Sulodexide for kidney protection in type 2 diabetes patients with microalbuminuria: a randomized controlled trial

Chronic kidney disease in type 2 diabetes: The size of the problem, addressing residual renal risk and what we have learned from the CREDENCE trial

Chronic kidney disease (CKD) associated with type 2 diabetes (T2DM) is a global challenge; progression to end-stage kidney disease (ESKD) and increased risk of cardiovascular disease (CVD) associated with advancing nephropathy are a significant source of morbidity, mortality, and healthcare expenditure. Until recently, renin-angiotensin system (RAS) blockade was the mainstay of pharmacotherapy in diabetic kidney disease (DKD), representing a therapeutic paradigm shift towards interventions that delay disease progression independently of antihypertensive effects. However, a significant residual risk of DKD progression persisted in patients established on RAS blockade, highlighting the need for additional treatment options. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, originally licensed as glucose-lowering agents in people with T2DM, serendipitously demonstrated beneficial renal and cardiovascular outcomes in clinical trials designed primarily to evaluate their cardiovascular safety. The Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) trial was the first to study the effect of SGLT2 inhibition on a primary composite renal endpoint of ESKD, doubling of serum creatinine, or renal or cardiovascular death in 4401 people with T2DM and CKD established on RAS blockade. The trial was stopped early due to efficacy, demonstrating a 30% relative risk reduction in the primary endpoint in the canagliflozin group (hazard ratio 0.70, 95% confidence interval 0.59-0.82; p = 0.00001). Through discussion of the primary analysis from CREDENCE, and selected post hoc analyses, we review the significant benefits highlighted by this landmark study, its role in shaping clinical guidelines, and in re-establishing interest in interventions that reduce the residual risk of progression of DKD, alongside its interrelation with cardiovascular morbidity and heart failure. We also provide a brief narrative summary of key renal outcome trials since CREDENCE, which indicate emerging avenues for pharmacotherapy beyond SGLT2 inhibition.

Discovery and development of small-molecule heparanase inhibitors

Heparanase-1 (HPSE) is a promising yet challenging therapeutic target. It is the only known enzyme that is responsible for cleavage of heparan sulfate (HS) side chains from heparan sulfate proteoglycans (HSPGs), and is the key enzyme involved in the remodeling and degradation of the extracellular matrix (ECM). Overexpression of HPSE is found in various types of diseases, including cancers, inflammations, diabetes, and viral infections. Inhibiting HPSE can restore ECM functions and integrity, making the development of HPSE inhibitors a highly sought-after topic. So far, all HPSE inhibitors that have entered clinical trials belong to the category of HS mimetics, and no small-molecule or drug-like HPSE inhibitors have made similar progress. None of the HS mimetics have been approved as drugs, with some clinical trials discontinued due to poor bioavailability, side effects, and unfavorable pharmacokinetics characteristics. Small-molecule HPSE inhibitors are, therefore, particularly appealing due to their drug-like characteristics. Advances in the chemical spaces and drug design technologies, including the increasing use of in vitro and in silico screening methods, have provided new opportunities in drug discovery. This article aims to review the discovery and development of small-molecule HPSE inhibitors via screening strategies to shed light on the future endeavors in the development of novel HPSE inhibitors.

Glycosaminoglycans and fucoidan have a protective effect on experimental glomerulonephritis

Background: The glomerular endothelial glycocalyx is degraded during inflammation. The glycocalyx plays a pivotal role in endothelial function and is involved in many processes including binding of chemokines and cytokines, leukocyte trafficking, and preventing proteinuria. HS-based therapeutics are a promising novel class of anti-inflammatory drugs to restore a compromised endothelial glycocalyx under inflammatory conditions. Recently, we demonstrated that treatment with HS extracted from unstimulated glomerular endothelial glycocalyx (unstimulated HS_glx) reduced albuminuria during anti-GBM induced glomerulonephritis. Since endothelial HS domains are distinct in unstimulated versus inflammatory conditions, we hypothesized that 1) unstimulated HS_glx, 2) LPS-stimulated HS_glx, 3) the HS-mimetic fucoidan and 4) the glycosaminoglycan preparation sulodexide, which is a mixture of low molecular weight heparin and dermatan sulfate, might have different beneficial effects in experimental glomerulonephritis. Methods: The effect of unstimulated HS_glx, LPS HS_glx, Laminaria japonica fucoidan, or sulodexide on experimental glomerulonephritis was tested in LPS-induced glomerulonephritis in mice. Analyses included urinary albumin creatinine measurement, cytokine expression in plasma and renal cortex, and renal influx of immune cells determined by flow cytometry and immunofluorescence staining. Furthermore, the observed in vivo effects were evaluated in cultured glomerular endothelial cells and peripheral blood mononuclear cells by measuring cytokine and ICAM-1 expression levels. The ability of the compounds to inhibit heparanase activity was assessed in a heparanase activity assay. Results: Treatment of mice with LPS HS_glx or sulodexide near-significantly attenuated LPS-induced proteinuria. All treatments reduced plasma MCP-1 levels, whereas only fucoidan reduced IL-6 and IL-10 plasma levels. Moreover, all treatments reversed cortical ICAM-1 mRNA expression and both fucoidan and sulodexide reversed cortical IL-6 and nephrin mRNA expression. Sulodexide decreased renal influx of CD45⁺ immune cells whereas renal influx of macrophages and granulocytes remained unaltered for all treatments. Although all compounds inhibited HPSE activity, fucoidan and sulodexide were the most potent inhibitors. Notably, fucoidan and sulodexide decreased LPS-induced mRNA expression of ICAM-1 and IL-6 by cultured glomerular endothelial cells. Conclusion: Our data show a potentially protective effect of glycosaminoglycans and fucoidan in experimental glomerulonephritis. Future research should be aimed at the further identification of defined HS structures that have therapeutic potential in the treatment of glomerular diseases.

Early diabetic kidney disease: Focus on the glycocalyx

The incidence of diabetic kidney disease (DKD) is sharply increasing worldwide. Microalbuminuria is the primary clinical marker used to identify DKD, and its initiating step in diabetes is glomerular endothelial cell dysfunction, particularly glycocalyx impairment. The glycocalyx found on the surface of glomerular endothelial cells, is a dynamic hydrated layer structure composed of pro-teoglycans, glycoproteins, and some adsorbed soluble components. It reinforces the negative charge barrier, transduces the shear stress, and mediates the interaction of blood corpuscles and podocytes with endothelial cells. In the high-glucose environment of diabetes, excessive reactive oxygen species and proinflammatory cytokines can damage the endothelial glycocalyx (EG) both directly and indirectly, which induces the production of microalbuminuria. Further research is required to elucidate the role of the podocyte glycocalyx, which may, together with endothelial cells, form a line of defense against albumin filtration. Interestingly, recent research has confirmed that the negative charge barrier function of the glycocalyx found in the glomerular basement membrane and its repulsion effect on albumin is limited. Therefore, to improve the early diagnosis and treatment of DKD, the potential mechanisms of EG degradation must be analyzed and more responsive and controllable targets must be explored. The content of this review will provide insights for future research.

Early growth response factor 1 upregulates pro-fibrotic genes through activation of TGF-β1/Smad pathway via transcriptional regulation of PAR1 in high-glucose treated HK-2 cells

Tubulointerstitial fibrosis (TIF) makes a key role in diabetic kidney disease (DKD). In this study, we revealed that the expressions of Egr1 and protease-activated receptor 1 (PAR1) were increased in renal tissues of DKD rats. In vitro experiments demonstrated that both Egr1 overexpression and high glucose (HG) condition could promote the expressions of PAR1, fibronectin (FN) and collagen I (COL I). Furthermore, HG stimulation enhanced the binding capacity of Egr1 to PAR1 promoter. Both HG condition and Egr1 upregulation could increase, and thrombin inhibitor did not affect activity of TGF-β1/Smad pathway via PAR1. Collectively, Egr1 is involved in TIF of DKD partly through activating TGF-β1/Smad pathway via transcriptional regulation of PAR1 in HG treated HK-2 cells.

