Analysis of ADAM8 in the tumor microenvironment of Pancreatic Ductal Adenocarcinoma

The expression of the membrane-bound protein ADAM8 is associated with various diseases such as respiratory diseases, liver injury, neuroinflammation, and cancer. Despite its low expression level in distinct cell types, ADAM8 can be upregulated to significant levels upon specific stimuli. Unlike inflammatory processes, ADAM8 is constitutively overexpressed in cancer diseases as it has been described for brain, breast, lung, and pancreatic cancer, and correlates almost exclusively with poor survival. Most importantly, PDAC demonstrated that ADAM8 plays an essential role in tumor cell migration, invasion, and metastasis in vitro and in vivo. The treatment of PDAC is impeded by its high metastatic ability and the lack of specific symptoms leading to late detection of the tumor disease and a high mortality rate. Therefore, there is a high urgency to identify biomarkers for early detection as well as specific therapeutic targets. The first aim of this thesis was to detect ADAM8 in tumor tissue sections of the Marburg PDAC patient cohort. DAB staining of all patients revealed a positive detection of ADAM8 in all sections, suggesting an essential role for ADAM8 in PDAC tumor and disease progression. Nevertheless, ADAM8 expression did not correlate with patient overall survival. ADAM8 expression was also detected in tumor-associated macrophages, NK cells, and neutrophils, indicating that ADAM8 is involved in the recruitment of immune cells to the tumor microenvironment and thus might promote tumor progression. However, the quantification and subsequent analysis of the neutrophil density in post-capillary venules within the tumor areas disclosed the significant negative correlation of neutrophils positive for ADAM8 with overall survival, emphasizing the potential of ADAM8 for diagnosis and prognosis of PDAC. In the second part of this study, ADAM8 was identified as an active protease in exosomes derived from sera of PDAC patients by applying a bead-coupled FACS analysis. Elevated ADAM8 levels in exosomes correlated with disease progression. In addition, two miRNAs, miR-451 and miR-720, that are reported to exert tumor-promoting functions, were dysregulated in exosomes derived from PDAC patients compared to healthy individuals. The validation of these two miRNAs in exosomes from pancreatic cancer cell lines Panc89 control and Panc89 ADAM8 knockout cells revealed the ADAM8-dependent upregulation of miR-720 and downregulation of miR-451. Based on these results, the detection of ADAM8, miR-451, and miR-720 in exosomes may facilitate diagnosis, as this regulatory profile allows the differentiation between different stages of PDAC disease. The final part of this work investigates the regulatory function of ADAM8 in the tumor microenvironment. As a protease involved in tumor cell invasion and metastasis, MMP-9 was previously described to be regulated by ADAM8 via MAPK/CREB signaling. Based on this finding, MMP-9 expression was validated in Panc89 control and ADAM8 knockout cells. However, ADAM8 was shown to regulate MMP-9 activity but not MMP-9 expression. Further analysis of other regulatory proteins revealed the ADAM8-dependent downregulation of LCN2, a protein that promotes PDAC progression and is involved in the regulation of MMP-9 activity. These data suggest that ADAM8 regulates LCN2 expression levels to control MMP-9 activity, promoting invasion and metastasis in PDAC. In addition, the described regulatory effect of ADAM8 on LCN2 and MMP-9 was enhanced by the co-culture of Panc89 cell with THP-1 derived macrophages demonstrating the essential role of ADAM8 in the PDAC tumor microenvironment and thus underlining the potential as a therapeutic target. The functional analysis of exosomes derived from Panc89 control and ADAM8 knockout cells demonstrated an ADAM8-dependent release of LCN2 and revealed that ADAM8 is sorted as a proteolytically active enzyme in exosomes. The presence of the ADAM8 in extracellular vesicles and the ability to exert specific regulatory functions in the tumor microenvironment by either cleavage of essential proteins or regulating particular genes involved in tumor progression offers the possibility to develop advanced treatment strategies and to improve the early detection of PDAC disease

Translation and linguistic validation of the German Challenging Behaviour Scale for formal caregivers of people with dementia in nursing homes

