CCL18 synergises with high concentrations of glucose in stimulating fibronectin production in human renal tubuloepithelial cells.

Background: Diabetic nephropathy is the leading cause of end stage kidney disease worldwide. The pathogenesis of this disease remains elusive and multiple factors have been implicated. These include the effects of hyperglycaemia, haemodynamic and metabolic factors, and an inflammatory process that stimulates cellular signalling pathways leading to disease progression and severe fibrosis. Fibronectin (Fn) is an important protein of the extracellular matrix that is essential in fibrosis and its presence in increased amounts has been identified in the kidney in diabetic nephropathy. Methods: Proximal tubuloepithelial (HK-2) cells were stimulated with high glucose (30mM D-glucose) or glycated albumin (500μg/mmol) + 4mM D-glucose or their controls, Mannitol (26mM+4mM D-glucose) and 4mM D-glucose, respectively. Following 48 hours of stimulation the supernatant was collected and MTT [3-(4,5-dimethylthiazole-2,5-diphenyltetrazolium bromide] assay performed to assess cell viability. HK-2 cells were also stimulated in the above environments with recombinant CCL18 (rCCL18) or MCP-1 (rMCP-1) for 48 hours with quantification of Fn levels using ELISA. Results: Co-stimulation of HK-2 cells with high concentrations of glucose and rCCL18 significantly increased Fn (p<0.001), in comparison to high concentrations of glucose alone. HK-2 cells stimulated with glycated albumin consistently produced Fn and this did not alter following co-stimulation with rCCL18 or rMCP-1. Conclusion: This study demonstrates how stimulation with a specific chemokine CCL18 in high glucose upregulates the production of Fn from proximal tubuloepithelial cells. This may be relevant to the development of renal fibrosis in diabetic nephropath

Maritime piracy: an auto-limitation approach

This study examines the problems we face in making a coherent theoretical link between the international law of piracy and the law of the sea in the context of the rise in maritime piracy in Africa over the past three decades. It focuses on four nations affected by piracy in the Gulf of Guinea and Horn of Africa. Furthermore, the international law of piracy is concerned with two types of jurisdiction: prescriptive jurisdiction and enforcement jurisdiction. However, the law of the sea (UN Law of the Sea Convention) defines five types of jurisdiction: territorial seas, exclusive economic zone (EEZ), the continental shelf, high seas, and seabed or seafloor outside the area of claims of territorial seas under the EEZ. The above implies that where a State that has enforcement jurisdiction is unable or unwilling to enforce prescribed international laws against piracy, recourse ought to be had to a State with jurisdiction under the law of the sea. The current thesis seeks to demonstrate that maritime piracy has substantially increased in north-eastern and western parts of Africa because, albeit the development of the law of the sea has transposed towards acknowledging the rights (and obligations) of coastal States in order to defend their territorial seas with reference to the piratical incursions, not enough attention has been given to the consequences flowing from the fact that the coastal states in question do not possess the requisite resources and systems to enforce international law and/ or prosecute pirates. It is submitted here that piracy in its modern form in the Gulf of Aden and Gulf of Guinea is a transnational crime that may best be contained through a regional legal infrastructure. It is also argued that the multilateral approach of linking enforcement jurisdiction to Universal Jurisdiction is problematic since it translates into ‘relational statism’ that is, where States habitually pursue only their self-interests. As such, consistency and clarity in the international legal situation may best be achieved by recourse to a traditional ‘auto-limitation’ approach whereby jurisdiction is essentially territorial and can only be exercised by a State outside its territory where it obtains the consent of the territorial State (perhaps through Convention or Treaty) or in accordance with a permissive rule derived from international custom. Therefore the thesis of this study suggests the need for legal reform. Chapter 1 provides the background to the study as well as the framework for the research. The main research aims, objectives and research questions are addressed in Chapters 2, 3, 4, 5 and 6. Chapter 7 concludes the research by presenting the findings and recommendations together with an outline of the research contribution