Diabetic nephropathy: Focusing on pathological signals, clinical treatment, and dietary regulation

Diabetic nephropathy (DN) is one of the most severe complications of diabetes. However, due to its complex pathological mechanisms, no effective therapeutic methods (other than ACEIs and ARBs) have been applied, which have been used for many years in clinical practice. Recent studies have shown that emerging therapeutics, including novel target-based pharmacotherapy, cell therapies, and dietary regulation, are leading to new hopes for DN management. This review aims to shed new light on the treatment of DN by describing the important pathological mechanisms of DN and by analysing recent advances in clinical treatment, including drug therapy, cell therapy, and dietary regulation. In pathological mechanisms, RAAS activation, AGE accumulation, and EMT are involved in inflammation, cellular stress, apoptosis, pyroptosis, and autophagy. In pharmacotherapy, several new therapeutics, including SGLT2 inhibitors, GLP-1 agonists, and MRAs, are receiving public attention. In addition, stem cell therapies and dietary regulation are also being emphasized. Herein, we highlight the importance of combining therapy and dietary regulation in the treatment of DN and anticipate more basic research or clinical trials to verify novel strategies.

A Dietary Supplement Containing Fucoidan Preserves Endothelial Glycocalyx through ERK/MAPK Signaling and Protects against Damage Induced by CKD Serum

(1) Damage to the endothelial glycocalyx (eGC), a protective layer lining the endothelial luminal surface, is associated with chronic kidney disease (CKD), which leads to a worsening of cardiovascular outcomes in these patients. Currently, there are no targeted therapeutic approaches. Whether the dietary supplement Endocalyx^TM (ECX) protects against endothelial damage caused by uremic toxins is unknown. (2) We addressed this question by performing atomic force microscopy measurements on living endothelial cells. We examined the effect of ECX on eGC thickness at baseline and with pooled serum from hemodialysis patients. ECX was also successfully administered in vivo in mice, in which eGC was assessed using perfused boundary region measurements by intravital microscopy of cremasteric vessels. (3) Both ECX and fucoidan significantly improved baseline eGC thickness. Our data indicate that these effects are dependent on ERK/MAPK and PI3K signaling. After incubation with eGC damaging serum from dialysis patients, ECX increased eGC height. Intravital microscopy in mice revealed a relevant increase in baseline eGC dimensions after feeding with ECX. (4) We identified a dietary supplement containing glycocalyx substrates and fucoidan as potential mediators of eGC preservation in vitro and in vivo. Our findings suggest that fucoidan may be an essential component responsible for protecting the eGC in acute settings. Moreover, ECX might contribute to both protection and rebuilding of the eGC in the context of CKD.

Present and future directions in diabetic kidney disease

Diabetic kidney disease (DKD) is the leading cause of kidney failure and is associated with substantial risk of cardiovascular disease, morbidity, and mortality. Traditionally, DKD prevention and management have focused on addressing hyperglycemia, hypertension, obesity, and renin-angiotensin system activation as important risk factors for disease. Over the last decade, sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists have been shown to meaningfully reduce risk of diabetes-related kidney and cardiovascular complications. Additional agents demonstrating benefit in DKD such as non-steroidal mineralocorticoid receptor antagonists and endothelin A receptor antagonists are further contributing to the growing arsenal of DKD therapies. With the availability of greater therapeutic options comes the opportunity to individually optimize DKD prevention and management. Novel applications of transcriptomic, proteomic, and metabolomic/lipidomic technologies, as well as use of artificial intelligence and reinforced learning methods through consortia such as the Kidney Precision Medicine Project and focused studies in established cohorts hold tremendous promise for advancing our understanding and treatment of DKD. Specifically, enhanced understanding of the molecular mechanisms underlying DKD pathophysiology may allow for the identification of new mechanism-based DKD subtypes and the development and implementation of targeted therapies. Implementation of personalized care approaches has the potential to revolutionize DKD care.

Hydrodynamic model for renal microvascular filtration: Effects of physiological and hemodynamic changes on glomerular size-selectivity

OBJECTIVE

The first step in renal urine formation is ultrafiltration across the glomerular barrier. The change in its nanostructure has been associated with nephrotic syndromes. Effects of physiological and hemodynamic factor alterations associated with diabetic nephropathy (DN) on glomerular permselectivity are examined through a mathematical model employing low-Reynolds-number hydrodynamics and hindered transport theory.

METHODS

Glomerular capillaries are represented as networks of cylindrical tubes with multilayered walls. Glomerular basement membrane (GBM) is a fibrous medium with bimodal fiber sizes. Epithelial slit fiber spacing follows a lognormal distribution based on reported electron micrographs with the highest resolution. Endothelial fenestrae are filled with fibers the size of glycosaminoglycans (GAGs). Effects of fiber-macromolecule steric and hydrodynamic interactions are included. Focusing on diabetic nephropathy, the physiological and hemodynamic factors employed in the computation are those reported for healthy humans and patients with early-but-overt diabetic nephropathy. The macromolecule concentration is obtained as a finite element solution of the convection-diffusion equation.

RESULTS

Computed sieving coefficients averaged along the capillary length agree well with ficoll sieving coefficients from studies in humans for most solute radii. GBM thickening and the loss of the slit diaphragm hardly affect glomerular permselectivity. GAG volume fraction reduction in the endothelial fenestrae, however, significantly increases macromolecule filtration. Increased renal plasma flow rate (RPF), glomerular hypertension, and reduction of lumen osmotic pressure cause a slight sieving coefficient decrease. These effects are amplified by an increased macromolecule size.

CONCLUSION

Our results indicate that glomerular hypertension and the reduction in the oncotic pressure decreases glomerular macromolecule filtration. Reduction of RPF and changes in the glomerular barrier structure associated with DN, however, increase the solute sieving. Damage to GAGs caused by hyperglycemia is likely to be the most prominent factor affecting glomerular size-selectivity.

Novel biomarkers for diabetic kidney disease

Although diabetic kidney disease (DKD) remains one of the leading causes of reduced lifespan in patients with diabetes mellitus; its prevalence has failed to decline over the past 30 years. To identify those at high risk of developing DKD and disease progression at an early stage, extensive research has been ongoing in the search for prognostic and surrogate endpoint biomarkers for DKD. Although biomarkers are not used routinely in clinical practice or prospective clinical trials, many biomarkers have been developed to improve the early identification and prognostication of patients with DKD. Novel biomarkers that capture one specific mechanism of the DKD disease process have been developed, and studies have evaluated the prognostic value of assay-based biomarkers either in small sets or in combinations involving multiple biomarkers. More recently, several studies have assessed the prognostic value of omics- based biomarkers that include proteomics, metabolomics, and transcriptomics. This review will first describe the biomarkers used in current practice and their limitations, and then summarize the current status of novel biomarkers for DKD with respect to assay- based protein biomarkers, proteomics, metabolomics, and transcriptomics.

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.

Sodium glucose cotransporter-2 inhibitors protect the cardiorenal axis: Update on recent mechanistic insights related to kidney physiology

Sodium glucose cotransporter-2 (SGLT2) inhibitors have acquired a central role in the treatment of type 2 diabetes, chronic kidney disease including diabetic kidney disease, and heart failure with reduced ejection fraction. SGLT2 inhibitors lower glucose levels by inducing glycosuria. In addition, SGLT2 inhibitors improve cardiovascular outcomes (3-point MACE), end-stage kidney disease, hospitalization for heart failure, and cardiovascular mortality in people with and without diabetes. The mechanisms underlying these benefits have been extensively investigated, but remain poorly understood. In this review, we first summarize recent trial evidence and subsequently focus on (1) the mechanisms by which SGLT2 inhibitors improve kidney outcomes and (2) the potential role of the kidneys in mediating the cardioprotective effects of SGLT2 inhibitors.

