The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer

Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al

Lipocalin-2 Deficiency Attenuates Insulin Resistance Associated With Aging and Obesity

OBJECTIVE - The proinflammatory cytokines/adipokines produced from adipose tissue act in an autocrine and/or endocrine manner to perpetuate local inflammation and to induce peripheral insulin resistance. The present study investigates whether lipocalin-2 deficiency or replenishment with this adipokine has any impact on systemic insulin sensitivity and the underlying mechanisms. METHODS AND RESULTS - Under conditions of aging or dietary-/genetic-induced obesity, lipocalin-2 knockout (Lcn2-KO) mice show significantly decreased fasting glucose and insulin levels and improved insulin sensitivity compared with their wild-type littermates. Despite enlarged fat mass, inflammation and the accumulation of lipid peroxidation products are significantly attenuated in the adipose tissues of Lcn2-KO mice. Adipose fatty acid composition of these mice varies significantly from that in wild-type animals. The amounts of arachidonic acid (C20:4 n6) are elevated by aging and obesity and are paradoxically further increased in adipose tissue, but not skeletal muscle and liver of Lcn2-KO mice. On the other hand, the expression and activity of 12-lipoxygenase, an enzyme responsible for metabolizing arachidonic acid, and the production of tumor necrosis factor-α (TNF-α), a critical insulin resistance-inducing factor, are largely inhibited by lipocalin-2 deficiency. Lipocalin-2 stimulates the expression and activity of 12-lipoxygenase and TNF-α production in fat tissues. Cinnamyl-3,4- dihydroxy-α-cyanocinnamate (CDC), an arachidonate lipoxygenase inhibitor, prevents TNF-α expression induced by lipocalin-2. Moreover, treatment with TNF-α neutralization antibody or CDC significantly attenuated the differences of insulin sensitivity between wild-type and Lcn2-KO mice. CONCLUSIONS - Lipocalin-2 deficiency protects mice from developing aging- and obesity-induced insulin resistance largely by modulating 12-lipoxygenase and TNF-α levels in adipose tissue. © 2010 by the American Diabetes Association.link_to_OA_fulltex

Plasma neutrophil gelatinase associated lipocalin (NGAL) is associated with kidney function in uraemic patients before and after kidney transplantation

<p>Abstract</p> <p>Background</p> <p>Neutrophil gelatinase associated lipocalin (NGAL) is a biomarker of kidney injury. We examined plasma levels of NGAL in a cohort of 57 kidney allograft recipients (Tx group, 39 ± 13 years), a uraemic group of 40 patients remaining on the waiting list (47 ± 11 years) and a control group of 14 healthy subjects matched for age, sex and body mass index (BMI). The kidney graft recipients were studied at baseline before transplantation and 3 and 12 months after transplantation and the uraemic group at baseline and after 12 months.</p> <p>Methods</p> <p>NGAL was measured using a validated in-house Time-Resolved Immuno-flourometric assay (TRIFMA). Repeated measurements differed by < 10% and mean values were used for statistical analyses. Spearman rank order correlation analysis and the Kruskal-Wallis non-parametric test were used to evaluate the association of NGAL concentrations with clinical parameters.</p> <p>Results</p> <p>Plasma NGAL levels before transplantation in the Tx and uraemic groups were significantly higher than in the healthy controls (1,251 μg/L, 1,478 μg/L vs. 163 μg/L, p < 0.0001). In the Tx group NGAL concentrations were associated with serum creatinine (R = 0.51, p < 0.0001), duration of end-stage renal failure (R = 0.41, p = 0.002) and leukocyte count (R = 0.29, p < 0.026). At 3 and 12 months plasma NGAL concentrations declined to 223 μg/L and 243 μg/L, respectively and were associated with homocysteine (R = 0.39, p = 0.0051 and R = 0.47, p = 0.0007).</p> <p>Conclusions</p> <p>Plasma NGAL is a novel marker of kidney function, which correlates to duration of end-stage renal failure (ESRD) and serum creatinine in uraemic patients awaiting kidney transplantation. Plasma NGAL is associated with homocysteine in transplanted patients. The prognostic value of these findings requires further studies.</p