Exaggerated renal fibrosis in P2X4 receptor-deficient mice following unilateral ureteric obstruction

Background The ATP-sensitive P2X7 receptor (P2X7R) has been shown to contribute to renal injury in nephrotoxic nephritis, a rodent model of acute glomerulonephritis, and in unilateral ureteric obstruction (UUO), a rodent model of chronic interstitial inflammation and fibrosis. Renal tubular cells, endothelial cells and macrophages also express the closely related P2X4 receptor (P2X4R), which is chromosomally co-located with P2X7R and has 40% homology; it is also pro-inflammatory and has been shown to interact with P2X7R to modulate its pro-apoptotic and pro-inflammatory effects. Therefore, we chose to explore the function of P2X4R in the UUO model of renal injury using knockout mice. We hypothesized that UUO-induced tubulointerstitial damage and fibrosis would also be attenuated in P2X4R−/− mice. Method P2X4R−/− and wild-type (WT) mice were subjected to either UUO or sham operation. Kidney samples taken on Days 7 and 14 were evaluated for renal inflammation and fibrosis, and expression of pro-fibrotic factors. Results To our surprise, the obstructed kidney in P2X4R−/− mice showed more severe renal injury, more collagen deposition (picrosirius red staining, increase of 53%; P < 0.05) and more type I collagen staining (increase of 107%; P < 0.01), as well as increased mRNA for TGF-β (increase of 102%, P < 0.0005) and CTGF (increase of 157%; P < 0.05) by Day 14, compared with the UUO WT mice. Conclusion These findings showed that lack of P2X4R expression leads to increased renal fibrosis, and increased expression of TGF-β and CTGF in the UUO mode

Characterisation of an enhanced preclinical model of experimental MPO-ANCA autoimmune vasculitis

Experimental autoimmune vasculitis (EAV) is a model of antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) induced by immunisation of susceptible rat strains with myeloperoxidase (MPO). Animals develop circulating MPO-ANCA, pulmonary haemorrhage and glomerulonephritis, although renal injury is mild and recovers spontaneously without treatment. In this study we aimed to augment the severity of glomerulonephritis. Following induction of EAV on day 0, a sub-nephritogenic dose of nephrotoxic serum (NTS) containing heterologous antibodies to glomerular basement membrane was administered on day 14. This resulted in a significant increase in disease severity at day 28 compared to MPO immunisation alone - with more urinary abnormalities, infiltrating glomerular leucocytes, and crescent formation that progressed to glomerular and tubulointerstitial scarring by day 56, recapitulating important features of human disease. Importantly, the glomerulonephritis remained pauci-immune, and was strictly dependent on the presence of autoimmunity to MPO, as there was no evidence of renal disease following administration of sub-nephritogenic NTS alone or after immunisation with a control protein in place of MPO. Detailed phenotyping of glomerular leucocytes identified an early infiltrate of non-classical monocytes following NTS administration that, in the presence of autoimmunity to MPO, may initiate the subsequent influx of classical monocytes which augment glomerular injury. We also showed that this model can be used to test novel therapeutics by using a small molecule kinase inhibitor (fostamatinib) that rapidly attenuated both glomerular and pulmonary injury over a four-day treatment period. We believe that this enhanced model of MPO-AAV will prove useful for the study of glomerular leucocyte behaviour and novel therapeutics in AAV in the future. This article is protected by copyright. All rights reserved

Involuntary Entry Into Consciousness From the Activation of Sets: Object Counting and Color Naming

