Advanced glycation end-products induce heparanase expression in endothelial cells by the receptor for advanced glycation end products and through activation of the FOXO4 transcription factor

High salt intake and HIV infection on endothelial glycocalyx shedding in salt-sensitive hypertension

The endothelial glycocalyx is closely associated with various physiological and pathophysiological events. Significant modification of the endothelial glycocalyx is an early process in the pathogenesis of cardiovascular disease. High dietary salt and HIV infection damages the endothelial glycocalyx causing endothelial dysfunction and increasing the risk for salt-sensitive hypertension and cardiovascular disease. The two factors, HIV infection and dietary salt are critical independent predictors of hypertension and cardiovascular disease and often synergize to exacerbate and accelerate disease pathogenesis. Salt-sensitive hypertension is more common among people living with HIV and is associated with risk for cardiovascular disease, stroke, heart attack and even death. However, the underlying mechanisms linking endothelial glycocalyx damage to dietary salt and HIV infection are lacking. Yet, both HIV infection/treatment and dietary salt are closely linked to endothelial glycocalyx damage and development of salt-sensitive hypertension. Moreover, the majority of individuals globally, consume more salt than is recommended and the burden of HIV especially in sub-Sahara Africa is disproportionately high. In this review, we have discussed the missing link between high salt and endothelial glycocalyx shedding in the pathogenesis of salt-sensitive hypertension. We have further elaborated the role played by HIV infection and treatment in modifying endothelial glycocalyx integrity to contribute to the development of hypertension and cardiovascular disease.

Heparanase as active player in endothelial glycocalyx remodeling

The surface of all animal cells is coated with a layer of carbohydrates linked in various ways to the outer side of the plasma membrane. These carbohydrates are mainly bound to proteins in the form of glycoproteins and proteoglycans and together with the glycolipids constitute the so-called glycocalyx. In particular, the endothelial glycocalyx that covers the luminal layer of the endothelium is composed of glycosaminoglycans (heparan sulphate -HS and hyaluronic acid -HA), proteoglycans (syndecans and glypicans) and adsorbed plasma proteins. Thanks to its ability to absorb water, this structure contributes to making the surface of the vessels slippery but at the same time acts by modulating the mechano-transduction of the vessels, the vascular permeability and the adhesion of leukocytes in thus regulating several physiological and pathological events. Among the various enzymes involved in the degradation of the glycocalyx, heparanase (HPSE) has been shown to be particularly involved. This enzyme is responsible for the cutting of heparan sulfate (HS) chains at the level of the proteoglycans of the endothelial glycocalyx whose dysfunction appears to have a role in organ fibrosis, sepsis and viral infection. In this mini-review, we describe the mechanisms by which HPSE contributes to glycocalyx remodeling and then examine the role of glycocalyx degradation in the development of pathological conditions and pharmacological strategies to preserve glycocalyx during disease pathogenesis.

Metformin in cardiovascular diabetology: a focused review of its impact on endothelial function

As a first-line treatment for diabetes, the insulin-sensitizing biguanide, metformin, regulates glucose levels and positively affects cardiovascular function in patients with diabetes and cardiovascular complications. Endothelial dysfunction (ED) represents the primary pathological change of multiple vascular diseases, because it causes decreased arterial plasticity, increased vascular resistance, reduced tissue perfusion and atherosclerosis. Caused by “biochemical injury”, ED is also an independent predictor of cardiovascular events. Accumulating evidence shows that metformin improves ED through liver kinase B1 (LKB1)/5'-adenosine monophosphat-activated protein kinase (AMPK) and AMPK-independent targets, including nuclear factor-kappa B (NF-κB), phosphatidylinositol 3 kinase-protein kinase B (PI3K-Akt), endothelial nitric oxide synthase (eNOS), sirtuin 1 (SIRT1), forkhead box O1 (FOXO1), krüppel-like factor 4 (KLF4) and krüppel-like factor 2 (KLF2). Evaluating the effects of metformin on endothelial cell functions would facilitate our understanding of the therapeutic potential of metformin in cardiovascular diabetology (including diabetes and its cardiovascular complications). This article reviews the physiological and pathological functions of endothelial cells and the intact endothelium, reviews the latest research of metformin in the treatment of diabetes and related cardiovascular complications, and focuses on the mechanism of action of metformin in regulating endothelial cell functions.