Heterologous production of chondroitin

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Chondroitin sulfate (CS) is a glycosaminoglycan with a growing variety of applications.

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CS can be produced from microbial fermentation of native or engineered strains.

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Synthetic biology tools are being used to improve CS yields in different hosts.

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Integrated polymerization and sulfation can generate cost-effective CS.

Chondroitin sulfate (CS) is a glycosaminoglycan with a broad range of applications being a popular dietary supplement for osteoarthritis. Usually, CS is extracted from animal sources. However, the known risks of animal products use have been driving the search for alternative methods and sources to obtain this compound. Several pathogenic bacteria naturally produce chondroitin-like polysaccharides through well-known pathways and, therefore, have been the basis for numerous studies that aim to produce chondroitin using non-pathogenic hosts. However, the yields obtained are not enough to meet the high demand for this glycosaminoglycan. Metabolic engineering strategies have been used to construct improved heterologous hosts. The identification of metabolic bottlenecks and regulation points, and the screening for efficient enzymes are key points for constructing microbial cell factories with improved chondroitin yields to achieve industrial CS production. The recent advances on enzymatic and microbial strategies to produce non-animal chondroitin are herein reviewed. Challenges and prospects for future research are also discussed.

From salt to hypertension, what is missed?

Excess salt intake is viewed as a major contributor to hypertension and cardiovascular disease, and dietary salt restriction is broadly recommended by public health guidelines. However, individuals can have widely varying physiological responses to salt intake, and a tailored approach to evaluation and intervention may be needed. The traditional sodium related concepts are challenging to assess clinically for two reasons: (1) spot and 24-hour urine sodium are frequently used to evaluate salt intake, but are more suitable for population study, and (2) some adverse effects of salt may be blood pressure-independent. In recent years, previously unknown mechanisms of sodium absorption and storage have been discovered. This review will outline the limitations of current methods to assess sodium balance and discuss new potential evaluation methods and treatment targets.

Sulodexide for Diabetic-Induced Disabilities: A Systematic Review and Meta-Analysis

INTRODUCTION

Micro- and macrovascular complications of diabetes are leading morbidities in the world population. They are responsible not only for increased mortality but also severe disabilities, which jeopardize quality of life (e.g., blindness, walking limitations, and renal failure requiring dialysis). The new antidiabetic agents (e.g., glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter inhibitors) are increasingly recognized as breakthrough agents in the treatment of diabetes and prevention of diabetic complications. However, drugs effective in preventing and treating diabetic disabilities are still needed and sulodexide could be one of those able to address the unmet clinical needs of the new antidiabetic agents.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the World Health Organization (WHO) International Clinical Trials Registry Platform Search Portal. We also manually searched potentially relevant journals, conference proceedings, and journal supplements. Any study monitoring any effect of sulodexide in subjects with diabetes, in relation to renal, vascular, and ocular complication, was considered. Treatment effects were estimated using standardized mean differences (SMDs), mean differences (MDs), and risk ratios (RRs), as appropriate. We calculated 95% confidence interval (CIs) and heterogeneity (Q, tau, and I²).

RESULTS

The search found 45 studies with 2817 participants (mean age 57 years; 63% male). The 26 randomized controlled studies included 2074 participants (mean age 58.8 years; 66% male). Sulodexide reduced the impact of diabetic retinopathy; increased the pain-free and maximal walking distance in peripheral arterial disease; accelerated the healing of diabetes-associated trophic ulcers; and decreased the rate of albumin excretion in subjects with nephropathy. The risk of adverse events (AEs) was not different between sulodexide and controls.

CONCLUSION

Sulodexide has a beneficial effect on the ocular, peripheral arterial disease, trophic ulcers, and renal complications of diabetes without increasing the risk of AEs.

Protective Role of Sulodexide on Renal Injury Induced by Limb Ischemia-Reperfusion

Background

Though widely known as a potent antithrombin agent with protective effects on the kidney and other remote organs, it is currently ambiguous when it comes to sulodexide's function on ischemia-reperfusion (I/R) injury. With this research, we pursued to further explore how sulodexide exerts its influence on limb I/R injury, in which deleterious effects on the kidney were what we primarily focused on.

Methods

We randomized twenty-four C57BL/6 male rats into three groups, namely, sham operation group (control group), I/R group, and sulodexide pretreatment group. Hematoxylin and eosin staining was applied for discovery of renal histological changes. Serum creatinine (Cr) and serum urea nitrogen (BUN) were measured. Apoptotic parameters were detected by the TdT-mediated dUTP Nick-End Labeling method. To what extent and levels that antiapoptotic and proapoptotic proteins were expressed could be sensitively revealed by immunohistochemistry assay. Lipid peroxidation product propylene glycol and inflammatory factors were examined by enzyme-linked immunosorbent assay. Additionally, an extracorporeal hypoxia-reoxygenation (H/R) model of human renal proximal tubule epithelial HK2 cells was established. Our targets lay in cell proliferation and apoptosis, and we used western blotting to reflect apoptosis-related gene expression.

Results

The levels of serum BUN, Cr, and inflammatory factors in sulodexide-intervened rats manifested significant reduction when compared with the I/R group. Also, sulodexide could protect the kidney from histological changes and could effectively inhibit intraparenchymal apoptosis. Furthermore, adding 2 μl/mL or 5 μl/mL of sulodexide to H/R model cells in vitro gave rise to significant restoration of the degenerative proliferation capacity of the HK2 cells following H/R injury and late cellular apoptosis experienced dramatic reduction versus the H/R group. When treated with 5 μl/mL of sulodexide at a dose of 10 mg/kg, the levels of the antiapoptotic proteins were increased, while the proapoptotic proteins showed opposite trends. Notable escalation on antiapoptotic protein expression level, in contrast with the opposite trends exhibited in proapoptotic proteins, was observed with 5 μl/mL sulodexide pretreatment with the dosage being 10 mg/kg.

Conclusion

Sulodexide can protect against kidney damage caused by I/R injury of the lower limbs by enhancing cell proliferation, inhibiting apoptosis, reducing inflammatory reactions, and scavenging oxygen free radicals.

The Endothelial Glycocalyx as a Key Mediator of Albumin Handling and the Development of Diabetic Nephropathy

The endothelial glycocalyx is a complex mesh of proteoglycans, glycoproteins and other soluble components, which cover the vascular endothelium. It plays an important role in many physiological processes including vascular permeability, transduction of shear stress and interaction of blood cells and other molecules with the vascular wall. Its complex structure makes its precise assessment challenging, and many different visualization techniques have been used with varying results. Diabetes, one of the main disease models where disorders of the glycocalyx are present, causes degradation of the glycocalyx through a variety of molecular pathways and especially through oxidative stress due to the action of reactive oxygen species. As the glycocalyx has been primarily studied in the glomerular endothelium, more evidence points towards a vital role in albumin handling and, consequently, in diabetic nephropathy. Therefore, the maintenance or restoration of the integrity of the glycocalyx seems a promising therapeutic target. In this review, we consider the structural and functional capacities of the endothelial glycocalyx, the available methods for its evaluation, the mechanisms through which diabetes leads to glycocalyx degradation and albuminuria, and possible treatment options targeting the glycocalyx.

