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Rheal A Towner - One of the best experts on this subject based on the ideXlab platform.
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supergag biopolymers for treatment of excessive Bladder Permeability
Pharmacology Research & Perspectives, 2021Co-Authors: Rheal A Towner, Nataliya Smith, Debra Saunders, Ehsan Mohammadi, Beverley Greenwoodvan Meerveld, Grannum R Sant, Harrison C Shain, Thomas H Jozefiak, Robert E HurstAbstract:Few therapeutic options exist for treatment of IC/BPS. A novel high MW GAG biopolymer ("SuperGAG") was synthesized by controlled oligomerization of CS, purified by TFF and characterized by SEC-MALLS and 1H-NMR spectroscopy. The modified GAG biopolymer was tested in an OVX female rat model in which Bladder Permeability was induced by a 10-minute intravesicular treatment with dilute (1 mg/ml) protamine sulfate and measured by classical Ussing Chamber TEER measurements following treatment with SuperGAG, chondroitin sulfate, or saline. The effect on abrogating the abdominal pain response was assessed using von Frey filaments. The SuperGAG biopolymer was then investigated in a second, genetically modified mouse model (URO-MCP1) that increasingly is accepted as a model for IC/BPS. Permeability was induced with a brief exposure to a sub-noxious dose of LPS and was quantified using contrast-enhanced MRI (CE-MRI). The SuperGAG biopolymer restored imPermeability to normal levels in the OVX rat model as measured by TEER in the Ussing chamber and reduced the abdominal pain response arising from induced Permeability. Evaluation in the URO-MCP1 mouse model also showed restoration of Bladder imPermeability and showed the utility of CE-MRI imaging for evaluating the efficacy of agents to restore Bladder imPermeability. We conclude novel high MW SuperGAG biopolymers are effective in restoring urothelial imPermeability and reducing pain produced by loss of the GAG layer on the urothelium. SuperGAG biopolymers could offer a novel and effective new therapy for IC/BPS, particularly if combined with MRI to assess the efficacy of the therapy.
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assessing Bladder hyper Permeability biomarkers in vivo using molecularly targeted mri
American journal of nuclear medicine and molecular imaging, 2020Co-Authors: Rheal A Towner, Nataliya Smith, Debra Saunders, Beverley Greenwoodvan Meerveld, Megan R Lerner, Robert E HurstAbstract:The objective was to investigate if some of the key molecular players associated with Bladder hyper-Permeability in interstitial cystitis/Bladder pain syndrome (IC/BPS) could be visualized with molecularly-targeted magnetic resonance imaging (mt-MRI) in vivo. IC/BPS is a chronic, painful condition of the Bladder that affects primarily women. It has been demonstrated over the past several decades that Permeability plays a substantial role in IC/BPS. There are several key molecular markers that have been associated with Permeability, including glycolsaminoglycan (GAG), biglycan, chondroitin sulfate, decorin, E-cadherin, keratin 20, uroplakin, vascular endothelial growth factor receptor 1 (VEGF-R1), claudin-2 and zonula occludens-1 (ZO-1). We used in vivo molecularly-targeted MRI (mt-MRI) to assess specific urothelial biomarkers (decorin, VEGF-R1, and claudin-2) associated with Bladder hyper-Permeability in a protamine sulfate (PS)-induced rat model. The mt-MRI probes consisted of an antibody against either VEGF-R1, decorin or claudin-2 conjugated to albumin that had also Gd-DTPA (gadolinium diethylene triamine penta acetic acid) and biotin attached. mt-MRI- and histologically-detectable levels of decorin and VEGF-R1 were both found to decrease following PS-induced Bladder urothelial hyper-Permeability, whereas claudin-2, was found to increase in the rat PS model. Verification of the presence of the mt-MRI probes were done by targeting the biotin moiety for each respective probe with streptavidin-hose radish peroxidase (HRP). Levels of protein expression for VEGF-R1, decorin and claudin-2 were confirmed with immunohistochemistry. In vivo molecularly-targeted MRI (mt-MRI) was found to successfully detect alterations in the expression of decorin, VEGFR1 and claudin-2 in a PS-induced rat Bladder Permeability model. This in vivo molecularly-targeted imaging approach has the potential to provide invaluable information to enhance our understanding of Bladder urothelium hyper-Permeability in IC/BPS patients, and perhaps be used to assist in developing novel therapeutic strategies.
