Caveolin-1 in renal cell carcinoma promotes tumour cell invasion, and in co-operation with pERK predicts metastases in patients with clinically confined disease

Background: Up to 40% of patients initially diagnosed with clinically-confined renal cell carcinoma (RCC) and who undergo curative surgery will nevertheless relapse with metastatic disease (mRCC) associated with poor long term survival. The discovery of novel prognostic/predictive biomarkers and drug targets is needed and in this context the aim of the current study was to investigate a putative caveolin-1/ERK signalling axis in clinically confined RCC, and to examine in a panel of RCC cell lines the effects of caveolin-1 (Cav-1) on pathological processes (invasion and growth) and select signalling pathways. Methods: Using immunohistochemistry we assessed the expression of both Cav-1 and phosphorylated-ERK (pERK) in 176 patients with clinically confined RCC, their correlation with histological parameters and their impact upon disease-free survival. Using a panel of RCC cell lines we explored the functional effects of Cav-1 knockdown upon cell growth, cell invasion and VEGF-A secretion, as well Cav-1 regulation by cognate cell signalling pathways. Results: We found a significant correlation (P = 0.03) between Cav-1 and pERK in a cohort of patients with clinically confined disease which represented a prognostic biomarker combination (HR = 4.2) that effectively stratified patients into low, intermediate and high risk groups with respect to relapse, even if the patients’ tumours displayed low grade and/or low stage disease. In RCC cell lines Cav-1 knockdown unequivocally reduced cell invasive capacity while also displaying both pro-and anti-proliferative effects; targeted knockdown of Cav-1 also partially suppressed VEGF-A secretion in VHL-negative RCC cells. The actions of Cav-1 in the RCC cell lines appeared independent of both ERK and AKT/mTOR signalling pathways. Conclusion: The combined expression of Cav-1 and pERK serves as an independent biomarker signature with potential merit in RCC surveillance strategies able to predict those patients with clinically confined disease who will eventually relapse. In a panel of in-vitro RCC cells Cav-1 promotes cell invasion with variable effects on cell growth and VEGF-A secretion. Cav-1 has potential as a therapeutic target for the prevention and treatment of mRCC

Estimating the soil N2O emission intensity of croplands in northwest Europe

The application of nitrogenous fertilisers to agricultural soils is a major source of anthropogenic N2O emissions. Reducing the nitrogen (N) footprint of agriculture is a global challenge that depends, among other things, on our ability to quantify the N2O emission intensity of the world's most widespread and productive agricultural systems. In this context, biogeochemistry (BGC) models are widely used to estimate soil N2O emissions in agroecosystems. The choice of spatial scale is crucial because larger-scale studies are limited by low input data precision, while smaller-scale studies lack wider relevance. The robustness of large-scale model predictions depends on preliminary and data-demanding model calibration/validation, while relevant studies often omit the performance of output uncertainty analysis and underreport model outputs that would allow a critical assessment of results. This study takes a novel approach to these aspects. The study focuses on arable eastern Scotland – a data-rich region typical of northwest Europe in terms of edaphoclimatic conditions, cropping patterns and productivity levels. We used a calibrated and locally validated BGC model to simulate direct soil N2O emissions along with NO3 leaching and crop N uptake in fields of barley, wheat and oilseed rape. We found that 0.59&thinsp;% (±0.36) of the applied N is emitted as N2O while 37&thinsp;% (±6) is taken up by crops and 14&thinsp;% (±7) is leached as NO3. We show that crop type is a key determinant of N2O emission factors (EFs) with cereals having a low (mean EF&lt;0.6&thinsp;%), and oilseed rape a high (mean EF=2.48&thinsp;%), N2O emission intensity. Fertiliser addition was the most important N2O emissions driver suggesting that appropriate actions can reduce crop N2O intensity. Finally, we estimated a 74&thinsp;% relative uncertainty around N2O predictions attributable to soil data variability. However, we argue that higher-resolution soil data alone might not suffice to reduce this uncertainty.</p

Inflammatory adipocyte-derived extracellular vesicles promote leukocyte attachment to vascular endothelial cells

