Sulodexide suppresses inflammation in human endothelial cells and prevents glucose cytotoxicity

Sulodexide Inhibits Arterial Contraction via the Endothelium-Dependent Nitric Oxide Pathway

Background/Objectives: Sulodexide (SDX) is a drug known for restoring the glycocalyx, thereby offering endothelial protection and regulating permeability. Additionally, it has antithrombotic and anti-inflammatory properties and has shown arterial vasodilatory effects. Endothelial cells play a crucial role in maintaining homeostasis, with their dysfunction being a key contributor to loss in vasodilatory response, especially in arterial pathologies. The aim of this study was to investigate the effects of SDX on stimulated vascular tonus in human arterial samples and to assess the function of the endothelial layer as a source of nitric oxide (NO). Methods: A total of 16 internal mammary artery remnants from coronary artery bypass graft surgeries were dissected into endothelium-intact and endothelium-denuded groups (n = 8 each). The arterial rings were equilibrated under tension, with their basal tonus recorded before and after phenylephrine stimulation. SDX's impact on arterial contraction was assessed through cumulative dose-response curves. NO synthase inhibitor (Nω-nitro-L-arginine methyl ester) was used to assess SDX's vasodilatory effect over the NO pathway. Results: SDX application resulted in concentration-dependent vasorelaxation in both endothelium-intact and endothelium-denuded groups at certain doses. However, the inhibitory effect of SDX was more pronounced in endothelium-intact rings at higher doses compared to endothelium-denuded rings (p < 0.05). Similar inhibition of contraction curves was achieved for both endothelium-intact and endothelium-denuded rings after L-NAME pre-incubation, suggesting a necessity for NO-related endothelial pathways. Conclusions: SDX exerts a concentration-dependent inhibition on arterial contraction, emphasizing the critical role of an intact endothelium and NO-mediated pathways in this process. This underscores SDX's potential in treating endothelial dysfunction-related pathologies.

Sulodexide attenuates liver fibrosis in mice by restoration of differentiated liver sinusoidal endothelial cell

Sulodexide is a heparinoid compound with wide-ranging pharmacological activities. However, the effect of sulodexide on liver fibrogenesis has not been reported. In this study, we aim to evaluate the therapeutic potential of sulodexide in mouse model of liver fibrosis and explore the underlying antifibrotic mechanisms. We found that sulodexide treatment significantly attenuated thioacetamide (TAA) and 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-induced liver fibrosis in mice. Transcriptome analysis revealed that sulodexide treatment downregulated fibrosis-related genes and liver sinusoidal endothelial cells (LSECs) capillarization-associated genes in fibrotic livers. Immunohistochemistry confirmed that the increased expression of LSEC capillarization-related genes (CD34, CD31 and Laminin) in liver fibrotic tissues was reduced by sulodexide treatment. Scanning electron microscopy showed that LSECs fenestrations were preserved upon sulodexide treatment. Quantitative real-time PCR and immunofluorescence demonstrated that the expression of mesenchymal markers was downregulated by sulodexide administration, suggesting sulodexide inhibited endothelial-mesenchymal transition of LSECs during liver fibrosis. Furthermore, sulodexide administration protected primary LSECs from endothelial dysfunction in vitro. In conclusion, sulodexide attenuated liver fibrosis in mice by restoration of differentiated LSECs, indicating that sulodexide treatment may present as a potential therapy for patients with liver fibrosis.

Sulodexide Increases Glutathione Synthesis and Causes Pro-Reducing Shift in Glutathione-Redox State in HUVECs Exposed to Oxygen–Glucose Deprivation: Implication for Protection of Endothelium against Ischemic Injury

Sulodexide (SDX), a purified glycosaminoglycan mixture used to treat vascular diseases, has been reported to exert endothelial protective effects against ischemic injury. However, the mechanisms underlying these effects remain to be fully elucidated. The emerging evidence indicated that a relatively high intracellular concentration of reduced glutathione (GSH) and a maintenance of the redox environment participate in the endothelial cell survival during ischemia. Therefore, the aim of the present study was to examine the hypothesis that SDX alleviates oxygen–glucose deprivation (OGD)-induced human umbilical endothelial cells’ (HUVECs) injury, which serves as the in vitro model of ischemia, by affecting the redox state of the GSH: glutathione disulfide (GSSG) pool. The cellular GSH, GSSG and total glutathione (tGSH) concentrations were measured by colorimetric method and the redox potential (ΔEh) of the GSSG/2GSH couple was calculated, using the Nernst equation. Furthermore, the levels of the glutamate–cysteine ligase catalytic subunit (GCLc) and the glutathione synthetase (GSS) proteins, a key enzyme for de novo GSH synthesis, were determined using enzyme-linked immunoassay (ELISA). We demonstrated that the SDX treatment in OGD conditions significantly elevated the intracellular GSH, enhanced the GSH:GSSG ratio, shifting the redox potential to a more pro-reducing status. Furthermore, SDX increased the levels of both GCLc and GSS. The results show that SDX protects the human endothelial cells against ischemic stress by affecting the GSH levels and cellular redox state. These changes suggest that the reduction in the ischemia-induced vascular endothelial cell injury through repressing apoptosis and oxidative stress associated with SDX treatment may be due to an increase in GSH synthesis and modulation of the GSH redox system.

The microvascular endothelial glycocalyx: An additional piece of the puzzle in veterinary medicine

The endothelial glycocalyx (eGlx) is a critically important structure lining the luminal surface of endothelial cells. There is increasing evidence, in human patients and animal models, for its crucial role in the maintenance of health. Moreover, its damage is associated with the pathogenesis of multiple disease states. This review provides readers with an overview of the eGlx; summarising its structure, essential functions, and evidence for its role in disease. We highlight the lack of studies regarding the eGlx in cats and dogs, particularly in naturally occurring diseases. Importantly, we discuss techniques to aid its study, which can be applied to veterinary species. Finally, we present targeted therapies aimed at preserving, and in some cases, restoring damaged eGlx.