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in vivo detection of Bladder Permeability biomarkers in rodent models using molecular targeted mri
Free Radical Biology and Medicine, 2018Co-Authors: Rheal A Towner, Nataliya Smith, Debra SaundersAbstract:Bladder Permeability is associated with interstitial cystitis (IC). We previously used contrast-enhanced MRI to assess Bladder Permeability in a protamine sulfate (PS)-Bladder Permeability induced rat model, as well as in human patients for IC. This study focuses on the use of molecular-targeted MRI (mtMRI) to assess Bladder Permeability biomarkers in vivo in rodent Bladder Permeability models. Decorin, VEGFR1 (vascular endothelial growth factor receptor 1), and claudin-2 are all known Bladder urothelium markers. Rats (treated with PS)/mice (URO-MCP-1 transgenic treated with lipopolysaccharide (LPS)) were anesthetized with isoflurane for either intravesical PS/LPS or saline administration, and for MRI scans. Targeted contrast agent probes for claudin-2, VEGFR1 or decorin were used to obtain Bladder Permeability biomarker specific images. Multiple Bladder region MR image slices were taken. Pixel-by-pixel relaxation maps were reconstructed from a series of T1-weighted images using a nonlinear two-parameter fitting procedure. The T1 value of a specified region-of-interest (ROI) was computed from all the pixels in the identified ROIs. mtMRI was able to demonstrate altered levels of claudin-2 (Rat PS and URO-MCP-1 mouse LPS models), VEGFR1 and decorin in PS-induced permeable rat Bladders, compared to saline-treated controls. Data indicates the feasibility of conducting in vivo mtMR imaging for the Bladder Permeability biomarker claudin-2 in PS-exposed rat Bladders. Claudin-2 levels are significantly increased (p
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su g iep1 10 Permeability evaluation of interstitial cystitis by dce mri of the Bladder
Medical Physics, 2016Co-Authors: Justin C North, Rheal A Towner, Robert E HurstAbstract:Purpose: Interstitial cystitis (IC) is a chronic and painful condition that can lead to Bladder pain syndrome (BPS) in women. IC and BPS have been known to manifest after physiological changes after giving birth. In this project, we pioneered and advanced a new clinical utility using DCE-MRI to assess Bladder Permeability. At first IC/BPS perfusion methods were with ratio signal evaluation, we now incorporate pharmacokinetics techniques to allow for further assessment. Methods: In this pilot study, female patients and volunteers (IC=4, Control=3) underwent imaging with a clinical GE 3T 750W MRI system. This project was approved by the OUHSC IRB. Multiple TR Images series were acquired. Images were analyzed in the coronal plane at 0-, 3-, 6-, 9-, 12-, 15-, 20-, 25-, and 30-minute intervals. We used a three-compartmental pharmacokinetic model with these data. The compartments included: a) Bladder interior site of injection, b) Bladder wall, and c) external psoas muscle. The signal was transformed and corrected for T1-relaxation based on a multi-TR exponential regression before pharmacokinetic analysis. Results: Significant differences (p<0.05) were detected with relative means for T1 concentration changes (IC/BPS=0.0107, control=0.616) on the outflow between the k13 transfer coefficient, which represents the injection leakage to the external parenchyma. Trend differences (p<0.1) were found in Permeability between the Bladder injection site to the rim. We also found changes in the kurtosis of the histograms of regional perfusion. No detectable changes were found in the reverse directions for the above compartments (k21, k31). Conclusion: We report clinical changes in this pilot study. This study illustrates early detectable evidence for a possible DCE-MRI tool that can detect Permeability differences with pharmacokinetics measurement of k13. These techniques are intended to advance quantitative imaging methods for IC/BPS, per the goals/objectives of the Quantitative Imaging Biomarker Alliance (QIBA) and other AAPM and RSNA initiatives.
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in the absence of overt urothelial damage chondroitinase abc digestion of the gag layer increases Bladder Permeability in ovariectomized female rats
American Journal of Physiology-renal Physiology, 2016Co-Authors: Robert E Hurst, Rheal A Towner, Samuel Van Gordon, Bradley P Kropp, Hsueh Kung Lin, Karl Tyler, John O Marentette, Jane Mchowat, Ehsan Mohammedi, Beverley Greenwoodvan MeerveldAbstract:Loss of integrity of the protective imPermeability barrier in the urothelium has been identified as significant in Bladder dysfunction. In this study, we tested the theory that the luminal layer of...
Mark L Zeidel - One of the best experts on this subject based on the ideXlab platform.
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Bladder Permeability barrier recovery from selective injury of surface epithelial cells
American Journal of Physiology-renal Physiology, 2002Co-Authors: John P Lavelle, Gerard Apodaca, Susan Meyers, Richard Ramage, Sheldon Bastacky, Debra A Doty, Mark L ZeidelAbstract:The mammalian Bladder maintains high electrochemical gradients between urine and blood, permitting the kidney to modify body chemistries through urinary excretion. To perform this function, the urothelium maintains a tight Permeability barrier. When this barrier is damaged, leakage of urine components into the underlying Bladder layers results, with symptoms of cystitis. In these studies, we develop a model of selective urothelial injury using protamine sulfate (PS) and define the process by which this epithelium recovers from damage. Exposure to PS (10 mg/ml), but not vehicle, caused a rapid fall in transepithelial resistance as well as striking increases in water and urea permeabilities. These changes were accompanied by necrosis and sloughing of sheets of umbrella cells, as seen by scanning and transmission electron microscopy. Over the 72 h after PS exposure, barrier function recovered, with transepithelial resistance and water and urea permeabilities returning to normal values. After loss of umbrella cells, the underlying intermediate cells underwent rapid maturation, as evidenced by increased expression of uroplakins and gradual formation of well-defined tight junctions. At day 5 after PS exposure, barrier function was restored and the surface cells exhibited normal-appearing tight junctions and normal labeling for uroplakins and zonula occludens 1. However, the cells remained smaller than umbrella cells until day 10 after exposure, when normal size was restored. These studies develop for the first time a controlled model of selective urothelial damage and demonstrate a characteristic process by which barrier function is restored and underlying intermediate cells develop into mature umbrella cells. This model will be useful in defining the mechanisms that regulate repair of urothelial damage.
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disruption of guinea pig urinary Bladder Permeability barrier in noninfectious cystitis
American Journal of Physiology-renal Physiology, 1998Co-Authors: John P Lavelle, Gerard Apodaca, Susan Meyers, Wily G Ruiz, Mark L ZeidelAbstract:Although most cell membranes permit rapid flux of water, small nonelectrolytes, and ammonia, the apical membranes of Bladder epithelial umbrella cells, which form the Bladder Permeability barrier, exhibit strikingly low permeabilities to these substances. In cystitis, disruption of the Bladder Permeability barrier may irritate the Bladder wall layers underlying the epithelium, causing or exacerbating inflammation, and increasing urinary frequency, urgency, and Bladder pain. To determine the effects of inflammation on the integrity of the Permeability barrier, guinea pigs were sensitized with ovalbumin, and the Bladders were exposed subsequently to antigen by instillation on the urinary side. Inflammation of the Bladder wall markedly reduced transepithelial resistance of dissected epithelium mounted in Ussing chambers and increased water and urea permeabilities modestly at 2 h and more strikingly at 24 h after induction of the inflammation. Transmission and scanning electron microscopy of Bladders at 30 min and 24 h after antigen exposure revealed disruption of tight junctions, denuding of patches of epithelium, and occasional loss of apical membrane architecture. These Permeability and structural effects did not occur in nonsensitized animals in which the Bladders were exposed to antigen and in sensitized animals exposed to saline vehicle rather than antigen. These results demonstrate that inflammation of the underlying muscle and lamina propria can disrupt the Bladder Permeability barrier by damaging tight junctions and apical membranes and causing sloughing of epithelial cells. Leakage of urinary constituents through the damaged epithelium may then exacerbate the inflammation in the underlying muscle layers.
