scholarly journals Is 100KF an Isoform of Hemopexin? Immunochemical Characterization of the Vasoactive Plasma Factor 100KF

1999 ◽  
Vol 10 (8) ◽  
pp. 1700-1708
Author(s):  
PO KAM CHEUNG ◽  
BEN STULP ◽  
STEPHAN IMMENSCHUH ◽  
THEO BORGHUIS ◽  
JULIUS F. W. BALLER ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Rat Kidney ◽  
Kidney Tissue ◽  
Positive Staining ◽  
Dot Blot ◽  
Glomerular Permeability ◽  
Rat Serum ◽  
Protein Leakage ◽  
Plasma Factor

Abstract. The human vasoactive plasma factor 100KF has been proposed to play a role in minimal change disease in relapse. Since preliminary data suggested similarity between 100KF and the human plasma glycoprotein hemopexin (Hx), this study was conducted to compare 100KF with purified Hx for sequence homology, immunostaining properties in Western and dot-blot assays, ability to affect glomerular ecto-ATPase and glomerular polyanions in vitro, as well as their glomerular permeability increasing effect following alternate perfusion into the rat kidney ex vivo. 100KF was purified from normal pooled plasma according to standard chromatographic techniques, and from the same batch Hx was prepared using affinity chromatography. A second batch of Hx was prepared directly from human serum according to a standard protocol. (For comparison, additional Hx samples obtained from other centers were also included in the study.) The results show: (1) 100% homology of 100KF with plasma Hx after internal sequence analysis; (2) positive staining of the eluate with both monoclonal and polyclonal anti-Hx IgG as well as anti-100KF IgG in dot-blot assays, and similar bands on Western blotting using the same antibodies; (3) affection of glomerular polyanions and glomerular ecto-ATPase after incubation of kidney tissue with either 100KF or Hx (1.5 respectively 1.0 mg/ml; 1.0 h, 37°C), as detected by computerized histochemical quantification; and (4) significant enhancement of urinary protein leakage after Hx perfusion followed by diluted rat serum into the rat kidney ex vivo (Hx: 210.65 ± 49.79 μg protein leakage per min versus heat-inactivated Hx control: 112.2 ± 49.18 μg per min [both n = 6]). From these data and from the observation that both Hx and 100KF activity can be inhibited by serine protease inhibitors but not by broad spectrum collagenase inhibitors, it is concluded that Hx may be closely related or identical to the active moiety of 100KF.

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

Natriuretic effect of bufalin in isolated rat kidneys involves activation of the Na+-K+-ATPase-Src kinase pathway

2012 ◽  
Vol 302 (8) ◽  
pp. F959-F966 ◽  
Author(s):  
Francisco J. Arnaud-Batista ◽  
Graciana T. Costa ◽  
Ilana Mara Barbosa de Oliveira ◽  
Paula P. C. Costa ◽  
Cláudia F. Santos ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Ex Vivo ◽  
Rat Kidney ◽  
Src Kinase ◽  
Natriuretic Effect ◽  
Intact Kidney ◽  
Kinase Pathway ◽  
Isolated Rat ◽  
Rat Kidneys

Bufadienolides are structurally related to the clinically relevant cardenolides (e.g., digoxin) and are now considered as endogenous steroid hormones. Binding of ouabain to Na+-K+-ATPase has been associated, in kidney cells, to the activation of the Src kinase pathway and Na+-K+-ATPase internalization. Nevertheless, whether the activation of this cascade also occurs with other cardiotonic steroids and leads to diuresis and natriuresis in the isolated intact kidney is still unknown. In the present work, we perfused rat kidneys for 120 min with bufalin (1, 3, or 10 μM) and measured its vascular and tubular effects. Thereafter, we probed the effect of 10 μM 3-(4-chlorophenyl)1-(1,1-dimethylethyl)-1H-pyrazolo[3,4-d]pyrimidin-4amine (PP2), a Src family kinase inhibitor, and 1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio] butadiene (UO126), a highly selective inhibitor of both MEK1 and MEK2, on bufalin-induced renal alterations. Bufalin at 3 and 10 μM profundly increased several parameters of renal function in a time- and/or concentration-dependent fashion. At a concentration that produced similar inhibition of the rat kidney Na+-K+-ATPase, ouabain had a much smaller diuretic and natriuretic effect. Although bufalin fully inhibited the rat kidney Na+-K+-ATPase in vitro, its IC50 (33 ± 1 μM) was threefold higher than the concentration used ex vivo and all its renal effects were blunted by PP2 and UO126. Furthermore, the phosphorylated (activated) ERK1/2 expression was increased after bufalin perfusion and this effect was totally prevented after PP2 pretreatment. The present study shows for the first time the direct diuretic, natriuretic, and kaliuretic effects of bufalin in isolated rat kidney and the relevance of Na+-K+-ATPase-mediated signal transduction.

