Preferential localization of 3H-pentosanpolysulphate to the urinary tract in rats

Mechanism of Porphyra Yezoensis Polysaccharides in Inhibiting Hyperoxalate-Induced Renal Injury and Crystal Deposition

Oxidative damage to the kidneys is a primary factor in the occurrence of kidney stones. This study explores the inhibitory effect of Porphyra yezoensis polysaccharides (PYP) on oxalate-induced renal injury by detecting levels of oxidative damage, expression of adhesion molecules, and damage to intracellular organelles and revealed the molecular mechanism by molecular biology methods. Additionally, we validated the role of PYP in vivo using a crystallization model of hyperoxalate-induced rats. PYP effectively scavenged the overproduction of reactive oxygen species (ROS) in HK-2 cells, inhibited the adhesion of calcium oxalate (CaOx) crystals on the cell surface, unblocked the cell cycle, restored the depolarization of the mitochondrial membrane potential, and inhibited cell death. PYP upregulated the expression of antioxidant proteins, including Nrf2, HO-1, SOD, and CAT, while decreasing the expression of Keap-1, thereby activating the Keap1/Nrf2 signaling pathway. PYP inhibited CaOx deposition in renal tubules in the rat crystallization model, significantly reduced high oxalate-induced renal injury, decreased the levels of the cell surface adhesion proteins, improved renal function in rats, and ultimately inhibited the formation of kidney stones. Therefore, PYP, which has crystallization inhibition and antioxidant properties, may be a therapeutic option for the treatment of kidney stones.

A post-trial follow-up study of pentosan polysulfate monotherapy on preventing recurrent urinary tract infection in women

For women with recurrent urinary tract infection (UTI), previous U101 study has shown that pentosan polysulfate sodium (PPS) monotherapy for 16 weeks significantly reduced UTI episodes in the treatment group throughout the trial period. In this follow-up study, we aimed to assess whether the effects of PPS would last after completion of the trial to prevent recurrent UTIs. Conducted from 2018 to 2019, the U101 study was a multicenter, prospective, phase 2a, randomized trial, enrolling women with recurrent UTI to study the effects of a 16-week oral PPS monotherapy. After approximately two years, the follow-up was conducted by phone interview, obtaining data including self-reported UTI events, quality of life questionnaire, and adverse events. The primary endpoint of follow-up study was UTI recurrence-free survival and the secondary endpoints were quality of life and adverse events. Approximately two years after completion of the trial, the rate of recurrent UTI was 25% (3 of the 12 patients) in the PPS group and 85.7% (12 of the 14 patients) in the control group. Over the entire follow-up period, the UTI recurrence-free survival was significantly better in the PPS group than in the control group (log-rank test p < 0.001). The quality of life at two years was significantly improved in the PPS when compared to the control group (91.7 vs. 77.5, p < 0.001). No late adverse event was observed after cessation of the treatment. In this study, sixteen weeks of PPS monotherapy in women with recurrent UTI significantly reduced the numbers of recurrent UTI episodes during the 2-year follow-up.

Regulatory Effects of Damaged Renal Epithelial Cells After Repair by Porphyra yezoensis Polysaccharides with Different Sulfation Degree on the Calcium Oxalate Crystal-Cell Interaction

BACKGROUND

The interaction between urinary microcrystals and renal epithelial cells is closely related to kidney stone formation. However, the mechanism of cell state changes that affect crystal-cell interaction remains unclear.

METHODS

This study investigated the relationship between the sulfate group (-OSO3 -) content in Porphyra yezoensis polysaccharide (PYP) and the ability to repair damaged cells, as well as the changes in cell adhesion and endocytosis of nano-calcium oxalate monohydrate (COM) crystals before and after PYP repair of damaged renal tubular epithelial cells. The sulfur trioxide-pyridine method was used to sulfate PYP (-OSO3 - content of 14.14%), and two kinds of sulfated PYPs with -OSO3 - content of 20.28% (SPYP1) and 27.14% (SPYP2) were obtained. The above three PYPs were used to repair oxalate-damaged human proximal tubular epithelial cells (HK-2), and the changes in the biochemical indicators of the cells before and after the repair and the changes in cell adhesion and endocytosis of nano-COM crystals were detected.

