scholarly journals Cyst fluid from human autosomal dominant polycystic kidneys promotes cyst formation and expansion by renal epithelial cells in vitro.

1992 ◽  
Vol 3 (4) ◽  
pp. 984-994
Author(s):  
M Ye ◽  
M Grant ◽  
M Sharma ◽  
L Elzinga ◽  
S Swan ◽  
...  
Keyword(s):  
Growth Factor ◽  
Autosomal Dominant ◽  
Renal Cysts ◽  
Secretory Activity ◽  
Collagen Matrix ◽  
Fluid Secretion ◽  
Cyst Formation ◽  
Cyst Fluid ◽  
Epidermal Growth

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive renal enlargement, culminating in renal insufficiency in over one half of affected individuals. The highly variable onset and clinical course of ADPKD may be due to factors extrinsic to the genetically defined renal cysts. In this study, cyst fluid samples from 12 nonazotemic and 18 azotemic ADPKD subjects were examined for in vitro biologic activity that promotes cellular proliferation and the secretion of fluid by renal epithelial monolayers, two pathogenetic mechanisms that have critical roles in the formation and the rate of expansion of renal cysts. Cyst fluid added to culture medium (final concentrations, 1 to 20%) caused Madin-Darby canine kidney cells and human kidney cortex (HKC) cells derived from primary cultures to form cysts in Type I collagen matrix. Cyst fluid stimulated the net transepithelial secretion of fluid by polarized monolayers composed of these same cells. Absolute levels of fluid secretory activity determined by MDCK bioassay were correlated directly with the rate of fluid secretion by HKC cell monolayers and with the extent of cyst formation by MDCK and HKC cells embedded in collagen matrix. The secretory activity of urine was negligible; secretory activity was detectable in the serum of normal and ADPKD subjects, but the levels were much lower than in cyst fluid. cAMP agonists prostaglandins E1 and E2, arginine vasopressin, and 8-Br-cAMP stimulated fluid secretion by MDCK and HKC monolayers, but these substances did not cause HKC cells to form cysts in collagen matrix, whereas cyst fluid did. Among other naturally occurring growth factors and autacoids, only epidermal growth factor and transforming growth factor alpha stimulated cyst formation by HKC cells; however, the capacity of cyst fluid to stimulate fluid secretion was not affected by treatment with antiserum to epidermal growth factor. It was concluded that potent, and possibly unique, substances in the cyst fluids of individuals with ADPKD support and augment biologic processes in renal epithelial cells that may be important in the promotion of progressive cyst expansion.

scholarly journals 1992 Homer Smith Award. Fluid secretion, cellular proliferation, and the pathogenesis of renal epithelial cysts.

1993 ◽  
Vol 3 (12) ◽  
pp. 1841-1857 ◽  
Author(s):  
J J Grantham
Keyword(s):  
Growth Factors ◽  
Epithelial Cells ◽  
Cellular Proliferation ◽  
Early Stage ◽  
Renal Cysts ◽  
Fluid Secretion ◽  
Cyst Formation ◽  
Renal Tubules ◽  
Epidermal Growth

Renal cysts, caused by hereditary or acquired disorders, develop in tubule segments. The central pathogenetic elements of cyst formation include abnormal cellular proliferation, accumulation of intratubular liquid, and remodeling of the extracellular matrix. This review addresses the pathogenetic basis of liquid collection and cellular proliferation. Cavity liquid. At an early stage of growth, most renal cysts become detached from the tubule segment of origin; thus, transepithelial fluid secretion is the source of the liquid in most macroscopic cysts. Evidence from in situ and in vitro studies of intact cysts and epithelium cultured from cyst walls and normal renal tubules indicates that: (1) solutes (NaCl) are secreted into the cysts and water flows secondarily by osmosis; (2) active Na+ transport has a primary or secondary role in the secretion of Na+ and Cl-; and (3) the rate of liquid secretion can be modulated by hormones (arginine vasopressin), autocoids (prostaglandin E1 and E2), growth factors (epidermal growth factor), and unknown factors in cyst fluids. Cellular proliferation. Epithelial cells of renal cysts appear to proliferate more than normal. Each cyst resembles a tumor, except that the mass is composed primarily of liquid rather than cells. The proliferation of cyst epithelial cells is associated with: (1) abnormal expression of proto-oncogenes; (2) abnormal displays of morphologic and biochemical phenotypic markers; and (3) abnormal responsiveness to growth factors. The maturation arrest hypothesis, introduced as a framework to explore the pathogenetic basis of all renal cysts, supposes that the epithelial cells comprising cysts are "locked" in an immature, dedifferentiated state. Therapeutic strategies to control the growth of renal cysts may reasonably target processes that inhibit fluid secretion, maximize fluid absorption, and redifferentiate the immature and abnormally proliferative epithelial cells within cysts.