scholarly journals Niao Du Kang Mixture Increases the Expression of mir-129-5p to Relieve Renal Fibrosis

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yan-lin Li ◽  
Lin-na Liu ◽  
Lin Huang ◽  
Hai-wen An ◽  
Jian-lin Jian ◽  
...  
Keyword(s):  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Cell Model ◽  
Rat Kidney ◽  
Kidney Tissue ◽  
Urine Protein ◽  
Renal Interstitial Fibrosis ◽  
Expression Levels ◽  
Qrt Pcr

Objective. To investigate the efficacy of Niao Du Kang (NDK) mixture in renal fibrosis of rats and to explore the mechanism underlying the effect of NDK on renal fibrosis. Methods. Unilateral ureteral obstruction (UUO) was used to replicate a rat renal interstitial fibrosis model. The drug-administered groups were given 20 ml/kg (NDK-H), 10 ml/kg (NDK-M), and 5 ml/kg (NDK-L) NDK mixture once a day for 21 days beginning 48 hours after surgery. The 24-hour urine protein and serum creatinine (CR) levels in the sham group rats, UUO rats, and NDK mixture-treated rats were measured after the last administration. The pathological changes of rat kidney tissue were observed by HE staining. The degree of fibrosis was observed by Masson’s staining and scored. The expression levels of TGF-β, α-SMA mRNA, and mir-129-5p in kidney were detected by qRT-PCR. HK-2 cells were treated with 5 ng/ml TGF-β to induce HK-2 cell fibrosis. The expression levels of TGF-β, α-SMA mRNA, and mir-129-5p in HK-2 cells were detected by qRT-PCR. TargetScan predicted the target gene of mir-129-5p, HK-2 cells were transfected with mir-129-5p mimic, and an overexpressed mir-129-5p HK-2 cell model was constructed. qRT-PCR was used to detect the expression of PDPK1 mRNA. Western blot was used to detect the expression of PDPK1, AKT, and p-AKT in HK-2 cells induced by TGF-β and in UUO rats. Results. NDK mixture significantly reduced the 24-hour urine protein and CR levels of UUO rats. HE staining showed that the NDK mixture group exhibited a significantly reduced degree of renal interstitial fibrosis. NDK mixture also reduced the expression of TGF-β and α-SMA, and the middle-dose group showed a better therapeutic effect. In vitro studies showed that NDK mixture-containing serum increased the expression of mir-129-5p to reduce renal fibrosis. In addition, NDK mixture increased the expression of mir-129-5p in vivo. Further studies indicated that mir-129-5p could target PDPKl to reduce its expression. The NDK-containing serum group also exhibited reduced expression of PDPK1. Conclusion. NDK mixture can significantly improve renal function and improve renal fibrosis in UUO model rats. Furthermore, NDK mixture can inhibit the expression of PDPK1 by upregulating the expression of mir-129-5p and then inhibiting the PI3K/AKT pathway to improve renal fibrosis.

scholarly journals COLORIMETRIC INVESTIGATION OF THE UPTAKE OF AN INTRAVENOUSLY INJECTED PROTEIN (HORSERADISH PEROXIDASE) BY RAT KIDNEY AND EFFECTS OF COMPETITION BY EGG WHITE