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Permeability properties of the intact mammalian Bladder epithelium
American Journal of Physiology-renal Physiology, 1996Co-Authors: Hilmer Negrete, John P Lavelle, J. Berg, S.a. Lewis, Mark L ZeidelAbstract:Because the mammalian Bladder must store urine of composition which differs markedly from that of plasma for prolonged periods, the Bladder Permeability barrier must maintain extremely low permeabilities to substances which normally cross membranes relatively rapidly, such as water, protons, and small nonelectrolytes like urea and ammonia. In the present studies, permeabilities of the apical membrane of dissected rabbit Bladder epithelium to water, urea, ammonia, and protons were measured in Ussing chambers and averaged (in cm/s) for water, 5.15 +/- 0.43 x 10(-5); for urea, 4.51 +/- 0.67 x 10(-6); for ammonia, 5.14 +/- 0.62 x 10(-4); and for protons, 2.98 +/- 1.87 x 10(-3), respectively. These Permeability values are exceptionally low and are expected to result in minimal to no leakage of these normally permeable substances across the epithelium. Water permeabilities in intact whole rabbit Bladders were indistinguishable from those obtained in the dissected epithelial preparation. Moreover, addition of ny...
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Permeability properties of the intact mammalian Bladder epithelium.
The American journal of physiology, 1996Co-Authors: Hilmer Negrete, John P Lavelle, J. Berg, S.a. Lewis, Mark L ZeidelAbstract:Because the mammalian Bladder must store urine of composition which differs markedly from that of plasma for prolonged periods, the Bladder Permeability barrier must maintain extremely low permeabilities to substances which normally cross membranes relatively rapidly, such as water, protons, and small nonelectrolytes like urea and ammonia. In the present studies, permeabilities of the apical membrane of dissected rabbit Bladder epithelium to water, urea, ammonia, and protons were measured in Ussing chambers and averaged (in cm/s) for water, 5.15 +/- 0.43 x 10(-5); for urea, 4.51 +/- 0.67 x 10(-6); for ammonia, 5.14 +/- 0.62 x 10(-4); and for protons, 2.98 +/- 1.87 x 10(-3), respectively. These Permeability values are exceptionally low and are expected to result in minimal to no leakage of these normally permeable substances across the epithelium. Water permeabilities in intact whole rabbit Bladders were indistinguishable from those obtained in the dissected epithelial preparation. Moreover, addition of nystatin to the apical solution of dissected epithelia rapidly increased water Permeability in conjunction with loss of epithelial resistance. These results confirm that the apical membrane of the Bladder epithelial cells represents the Bladder Permeability barrier. In addition, they establish a model system that will permit examination of how membrane structure reduces Permeability and how epithelial injury compromises barrier function.
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Permeability properties of the mammalian Bladder apical membrane
American Journal of Physiology-cell Physiology, 1994Co-Authors: A Chang, Timothy G Hammond, Tungtien Sun, Mark L ZeidelAbstract:The luminal surface of mammalian Bladder is exposed to urine with a composition widely different from that of plasma that bathes the basolateral surface of epithelium. Therefore we predict that the Bladder Permeability barrier, which is likely located in the apical membrane (AM), will exhibit low permeabilities to water, urea, NH3, H+, and small nonelectrolytes. AM surface area increases as the Bladder fills with urine and decreases during emptying, a process that involves cyclical endocytosis and reinsertion of membrane from a pool of AM endosomes (AME). Rigid-appearing plaques composed of three proteins, uroplakins, have been identified and occupy 70-90% of AM surface area. To determine Permeability properties of the AM Permeability barrier, we purified AME and measured their permeabilities. Rabbit urinary Bladders were removed, and their apical surface was exposed to carboxyfluorescein (CF) or horseradish peroxidase (HRP). Exposure to hypotonic and then isotonic basolateral solutions induced endocytosis of luminal CF or HRP into AME. Electron microscopy of Bladders after this treatment revealed HRP entrapped within AME bordered by plaques. AME were purified by differential and sucrose-gradient centrifugation, and CF-containing AME were purified 17.0 +/- 3-fold (SD) with respect to homogenate. Analysis of purified AME by flow cytometry showed that > 95% of vesicles contained CF entrapped from luminal solution and were selectively labeled with anti-uroplakin antibody. AME osmotic water Permeability averaged 2.3 +/- 0.66 x 10(-4) cm/s and exhibited a high activation energy, indicating that AM contains no water channels. Permeability to urea and NH3 averaged 7.8 +/- 3.7 x 10(-7) and 1.5 +/- 0.3 x 10(-3) cm/s, respectively, which are exceptionally low and similar to permeabilities of other water-tight membranes, including toad urinary Bladder and gastric mucosa. AME behaved as a single population in all Permeability studies, which will permit future characterization of protein and lipid structure responsible for these unique Permeability properties.
Nataliya Smith - One of the best experts on this subject based on the ideXlab platform.