Background and aims. Obesity is associated with an increased risk of cardiovascular disease, but the mechanisms involved are not completely understood. In obesity, the adipocyte microenvironment is characterised by both hypoxia and inflammation. Therefore, we sought to determine whether extracellular vesicles (EVs) derived from adipocytes in this setting might be involved in mediating cardiovascular disease, specifically by promoting leukocyte attachment to vascular endothelial cells. Methods. Mature 3T3-L1 adipocytes were incubated for 24 h under control, TNF-α (30 ng/mL), hypoxia (1% O2), or TNF-α+hypoxia (30 ng/mL, 1% O2) conditions. EVs were isolated by differential ultracentrifugation and analysed by nanoparticle tracking analysis. Primary human umbilical vein endothelial cells (HUVECs) were treated with EVs for 6 h before being lysed for Western blotting to investigate changes in adhesion molecule production, or for use in leukocyte attachment assays. Results. EVs from adipocytes treated with TNF-α and TNF-α+hypoxia increased vascular cell adhesion molecule (VCAM-1) production in HUVECs compared to basal level (4.2 ± 0.6 and 3.8 ± 0.3-fold increase, respectively (p < 0.05)), an effect that was inhibited by an anti-TNF-α neutralising antibody. Production of other adhesion molecules (E-selectin, P-selectin, platelet endothelial cell adhesion molecule and VE-Cadherin) was unchanged. Pre-incubating HUVECs with TNF-α+hypoxia EVs significantly increased leukocyte attachment compared to basal level (3.0 ± 0.4-fold increase (p < 0.05)). Conclusions. Inflammatory adipocyte EVs induce VCAM-1 production in vascular endothelial cells, accompanied by enhanced leukocyte attachment. Preventing adipocyte derived EV-induced VCAM-1 upregulation may offer a novel therapeutic target in the prevention of obesity-driven cardiovascular disease

The value of Sentinel-2 spectral bands for the assessment of winter wheat growth and development

Leaf Area Index (LAI) and chlorophyll content are strongly related to plant development and productivity. Spatial and temporal estimates of these variables are essential for efficient and precise crop management. The availability of open-access data from the European Space Agency’s (ESA) Sentinel-2 satellite—delivering global coverage with an average 5-day revisit frequency at a spatial resolution of up to 10 metres—could provide estimates of these variables at unprecedented (i.e., sub-field) resolution. Using synthetic data, past research has demonstrated the potential of Sentinel-2 for estimating crop variables. Nonetheless, research involving a robust analysis of the Sentinel-2 bands for supporting agricultural applications is limited. We evaluated the potential of Sentinel-2 data for retrieving winter wheat LAI, leaf chlorophyll content (LCC) and canopy chlorophyll content (CCC). In coordination with destructive and non-destructive ground measurements, we acquired multispectral data from an Unmanned Aerial Vehicle (UAV)-mounted sensor measuring key Sentinel-2 spectral bands (443 to 865 nm). We applied Gaussian processes regression (GPR) machine learning to determine the most informative Sentinel-2 bands for retrieving each of the variables. We further evaluated the GPR model performance when propagating observation uncertainty. When applying the best-performing GPR models without propagating uncertainty, the retrievals had a high agreement with ground measurements—the mean R2 and normalised root-mean-square error (NRMSE) were 0.89 and 8.8%, respectively. When propagating uncertainty, the mean R2 and NRMSE were 0.82 and 11.9%, respectively. When accounting for measurement uncertainty in the estimation of LAI and CCC, the number of most informative Sentinel-2 bands was reduced from four to only two—the red-edge (705 nm) and near-infrared (865 nm) bands. This research demonstrates the value of the Sentinel-2 spectral characteristics for retrieving critical variables that can support more sustainable crop management practices

Evidence for adipocyte-derived extracellular vesicles in the human circulation

Adipocyte-derived extracellular vesicles (EVs) may serve as novel endocrine mediators of adipose tissue and impact upon vascular health. However, it is unclear whether adipocyte-derived EVs are present in the human circulation. Therefore, the purpose of this study was to seek evidence for the presence of adipocyte-derived EVs in circulating plasma. Size exclusion chromatography of platelet-free plasma identified fractions 5-10 as containing EVs by a peak in particle concentration, which corresponded with the presence of EV and adipocyte proteins. Pooling fractions 5-10 and subjecting to ultracentrifugation yielded a plasma EV sample, as verified by transmission electron microscopy (TEM) showing EV structures and Western blotting for EV (e.g. CD9 and Alix) and adipocyte markers. Magnetic beads and a solid phase assay were used to deplete the EV sample of the four major families of circulating EVs: platelet-, leukocyte-, endothelial- and erythrocyte-derived EVs. Post-depletion samples from both techniques contained EV structures as visualized by TEM, as well as CD9, Alix and classic adipocyte proteins. Post-depletion samples also contained a range of other adipocyte proteins from an adipokine array. Adipocyte proteins and adipokines are expressed in optimally processed plasma EV samples, suggesting that adipocyte-derived EVs are secreted into the human circulation