Aquatic Macroinvertebrate Biodiversity Associated with Artificial Agricultural Drainage Ditches

Agricultural drainage channels and ditches are ubiquitous features in the lowland agricultural landscapes, built primarily to facilitate land drainage, irrigate agricultural crops and alleviate flood risk. Most drainage ditches are considered artificial waterbodies and are not typically included in routine monitoring programmes, and as a result the faunal and floral communities they support are poorly quantified. This paper characterizes the aquatic macroinvertebrate diversity (alpha, beta and gamma) of agricultural drainage ditches managed by an internal drainage board in Lincolnshire, UK. The drainage ditches support very diverse macroinvertebrate communities at both the site (alpha diversity) and landscape scale (gamma diversity) with the main arterial drainage ditches supporting greater numbers of taxa when compared to smaller ditches. Examination of the between site community heterogeneity (beta diversity) indicated that differences among ditches were high spatially and temporally. The results illustrate that both main arterial and side ditches make a unique contribution to aquatic biodiversity of the agricultural landscape. Given the need to maintain drainage ditches to support agriculture and flood defence measures, we advocate the application of principles from ‘reconciliation ecology’ to inform the future management and conservation of drainage ditches

Involvement of the p62/NRF2 signal transduction pathway on erythrophagocytosis

This deposit is composed by the main article plus the supplementary materials of the publication.Erythrophagocytosis, the phagocytic removal of damaged red blood cells (RBC), and subsequent phagolysosome biogenesis are important processes in iron/heme metabolism and homeostasis. Phagolysosome biogenesis implies the interaction of nascent phagosomes with endocytic compartments and also autophagy effectors. Here, we report that besides recruitment of microtubule-associated protein-1-light chain 3 (LC3), additional autophagy machinery such as sequestosome 1 (p62) is also acquired by single-membrane phagosomes at very early stages of the phagocytic process and that its acquisition is very important to the outcome of the process. In bone marrow-derived macrophages (BMDM) silenced for p62, RBC degradation is inhibited. P62, is also required for nuclear translocation and activation of the transcription factor Nuclear factor E2-related Factor 2 (NRF2) during erythrophagocytosis. Deletion of the Nrf2 allele reduces p62 expression and compromises RBC degradation. In conclusion, we reveal that erythrophagocytosis relies on an interplay between p62 and NRF2, potentially acting as protective mechanism to maintain reactive oxygen species at basal levels and preserve macrophage homeostasis.Fundação para a Ciência e a Tecnologia grants: (HMSP-ICT/0024/2010, UID/Multi/04462/2013, SFRH/BD/62197/2009, SFRH/BD/90258/2012, SFRH /BD/51877/2012, SFRH/BD/52293/2013, PTDC/SAU-TOX/116627/2010, HMSP-ICT/0022/2010 ); European Union FEDER support: (COMPETE, QREN, PT2020 Partnership Agreement), ERC grant: (ERC-2011-AdG 294709-DAMAGECONTROL).info:eu-repo/semantics/publishedVersio

From METS to malaria: RRx-001, a multi-faceted anticancer agent with activity in cerebral malaria

BACKGROUND: The survival of malaria parasites, under substantial haem-induced oxidative stress in the red blood cells (RBCs) is dependent on the pentose phosphate pathway (PPP). The PPP is the only source of NADPH in the RBC, essential for the production of reduced glutathione (GSH) and for protection from oxidative stress. Glucose-6-phosphate dehydrogenase (G6PD) deficiency, therefore, increases the vulnerability of erythrocytes to oxidative stress. In Plasmodium, G6PD is combined with the second enzyme of the PPP to create a unique bifunctional enzyme, named glucose-6-phosphate dehydrogenase–6-phosphogluconolactonase (G6PD-6PGL). RRx-001 is a novel, systemically non-toxic, epigenetic anticancer agent currently in Phase 2 clinical development for multiple tumour types, with activity mediated through increased nitric oxide (NO) production and PPP inhibition. The inhibition of G6PD and NO overproduction induced by RRx-001 suggested its application in cerebral malaria (CM). METHODS: Plasmodium berghei ANKA (PbA) infection in C57BL/6 mice is an experimental model of cerebral malaria (ECM) with several similar pathological features to human CM. This study uses intravital microscopy methods with a closed cranial window model to quantify cerebral haemodynamic changes and leukocyte adhesion to endothelial cells in ECM. RESULTS: RRx-001 had both single agent anti-parasitic activity and significantly increased the efficacy of artemether. In addition, RRx-001 preserved cerebral perfusion and reduced inflammation alone or combined with artemether. RRx-001’s effects were associated with inhibition of PPP (G6PD and G6PD-6PGL) and by improvements in microcirculatory flow, which may be related to the NO donating properties of RRx-001. CONCLUSION: The results indicate that RRx-001 could be used to potentiate the anti-malarial action of artemisinin, particularly on resistant strains, and to prevent infection

A new method to determine tissue specific tissue factor thrombomodulin activities: endotoxin and particulate air pollution induced disbalance.

