scholarly journals Human Mesangial Cells in Culture and in Kidney Sections Fail to Express Fc Alpha Receptor (CD89)

1999 ◽  
Vol 10 (4) ◽  
pp. 770-778
Author(s):  
RALF WESTERHUIS ◽  
GER VAN ZANDBERGEN ◽  
NICOLE A. M. VERHAGEN ◽  
N. KLAR-MOHAMAD ◽  
MOHAMED R. DAHA ◽  
...  
Keyword(s):  
Iga Nephropathy ◽  
Mesangial Cells ◽  
Polyclonal Antibodies ◽  
Membrane Receptors ◽  
Dependent Manner ◽  
Significant Extent ◽  
Human Mesangial Cells ◽  
Reverse Transcription Pcr ◽  
Dose Dependent

Abstract. The mechanism of deposition of IgA in the renal mesangium in primary IgA-nephropathy is poorly understood. It has been suggested that membrane receptors for IgA on mesangial cells (MC) of the kidney may be involved. To obtain more insight in the occurrence of the myeloid receptor for IgA (CD89) on MC, both in situ and in culture, rabbit and goat polyclonal antibodies and mouse monoclonal antibody against recombinant CD89 were raised. Kidney sections from five control subjects and five patients with primary IgA-nephropathy failed to be positive for CD89 in the mesangium, using our polyclonal and monoclonal antibodies. Also, five primary human MC cultures assessed for CD89 expression showed no protein expression of CD89. Furthermore, reverse transcription-PCR failed to detect mRNA expression of CD89 in the cultured MC. It was demonstrated that all five human primary MC bound human IgA in a dose-dependent manner, which was not inhibitable by blocking monoclonal anti-CD89 antibody (My43). In contrast, binding of IgA to U937 cells was blocked efficiently by My43. Finally, incubation of human MC with either human or rat IgA led to increased interleukin-6 production, whereas only human IgA, but not rat IgA, was able to bind to human CD89. Therefore, it is concluded that human MC do not express CD89 (to a significant extent). These results strongly suggest that binding of IgA to human MC occurs via an IgA receptor distinct from CD89.

Detection of α1 Integrin in Urine of Patients With Immunoglobulin A Nephropathy

2008 ◽  
Vol 56 (3) ◽  
pp. 581-586
Author(s):  
Jonathan Bank ◽  
Aharon Ben-David ◽  
Ram Doolman ◽  
Ben-Ami Sela ◽  
Ilan Bank
Keyword(s):  
Mesangial Cells ◽  
Kidney Diseases ◽  
Surface Membrane ◽  
Immunoglobulin A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Healthy Individuals ◽  
Immunoglobulin A Nephropathy ◽  
A Cell ◽  
Dose Dependent

BackgroundThe α1β1 integrin is a cell surface membrane heterodimer composed of noncovalently linked α1 and β1 polypeptides that is up-regulated on activated and proliferating mesangial cells.MethodsA double-sandwich enzyme-linked immunosorbent assay that detects α1 integrin in a specific and dose-dependent manner at concentrations greater than 150 ng/mL was used to evaluate whether intact α1 polypeptides are secreted in the urine samples of 29 patients with various kidney diseases and in those of 5 healthy individuals.Resultsα1 Integrin was detected in 8 of the 29 patients including 3 of 3 patients with biopsy-proven immunoglobulin A nephropathy and 3 of 3 clinically suspected but non-biopsy-proven immunoglobulin A nephropathy with evidence of active nephritis. No α1 integrins were found in samples of 5 healthy controls.Conclusionsα1 Integrin polypeptides can be detected in human urine, particularly in immunoglobulin A nephropathy. Further extensive studies are required to clarify the significance of secretion of α1 integrins in urine of patients with kidney disease.

scholarly journals Purification and some properties of the 45 kDa diphenylene iodonium-binding flavoprotein of neutrophil NADPH oxidase

1990 ◽  
Vol 265 (1) ◽  
pp. 95-100 ◽  
Author(s):  
C M Yea ◽  
A R Cross ◽  
O T G Jones
Keyword(s):  
Polyclonal Antibodies ◽  
Specific Inhibitor ◽  
Small Subunit ◽  
Dependent Manner ◽  
Superoxide Generation ◽  
Diaphorase Activity ◽  
Low Concentrations ◽  
Diphenylene Iodonium ◽  
Neutrophil Superoxide ◽  
Dose Dependent