scholarly journals Endogenous concentrations of ouabain act as a cofactor to stimulate fluid secretion and cyst growth of in vitro ADPKD models via cAMP and EGFR-Src-MEK pathways

2012 ◽  
Vol 303 (7) ◽  
pp. F982-F990 ◽  
Author(s):  
Kyle Jansson ◽  
Anh-Nguyet T. Nguyen ◽  
Brenda S. Magenheimer ◽  
Gail A. Reif ◽  
Lavakumar Reddy Aramadhaka ◽  
...  
Keyword(s):  
Fluid Transport ◽  
Egf Receptor ◽  
Synergistic Effects ◽  
Wild Type Mouse ◽  
Renal Cysts ◽  
Human Kidney ◽  
Collagen Matrix ◽  
Fluid Secretion ◽  
Cyst Growth

In autosomal-dominant polycystic kidney disease (ADPKD), renal cysts develop by aberrant epithelial cell proliferation and transepithelial fluid secretion. We previously showed that ouabain increases proliferation of cultured human ADPKD cells via stimulation of the EGF receptor (EGFR)-Src-MEK/ERK signaling pathway. We examined whether ouabain affects fluid secretion and in vitro cyst growth of human ADPKD cell monolayers, ADPKD cell microcysts cultured in a three-dimensional collagen matrix, and metanephric organ cultures from Pkd1 m1Bei mice. Physiological concentrations of ouabain alone did not affect net transepithelial basal-to-apical fluid transport in ADPKD monolayers or growth of cultured ADPKD microcysts. In contrast, in the presence of forskolin or 8-bromo-cAMP, ouabain significantly enhanced ADPKD fluid secretion and microcyst expansion. Ouabain exerted this effect by enhancing cAMP-dependent Cl− secretion via the CFTR. Similarly, ouabain accelerated cAMP-dependent cyst enlargement in Pkd1 m1Bei mice metanephroi, with a more prominent response in homozygous than heterozygous mice. Ouabain had no effect on fluid secretion and cystogenesis of normal human kidney cells and caused only slight cystic dilations in wild-type mouse kidneys. The effects of ouabain in ADPKD cells and Pkd1 m1Bei metanephroi were prevented by inhibitors of EGFR (AG1478), Src (PP2), and MEK (U0126). Together, our results show that ouabain, used in physiological concentrations, has synergistic effects on cAMP-mediated fluid secretion and cyst growth, via activation of the EGFR-Src-MEK pathway. These data provide important evidence for the role of ouabain as an endogenous hormone that exacerbates ADPKD cyst progression.

scholarly journals Evidence for a potent lipid secretagogue in the cyst fluids of patients with autosomal dominant polycystic kidney disease.

1995 ◽  
Vol 6 (4) ◽  
pp. 1242-1249
Author(s):  
J J Grantham ◽  
M Ye ◽  
C Davidow ◽  
B Holub ◽  
M Sharma
Keyword(s):  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Autosomal Dominant ◽  
Secretory Activity ◽  
Fluid Secretion ◽  
Cyst Fluid ◽  
Polycystic Kidney ◽  
Madin Darby Canine Kidney ◽  
Autosomal Dominant Polycystic Kidney ◽  
Darby Canine Kidney

Transepithelial fluid secretion appears to be an important factor in the progressive enlargement of cysts in autosomal dominant polycystic kidney disease. Evidence indicates that the fluid within cysts harbors an autocrine, paracrine, or endocrine secretagogue with the capacity to modulate the rate of cyst expansion. Fluids from five patients with autosomal dominant polycystic kidney disease were studied to determine the chemical nature and the physiologic function of the putative secretagogue. The secretory activity of cyst fluid assayed with polarized monolayers of Madin Darby canine kidney cells could be ascribed to a lipophilic substance of molecular weight < 3,500 d that was not destroyed by freezing, boiling, or proteolytic digestion. This lipid stimulated the production of intracellular cAMP and increased the rate of fluid secretion when added to either surface of cultured renal epithelial cells. Anion exchange chromatography revealed biologic secretory activity to a greater extent in the neutral lipid than in the fatty acid and phospholipid fractions separated from cyst fluid. More extensive chromatographic separation showed preferential appearance of the secretagogue in a fraction of neutral lipids enriched in monoglycerides. Among several candidate lipids, 1-mono-arachidonyl glyceride and arachidonic acid were found to mimic the effect of the cyst fluid to stimulate fluid secretion by Madin Darby canine kidney cells; however, their abundance in cyst fluid was insufficient to account for the degree to which secretion was stimulated by cyst fluid. Moreover, the effect of the arachidonic acid species to stimulate fluid secretion was inhibited by treatment with indomethacin, whereas the effect of the cyst fluid was not. On the basis of this study, it was concluded that human autosomal dominant polycystic kidney disease cyst fluid contains an anonymous lipid with the capacity to stimulate fluid secretion in renal epithelia. This potent endogenous modulator of fluid transport may have an important role in determining the rate at which cysts expand in autosomal dominant polycystic disease.