Sulodexide versus Control and the Risk of Thrombotic and Hemorrhagic Events: Meta-Analysis of Randomized Trials

Thrombotic cardiovascular disease (myocardial infarction [MI], stroke, and venous thromboembolism [VTE]) remains a major cause of death and disability. Sulodexide is an oral glycosaminoglycan containing heparan sulfate and dermatan sulfate. We conducted a systematic review and meta-analysis to determine the cardiovascular efficacy, and safety of sulodexide versus control in randomized controlled trials (RCTs). We searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials for RCTs reporting cardiovascular outcomes in patients receiving sulodexide versus control (placebo or no treatment). Outcomes included all-cause mortality, cardiovascular mortality, MI, stroke, deep vein thrombosis (DVT), pulmonary embolism, and bleeding. We used inverse variance random-effects models with odds ratio (OR) as the effect measure. After screening 360 records, 6 RCTs including 7,596 patients (median follow-up duration: 11.6 months) were included. Patients were enrolled for history of MI, VTE, peripheral arterial disease, or cardiovascular risk factors plus nephropathy. Use of sulodexide compared with control was associated with reduced odds of all-cause mortality (OR 0.67, 95% confidence interval [CI] 0.52–0.85, p = 0.001), cardiovascular mortality (OR 0.44, 95% CI 0.22–0.89, p = 0.02), and MI (OR 0.70, 95% CI 0.51–0.96, p = 0.03), and nonsignificantly reduced odds of stroke (OR 0.78, 95% CI 0.45–1.35, p = 0.38). Sulodexide was associated with significantly reduced odds of VTE (OR 0.44, 95% CI 0.24–0.81, p = 0.008), including DVT (OR 0.41, 95% CI 0.26–0.65, p < 0.001), but not pulmonary embolism (OR 0.92, 95% CI 0.40–2.15, p = 0.86). Bleeding events were not significantly different in the two groups (OR 1.14, 95% CI 0.47–2.74, p = 0.48). In six RCTs across a variety of clinical indications, use of sulodexide compared with placebo or no treatment was associated with reduced odds of all-cause mortality, cardiovascular mortality, MI, and DVT, without a significant increase in bleeding. Additional studies with this agent are warranted.

Endothelial glycocalyx restoration by growth factors in diabetic nephropathy

The endothelial glycocalyx (eGlx) constitutes the first barrier to protein in all blood vessels. This is particularly noteworthy in the renal glomerulus, an ultrafiltration barrier. Leakage of protein, such as albumin, across glomerular capillaries results in albumin in the urine (albuminuria). This is a hall mark of kidney disease and can reflect loss of blood vessel integrity in microvascular beds elsewhere. We discuss evidence demonstrating that targeted damage to the glomerular eGlx results in increased glomerular albumin permeability. EGlx is lost in diabetes and experimental models demonstrate loss from glomerular endothelial cells. Vascular endothelial growth factor (VEGF)A is upregulated in early diabetes, which is associated with albuminuria. Treatment with paracrine growth factors such as VEGFC, VEGF165b and angiopoietin-1 can modify VEGFA signalling, rescue albumin permeability and restore glomerular eGlx in models of diabetes. Manipulation of VEGF receptor 2 signalling, or a common eGlx biosynthesis pathway by these growth factors, may protect and restore the eGlx layer. This would help to direct future therapeutics in diabetic nephropathy.

Renal Effects of Sulodexide in Type 2 Diabetic Patients without Nephrotic Range Proteinuria

BACKGROUND

Glycosaminoglycan plays an important role in the maintenance of glomerular charge selectivity of diabetic nephropathy. Sulodexide, a mixture of naturally occurring glycosaminoglycan polysaccharide components, has shown a nephroprotective effect in an experimental model of diabetic nephropathy. Although sulodexide reduced albuminuria in patients with type 1 and type 2 diabetes, long-term effects in patients with type 2 diabetes with significant proteinuria have not been established.

OBJECTIVES

The study was aimed at investigating the effects of sulodexide on proteinuria and renal function in patients with type 2 diabetes and nephropathy.

METHODS

Fifty-two patients with proteinuria between 500 and 3000 mg/day received sulodexide 200 mg/day for 12 months, while 56 matched patients with type 2 diabetes constituted the control group. All patients received standard metabolic and blood pressure controls. Primary outcome was evaluated as percentage of reduced proteinuria compared with the control group. Renal function was assessed using estimated glomerular filtration rate (GFR).

RESULTS

Proteinuria significantly increased in the control group [0.9 (IQR 0.3 to 1.78) to 1.16 (IQR 0.44 to 2.23) g/gCr, P = 0.001], whereas it remained stable in the sulodexide group [0.66 (IQR 0.23 to 0.67) to 0.67 (IQR 0.17 to 1.51) g/gCr, P = 0.108]. At 12 months, proteinuria was higher by 19.4% (IQR 10.3 to 37.6) in the control group while proteinuria was lower by -17.7% (IQR -53.1 to 3.2) in the sulodexide group with a significant difference between groups (P = 0.001). Renal function was noted as a change of estimated GFR, and serum creatinine decreased significantly during the study in both groups but did not significantly differ between groups. No significant changes in the blood pressure, fasting plasma glucose, and hemoglobin A1C were reported.

CONCLUSION

In addition to standard treatment, sulodexide is efficient in maintaining proteinuria in patients with type 2 diabetes with nonnephrotic range proteinuria, but it did not provide an additional benefit concerning renal disease progression.

Clinical impact of tissue sodium storage

In recent times, the traditional nephrocentric, two-compartment model of body sodium has been challenged by long-term sodium balance studies and experimental work on the dermal interstitium and endothelial surface layer. In the new paradigm, sodium can be stored without commensurate water retention in the interstitium and endothelial surface layer, forming a dynamic third compartment for sodium. This has important implications for sodium homeostasis, osmoregulation and the hemodynamic response to salt intake. Sodium storage in the skin and endothelial surface layer may function as a buffer during periods of dietary depletion and excess, representing an extra-renal mechanism regulating body sodium and water. Interstitial sodium storage may also serve as a biomarker for sodium sensitivity and cardiovascular risk, as well as a target for hypertension treatment. Furthermore, sodium storage may explain the limitations of traditional techniques used to quantify sodium intake and determine infusion strategies for dysnatraemias. This review is aimed at outlining these new insights into sodium homeostasis, exploring their implications for clinical practice and potential areas for further research for paediatric and adult populations.

Endothelium structure and function in kidney health and disease

The kidney harbours different types of endothelia, each with specific structural and functional characteristics. The glomerular endothelium, which is highly fenestrated and covered by a rich glycocalyx, participates in the sieving properties of the glomerular filtration barrier and in the maintenance of podocyte structure. The microvascular endothelium in peritubular capillaries, which is also fenestrated, transports reabsorbed components and participates in epithelial cell function. The endothelium of large and small vessels supports the renal vasculature. These renal endothelia are protected by regulators of thrombosis, inflammation and complement, but endothelial injury (for example, induced by toxins, antibodies, immune cells or inflammatory cytokines) or defects in factors that provide endothelial protection (for example, regulators of complement or angiogenesis) can lead to acute or chronic renal injury. Moreover, renal endothelial cells can transition towards a mesenchymal phenotype, favouring renal fibrosis and the development of chronic kidney disease. Thus, the renal endothelium is both a target and a driver of kidney and systemic cardiovascular complications. Emerging therapeutic strategies that target the renal endothelium may lead to improved outcomes for both rare and common renal diseases.

Endothelial Toxicity of High Glucose and its by-Products in Diabetic Kidney Disease

Alterations of renal endothelial cells play a crucial role in the initiation and progression of diabetic kidney disease. High glucose per se, as well as glucose by-products, induce endothelial dysfunction in both large vessels and the microvasculature. Toxic glucose by-products include advanced glycation end products (AGEs), a group of modified proteins and/or lipids that become glycated after exposure to sugars, and glucose metabolites produced via the polyol pathway. These glucose-related endothelio-toxins notably induce an alteration of the glomerular filtration barrier by increasing the permeability of glomerular endothelial cells, altering endothelial glycocalyx, and finally, inducing endothelial cell apoptosis. The glomerular endothelial dysfunction results in albuminuria. In addition, high glucose and by-products impair the endothelial repair capacities by reducing the number and function of endothelial progenitor cells. In this review, we summarize the mechanisms of renal endothelial toxicity of high glucose/glucose by-products, which encompass changes in synthesis of growth factors like TGF-β and VEGF, induction of oxidative stress and inflammation, and reduction of NO bioavailability. We finally present potential therapies to reduce endothelial dysfunction in diabetic kidney disease.