© 2018 Springer Publishing Company. Background and Purpose: The Challenging Behavior Scale (CBS) measures the behavior of individuals with dementia. The study aims to translate the English CBS into German (CBS-G) and test its linguistic validity. Methods: The two-panel approach was used to translate the CBS. Nursing home staff reviewed the unambiguity and familiarity of the CBS-G items and the adequateness of the examples used to describe the items. Content validity indexes (CVI) and modified kappa (k) coefficients were calculated. Results: Most of the CBS-G items had excellent CVI and k values for both unambiguity and familiarity. All examples were viewed as adequate. Conclusion: A German version of the CBS that is linguistically equivalent to the original CBS is available but needs further testing of its psychometric properties

A comparison of iron absorption in adults and infants consuming identical infant formulas

Fe absorption was estimated in adults and infants from the erythrocyte incorporation of Fe isotopes added to infant formula. Fe absorption was measured in adults using radioisotopes, and in infants with a stable-isotope technique. In adults, the geometric mean Fe absorption from a ready-to-feed soya formula with its native phytic acid content was 2·4%. This increased to 6·0% (P < 0·05) after almost complete dephytinization. In infants, mean Fe absorption values were 3·9 and 8·7% respectively from the same products (P <0·05). In adults, mean Fe absorption from a spray-dried soya formula containing 110mg ascorbic acid/I was 4·1%, increasing to 5·3% (P < 0·05) when ascorbic acid was doubled to 220 mg/l. In infants, mean Fe absorption values were 5·7 and 9·5% (P < 0·05) from the same products. Mean Fe absorption from a milk-based formula was 6·5% in adults compared with 6·7% in infants. All meals in the adult and infant studies were fed using an identical meal size of 217g. Increasing the meal size threefold in adults did not change fractional Fe absorption. Mean Fe absorption values for each meal were lower in adults than in infants, but the relative inhibitory effect of phytic acid and the enhancing effect of ascorbic acid were similar. We conclude that Fe absorption studies in adults can be used to assess the influence of enhancers and inhibitors of Fe absorption in infant formulas fed to infants. Further studies, however, are required to extend these findings to weaning foods and complete meal

The Future of History: Investigating the Preservation of Information in the Digital Age

Abstract This study investigates the challenges of preserving information in the digital age, and explores how this may affect the future of historical knowledge. The study is based on a series of semi-structured interviews with forty-one historians, archivists, librarians, and web researchers. While the results reject the idea of a single ‘digital black hole’ in historical records, they emphasize the importance of the issue for the future of history, and the complexity of the solutions to be adopted. The need for planning, for education, and for cooperation between historians and the information professions is also emphasized

Discovery of Dimeric Arylsulfonamides as Potent ADAM8 Inhibitors

The metalloproteinase ADAM8 is upregulated in several cancers but has a dispensable function under physiological conditions. In tumor cells, ADAM8 is involved in invasion, migration and angiogenesis. The use of bivalent inhibitors could impair migration and invasion, through the double binding to a homodimeric form of ADAM8 located on the cell surface of tumor cells. Herein we report the rational design and synthesis of the first dimeric ADAM8 inhibitors selective over ADAM10 and MMPs. Bivalent derivatives have been obtained by dimerizing the structure of a previously described ADAM17 inhibitor, JG26. In particular, derivative 2 showed to inhibit ADAM8 proteolytic activity in vitro and in cell-based assays, at nanomolar concentration. Moreover, it was more effective than the parent monomeric compound in blocking invasiveness in breast cancer MDA-MB-231 cell line, thus supporting our hypothesis about the importance of inhibiting the active homodimer of ADAM8

Expression of the Metalloproteinase ADAM8 Is Upregulated in Liver Inflammation Models and Enhances Cytokine Release In Vitro

