Biological impact assessment of nanomaterial used in nanomedicine. introduction to the NanoTEST project.

Therapeutic nanoparticles (NPs) are used in nanomedicine as drug carriers or imaging agents, providing increased selectivity/specificity for diseased tissues. The first NPs in nanomedicine were developed for increasing the efficacy of known drugs displaying dose-limiting toxicity and poor bioavailability and for enhancing disease detection. Nanotechnologies have gained much interest owing to their huge potential for applications in industry and medicine. It is necessary to ensure and control the biocompatibility of the components of therapeutic NPs to guarantee that intrinsic toxicity does not overtake the benefits. In addition to monitoring their toxicity in vitro, in vivo and in silico, it is also necessary to understand their distribution in the human body, their biodegradation and excretion routes and dispersion in the environment. Therefore, a deep understanding of their interactions with living tissues and of their possible effects in the human (and animal) body is required for the safe use of nanoparticulate formulations. Obtaining this information was the main aim of the NanoTEST project, and the goals of the reports collected together in this special issue are to summarise the observations and results obtained by the participating research teams and to provide methodological tools for evaluating the biological impact of NPs

P719 Determinants of tobacco consumption in the Swiss IBD cohort

Background: Tobacco consumption is an important environmental factor in inflammatory bowel diseases (IBD). Our aim was to identified characteristics associated with smoking in Crohn's disease (CD) and Ulcerative colitis (UC). Methods: Adult UC and CD patients included in the Swiss IBD cohort study (SIBDCS) from Nov. 2006 to Nov. 2015 were asked about their smoking status. Patients were separated in two groups (active smokers vs. non-smokers). A logistic regression analysis was performed with smoking as main outcome

Differential Effects of the Mitochondria-Active Tetrapeptide SS-31 (D-Arg-dimethylTyr-Lys-Phe-NH₂) and Its Peptidase-Targeted Prodrugs in Experimental Acute Kidney Injury.

The mitochondria-active tetrapeptide SS-31 can control oxidative tissue damage in kidney diseases. To investigate other potential beneficial nephroprotective effects of SS-31, in vivo murine models of acute tubular injury and glomerular damage were developed. Reduction of acute kidney injury was demonstrated in mice treated with SS-31. The expression of mRNAs involved in acute inflammatory and oxidative stress responses in the diseased kidneys confirmed that SS-31 could regulate these pathways in our in vivo models. Furthermore, ex vivo histoenzymography of mouse kidneys showed that aminopeptidase A (APA), the enzyme involved in the processing of angiotensin (Ang) II to Ang III, was induced in the diseased kidneys, and its activity was inhibited by SS-31. As the renin-angiotensin system (RAS) is a main regulator of kidney functions, the modulation of Ang receptors (ATR) and APA by SS-31 was further investigated using mRNAs extracted from diseased kidneys. Following acute tubular and/or glomerular damage, the expression of the AT <sub>1</sub> R mRNA was upregulated, which could be selectively downregulated upon SS-31 administration to the animals. At the same time, SS-31 was able to increase the expression of the AT <sub>2</sub> R, which may contribute to limit renal damage. Consequently, SS-31-based prodrugs were developed as substrates and/or inhibitors for APA and were screened using cells expressing high levels of APA, showing its selective regulation by α-Glu-SS-31. Thus, a link between SS-31 and the RAS opens new therapeutic implications for SS-31 in kidney diseases

Alternate Grazing of Cattle and Horses reduces infections with Strongyle Parasites – a case study

Gastro-Intestinal Nematodes (GIN) impact on the health and the production of horses and cattle, especially regarding young animals.7,10 Mixed and alternate grazing of production animals (herbivores) for the prevention of GIN is an important element of pasture management with the potential benefit arising from the host-selectivity of numerous GIN species.6,9,12 Small ruminants, for example, harbour a number of strongyle parasite species, which will not lead to stable populations in cattle, and in turn, cattle strongyles such as Ostertagia ostertagi or Cooperia oncophora will not reach patency when ingested by sheep. A substantial number of studies have been performed on mixed and alternate grazing between sheep and cattle or goats and cattle and have overall proven its benefit for different climates and environments.1,3,8 Information on the effect of alternate or mixed grazing of cattle with equids is, however, scarce. This is surprising, as with the exception of liver flukes and the strongyle species Trichostrongylus axei and compared to the cattle/small ruminant grazing combination, horses share no GIN species with cattle. Only recently a French study by Forteau et. al. 5 has shown for the first time that mixed grazing of horses and cattle was beneficial for horses in terms of lower strongyle faecal egg counts. No information is, however, available as to whether the horse/cattle grazing combination is also advantageous in terms of reduced GIN infection in cattle

Endothelin-Receptor Antagonists beyond Pulmonary Arterial Hypertension: Cancer and Fibrosis.

The endothelin axis and in particular the two endothelin receptors, ETA and ETB, are targets for therapeutic intervention in human diseases. Endothelin-receptor antagonists are in clinical use to treat pulmonary arterial hypertension and have been under clinical investigation for the treatment of several other diseases, such as systemic hypertension, cancer, vasospasm, and fibrogenic diseases. In this Perspective, we review the molecules that have been evaluated in human clinical trials for the treatment of pulmonary arterial hypertension, as well as other cardiovascular diseases, cancer, and fibrosis. We will also discuss the therapeutic consequences of receptor selectivity with regard to ETA-selective, ETB-selective, or dual ETA/ETB antagonists. We will also consider which chemical characteristics are relevant to clinical use and the properties of molecules necessary for efficacy in treating diseases against which known molecules displayed suboptimal efficacy

Controlled assembly of SNAP-PNA-fluorophore systems on DNA templates to produce fluorescence resonance energy transfer

The SNAP protein is a widely used self-labeling tag that can be used for tracking protein localization and trafficking in living systems. A model system providing controlled alignment of SNAP-tag units can provide a new way to study clustering of fusion proteins. In this work, fluorescent SNAP-PNA conjugates were controllably assembled on DNA frameworks forming dimers, trimers, and tetramers. Modification of peptide nucleic acid (PNA) with the O6-benzyl guanine (BG) group allowed the generation of site-selective covalent links between PNA and the SNAP protein. The modified BG-PNAs were labeled with fluorescent Atto dyes and subsequently chemo-selectively conjugated to SNAP protein. Efficient assembly into dimer and oligomer forms was verified via size exclusion chromatography (SEC), electrophoresis (SDS-PAGE), and fluorescence spectroscopy. DNA directed assembly of homo- and hetero-dimers of SNAP-PNA constructs induced homo- and hetero-FRET, respectively. Longer DNA scaffolds controllably aligned similar fluorescent SNAP-PNA constructs into higher oligomers exhibiting homo-FRET. The combined SEC and homo-FRET studies indicated the 1:1 and saturated assemblies of SNAP-PNA-fluorophore:DNA formed preferentially in this system. This suggested a kinetic/stoichiometric model of assembly rather than binomially distributed products. These BG-PNA-fluorophore building blocks allow facile introduction of fluorophores and/or assembly directing moieties onto any protein containing SNAP. Template directed assembly of PNA modified SNAP proteins may be used to investigate clustering behavior both with and without fluorescent labels which may find use in the study of assembly processes in cells

Renin and angiotensinogen expression and functions in growth and apoptosis of human glioblastoma

The expression and function in growth and apoptosis of the renin-angiotensin system (RAS) was evaluated in human glioblastoma. Renin and angiotensinogen (AGT) mRNAs and proteins were found by in situ hybridisation and immunohistochemistry in glioblastoma cells. Angiotensinogen was present in glioblastoma cystic fluids. Thus, human glioblastoma cells produce renin and AGT and secrete AGT. Human glioblastoma and glioblastoma cells expressed renin, AGT, renin receptor, AT(2) and/or AT(1) mRNAs and proteins determined by RT-PCR and/or Western blotting, respectively. The function of the RAS in glioblastoma was studied using human glioblastoma cells in culture. Angiotensinogen, des(Ang I)AGT, tetradecapaptide renin substrate (AGT1-14), Ang I, Ang II or Ang III, added to glioblastoma cells in culture, did not modulate their proliferation, survival or death. Angiotensin-converting enzyme inhibitors did not diminish glioblastoma cell proliferation. However, the addition of selective synthetic renin inhibitors to glioblastoma cells decreased DNA synthesis and viable tumour cell number, and induced apoptosis. This effect was not counterbalanced by concomitant addition of Ang II. In conclusion, the complete RAS is expressed by human glioblastomas and glioblastoma cells in culture. Inhibition of renin in glioblastoma cells may be a potential approach to control glioblastoma cell proliferation and survival, and glioblastoma progression in combination therapy

Targeted γ-secretase inhibition of Notch signaling activation in acute renal injury.

The Notch pathway has been reported to control tissue damage in acute kidney diseases. To investigate potential beneficial nephroprotective effects of targeting Notch, we developed chemically functionalized γ-secretase inhibitors (GSIs) targeting γ-glutamyltranspeptidase (γ-GT) and/or γ-glutamylcyclotransferase (γ-GCT), two enzymes overexpressed in the injured kidney, and evaluated them in in vivo murine models of acute tubular and glomerular damage. Exposure of the animals to disease-inducing drugs together with the functionalized GSIs improved proteinuria and, to some extent, kidney dysfunction. The expression of genes involved in the Notch pathway, acute inflammatory stress responses, and the renin-angiotensin system was enhanced in injured kidneys, which could be downregulated upon administration of functionalized GSIs. Immunohistochemistry staining and Western blots demonstrated enhanced activation of Notch1 as detected by its cleaved active intracellular domain during acute kidney injury, and this was downregulated by concomitant treatment with the functionalized GSIs. Thus targeted γ-secretase-based prodrugs developed as substrates for γ-GT/γ-GCT have the potential to selectively control Notch activation in kidney diseases with subsequent regulation of the inflammatory stress response and the renin-angiotensin pathways