Diabetic nephropathy: an insight into molecular mechanisms and emerging therapies

Introduction: Diabetic kidney disease (DKD) is a major cause of morbidity and mortality in diabetes and is the most common cause of proteinuric and non-proteinuric forms of end-stage renal disease (ESRD). Control of risk factors such as blood glucose and blood pressure is not always achievable or effective. Significant research efforts have attempted to understand the pathophysiology of DKD and develop new therapies. Areas covered: We review DKD pathophysiology in the context of existing and emerging therapies that affect hemodynamic and metabolic pathways. Renin-angiotensin system (RAS) inhibition has become standard care. Recent evidence for renoprotective activity of SGLT2 inhibitors and GLP-1 agonists is an exciting step forward while endothelin receptor blockade shows promise. Multiple metabolic pathways of DKD have been evaluated with varying success; including mitochondrial function, reactive oxygen species, NADPH oxidase (NOX), transcription factors (NF-B and Nrf2), advanced glycation, protein kinase C (PKC), aldose reductase, JAK-STAT, autophagy, apoptosis-signaling kinase 1 (ASK1), fibrosis and epigenetics. Expert opinion: There have been major advances in the understanding and treatment of DKD. SGLT2i and GLP-1 agonists have demonstrated renoprotection, with novel therapies under evaluation. Addressing the interaction between hemodynamic and metabolic pathways may help achieve prevention, attenuation or even reversal of DKD.

The Heparanase Inhibitor (Sulodexide) Decreases Urine Glycosaminoglycan Excretion and Mitigates Functional and Histological Renal Damages in Diabetic Rats

Background/objectives: Recent data suggest a role for heparanase in several proteinuric conditions. An increased glomerular heparanase expression is associated with loss of heparan sulfate in the glomerular basement membrane (GBM). The aim of the present study was to investigate the renal effects of heparanase inhibition in a diabetic experimental model.

Methods: Fifteen male Wistar rats (230 ± 20 g) were divided into three groups: 1) controls, 2) diabetics (STZ, 50 mg/kg, dissolved in saline, ip), 3) diabetics + heparanase inhibitor (Sulodexide 1/5 mg/kg per day, gavage). The treatment started on the 21st day, for 21 consecutive days. The rats were kept individually in a metabolic cage (8 AM-2 PM) and urine samples were collected on the 21st and 42nd day. At study end blood, urine and tissue samples were collected for biochemical (blood BUN and Cr, urine GAG and Protein) and histological analyses.

Results: The results of this study showed that the heparanase inhibitor (sulodexide) significantly decreased urine GAG and protein excretion, urine protein/creatinine ratio and serum BUN and Cr in streptozotocin-induced DN in the rats. Pathological changes were significantly alleviated in the DN rats having received the heparanase inhibitor (sulodexide).

Conclusion: Our data suggest that the heparanase inhibitor (sulodexide) is able to protect against functional and histopathological injury in DN.

Endothelin receptor-A mediates degradation of the glomerular endothelial surface layer via pathologic crosstalk between activated podocytes and glomerular endothelial cells

Emerging evidence of crosstalk between glomerular cells in pathological settings provides opportunities for novel therapeutic discovery. Here we investigated underlying mechanisms of early events leading to filtration barrier defects of podocyte and glomerular endothelial cell crosstalk in the mouse models of primary podocytopathy (podocyte specific transforming growth factor-β receptor 1 signaling activation) or Adriamycin nephropathy. We found that glomerular endothelial surface layer degradation and albuminuria preceded podocyte foot process effacement. These abnormalities were prevented by endothelin receptor-A antagonism and mitochondrial reactive oxygen species scavenging. Additional studies confirmed increased heparanase and hyaluronoglucosaminidase gene expression in glomerular endothelial cells in response to podocyte-released factors and to endothelin-1. Atomic force microscopy measurements showed a significant reduction in the endothelial surface layer by endothelin-1 and podocyte-released factors, which could be prevented by endothelin receptor-A but not endothelin receptor-B antagonism. Thus, our studies provide evidence of early crosstalk between activated podocytes and glomerular endothelial cells resulting in loss of endothelial surface layer, glomerular endothelial cell injury and albuminuria. Hence, activation of endothelin-1-endothelin receptor-A and mitochondrial reactive oxygen species contribute to the pathogenesis of primary podocytopathies in experimental focal segmental glomerulosclerosis.

Clinical Trials on Diabetic Nephropathy: A Cross-Sectional Analysis

INTRODUCTION

Treatment options and decisions are often based on the results of clinical trials. We have evaluated the public availability of results from completed, registered phase III clinical trials on diabetic nephropathy and current treatment options.

METHODS

This was a cross-sectional analysis in which STrengthening the Reporting of OBservational studies in Epidemiology criteria were applied for design and analysis. In June 2017, 34 completed phase III clinical trials on diabetic nephropathy in the ClinicalTrials. gov registry were identified and matched to publications in the ClinicalTrials.gov registry and to those in the PubMed and Google Scholar databases. If no publication was identified, the principal investigator was contacted. The ratio of published and non-published studies was calculated. Various parameters, including study design, drugs, and comparators provided, were analyzed.

RESULTS

Drugs/supplements belonged to 26 different categories of medications, with the main ones being angiotensin-converting enzyme inhibitors, angiotensin-II receptors blockers, and dipeptidyl-peptidase-4-inhibitors. Among the trials completed before 2016 (n = 32), 22 (69%) were published, and ten (31%) remained unpublished. Thus, data on 11 different interventions and more than 1000 patients remained undisclosed. Mean time to publication was 26.5 months, which is longer than the time constrictions imposed by the U.S. Food and Drug Administration Amendments Act. Most trials only showed weak effects on micro- and macroalbuminuria, with an absolute risk reduction of 1.0 and 0.3%, respectively, and the number needed to treat varied between 91 and 333, without any relevant effect on end-stage-renal disease by intensive glucose-lowering treatment. Comparison of the results, however, was difficult since study design, interventions, and the renal outcome parameters vary greatly between the studies.

CONCLUSION

Despite the financial and human resources involved and the relevance for therapeutic guidelines and clinical decisions, about one-third of phase III clinical trials on diabetic nephropathy remain unpublished. Interventions used in published trials showed a low efficacy on renal outcome.

FUNDING

Deutsche Forschungsgemeinschaft (DFG): SFB 1118.

Vorapaxar treatment reduces mesangial expansion in streptozotocin-induced diabetic nephropathy in mice

Background

Twenty years after the onset of diabetes, up to 40% of patients develop diabetic nephropathy. Protease-activated receptor-1 (PAR-1) has recently been shown to aggravate the development of experimental diabetic nephropathy. PAR-1 deficient mice develop less albuminuria and glomerular lesions and PAR-1 stimulation induces proliferation and fibronectin production in mesangial cells in vitro. Vorapaxar is a clinically available PAR-1 inhibitor which is currently used for secondary prevention of ischemic events.

Objectives

The aim of this study was to investigate in a preclinical setting whether vorapaxar treatment may be a novel strategy to reduce diabetes-induced kidney damage.

Results

While control treated diabetic mice developed significant albuminuria, mesangial expansion and glomerular fibronectin deposition, diabetic mice on vorapaxar treatment did not show any signs of kidney damage despite having similar levels of hyperglycemia.

Conclusions

These data show that PAR-1 inhibition by vorapaxar prevents the development of diabetic nephropathy in this preclinical animal model for type I diabetes and pinpoint PAR-1 as a novel therapeutic target to pursue in the setting of diabetic nephropathy.

Materials and Methods

22 C57Bl/6 mice were made diabetic using multiple low-dose streptozotocin injections (50 mg/kg) and 22 littermates served as non-diabetic controls. Four weeks after the induction of diabetes, 11 mice of each group were assigned to control or vorapaxar treatment. Mice were sacrificed after 20 weeks of treatment and kidney damage was evaluated.