Acute and chronic liver inflammation is driven by cytokine and chemokine release from various cell types in the liver. Here, we report that the induction of inflammatory mediators is associated with a yet undescribed upregulation of the metalloproteinase ADAM8 in different murine hepatitis models. We further show the importance of ADAM8 expression for the production of inflammatory mediators in cultured liver cells. As a model of acute inflammation, we investigated liver tissue from lipopolysaccharide- (LPS-) treated mice in which ADAM8 expression was markedly upregulated compared to control mice. In vitro, stimulation with LPS enhanced ADAM8 expression in murine and human endothelial and hepatoma cell lines as well as in primary murine hepatocytes. The enhanced ADAM8 expression was associated with an upregulation of TNF-α and IL-6 expression and release. Inhibition studies indicate that the cytokine response of hepatoma cells to LPS depends on the activity of ADAM8 and that signalling by TNF-α can contribute to these ADAM8-dependent effects. The role of ADAM8 was further confirmed with primary hepatocytes from ADAM8 knockout mice in which TNF-α and IL-6 induction and release were considerably attenuated. As a model of chronic liver injury, we studied liver tissue from mice undergoing high-fat diet-induced steatohepatitis and again observed upregulation of ADAM8 mRNA expression compared to healthy controls. In vitro, ADAM8 expression was upregulated in hepatoma, endothelial, and stellate cell lines by various mediators of steatohepatitis including fatty acid (linoleic-oleic acid), IL-1β, TNF-α, IFN-γ, and TGF-β. Upregulation of ADAM8 was associated with the induction and release of proinflammatory cytokines (TNF-α and IL-6) and chemokines (CX3CL1). Finally, knockdown of ADAM8 expression in all tested cell types attenuated the release of these mediators. Thus, ADAM8 is upregulated in acute and chronic liver inflammation and is able to promote inflammation by enhancing expression and release of inflammatory mediators

The Usefulness of Elemental Iron for Cereal Flour Fortification: a Sustain Task Force Report

Fortification of cereal flours may be a useful public health strategy to combat iron deficiency. Cereal flours that are used shortly after production (e.g., baking flour) can be fortified with soluble iron compounds, such as ferrous sulfate, whereas the majority of flours stored for longer periods is usually fortified with elemental iron powders to avoid unacceptable sensory changes. Elemental iron powders are less well absorbed than soluble iron compounds and they vary widely in their absorption depending on manufacturing method and physicochemical characteristics. Costs vary with powder type, but elemental iron powders are generally less expensive than ferrous sulfate. This review evaluates the usefulness of the different elemental iron powders based on results from in vitro studies, rat assays, human bioavailability studies, and efficacy studies monitoring iron status in human subjects. It concludes that, at the present time, only electrolytic iron powder can be recommended as an iron fortificant. Because it is only approximately half as well absorbed as ferrous sulfate, it should be added to provide double the amount of iro

Obesity Is Not Associated with Antimicrobial Treatment Failure for Intra-Abdominal Infection

Background: Obesity and commonly associated comorbidities are known risk factors for the development of infections. However, the intensity and duration of antimicrobial treatment are rarely conditioned on body mass index (BMI). In particular, the influence of obesity on failure of antimicrobial treatment for intra-abdominal infection (IAI) remains unknown. We hypothesized that obesity is associated with recurrent infectious complications in patients treated for IAI. Methods: Five hundred eighteen patients randomized to treatment in the Surgical Infection Society Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial were evaluated. Patients were stratified by obese (BMI ≥30) versus non-obese (BMI≥30) status. Descriptive comparisons were performed using Chi-square test, Fisher exact test, or Wilcoxon rank-sum tests as appropriate. Multivariable logistic regression using a priori selected variables was performed to assess the independent association between obesity and treatment failure in patients with IAI. Results: Overall, 198 (38.3%) of patients were obese (BMI ≥30) versus 319 (61.7%) who were non-obese. Mean antibiotic d and total hospital d were similar between both groups. Unadjusted outcomes of surgical site infection (9.1% vs. 6.9%, p?=?0.36), recurrent intra-abdominal infection (16.2% vs. 13.8, p?=?0.46), death (1.0% vs. 0.9%, p?=?1.0), and a composite of all complications (25.3% vs. 19.8%, p?=?0.14) were also similar between both groups. After controlling for appropriate demographics, comorbidities, severity of illness, treatment group, and duration of antimicrobial therapy, obesity was not independently associated with treatment failure (c-statistic: 0.64). Conclusions: Obesity is not associated with antimicrobial treatment failure among patients with IAI. These results suggest that obesity may not independently influence the need for longer duration of antimicrobial therapy in treatment of IAI versus non-obese patients.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140219/1/sur.2015.213.pd