Hydrogen Sulfide Is a Novel Protector of the Retinal Glycocalyx and Endothelial Permeability Barrier

Significantly reduced levels of the anti-inflammatory gaseous transmitter hydrogen sulfide (H₂S) are observed in diabetic patients and correlate with microvascular dysfunction. H₂S may protect the microvasculature by preventing loss of the endothelial glycocalyx. We tested the hypothesis that H₂S could prevent or treat retinal microvascular endothelial dysfunction in diabetes. Bovine retinal endothelial cells (BRECs) were exposed to normal (NG, 5.5 mmol/L) or high glucose (HG, 25 mmol/L) ± the slow-release H₂S donor NaGYY4137 in vitro. Glycocalyx coverage (stained with WGA-FITC) and calcein-labeled monocyte adherence were measured. In vivo, fundus fluorescein angiography (FFA) was performed in normal and streptozotocin-induced (STZ) diabetic rats. Animals received intraocular injection of NaGYY4137 (1 μM) or the mitochondrial-targeted H₂S donor AP39 (100 nM) simultaneously with STZ (prevention) or on day 6 after STZ (treatment), and the ratio of interstitial to vascular fluorescence was used to estimate apparent permeability. NaGYY4137 prevented HG-induced loss of BREC glycocalyx, increased monocyte binding to BRECs (p ≤ 0.001), and increased overall glycocalyx coverage (p ≤ 0.001). In rats, the STZ-induced increase in apparent retinal vascular permeability (p ≤ 0.01) was significantly prevented by pre-treatment with NaGYY4137 and AP39 (p < 0.05) and stabilized by their post-STZ administration. NaGYY4137 also reduced the number of acellular capillaries (collagen IV + /IB4-) in the diabetic retina in both groups (p ≤ 0.05). We conclude that NaGYY4137 and AP39 protected the retinal glycocalyx and endothelial permeability barrier from diabetes-associated loss of integrity and reduced the progression of diabetic retinopathy (DR). Hydrogen sulfide donors that target the glycocalyx may therefore be a therapeutic candidate for DR.

Sulodexide reduces glucose induced senescence in human retinal endothelial cells

Chronic exposure of retinal endothelium cells to hyperglycemia is the leading cause of diabetic retinopathy. We evaluated the effect of high glucose concentration on senescence in human retinal endothelial cells (HREC) and modulation of that effect by Sulodexide. Experiments were performed on HREC undergoing in vitro replicative senescence in standard medium or medium supplemented with glucose 20 mmol/L (GLU) or mannitol 20 mnol/L (MAN). Effect of Sulodexide 0.5 LRU/mL (SUL) on the process of HREC senescence was studied. Glucose 20 mmol/L accelerates senescence of HREC: population doubling time (+ 58%, p < 0.001) β-galactosidase activity (+ 60%, p < 0.002) intracellular oxidative stress (+ 65%, p < 0.01), expression of p53 gene (+ 118%, p < 0.001). Senescent HREC had also reduced transendothelial electrical resistance (TEER) (- 30%, p < 0.001). Mannitol 20 mmol/L used in the same scenario as glucose did not induce HREC senescence. In HREC exposed to GLU and SUL, the senescent changes were smaller. HREC, which became senescent in the presence of GLU, demonstrated higher expression of genes regulating the synthesis of Il6 and VEGF-A, which was reflected by increased secretion of these cytokines (IL6 + 125%, p < 0.001 vs control and VEGF-A + 124% p < 0.001 vs control). These effects were smaller in the presence of SUL, and additionally, an increase of TEER in the senescent HREC was observed. Chronic exposure of HREC to high glucose concentration in medium accelerates their senescence, and that process is reduced when the cells are simultaneously exposed to Sulodexide. Additionally, Sulodexide decreases the secretion of IL6 and VEGF-A from senescent HREC and increases their TEER.

Mechanisms of Lower Extremity Vein Dysfunction in Chronic Venous Disease and Implications in Management of Varicose Veins

Chronic venous disease (CVD) is a common venous disorder of the lower extremities. CVD can be manifested as varicose veins (VVs), with dilated and tortuous veins, dysfunctional valves and venous reflux. If not adequately treated, VVs could progress to chronic venous insufficiency (CVI) and lead to venous leg ulcer (VLU). Predisposing familial and genetic factors have been implicated in CVD. Additional environmental, behavioral and dietary factors including sedentary lifestyle and obesity may also contribute to CVD. Alterations in the mRNA expression, protein levels and proteolytic activity of matrix metalloproteinases (MMPs) have been detected in VVs and VLU. MMP expression/activity can be modulated by venous hydrostatic pressure, hypoxia, tissue metabolites, and inflammation. MMPs in turn increase proteolysis of different protein substrates in the extracellular matrix particularly collagen and elastin, leading to weakening of the vein wall. MMPs could also promote venous dilation by increasing the release of endothelium-derived vasodilators and activating potassium channels, leading to smooth muscle hyperpolarization and relaxation. Depending on VVs severity, management usually includes compression stockings, sclerotherapy and surgical removal. Venotonics have also been promoted to decrease the progression of VVs. Sulodexide has also shown benefits in VLU and CVI, and recent data suggest that it could improve venous smooth muscle contraction. Other lines of treatment including induction of endogenous tissue inhibitors of metalloproteinases (TIMPs) and administration of exogenous synthetic inhibitors of MMPs are being explored, and could provide alternative strategies in the treatment of CVD.

Diabetic nephropathy: A twisted thread to unravel

Diabetic nephropathy (DN), a persistent microvascular problem of diabetes mellitus is described as an elevated level of albumin excretion in urine and impaired renal activity. The morbidity and mortality of type-1 diabetics and type-2 diabetics due to end stage renal disease is also a result of the increased prevalence of DN. DN typically occurs as a consequence of an association among metabolic and hemodynamic variables, activating specific pathways leading to renal injury. According to current interventions, intensive glucose regulation decreases the threat of DN incidence and growth, and also suppressing the renin-angiotensin system (RAS) is a significant goal for hemodynamic and metabolism-related deformities in DN. However, the pathogenesis of DN is multifactorial so novel approaches other than glucose and blood pressure control are required for treatment. This review briefly summarizes the reported pathogenesis of DN, current interventions for its treatment, and possible novel interventions to unweave the thread of DN.

In Vivo and In Vitro Assays Evaluating the Biological Activity of Taurine, Glucose and Energetic Beverages

Taurine is one of the main ingredients used in energy drinks which are highly consumed in adolescents for their sugary taste and stimulating effect. With energy drinks becoming a worldwide phenomenon, the biological effects of these beverages must be evaluated in order to fully comprehend the potential impact of these products on the health due to the fact nutrition is closely related to science since the population consumes food to prevent certain diseases. Therefore, the aim of this study was to evaluate the biological effects of taurine, glucose, classic Red Bull® and sugar-free Red Bull® in order to check the food safety and the nutraceutical potential of these compounds, characterising different endpoints: (i) Toxicology, antitoxicology, genotoxicology and life expectancy assays were performed in the Drosophila melanogaster model organism; (ii) The in vitro chemopreventive activity of testing compounds was determined by assessing their cytotoxicity, the proapoptotic DNA-damage capability to induce internucleosomal fragmentation, the strand breaks activity and the modulator role on the methylation status of genomic repetitive sequences of HL-60 promyelocytic cells. Whereas none tested compounds showed toxic or genotoxic effect, all tested compounds exerted antitoxic and antigenotoxic activity in Drosophila. Glucose, classic Red Bull® and sugar-free Red Bull® were cytotoxic in HL-60 cell line. Classic Red Bull® induced DNA internucleosomal fragmentation although none of them exhibited DNA damage on human leukaemia cells. In conclusion, the tested compounds are safe on Drosophila melanogaster and classic Red Bull® could overall possess nutraceutical potential in the in vivo and in vitro model used in this study. Besides, taurine could holistically be one of the bioactive compounds responsible for the biological activity of classic Red Bull®.