The 45 kDa diphenylene iodonium-binding flavoprotein of the human neutrophil superoxide-generating oxidase has been purified by affinity chromatography. The polypeptide was eluted from Blue Memsep or 2′,5′-ADP-agarose columns with either NADP or low concentrations of the specific inhibitor diphenylene iodonium. The purified protein was shown to bind FAD at a ratio of 1.09 mol of FAD/mol of protein. The reconstituted flavoprotein had a fluorescence spectrum similar, but not identical, to that of free FAD. It had an isoelectric point of approx. 4.0. The reconstituted flavoprotein displayed no diaphorase activity towards a range of artificial electron acceptors. Polyclonal antibodies raised against the pure protein inhibited superoxide generation by solubilized oxidase in a dose-dependent manner, and inhibited superoxide generation when incubated with either cytosol or membrane fractions in a reconstituted system. These antibodies precipitated the 45 kDa polypeptide together with a haem-containing 23 kDa protein thought to be the small subunit of cytochrome b-245. Antibodies raised against cytochrome P-450 reductase also precipitated these two polypeptides. These results are consistent with the 45 kDa polypeptide being the flavoprotein of the neutrophil superoxide-generating oxidase.

Determination of mosquito bloodmeal pH in situ by ion-selective microelectrode measurement: implications for the regulation of malarial gametogenesis

Parasitology ◽  
2000 ◽  
Vol 120 (6) ◽  
pp. 547-551 ◽  
Author(s):  
O. BILLKER ◽  
A. J. MILLER ◽  
R. E. SINDEN
Keyword(s):  
Xanthurenic Acid ◽  
Mosquito Vector ◽  
Dependent Manner ◽  
Ph Increase ◽  
Ph Range ◽  
Dose Dependent

Malarial gametocytes circulate in the peripheral blood of the vertebrate host as developmentally arrested intra-erythrocytic cells, which only resume development into gametes when ingested into the bloodmeal of the female mosquito vector. The ensuing development encompasses sexual reproduction and mediates parasite transmission to the insect. In vitro the induction of gametogenesis requires a drop in temperature and either a pH increase from physiological blood pH (ca pH 7·4) to about pH 8·0, or the presence of a gametocyte-activating factor recently identified as xanthurenic acid (XA). However, it is unclear whether either the pH increase or XA act as natural triggers in the mosquito bloodmeal. We here use pH-sensitive microelectrodes to determine bloodmeal pH in intact mosquitoes. Measurements taken in the first 30 min after ingestion, when malarial gametogenesis is induced in vivo, revealed small pH increases from 7·40 (mouse blood) to 7·52 in Aedes aegypti and to 7·58 in Anophěles stephensi. However, bloodmeal pH was clearly suboptimal if compared to values required to induce gametogenesis in vitro. Xanthurenic acid is shown to extend the pH-range of exflagellation in vitro in a dose-dependent manner to values that we have observed in the bloodmeal, suggesting that in vivo malarial gametogenesis could be further regulated by both these factors.

scholarly journals IgA1 immune complexes from pediatric patients with IgA nephropathy activate cultured human mesangial cells

2011 ◽  
Vol 26 (11) ◽  
pp. 3451-3457 ◽  
Author(s):  
Jan Novak ◽  
Leona Raskova Kafkova ◽  
Hitoshi Suzuki ◽  
Milan Tomana ◽  
Karel Matousovic ◽  
...  
Keyword(s):  
Iga Nephropathy ◽  
Immune Complexes ◽  
Pediatric Patients ◽  
Mesangial Cells ◽  
Human Mesangial Cells

Cloning and expression of a functional rat liver D-β-hydroxybutyrate dehydrogenase-β-galactosidase fusion protein in Escherichia coli

1991 ◽  
Vol 69 (9) ◽  
pp. 670-673
Author(s):  
Sharon Churchill ◽  
Perry Churchill
Keyword(s):  
Escherichia Coli ◽  
Rat Liver ◽  
Polyclonal Antibodies ◽  
Cloning And Expression ◽  
Dependent Manner ◽  
Bacteriophage Λ ◽  
Expression Library ◽  
Expression Plasmid ◽  
E Coli ◽  
Dose Dependent