1962 ◽  
Vol 12 (2) ◽  
pp. 231-246 ◽  
Author(s):  
W. Straus
Keyword(s):  
Body Weight ◽  
Horseradish Peroxidase ◽  
Intravenous Injection ◽  
Intraperitoneal Injection ◽  
Rat Kidney ◽  
Kidney Tissue ◽  
Egg White ◽  
Foreign Protein ◽  
Tubule Cells

After intravenous injection of horseradish peroxidase into rats, the foreign protein appeared in the kidney first in the small phagosomes and its concentration there decreased quickly; it then was concentrated and "stored" for several days in the large phagosomes. After injection of 10 mg of peroxidase per 100 gm of body weight, the concentration of peroxidase in blood and urine decreased exponentially during the first 6 hours; small amounts of peroxidase were excreted in the urine for several days. When 0.05 to 1.0 mg of peroxidase per 100 gm were administered, most of the peroxidase was taken up by the liver and little by the kidney, and a portion was excreted in the urine even at the lowest dose. At doses above 1.5 mg per 100 gm, the liver cells were saturated, and large reabsorption droplets appeared in the tubule cells of the kidney. With further dosage increase, the concentration of peroxidase in the phagosomes of the kidney increased rapidly until saturation was reached at doses of 13 mg per 100 gm. After intraperitoneal injection of egg white 18 hours prior to the administration of peroxidase, the concentration of peroxidase in all kidney fractions was only 10 to 25 per cent of the values for the untreated animals, the disappearance of peroxidase from the blood was delayed, and 81 percent more peroxidase was excreted in the urine. The treatment with egg white had no effect on the uptake of peroxidase by the liver. The ability of kidney tissue to degrade and adsorb peroxidase in vitro was tested.

Tubular handling of neurotensin in the rat kidney as studied by micropuncture and HPLC

1989 ◽  
Vol 256 (1) ◽  
pp. F100-F106
Author(s):  
T. Bjerke ◽  
E. I. Christensen ◽  
N. Boye
Keyword(s):  
High Performance ◽  
Rat Kidney ◽  
Proximal Tubules ◽  
Urinary Recovery ◽  
Rat Serum ◽  
Proximal Tubular ◽  
Distal Tubules ◽  
Extensive Degradation ◽  
Convoluted Tubules

Micropuncture studies were performed to assess the reabsorption and metabolism of the vasoactive peptide neurotensin (NT) in individual nephron segments and compare it to the handling of the closely related peptide bradykinin (BK). Rat proximal and distal convoluted tubules were microinfused with [3H]NT or [3H]BK. In a second set of experiments, [3H]NT and its metabolites in the ureteral urine were separated and characterized using high-performance liquid chromatography (HPLC) technique. The urinary recovery of 3H-labeled material was 31% when proximal tubules were microinfused with [3H]NT and 94% when distal tubules were infused. For proximal tubules the label recovered in the ureteral urine consisted exclusively of metabolites of NT and appeared as tyrosine, NT1-11, probably NT9-13, and two uncharacterized products. For distal tubules, 9% chromatographed as intact NT in the urine and except for the proportion the metabolites were almost identical to those found when proximal tubules were microinfused. Following microinfusion of [3H]BK into proximal tubules, the urinary recovery of 3H-labeled material was 19%. There was no correlation between fractional reabsorption of 3H-labeled material and proximal tubular length when [3H]NT or [3H]BK was microinfused. In vitro incubation studies with rat ureteral urine showed extensive degradation of NT yielding tyrosine, NT1-6, probably NT9-13, NT, and two uncharacterized products. In contrast, there was no detectable breakdown of BK over a 32-min period. Finally, [3H]NT was incubated in rat serum, and these experiments also showed degradation of the peptide but not to the extent as when incubated in ureteral urine.(ABSTRACT TRUNCATED AT 250 WORDS)

Thromboxane synthetase inhibition improves function of hydronephrotic rat kidneys

