Pentosan polysulfate inhibits atherosclerosis in Watanabe heritable hyperlipidemic rabbits: differential modulation of metalloproteinase-2 and -9

Pentosan Polysulfate Affords Pleotropic Protection to Multiple Cells and Tissues

Pentosan polysulfate (PPS), a small semi-synthetic highly sulfated heparan sulfate (HS)-like molecule, shares many of the interactive properties of HS. The aim of this review was to outline the potential of PPS as an interventional therapeutic protective agent in physiological processes affecting pathological tissues. PPS is a multifunctional molecule with diverse therapeutic actions against many disease processes. PPS has been used for decades in the treatment of interstitial cystitis and painful bowel disease, it has tissue-protective properties as a protease inhibitor in cartilage, tendon and IVD, and it has been used as a cell-directive component in bioscaffolds in tissue engineering applications. PPS regulates complement activation, coagulation, fibrinolysis and thrombocytopenia, and it promotes the synthesis of hyaluronan. Nerve growth factor production in osteocytes is inhibited by PPS, reducing bone pain in osteoarthritis and rheumatoid arthritis (OA/RA). PPS also removes fatty compounds from lipid-engorged subchondral blood vessels in OA/RA cartilage, reducing joint pain. PPS regulates cytokine and inflammatory mediator production and is also an anti-tumor agent that promotes the proliferation and differentiation of mesenchymal stem cells and the development of progenitor cell lineages that have proven to be useful in strategies designed to effect repair of the degenerate intervertebral disc (IVD) and OA cartilage. PPS stimulates proteoglycan synthesis by chondrocytes in the presence or absence of interleukin (IL)-1, and stimulates hyaluronan production by synoviocytes. PPS is thus a multifunctional tissue-protective molecule of potential therapeutic application for a diverse range of disease processes.

Anti-inflammatory actions of Pentosan polysulfate sodium in a mouse model of influenza virus A/PR8/34-induced pulmonary inflammation

Introduction

There is an unmet medical need for effective anti-inflammatory agents for the treatment of acute and post-acute lung inflammation caused by respiratory viruses. The semi-synthetic polysaccharide, Pentosan polysulfate sodium (PPS), an inhibitor of NF-kB activation, was investigated for its systemic and local anti-inflammatory effects in a mouse model of influenza virus A/PR8/1934 (PR8 strain) mediated infection.

Methods

Immunocompetent C57BL/6J mice were infected intranasally with a sublethal dose of PR8 and treated subcutaneously with 3 or 6 mg/kg PPS or vehicle. Disease was monitored and tissues were collected at the acute (8 days post-infection; dpi) or post-acute (21 dpi) phase of disease to assess the effect of PPS on PR8-induced pathology.

Results

In the acute phase of PR8 infection, PPS treatment was associated with a reduction in weight loss and improvement in oxygen saturation when compared to vehicle-treated mice. Associated with these clinical improvements, PPS treatment showed a significant retention in the numbers of protective SiglecF+ resident alveolar macrophages, despite uneventful changes in pulmonary leukocyte infiltrates assessed by flow cytometry. PPS treatment in PR8- infected mice showed significant reductions systemically but not locally of the inflammatory molecules, IL-6, IFN-g, TNF-a, IL-12p70 and CCL2. In the post-acute phase of infection, PPS demonstrated a reduction in the pulmonary fibrotic biomarkers, sICAM-1 and complement factor C5b9.

Discussion

The systemic and local anti-inflammatory actions of PPS may regulate acute and post-acute pulmonary inflammation and tissue remodeling mediated by PR8 infection, which warrants further investigation.

Pentosan Polysulfate Sodium augments the therapeutic effect of 5-Aminosalicylic Acid in DSS colitis model; the role of IL-35 expression