RESULTS

After repair by PYPs, the cell viability increased, the number of reactive oxygen species decreased, and the reduction of mitochondrial membrane potential and the release of intracellular Ca2+ were suppressed. The cells repaired by PYPs inhibited the adhesion of nano-COM crystals while promoting the endocytosis of the adhered crystals. The endocytosed crystals mainly accumulated in the lysosome. The ability of PYPs to repair cell damage, inhibit crystal adhesion, and promote crystal endocytosis was enhanced when the -OSO3 - content increased. Among them, SPYP2 with the highest -OSO3 - content showed the best biological activity.

CONCLUSION

SPYP2 showed the best ability to repair damaged cells, followed by SPYP1 and PYP. SPYP2 may become a potential green drug that inhibits the formation and recurrence of calcium oxalate stones.

Repair activity and crystal adhesion inhibition of polysaccharides with different molecular weights from red algae Porphyra yezoensis against oxalate-induced oxidative damage in renal epithelial cells

Porphyra yezoensis polysaccharide repaired oxalate-injured renal epithelial cells and decreased COM crystal adhesion on the cell surface.

Broad Th2 neutralization and anti-inflammatory action of pentosan polysulfate sodium in experimental allergic rhinitis

Background

Th2 cytokines like interleukin‐4, ‐5, and ‐13 are regarded as important drivers of the immunopathology underlying allergic rhinitis (AR) and asthma. The present study explores the capacity of pentosan polysulfate sodium (PPS), a semi‐synthetic heparin‐like macromolecular carbohydrate, to bind Th2 cytokines and exert biological neutralization in vitro, as well as anti‐inflammatory actions in vivo.

Methodology

The capacity of PPS to bind recombinant Th2 cytokines was tested with surface plasmon resonance (SPR) technology and biological Th2 neutralization was assessed by Th2‐dependent proliferation assays. The in vivo anti‐inflammatory action of PPS was studied using a validated Guinea‐pig model of AR.

Results

Binding studies revealed a strong and specific binding of PPS to IL‐4, IL‐5, and IL‐13 with IC values suggesting as stronger cytokine binding than for heparin. Cytokine binding translated to a biological neutralization as PPS dose dependently inhibited Th2‐dependent cell proliferation. Topical administration of PPS 30 min prior to nasal allergen challenge of sensitized animals significantly reduced late phase plasma extravasation, luminal influx of eosinophils, neutrophils, and total lavage leukocytes. Similar, albeit not statistically secured, effects were found for tissue leukocytes and mucus hyper‐secretion. The anti‐inflammatory effects of PPS compared favorably with established topical nasal steroid treatment.

Conclusion

This study points out PPS as a potent Th2 cytokine‐binding molecule with biological neutralization capacity and broad anti‐inflammatory effects in vivo. As such PPS fulfills the role as a potential candidate molecule for the treatment of AR and further studies of clinical efficacy seems highly warranted.

Metabolism of [3H]pentosan polysulfate sodium (PPS) in healthy human volunteers

Pentosan polysulfate sodium (PPS) is the active ingredient in ELMIRON, a drug approved for the relief of bladder pain associated with interstitial cystitis. The study objective was to characterize the pharmacokinetic and metabolic profiles of PPS following oral dosing of [3H]PPS. As specific assays for PPS do not exist, metabolic profiling was accomplished through multiple fraction collections and radiochromatographic techniques. Two groups of eight healthy female subjects sequentially received a single oral dose of 200 microCi [3H]PPS supplemented with 300 mg unlabelled PPS or 300 microCi [3H]PPS supplemented with 450 mg unlabelled PPS. Most of the administered dose (84%) was excreted in faeces as intact PPS, and a smaller percentage (6%) was excreted in urine. In summary, orally administered PPS was very poorly absorbed, with the majority of the drug being excreted in faeces as intact PPS and in urine as low molecular weight and desulfated PPS.

A novel role of fibroblast growth factor-2 and pentosan polysulfate in the pathogenesis of intestinal bleeding in mice

Pentosan polysulfate (PPS) is a heparin-like polysaccharide that can affect the binding interactions of fibroblast growth factor (FGF-2) with its high-affinity receptors. Patients with angiogenic tumors frequently show high levels of FGF-2 in the circulation. Since FGF-2 is a heparin-binding angiogenic growth factor, PPS has been used successfully to block its activity in patients with angiogenic tumors. However, because of its heparin-like activity, the major toxic effect of PPS is the development of bleeding disorders. The role that circulating FGF-2 plays in the pathogenesis of bleeding disorders in patients treated with PPS is currently unknown. Here we hypothesized that FGF-2 might play a physiological role in the pathogenesis of intestinal bleeding induced by PPS. This hypothesis is supported by previous studies showing that PPS is accumulated in the intestine and that circulating FGF-2 specifically binds to and modulates the angiogenic activity of intestinal submucosal endothelial cells. We used recombinant adenoviral vectors carrying a secreted form of FGF-2 and LacZ control vectors to determine whether high levels of circulating FGF-2 facilitate the development of intestinal bleeding disorders in FVB/N and C57BL/6J mice treated with PPS. We found that PPS, acting together with FGF-2, induced structural changes in intestinal vessels leading to the development of lethal intestinal hemorrhages. These findings might have wider clinical implications for the systemic use of PPS and other heparinoids in the treatment of patients with angiogenic diseases associated with high levels of circulating FGF-2.

