Endogenous EGF as a potential renotrophic factor in ischemia-induced acute renal failure

1993 ◽  
Vol 265 (3) ◽  
pp. F425-F434 ◽  
Author(s):  
R. P. Schaudies ◽  
D. Nonclercq ◽  
L. Nelson ◽  
G. Toubeau ◽  
J. Zanen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Time Course ◽  
Tissue Injury ◽  
Cell Turnover ◽  
Paraffin Sections ◽  
Outer Medulla ◽  
New Synthesis ◽  
Predominant Form ◽  
Outer Stripe ◽  
Epidermal Growth

The time course for the increases in soluble renal epidermal growth factor (EGF) after ischemia has been established. These elevated levels of EGF have been compared with the degree of tissue injury as well as the extent of cell proliferation in the recovering tissue. Levels of soluble immunoreactive EGF (irEGF) in control animals were 9.74 +/- 1.1 ng/g wet wt (n = 4-8 for all values) and rose to 83.9 +/- 30 ng/g within 12 h after injury. Soluble irEGF content peaked at 88.8 +/- 15 ng/g at 24 h postinjury and returned to control values by 72 h. We previously reported that trypsin digestion of crude renal membranes (CRM) generates rat EGF that is indistinguishable from that isolated from the submandibular gland. Initial levels of trypsin-releasable membrane-associated irEGF were 439 +/- 26 ng/g. These levels fell to 46.6 +/- 9.6 ng/g at 48 h after injury. The total renal EGF demonstrated an 80% decline 48 h after injury but returned to 50% of the initial values after 72 h representing significant new synthesis of EGF-containing proteins between 48 and 72 h postinjury. Immunohistochemical staining of kidney paraffin sections for EGF immunoreactivity demonstrated staining intensities that paralleled the amount of irEGF in the trypsin-digested CRM fraction, suggesting that the membrane-associated irEGF is the predominant form detected by this technique. Regenerative hyperplasia subsequent to tubular insult was monitored by immunostaining nuclei of S phase cells after pulse labeling with the thymidine analogue 5-bromo-2'-deoxyuridine. Cell proliferation was particularly prominent in the outer stripe of outer medulla of kidneys exposed to ischemia and reached a maximum (19-fold higher than the baseline value) 48 h after reperfusion. Renal cell turnover returned to control values by day 7. The observation that the peak in soluble EGF levels (24 h) precedes the peak in tubular regeneration (48 h) by 24 h is consistent with the hypothesis that EGF is one of the mitogenic signals triggering regenerative hyperplasia after renal injury.

Temporal induction of clusterin in cisplatin nephrotoxicity.

1997 ◽  
Vol 8 (2) ◽  
pp. 302-305
Author(s):  
J R Silkensen ◽  
A Agarwal ◽  
K A Nath ◽  
J C Manivel ◽  
M E Rosenberg
Keyword(s):  
Serum Creatinine ◽  
Time Course ◽  
Tissue Injury ◽  
Kidney Tissue ◽  
Sprague Dawley ◽  
Outer Medulla ◽  
Creatinine Concentration ◽  
Cisplatin Nephrotoxicity ◽  
Tubular Necrosis ◽  
Outer Stripe

Clusterin is a ubiquitous glycoprotein induced in many organs, including the kidney, at times of tissue injury and/or remodeling. It is speculated in this study that clusterin preserves cell interactions that are otherwise perturbed by renal insults. The purpose of this study was to examine clusterin expression after cisplatin nephrotoxicity, a model characterized by a delayed time course of injury and a well-defined site of that injury (proximal tubule). Sprague-Dawley rats were treated with intravenous cisplatin (6 mg/kg) or vehicle. Serum creatinine concentrations were measured and kidneys harvested at 1, 2, and 5 days. Marked induction of clusterin mRNA was seen only at 5 days, a time when serum creatinine concentration was the highest. Histology of kidney tissue 5 days after cisplatin administration revealed marked tubular necrosis localized to the outer stripe of the outer medulla, a region rich in proximal tubules. Immunohistochemistry and in situ hybridization at 5 days demonstrated clusterin primarily in the inner stripe of the outer medulla. In conclusion, expression of clusterin follows renal injury with cisplatin at a time corresponding to the morphologic evidence of tubular necrosis and cell detachment; quite surprisingly, such expression occurs at a site distant from the primary injury.