1986 ◽  
Vol 250 (2) ◽  
pp. F282-F287 ◽  
Author(s):  
P. E. Klotman ◽  
S. R. Smith ◽  
B. D. Volpp ◽  
T. M. Coffman ◽  
W. E. Yarger
Keyword(s):  
Prostaglandin E2 ◽  
Ex Vivo ◽  
Rat Kidney ◽  
Parent Compound ◽  
Rabbit Kidney ◽  
Excretory Function ◽  
Thromboxane Synthetase ◽  
Rat Kidneys

Twenty-four hours of complete unilateral ureteral obstruction (UUO) produces intense renal vasconstriction in the rat even after release of obstruction. In the ex vivo perfused hydronephrotic rabbit kidney, bradykinin stimulates increased production of the vasoconstrictor autocoid thromboxane. In the present study, we measured basal and bradykinin-stimulated thromboxane and prostaglandin E2 production by UUO and contralateral rat kidneys perfused ex vivo. Furthermore, we evaluated thromboxane synthetase inhibition by imidazole and by two of its substituted derivatives, UK 37248 and UK 38485, in vitro. We compared these in vitro findings with in vivo measurements of renal hemodynamics and excretory function before and after the intrarenal artery administration of thromboxane synthetase inhibitors. Both basal and bradykinin-stimulated thromboxane and prostaglandin E2 production were significantly increased in hydronephrotic kidneys. Imidazole and its substituted congeners were effective inhibitors of bradykinin-stimulated thromboxane B2 production in vitro. However, the substituted imidazoles were more potent, more efficacious, and more selective for thromboxane synthetase inhibition than the parent compound. In vivo, administration of imidazole into the renal artery of the UUO kidney improved function slightly, whereas administration of UK 37248 or UK 38485 doubled renal blood flow and excretory function but did not restore them to normal. We conclude that the hydronephrotic rat kidney produces increased amounts of the vasoconstrictor eicosanoid thromboxane and that thromboxane is an important mediator of vasoconstriction in this model of disease.

scholarly journals Comparative in vitro and ex vivo activities of selected inhibitors of transthyretin aggregation: relevance in drug design

2007 ◽  
Vol 408 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Isabel Cardoso ◽  
Maria Rosário Almeida ◽  
Nelson Ferreira ◽  
Gemma Arsequell ◽  
Gregorio Valencia ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Large Scale ◽  
Serum Proteins ◽  
Ex Vivo ◽  
In Vitro Assays ◽  
Screening Methods ◽  
Wild Type ◽  
Dot Blot ◽  
Amino Benzoic Acid

Destabilization of the tetrameric fold of TTR (transthyretin) is important for aggregation of the protein which culminates in amyloid fibril formation. Many TTR mutations interfere with tetramer stability, increasing the amyloidogenic potential of the protein. The vast majority of proposed TTR fibrillogenesis inhibitors are based on in vitro assays with isolated protein, limiting their future use in clinical assays. In the present study we investigated TTR fibrillogenesis inhibitors using a cellular system that produces TTR intermediates/aggregates in the medium. Plasmids carrying wild-type TTR, V30M or L55P cDNA were transfected into a rat Schwannoma cell line and TTR aggregates were investigated in the medium using a dot-blot filter assay followed by immunodetection. Results showed that, in 24 h, TTR L55P forms aggregates in the medium, whereas, up to 72 h, wild-type TTR and V30M do not. A series of 12 different compounds, described in the literature as in vitro TTR fibrillogenesis inhibitors, were tested for their ability to inhibit L55P aggregate formation; in this system, 2-[(3,5-dichlorophenyl) amino] benzoic acid, benzoxazole, 4-(3,5-difluorophenyl) benzoic acid and tri-iodophenol were the most effective inhibitors, as compared with the reference iododiflunisal, previously shown by ex vivo and in vitro procedures to stabilize TTR and inhibit fibrillogenesis. Among these drugs, 2-[(3,5-dichlorophenyl) amino] benzoic acid and tri-iodophenol stabilized TTR from heterozygotic carriers of V30M in the same ex vivo conditions as those used previously for iododiflunisal. The novel cellular-based test herein proposed for TTR fibrillogenesis inhibitor screens avoids not only lengthy and cumbersome large-scale protein isolation steps but also artefacts associated with most current in vitro first-line screening methods, such as those associated with acidic conditions and the absence of serum proteins.