The role of specific biomarkers, as predictors of post-operative complications following flexible ureterorenoscopy (FURS), for the treatment of kidney stones: a single-centre observational clinical pilot-study in 37 patients

Abstract: Background: The number of patients diagnosed and subsequently treated for kidney stones is increasing, and as such the number of post-operative complications is likely to increase. At present, little is known about the role of specific biomarkers, following flexible ureterorenoscopy (FURS) for the surgical treatment of kidney stones. The main aim of the study was to evaluate the role of kidney and infection biomarkers, in patients undergoing FURS. Methods: Included were 37 patients (24 males, 13 females), who underwent elective FURS, for the treatment of kidney stones. Venous blood samples were collected from each patient: pre-operatively, and at 30 min, 2 and 4 h post-operatively. Changes to kidney (NGAL, Cystatin-C) and infection (MPO, PCT) biomarkers was quantified by means of ELISA, Biomerieux mini-vidas and Konelab 20 analysers. Results: Four patients developed post-operative complications (3 - UTIs with urinary retention, 1 - urosepsis. NGAL concentration increased significantly following FURS (p = 0.034). Although no significant changes were seen in Cystatin C, MPO and PCT (p ≥ 0.05) some key clinical observation were noted. Limiting factors for this study were the small number of patients recruited and restriction in blood sampling beyond 4 h. Conclusions: Although not confirmative, changes seen to biomarkers such as Cystatin C, NGAL and MPO in our observational clinical pilot-study may warrant further investigation, involving larger cohorts, to fully understand the role of these biomarkers and their potential association with post-operative complications which can develop following FURS

Transcriptome Kinetics of Circulating Neutrophils during Human Experimental Endotoxemia

Polymorphonuclear cells (neutrophils) play an important role in the systemic inflammatory response syndrome and the development of sepsis. These cells are essential for the defense against microorganisms, but may also cause tissue damage. Therefore, neutrophil numbers and activity are considered to be tightly regulated. Previous studies have investigated gene transcription during experimental endotoxemia in whole blood and peripheral blood mononuclear cells. However, the gene transcription response of the circulating pool of neutrophils to systemic inflammatory stimulation in vivo is currently unclear. We examined neutrophil gene transcription kinetics in healthy human subjects (n = 4) administered a single dose of endotoxin (LPS, 2 ng/kg iv). In addition, freshly isolated neutrophils were stimulated ex vivo with LPS, TNFα, G-CSF and GM-CSF to identify stimulus-specific gene transcription responses. Whole transcriptome microarray analysis of circulating neutrophils at 2, 4 and 6 hours after LPS infusion revealed activation of inflammatory networks which are involved in signaling of TNFα and IL-1α and IL-1β. The transcriptome profile of inflammatory activated neutrophils in vivo reflects extended survival and regulation of inflammatory responses. These changes in neutrophil transcriptome suggest a combination of early activation of circulating neutrophils by TNFα and G-CSF and a mobilization of young neutrophils from the bone marrow

Epithelial antimicrobial peptides in host defense against infection

One component of host defense at mucosal surfaces seems to be epithelium-derived antimicrobial peptides. Antimicrobial peptides are classified on the basis of their structure and amino acid motifs. Peptides of the defensin, cathelicidin, and histatin classes are found in humans. In the airways, α-defensins and the cathelicidin LL-37/hCAP-18 originate from neutrophils. β-Defensins and LL-37/hCAP-18 are produced by the respiratory epithelium and the alveolar macrophage and secreted into the airway surface fluid. Beside their direct antimicrobial function, antimicrobial peptides have multiple roles as mediators of inflammation with effects on epithelial and inflammatory cells, influencing such diverse processes as proliferation, immune induction, wound healing, cytokine release, chemotaxis, protease-antiprotease balance, and redox homeostasis. Further, antimicrobial peptides qualify as prototypes of innovative drugs that might be used as antibiotics, anti-lipopolysaccharide drugs, or modifiers of inflammation