Cell proliferation is insufficient, but loss of tuberin is necessary, for chemically induced nephrocarcinogenicity

2002 ◽  
Vol 283 (2) ◽  
pp. F262-F270 ◽  
Author(s):  
Hae-Seong Yoon ◽  
Terrence J. Monks ◽  
Jeffrey I. Everitt ◽  
Cheryl L. Walker ◽  
Serrine S. Lau
Keyword(s):  
Cell Proliferation ◽  
Tissue Injury ◽  
Tumor Development ◽  
Suppressor Gene ◽  
Tumor Formation ◽  
Renal Tumors ◽  
Outer Stripe ◽  
Acute Tissue Injury ◽  
Cell Cycle Deregulation ◽  
Erk Activity

Although 2,3,5-tris-(glutathion- S-yl)hydroquinone (TGHQ; 2.5 μmol/kg ip) markedly increased cell proliferation within the outer stripe of the outer medulla (OSOM) of the kidney in both wild-type ( Tsc2+/+ ) and mutant Eker rats ( Tsc2 EK/+), only TGHQ-treated Tsc2 EK/+ rats developed renal tumors, indicating that cell proliferation per se was not sufficient for tumor development. Tuberin expression was initially induced within the OSOM after TGHQ treatment but was lost within TGHQ-induced renal tumors. High extracellular signal-regulated kinase (ERK) activity occurred in the OSOM of Tsc2 EK/+ rats at 4 mo and in TGHQ-induced renal tumors. Cyclin D1 was also highly expressed in TGHQ-induced renal tumors. Reexpression of Tsc2 in tuberin-negative cells decreased ERK activity, consistent with the growth-suppressive effects of this tumor suppressor gene. Thus 1) stimulation of cell proliferation after toxicant insult is insufficient for tumor formation; 2) tuberin induction after acute tissue injury suggests that Tsc2 is an acute-phase response gene, limiting the proliferative response after injury; and 3) loss of Tsc2 gene function is associated with cell cycle deregulation.

Time course of renal glutamate dehydrogenase induction during NH4Cl loading in rats

1992 ◽  
Vol 262 (6) ◽  
pp. F999-F1006 ◽  
Author(s):  
P. A. Wright ◽  
R. K. Packer ◽  
A. Garcia-Perez ◽  
M. A. Knepper
Keyword(s):  
Glutamate Dehydrogenase ◽  
Time Course ◽  
Renal Cortex ◽  
Ammonium Excretion ◽  
Mrna Levels ◽  
Outer Medulla ◽  
Acid Intake ◽  
Blood Ph ◽  
Outer Stripe ◽  
Acid Loading

To study mechanisms involved in renal glutamate dehydrogenase (GDH) regulation in response to systemic acid loading, we have measured blood pH, ammonium excretion, renal GDH mRNA levels, and GDH activity in rats. Acid intake (0.28 M NH4Cl in drinking water for 3 days) increased GDH mRNA levels in the renal cortex, but had no effect in the outer stripe of the outer medulla, inner stripe of the outer medulla, or the inner medulla. Rats were subjected to a step change in acid intake by alkali loading for 3 days (7.2 meq NaHCO3 per day in food slurry) and shifting to acid loading for up to 7 days (7.2 meq NH4Cl in food slurry). Ammonium excretion rose rapidly, increasing by 14-fold in the first 24-h period and 38-fold in the second 24-h period. Cortical GDH mRNA levels were increased relative to alkali-loaded values by 3.7-fold in 24 h, 4.3-fold in 4 days, but only 2.2-fold in 7 days. GDH activity was unchanged after 24 h of acid intake, but was significantly increased after 48 h. We concluded the following: 1) GDH mRNA is present in all regions of the kidney, but levels increase in response to acid loading only in the renal cortex; 2) GDH mRNA levels increase within 1 day after the initiation of acid loading, but the associated increase in functional enzyme activity takes 2 or more days; and 3) the large increases in ammonium excretion that occur in the first day after initiation of acid loading are not dependent on increased GDH activity.

Computational Evaluation and In Vitro Validation of New Epidermal Growth Factor Receptor Inhibitors

2020 ◽  
Vol 20 (18) ◽  
pp. 1628-1639
Author(s):  
Sergi Gómez-Ganau ◽  
Josefa Castillo ◽  
Andrés Cervantes ◽  
Jesus Vicente de Julián-Ortiz ◽  
Rafael Gozalbes
Keyword(s):  
Cell Proliferation ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Affinity ◽  
Cell Lines ◽  
Growth Factor Receptor ◽  
Significant Activity ◽  
Epidermal Growth

Background: The Epidermal Growth Factor Receptor (EGFR) is a transmembrane protein that acts as a receptor of extracellular protein ligands of the epidermal growth factor (EGF/ErbB) family. It has been shown that EGFR is overexpressed by many tumours and correlates with poor prognosis. Therefore, EGFR can be considered as a very interesting therapeutic target for the treatment of a large variety of cancers such as lung, ovarian, endometrial, gastric, bladder and breast cancers, cervical adenocarcinoma, malignant melanoma and glioblastoma. Methods: We have followed a structure-based virtual screening (SBVS) procedure with a library composed of several commercial collections of chemicals (615,462 compounds in total) and the 3D structure of EGFR obtained from the Protein Data Bank (PDB code: 1M17). The docking results from this campaign were then ranked according to the theoretical binding affinity of these molecules to EGFR, and compared with the binding affinity of erlotinib, a well-known EGFR inhibitor. A total of 23 top-rated commercial compounds displaying potential binding affinities similar or even better than erlotinib were selected for experimental evaluation. In vitro assays in different cell lines were performed. A preliminary test was carried out with a simple and standard quick cell proliferation assay kit, and six compounds showed significant activity when compared to positive control. Then, viability and cell proliferation of these compounds were further tested using a protocol based on propidium iodide (PI) and flow cytometry in HCT116, Caco-2 and H358 cell lines. Results: The whole six compounds displayed good effects when compared with erlotinib at 30 μM. When reducing the concentration to 10μM, the activity of the 6 compounds depends on the cell line used: the six compounds showed inhibitory activity with HCT116, two compounds showed inhibition with Caco-2, and three compounds showed inhibitory effects with H358. At 2 μM, one compound showed inhibiting effects close to those from erlotinib. Conclusion: Therefore, these compounds could be considered as potential primary hits, acting as promising starting points to expand the therapeutic options against a wide range of cancers.