Sulodexide in the Treatment of Patients with Early Stages of COVID-19: A Randomized Controlled Trial

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may induce several vascular endothelial-dependent systemic complications, and sulodexide has pleiotropic actions on the vascular endothelium, which may prove beneficial. We aimed to assess the effect of sulodexide when used within 3 days of coronavirus disease 2019 (COVID-19) clinical onset. We conducted a randomized placebo-controlled outpatient trial. To be included, patients must have been at high risk for severe clinical progression. Participants received sulodexide (oral 1,000 LRU/d) or placebo for 21 days. The primary endpoint was the need for hospital care. Also assessed were patients' need for supplemental oxygen as well as D-dimer and C-reactive protein (CRP) levels, thromboembolic events, major bleeding, and mortality. A total of 243 patients were included in the per-protocol analysis from June 5 to August 30, 2020. Of these, 124 received sulodexide and 119 received a placebo. Only 17.7% of the patients in the sulodexide group required hospitalization, compared with 29.4% in the placebo group (p = 0.03). This benefit persisted in the intention-to-treat analysis (15% in sulodexide group vs. 24% with placebo [p = 0.04]). With sulodexide, fewer patients required supplemental oxygen (30 vs. 42% [p = 0.05]). After 2 weeks, fewer patients had D-dimer levels >500 ng/dL (22 vs. 47% [p < 0.01]), and patients also had lower mean CRP levels (12.5 vs. 17.8 mg/dL [p < 0.01]). There were no between-group differences in thromboembolic events, major bleeding, or mortality. Treatment of COVID-19 patients with sulodexide, when provided within 3 days of clinical onset, improved their clinical outcomes. Although the results should be confirmed, sulodexide could be valuable in an outpatient setting.

Rationale for the Role of Heparin and Related GAG Antithrombotics in COVID-19 Infection

The SARS-CoV-2 pandemic has focused attention on prevention, restriction and treatment methods that are acceptable worldwide. This means that they should be simple and inexpensive. This review examines the possible role of glycosaminoglycan (GAG) antithrombotics in the treatment of COVID-19. The pathophysiology of this disease reveals a complex interplay between the hemostatic and immune systems that can be readily disrupted by SARS-CoV-2. Some of the GAG antithrombotics also possess immune-modulatory actions and since they are relatively inexpensive they could play an important role in the management of COVID-19 and its complications.

[Glycocalyx as a determining factor in development of endothelial venous dysfunction and possibilities of correction thereof]

Modern vascular surgery has the data on a substantial role of the endothelium in pathogenesis of vascular diseases. Endothelial dysfunction is associated with a wide range of pathological processes including those in chronic diseases of lower-limb veins. The discovery of the endothelial glycocalyx made it possible to evaluate its role in the development of endothelial dysfunction as a trigger mechanism in impairment of venous blood flow. The understanding of the unifying role of endothelial dysfunction in pathology in various fields of medicine provides a possibility of predicting the development of serious socially significant diseases such as cardiovascular diseases, diabetes mellitus, obstetrical complications, and to correct the conditions associated therewith. The present study was aimed at carrying out a systematic literature review, thus making it possible to evaluate the role of the endothelial glycocalyx in the development of endothelial dysfunction, as well as to determine therapy with sulodexide capable of decreasing the probability of the onset of endothelial dysfunction at the expense of an anti-inflammatory, antithrombotic, and angioprotective effect on the endothelial wall.

Comparative Anticoagulant and Thrombin Generation Inhibitory Profile of Heparin, Sulodexide and Its Components

INTRODUCTION

Sulodexide represents a mixture of fast-moving heparin (FMH) and dermatan sulfate (DS) and has been used for the management of venous diseases such as DVT and related disorders. The purpose of this study is to compare sulodexide and its components with unfractionated heparin (UFH) to determine its suitability for the indications in which UFH is used.

MATERIALS AND METHOD

Active pharmaceutical ingredients (API) versions of sulodexide, FMH and DS were obtained from Alfasigma. API versions of UFH were obtained from Medefil Inc. Normal human citrated plasma was obtained from blood bank of the Loyola University Medical Center. Each of the individual agents were supplemented in plasma at a graded concentration of 0.0-10 µg/mL. Clotting assays (PiCT, aPTT, PT and TT), anti-Xa and anti-IIa and thrombin generation studies were carried out. Results were compiled as mean ± SD of 3 individual determination.

RESULT

In the clot based (PiCT, aPTT and TT), anti-Xa and IIa assays, both the UFH and FMH produced stronger activities in these assays followed by sulodexide. DS did not show any anticoagulant activity. In the thrombin generation assay, FMH and UFH produced comparable inhibition of thrombin generation as measured by various parameters. Sulodexide was slightly weaker in this assay, whereas DS produced relatively weaker effects.

CONCLUSION

In comparison to sulodexide, both UFH and FMH exhibit comparable anticoagulant activity despite differences in their molecular weight. These results suggest that sulodexide can be developed as a parenteral anticoagulant for indications in which UFH is used.

Sulodexide promotes arterial relaxation via endothelium-dependent nitric oxide-mediated pathway