Ulcerative colitis (UC) primarily affects the mucosa of the distal colon. Dysregulated immune response in genetically-prone persons is claimed to be responsible for chronic intestinal inflammation. This study aimed to explore the efficacy and the hematological effects of pentosan polysulfate sodium (PPS) in a dextran sulfate sodium (DSS)-induced colitis model. Forty C57BL/6 female mice were equally divided into five groups: control group, DSS-colitis group, DSS-colitis treated with 5-aminosalicylic acid, DSS-colitis treated with PPS, and DSS-colitis treated with both drugs. Disease activity index (DAI) and colon length were calculated. Colonic IL-6 and IL-35 levels were assayed by ELISA. IL-35 gene expression was evaluated by qRT-PCR. Colon tissue samples were examined by H&E stain and immunohistochemistry (IHC) of Ki67. The colitis group subjected to combined treatment showed the best outcome with significant improvement of DAI and increased colon length. Colonic IL-6 was significantly lower in both PPS- and combination-treated groups accompanied by a significantly higher IL-35 level and its EBI3 subunit mRNA expression. However, the PPS-treated colitis group showed higher gene expression of IL-35 EBI3 subunit by 1.5-fold compared with the combined group. The colon mucosa and crypts were significantly preserved in mice treated with both drugs with the best Ki67 positive cell density. PPS is a safe and promising drug in the treatment of UC as it exerted the best positive effect on the anti-inflammatory IL-35 level and gene expression. However, superior improvement of DAI was seen when PPS was added to ASA with a greater mucosal proliferation and repair.

Pentosan Polysulfate Demonstrates Anti-human T-Cell Leukemia Virus Type 1 Activities In Vitro and In Vivo

Human T-cell leukemia virus type 1 (HTLV-1) infection causes T-cell leukemia and inflammatory diseases, most notably including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The underlying mechanism for the pathogenesis of HAM/TSP remains unclear. According to a recent clinical trial, a humanized antibody that targets CCR4⁺ cells ameliorates inflammation by reducing the number of infected cells in the central nervous system; this result suggests that the transmigration of HTLV-1-infected cells plays a crucial role in HAM/TSP. Partly due to the blood-brain barrier, current treatments for HAM/TSP are mostly palliative. Pentosan polysulfate (PPS), a semisynthetic glycosaminoglycan, has recently been used to treat HAM/TSP and was found to alleviate the symptoms. In this study, we investigated the effect of PPS on HTLV-1-infected cells and provide evidence for its efficacy in HAM/TSP. PPS was cytotoxic to certain HTLV-1-infected cells and significantly suppressed HTLV-1 virion production. PPS also efficiently inhibited HTLV-1 cell-cell transmission in T cells. In addition, PPS blocked HTLV-1 infection of primary endothelial cells (human umbilical vascular endothelial cells) and suppressed the subsequent induction of proinflammatory cytokine expression. Furthermore, PPS was found to inhibit the adhesion and transmigration of HTLV-1-infected cells. We also confirmed the anti-HTLV-1 effect of PPS in vivo using two mouse models. PPS blocked HTLV-1 infection in a mouse model with peripheral blood mononuclear cell (PBMC)-humanized NOD-scid IL2Rgamma^null (huPBMC NSG) mice. PPS was also found to suppress the development of dermatitis and lung damage in HTLV-1 bZIP factor (HBZ)-transgenic (HBZ-Tg) mice, an HTLV-1 transgenic mouse model in which the mice develop systemic inflammation.IMPORTANCE HTLV-1 is the first human retrovirus to have been identified and is endemic in certain areas worldwide. HTLV-1 infection leads to the development of an inflammatory disease called HAM/TSP, a myelopathy characterized by slowly progressive spastic paraparesis. There have been no effective therapeutics available for HAM/TSP, but recently, a semisynthetic glycosaminoglycan, named pentosan polysulfate (PPS), has been found to alleviate the symptoms of HAM/TSP. Here we conducted a comprehensive study on the effect of PPS both in vitro and in vivo PPS demonstrated anti-HTLV-1 potential in infected cell lines, as shown by its suppressive effects on HTLV-1 replication and transmission and on the transmigration of infected T cells. Moreover, results obtained from two HTLV-1 mouse models demonstrate that PPS inhibits HTLV-1 infection and inflammation development in vivo Our work offers insights into the treatment of HAM/TSP by PPS and also suggests its possible use for treating other HTLV-1-induced inflammatory diseases.

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.

