Mass spectrometry-based circulating IgA1 complexes screening driven identification of IgA-alpha-1-microglobulin complex in IgA nephropathy

2020 ◽  
Author(s):  
Boyang Xu ◽  
Li Zhu ◽  
Qingsong Wang ◽  
Yanfeng Zhao ◽  
Meng Jia ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Iga Nephropathy ◽  
Cell Injury ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Independent Population ◽  
Tubulointerstitial Lesions ◽  
Noninvasive Biomarker

Abstract Background IgA nephropathy (IgAN) is characterized by predominant IgA deposition in the glomerular mesangium. Previous studies proved that renal-deposited IgA in IgAN came from circulating IgA1-containing complexes (CICs). Methods To explore the composition of CICs in IgAN, we isolated CICs from IgAN patients and healthy controls, and then quantitatively analyzed them by mass spectrometry. Meanwhile, the isolated CICs were used to treat human mesangial cells to monitor mesangial cell injury. Taken together the proteins content and injury effects, the key constituent in CICs was identified. Then, the circulating levels of identified key constituent-IgA complex were detected in an independent population by an in-house-developed ELISA. Results By comparing the proteins of CICs between IgAN patients and controls, we found that 14 proteins showed significantly different levels. Among them, alpha-1-microglobulin content in CICs was associated with not only in vitro mesangial cell proliferation and MCP-1 secretion but also in vivo eGFR levels and tubulointerstitial lesions in IgAN patients. Moreover, we found alpha-1-microglobulin was prone to bind aberrant glycosylated IgA1. Additionally, an elevated circulating IgA-alpha-1-microglobulin complex levels were detected in an independent IgAN population, and IgA-alpha-1-microglobulin complex levels were correlated with hypertension, eGFR levels and Oxford-T scores in these IgAN patients. Conclusions Our results suggest that the IgA-alpha-1-microglobulin complex is an important constituent in CICs, and that circulating IgA-alpha-1-microglobulin complex detection might serve as a potential noninvasive biomarker detection method for IgAN.

scholarly journals Endothelium-derived relaxing factor, nitric oxide: effects on and production by mesangial cells and the glomerulus.

1993 ◽  
Vol 3 (8) ◽  
pp. 1435-1441
Author(s):  
L Raij ◽  
P J Shultz
Keyword(s):  
Nitric Oxide ◽  
Vascular Tone ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Glomerular Mesangial Cells ◽  
Relaxing Factor ◽  
Endothelium Derived Relaxing Factor

The endothelium-derived relaxing factor nitric oxide (EDRF/NO) is a labile, endogenous vasodilator that is important in the control of systemic vascular tone. This review focuses on the effects of EDRF/NO on glomerular mesangial cells in vitro and on the role of EDRF/NO in mesangial and glomerular physiology and pathophysiology in vivo. It was concluded that EDRF/NO can stimulate increases in cGMP, inhibit mesangial cell contraction, and inhibit growth factor-induced proliferation of mesangial cells in culture. Furthermore, incubation with endotoxin or cytokines stimulates mesangial cells to produce EDRF/NO, via an inducible NO synthase enzyme. Therefore, it is likely that NO could play a role in the inflammatory response within the glomerulus. Finally, recent studies providing evidence that EDRF/NO is functional within the glomerulus in vivo, especially during endotoxemia and inflammation are also reviewed.

Activation of podocytes by mesangial-derived TNF-α: glomerulo-podocytic communication in IgA nephropathy

2008 ◽  
Vol 294 (4) ◽  
pp. F945-F955 ◽  
Author(s):  
Kar Neng Lai ◽  
Joseph C. K. Leung ◽  
Loretta Y. Y. Chan ◽  
Moin A. Saleem ◽  
Peter W. Mathieson ◽  
...  
Keyword(s):  
Iga Nephropathy ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Neutralizing Antibody ◽  
Important Mediator ◽  
Tnf Α ◽  
Strategic Position ◽  
Inflammatory Changes