Sulodexide (SDX) is a highly purified glycosaminoglycan with antithrombotic and profibrinolytic properties and reported benefits in thrombotic and atherosclerotic vascular disorders. However, the effects of SDX on vascular function are unclear. We tested whether SDX affects vascular relaxation and examined the potential underlying mechanisms. Isolated segments of male rat abdominal aorta and mesenteric artery were suspended in a tissue bath, and the changes in arterial contraction/relaxation were measured. The α-adrenergic receptor agonist phenylephrine (Phe) (10^-9-10^-5 M) caused concentration-dependent aortic and mesenteric artery contraction that was reduced in tissues pretreated with SDX (1 mg/ml). In aortic and mesenteric arterial segments precontracted with submaximal concentration of Phe (3 × 10^-7-6 × 10^-7 M), SDX (0.001-1 mg/ml) caused concentration-dependent relaxation. To test the role of endothelium, SDX-induced relaxation was compared with that of acetylcholine (ACh), a known activator of endothelium-dependent relaxation. In Phe precontracted aorta, ACh relaxation was abolished and SDX relaxation was significantly inhibited by endothelium removal or the nitric oxide synthase (NOS) inhibitor N_ω-nitro-l-arginine methyl ester (L-NAME), suggesting a role of NO. In mesenteric artery, ACh relaxation was abolished by endothelium removal, partially blocked by L-NAME, and completely blocked by a mixture of indomethacin, a cyclooxygenase inhibitor and blocker of the PGI₂-cAMP pathway, and tetraethylammonium, a blocker of K⁺ channels and EDHF-dependent hyperpolarization pathway. In comparison, SDX relaxation of mesenteric artery was almost completely inhibited by endothelium removal or NOS inhibitor L-NAME. SDX enhanced vascular relaxation and increased nitrate/nitrite production in response to all ACh concentrations in the aorta, but only to low ACh concentrations (<10^-7 M) in mesenteric artery. SDX did not affect aortic or mesenteric artery endothelium-independent relaxation to the NO donor sodium nitroprusside. Thus, SDX promotes arterial relaxation via a mechanism involving endothelium-dependent NO production; an effect that could enhance vasodilation and decrease vasoconstriction in vascular disorders.

Sulodexide in venous disease

Sulodexide is a glycosaminoglycan extracted from porcine intestinal mucosa. The purpose of this review is to discuss sulodexide's complex pharmacological profile and its clinical applications for venous disease. Sulodexide has wide-ranging biological effects on the vascular system, including antithrombotic, profibrinolytic, anti-inflammatory, endothelial protective and vasoregulatory effects. Sulodexide has emerged as a potential therapeutic option for the management of chronic venous insufficiency, including venous ulceration, and the prevention of recurrent venous thromboembolism, with a low rate of major bleeding complications. Sulodexide's pleiotropic vascular effects may facilitate the management of common venous disorders.

Sulodexide inhibits angiogenesis via decreasing Dll4 and Notch1 expression in mouse proepicardial explant cultures

Sulodexide (SDX) is a mixed drug containing low-molecular-weight heparin sulfate and dermatan sulfate. It exerts mild anticoagulant action but can also affect leukocytes, macrophages, and cell-cell adhesion and may interact with growth factors although its direct influence on endothelial cells is not well described. Clinically, SDX is used for the treatment of cardiovascular diseases, where it exerts anti-inflammatory and endothelial protective effects. The aim of this study was to determine the influence of SDX on tubule formation and angiogenesis-related proteins' mRNA expression in endothelial cell line C166 and mouse proepicardial explants. C166 cells and explants were stimulated with a proangiogenic cocktail containing bFGF/VEGF-A₁₂₀ /VEGF-A₁₆₄ enriched with SDX. After stimulation, the number and morphology of tubules stained with anti-CD31 antibody were examined under confocal microscope and expression of mRNA for VEGF-A, VEGF-B, VEGF-C, bFGF, IGF-1, Dll4, and Notch1 was measured with real-time PCR. In C166 cell line, there was no difference in tubule formation and mRNA expression, but in proepicardial explants, we observed reduction in tubule number and in mRNA level for DLL4 and Notch1 after SDX administration. In conclusion, SDX indirectly inhibits angiogenesis in mouse proepicardial explant cultures but has no direct effect on the C166 endothelial cell line.

Pathophysiological Mechanisms of Chronic Venous Disease and Implications for Venoactive Drug Therapy

Chronic venous disease (CVD) is a common pathology, with significant physical and psychological impacts for patients and high economic costs for national healthcare systems. Throughout the last decades, several risk factors for this condition have been identified, but only recently, have the roles of inflammation and endothelial dysfunction been properly assessed. Although still incompletely understood, current knowledge of the pathophysiological mechanisms of CVD reveals several potential targets and strategies for therapeutic intervention, some of which are addressable by currently available venoactive drugs. The roles of these drugs in the clinical improvement of venous tone and contractility, reduction of edema and inflammation, as well as in improved microcirculation and venous ulcer healing have been studied extensively, with favorable results reported in the literature. Here, we aim to review these pathophysiological mechanisms and their implications regarding currently available venoactive drug therapies.

Sulodexide pretreatment attenuates renal ischemia-reperfusion injury in rats

Sulodexide is a potent antithrombin agent, however, whether it has beneficial effects on renal ischemia-reperfusion injury (IRI) remains unknown. In the present study, we assessed the therapeutic effects of sulodexide in renal IRI and tried to investigate the potential mechanism. One dose of sulodexide was injected intravenously in Sprague-Dawley rats 30 min before bilateral kidney ischemia for 45 min. The animals were sacrificed at 3h and 24h respectively. Our results showed that sulodexide pretreatment improved renal dysfunction and alleviated tubular pathological injury at 24h after reperfusion, which was accompanied with inhibition of oxidative stress, inflammation and cell apoptosis. Moreover, we noticed that antithrombin III (ATIII) was activated at 3h after reperfusion, which preceded the alleviation of renal injury. For in vitro study, hypoxia/reoxygenation (H/R) injury model for HK2 cells was carried out and apoptosis and reactive oxygen species (ROS) levels were evaluated after sulodexide pretreatment. Consistently, sulodexide pretreatment could reduce apoptosis and ROS level in HK2 cells under H/R injury. Taken together, sulodexide pretreatment might attenuate renal IRI through inhibition of inflammation, oxidative stress and apoptosis, and activation of ATIII.

Sulodexide prevents activation of the PLA2/COX-2/VEGF inflammatory pathway in human retinal endothelial cells by blocking the effect of AGE/RAGE

Diabetic retinopathy is characterized by the breakdown of endothelial blood-retinal barrier. We tested the hypothesis that sulodexide (SDX), a highly purified glycosaminoglycan composed of 80% iduronylglycosaminoglycan sulfate and 20% dermatan sulfate, protects human retinal endothelial cells (HREC) from high glucose (HG)-induced damage, through the suppression of inflammatory ERK/cPLA2/COX-2/PGE₂ pathway, by blocking the effect of advanced glycation end-products (AGEs). HREC were treated with HG (25mM) or AGEs (glycated-BSA, 2mg/ml) for 48h, with or without SDX (60μg/ml) or aflibercept (AFL, 40μg/ml), a VEGF-trap. SDX protected HREC from HG-induced damage (MTT and LDH release) and preserved their blood-retinal barrier-like properties (Trans Endothelial Electrical Resistance and junction proteins, claudin-5, VE-cadherin and occludin, immunofluorescence and immunoblot) as well as their angiogenic potential (Tube Formation Assay). Both HG and AGEs increased phosphoERK and phospho-cPLA₂, an effect counteracted by SDX and, less efficiently, by AFL. Both HG and exogenous VEGF (80ng/ml) increased PGE₂ release, an effect partially reverted by SDX for HG and by AFL for VEGF. Analysis of NFκB activity revealed that HG increased the abundance of p65 in the nuclear fraction (nuclear translocation), an effect entirely reverted by SDX, but only partially by AFL. SDX, AFL and SDX+AFL protected HREC even when added 24h after HG. These data show that SDX protects HREC from HG damage and suggest that it counteracts the activation of ERK/cPLA2/COX-2/PGE₂ pathway by reducing AGE-related signaling and downstream NFκB activity. This mechanism, partially distinct from VEGF blockade, may contribute to the therapeutic effect of SDX.