Is polyamine synthesis involved in the proliferative response of the intestinal epithelium to urogastrone-epidermal growth factor?

1989 ◽  
Vol 76 (6) ◽  
pp. 595-598 ◽  
Author(s):  
R. A. Goodlad ◽  
H. Gregory ◽  
N. A. Wright
Keyword(s):  
Cell Proliferation ◽  
Small Intestine ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Proliferative Response ◽  
Intestinal Cell ◽  
Intestinal Epithelial ◽  
Polyamine Synthesis ◽  
Proliferative Effect ◽  
Epidermal Growth

1. Intestinal epithelial cell proliferation was measured in rats maintained on total parenteral nutriton (TPN), in TPN rats given 300 μg of recombinant human epidermal growth factor (urogastrone-epidermal growth factor, URO-EGF) day−1 kg−1, and in further groups given URO-EGF and difluoromethylornithine (DFMO), an inhibitor of the enzyme ornithine decarboxylase (ODC). 2. URO-EGF significantly increased intestinal cell proliferation throughout the gastrointestinal tract. The proliferative response of the colon was particularly pronounced. 3. DFMO reduced the proliferative effect of urogastrone in the stomach and small intestine. DFMO also reduced URO-EGF-stimulated intestinal cell proliferation in the colon, but to a lesser extent. 4. It is concluded that ODC is essential for effecting the proliferative response of the stomach and small intestine to URO-EGF, but this role may be less important in the colon.

AQP3, p-AQP2, and AQP2 expression is reduced in polyuric rats with hypercalcemia: prevention by cAMP-PDE inhibitors

2002 ◽  
Vol 283 (6) ◽  
pp. F1313-F1325 ◽  
Author(s):  
Weidong Wang ◽  
Chunling Li ◽  
Tae-Hwan Kwon ◽  
Mark A. Knepper ◽  
Jørgen Frøkiær ◽  
...  
Keyword(s):  
Vitamin D ◽  
Collecting Duct ◽  
Urine Osmolality ◽  
Outer Medulla ◽  
Camp Phosphodiesterase ◽  
Aqp4 Expression ◽  
Pde Inhibitors ◽  
Aqp1 Expression ◽  
Outer Stripe ◽  
Inhibitor Treatment

The purpose of this study was to evaluate whether hypercalcemia is associated with downregulation of renal aquaporins (AQPs), including AQP1, AQP2, phosphorylated AQP2 (p-AQP2), AQP3, and AQP4, and if this is the case, to test whether cAMP-phosphodiesterase (PDE) inhibitor treatment can prevent AQP downregulation and prevent the development of polyuria. Vitamin D-induced hypercalcemia in rats was associated with increased urine output and reduced urine osmolality, consistent with previous findings (Levi M, Peterson L, and Berl T. Kidney Int 23: 489–497, 1983). Semiquantitative immunoblotting revealed a significant reduction in the abundance of inner medullary AQP2 (52 ± 6% of control levels), consistent with previous studies, and of AQP2, which is phosphorylated at the PKA phosphorylation consensus site serine 256 (p-AQP2; 36 ± 8%). Moreover, AQP3 abundance was also significantly decreased (45 ± 7 and 61 ± 6% of control levels in inner medulla and whole kidney, respectively). Consistent with this, immunohistochemistry demonstrated reduced AQP3 immunolabeling along the entire collecting duct. AQP4 expression was not reduced. Surprisingly, total kidney AQP1 abundance was also reduced (60 ± 6%). AQP1 expression was reduced in the cortex and outer stripe of the outer medulla (48 ± 7%; i.e., in proximal tubules). In contrast, AQP1 levels were not changed in the inner stripe of the outer medulla or in the inner medulla (i.e., descending thin limbs and vasa recta). Treatment with the cAMP-PDE inhibitors rolipram and milrinone in combination (inhibiting PDE IV and PDE III isoenzymes) at day 2 and onward completely prevented the hypercalcemia-induced downregulation of AQP2 and AQP3 (but not AQP1) and completely prevented the development of polyuria. In conclusion, AQP3, AQP2, and p-AQP2 are downregulated and are likely to play critical roles in the development of polyuria associated with vitamin D-induced hypercalcemia. Moreover, PDE inhibitor treatment significantly prevented the reduced expression of collecting duct AQPs and prevented the development of polyuria.

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