High-level cognitions can enter consciousness through the activation of certain action sets and the presentation of external stimuli (“set-based entry,” for short). Set-based entry arises in a manner that is involuntary and systematic. In the Reflexive Imagery Task, for example, subjects are presented with visual objects and instructed to not think of the names of the objects. Involuntary subvocalizations arise on roughly 80% of the trials. We examined whether or not set-based entry can also occur in the case of involuntary counting. Subjects in Experiment 1A were instructed to not count the number of objects presented in an array. Involuntary counting arose on a high proportion of the trials (a mean proportion of ∼0.90) for stimulus arrays having 2–5 objects, and such counting arose less frequently across trials when the array consisted of 6–10 objects (a mean proportion of ∼0.21). The data from Experiment 1B revealed that, when people choose to perform Set X, they also experience thoughts about an unselected Set (Set Y). Subjects were trained on one set (e.g., to “color name”) and then, when presented with stimuli, were given the choice to perform the trained set or a novel set. Consistent with theories proposing that the conscious contents represent several potential action plans, subjects were equally likely to experience set-related imagery or set-unrelated imagery. Our findings regarding set-based entry are relevant to many subfields of psychology and neuroscience (e.g., the study of high-level mental processes, attention, imagery, and action control)

P2X7 receptor‐mediated Nlrp3‐inflammasome activation is a genetic determinant of macrophage‐dependent crescentic glomerulonephritis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141169/1/jlb0127-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141169/2/jlb0127.pd

Binding Truths: Atypical anti-GBM disease mediated by IgA anti-GBM antibodies targeting the α1 chain of type IV collagen

Anti−glomerular basement membrane (anti-GBM) disease presents with rapidly progressive glomerulonephritis, often associated with alveolar hemorrhage and characterized histologically by crescentic glomerulonephritis. Typically, there is linear deposition of Ig along the glomerular basement membrane (GBM), which, in the majority of cases, is due to IgG autoantibodies directed against the noncollagenous domain of the α3 chain of type IV collagen (α3[IV]NC1).1 Early disease recognition relies on detecting circulating IgG anti-GBM antibodies in serum samples. However, conventional assays do not detect IgA antibodies or those directed against other target antigens, including α5(IV) found in some Alport disease patients following renal transplantation.2 The presence and specificity of the antibody can be confirmed by Western blotting, usually at a reference center, although this is not routinely performed. We describe a case of anti-GBM disease mediated by IgA anti-GBM antibodies not detected by standard serological tests, and suggest a method of detection and monitoring that can be used in the right clinical context

Randomized Trial on the Effect of an Oral Spleen Tyrosine Kinase Inhibitor in the Treatment of IgA Nephropathy

Introduction: We reported increased spleen tyrosine kinase (SYK) expression in kidney biopsies of patients with IgA nephropathy (IgAN) and that inhibition of SYK reduces inflammatory cytokines production from IgA stimulated mesangial cells. / Methods: This study was a double-blind, randomized, placebo-controlled phase 2 trial of fostamatinib (an oral SYK inhibitor) in 76 patients with IgAN. Patients were randomized to receive placebo, fostamatinib at 100 mg or 150 mg twice daily for 24 weeks on top of maximum tolerated dose of renin-angiotensin system inhibitors. The primary end point was reduction of proteinuria. Secondary end points included change from baseline in estimated glomerular filtration rate (eGFR) and kidney histology. / Results: Although we could not detect significant reduction in proteinuria with fostamatinib overall, in a predetermined subgroup analysis, there was a trend for dose-dependent reduction in median proteinuria (from baseline to 24 weeks by 14%, 27%, and 36% in the placebo, fostamatinib 100 mg, and 150 mg groups, respectively) in patients with baseline urinary protein-to-creatinine ratios (UPCR) more than 1000 mg/g. Kidney function (eGFR) remained stable in all groups. Fostamatinib was well-tolerated. Side effects included diarrhea, hypertension, and increased liver enzymes. Thirty-nine patients underwent repeat biopsy showing reductions in SYK staining associated with therapy at low dose (−1.5 vs. 1.7 SYK+ cells/glomerulus in the placebo group, P < 0.05). / Conclusions: There was a trend toward reduction in proteinuria with fostamatinib in a predefined analysis of high risk patients with IgAN despite maximal care, as defined by baseline UPCR greater than 1000 mg/g. Further study may be warranted