Search

PDF file - 40K

PDF file - 78K

PDF file - 77K

BackgroundThe role of the soluble urokinase plasminogen activator receptor (suPAR) in focal segmental glomerulosclerosis (FSGS) as the circulating factor or as a predictor of recurrence after transplantation remains controversial. Previously published studies in mice and isolated podocytes produced conflicting results on the effect of suPAR on podocyte injury, effacement of foot processes, and proteinuria. These discordant results were in part due to diverse experimental designs and different strains of mice. The aim of our study was to determine the reasons for the inconsistencies of the previous studies results with suPAR by using uniform methods and studies in different strains of mice.MethodsWe utilized a primary culture of human podocytes and 2 mouse models, the wild type (WT) and the urokinase plasminogen activator receptor (uPAR) KO (uPAR), in an attempt to resolve the reported conflicting results.ResultsIn both WT and uPAR mouse models, injection of recombinant uPAR, even at a high dose (100 μg), did not induce proteinuria, effacement of podocytes, or disruption of the cytoskeleton. Injection of suPAR resulted in its deposition exclusively in the glomerular endothelial cells and not in the podocytes of WT mice and was not detected at the uPAR KO mice. Kidneys from patients with recurrent FSGS had negative immunostaining for uPAR. We also evaluated the effect of recombinant uPAR on primary culture of human podocytes. uPAR did not result in podocytes damage.ConclusionssuPAR by itself is not the cause for direct podocyte injury, in vitro or in vivo. These findings suggest a more complex and still poorly understood role of suPAR in FSGS.

Author(s): Laquer, Vivian; Dellinger, Ryan W; Mannering, Irene; Garcia, Angela Gomez; Abraham, Vivek; Pavlis, Janelle; Liu-Smith, Feng; De Feraudy, Sebastien; Meyskens, Frank L; Kelly, Kristen M

Background We investigated circulating levels of individual soluble urokinase plasminogen activation receptor (suPAR) forms to determine if specific circulating fragments of suPAR (II-III) and (I) can better serve as clinical biomarkers for focal segmental glomerulosclerosis (FSGS) and the risk of recurrence after transplantation. Materials and methods Serum levels of intact suPAR and its cleaved forms were measured with two assays, ELISA and TR-FIA. Results suPAR levels in healthy controls were significantly lower than those who had glomerular diseases but were not significantly different between FSGS patients and glomerular controls. Intact suPAR (I-II-III) levels were noted to be elevated in glomerular diseases including FSGS. uPAR fragment (I) levels measured with the TR-FIA 4 assay were significantly higher in FSGS (695.4 + 91.29 pMol/L) than glomerular controls (239.1 + 40.45 pMol/L, P = 0.001). However, suPAR(I) levels were not significantly different between recurrent FSGS and nonrecurrent FSGS patients. Conclusion Our analysis of suPAR using the ELISA assay used in all previous studies does not appear to be a useful marker for FSGS nor serve as a predictor for its recurrence after transplantation. The TR-FIA assay results suggest that uPAR(I) is a potential biomarker for FSGS but not of its recurrence.

Author(s): Di, Kaijun; Lloyd, G Kenneth; Abraham, Vivek; MacLaren, Ann; Burrows, Francis J; Desjardins, Annick; Trikha, Mohit; Bota, Daniela A | Abstract: BackgroundThe proteasome plays a vital role in the physiology of glioblastoma (GBM), and proteasome inhibition can be used as a strategy for treating GBM. Marizomib is a second-generation, irreversible proteasome inhibitor with a more lipophilic structure that suggests the potential for penetrating the blood-brain barrier. While bortezomib and carfilzomib, the 2 proteasome inhibitors approved for treatment of multiple myeloma, have little activity against malignant gliomas in vivo, marizomib could be a novel therapeutic strategy for primary brain tumors.MethodsThe in-vitro antitumor activity of marizomib was studied in glioma cell lines U-251 and D-54. The ability of marizomib to cross the blood-brain barrier and regulate proteasome activities was evaluated in cynomolgus monkeys and rats. The antitumor effect of marizomib in vivo was tested in an orthotopic xenograft model of human GBM.ResultsMarizomib inhibited the proteasome activity, proliferation, and invasion of glioma cells. Meanwhile, free radical production and apoptosis induced by marizomib could be blocked by antioxidant N-acetyl cysteine. In animal studies, marizomib distributed into the brain at 30% of blood levels in rats and significantly inhibited (g30%) baseline chymotrypsin-like proteasome activity in brain tissue of monkeys. Encouragingly, the immunocompromised mice, intracranially implanted with glioma xenografts, survived significantly longer than the control animals (P l .05) when treated with marizomib.ConclusionsThese preclinical studies demonstrated that marizomib can cross the blood-brain barrier and inhibit proteasome activity in rodent and nonhuman primate brain and elicit a significant antitumor effect in a rodent intracranial model of malignant glioma.

e12644 Background: Glioblastoma (GBM) is a highly aggressive brain tumor which displays innate resistance to multiple treatment modalities. Previous studies have shown that the proteasome plays a v...

Bullous pemphigoid (BP) is a chronic autoimmune disease that mainly affects elderly patients. It presents as skin lesions; however, it can affect the eyes and upper aerodigestive system as well. We report a rare case of Bullous pemphigoid that had a laryngeal extension presenting with odynophagia.

Medaka (Oryzias latipes) eggs microinjected with the Ca2+-mobilising messenger cyclic adenosine diphosphate ribose (cADPR) underwent a wave of exocytosis of cortical alveoli and were thus activated. The number of eggs activated was sharply dependent on the concentration of cADPR in the pipette, the threshold concentration was approximately 60 nM. After injection, a pronounced latency preceded the onset of cortical alveoli exocytosis; this latency was independent of the concentration of cADPR but decreased markedly with increasing temperature. Heat-treated cADPR, which yields the inert non-cyclised product ADP-ribose, was ineffective in activating eggs. When cADPR was injected into aequorin-loaded eggs, a wave of luminescence arose at the site of cADPR injection and then swept out across the egg with a mean velocity of approximately 13 μm/s; the velocity was independent of the concentration of injected cADPR. In such a large cell (diameter of around 1 mm), this is considerably faster than that possible by simple diffusion of cADPR, which unambiguously demonstrates that cADPR must activate a regenerative process. cADPR has been demonstrated to modulate Ca2+-induced Ca2+ release (CICR) via ryanodine receptors (RyRs) in many cell types, and consistent with this was the finding that microinjection of the pharmacological RyR modulator, ryanodine, also activated medaka eggs. These results suggest that a cADPR-sensitive Ca2+ release mechanism is present in the medaka egg, that cADPR is the most potent activator of medaka eggs described to date, and that it activates eggs by triggering a wave of CICR from internal stores that in turn stimulates a wave of exocytosis.