Late fetal and newborn granulopoiesis but not active renin is increased by maternal captopril treatment during perinatal kidney development

Renin expression follows vascular development through the mouse kidney, regressing to glomerular poles by about P10, where renin is stored in dense core granules in juxtaglomerular cells. Homeostatic challenge to blood pressure causes release of active renin from the granules and recruitment of the renin lineage cells. We investigated the response to homeostatic challenge during late fetal development and following birth in a transgenic line expressing GFP under the renin promotor. Pregnant females were treated with water or captopril (30mg/kg/day), which inhibits angiotensin converting enzyme, from E15.5. We found an increase in renin transcription and expression by P1 following captopril treatment, with granulation increased at the glomerular poles and major arteries from E18.5. At P1, the granules showed a wide variation in electron density. Notably, rough endoplasmic reticulum was expanded in vascular smooth muscle cells (VSMCs) of captopril-treated pups at both time-points suggesting increased transcriptional activity. Paracrystalline material was observed in granules of captopril treated fetuses at E18.5 and in both treated and untreated pups at P1. Renin expression and some granules were confirmed in the kidney VSMCs by immuno-gold staining against GFP at E18.5. Importantly, we found no difference in active renin content between kidneys from treated and untreated pups at either age group. We therefore demonstrate a disconnect between granulation and active renin production in newborns when exposed to homeostatic challenge in utero

Inhibition of the purinergic P2X7 receptor improves renal perfusion in angiotensin-II-infused rats

Chronic activation of the renin angiotensin system promotes hypertension, renal microvascular dysfunction, tissue hypoxia and inflammation. We found previously that the injurious response to excess angiotensin II (ANGII) is greater in F344 rats, whereas Lewis rats are renoprotected, despite similar hypertension. We further identified p2rx7, encoding the P2X7 receptor (P2X7R), as a candidate gene for differential susceptibility and here we have tested the hypothesis that activation of P2X7R promotes vascular dysfunction under high ANGII tone. 14-day infusion of ANGII at 30ng/min into F344 rats increased blood pressure by ~15mmHg without inducing fibrosis or albuminuria. In vivo pressure natriuresis was suppressed, medullary perfusion reduced by ~50% and the cortico-medullary oxygenation gradient disrupted. Selective P2X7R antagonism restored pressure natriuresis, promoting a significant leftward shift in the intercept and increasing the slope. Sodium excretion was increased 6 fold and blood pressure normalized. The specific P2X7R antagonist AZ11657312 increased renal medullary perfusion, but only in ANGII-treated rats. Tissue oxygenation was improved by P2X7R blockade, particularly in poorly oxygenated regions of the kidney. Activation of P2X7R induces microvascular dysfunction and regional hypoxia when ANGII is elevated. These pro-inflammatory effects may contribute to progression of renal injury induced by chronic ANGII

Transcriptome changes in age-related macular degeneration

Age-related macular degeneration (AMD) is a debilitating, common cause of visual impairment. While the last decade has seen great progress in understanding the pathophysiology of AMD, the molecular changes that occur in eyes with AMD are still poorly understood. In the current issue of Genome Medicine, Newman and colleagues present the first systematic transcriptional profile analysis of AMD-affected tissues, providing a comprehensive set of expression data for different regions (macula versus periphery), tissues (retina versus retinal pigment epithelium (RPE)/choroid), and disease state (control versus early or advanced AMD). Their findings will serve as a foundation for additional systems-level research into the pathogenesis of this blinding disease

Effect of P2X4 and P2X7 receptor antagonism on the pressure diuresis relationship in rats.

Reduced glomerular filtration, hypertension and renal microvascular injury are hallmarks of chronic kidney disease, which has a global prevalence of ~10%. We have shown previously that the Fischer (F344) rat has lower GFR than the Lewis rat, and is more susceptible to renal injury induced by hypertension. In the early stages this injury is limited to the pre-glomerular vasculature. We hypothesized that poor renal hemodynamic function and vulnerability to vascular injury are causally linked and genetically determined. In the present study, normotensive F344 rats had a blunted pressure diuresis relationship, compared with Lewis rats. A kidney microarray was then interrogated using the Endeavour enrichment tool to rank candidate genes for impaired blood pressure control. Two novel candidate genes, P2rx7 and P2rx4, were identified, having a 7- and 3- fold increased expression in F344 rats. Immunohistochemistry localized P2X4 and P2X7 receptor expression to the endothelium of the pre-glomerular vasculature. Expression of both receptors was also found in the renal tubule; however there was no difference in expression profile between strains. Brilliant Blue G (BBG), a relatively selective P2X7 antagonist suitable for use in vivo, was administered to both rat strains. In Lewis rats, BBG had no effect on blood pressure, but increased renal vascular resistance, consistent with inhibition of some basal vasodilatory tone. In F344 rats BBG caused a significant reduction in blood pressure and a decrease in renal vascular resistance, suggesting that P2X7 receptor activation may enhance vasoconstrictor tone in this rat strain. BBG also reduced the pressure diuresis threshold in F344 rats, but did not alter its slope. These preliminary findings suggest a physiological and potential pathophysiological role for P2X7 in controlling renal and/or systemic vascular function, which could in turn affect susceptibility to hypertension-related kidney damage