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.

Diabetic nephropathy: Time to withhold development and progression - A review

The recent discoveries in the fields of pathogenesis and management of diabetic nephropathy have revolutionized the knowledge about this disease. Little was added to the management of diabetic nephropathy after the introduction of renin angiotensin system blockers. The ineffective role of the renin- angiotensin system blockers in primary prevention of diabetic nephropathy in type 1 diabetes mellitus necessitated the search for other early therapeutic interventions that target alternative pathogenic mechanisms. Among the different classes of oral hypoglycemic agents, recent studies highlighted the distinguished mechanisms of sodium glucose transporter 2 blockers and dipeptidyl peptidase-4 inhibitors that settle their renoprotective actions beyond the hypoglycemic effects. The introduction of antioxidant and anti-inflammatory agents to this field had also added wealth of knowledge. However, many of these agents are still waiting well-designed clinical studies in order to prove their beneficial therapeutic role. The aim of this review of literature is to highlight the recent advances in understanding the pathogenesis, diagnosis, the established and the potential renoprotective therapeutic agents that would prevent the development or the progression of diabetic nephropathy.

Heparanase: roles in cell survival, extracellular matrix remodelling and the development of kidney disease

Heparanase has regulatory roles in various processes, including cell communication, gene transcription and autophagy. In addition, it is the only known mammalian endoglycosidase that is capable of degrading heparan sulfate (HS). HS chains are important constituents and organizers of the extracellular matrix (ECM), and have a key role in maintaining the integrity and function of the glomerular filtration barrier. In addition, HS chains regulate the activity of numerous bioactive molecules, such as cytokines and growth factors, at the cell surface and in the ECM. Given the functional diversity of HS, its degradation by heparanase profoundly affects important pathophysiological processes, including tumour development, neovascularization and inflammation, as well as progression of kidney disease. Heparanase-mediated degradation and subsequent remodelling of HS in the ECM of the glomerulus is a key mechanism in the development of glomerular disease, as exemplified by the complete resistance of heparanase-deficient animals to diabetes and immune-mediated kidney disease. This Review summarizes the role of heparanase in the development of kidney disease, and its potential as a therapeutic target.

Heparanase-driven inflammation from the AGEs-stimulated macrophages changes the functions of glomerular endothelial cells

AIMS

Amounts of macrophages were infiltrated in glomeruli in diabetic nephropathy. Heparanase has been thought to be closely related to proteinuria. Our aims were to determine the effect of heparanase on the inflammation in AGEs-stimulated macrophages and its role on the functions of glomerular endothelial cells (GEnCs).

METHODS

The expression of inflammation cytokines in macrophages were assayed by q-RT PCR, western, and ELISA. Then western was used to measure the expression of RAGE and key proteins in NF-κB pathway in macrophages. The expression of the adherence molecules and tight junction proteins in GEnCs were assessed by western. The adherence of mononuclear cells to GEnCs were observed by HE staining and transendothelial FITC-BSA were tested for the permeability of GEnCs.

RESULTS

HPA siRNA and heparanase inhibitor sulodexide could attenuate the increasing inflammatory factors (TNF-α and IL-1β) in AGEs-stimulated macrophages. NF-κB inhibitor PDTC could also decrease the augmented inflammation cytokines through inhibiting the activation of the NF-κB pathway induced by AGEs. The phosphorylation of NF-κB signaling pathway could be also attenuated by HPA siRNA and sulodexide, the same to the receptor of AGEs RAGE. When the macrophage-conditioned culture medium were added to the glomerular endothelial cells, we found HPA siRNA and sulodexide groups could decrease the increasing adherence and permeability of GEnCs induced by AGEs.

CONCLUSIONS

Heparanase increases the inflammation in AGEs-stimulated macrophages through activating the RAGE-NF-κB pathway. Heparanase driven inflammation from AGEs-stimulated macrophages increases the adherence of GEnCs and augments the permeability of GEnCs.

Sulodexide Protects Renal Tubular Epithelial Cells from Oxidative Stress-Induced Injury via Upregulating Klotho Expression at an Early Stage of Diabetic Kidney Disease

The hypoalbuminuric effect of sulodexide (SDX) on diabetic kidney disease (DKD) was suggested by some clinical trials but was denied by the Collaborative Study Group. In this study, the diabetic rats were treated with SDX either from week 0 to 24 or from week 13 to 24. We found that 24-week treatment significantly decreased the urinary protein and HAVCR1 excretion, inhibited the interstitial expansion, and downregulated the renal cell apoptosis and interstitial fibrosis. Renoprotection was also associated with a reduction in renocortical/urinary oxidative activity and the normalization of renal klotho expression. However, all of these actions were not observed when SDX was administered only at the late stage of diabetic nephropathy (from week 13 to 24). In vitro, advanced glycation end products (AGEs) dose-dependently enhanced the oxidative activity but lowered the klotho expression in cultured proximal tubule epithelial cells (PTECs). Also, H₂O₂ could downregulate the expression of klotho in a dose-dependent manner. However, overexpression of klotho reduced the HAVCR1 production and the cellular apoptosis level induced by AGEs or H₂O₂. Our study suggests that SDX may prevent the progression of DKD at the early stage by upregulating renal klotho expression, which inhibits the tubulointerstitial injury induced by oxidative stress.

Protease-activated receptor-1 deficiency protects against streptozotocin-induced diabetic nephropathy in mice

Endogenously administered activated protein C ameliorates diabetic nephropathy (DN) in a protease-activated receptor-1 (PAR-1)-dependent manner, suggesting that PAR-1 activation limits the progression of DN. Activation of PAR-1 in fibroblast-like cells, however, induces proliferation and extracellular matrix production, thereby driving fibrotic disease. Considering the key role of mesangial proliferation and extracellular matrix production during DN, PAR-1 may in fact potentiate diabetes-induced kidney injury. To determine the net effect of PAR-1 in DN, streptozotocin-induced DN was studied in wild type and PAR-1 deficient mice. Subsequent mechanistic insight was obtained by assessing profibrotic responses of mesangial and tubular epithelial cells in vitro, following PAR-1 stimulation and inhibition. Despite having similar glucose levels, PAR-1 deficient mice developed less kidney damage after induction of diabetes, as evidenced by diminished proteinuria, plasma cystatin C levels, expansion of the mesangial area, and tubular atrophy. In vitro, PAR-1 signaling in mesangial cells led to increased proliferation and expression of matrix proteins fibronectin and collagen IV. Conversely, a reduction in both proliferation and fibronectin deposition was observed in diabetic PAR-1 deficient mice. Overall, we show that PAR-1 plays an important role in the development of DN and PAR-1 might therefore be an attractive therapeutic target to pursue in DN.

Blood pressure-lowering effects of sulodexide depend on albuminuria severity: post hoc analysis of the sulodexide microalbuminuria and macroalbuminuria studies

Aims

It has been suggested that sulodexide is able to lower blood pressure (BP). This may be attributed to its ability to restore the endothelial surface layer (ESL). As ESL perturbation is known to be related to the degree of kidney damage, we investigated whether albuminuria, reflecting ESL status, modified the BP‐lowering potential of sulodexide.

Methods

A post hoc analysis of the double‐blind, randomized, placebo‐controlled sulodexide microalbuminuria (Sun‐MICRO) and macroalbuminuria (Sun‐MACRO) studies, including 1056 microalbuminuric and 843 macroalbuminuric subjects with type 2 diabetes receiving maximal tolerated renin–angiotensin‐aldosterone system inhibitor therapy, was carried out. We compared the effect of placebo and sulodexide on systolic BP (SBP) among albuminuria groups.