Molecular size affects urine excretion of pentosan polysulfate

PURPOSE

In human subjects only a small percent of oral PPS is found in urine. Commercially available PPS is a heterogeneous mixture with varying molecular weights. Our hypothesis was that only the low molecular weight fraction reaches the urine.

MATERIALS AND METHODS

Urine was obtained from patients with IC who were chronically receiving PPS. The amount and molecular size of PPS in the urine were determined by enzyme-linked immunosorbent assay and molecular sieve chromatography. PPS was purified from Elmiron capsules and fractionated into LMW and HMW fractions. Urine recovery of PPS was measured in rabbits after oral or intravenous administration of unfractionated, LMW or HMW PPS.

RESULTS

The median urine PPS level in 34 patients with IC was 1.2 microg/ml (range 0.5 to 27.7). All PPS recovered from IC urine was LMW. After intravenous administration in rabbits the median recovery in urine was 47.2% (range 19.7% to 73.2%) for unfractionated PPS, 74.6% (range 31.4% to 96.3%) for LMW and 3.3% (range 2.5% to 5.0%) for HMW. After oral administration in rabbits the median recovery in urine was 7.4% (range 2.1% to 46.0%) for LMW and 0.10% (range 0.0% to 0.3%) for HMW.

CONCLUSIONS

In patients with IC who are on oral PPS the PPS recovered in the urine is all of LMW. In rabbits the HMW fraction of PPS is recovered in small amounts from urine after intravenous administration and not at all after oral administration.

Potentiation of carbon tetrachloride hepatotoxicity by pentosan polysulfate in rats

Few data are available in the literature regarding the effect of pentosan polysulfate (PPS) on normal and fibrotic rat livers. In addition, the combination of PPS and carbon tetrachloride (CCl4) has not been studied so far. The objective of this study was to assess the effect of PPS on rat livers treated or not with CCl4 for the induction of liver fibrosis. The study consisted of four stages: 1) hepatic fibrosis induction with CCl4 (N = 36 rats); 2) evaluation of the effect of PPS on CCl4-induced hepatic fibrosis (N = 36 rats); 3) evaluation of the effect of higher doses of PPS in combination with CCl4 (N = 50 rats); 4) evaluation of the presence of an enzymatic inductor effect by PPS (N = 18 rats) using the sodium pentobarbital test which indirectly evaluates hepatic microsomal enzyme activity in vivo. Adult (60 to 70 days) male Wistar rats weighing 180 to 220 g were used. All animals receiving 0.5 ml 8% CCl4 (N = 36) developed hepatic fibrosis, and after 8 weeks they also developed cirrhosis. No delay or prevention of hepatic fibrosis was observed with the administration of 5 mg/kg PPS (N = 8) and 1 mg/kg PPS (N = 8) 1 h after the administration of CCl4, but the increased hepatotoxicity resulting from the combination of the two substances caused massive hepatic necrosis in most rats (N = 45). PPS (40 mg/kg) alone caused hepatic congestion only after 8 weeks, but massive hepatic necrosis was again observed in association with 0.5 ml CCl4 after 1 to 4 weeks of treatment. Unexpectedly, sleeping time increased with time of PPS administration (1, 2, or 3 weeks). This suggests that PPS does not function as an activator of the hepatic microsomal enzymatic system. Further studies are necessary in order to clarify the unexpected increase in hepatotoxicity caused by the combination of CCl4 and high doses of PPS, which results in massive hepatic necrosis.