Sulodexide for treating venous leg ulcers

BACKGROUND

Venous leg ulcers are common, chronic wounds caused by venous diseases, with a high recurrence rate and heavy disease burden. Compression therapy (bandages or stockings) is the first choice treatment for venous leg ulcers. However, when ulcers remain unhealed, medication can also be used with or without compression therapy. Sulodexide, a highly purified glycosaminoglycan (a naturally occurring molecule) has antithrombotic and profibrinolytic properties (it reduces the formation of blood clots) as well as anti-inflammatory effects. Sulodexide has been studied as a potential treatment for venous leg ulcers.

OBJECTIVES

To assess the efficacy and safety of sulodexide for treating venous leg ulcers.

SEARCH METHODS

In July 2015 we searched: The Cochrane Wounds Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; EBSCO CINAHL; Chinese Biomedical Literature Database (CBM); China National Knowledge Infrastructure Database (CNKI); Wan Fang and VIP. We also searched clinical trials registries to identify ongoing studies, as well as references listed in relevant publications. There were no restrictions based on date of publication, language or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving people with a diagnosis of venous leg ulcers which compared sulodexide with placebo or any other drug therapy (such as pentoxifylline, flavonoids, aspirin), with or without compression therapy.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. The authors independently selected studies, extracted data and assessed risk of bias. We pooled data to present the risk ratio (RR) with 95% confidence interval (CI), or presented a narrative summary. We assessed overall evidence quality according to the GRADE approach.

MAIN RESULTS

We included four RCTs with a total of 463 participants (aged 42 years to 93 years); one report was only available as a published abstract.Meta-analysis of three RCTs suggests an increase in the proportion of ulcers completely healed with sulodexide as an adjuvant to local treatment (including wound care and compression therapy) compared with local treatment alone (rate of complete healing with sulodexide 49.4% compared with 29.8% with local treatment alone; RR 1.66; 95% CI 1.30 to 2.12). This evidence for sulodexide increasing the rate of complete healing is low quality due to risk of bias. It is unclear whether sulodexide is associated with any increase in adverse events (4.4% with sulodexide versus 3.1% with no sulodexide; RR 1.44; 95% CI 0.48 to 4.34). The evidence for adverse events is very low quality, downgraded twice for risk of bias and once for imprecision.

AUTHORS' CONCLUSIONS

Sulodexide may increase the healing of venous ulcers, when used alongside local wound care, however the evidence is only low quality and the conclusion is likely to be affected by new research. It is not clear whether sulodexide is associated with adverse effects. The standard dosage, route and frequency of sulodexide reported in the trials was unclear. Further rigorous, adequately powered RCTs examining the effects of sulodexide on healing, ulcer recurrence, quality of life and costs are necessary.

Superoxide dismutase 1 and glutathione peroxidase 1 are involved in the protective effect of sulodexide on vascular endothelial cells exposed to oxygen-glucose deprivation

Sulodexide (SDX) is widely used in the treatment of both arterial and venous thrombotic disorders. In addition to its recognized antithrombotic action, SDX has endothelial protective potential, which is independent of the coagulation/fibrinolysis system. However, the detailed molecular mechanisms of the endothelioprotective action of the drug are still unresolved. The aim of the present study was to determine whether treatment with SDX at concentrations of 0.125-0.5 lipase releasing unit (LRU)/ml have on the expression and activity of antioxidant enzymes in ischemic endothelial cells and how these effects might be related to the antiapoptotic properties of SDX. In the present study, human umbilical vein endothelial cells (HUVECs) were subjected to ischemia-simulating conditions (combined oxygen and glucose deprivation, OGD) for 6h to determine the protective effects of SDX. SDX (0.25 and 0.5LRU/ml) in OGD significantly increased the cell viability and prevented mitochondrial depolarization in the HUVECs. Moreover, SDX protected the HUVECs against OGD-induced apoptosis. At concentrations of 0.25 and 0.5LRU/ml, the drug increased both superoxide dismutase 1 (SOD1) and glutathione peroxidase 1 (GPx1) mRNA/protein expression together with a significant attenuation of oxidative stress in ischemic HUVECs. Our findings also demonstrate that an increase in both SOD and GPx activity is involved in the protective effect of SDX on ischemic endothelial cells. Altogether, these results suggest that SDX has a positive effect on ischemia-induced endothelial damage because of its antioxidant and antiapoptotic properties.

Diabetic nephropathy - complications and treatment

Diabetic nephropathy is a significant cause of chronic kidney disease and end-stage renal failure globally. Much research has been conducted in both basic science and clinical therapeutics, which has enhanced understanding of the pathophysiology of diabetic nephropathy and expanded the potential therapies available. This review will examine the current concepts of diabetic nephropathy management in the context of some of the basic science and pathophysiology aspects relevant to the approaches taken in novel, investigative treatment strategies.

Sulodexide as Adjunctive Therapy in Diabetic Foot Patients With Critical Limb Ischemia Treated With Percutaneous Transluminal Angioplasty

We evaluated the safety and efficacy of sulodexide, a biocompound of glycosamin-glicans, as adjunct medical therapy to percutaneous transluminal angioplasty (PTA) in diabetes mellitus (DM) patients with critical limb ischemia (CLI). We studied 27 consecutive DM patients with CLI successfully subjected to PTA who, on top of standard antiplatelet therapy, received sulodexide 25 mg bid, and were followed-up for 24 weeks, monitoring adverse events, transcutaneous oxygen tension (TcPO₂), ankle-brachial pressure index, pain, and ulcer dimension. At the end of follow-up, ulcer healing, amputation rates, and cardiovascular risk profile of patients were evaluated. Patients were compared with a historical superimposable control group that was treated for the same indications in the same way as the study group, except for sulodexide inception. No differences in ulcer healing and amputation rates were found at the end of follow-up between the groups. In the study group, TcPO₂ was significantly (P < .05) higher at the end of follow-up, and pain intensity was reduced more rapidly. Plasma fibrinogen and plasma creatinine concentration were significantly (P < .05) reduced in study group at the end of follow-up. No differences in adverse events were observed between the groups during follow-up. Our data suggest that sulodexide administration after PTA, on top of antiplatelet therapy, may improve the outcome of PTA in DM patients with CLI by improving microcirculatory function.