We have previously documented that human mesangial cell (HMC)-derived TNF-α is an important mediator involved in the glomerulo-tubular communication in the development of interstitial damage in IgA nephropathy (IgAN). With the strategic position of podocytes, we further examined the role of mesangial cells in the activation of podocytes in IgAN. There was no binding of IgA from patients with IgAN to podocytes. Podocytes cultured with IgA from patients with IgAN did not induce the release of growth factors or cytokines. Furthermore, podocytes did not express mRNA of known IgA receptors. In contrast, IgA-conditioned medium (IgA-HMC medium) prepared by culturing HMC with IgA from patients with IgAN for 48 h significantly increased the gene expression and protein synthesis of TNF-α by podocytes with a 17-fold concentration above that of IgA-HMC medium. The upregulation of TNF-α expression by podocyte was only abolished by a neutralizing antibody against TNF-α but not by other antibodies. Exogenous TNF-α upregulated the synthesis of TNF-α by podocytes in an autocrine fashion. IgA-HMC medium prepared with IgA from patients with IgAN also significantly upregulated the expression of both TNF-α receptor 1 and 2 in podocytes. Our in vitro finding suggests podocytes may play a contributory role in the development of interstitial damage in IgAN by amplifying the activation of tubular epithelial cells with enhanced TNF-α synthesis after inflammatory changes of HMC.

scholarly journals Dietary Chrysin Suppresses Formation of Actin Cytoskeleton and Focal Adhesion in AGE-Exposed Mesangial Cells and Diabetic Kidney: Role of Autophagy

Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 127 ◽  
Author(s):  
Eun-Jung Lee ◽  
Min-Kyung Kang ◽  
Yun-Ho Kim ◽  
Dong Yeon Kim ◽  
Hyeongjoo Oh ◽  
...  
Keyword(s):  
Cell Motility ◽  
Focal Adhesion ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Smooth Muscle Actin ◽  
Actin Dynamics ◽  
Chronic Glomerulonephritis ◽  
Causative Role

Advanced glycation end products (AGE) play a causative role in the development of aberrant phenotypes of intraglomerular mesangial cells, contributing to acute/chronic glomerulonephritis. The aim of this study was to explore mechanistic effects of the flavonoid chrysin present in bee propolis and herbs on actin dynamics, focal adhesion, and the migration of AGE-exposed mesangial cells. The in vitro study cultured human mesangial cells exposed to 33 mM glucose and 100 μg/mL AGE-bovine serum albumin (AGE-BSA) for up to 5 days in the absence and presence of 1–20 μM chrysin. The in vivo study employed db/db mice orally administrated for 10 weeks with 10 mg/kg chrysin. The presence of ≥10 μM chrysin attenuated mesangial F-actin induction and bundle formation enhanced by AGE. Chrysin reduced the mesangial induction of α-smooth muscle actin (α-SMA) by glucose, and diminished the tissue α-SMA level in diabetic kidneys, indicating its blockade of mesangial proliferation. The treatment of chrysin inhibited the activation of vinculin and paxillin and the induction of cortactin, ARP2/3, fascin-1, and Ena/VASP-like protein in AGE-exposed mesangial cells. Oral administration of chrysin diminished tissue levels of cortactin and fascin-1 elevated in diabetic mouse kidneys. Mesangial cell motility was enhanced by AGE, which was markedly attenuated by adding chrysin to cells. On the other hand, chrysin dampened the induction of autophagy-related genes of beclin-1, LC3 I/II, Atg3, and Atg7 in mesangial cells exposed to AGE and in diabetic kidneys. Furthermore, chrysin reduced the mTOR activation in AGE-exposed mesangial cells and diabetic kidneys. The induction of mesangial F-actin, cortactin, and fascin-1 by AGE was deterred by the inhibition of autophagy and mTOR. Thus, chrysin may encumber diabetes-associated formation of actin bundling and focal adhesion and mesangial cell motility through disturbing autophagy and mTOR pathway.

scholarly journals Catecholamines production by kidney tissue and mesangial cell culture is differentially modulated by diabetes