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supergag biopolymers for treatment of excessive Bladder Permeability
Pharmacology Research & Perspectives, 2021Co-Authors: Rheal A Towner, Nataliya Smith, Debra Saunders, Ehsan Mohammadi, Beverley Greenwoodvan Meerveld, Grannum R Sant, Harrison C Shain, Thomas H Jozefiak, Robert E HurstAbstract:Few therapeutic options exist for treatment of IC/BPS. A novel high MW GAG biopolymer ("SuperGAG") was synthesized by controlled oligomerization of CS, purified by TFF and characterized by SEC-MALLS and 1H-NMR spectroscopy. The modified GAG biopolymer was tested in an OVX female rat model in which Bladder Permeability was induced by a 10-minute intravesicular treatment with dilute (1 mg/ml) protamine sulfate and measured by classical Ussing Chamber TEER measurements following treatment with SuperGAG, chondroitin sulfate, or saline. The effect on abrogating the abdominal pain response was assessed using von Frey filaments. The SuperGAG biopolymer was then investigated in a second, genetically modified mouse model (URO-MCP1) that increasingly is accepted as a model for IC/BPS. Permeability was induced with a brief exposure to a sub-noxious dose of LPS and was quantified using contrast-enhanced MRI (CE-MRI). The SuperGAG biopolymer restored imPermeability to normal levels in the OVX rat model as measured by TEER in the Ussing chamber and reduced the abdominal pain response arising from induced Permeability. Evaluation in the URO-MCP1 mouse model also showed restoration of Bladder imPermeability and showed the utility of CE-MRI imaging for evaluating the efficacy of agents to restore Bladder imPermeability. We conclude novel high MW SuperGAG biopolymers are effective in restoring urothelial imPermeability and reducing pain produced by loss of the GAG layer on the urothelium. SuperGAG biopolymers could offer a novel and effective new therapy for IC/BPS, particularly if combined with MRI to assess the efficacy of the therapy.
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in vivo and ex vivo assessment of Bladder hyper Permeability and using molecular targeted magnetic resonance imaging to detect claudin 2 in a mouse model for interstitial cystitis
PLOS ONE, 2020Co-Authors: Nataliya Smith, Debra Saunders, Ehsan Mohammadi, Megan R Lerner, Michelle Zalles, Nadezda Mamedova, Daniel Cheong, Tian Yuan, Yi LuoAbstract:Objectives To determine if the URO-MCP-1 mouse model for Bladder IC/BPS is associated with in vivo Bladder hyper-Permeability, as measured by contrast-enhanced MRI (CE-MRI), and assess whether molecular-targeted MRI (mt-MRI) can visualize in vivo claudin-2 expression as a result of Bladder hyper-Permeability. Interstitial cystitis/Bladder pain syndrome (IC/BPS) is a chronic, painful condition of the Bladder that affects primarily women. It is known that Permeability plays a substantial role in IC/BPS. Claudins are tight junction membrane proteins that are expressed in epithelia and endothelia and form paracellular barriers and pores that determine tight junction Permeability. Claudin-2 is a molecular marker that is associated with increased hyperPermeability in the urothelium. Materials and methods CE-MRI was used to measure Bladder hyper-Permeability in the URO-MCP-1 mice. A claudin-2-specific mt-MRI probe was used to assess in vivo levels of claudin-2. The mt-MRI probe consists of an antibody against claudin-2 conjugated to albumin that had Gd-DTPA (gadolinium diethylenetriamine pentaacetate) and biotin attached. Verification of the presence of the mt-MRI probe was done by targeting the biotin moiety for the probe with streptavidin-horse radish peroxidase (SA-HRP). Trans-epithelial electrical resistance (TEER) was also used to assess Bladder Permeability. Results The URO-MCP-1 mouse model for IC/BPS was found to have a significant increase in Bladder Permeability, following liposaccharide (LPS) exposure, compared to saline-treated controls. mt-MRI- and histologically-detectable levels of the claudin-2 probe were found to increase with LPS -induced Bladder urothelial hyper-Permeability in the URO-MCP-1 IC mouse model. Levels of protein expression for claudin-2 were confirmed with immunohistochemistry and immunofluorescence imaging. Claudin-2 was also found to highly co-localize with zonula occlidens-1 (ZO-1), a tight junction protein. Conclusion The combination of CE-MRI and TEER approaches were able to demonstrate hyper-Permeability, a known feature associated with some IC/BPS patients, in the LPS-exposed URO-MCP-1 mouse model. This MRI approach could be clinically translated to establish which IC/BPS patients have Bladder hyper-Permeability and help determine therapeutic options. In addition, the in vivo molecular-targeted imaging approach can provide invaluable information to enhance our understanding associated with Bladder urothelium hyper-Permeability in IC/BPS patients, and perhaps be used to assist in developing further therapeutic strategies.
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assessing Bladder hyper Permeability biomarkers in vivo using molecularly targeted mri
American journal of nuclear medicine and molecular imaging, 2020Co-Authors: Rheal A Towner, Nataliya Smith, Debra Saunders, Beverley Greenwoodvan Meerveld, Megan R Lerner, Robert E HurstAbstract:The objective was to investigate if some of the key molecular players associated with Bladder hyper-Permeability in interstitial cystitis/Bladder pain syndrome (IC/BPS) could be visualized with molecularly-targeted magnetic resonance imaging (mt-MRI) in vivo. IC/BPS is a chronic, painful condition of the Bladder that affects primarily women. It has been demonstrated over the past several decades that Permeability plays a substantial role in IC/BPS. There are several key molecular markers that have been associated with Permeability, including glycolsaminoglycan (GAG), biglycan, chondroitin sulfate, decorin, E-cadherin, keratin 20, uroplakin, vascular endothelial growth factor receptor 1 (VEGF-R1), claudin-2 and zonula occludens-1 (ZO-1). We used in vivo molecularly-targeted MRI (mt-MRI) to assess specific urothelial biomarkers (decorin, VEGF-R1, and claudin-2) associated with Bladder hyper-Permeability in a protamine sulfate (PS)-induced rat model. The mt-MRI probes consisted of an antibody against either VEGF-R1, decorin or claudin-2 conjugated to albumin that had also Gd-DTPA (gadolinium diethylene triamine penta acetic acid) and biotin attached. mt-MRI- and histologically-detectable levels of decorin and VEGF-R1 were both found to decrease following PS-induced Bladder urothelial hyper-Permeability, whereas claudin-2, was found to increase in the rat PS model. Verification of the presence of the mt-MRI probes were done by targeting the biotin moiety for each respective probe with streptavidin-hose radish peroxidase (HRP). Levels of protein expression for VEGF-R1, decorin and claudin-2 were confirmed with immunohistochemistry. In vivo molecularly-targeted MRI (mt-MRI) was found to successfully detect alterations in the expression of decorin, VEGFR1 and claudin-2 in a PS-induced rat Bladder Permeability model. This in vivo molecularly-targeted imaging approach has the potential to provide invaluable information to enhance our understanding of Bladder urothelium hyper-Permeability in IC/BPS patients, and perhaps be used to assist in developing novel therapeutic strategies.