The effects of sulodexide on both clinical and molecular parameters in patients with mixed arterial and venous ulcers of lower limbs

BACKGROUND

Mixed venous and arterial ulcers account for approximately 15%-30% of all venous leg ulcerations. Several studies have shown that matrix metalloproteinases (MMPs) and neutrophil gelatinase-associated lipocalin (NGAL) play a central role in the pathophysiology of venous and arterial diseases. Some studies have shown the efficacy of glycosaminoglycans, such as sulodexide (SDX), in treating patients with leg ulcers. The aim of this study was to evaluate clinical effects of SDX and its correlation with MMPs and NGAL expression in patients with mixed arterial and venous leg ulcers.

METHODS

Patients eligible for this study were of both sexes, older than 20 years, and with a clinical and instrumental diagnosis of mixed ulcer.

RESULTS

Fifty-three patients of both sexes were enrolled and divided into two groups by means of randomization tables. Group A (treated group) comprised 18 females and ten males (median age: 68.7 years) treated with standard treatment (compression therapy and surgery) + SDX (600 lipoprotein lipase-releasing units/day intramuscularly) for 15 days followed by SDX 250 lipase-releasing units every 12 hours day orally for 6 months as adjunctive treatment. Group B (control group) comprised 17 females and eight males (median age: 64.2 years) treated with standard treatment only (compression therapy and surgery). The type of surgery was chosen according to anatomical level of vein incompetence: superficial venous open surgery and/or subfascial endoscopic perforating surgery. In all enrolled patients, blood samples were collected in order to evaluate the plasma levels of MMPs and NGAL through enzyme-linked immunosorbent assay. These results were compared to another control group (Group C) of healthy individuals. Moreover, biopsies of ulcers were taken to evaluate the tissue expression of MMPs and NGAL through Western blot analysis. Our results revealed that SDX treatment is able to reduce both plasma levels and tissue expression of MMPs improving the clinical conditions in patients with mixed ulcers.

CONCLUSION

Inhibition of MMPs could represent a possible therapeutic intervention to limit the progression of leg ulceration. In particular, our findings demonstrate the efficacy of SDX in patients with mixed arterial and venous chronic ulcers of the lower limbs.

Chronic kidney disease: a new look at pathogenetic mechanisms and treatment options

The concept of renoprotection has evolved significantly, driven by improved understanding of the pathophysiology of chronic kidney disease (CKD) and the advent of novel treatment options. Glomerular hyperfiltration, hypertension and proteinuria represent key mediators of CKD progression. It is increasingly recognized that proteinuria may actually be pathological and etiological in CKD progression and not just symptomatic. It initiates a sequence of events involving activation of proinflammatory and profibrotic signaling pathways in proximal tubular epithelial cells with transmission of the disease to the tubulointerstitium and progression to end-stage kidney disease (ESKD). Although the etiology and epidemiology of pediatric CKD differs to that in adults, studies in the various animal models of kidney disease, from obstructive uropathy to glomerulonephritis, have revealed that many common proinflammatory and profibrotic pathways are induced in progressive proteinuric CKD, irrespective of the primary disease. This pathomechanistic overlap therefore translates into the potential for common treatment targets for a wide spectrum of kidney diseases. In this review we therefore discuss the experimental and clinical evidence for an array of prospective future drug treatments of CKD progression. While conceptually promising, clear definitive evidence beyond preclinical data does not exist for many of these treatments, and others are limited by serious adverse effects. More studies are needed before general recommendations can be given.

Development and use of sulodexide in vascular diseases: implications for treatment

Sulodexide (SDX), a sulfated polysaccharide complex extracted from porcine intestinal mucosa, is a blend of two glycosaminoglycan (GAG) entities, namely a fast-moving heparin (HP) fraction and a dermatan sulfate (DS; 20%) component. The compound is unique among HP-like substances in that it is biologically active by both the parenteral and oral routes. A main feature of the agent is to undergo extensive absorption by the vascular endothelium. For this reason, in preclinical studies, SDX administered parenterally displays an antithrombotic action similar to that of HPs but associated with fewer alterations of the blood clotting mechanisms and tests, thus being much less conducive to bleeding risk than HPs. When given orally, SDX is associated with minimal changes in classic coagulation tests, but maintains a number of important effects on the structure and function of endothelial cells (EC), and the intercellular matrix. These activities include prevention or restoration of the integrity and permeability of EC, counteraction versus chemical, toxic or metabolic EC injury, regulation of EC-blood cell interactions, inhibition of microvascular inflammatory and proliferative changes, and other similar effects, thus allowing oral SDX to be considered as an endothelial-protecting agent. The best available clinical evidence of the efficacy of SDX administered orally with or without an initial parenteral phase is the following: alleviation of symptoms in chronic venous disease and especially acceleration of healing of venous leg ulcers; prevention of cardiovascular events in survivors after acute myocardial infarction; marked improvement of intermittent claudication in patients with peripheral occlusive arterial disease; and abatement of proteinuria in patients with diabetic nephropathy that may contribute to the amelioration or stabilization of kidney function. Although further clinical trials are warranted, SDX is presently widely accepted in many countries as an effective and safe long-term, endothelial-protecting drug.

Sulodexide modifies intravascular homeostasis what affects function of the endothelium

PURPOSE

Sulodexide is a mixture of heparin and dermatan sulphate which has an antithrombotic action. It was shown that it has also direct effect on the endothelial cells. We tested the effect of sulodexide on the intravascular homeostasis in patients with peripheral vascular disease.

METHODS

Sulodexide was infused iv. at a dose of 1200 Lipoprotein Lipase Releasing Units (LRU) in 10 patients with peripheral vascular disease. Blood samples were collected before the infusion and 1, 6 and 24 hours after the infusion. Inflammatory and fibrinolytic parameters were studied in the collected serum samples. Additionally, ex-vivo effect of the serum samples on in vitro function of the endothelial cells was studied.

RESULTS

Infusion of sulodexide caused acute and transient peak of the Hepatocyte Growth Factor (HGF) concentration in blood and decrease of the Vascular Endothelial Growth Factor (VEGF) level, what, as we found in in vitro experiments, was due to adsorption of VEGF to endothelium. We found that HGF enhanced in vitro stimulating effect of VEGF on proliferation of the endothelial cells. Serum level of interleukin-6 was gradually decreased, whereas fibrinolytic activity of serum, reflected by t-PA/PAI-1 ratio, increased. Serum samples obtained from the studied patients suppressed oxidative stress and release of interleukin-6 in endothelial cells maintained in in vitro culture.