2021 ◽  
Author(s):  
Roseli Peres Moreira ◽  
Nadia S. C. Bertoncello ◽  
Juliana Almada Colucci ◽  
Danielle Yuri Arita ◽  
Maria Claudina Camargo de Andrade ◽  
...  
Keyword(s):  
Cell Culture ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Kidney Tissue ◽  
International Diabetes Federation ◽  
Sharp Decrease ◽  
Diabetic Rats ◽  
Control Group

Abstract Introduction: According to the International Diabetes Federation, the number of people with diabetes mellitus may reach 700 million in 2045. Catecholamines are involved in the regulation of several kidney functions. This study investigates the effects of hyperglycemia on catecholamines' metabolism in kidney tissue from control, diabetic, and insulin-treated diabetic rats, both in vivo and in vitro. Methods: Male Wistar-Hannover rats were randomized into: control, diabetic, and insulin-treated diabetic groups. Diabetes was induced by a single injection of streptozotocin, and diabetic treated group also received insulin. After 60 days, blood and kidney tissue from all groups were collected for catecholamines' quantification and mesangial cells culture. Results: diabetic rats had lower body weight, hyperglycemia, and increase water intake and diuresis. Additionally, diabetes promoted a sharp decrease in creatinine clearance compared to control group. Regarding the whole kidney extracts, both diabetic groups (treated and non-treated) had significant reduction in norepinephrine concentration. In mesangial cell culture, catecholamines' concentration were lower in the culture medium than in the intracellular compartment for all groups. Norepinephrine, epinephrine, and dopamine medium levels were increased in the diabetic group. Conclusion: The major finding of the present study was that 8 weeks of diabetes induction altered the kidney catecholaminergic system in a very specific manner, once the production of catecholamines in the excised kidney tissue from diabetic rats was differentially modulated as compared with the production and secretion by cultured mesangial cells.

scholarly journals Rat mesangial cells express macrophage migration inhibitory factor in vitro and in vivo.

1998 ◽  
Vol 9 (3) ◽  
pp. 417-424
Author(s):  
G H Tesch ◽  
D J Nikolic-Paterson ◽  
C N Metz ◽  
W Mu ◽  
M Bacher ◽  
...  
Keyword(s):  
Growth Factor ◽  
Macrophage Migration Inhibitory Factor ◽  
Mesangial Cell ◽  
De Novo ◽  
Mesangial Cells ◽  
Macrophage Migration ◽  
Mrna And Protein Expression ◽  
Macrophage Accumulation

Mesangial cells are thought to promote glomerular macrophage accumulation in glomerulonephritis. This may occur through the production of macrophage migration inhibitory factor (MIF), a molecule known to regulate macrophage accumulation at sites of inflammation. To study this, glomerular MIF expression and macrophage accumulation were examined in rat anti-Thy-1 disease, a model of mesangioproliferative nephritis. In situ hybridization and immunohistochemistry showed that MIF is expressed by some podocytes in normal rat glomeruli. De novo MIF expression by glomerular endothelium was seen on day 1 of anti-Thy-1 disease. On day 6, glomerular MIF mRNA and protein expression were prominent in segmental proliferative lesions, which was also the location of most infiltrating macrophages. Double-staining identified de novo MIF mRNA and protein expression by proliferating mesangial cells within these lesions. Cytokine regulation of mesangial cell MIF expression was examined in vitro. Northern blotting showed that cultured rat mesangial cells express a single 0.6-kb species of MIF mRNA, and Western blotting detected a single protein band of 12.5 kD. Six-hour stimulation of mesangial cells with interferon-gamma or platelet-derived growth factor significantly increased MIF mRNA levels. However, the addition of recombinant MIF to mesangial cells did not affect mesangial cell proliferation or constitutive transforming growth factor-beta mRNA expression, nor did MIF induce monocyte chemoattractant protein-1 mRNA expression. In conclusion, this is the first study to demonstrate that mesangial cells can produce MIF in vivo and in vitro. It is postulated that mesangial cell MIF production in response to injury acts to promote macrophage accumulation within segmental proliferative lesions in rat anti-Thy-1 nephritis.

scholarly journals Macromolecular properties that promote mesangial binding and mesangiopathic nephritis.