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in vivo detection of Bladder Permeability biomarkers in rodent models using molecular targeted mri
Free Radical Biology and Medicine, 2018Co-Authors: Rheal A Towner, Nataliya Smith, Debra SaundersAbstract:Bladder Permeability is associated with interstitial cystitis (IC). We previously used contrast-enhanced MRI to assess Bladder Permeability in a protamine sulfate (PS)-Bladder Permeability induced rat model, as well as in human patients for IC. This study focuses on the use of molecular-targeted MRI (mtMRI) to assess Bladder Permeability biomarkers in vivo in rodent Bladder Permeability models. Decorin, VEGFR1 (vascular endothelial growth factor receptor 1), and claudin-2 are all known Bladder urothelium markers. Rats (treated with PS)/mice (URO-MCP-1 transgenic treated with lipopolysaccharide (LPS)) were anesthetized with isoflurane for either intravesical PS/LPS or saline administration, and for MRI scans. Targeted contrast agent probes for claudin-2, VEGFR1 or decorin were used to obtain Bladder Permeability biomarker specific images. Multiple Bladder region MR image slices were taken. Pixel-by-pixel relaxation maps were reconstructed from a series of T1-weighted images using a nonlinear two-parameter fitting procedure. The T1 value of a specified region-of-interest (ROI) was computed from all the pixels in the identified ROIs. mtMRI was able to demonstrate altered levels of claudin-2 (Rat PS and URO-MCP-1 mouse LPS models), VEGFR1 and decorin in PS-induced permeable rat Bladders, compared to saline-treated controls. Data indicates the feasibility of conducting in vivo mtMR imaging for the Bladder Permeability biomarker claudin-2 in PS-exposed rat Bladders. Claudin-2 levels are significantly increased (p
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preclinical animal studies of intravesical recombinant human proteoglycan 4 as a novel potential therapy for diseases resulting from increased Bladder Permeability
Urology, 2018Co-Authors: Nataliya Smith, Ehsan Mohammadi, Beverley Greenwoodvan Meerveld, Rocco Latorre, Edward R Truitt, Gregory D Jay, Benjamin Sullivan, Tannin A Schmidt, Debra SaundersAbstract:Objective To test in an animal model the hypothesis that recombinant human proteoglycan 4 (rhPRG4; lubricin), a highly O-glycosylated mucin-like glycoprotein, may be a novel surface-active therapeutic for treating Bladder Permeability with comorbid bowel Permeability. Previously we showed that inducing Bladder Permeability in rats with dilute protamine sulfate (PS) produced colonic Permeability and visceral hypersensitivity, suggesting increased Bladder Permeability could represent an etiologic factor in both interstitial cystitis-Bladder pain syndrome and irritable bowel syndrome. Methods We used an animal model of catheterized ovariectomized female rats instilled intravesically with 1 mg/mL PS for 10 minutes that after 24 hours were treated with 1.2 mg/mL lubricin or with vehicle alone. After 24 hours the Bladder and colon were removed and Permeability assessed electrophysiologically with the Ussing chamber to measure the transepithelial electrical resistance. A second set of rats was treated identically, except Permeability was assessed on day 3 and on day 5 using contrast-enhanced magnetic resonance imaging with gadolinium diethylenetriamine penta-acetic acid instilled into the Bladder. Results Intravesical lubricin reversed Bladder Permeability induced by PS and prevented the concomitant increase in Permeability induced in the bowel (organ crosstalk). The protective effect was confirmed with magnetic resonance imaging, and because individual rats could be followed over time, the imPermeability of the Bladder restored by rhPRG4 remained for 5 days. Conclusion These data indicate that instillation of rhPRG4 into a permeable Bladder can restore its normally impermeable state, and that the effect lasts for 5 days and also prevents bowel symptoms often comorbid with interstitial cystitis-Bladder pain syndrome.
Debra Saunders - One of the best experts on this subject based on the ideXlab platform.
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supergag biopolymers for treatment of excessive Bladder Permeability
Pharmacology Research & Perspectives, 2021Co-Authors: Rheal A Towner, Nataliya Smith, Debra Saunders, Ehsan Mohammadi, Beverley Greenwoodvan Meerveld, Grannum R Sant, Harrison C Shain, Thomas H Jozefiak, Robert E HurstAbstract:Few therapeutic options exist for treatment of IC/BPS. A novel high MW GAG biopolymer ("SuperGAG") was synthesized by controlled oligomerization of CS, purified by TFF and characterized by SEC-MALLS and 1H-NMR spectroscopy. The modified GAG biopolymer was tested in an OVX female rat model in which Bladder Permeability was induced by a 10-minute intravesicular treatment with dilute (1 mg/ml) protamine sulfate and measured by classical Ussing Chamber TEER measurements following treatment with SuperGAG, chondroitin sulfate, or saline. The effect on abrogating the abdominal pain response was assessed using von Frey filaments. The SuperGAG biopolymer was then investigated in a second, genetically modified mouse model (URO-MCP1) that increasingly is accepted as a model for IC/BPS. Permeability was induced with a brief exposure to a sub-noxious dose of LPS and was quantified using contrast-enhanced MRI (CE-MRI). The SuperGAG biopolymer restored imPermeability to normal levels in the OVX rat model as measured by TEER in the Ussing chamber and reduced the abdominal pain response arising from induced Permeability. Evaluation in the URO-MCP1 mouse model also showed restoration of Bladder imPermeability and showed the utility of CE-MRI imaging for evaluating the efficacy of agents to restore Bladder imPermeability. We conclude novel high MW SuperGAG biopolymers are effective in restoring urothelial imPermeability and reducing pain produced by loss of the GAG layer on the urothelium. SuperGAG biopolymers could offer a novel and effective new therapy for IC/BPS, particularly if combined with MRI to assess the efficacy of the therapy.