scholarly journals Ex Vivo and In Vivo Properties of an Injectable Hydrogel Derived From Acellular Ear Cartilage Extracellular Matrix

2021 ◽  
Vol 9 ◽  
Author(s):  
Danni Gong ◽  
Fei Yu ◽  
Meng Zhou ◽  
Wei Dong ◽  
Dan Yan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Histological Analysis ◽  
Ex Vivo ◽  
Positive Staining ◽  
Gelation Kinetics ◽  
Ear Cartilage ◽  
Kinetics Of

Extracellular matrix (ECM) hydrogels provide advantages such as injectability, the ability to fill an irregularly shaped space, and the adequate bioactivity of native matrix. In this study, we developed decellularized cartilage ECM (dcECM) hydrogels from porcine ears innovatively via the main method of enzymatic digestion and verified good biocompatible properties of dcECM hydrogels to deliver chondrocytes and form subcutaneous cartilage in vivo. The scanning electron microscopy and turbidimetric gelation kinetics were used to characterize the material properties and gelation kinetics of the dcECM hydrogels. Then we evaluated the biocompatibility of hydrogels via the culture of chondrocytes in vitro. To further explore the dcECM hydrogels in vivo, grafts made from the mixture of dcECM hydrogels and chondrocytes were injected subcutaneously in nude mice for the gross and histological analysis. The structural and gelation kinetics of the dcECM hydrogels altered according to the variation in the ECM concentrations. The 10 mg/ml dcECM hydrogels could support the adhesion and proliferation of chondrocytes in vitro. In vivo, at 4 weeks after transplantation, cartilage-like tissues were detected in all groups with positive staining of toluidine blue, Safranin O, and collagen II, indicating the good gelation of dcECM hydrogels. While with the increasing concentration, the tissue engineering cartilages formed by 10 mg/ml dcECM hydrogel grafts were superior in weights, volumes, collagen, and glycosaminoglycan (GAG) content compared to the dcECM hydrogels of 1 mg/ml and 5 mg/ml. At 8 weeks after grafting, dcECM hydrogel grafts at 10 mg/ml showed very similar qualities to the control, collagen I grafts. After 12 weeks of in vivo culture, the histological analysis indicated that 10 mg/ml dcECM hydrogel grafts were similar to the normal cartilage from pig ears, which was the source tissue. In conclusion, dcECM hydrogel showed the promising potential as a tissue engineering biomaterial to improve the regeneration and heal injuries of ear cartilage.

Developmental approaches to kidney tissue engineering

2004 ◽  
Vol 286 (1) ◽  
pp. F1-F7 ◽  
Author(s):  
Dylan L. Steer ◽  
Sanjay K. Nigam
Keyword(s):  
Tissue Engineering ◽  
Ex Vivo ◽  
Kidney Tissue ◽  
Branching Morphogenesis ◽  
Model Systems ◽  
Renal Stem Cells ◽  
Mesenchymal Differentiation ◽  
Successful Transplantation ◽  
Vitro Model

Recent advances in our understanding of the developmental biology of the kidney, as well as the establishment of novel in vitro model systems, have potential implications for kidney tissue engineering. These advances include delineation of the roles of a number of growth factors in the developmental programs of branching morphogenesis and mesenchymal differentiation, a new understanding of the roles of the extracellular matrix, identification of potential “renal” stem cells, the ex vivo propagation and subsequent recombination of isolated components of the kidney, and successful transplantation of renal primordia into adult hosts. This review will examine these advances in the context of approaches to tissue engineering. Finally, novel approaches that synthesize advances in both cell-based and organ-based approaches are proposed.

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