Results

Analysis of covariance, including data from both trials, showed that baseline urine albumin‐to‐creatinine ratio (UACR) was the only modifier of the SBP response (interaction with treatment P = 0.001). In subjects with an UACR >1000 mg g^–1, sulodexide lowered SBP by 4.6 mmHg [95% confidence interval (CI) 3.6, 5.6; P < 0.001] compared with placebo, whereas a 2.3 mmHg (95% CI 0.9,3.7; P = 0.001) reduction was seen in subjects with a UACR of 300–1000 mg g^–1. Sulodexide did not lower SBP in subjects with a UACR <300 mg g^–1 (−0.2 mmHg, 95% CI −0.8, 0.5; P = 0.60). SBP‐lowering effects were not accompanied by changes in body weight.

Conclusion

The BP‐reducing potency of sulodexide is modified by the degree of albuminuria in subjects with type 2 diabetes. As ESL status deteriorates with increasing albuminuria and nephropathy severity, this suggests that ESL restoration may represent a new target for BP treatment in subjects with diabetic nephropathy.

Effectiveness of sulodexide might be associated with inhibition of complement system in hepatitis B virus-associated membranous nephropathy: An inspiration from a pilot trial

BACKGROUND

The activation of complement system is associated with the development of hepatitis B virus-associated membranous nephropathy (HBV-MN) and heparin could inhibit the activation of complement system.

METHODS

This was a three-center trial. Seventy-nine patients with HBV-MN participated in the study. The follow-up of the study consisted of two periods: Stage 1 (S1) and Stage 2 (S2). All patients received 0.5mg entecavir plus 150-300mg/day of irbesartan but sulodexide was prescribed during S1. They were randomized into 4 groups according to sulodexide dose: blank (Group 1), 250 lipasemic unit (lsu)/day for 1year (Group 2), 500 lsu/day for 1year (Group 3) and 1000 lsu/day for 6months followed by 250 lsu/day for 6months (Group 4). Major clinical outcomes were valid remission (VR): (1) urine albumin/creatinine ratio (UACR) <150mg/mmol and >50% decline of baseline; (2) albumin >35g/L; (3) glomerular filtration rate (GFR) >90ml/(min*1.73m(2)).

RESULTS

(1) Groups 3 and 4 had significantly lower UACR and higher albumin than did Groups 1 and 2 at major visits; (2) Groups 3 and 4 achieved more VR compared with Group 1 (42.1% and 60.0% vs. 9.1%, p both<0.05); (3) in Groups 3 and 4, instead of Groups 1 and 2, more C3 deposition in the kidney was observed in those achieving VR; (4) plasma C3a, C5a and C5b-9 decreased significantly in Groups 3 and 4 during S1.

CONCLUSIONS

(1) The prescription of both sulodexide and entecavir could improve the prognosis of patients with HBV-MN but their mechanisms might be different; (2) the renoprotection of sulodexide in HBV-MN might probably relate to the inhibition of complement system.

The next generation of therapeutics for chronic kidney disease

Chronic kidney disease (CKD) represents a leading cause of death in the United States. There is no cure for this disease, with current treatment strategies relying on blood pressure control through blockade of the renin-angiotensin system. Such approaches only delay the development of end-stage kidney disease and can be associated with serious side effects. Recent identification of several novel mechanisms contributing to CKD development - including vascular changes, loss of podocytes and renal epithelial cells, matrix deposition, inflammation and metabolic dysregulation - has revealed new potential therapeutic approaches for CKD. This Review assesses emerging strategies and agents for CKD treatment, highlighting the associated challenges in their clinical development.

Glycosaminoglycan remodeling during diabetes and the role of dietary factors in their modulation

Glycosaminoglycans (GAGs) play a significant role in various aspects of cell physiology. These are complex polymeric molecules characterized by disaccharides comprising of uronic acid and amino sugar. Compounded to the heterogeneity, these are variously sulfated and epimerized depending on the class of GAG. Among the various classes of GAG, namely, chondroitin/dermatan sulfate, heparin/heparan sulfate, keratan sulfate and hyaluronic acid (HA), only HA is non-sulfated. GAGs are known to undergo remodeling in various tissues during various pathophysiological conditions, diabetes mellitus being one among them. These changes will likely affect their structure thereby impinging on their functionality. Till date, diabetes has been shown to affect GAGs in organs such as kidney, liver, aorta, skin, erythrocytes, etc. to name a few, with deleterious consequences. One of the mainstays in the treatment of diabetes is though dietary means. Various dietary factors are known to play a significant role in regulating glucose homeostasis. Furthermore, in recent years, there has been a keen interest to decipher the role of dietary factors on GAG metabolism. This review focuses on the remodeling of GAGs in various organs during diabetes and their modulation by dietary factors. While effect of diabetes on GAG metabolism has been worked out quite a bit, studies on the role of dietary factors in their modulation has been few and far between. We have tried our best to give the latest reports available on this subject.

Sulodexide therapy for the treatment of diabetic nephropathy, a meta-analysis and literature review

Sulodexide is a heterogeneous group of sulfated glycosaminoglycans (GAGs) that is mainly composed of low-molecular-weight heparin. Clinical studies have demonstrated that sulodexide is capable of reducing urinary albumin excretion rates in patients with type 1 and type 2 diabetes, suggesting that sulodexide has renal protection. However, this efficacy remains inconclusive. In this article, we used meta-analysis to summarize the clinical results of all prospective clinical studies in order to determine the clinical efficacy and safety of sulodexide in diabetic patients with nephropathy. Overall, sulodexide therapy was associated with a significant reduction in urinary protein excretion. In the sulodexide group, 220 (17.7%) achieved at least a 50% decrease in albumin excretion rate compared with only 141 (11.5%) in the placebo. The odds ratio comparing proportions of patients with therapeutic success between the sulodexide and placebo groups was 3.28 (95% confidence interval, 1.34-8.06; P=0.01). These data suggest a renoprotective benefit of sulodexide in patients with diabetes and micro- and macroalbuminuria, which will provide important information for clinical use of this drug as a potential modality for diabetic nephropathy, specifically, the prevention of end-stage renal disease that is often caused by diabetes.

Therapies on the Horizon for Diabetic Kidney Disease

Diabetic nephropathy is rapidly becoming the major cause of end-stage renal disease and cardiovascular mortality worldwide. Standard of care therapies include strict glycemic control and blockade of the renin-angiotensin-aldosterone axis. While these treatments slow progression of diabetic nephropathy, they do not arrest or reverse it. Newer therapies targeting multiple molecular pathways involved in renal inflammation, fibrosis, and oxidative stress have shown promise in animal models. Subsequently, many of these agents have been investigated in clinical human trials with mixed results. In this review, we will discuss recent findings of novel agents used in the treatment of diabetic nephropathy.

The glycocalyx--linking albuminuria with renal and cardiovascular disease

Albuminuria is commonly used as a marker of kidney disease progression, but some evidence suggests that albuminuria also contributes to disease progression by inducing renal injury in specific disease conditions. Studies have confirmed that in patients with cardiovascular risk factors, such as diabetes and hypertension, endothelial damage drives progression of kidney disease and cardiovascular disease. A key mechanism that contributes to this process is the loss of the glycocalyx--a polysaccharide gel that lines the luminal endothelial surface and that normally acts as a barrier against albumin filtration. Degradation of the glycocalyx in response to endothelial activation can lead to albuminuria and subsequent renal and vascular inflammation, thus providing a pathophysiological framework for the clinical association of albuminuria with renal and cardiovascular disease progression. In this Review, we examine the likely mechanisms by which glycocalyx dysfunction contributes to kidney injury and explains the link between cardiovascular disease and albuminuria. Evidence suggests that glycocalyx dysfunction is reversible, suggesting that these mechanisms could be considered as therapeutic targets to prevent the progression of renal and cardiovascular disease. This possibility enables the use of existing drugs in new ways, provides an opportunity to develop novel therapies, and indicates that albuminuria should be reconsidered as an end point in clinical trials.