scholarly journals cAMP Regulates Cell Proliferation and Cyst Formation in Autosomal Polycystic Kidney Disease Cells

2000 ◽  
Vol 11 (7) ◽  
pp. 1179-1187 ◽  
Author(s):  
KAZUSHIGE HANAOKA ◽  
WILLIAM B. GUGGINO
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Kidney Disease ◽  
Epidermal Growth Factor ◽  
Fluid Secretion ◽  
Cyst Formation ◽  
Polycystic Kidney ◽  
Epidermal Growth ◽  
Cyst Growth

Abstract. Both epithelial cell proliferation and fluid accumulation are responsible for cyst growth in autosomal dominant polycystic kidney disease (ADPKD). It was previously reported that the cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in cysts from ADPKD patients and suggested that cAMP-stimulated Cl-and fluid secretion occurs through CFTR. The purpose of this study was to investigate the role of cell proliferation in cyst formation in ADPKD and to explore further the role of fluid secretion in cyst growth. Primary cultures both of ADPKD epithelial cells and a mixed population of normal renal epithelial cells isolated from the cortex (HRCE cells) were used. This study tested whether cAMP was involved both in stimulating cell proliferation and formation of cystsin vitro.3H-Thymidine incorporation assays showed that epidermal growth factor stimulated proliferation both in ADPKD cells and HRCE cells. In addition, cAMP stimulated DNA synthesis and cell proliferation in ADPKD, but not HRCE, cells. The effects of cAMP and epidermal growth factor on cell growth in ADPKD cells were additive. cAMP also stimulated cyst enlargement and fluid secretion in ADPKD cells. By contrast, cyst formation and enlargement from HRCE cells occurred without cAMP. Fluid secretion into the cyst lumen was blocked by diphenylamine carboxylic acid (DPC) and glibenclamide in ADPKD cells but blocked only by DPC in HRCE cells. This study showed that ADPKD cells have unique characteristics ; cAMP stimulates fluid secretion and cell proliferation, indicating cAMP plays a very important role in cyst growth during the course of ADPKD.

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.

4-Hydroxyestradiol improves mouse embryo quality, epidermal growth factor-binding capability in vitro and implantation rates

2020 ◽  
Author(s):  
Nuria Hernández ◽  
Marta López-Morató ◽  
Mario J Perianes ◽  
Soledad Sánchez-Mateos ◽  
Vanessa Casas-Rua ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Embryo Quality ◽  
Culture Media ◽  
Embryo Implantation ◽  
In Vivo Models ◽  
Endometrial Cells ◽  
Epidermal Growth ◽  
Binding Capability

Abstract Embryo implantation in the uterus is a critical step to achieve success following ART. Despite favorable uterine conditions, a great number of good quality embryos fail to implant, often for reasons that are unknown. Hence, improving the implantation potential of embryos is a subject of great interest. 4-Hydroxyestradiol (4-OH-E2), a metabolic product of estradiol produced by endometrial cells, plays a key role in endometrial–embryonic interactions that are necessary for implantation. Nonetheless, the effects of 4-OH-E2 on embryos obtained in vitro have not been yet described. This study was designed to determine whether culture media enriched in 4-OH-E2 could improve the quality and implantation rate of embryos obtained in vitro, using both in vitro and in vivo models. We also analyzed its effects on the epidermal growth factor (EGF)-binding capability of the embryos. Our results showed that the presence of 4-OH-E2 in the culture media of embryos during the morula to blastocyst transition increases embryo quality and attachment to endometrial cells in vitro. 4-OH-E2 can also improve viable pregnancy rates of mouse embryos produced in vitro, reaching success rates that are similar to those from embryos obtained directly from the uterus. 4-OH-E2 improved the embryos’ ability to bind EGF, which could be responsible for the increased embryo implantation potential observed. Therefore, our results strongly suggest that 4-OH-E2 is a strong candidate molecule to supplement human IVF culture media in order to improve embryo implantation. However, further research is required before these findings can be translated with efficacy and safety to fertility clinics.

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