1992 ◽  
Vol 2 (10) ◽  
pp. S149 ◽  
Author(s):  
S N Emancipator ◽  
C S Rao ◽  
A Amore ◽  
R Coppo ◽  
J G Nedrud
Keyword(s):  
Cell Surface ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Sendai Virus ◽  
Cell Metabolism ◽  
Immunoglobulin A ◽  
Cross Linking ◽  
The Matrix

The hydrodynamic size, electrostatic charge, and specificity are established determinants of the site of glomerular localization of macromolecules. Larger macromolecules or aggregates and anionic charge are associated with mesangial deposits, despite the fact that the mesangial matrix bears a negative charge similar to that of the capillary wall. Antigens such as Sendai virus, a model infectious pathogen, gliadin, a model dietary/environmental agent and fibronectin, a model endogenous macromolecule, bind to mesangial cells in vitro on the basis of cell surface glycoconjugates. Nonantibody immunoglobulin A, which does not bind to cells directly, binds to these elements via different carbohydrate specificities (simple sugar inhibition). Such binding promotes or augments macromolecular deposition in the mesangium. More significantly, mesangial deposits per se are not pathogenic, because normal renal function can be observed with florid deposits. Pathogenic deposits must have properties that alter mesangial cell metabolism or interaction with the matrix. Although complement activation is well recognized, complement-independent mechanisms related to cell surface modulation are being recognized. In vitro, antigen/immunoglobulin A aggregates alter mesangial cell eicosanoid synthesis. In vivo, large-lattice cross-linking by particulate antigen promotes hematuria. We conclude that the binding of macromolecules to cells and the cross-linking of cell surface molecules cause alterations in the mesangial cells and therefore in glomerular function. The mesangial cell, rather than a passive respondent, is an active participant in the genesis of glomerulonephritis.

Identification of novel α-gliadin genes

Genome ◽  
2011 ◽  
Vol 54 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Peng-Fei Qi ◽  
Yu-Ming Wei ◽  
Qing Chen ◽  
Thérèse Ouellet ◽  
Jia Ai ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Triticum Aestivum L ◽  
Protein Band ◽  
Cysteine Residues ◽  
Disulphide Bonds ◽  
Chain Extenders ◽  
Domain I ◽  
Unique Domain

Ten novel α-gliadin genes (Gli-ta, Gli-turg1, Gli-turg2, Gli-turg3, Gli-turg4, Gli-turg5, Gli-turg6, Gli-cs1, Gli-cs2, and Gli-cs3) with unique characteristics were isolated from wheat ( Triticum aestivum L.), among which Gli-cs1, Gli-cs2, Gli-cs3, and Gli-turg6 were pseudogenes. Gli-cs3 and nine other sequences were much larger and smaller, respectively, than the typical α-gliadins. This variation was caused by insertion or deletion of the unique domain I and a polyglutamine region, possibly the result of illegitimate recombination. Consequently, Gli-cs3 contained 10 cysteine residues, whereas there were 2 cysteine residues only in the other nine sequences. Gli-ta/Gli-ta-like α-gliadin genes are normally expressed during the development of seeds. SDS–PAGE analysis showed that in-vitro-expressed Gli-ta could form intermolecular disulphide bonds and could be chain extenders. A protein band similar in size to Gli-ta has been observed in seed extracts, and mass spectrometry results confirm that the band contains small molecular mass α-gliadins, which is a characteristic of the novel α-gliadins. Mass spectrometry results also indicated that the two cysteine residues of Gli-ta/Gli-ta-like proteins participated in the formation of intermolecular disulphide bonds in vivo.

scholarly journals Anti-angiogenic compound (TNP-470) inhibits mesangial cell proliferation in vitro and in vivo

1997 ◽  
Vol 51 (6) ◽  
pp. 1838-1846 ◽  
Author(s):  
Masashi Haraguchi ◽  
Mikio Okamura ◽  
Masayo Konishi ◽  
Yoshio Konishi ◽  
Nobuo Negoro ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mesangial Cell ◽  
Mesangial Cell Proliferation ◽  
Proliferation In Vitro

scholarly journals Insulin induces rapid and specific rearrangement of the cytoskeleton of rat mesangial cells in vitro.