The blood pressure lowering potential of sulodexide--a systematic review and meta-analysis

AIMS

Sulodexide is a highly purified mixture of glycosaminoglycans that has been studied for its anti-albuminuric potential. Considering the effects of glycosaminoglycans on endothelial function and sodium homeostasis, we hypothesized that sulodexide may lower blood pressure (BP). In this meta-analysis, we therefore investigated the antihypertensive effects of sulodexide treatment.

METHODS

We selected randomized controlled trials that investigated sulodexide treatment of at least 4 weeks and measured BP at baseline and after treatment. Two reviewers independently extracted data on study design, risk of bias, population characteristics and outcome measures. In addition, we contacted authors and pharmaceutical companies to provide missing data.

RESULTS

Eight studies, totalling 3019 subjects (mean follow-up 4.4 months) were included. Mean age was 61 years and mean baseline BP was 135/75 mmHg. Compared with control treatment, sulodexide resulted in a significant systolic (2.2 mmHg [95% CI 0.3, 4.1], P = 0.02) and diastolic BP reduction (1.7 mmHg [95% CI 0.6, 2.9], P = 0.004). Hypertensive patients displayed the largest systolic BP and diastolic BP reductions (10.2/5.4 mmHg, P < 0.001). Higher baseline systolic and diastolic BP were significantly associated with larger systolic (r(2)=0.83, P < 0.001) and diastolic BP (r(2)=0.41, P = 0.02) reductions after sulodexide treatment. In addition, systolic (r(2)=0.41, P = 0.03) and diastolic BP reductions (r(2)=0.60, P = 0.005) were significantly associated with albuminuria reduction.

CONCLUSION

Our data suggest that sulodexide treatment results in a significant BP reduction, especially in hypertensive subjects. This indicates that endothelial glycosaminoglycans might be an independent therapy target in cardiovascular disease. Future studies should further address the BP lowering potential of sulodexide.

Improvements in the Management of Diabetic Nephropathy

The burden of diabetes mellitus is relentlessly increasing. Diabetic nephropathy is the most common cause of end-stage renal disease (ESRD) worldwide and a major cause of morbidity and mortality in patients with diabetes. The current standard therapy of diabetic nephropathy involves intensive treatment of hyperglycemia and strict blood pressure control, mainly via blockade of the renin-angiotensin system (RAS). Attention has been drawn to additional beneficial effects of oral hypoglycemic drugs and fibrates on other aspects of diabetic nephropathy. On the other hand, antiproteinuric effects of RAS combination therapy do not seem to enhance the prevention of renal disease progression, and it has been associated with an increased rate of serious adverse events. Novel agents, such as bardoxolone methyl, pentoxifylline, inhibitors of protein kinase C (PKC), sulodexide, pirfenidone, endothelin receptor antagonists, vitamin D supplements, and phosphate binders have been associated with controversial outcomes or significant side effects. Although new insights into the pathogenetic mechanisms have opened new horizons towards novel interventions, there is still a long way to go in the field of DN research. The aim of this review is to highlight the recent progress made in the field of diabetes management based on the existing evidence. The article also discusses novel targets of therapy, with a special focus on the major pathophysiologic mechanisms implicated in the initiation and progression of diabetic nephropathy.

Horizon 2020 in Diabetic Kidney Disease: The Clinical Trial Pipeline for Add-On Therapies on Top of Renin Angiotensin System Blockade

Diabetic kidney disease is the most frequent cause of end-stage renal disease. This implies failure of current therapeutic approaches based on renin-angiotensin system (RAS) blockade. Recent phase 3 clinical trials of paricalcitol in early diabetic kidney disease and bardoxolone methyl in advanced diabetic kidney disease failed to meet the primary endpoint or terminated on safety concerns, respectively. However, various novel strategies are undergoing phase 2 and 3 randomized controlled trials targeting inflammation, fibrosis and signaling pathways. Among agents currently undergoing trials that may modify the clinical practice on top of RAS blockade in a 5-year horizon, anti-inflammatory agents currently hold the most promise while anti-fibrotic agents have so far disappointed. Pentoxifylline, an anti-inflammatory agent already in clinical use, was recently reported to delay estimated glomerular filtration rate (eGFR) loss in chronic kidney disease (CKD) stage 3–4 diabetic kidney disease when associated with RAS blockade and promising phase 2 data are available for the pentoxifylline derivative CTP-499. Among agents targeting chemokines or chemokine receptors, the oral small molecule C-C chemokine receptor type 2 (CCR2) inhibitor CCX140 decreased albuminuria and eGFR loss in phase 2 trials. A dose-finding trial of the anti-IL-1β antibody gevokizumab in diabetic kidney disease will start in 2015. However, clinical development is most advanced for the endothelin receptor A blocker atrasentan, which is undergoing a phase 3 trial with a primary outcome of preserving eGFR. The potential for success of these approaches and other pipeline agents is discussed in detail.

Diabetic Kidney Disease: Pathophysiology and Therapeutic Targets

Diabetes is a worldwide epidemic that has led to a rise in diabetic kidney disease (DKD). Over the past two decades, there has been significant clarification of the various pathways implicated in the pathogenesis of DKD. Nonetheless, very little has changed in the way clinicians manage patients with this disorder. Indeed, treatment is primarily centered on controlling hyperglycemia and hypertension and inhibiting the renin-angiotensin system. The purpose of this review is to describe the current understanding of how the hemodynamic, metabolic, inflammatory, and alternative pathways are all entangled in pathogenesis of DKD and detail the various therapeutic targets that may one day play a role in quelling this epidemic.

Present and future in the treatment of diabetic kidney disease

Diabetic kidney disease is the leading cause of end-stage renal disease. Albuminuria is recognized as the most important prognostic factor for chronic kidney disease progression. For this reason, blockade of renin-angiotensin system remains the main recommended strategy, with either angiotensin converting enzyme inhibitors or angiotensin II receptor blockers. However, other antiproteinuric treatments have begun to be studied, such as direct renin inhibitors or aldosterone blockers. Beyond antiproteinuric treatments, other drugs such as pentoxifylline or bardoxolone have yielded conflicting results. Finally, alternative pathogenic pathways are being explored, and emerging therapies including antifibrotic agents, endothelin receptor antagonists, or transcription factors show promising results. The aim of this review is to explain the advances in newer agents to treat diabetic kidney disease, along with the background of the renin-angiotensin system blockade.

Nephroprotective effect of heparanase in experimental nephrotic syndrome

BACKGROUND

Heparanase, an endoglycosidase that cleaves heparan sulfate (HS), is involved in various biologic processes. Recently, an association between heparanase and glomerular injury was suggested. The present study examines the involvement of heparanase in the pathogenesis of Adriamycin-induced nephrotic syndrome (ADR-NS) in a mouse model.

METHODS

BALB/c wild-type (wt) mice and heparanase overexpressing transgenic mice (hpa-TG) were tail-vein injected with either Adriamycin (ADR, 10 mg/kg) or vehicle. Albuminuria was investigated at days 0, 7, and 14 thereafter. Mice were sacrificed at day 15, and kidneys were harvested for various analyses: structure and ultrastructure alterations, podocyte proteins expression, and heparanase enzymatic activity.

RESULTS

ADR-injected wt mice developed severe albuminuria, while ADR-hpa-TG mice showed only a mild elevation in urinary albumin excretion. In parallel, light microscopy of stained cross sections of kidneys from ADR-injected wt mice, but not hpa-TG mice, showed mild to severe glomerular and tubular damage. Western blot and immunofluorescence analyses revealed significant reduction in nephrin and podocin protein expression in ADR-wt mice, but not in ADR-hpa-TG mice. These results were substantiated by electron-microscopy findings showing massive foot process effacement in injected ADR-wt mice, in contrast to largely preserved integrity of podocyte architecture in ADR-hpa-TG mice.

CONCLUSIONS

Our results suggest that heparanase may play a nephroprotective role in ADR-NS, most likely independently of HS degradation. Moreover, hpa-TG mice comprise an invaluable in vivo platform to investigate the interplay between heparanase and glomerular injury.