Effects of C-reactive protein and pentosan polysulphate on human complement activation

Complement (C) activation is believed to play an adverse role in several chronic degenerative disease processes, including atherosclerosis, myocardial infarction and Alzheimer's disease. We developed several in vitro quantitative assays to evaluate processes which activate C in human serum, and to assess candidates which might block that activation. Binding of C-reactive protein (CRP) to immobilized cell surfaces was used as a tissue-based method of activation, while immunoglobulin G in solution was used as a surrogate antibody method. Activation was assessed by deposition of C fragments on fixed cell surfaces, or by capture of C5b-9 from solution. We observed that several cell lines, including SH-SY5Y, U-937, THP-1 and ECV304, bound CRP and activated C following attachment of cells to a plastic surface by means of air drying. Treatment of human neuroblastoma SH-SY5Y cells with the reactive oxygen intermediates generated by xanthine (Xa) - xanthine oxidase (XaOx) prior to air drying or by hydrogen peroxide solutions after air drying, enhanced C activation, possibly through oxidation of the cell lipid membrane. Several C inhibitors were tested for their effectiveness in blocking these systems. Pentosan polysulphate (PPS), an orally active agent, blocked C activation in the same concentration range of 1-1000 microg/ml as heparin, dextran sulphate, compstatin and fucoidan. PPS may have practical application as a C inhibitor.

Increased rat cardiac allograft survival by the glycosaminoglycan pentosan polysulfate

BACKGROUND

Modulation of the inflammatory response has proven to be of benefit in salvaging cardiac allografts at risk of irreversible injury. Pentosan polysulfate (PPS), like heparin, is a negatively charged sulfated glycosaminoglycan (GAG) that possesses anti-inflammatory properties including the ability to inhibit activation of the complement system. This study was conducted to determine the potential of PPS to prolong allograft survival in an experimental model of cardiac transplantation.

MATERIALS AND METHODS

A heterotopic cardiac transplant was performed by implanting the heart from fetal Brown Norway rats into the ear pinnae of adult Lewis rats. Vehicle (saline) or PPS (30 mg/kg) was administered subcutaneously immediately after transplantation and daily thereafter (n = 6 in each group). Another GAG, heparin, was also analyzed to determine the effect of anticoagulation on transplant survival (n = 6).

RESULTS

Treatment with PPS significantly (P < 0. 05) increased allograft survival time as compared to vehicle-treated animals (8.0 +/- 0.3 days vs 5.5 +/- 0.5 days). The results noted with PPS were similar to those observed in cyclosporine (10 mg/kg; n = 6)-treated animals (8.25 +/- 0.25 days). Treatment with heparin (300 U/kg/day) did not significantly prolong cardiac graft survival time, suggesting that anticoagulation is not sufficient to prolong transplant survival. Analysis of tissue histology showed diminished transplant rejection as evidenced by decreased white blood cell infiltration and cellular necrosis.

CONCLUSIONS

The results of this study indicate that PPS possesses the ability to prolong cardiac transplant viability in a heterotopic cardiac transplant model, independent of its anticoagulant actions.

Reduction of myocardial infarct size after ischemia and reperfusion by the glycosaminoglycan pentosan polysulfate

Activation of the complement system contributes to the tissue destruction associated with myocardial ischemia/reperfusion. Pentosan polysulfate (PPS), a negatively charged sulfated glycosaminoglycan (GAG) and an effective inhibitor of complement activation, was studied for its potential to decrease infarct size in an experimental model of myocardial ischemia/reperfusion injury. Open-chest rabbits were subjected to 30-min occlusion of the left coronary artery followed by 5 h of reperfusion. Vehicle (saline) or PPS (30 mg/kg/h) was administered intravenously immediately before the onset of reperfusion and every hour during the reperfusion period. Treatment with PPS significantly (p < 0.05) reduced infarct size as compared with vehicle-treated animals (27.5+/-2.9% vs. 13.34+/-2.6%). Analysis of tissue demonstrated decreased deposition of membrane-attack complex and neutrophil accumulation in the area at risk. The results indicate that, like heparin and related GAGs, PPS possesses the ability to decrease infarct size after an acute period of myocardial ischemia and reperfusion. The observations are consistent with the suggestion that PPS may mediate its cytoprotective effect through modulation of the complement cascade.

The pathobiology of osteoarthritis and the rationale for the use of pentosan polysulfate for its treatment

OBJECTIVES

Structure-modifying osteoarthritis (OA) drugs (SMOADs) may be defined as agents that reverse, retard, or stabilize the underlying pathology of OA, thereby providing symptomatic relief in the long-term. The objective of this review was to evaluate the literature on sodium pentosan polysulfate (NaPPS) and calcium pentosan polysulfate (CaPPS), with respect to the pathobiology of OA to ascertain whether these agents should be classified as SMOADs.