CONCLUSION

Sulodexide reduces intravascular inflammation and suppresses inflammatory reaction in the endothelial cells; both effects are desirable in patients with peripheral vascular disease.

Inflammatory factor-specific sumoylation regulates NF-κB signalling in glomerular cells from diabetic rats

OBJECTIVE

The activation of nuclear factor (NF)-κB by cytokines under hyperglycaemic conditions is a potential mechanism for complications in diabetes. We investigated whether small ubiquitin-like modifier 4 (SUMO4) regulates renal NF-κB signalling in diabetic rats.

METHODS

Histological changes in kidney were analysed in diabetic GK rats. The expressions of tumour necrosis factor (TNF)-α, NF-κB (p65), IκBα and SUMO4 in renal tissues were examined by immunohistochemistry and Western blotting. Primary cultured glomerular endothelial cells from rats were stimulated by TNF-α or interleukin (IL)-2.

RESULTS

The renal expression of TNF-α, NF-κB (p65), IκBα and SUMO4 was significantly higher in diabetic GK rats than in control rats. In control rats, no nuclear translocation was observed for IκBα or NF-κB (p65). However, in diabetic GK rats, translocation of NF-κB (p65) and IκBα into the nucleus was observed, and the expression of SUMO4 and IκBα was up-regulated in the glomerular endothelial cells. SUMO4 was localised in both the cytoplasm and nucleus, while IκBα was predominantly located in the nucleus after stimulation with TNF-α. In contrast, SUMO4 was localised in the nucleus, and increased cytoplasm SUMO4 localisation was found after stimulation with IL-2.

CONCLUSIONS

SUMO4 plays a role in regulating NF-κB signalling in glomerular cells. Cytokines have a unique effect in regulating the sumoylation of NF-κB.

Sulodexide in the treatment of chronic venous disease

Chronic venous disease encompasses a range of venous disorders, including those involving the lower limbs resulting from venous hypertension. The spectrum of chronic venous disease signs and symptoms shows variable severity, ranging from mild (aching, pain, and varicose veins) to severe (venous ulcers). The pathophysiology of chronic venous disease is characterized by venous hypertension, which triggers endothelial dysfunction and inflammation leading to microcirculatory and tissue damage, and eventually to varicose veins and venous ulcers. Sulodexide is an orally active mixture of glycosaminoglycan (GAG) polysaccharides with established antithrombotic and profibrinolytic activity. The agent is used in the treatment of a number of vascular disorders with increased risk of thrombosis, including intermittent claudication, peripheral arterial occlusive disease and post-myocardial infarction. Sulodexide differs from heparin because it is orally bioavailable and has a longer half-life and a smaller effect on systemic clotting and bleeding. An increasing body of preclinical evidence shows that sulodexide also exerts anti-inflammatory, endothelial-protective, and pleiotropic effects, supporting its potential efficacy in the treatment of chronic venous disease. Clinical studies of sulodexide have shown that the agent is associated with significant improvements in the clinical signs and symptoms of venous ulcers, and is therefore a recommended therapy in combination with local wound care and bandages for patients with persistent venous leg ulcers. Preliminary evidence supports the use of sulodexide in the prevention of recurrent deep venous thrombosis. Sulodexide was generally safe and well tolerated in clinical trials, without hemorrhagic complications. Sulodexide therefore appears to be a favorable option for the treatment of all stages of chronic venous disease and for the prevention of disease progression.

Treatment of 5/6 nephrectomy rats with sulodexide: a novel therapy for chronic renal failure

AIM

Sulodexide, a glycosaminoglycan, could reduce albuminuria in diabetic patients. The aim of this study was to determine whether sulodexide could be used to treat chronic kidney failure in rats.

METHODS

Sixty Wistar rats undergone 5/6 nephrectomy, then were randomly divided into 4 groups: the model group, sulodexide group (sulodexide 5 mg/kg per day, im), irbesartan group irbesartan (20 mg/kg per day, ig) and sulodexide plus irbesartan group. Another 12 rats were enrolled into the sham operation group. After the treatments for 4, 8 and 12 weeks, urinary protein and serum creatinine levels were measured. After 12 weeks, serum cholesterin and triglycerides levels were measured, and the degrees of glomerular sclerosis and renal tubulointerstitial fibrosis were scored. The expression of aminopeptidase P (JG-12) in the renal tissue was examined using immunohistochemical staining. The renal expressions of endothelial nitric oxide synthase (eNOS) and tissue type plasminogen activator (tPA) were detected with RT-PCR and Western blot.

RESULTS

Proteinuria was markedly attenuated in the sulodexide-treated groups. After 4 and 8 weeks only the sulodexide-treated groups showed significant reduction in serum creatinine; while after 12 weeks all the three treatment groups showed significant reduction in serum creatinine. Furthermore, all the three treatment groups showed significant reduction in the scores of glomerular sclerosis and tubulointerstitial fibrosis. The glomerular expression of JG-12 was increased in both the sulodexide group and the sulodexide plus irbesartan group, but not in the irbesartan group. The eNOS mRNA and protein expression was decreased and the tPA mRNA and protein expression was significantly increased in the model group compared with Sham group. Sulodexide, irbesartan, and their combination reversed the decrease of eNOS expression but increased the tPA expression much more compared with model group.

CONCLUSION

Sulodexide was similar to irbesartan that can decrease proteinuria and attenuate renal lesions in 5/6 nephrectomy rats. The renal protection by sulodexide might be achieved via its impact on renal vascular endothelial cells.

Sulodexide reduces senescence-related changes in human endothelial cells

Background

Senescent endothelial cells acquire functional properties that make the vascular wall more prone to atherosclerotic changes. We tested whether senescence of the endothelial cells maintained in in vitro culture can be moderated by their simultaneous exposure to sulodexide.

Material/Methods

Replicative aging of the endothelial cells was studied during their 15 passages performed every 4 days in cells cultured in standard medium or in medium supplemented with sulodexide 0.5 LRU/mL. Changes in population doubling time and β-galactosidase activity were used as indexes of aging and compared with other cellular parameters.

Results

Repeated passages of endothelial cells induce their senescence, as reflected by prolongation of the population doubling time, increased β-galactosidase activity, oxidative stress and release of cytokines. Healing of the injured endothelial monolayer is impaired in senescent cells. Sulodexide partially prevents oxidative stress and totally eliminates other senescence-related changes such as increased release of MCP-1, lengthening of the population doubling time, and impaired healing of the cellular monolayer after its mechanical injury.

Conclusions

Sulodexide prevented cellular senescence in cultured endothelial cells, moderating features of the cellular senescence in endothelial cells in in vitro conditions, which potentially may have practical application. The administration of sulodexide could potentially be used in prevention of atherosclerotic changes.