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in vivo and ex vivo assessment of Bladder hyper Permeability and using molecular targeted magnetic resonance imaging to detect claudin 2 in a mouse model for interstitial cystitis
PLOS ONE, 2020Co-Authors: Nataliya Smith, Debra Saunders, Ehsan Mohammadi, Megan R Lerner, Michelle Zalles, Nadezda Mamedova, Daniel Cheong, Tian Yuan, Yi LuoAbstract:Objectives To determine if the URO-MCP-1 mouse model for Bladder IC/BPS is associated with in vivo Bladder hyper-Permeability, as measured by contrast-enhanced MRI (CE-MRI), and assess whether molecular-targeted MRI (mt-MRI) can visualize in vivo claudin-2 expression as a result of Bladder hyper-Permeability. Interstitial cystitis/Bladder pain syndrome (IC/BPS) is a chronic, painful condition of the Bladder that affects primarily women. It is known that Permeability plays a substantial role in IC/BPS. Claudins are tight junction membrane proteins that are expressed in epithelia and endothelia and form paracellular barriers and pores that determine tight junction Permeability. Claudin-2 is a molecular marker that is associated with increased hyperPermeability in the urothelium. Materials and methods CE-MRI was used to measure Bladder hyper-Permeability in the URO-MCP-1 mice. A claudin-2-specific mt-MRI probe was used to assess in vivo levels of claudin-2. The mt-MRI probe consists of an antibody against claudin-2 conjugated to albumin that had Gd-DTPA (gadolinium diethylenetriamine pentaacetate) and biotin attached. Verification of the presence of the mt-MRI probe was done by targeting the biotin moiety for the probe with streptavidin-horse radish peroxidase (SA-HRP). Trans-epithelial electrical resistance (TEER) was also used to assess Bladder Permeability. Results The URO-MCP-1 mouse model for IC/BPS was found to have a significant increase in Bladder Permeability, following liposaccharide (LPS) exposure, compared to saline-treated controls. mt-MRI- and histologically-detectable levels of the claudin-2 probe were found to increase with LPS -induced Bladder urothelial hyper-Permeability in the URO-MCP-1 IC mouse model. Levels of protein expression for claudin-2 were confirmed with immunohistochemistry and immunofluorescence imaging. Claudin-2 was also found to highly co-localize with zonula occlidens-1 (ZO-1), a tight junction protein. Conclusion The combination of CE-MRI and TEER approaches were able to demonstrate hyper-Permeability, a known feature associated with some IC/BPS patients, in the LPS-exposed URO-MCP-1 mouse model. This MRI approach could be clinically translated to establish which IC/BPS patients have Bladder hyper-Permeability and help determine therapeutic options. In addition, the in vivo molecular-targeted imaging approach can provide invaluable information to enhance our understanding associated with Bladder urothelium hyper-Permeability in IC/BPS patients, and perhaps be used to assist in developing further therapeutic strategies.
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assessing Bladder hyper Permeability biomarkers in vivo using molecularly targeted mri
American journal of nuclear medicine and molecular imaging, 2020Co-Authors: Rheal A Towner, Nataliya Smith, Debra Saunders, Beverley Greenwoodvan Meerveld, Megan R Lerner, Robert E HurstAbstract:The objective was to investigate if some of the key molecular players associated with Bladder hyper-Permeability in interstitial cystitis/Bladder pain syndrome (IC/BPS) could be visualized with molecularly-targeted magnetic resonance imaging (mt-MRI) in vivo. IC/BPS is a chronic, painful condition of the Bladder that affects primarily women. It has been demonstrated over the past several decades that Permeability plays a substantial role in IC/BPS. There are several key molecular markers that have been associated with Permeability, including glycolsaminoglycan (GAG), biglycan, chondroitin sulfate, decorin, E-cadherin, keratin 20, uroplakin, vascular endothelial growth factor receptor 1 (VEGF-R1), claudin-2 and zonula occludens-1 (ZO-1). We used in vivo molecularly-targeted MRI (mt-MRI) to assess specific urothelial biomarkers (decorin, VEGF-R1, and claudin-2) associated with Bladder hyper-Permeability in a protamine sulfate (PS)-induced rat model. The mt-MRI probes consisted of an antibody against either VEGF-R1, decorin or claudin-2 conjugated to albumin that had also Gd-DTPA (gadolinium diethylene triamine penta acetic acid) and biotin attached. mt-MRI- and histologically-detectable levels of decorin and VEGF-R1 were both found to decrease following PS-induced Bladder urothelial hyper-Permeability, whereas claudin-2, was found to increase in the rat PS model. Verification of the presence of the mt-MRI probes were done by targeting the biotin moiety for each respective probe with streptavidin-hose radish peroxidase (HRP). Levels of protein expression for VEGF-R1, decorin and claudin-2 were confirmed with immunohistochemistry. In vivo molecularly-targeted MRI (mt-MRI) was found to successfully detect alterations in the expression of decorin, VEGFR1 and claudin-2 in a PS-induced rat Bladder Permeability model. This in vivo molecularly-targeted imaging approach has the potential to provide invaluable information to enhance our understanding of Bladder urothelium hyper-Permeability in IC/BPS patients, and perhaps be used to assist in developing novel therapeutic strategies.