Expression of Mir-21 and Mir-143 in Cervical Specimens Ranging from Histologically Normal through to Invasive Cervical Cancer

MicroRNA expression is severely disrupted in carcinogenesis, however limited evidence is available validating results from cell-line models in human clinical cancer specimens. MicroRNA-21 (mir-21) and microRNA-143 (mir-143) have previously been identified as significantly deregulated in a range of cancers including cervical cancer. Our goal was to investigate the expression patterns of several well-studied microRNA species in cervical samples and compare the results to cell line samples.We measured the expression of mir-21 and mir-143 in 142 formalin-fixed, paraffin embedded (FFPE) cervical biopsy tissue blocks, collected from Dantec Oncology Clinic, Dakar, Senegal. MicroRNA expression analysis was performed using Taqman-based real-time PCR assays. Protein immunohistochemical staining was also performed to investigate target protein expression on 72 samples. We found that mir-21 expression increased with worsening clinical diagnosis but that mir-143 was not correlated with histology. These observations were in stark contrast to previous reports involving cervical cancer cell lines in which mir-143 was consistently down-regulated but mir-21 largely unaffected. We also identified, for the first time, that cytoplasmic expression of Programmed Cell Death Protein 4 PDCD4; a known target of mir-21) was significantly lower in women with invasive cervical carcinoma (ICC) in comparison to those with cervical intraepithelial neoplasia (2-3) or carcinoma in situ (CIN2-3/CIS), although there was no significant correlation between mir-21 and PDCD4 expression, despite previous studies identifying PDCD4 transcript as a known mir-21 target.Whilst microRNA biomarkers have a number of promising features, more studies on expression levels in histologically defined clinical specimens are required to investigate clinical relevance of discovery-based studies. Mir-21 may be of some utility in predictive screening, given that we observed a significant correlation between mir-21 expression level and worsening histological diagnosis of cervical cancer

A Micro RNA Processing Defect in Rapidly Progressing Idiopathic Pulmonary Fibrosis

BACKGROUND: Idiopathic pulmonary fibrosis exhibits differential progression from the time of diagnosis but the molecular basis for varying progression rates is poorly understood. The aim of the present study was to ascertain whether differential miRNA expression might provide one explanation for rapidly versus slowly progressing forms of IPF. METHODOLOGY AND PRINCIPAL FINDINGS: miRNA and mRNA were isolated from surgical lung biopsies from IPF patients with a clinically documented rapid or slow course of disease over the first year after diagnosis. A quantitative PCR miRNA array containing 88 of the most abundant miRNA in the human genome was used to profile lung biopsies from 9 patients with rapidly progressing IPF, 6 patients with slowly progressing IPF, and 10 normal lung biopsies. Using this approach, 11 miRNA were significantly increased and 36 were significantly decreased in rapid biopsies compared with normal biopsies. Slowly progressive biopsies exhibited 4 significantly increased miRNA and 36 significantly decreased miRNA compared with normal lung. Among the miRNA present in IPF with validated mRNA targets were those with regulatory effects on epithelial-mesenchymal transition (EMT). Five miRNA (miR-302c, miR-423-5p, miR-210, miR-376c, and miR-185) were significantly increased in rapid compared with slow IPF lung biopsies. Additional analyses of rapid biopsies and fibroblasts grown from the same biopsies revealed that the expression of AGO1 and AGO2 (essential components of the miRNA processing RISC complex) were lower compared with either slow or normal lung biopsies and fibroblasts. CONCLUSION: These findings suggest that the development and/or clinical progression of IPF might be the consequence of aberrant miRNA processing

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference