Improving the Value of Standard Toxicity Test Data in REACH

Worldwide, environmental risk assessment strategies are based on the assumption that measuring direct effects of single substances, using a few single species tests, in combination with safety factors correcting for extrapolation inconsistencies, can be used to protect higher levels of biological organization, such as populations and even ecosystems. At the same time, we are currently facing a range of pollution problems (Millennium Ecosystem Assessment Series 2005), of which some could at least indirectly be linked to the fact that this assumption may not be fully valid. Consequently, there is an ongoing scientific debate on whether current chemical control protocols are sufficient for protection of ecosystems, and numerous suggestions for improvements have been presented by the scientific community, e.g. alternative tests and testing strategies. On the other hand, few of these suggestions actually reach the regulatory world (or become implemented), and risk assessment today basically follows the same paradigm as 30 years ago. While the new REACH regime is exceptionally ambitious, this chapter observes several problems and gaps in this regulatory framework. We suggest measures and approaches which imply increased ecological realism and understanding in future regulatory work

A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe

Plasticity of Blood- and Lymphatic Endothelial Cells and Marker Identification

Peer reviewe

Anti-CD73 antibody therapy inhibits breast tumor growth and metastasis

Extracellular adenosine is a potent immunosuppressor that accumulates during tumor growth. We performed proof-of-concept studies investigating the therapeutic potential and mechanism of action of monoclonal antibody (mAb)-based therapy against CD73, an ecto-enzyme overexpressed on breast-cancer cells that catalyzes the dephosphorylation of adenosine monophosphates into adenosine. We showed that anti-CD73 mAb therapy significantly delayed primary 4T1.2 and E0771 tumor growth in immune-competent mice and significantly inhibited the development of spontaneous 4T1.2 lung metastases. Notably, anti-CD73 mAb therapy was essentially dependent on the induction of adaptive anti-tumor immune responses. Knockdown of CD73 in 4T1.2 tumor cells confirmed the tumor-promoting effects of CD73. In addition to its immunosuppressive effect, CD73 enhanced tumor-cell chemotaxis, suggesting a role for CD73-derived adenosine in tumor metastasis. Accordingly, administration of adenosine-5′-N-ethylcarboxamide to tumor-bearing mice significantly enhanced spontaneous 4T1.2 lung metastasis. Using selective adenosine-receptor antagonists, we showed that activation of A2B adenosine receptors promoted 4T1.2 tumor-cell chemotaxis in vitro and metastasis in vivo. In conclusion, our study identified tumor-derived CD73 as a mechanism of tumor immune escape and tumor metastasis, and it also established the proof of concept that targeted therapy against CD73 can trigger adaptive anti-tumor immunity and inhibit metastasis of breast cancer

Pregnancy-induced fluctuations in functional T-cell subsets in multiple sclerosis patients

Background: During pregnancy, especially during the third trimester, multiple sclerosis (MS) disease activity is reduced. It is not known which factors mediate this disease amelioration. Objective: To study whether the frequency of two important T-cell subsets, T-helper 17 (Th17) and regulatory T-cells (Treg), is altered in relation to pregnancy-induced MS disease amelioration. Methods: Each individual was tested longitudinally, after sampling of blood at timepoints before pregnancy, during the first and third trimester, and in the early post-partum period. Frequencies of Th17 cells were assessed after short (4 hours) re-stimulation of peripheral blood lymphocytes with PMA and ionomycin, followed by flow cytometry using CD4, CD45RO and IL-17A antibodies. To assess peripheral blood Treg frequencies, we used six-colour flow cytometry with antibodies against CD3, CD4, CD25, CD127, FoxP3 and HLA-DR, to specifically identify Treg. Results: Both MS patients (n = 9) and controls (n = 8) displayed unaltered Th17 frequencies during pregnancy. In contrast, circulating Treg frequency significantly decreased in MS patients (n = 15) during the first and third (p < 0.001) trimesters compared with the period before pregnancy. In the post-partum period, the frequency of circulating Treg again resurged back to near pre-pregnancy levels. In controls (n = 15) comparable frequency kinetics were observed in that post-partum a significant increase in circulating Treg frequency was detected compared with the first (p < 0.001) and third (p = 0.012) trimester. Conclusions: Third trimester amelioration is not related to the fluctuation of circulating Th17 cells. Furthermore, a paradoxical decrease of immunosuppressive circulating Tregs can be observed during this phase, both in MS patients and controls