Modeling complement activation on human glomerular microvascular endothelial cells

Introduction: Atypical hemolytic uremic syndrome (aHUS) is a rare kidney disease caused by dysregulation of the complement alternative pathway. The complement dysregulation specifically leads to damage to the glomerular endothelium. To further understand aHUS pathophysiology, we validated an ex vivo model for measuring complement deposition on both control and patient human glomerular microvascular endothelial cells (GMVECs). Methods: Endothelial cells were incubated with human test sera and stained with an anti-C5b-9 antibody to visualize and quantify complement depositions on the cells with immunofluorescence microscopy.Results: First, we showed that zymosan-activated sera resulted in increased endothelial C5b-9 depositions compared to normal human serum (NHS). The levels of C5b-9 depositions were similar between conditionally immortalized (ci)GMVECs and primary control GMVECs. The protocol with ciGMVECs was further validated and we additionally generated ciGMVECs from an aHUS patient. The increased C5b-9 deposition on control ciGMVECs by zymosan-activated serum could be dose-dependently inhibited by adding the C5 inhibitor eculizumab. Next, sera from five aHUS patients were tested on control ciGMVECs. Sera from acute disease phases of all patients showed increased endothelial C5b-9 deposition levels compared to NHS. The remission samples showed normalized C5b-9 depositions, whether remission was reached with or without complement blockage by eculizumab. We also monitored the glomerular endothelial complement deposition of an aHUS patient with a hybrid complement factor H (CFH)/CFH-related 1 gene during follow-up. This patient had already chronic kidney failure and an ongoing deterioration of kidney function despite absence of markers indicating an aHUS flare. Increased C5b-9 depositions on ciGMVECs were observed in all samples obtained throughout different diseases phases, except for the samples with eculizumab levels above target. We then tested the samples on the patient’s own ciGMVECs. The C5b-9 deposition pattern was comparable and these aHUS patient ciGMVECs also responded similar to NHS as control ciGMVECs. Discussion: In conclusion, we demonstrate a robust and reliable model to adequately measure C5b-9-based complement deposition on human control and patient ciGMVECs. This model can be used to study the pathophysiological mechanisms of aHUS or other diseases associated with endothelial complement activation ex vivo.</p

In vivo effect of Neuropeptide F on ecdysteroidogenesis in adult female desert locusts (Schistocerca gregaria)

Neuropeptides are important regulatory factors that mediate key life processes, both in vertebrates and invertebrates. Many insect neuropeptides display pleiotropic activities, which means that they can influence multiple aspects of insect physiology. In the fruit fly, Drosophila melanogaster, Neuropeptide F (NPF) mediates diverse physiological processes, such as learning, stress responses, feeding and male courtship behavior. In locusts, only a truncated form of the predicted "full-length" NPF, the nonapeptide "trNPF", has been isolated. This nonapeptide previously proved to be biologically active, since it was shown to influence food intake and weight increase, as well as oocyte growth in adult female desert locusts (Schistocerca gregaria [Forskål]). In the present study, we have further analyzed the effect of trNPF on female reproductive physiology in S. gregaria. We confirmed that daily trNPF injections in adult females elicit an increase of oocyte size. In addition, an RNAi-mediated knockdown of the Schgr-NPF precursor transcript in adult female locusts resulted in the opposite effect, i.e. significantly smaller oocytes. Moreover, we discovered that daily injections of trNPF in adult female S. gregaria, caused higher ecdysteroid titers in the ovaries and accelerated the appearance of ecdysteroid peaks in the hemolymph of these animals. The RNAi-based knockdown of the Schgr-NPF precursor transcript clearly resulted in reduction of both hemolymph and ovarian ecdysteroid concentrations, confirming the stimulatory effects of trNPF injections on adult female ecdysteroid levels. The observed results are discussed in relation to previous reports on NPF activities in locusts and other insects.publisher: Elsevier articletitle: In vivo effect of Neuropeptide F on ecdysteroidogenesis in adult female desert locusts (Schistocerca gregaria) journaltitle: Journal of Insect Physiology articlelink: http://dx.doi.org/10.1016/j.jinsphys.2013.03.005 content_type: article copyright: Copyright © 2013 Elsevier Ltd. All rights reserved.status: publishe

Neurohormonal regulation of reproduction and feeding in the desert locust Schistocerca gregaria

The desert locust Schistocerca gregaria (Orthoptera), is a notorious pest insect that is able to inflict major damage to the agricultural production in large parts of the world. As in other animal species (both vertebrates and invertebrates), neurohormones play important roles in the regulation of body physiology in this insect. This report summarizes interesting findings of our research group on the neurohormonal regulation of reproductive physiology and food intake in the desert locust, by focusing on Neuropeptide F (NPF: the invertebrate homolog of the vertebrate Neuropeptide Y), the CRF-like diuretic hormone (CRF/DH) and the Ovary Maturating Parsins (OMP). In addition to the S. gregaria NPF-precursor encoding cDNA, we were able to identify two precursor cDNA sequences of this species, each encoding the CRF/DH, as well as one of both large Schgr-OMP isoforms. Quantitative “real-time” RTPCR measurements demonstrated that these precursors are mainly expressed in the central nervous system, while expression of the NPF precursor was also clearly detected in the digestive system (mainly in the midgut). By means of feeding experiments (combined with RNAi knockdown and peptide injections), we were able to show that NPF increased food intake while CRF/DH decreased food intake. The physiological effects of the studied neurohormones were further analyzed using RNAi, as well as peptide injections. In this way, we demonstrated effects of CRF/DH and NPF on several reproductive parameters in females and males (e.g. effects on oocyte growth, ecdysteroid titers, male sexual maturation). Taken together, our data show that the NPF and CRF/DH-OMP signaling systems are involved in the regulation of food intake, as well as in several physiological processes related to reproduction (and probably also related to the first effect). Based on these functions, these signaling systems may represent interesting targets for insect pest management.status: publishe

The Emergence of the Corporate Form

The Dutch East India Company (VOC) is generally viewed as the first modern corporation, yet its 1602 charter did not introduce all features of legal personality. A detailed historical analysis reveals how its statute proved inadequate to sustain the massive military investment needed to secure a strong trade position in Asia. In response, legal innovations were introduced in the subsequent twenty years. In 1612, state intervention overruled shareholder rights and created capital lock-in. The associated loss of control by shareholders was ultimately compensated by long-term profits, as the escalated commitment to Asia allowed the VOC to outperform its competitors. Once capital became permanent, VOC directors needed and gained the final corporate feature of general limited liability in 1623. We argue that this transition could be achieved while preserving private interests because the Dutch Republic’s limited form of government protected long term private capital, while autocratic colonial powers maintained a royal monopoly on colonial trade. The English East India Company adopted the much-admired Dutch model only half a century later, as the crown became subject to parliamentary control. By then the Dutch grip on South-East Asia had become entrenched, leading its competitors to focus elsewhere

Gaia Catalogue of Nearby Stars - GCNS

VizieR online Data Catalogue associated with article published in journal Astronomy &amp; Astrophysics with title 'Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars.' (bibcode: 2021A&amp;A...649A...6G