS-induced DNA base lesions generated in the genome, 8-oxo-7,8-dihydroguanine (8-oxoG) is one of the most abundant because of guanine’s lowest redox potential among DNA bases. In mammalian cells, 8-oxoG is repaired by the 8-oxoguanine DNA glycosylase-1 (OGG1)-initiated DNA base excision repair pathway (OGG1–BER). Accumulation of 8-oxoG in DNA has traditionally been associated with mutagenesis, as well as various human diseases and aging processes, while the free 8-oxoG base in body fluids is one of the best biomarkers of ongoing pathophysiological processes. In this review, we discuss the biological significance of the 8-oxoG base and particularly the role of OGG1–BER in the activation of small GTPases and changes in gene expression, including those that regulate pro-inflammatory chemokines/cytokines and cause inflammation

Analysis of a Panel of 48 Cytokines in BAL Fluids Specifically Identifies IL-8 Levels as the Only Cytokine that Distinguishes Controlled Asthma from Uncontrolled Asthma, and Correlates Inversely with FEV1

We sought to identify cells and cytokines in bronchoalveolar lavage (BAL) fluids that distinguish asthma from healthy control subjects and those that distinguish controlled asthma from uncontrolled asthma. Following informed consent, 36 human subjects were recruited for this study. These included 11 healthy control subjects, 15 subjects with controlled asthma with FEV1≥80% predicted and 10 subjects with uncontrolled asthma with FEV1 2.4%) were a higher BAL fluid IL-8 levels, and a lower FEV1 in the latter group. By contrast, compared to eosinophil-normal asthma (eosinophils≤0.3%), eosinophil-high asthma (eosinophils>0.3%) had higher levels of IL-5, IL-13, IL-16, and PDGF-bb, but same neutrophil percentage, IL-8, and FEV1. Our results identify neutrophils and IL-8 are the only inflammatory components in BAL fluids that distinguish controlled asthma from uncontrolled asthma, and both correlate inversely with FEV1

Antigen-Induced Expression of CD203c on Basophils Predicts IgE-mediated Wheat Allergy

Background: For in vitro diagnosis of wheat allergy, specific IgE to wheat is known to be a poor predictive marker. Oral food challenge, the gold standard for the diagnosis, is accompanied by a risk of severe induced reactions. Reliable in vitro tests are needed to be developed for safe indication for oral challenge. Objective: We examined the utility of a basophil activation marker, CD203c, for the diagnosis of IgE-mediated wheat allergy. Methods: Fifty-eight children with suspected wheat allergy with positive CAP-FEIA to wheat were enrolled. On 70 occasions, the clinical distinction between patients with wheat allergy (WA) and patients tolerant to wheat (TW) was made by means of an oral food challenge test or recent history of immediate allergic reactions or tolerance after ingestion of wheat. Twelve replicate evaluations were performed in 9 patients over more than a 6-month interval. Thirty two patients on 43 occasions were diagnosed with WA and 27 were confirmed to be TW. One patient had both diagnoses 18 months apart. Peripheral blood was incubated with fractionated wheat extracts, purified native omega-5 gliadin (nOG5) and recombinant omega-5 gliadin (rOG5). Expression of CD203c on basophils was then analyzed by flow cytometry using a commercial kit. Results: All wheat proteins induced concentration-dependent enhancement of CD203c expression in WA, but did not in TW. The analysis of receiver operating characteristics (ROC) showed that nOG5-induced CD203chigh% values provided the best power for discriminating between WA and TW, with a sensitivity of 85.0% and specificity of 77.0% at the cut-off level of 14.4%. AUC for CD203c with nOG5 were significantly higher than that for conventional CAP-FEIA, 0.89 and 0.73, respectively (p < 0.01). Conclusions: Measurement of nOG-induced enhancement of CD203c on basophils is useful for the diagnosis of immediate wheat allergy in children

BALF data for Dyrad

This excel file has all data underlying the findings described in their manuscrip

Biomarkers for Allergen Immunotherapy in Cedar Pollinosis

To initiate, monitor, and complete effective immunotherapy, biomarkers to predict and visualize the immune responses are needed. First, we need to identify the right candidate for immunotherapy. Secondly, the immune responses induced by immunotherapy should be monitored. For the first objective, analysis of polymorphisms of candidate genes may be helpful, but still be in development. Regarding biomarkers for immune responsese, there are numerous reports that evaluate immunotherapy-induced immune changes such as suppression of effector cells, deviation to Th1 cytokine production, and induction of regulatory T cells. No standardized methods, however, have been established. Among them, a functional assay of blocking IgG activity, the IgE-facilitated allergen binding assay, may be useful. We quantitated induced expression of an activation marker, CD203c, on basophils and found that the assay efficiently predicts sensitivity to particular allergen and severity of the allergen-induced symptoms. In patients who received rush immunotherapy for Japanese cedar pollinosis, reduction in CD203c expression after the therapy was observed, suggesting the utility of the test for monitoring immunotherapy