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in vivo detection of Bladder Permeability biomarkers in rodent models using molecular targeted mri
Free Radical Biology and Medicine, 2018Co-Authors: Rheal A Towner, Nataliya Smith, Debra SaundersAbstract:Bladder Permeability is associated with interstitial cystitis (IC). We previously used contrast-enhanced MRI to assess Bladder Permeability in a protamine sulfate (PS)-Bladder Permeability induced rat model, as well as in human patients for IC. This study focuses on the use of molecular-targeted MRI (mtMRI) to assess Bladder Permeability biomarkers in vivo in rodent Bladder Permeability models. Decorin, VEGFR1 (vascular endothelial growth factor receptor 1), and claudin-2 are all known Bladder urothelium markers. Rats (treated with PS)/mice (URO-MCP-1 transgenic treated with lipopolysaccharide (LPS)) were anesthetized with isoflurane for either intravesical PS/LPS or saline administration, and for MRI scans. Targeted contrast agent probes for claudin-2, VEGFR1 or decorin were used to obtain Bladder Permeability biomarker specific images. Multiple Bladder region MR image slices were taken. Pixel-by-pixel relaxation maps were reconstructed from a series of T1-weighted images using a nonlinear two-parameter fitting procedure. The T1 value of a specified region-of-interest (ROI) was computed from all the pixels in the identified ROIs. mtMRI was able to demonstrate altered levels of claudin-2 (Rat PS and URO-MCP-1 mouse LPS models), VEGFR1 and decorin in PS-induced permeable rat Bladders, compared to saline-treated controls. Data indicates the feasibility of conducting in vivo mtMR imaging for the Bladder Permeability biomarker claudin-2 in PS-exposed rat Bladders. Claudin-2 levels are significantly increased (p
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preclinical animal studies of intravesical recombinant human proteoglycan 4 as a novel potential therapy for diseases resulting from increased Bladder Permeability
Urology, 2018Co-Authors: Nataliya Smith, Ehsan Mohammadi, Beverley Greenwoodvan Meerveld, Rocco Latorre, Edward R Truitt, Gregory D Jay, Benjamin Sullivan, Tannin A Schmidt, Debra SaundersAbstract:Objective To test in an animal model the hypothesis that recombinant human proteoglycan 4 (rhPRG4; lubricin), a highly O-glycosylated mucin-like glycoprotein, may be a novel surface-active therapeutic for treating Bladder Permeability with comorbid bowel Permeability. Previously we showed that inducing Bladder Permeability in rats with dilute protamine sulfate (PS) produced colonic Permeability and visceral hypersensitivity, suggesting increased Bladder Permeability could represent an etiologic factor in both interstitial cystitis-Bladder pain syndrome and irritable bowel syndrome. Methods We used an animal model of catheterized ovariectomized female rats instilled intravesically with 1 mg/mL PS for 10 minutes that after 24 hours were treated with 1.2 mg/mL lubricin or with vehicle alone. After 24 hours the Bladder and colon were removed and Permeability assessed electrophysiologically with the Ussing chamber to measure the transepithelial electrical resistance. A second set of rats was treated identically, except Permeability was assessed on day 3 and on day 5 using contrast-enhanced magnetic resonance imaging with gadolinium diethylenetriamine penta-acetic acid instilled into the Bladder. Results Intravesical lubricin reversed Bladder Permeability induced by PS and prevented the concomitant increase in Permeability induced in the bowel (organ crosstalk). The protective effect was confirmed with magnetic resonance imaging, and because individual rats could be followed over time, the imPermeability of the Bladder restored by rhPRG4 remained for 5 days. Conclusion These data indicate that instillation of rhPRG4 into a permeable Bladder can restore its normally impermeable state, and that the effect lasts for 5 days and also prevents bowel symptoms often comorbid with interstitial cystitis-Bladder pain syndrome.
Robert E Hurst - One of the best experts on this subject based on the ideXlab platform.
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supergag biopolymers for treatment of excessive Bladder Permeability
Pharmacology Research & Perspectives, 2021Co-Authors: Rheal A Towner, Nataliya Smith, Debra Saunders, Ehsan Mohammadi, Beverley Greenwoodvan Meerveld, Grannum R Sant, Harrison C Shain, Thomas H Jozefiak, Robert E HurstAbstract:Few therapeutic options exist for treatment of IC/BPS. A novel high MW GAG biopolymer ("SuperGAG") was synthesized by controlled oligomerization of CS, purified by TFF and characterized by SEC-MALLS and 1H-NMR spectroscopy. The modified GAG biopolymer was tested in an OVX female rat model in which Bladder Permeability was induced by a 10-minute intravesicular treatment with dilute (1 mg/ml) protamine sulfate and measured by classical Ussing Chamber TEER measurements following treatment with SuperGAG, chondroitin sulfate, or saline. The effect on abrogating the abdominal pain response was assessed using von Frey filaments. The SuperGAG biopolymer was then investigated in a second, genetically modified mouse model (URO-MCP1) that increasingly is accepted as a model for IC/BPS. Permeability was induced with a brief exposure to a sub-noxious dose of LPS and was quantified using contrast-enhanced MRI (CE-MRI). The SuperGAG biopolymer restored imPermeability to normal levels in the OVX rat model as measured by TEER in the Ussing chamber and reduced the abdominal pain response arising from induced Permeability. Evaluation in the URO-MCP1 mouse model also showed restoration of Bladder imPermeability and showed the utility of CE-MRI imaging for evaluating the efficacy of agents to restore Bladder imPermeability. We conclude novel high MW SuperGAG biopolymers are effective in restoring urothelial imPermeability and reducing pain produced by loss of the GAG layer on the urothelium. SuperGAG biopolymers could offer a novel and effective new therapy for IC/BPS, particularly if combined with MRI to assess the efficacy of the therapy.
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assessing Bladder hyper Permeability biomarkers in vivo using molecularly targeted mri
American journal of nuclear medicine and molecular imaging, 2020Co-Authors: Rheal A Towner, Nataliya Smith, Debra Saunders, Beverley Greenwoodvan Meerveld, Megan R Lerner, Robert E HurstAbstract:The objective was to investigate if some of the key molecular players associated with Bladder hyper-Permeability in interstitial cystitis/Bladder pain syndrome (IC/BPS) could be visualized with molecularly-targeted magnetic resonance imaging (mt-MRI) in vivo. IC/BPS is a chronic, painful condition of the Bladder that affects primarily women. It has been demonstrated over the past several decades that Permeability plays a substantial role in IC/BPS. There are several key molecular markers that have been associated with Permeability, including glycolsaminoglycan (GAG), biglycan, chondroitin sulfate, decorin, E-cadherin, keratin 20, uroplakin, vascular endothelial growth factor receptor 1 (VEGF-R1), claudin-2 and zonula occludens-1 (ZO-1). We used in vivo molecularly-targeted MRI (mt-MRI) to assess specific urothelial biomarkers (decorin, VEGF-R1, and claudin-2) associated with Bladder hyper-Permeability in a protamine sulfate (PS)-induced rat model. The mt-MRI probes consisted of an antibody against either VEGF-R1, decorin or claudin-2 conjugated to albumin that had also Gd-DTPA (gadolinium diethylene triamine penta acetic acid) and biotin attached. mt-MRI- and histologically-detectable levels of decorin and VEGF-R1 were both found to decrease following PS-induced Bladder urothelial hyper-Permeability, whereas claudin-2, was found to increase in the rat PS model. Verification of the presence of the mt-MRI probes were done by targeting the biotin moiety for each respective probe with streptavidin-hose radish peroxidase (HRP). Levels of protein expression for VEGF-R1, decorin and claudin-2 were confirmed with immunohistochemistry. In vivo molecularly-targeted MRI (mt-MRI) was found to successfully detect alterations in the expression of decorin, VEGFR1 and claudin-2 in a PS-induced rat Bladder Permeability model. This in vivo molecularly-targeted imaging approach has the potential to provide invaluable information to enhance our understanding of Bladder urothelium hyper-Permeability in IC/BPS patients, and perhaps be used to assist in developing novel therapeutic strategies.
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su g iep1 10 Permeability evaluation of interstitial cystitis by dce mri of the Bladder
Medical Physics, 2016Co-Authors: Justin C North, Rheal A Towner, Robert E HurstAbstract:Purpose: Interstitial cystitis (IC) is a chronic and painful condition that can lead to Bladder pain syndrome (BPS) in women. IC and BPS have been known to manifest after physiological changes after giving birth. In this project, we pioneered and advanced a new clinical utility using DCE-MRI to assess Bladder Permeability. At first IC/BPS perfusion methods were with ratio signal evaluation, we now incorporate pharmacokinetics techniques to allow for further assessment. Methods: In this pilot study, female patients and volunteers (IC=4, Control=3) underwent imaging with a clinical GE 3T 750W MRI system. This project was approved by the OUHSC IRB. Multiple TR Images series were acquired. Images were analyzed in the coronal plane at 0-, 3-, 6-, 9-, 12-, 15-, 20-, 25-, and 30-minute intervals. We used a three-compartmental pharmacokinetic model with these data. The compartments included: a) Bladder interior site of injection, b) Bladder wall, and c) external psoas muscle. The signal was transformed and corrected for T1-relaxation based on a multi-TR exponential regression before pharmacokinetic analysis. Results: Significant differences (p<0.05) were detected with relative means for T1 concentration changes (IC/BPS=0.0107, control=0.616) on the outflow between the k13 transfer coefficient, which represents the injection leakage to the external parenchyma. Trend differences (p<0.1) were found in Permeability between the Bladder injection site to the rim. We also found changes in the kurtosis of the histograms of regional perfusion. No detectable changes were found in the reverse directions for the above compartments (k21, k31). Conclusion: We report clinical changes in this pilot study. This study illustrates early detectable evidence for a possible DCE-MRI tool that can detect Permeability differences with pharmacokinetics measurement of k13. These techniques are intended to advance quantitative imaging methods for IC/BPS, per the goals/objectives of the Quantitative Imaging Biomarker Alliance (QIBA) and other AAPM and RSNA initiatives.
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in the absence of overt urothelial damage chondroitinase abc digestion of the gag layer increases Bladder Permeability in ovariectomized female rats
American Journal of Physiology-renal Physiology, 2016Co-Authors: Robert E Hurst, Rheal A Towner, Samuel Van Gordon, Bradley P Kropp, Hsueh Kung Lin, Karl Tyler, John O Marentette, Jane Mchowat, Ehsan Mohammedi, Beverley Greenwoodvan MeerveldAbstract:Loss of integrity of the protective imPermeability barrier in the urothelium has been identified as significant in Bladder dysfunction. In this study, we tested the theory that the luminal layer of...
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increased Bladder Permeability in interstitial cystitis painful Bladder syndrome
Translational Andrology and Urology, 2015Co-Authors: Robert E Hurst, Beverley Greenwoodvan Meerveld, Amy B Wisniewski, Bradley P Kropp, Samuel Vangordon, Hsueh Kung Lin, Rheal A TownerAbstract:The definition of interstitial cystitis (IC) has evolved over the years from being a well-defined entity characterized by diagnostic lesion (Hunner’s ulcer) in the urothelium to a clinical diagnosis by exclusion [painful Bladder syndrome (PBS)]. Although the etiology is unknown, a central theme has been an association with increased Permeability of the Bladder. This article reviews the evidence for increased Permeability being important to the symptoms of interstitial cystitis/painful Bladder syndrome (IC/PBS) and in treating the disorder. Recent work showing cross-communication among visceral organs is also reviewed to provide a basis for understanding IC/PBS as a systemic disorder of a complex, interconnected system consisting of the Bladder, bowel and other organs, nerves, cytokine-responding cells and the nervous system.