A rat liver bacteriophage λ expression library was probed using polyclonal antibodies raised to purified rat liver D-β-hydroxybutyrate dehydrogenase (BDH). A clone was selected that contained a 1.2-kb insert. The insert placed in an expression plasmid was utilized to transform Escherichia coli. These cells were shown to possess phosphatidylcholine-dependent BDH activity. Cells transformed with only the plasmid had no detectable BDH activity in the presence of phosphatidylcholine. The expressed activity in E. coli could be inhibited in a dose-dependent manner by BDH antiserum.Key words: D-β-hydroxybutyrate dehydrogenase, cloning, expression.

c-Jun NH2-terminal kinase mediation of angiotensin II-induced proliferation of human mesangial cells

2005 ◽  
Vol 288 (6) ◽  
pp. F1118-F1124 ◽  
Author(s):  
Aihua Zhang ◽  
Guixia Ding ◽  
Songming Huang ◽  
Yuanjun Wu ◽  
Xiaoqing Pan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Angiotensin Ii ◽  
Map Kinases ◽  
Mesangial Cells ◽  
Cell Number ◽  
Renal Diseases ◽  
Steady Increase ◽  
Dependent Manner ◽  
Ang Ii ◽  
Human Mesangial Cells

Angiotensin II (ANG II) has been shown to activate c-Jun NH2-terminal kinase (JNK) in cultured mesangial cells, but the functional implication of this phenomenon remains to be determined, largely due to the lack of an effective approach to block JNK. Therefore, the present study was carried out to examine whether JNK is involved in ANG II-induced cell proliferation in cultured human mesangial cells (HMCs) with the use of a newly developed JNK-selective blocker, SP-600125. Within minutes, treatment with 100 nM ANG II activated all three members of MAP kinase family, including extracellular signal-regulated protein kinase (Erk) 1/2, JNK, and p38 in cultured HMCs, as assessed by immunoblotting detection of phosphorylation of MAP kinases. ANG II-dependent activation of JNK was further confirmed by detection of increased phosphorylation and transcription activity of c-Jun after the ANG II treatment. SP-600125 ranging from 5 to 10 μM almost completely abolished the activation of JNK by ANG II without affecting the activities of Erk1/2 and p38. After treatment with 100 ng ANG II, there was a steady increase in [3H]thymidine incorporation that was blocked by SP-60025 in a dose- and time-dependent manner. Similarly, SP-600125 dose dependently reduced the ANG II-induced increase in cell number. The antiproliferative effect of SP-60025 was further determined by cell-cycle analysis with flow cytometry. Twenty-four hours after ANG II treatment, 50% of the quiescent HMCs (G0/G1) progressed into the S phase, and the cell cycle progression was almost completely prevented in the presence of SP-60025. Our data suggest that JNK mediates the proliferative effect of ANG II in cultured HMCs and thus represents a novel therapeutic target for treatment of chronic renal diseases.

scholarly journals In-Vivo Toxicity Studies and In-Vitro Inactivation of SARS-CoV-2 by Povidone-iodine In-situ Gel Forming Formulations

2020 ◽  
Author(s):  
Bo Liang ◽  
Xudong Yuan ◽  
Gang Wei ◽  
Wei Wang ◽  
Ming Zhang ◽  
...  
Keyword(s):  
Povidone Iodine ◽  
Early Stage ◽  
Etiologic Agent ◽  
Dependent Manner ◽  
Forming Technology ◽  
Long Acting ◽  
Dose Dependent

AbstractTo curb the spread of SARS-CoV-2, the etiologic agent of the COVID-19 pandemic, we characterize the virucidal activity of long-acting Povidone Iodine (PVP-I) compositions developed using an in-situ gel forming technology. The PVP-I gel forming nasal spray (IVIEW-1503) and PVP-I gel forming ophthalmic eye drop (IVIEW-1201) rapidly inactivated SARS-CoV-2, inhibiting the viral infection of VERO76 cells. No toxicity was observed for the PVP-I formulations. Significant inactivation was noted with preincubation of the virus with these PVP-I formulations at the lowest concentrations tested. It has been demonstrated that both PVP-I formulations can inactivate SARS-CoV-2 virus efficiently in both a dose-dependent and a time-dependent manner. These results suggest IVIEW-1503 and IVIEW-1201 could be potential agents to reduce or prevent the transmission of the virus through the nasal cavity and the eye, respectively. Further studies are needed to clinically evaluate these formulations in early-stage COVID-19 patients.

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