Assessment of genetically modified maize MIR604 for renewal authorisation under Regulation (EC) No 1829/2003 (application EFSA‐GMO‐RX‐013)

Following the submission of application EFSA‐GMO‐RX‐013 under Regulation (EC) No 1829/2003 from Syngenta Crop Protection NV/SA, the EFSA Panel on Genetically Modified Organisms (GMO) was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the insect‐resistant genetically modified maize MIR604, for food and feed uses, excluding cultivation within the EU. The data received in the context of this renewal application contained post‐market environmental monitoring reports, a systematic search and evaluation of literature, updated bioinformatic analyses, and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequence of the event in maize MIR604 considered for renewal is identical to the corrected sequence of the originally assessed event, the GMO Panel concludes that there is no evidence in renewal application EFSA‐GMO‐RX‐013 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on maize MIR604

Assessment of genetically modified oilseed rape GT73 for renewal authorisation under Regulation (EC) No 1829/2003 (application EFSA‐GMO‐RX‐002)

Following the submission of application EFSA‐GMO‐RX‐002 under Regulation (EC) No 1829/2003 from Monsanto Company, the Panel on Genetically Modified Organisms of EFSA (GMO) was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the herbicide‐tolerant genetically modified oilseed rape GT73. The data received in the context of this renewal application contained post‐market environmental monitoring reports, a systematic search and evaluation of literature, updated bioinformatic analyses and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequence of the event in oilseed rape GT73 considered for renewal of authorisation is identical to the sequence of the originally assessed event, the GMO Panel concludes that there is no evidence in renewal application EFSA‐GMO‐RX‐002 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on oilseed rape GT73

Statement complementing the EFSA Scientific Opinion on application (EFSA‐GMO‐NL‐2009‐75) for placing on the market of genetically modified oilseed rape Ms8 × Rf3 × GT73 and subcombinations, which have not been authorised previously (i.e. Ms8 × GT73 and Rf3 × GT73) independently of their origin, for food and feed uses, import and processing, with the exception of isolated seed protein for food, under Regulation (EC) No 1829/2003), taking into consideration additional information

The EFSA Panel on Genetically Modified Organisms (GMO) previously assessed oilseed rape Ms8 × Rf3 × GT73 and its subcombinations Ms8 × GT73 and Rf3 × GT73 according to the scope as defined in the application EFSA‐GMO‐NL‐2009‐75, and was not in the position to complete the safety assessment of products rich in protein, such as rapeseed protein isolates or products of this nature in animal feeding. Following a mandate from the European Commission, the GMO Panel assessed a 28‐day toxicity study in mice with the glyphosate oxidoreductase (GOXv247) protein, provided to complement information related to application EFSA‐GMO‐NL‐2009‐75 for the placing on the market of oilseed rape Ms8 × Rf3 × GT73 and its subcombinations Ms8 × GT73 and Rf3 × GT73, for food and feed uses, import and processing, with the exception of isolated seed protein for food. The 28‐day toxicity study on Escherichia coli‐ produced GOXv247 protein did not show adverse effects in mice, at the gavage doses up to 1000 mg/kg body weight (bw) per day. Taking into account its previous assessment on EFSA‐GMO‐NL‐2009‐75 and the outcome of the 28‐day toxicity study in mice with the GOXv247 protein provided in this mandate, the GMO Panel, based on a weight of evidence approach, concludes that food and feed containing, consisting and produced from genetically modified oilseed rape Ms8 × Rf3 × GT73 and its sub combinations Ms8 × GT73 and Rf3 × GT73, are as safe as its conventional counterpart, according to the scope as defined in the application EFSA‐GMO‐NL‐2009‐75

Assessment of genetically modified maize MON 89034 for renewal authorisation under Regulation (EC) No 1829/2003 (application EFSA-GMO-RX-015)

Following the submission of application EFSA-GMO-RX-015 under Regulation (EC) No 1829/2003 from Bayer Agriculture BVBA, the EFSA Panel on Genetically Modified Organisms (GMO Panel) was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the insect-resistant genetically modified maize MON 89034, for food and feed uses, excluding cultivation within the EU. The data received in the context of this renewal application contained post-market environmental monitoring reports, a systematic search and evaluation of literature, updated bioinformatic analyses and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequence of the event in maize MON 89034 considered for renewal is identical to the sequence of the originally assessed event, the GMO Panel concludes that there is no evidence in renewal application EFSA-GMO-RX-015 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on maize MON 89034