Systems Based Study of the Therapeutic Potential of Small Charged Molecules for the Inhibition of IL-1 Mediated Cartilage Degradation

Inflammatory cytokines are key drivers of cartilage degradation in post-traumatic osteoarthritis. Cartilage degradation mediated by these inflammatory cytokines has been extensively investigated using in vitro experimental systems. Based on one such study, we have developed a computational model to quantitatively assess the impact of charged small molecules intended to inhibit IL-1 mediated cartilage degradation. We primarily focus on the simplest possible computational model of small molecular interaction with the IL-1 system-direct binding of the small molecule to the active site on the IL-1 molecule itself. We first use the model to explore the uptake and release kinetics of the small molecule inhibitor by cartilage tissue. Our results show that negatively charged small molecules are excluded from the negatively charged cartilage tissue and have uptake kinetics in the order of hours. In contrast, the positively charged small molecules are drawn into the cartilage with uptake and release timescales ranging from hours to days. Using our calibrated computational model, we subsequently explore the effect of small molecule charge and binding constant on the rate of cartilage degradation. The results from this analysis indicate that the small molecules are most effective in inhibiting cartilage degradation if they are either positively charged and/or bind strongly to IL-1α, or both. Furthermore, our results showed that the cartilage structural homeostasis can be restored by the small molecule if administered within six days following initial tissue exposure to IL-1α. We finally extended the scope of the computational model by simulating the competitive inhibition of cartilage degradation by the small molecule. Results from this model show that small molecules are more efficient in inhibiting cartilage degradation by binding directly to IL-1α rather than binding to IL-1α receptors. The results from this study can be used as a template for the design and development of more pharmacologically effective osteoarthritis drugs, and to investigate possible therapeutic options.

Proteinuria and lipoprotein lipase activity in Miniature Schnauzer dogs with and without hypertriglyceridemia

Spontaneous hyperlipidemia in rats causes glomerular disease. Idiopathic hypertriglyceridemia (HTG) is prevalent in Miniature Schnauzers, but its relationship with proteinuria is unknown. Decreased activity of major lipid metabolism enzymes, lipoprotein lipase (LPL) and hepatic lipase (HL), may play a role in the cyclic relationship between hyperlipidemia and proteinuria. These enzymes have also not been previously investigated in Miniature Schnauzers. The aims of this study were to determine the relationship between HTG and proteinuria in Miniature Schnauzers and to measure LPL and HL activities in a subset of dogs. Fifty-seven Miniature Schnauzers were recruited (34 with and 23 without HTG). Fasting serum triglyceride concentrations and urine protein-to-creatinine ratios (UPC) were measured in all dogs, and LPL and HL activities were determined in 17 dogs (8 with and 9 without HTG). There was a strong positive correlation between triglyceride concentration and UPC (r = 0.77-0.83, P < 0.001). Proteinuria (UPC ≥ 0.5) was present in 60% of dogs with HTG and absent from all dogs without HTG (P < 0.001). Proteinuric dogs were not azotemic or hypoalbuminemic. Dogs with HTG had a 65% reduction in LPL activity relative to dogs without HTG (P < 0.001); HL activity did not differ. Proteinuria occurs with HTG in Miniature Schnauzers and could be due to lipid-induced glomerular injury. Reduced LPL activity may contribute to the severity of HTG, but further assay validation is required.

Pentosan polysulfate preserves renal microvascular P2X1 receptor reactivity and autoregulatory behavior in DOCA-salt hypertensive rats

Inflammation contributes to ANG II-associated impairment of renal autoregulation and microvascular P2X1 receptor signaling, but its role in renal autoregulation in mineralocorticoid-induced hypertension is unknown. Autoregulatory behavior was assessed using the blood-perfused juxtamedullary nephron preparation. Hypertension was induced in uninephrectomized control rats (UNx) by subcutaneous implantation of a DOCA pellet plus administration of 1% NaCl in the drinking water (DOCA-salt) for 3 wk. DOCA-salt rats developed hypertension that was unaltered by anti-inflammatory treatment with pentosan polysulfate (DOCA-salt+PPS) but was suppressed with "triple therapy" (hydrochlorothiazide, hydralazine, and reserpine; DOCA-salt+TTx). Baseline arteriolar diameters were similar across all groups. UNx rats exhibited pressure-dependent vasoconstriction with diameters declining to 69 ± 2% of control at 170 mmHg, indicating intact autoregulation. DOCA-salt treatment significantly blunted this pressure-mediated vasoconstriction. Diameters remained between 91 ± 4 and 98 ± 3% of control over 65-170 mmHg, indicating impaired autoregulation. In contrast, pressure-mediated vasoconstriction was preserved in DOCA-salt+PPS and DOCA-salt+TTx rats, reaching 77 ± 7 and 75 ± 3% of control at 170 mmHg, respectively. ATP is required for autoregulation via P2X1 receptor activation. ATP- and β,γ-methylene ATP (P2X1 receptor agonist)-mediated vasoconstriction were markedly attenuated in DOCA-salt rats compared with UNx (P < 0.05), but significantly improved by PPS or TTx (P < 0.05 vs. DOCA-salt) treatment. Arteriolar responses to adenosine and UTP (P2Y2 receptor agonist) were unaffected by DOCA-salt treatment. PPS and TTx significantly reduced MCP-1 and protein excretion in DOCA-salt rats. These results support the hypothesis that hypertension triggers inflammatory cascades but anti-inflammatory treatment preserves renal autoregulation in DOCA-salt rats, most likely by normalizing renal microvascular reactivity to P2X1 receptor activation.