Sulodexide prevents peripheral nerve damage in streptozotocin induced diabetic rats

We investigated whether sulodexide has additional protective effects against peripheral nerve damage caused by microvascular dysfunction in a rat model of diabetes. Female Sprague-Dawley (SD) rats were divided into the following 4 groups (n=7-9/group): Normal, Normal+Sulodexide (sulodexide 10mg/kg), diabetic group, and diabetic+Sulodexide (sulodexide 10mg/kg). We assessed current perception threshold, skin blood flow, superoxide dismutase, and proteinuria in experimental rats after oral administration of sulodexide for 20 weeks. We also performed morphometric analysis of sciatic nerves and intraepidermal nerve fibers of the foot. Superoxide dismutase activity in the blood and sciatic nerve were increased significantly after sulodexide treatment in the diabetic group. Current perception threshold was reduced at 2000 Hz (633.3 ± 24.15 vs 741.2 ± 23.5 μA, P<0.05) and skin blood flow was improved (10.90 ± 0.67 vs 8.85 ± 0.49 TPU, P<0.05) in the diabetic+Sulodexide group compared with the diabetic group. The mean myelinated axon area was significantly larger (56.6 ± 2.2 vs 49.8 ± 2.7 μm(2), P<0.05) and the intraepidermal nerve fiber density was significantly less reduced (6.27 ± 0.24 vs 5.40 ± 0.25/mm, P<0.05) in the diabetic+Sulodexide group compared to the diabetic group. Our results demonstrate that sulodexide exhibits protective effects against peripheral nerve damage in a rat experimental model of diabetes. Therefore, these findings suggest that sulodexide is a potential new therapeutic agent for diabetic peripheral neuropathy.

Effect of sulodexide on endothelial glycocalyx and vascular permeability in patients with type 2 diabetes mellitus

AIMS/HYPOTHESIS

Endothelial glycocalyx perturbation contributes to increased vascular permeability. In the present study we set out to evaluate whether: (1) glycocalyx is perturbed in individuals with type 2 diabetes mellitus, and (2) oral glycocalyx precursor treatment improves glycocalyx properties.

METHODS

Male participants with type 2 diabetes (n = 10) and controls (n = 10) were evaluated before and after 2 months of sulodexide administration (200 mg/day). The glycocalyx dimension was estimated in two different vascular beds using sidestream dark field imaging and combined fluorescein/indocyanine green angiography for sublingual and retinal vessels, respectively. Transcapillary escape rate of albumin (TER(alb)) and hyaluronan catabolism were assessed as measures of vascular permeability.

RESULTS

Both sublingual dimensions (0.64 [0.57-0.75] μm vs 0.78 [0.71-0.85] μm, p < 0.05, medians [interquartile range]) and retinal glycocalyx dimensions (5.38 [4.88-6.59] μm vs 8.89 [4.74-11.84] μm, p < 0.05) were reduced in the type 2 diabetes group compared with the controls whereas TER(alb) was increased (5.6 ± 2.3% vs 3.7 ± 1.7% in the controls, p < 0.05). In line with these findings, markers of hyaluronan catabolism were increased with diabetes (hyaluronan 137 ± 29 vs 81 ± 8 ng/ml and hyaluronidase 78 ± 4 vs 67 ± 2 U/ml, both p < 0.05). Sulodexide increased both the sublingual and retinal glycocalyx dimensions in participants with diabetes (to 0.93 [0.83-0.99] μm and to 5.88 [5.33-6.26] μm, respectively, p < 0.05). In line, a trend towards TER(alb) normalisation (to 4.0 ± 2.3%) and decreases in plasma hyaluronidase (to 72 ± 2 U/ml, p < 0.05) were observed in the diabetes group.

CONCLUSION/INTERPRETATION

Type 2 diabetes is associated with glycocalyx perturbation and increased vascular permeability, which are partially restored following sulodexide administration. Further studies are warranted to determine whether long-term treatment with sulodexide has a beneficial effect on cardiovascular risk.

TRIAL REGISTRATION

www.trialregister.nl NTR780/ http://isrctn.org ISRCTN82695186

FUNDING

An unrestricted Novartis Foundation for Cardiovascular Excellence grant (2006) to M. Nieuwdorp/E. S. G. Stroes, Dutch Heart Foundation (grant number 2005T037).

Preclinical and clinical evidence of nephro- and cardiovascular protective effects of glycosaminoglycans

Despite advances in pharmacological treatment, diabetic nephropathy is still the leading cause of end-stage renal disease and an important cause of morbidity and mortality in diabetics. Glycosaminoglycans are long, unbranched mucopolysaccharides that play an important role in establishing a charge-selective barrier that restricts the passage of negatively charged molecules, such as albumin and other proteins, at the level of the glomerular basal membrane. Their loss is associated with loss of selectivity and proteinuria. Extensive preclinical evidence and some clinical trials suggest that glycosaminoglycans replacement is associated with improvement of glomerular selectivity and of proteinuria. Sulodexide could also have some other effects, potentially useful to reduce the renal damage and the cardiovascular disease associated with proteinuria, such as improvement of haemorheological and blood lipid parameters, an endothelium protective effect and anti-inflammatory action. This review will discuss the evidence supporting the potential nephroprotective effects of sulodexide and other glycosaminoglycans.

Nephroprotective action of glycosaminoglycans: why the pharmacological properties of sulodexide might be reconsidered

A relatively large body of evidence supports the notion that glomerular capillary wall and mesangial alterations in diabetic nephropathy involve biochemical alterations of glycoproteins in these structures. Evidence in experimental animals rendered diabetic reveals that the administration of heparin and other anionic glycoproteins can effectively prevent the biochemical alterations that promote albuminuria. Moreover, angiotensin II inhibits heparan sulfate synthesis, while heparins modulate angiotensin II signaling in glomerular cells, inhibiting aldosterone synthesis and lowering proteinuria in diabetes patients. Sulodexide, a mixture of heparin and dermatan sulfate, appears to be a promising treatment for diabetic proteinuria partially resistant to renin-angiotensin system blocking agents. Sulodexide prevents heparan sulfate degradation, thus allowing reconstruction of heparan sulfate content and restoration of glomerular basement membrane ionic permselectivity. The antiproteinuric effect appears to be mainly related to the basal proteinuria and consequently to the duration of treatment in a relatively large number of small clinical trials. On the other hand, several sulodexide pharmacodynamic properties could improve the prognosis of chronic kidney disease patients, also independently from its antiproteinuric effect. However, sulodexide development as an antiproteinuric drug needs to be continued, in order to define which kind of patients could better respond to this treatment.