1996 ◽  
Vol 44 (2) ◽  
pp. 91-101 ◽  
Author(s):  
A K Berfield ◽  
G J Raugi ◽  
C K Abrass
Keyword(s):  
Mesangial Cells ◽  
Focal Adhesions ◽  
Cytoskeletal Proteins ◽  
Direct Effects ◽  
Ligand Effects ◽  
Igf I ◽  
Induced Changes ◽  
Secondary Ligand

Mesangial cells (MCs) grown without supplemental insulin (SI-MCs) express a quiescent phenotype and extracellular matrix (ECM) composition similar to MCs in vivo. In contrast, MCs routinely propagated in insulin (SI+MCs) are stimulated to proliferate, change their phenotype, and produce large amounts of collagens I and III. These effects of insulin may in part be mediated through cytoskeletal rearrangement. Differences in cytoskeletal arrangement were compared between SI-MCs and SI+MCs and 1 hr after addition of insulin (1 nM) or IGF-1 (100 nM) to SI-MCs. Cells were examined by light microscopy, electron microscopy, and immunostaining for specific cytoskeletal proteins and fibronectin. Insulin induced rapid rearrangement of stress fibers. Surface ruffling, actin aggregation, vimentin retraction, rearrangement of vinculin in focal adhesions, and fibronectin extraction were apparent. These direct effects of insulin on the SI-MC cytoskeleton occurred before insulin-induced changes in ECM composition. IGF-I induced cytoskeletal reorganization distinct from insulin. These observations demonstrate that insulin and IGF-I have unique effects on the MC cytoskeleton, which is turn may mediate secondary ligand effects on MCs.

P-450 Metabolites of Arachidonic Acid in the Control of Cardiovascular Function

2002 ◽  
Vol 82 (1) ◽  
pp. 131-185 ◽  
Author(s):  
Richard J. Roman
Keyword(s):  
Arachidonic Acid ◽  
Angiotensin Ii ◽  
Vascular Tone ◽  
Mesangial Cells ◽  
Cardiovascular Function ◽  
Tubuloglomerular Feedback ◽  
Peripheral Vasculature ◽  
Therapeutic Benefits

Recent studies have indicated that arachidonic acid is primarily metabolized by cytochrome P-450 (CYP) enzymes in the brain, lung, kidney, and peripheral vasculature to 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) and that these compounds play critical roles in the regulation of renal, pulmonary, and cardiac function and vascular tone. EETs are endothelium-derived vasodilators that hyperpolarize vascular smooth muscle (VSM) cells by activating K+channels. 20-HETE is a vasoconstrictor produced in VSM cells that reduces the open-state probability of Ca2+-activated K+channels. Inhibitors of the formation of 20-HETE block the myogenic response of renal, cerebral, and skeletal muscle arterioles in vitro and autoregulation of renal and cerebral blood flow in vivo. They also block tubuloglomerular feedback responses in vivo and the vasoconstrictor response to elevations in tissue Po2both in vivo and in vitro. The formation of 20-HETE in VSM is stimulated by angiotensin II and endothelin and is inhibited by nitric oxide (NO) and carbon monoxide (CO). Blockade of the formation of 20-HETE attenuates the vascular responses to angiotensin II, endothelin, norepinephrine, NO, and CO. In the kidney, EETs and 20-HETE are produced in the proximal tubule and the thick ascending loop of Henle. They regulate Na+transport in these nephron segments. 20-HETE also contributes to the mitogenic effects of a variety of growth factors in VSM, renal epithelial, and mesangial cells. The production of EETs and 20-HETE is altered in experimental and genetic models of hypertension, diabetes, uremia, toxemia of pregnancy, and hepatorenal syndrome. Given the importance of this pathway in the control of cardiovascular function, it is likely that CYP metabolites of arachidonic acid contribute to the changes in renal function and vascular tone associated with some of these conditions and that drugs that modify the formation and/or actions of EETs and 20-HETE may have therapeutic benefits.

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