METHODS

Published studies on NaPPS and CaPPS were selected on the basis of their relevance to the known pathobiology of OA, which also was reviewed.

RESULTS

Both NaPPS and CaPPS exhibit a wide range of pharmacological activities. Of significance was the ability of these agents to support chondrocyte anabolic activities and attenuate catabolic events responsible for loss of components of the cartilage extracellular matrix in OA joints. Although some of the anti-catabolic activities may be mediated through direct enzyme inhibition, NaPPS and CaPPS also have been shown to enter chondrocytes and bind to promoter proteins and alter gene expression of matrix metalloproteinases and possibly other mediators. In rat models of arthritis, NaPPS and CaPPS reduced joint swelling and inflammatory mediator levels in pouch fluids. Moreover, synoviocyte biosynthesis of high-molecular-weight hyaluronan, which is diminished in OA, was normalized when these cells were incubated with NaPPS and CaPPS or after intraarticular injection of NaPPS into arthritic joints. In rabbit, canine, and ovine models of OA, NaPPS and CaPPS preserved cartilage integrity, proteoglycan synthesis, and reduced matrix metalloproteinase activity. NaPPS and CaPPS stimulated the release of tissue plasminogen activator (t-PA), superoxide dismutase, and lipases from vascular endothelium while concomitantly decreasing plasma levels of the endogenous plasminogen activator inhibitor PAI-1. The net thrombolytic and lipolytic effects exhibited by NaPPS and CaPPS may serve to improve blood flow through subchondral capillaries of OA joints and improve bone cell nutrition. In geriatric OA dogs, NaPPS and CaPPS reduced symptoms, as well as normalized their thrombolytic status, threshold for platelet activation, and plasma triglyceride levels. These hematologic parameters were shown to be abnormal in OA animals before drug treatment. Similar outcomes were observed in OA patients when CaPPS or NaPPS were given orally or parenterally in both open and double-blind trials.

CONCLUSIONS

The data presented in this review support the contention that NaPPS and CaPPS should be classified as SMOADs. However, additional long-term clinical studies employing methods of assessing joint structural changes will be needed to confirm this view.

Glycosaminoglycans and other sulphated polysaccharides in calculogenesis of urinary stones

Naturally occurring glycosaminoglycans (GAGs) and other, semisynthetic, sulphated polysaccharides are thought to play an important role in urolithiasis. Processes involved in urinary stone formation are crystallization and crystal retention. Oxalate transport and renal tubular cell injury are determining factors in these processes. In this article experimental results concerning the possible mechanisms of action of GAGs and other sulphated polysaccharides are reviewed. GAGs are inhibitors of crystal growth and agglomeration and possibly also of nucleation. They can prevent crystal adherence, correct an abnormal oxalate flux and prevent renal tubular cell damage.

The production of antibodies to pentosanpolysulfate (ELMIRON, SP-54)

Pentosanpolysulfate (PPS) represents the product obtained after sulfation of xylan and is composed of beta 1----4-D-xylopyranose residues sulfated at C2 and C3. Studies have shown that this compound can often be effective in relieving the symptoms of interstitial cystitis (IC). In order to elucidate the mode of action of PPS in IC, a sensitive and reliable assay was needed. To this end we prepared an immunogenic form of PPS by coupling it to methylated bovine serum albumin (MBSA). This complex was used to immunize NZW rabbits (1 mg, IM). Four of five animals responded with anti-PPS antibodies, three of which had high titer (greater than 1/2000) as measured by an enzyme-linked immunosorbent assay (ELISA). All sera were routinely absorbed with an MBSA-Sepharose immunoadsorbent to remove anti-MBSA antibodies. ELISA inhibition tests were used to determine the sensitivity and specificity of the sera. At least 50 ng/ml of PPS could be routinely detected by this assay. A number of naturally occurring proteoglycans, polysaccharides, monosaccharides and disaccharides were examined for reactivity with the antibodies but only heparin was an effective inhibitor. Absorption with heparin immunoadsorbents reduced, but did not eliminate, the ability of heparin to inhibit anti-PPS binding. This activity could be destroyed by treatment with heparinase without affecting PPS inhibition. Normal urine did not affect the ELISA or ELISA inhibition tests and thus allowed the determination of PPS levels in IC patient urines. Initial analysis of seven IC patients receiving oral PPS revealed urine concentration of 0.8-16.0 micrograms/ml. No inhibition could be detected in pre-treatment urine samples.