Immunomodulatory activity of orphan drug Elmiron® in female B6C3F1/N mice

Interstitial cystitis (IC) is a chronic disorder characterized by bladder discomfort and urinary urgency in the absence of identifiable infection. Despite the expanding use in IC treatment and other chronic conditions, the effects of Elmiron® treatment on immune system remain unknown. Therefore, female B6C3F1/N mice were orally administered Elmiron® daily for 28-days at doses of 63, 125, 250, 500 or 1000mg/kg to evaluate its immunomodulatory effects. Mice treated with Elmiron® had a significant increase in absolute numbers of splenic macrophages (63, 500 and 1000mg/kg) and natural killer (NK) cells (250 and 1000mg/kg). Elmiron® treatment did not affect the humoral immune response or T cell proliferative response. However, innate immune responses such as phagocytosis by liver macrophages (1000mg/kg) and NK cell activity were enhanced (500 and 1000mg/kg). Further analysis using a disease resistance model showed that Elmiron®-treated mice demonstrated significantly increased anti-tumor activity against B16F10 melanoma cells at the 500 and 1000mg/kg doses. Collectively, we conclude that Elmiron® administration stimulates the immune system, increasing numbers of specific cell populations and enhancing macrophage phagocytosis and NK cell activity in female B6C3F1/N mice. This augmentation may have largely contributed to the reduced number of B16F10 melanoma tumors.

Pentosan polysulfate: a novel therapy for the mucopolysaccharidoses

Background

Pentosan polysulfate (PPS) is an FDA-approved, oral medication with anti-inflammatory and pro-chondrogenic properties. We have previously shown that animal models of the mucopolysaccharidoses (MPS) exhibit significant inflammatory disease, contributing to cartilage degeneration. Enzyme replacement therapy (ERT) only partly reduced inflammation, and anti-TNF-alpha antibody therapy significantly enhanced clinical and pathological outcomes. Here we describe the use of PPS for the treatment of MPS type VI rats.

Methodology/Principal Findings

Treatment began during prenatal development and at 1 and 6 months of age. All animals were treated until they were 9 months old. Significant reductions in the serum and tissue levels of several inflammatory markers (e.g., TNF-alpha, MIP-1alpha and RANTES/CCL5) were observed, as was reduced expression of inflammatory markers in cultured articular chondrocytes. ADAMTS-5/aggrecanase-2 levels also were reduced in chondrocytes, consistent with an elevation of serum tissue inhibitor of metalloproteinase 1. Marked improvements in motility and grooming behavior occurred, along with a reduction in eye and nasal secretions and a lessening of the tracheal deformities. MicroCT and radiographic analyses further revealed that the treated MPS skulls were longer and thinner, and that the teeth malocclusions, misalignments and mineral densities were improved. MicroCT analysis of the femurs and vertebrae revealed improvements in trabecular bone mineral densities, number and spacing in a subset of treated MPS animals. Biomechanical assessments of PPS-treated spines showed partially restored torsional behaviors, suggesting increased spinal stability. No improvements were observed in cortical bone or femur length. The positive changes in the PPS-treated MPS VI rats occurred despite glycosaminoglycan accumulation in their tissues.

Conclusions

Based on these findings we conclude that PPS could be a simple and effective therapy for MPS that might provide significant clinical benefits alone and in combination with other therapies.