ABSTRACT: BACKGROUND: Increase in tissue factor (TF) and loss in thrombomodulin (TM) antigen levels has been described in various inflammatory disorders. The functional consequences of such changes in antigen concentrations in the coagulation balance are, however, not known. This study was designed to assess the consequences of inflammation-driven organ specific functional properties of the procoagulant response. METHODS: Tissue specific procoagulant activity was assessed by adding tissue homogenate to normal human pool plasma and recording of the thrombin generation curve. The new technique was subsequently applied on two inflammation driven animal models: 1) mouse lipopolysaccharide (LPS) induced endotoxemia and 2) spontaneously hypertensive rats exposed to environmental air pollution (particulate matter (PM). RESULTS: Addition of lung tissue from untreated animals to human plasma suppressed the endogenous thrombin potential (ETP) (175 +/- 61 vs. 1437 +/- 112 nM.min for control). This inhibitory effect was due to TM, because a) it was absent in protein C deficient plasma and b) lungs from TMpro/pro mice allowed full thrombin generation (ETP: 1686 +/- 209 nM.min). The inhibitory effect of TM was lost after LPS administration to mice, which induced TF activity in lungs of C57Bl/6 mice as well as increased the ETP (941 +/- 523 vs. 194 +/- 159 nM.min for control). Another pro-inflammatory stimulus, PM dose-dependently increased TF in the lungs of spontaneously hypertensive rats at 4 and 48 hours after PM exposure. The ETP increased up to 48 hours at the highest concentration of PM (1441 +/- 289 nM.min vs. saline: 164 +/- 64 nM.min, p < 0.0001), suggesting a concentration- and time dependent reduction in TM activity. CONCLUSION: Inflammation associated procoagulant effects in tissues are dependent on variations in activity of the TF-TM balance. The application of these novel organ specific functional assays is a useful tool to monitor inflammation-driven shifts in the coagulation balance within animal or human tissues

Examining the role of Rac1 in tumor angiogenesis and growth: a clinically relevant RNAi-mediated approach.

Angiogenesis, the sprouting of new blood vessels from the pre-existing vasculature, is a well established target in anti-cancer therapy. It is thought that the Rho GTPase Rac1 is required during vascular endothelial growth factor (VEGF)-mediated angiogenesis. In the present study, we have used a clinically relevant RNA interference approach to silence Rac1 expression. Human umbilical vein endothelial cells were transiently transfected with non-specific control siRNA (siNS) or Rac1 siRNA (siRac1) using electroporation or Lipofectamine 2000. Functional assays with transfected endothelial cells were performed to determine the effect of Rac1 knockdown on angiogenesis in vitro. Silencing of Rac1 inhibited VEGF-mediated tube formation, cell migration, invasion and proliferation. In addition, treatment with Rac1 siRNA inhibited angiogenesis in an in vivo Matrigel plug assay. Intratumoral injections of siRac1 almost completely inhibited the growth of grafted Neuro2a tumors and reduced tumor angiogenesis. Together, these data indicate that Rac1 is an important regulator of VEGF-mediated angiogenesis. Knockdown of Rac1 may represent an attractive approach to inhibit tumor angiogenesis and growth

Taxol(®)-induced phosphatidylserine exposure and microvesicle formation in red blood cells is mediated by its vehicle Cremophor(®) EL.

AIM: The conventional clinical formulation of paclitaxel (PTX), Taxol®, consists of Cremophor® EL (CrEL) and ethanol. CrEL-formulated PTX is associated with acute hypersensitivity reactions, anemia and cardiovascular events. In this study, the authors investigated the effects of CrEL-PTX on red blood cells (RBCs) and compared these with the effects observed after exposure to the novel nanoparticle albumin-bound PTX, marketed as Abraxane®. RESULTS: The authors demonstrate that CrEL is primarily responsible for RBC lysis and induction of phosphatidylserine exposure. Phosphatidylserine-exposing RBCs showed increased association with endothelial cells in culture. The authors also identified CrEL as being responsible for vesiculation of RBCs. This is the first time that excipients have been shown to be involved in microvesicle formation. Microvesicles were taken up by endothelial cells. CONCLUSION: These results offer new insights into the side effect profile of Taxol, which is likely to have implications for patients with erythrocyte disorders. Abraxane did not induce any of these effects on RBCs, indicating that the choice of excipients can have a pronounced influence on the efficacy and side effects of drug molecules