The Heparanase Regulatory Network in Health and Disease

The extracellular matrix (ECM) is a structural framework that has many important physiological functions which include maintaining tissue structure and integrity, serving as a barrier to invading pathogens, and acting as a reservoir for bioactive molecules. This cellular scaffold is made up of various types of macromolecules including heparan sulfate proteoglycans (HSPGs). HSPGs comprise a protein core linked to the complex glycosaminoglycan heparan sulfate (HS), the remodeling of which is important for many physiological processes such as wound healing as well as pathological processes including cancer metastasis. Turnover of HS is tightly regulated by a single enzyme capable of cleaving HS side chains: heparanase. Heparanase upregulation has been identified in many inflammatory diseases including atherosclerosis, fibrosis, and cancer, where it has been shown to play multiple roles in processes such as epithelial-mesenchymal transition, angiogenesis, and cancer metastasis. Heparanase expression and activity are tightly regulated. Understanding the regulation of heparanase and its downstream targets is attractive for the development of treatments for these diseases. This review provides a comprehensive overview of the regulators of heparanase as well as the enzyme's downstream gene and protein targets, and implications for the development of new therapeutic strategies.

Rethinking Fragility Fractures in Type 2 Diabetes: The Link between Hyperinsulinaemia and Osteofragilitas

Patients with type 2 diabetes mellitus (T2DM) and/or cardiovascular disease (CVD), conditions of hyperinsulinaemia, have lower levels of osteocalcin and bone remodelling, and increased rates of fragility fractures. Unlike osteoporosis with lower bone mineral density (BMD), T2DM bone fragility "hyperinsulinaemia-osteofragilitas" phenotype presents with normal to increased BMD. Hyperinsulinaemia and insulin resistance positively associate with increased BMD and fragility fractures. Hyperinsulinaemia enforces glucose fuelling, which decreases NAD+-dependent antioxidant activity. This increases reactive oxygen species and mitochondrial fission, and decreases oxidative phosphorylation high-energy production capacity, required for osteoblasto/cytogenesis. Osteocytes directly mineralise and resorb bone, and inhibit mineralisation of their lacunocanalicular space via pyrophosphate. Hyperinsulinaemia decreases vitamin D availability via adipocyte sequestration, reducing dendrite connectivity, and compromising osteocyte viability. Decreased bone remodelling and micropetrosis ensues. Trapped/entombed magnesium within micropetrosis fossilisation spaces propagates magnesium deficiency (MgD), potentiating hyperinsulinaemia and decreases vitamin D transport. Vitamin D deficiency reduces osteocalcin synthesis and favours osteocyte apoptosis. Carbohydrate restriction/fasting/ketosis increases beta-oxidation, ketolysis, NAD+-dependent antioxidant activity, osteocyte viability and osteocalcin, and decreases excess insulin exposure. Osteocalcin is required for hydroxyapatite alignment, conferring bone structural integrity, decreasing fracture risk and improving metabolic/endocrine homeodynamics. Patients presenting with fracture and normal BMD should be investigated for T2DM and hyperinsulinaemia.

Heparan Sulfate Proteoglycans in Diabetes

Diabetes is a complex disorder responsible for the mortality and morbidity of millions of individuals worldwide. Although many approaches have been used to understand and treat diabetes, the role of proteoglycans, in particular heparan sulfate proteoglycans (HSPGs), has only recently received attention. The HSPGs are heterogeneous, highly negatively charged, and are found in all cells primarily attached to the plasma membrane or present in the extracellular matrix (ECM). HSPGs are involved in development, cell migration, signal transduction, hemostasis, inflammation, and antiviral activity, and regulate cytokines, chemokines, growth factors, and enzymes. Hyperglycemia, accompanying diabetes, increases reactive oxygen species and upregulates the enzyme heparanase that degrades HSPGs or affects the synthesis of the HSPGs altering their structure. The modified HSPGs in the endothelium and ECM in the blood vessel wall contribute to the nephropathy, cardiovascular disease, and retinopathy seen in diabetes. Besides the blood vessel, other cells and tissues in the heart, kidney, and eye are affected by diabetes. Although not well understood, the adipose tissue, intestine, and brain also reveal HSPG changes associated with diabetes. Further, HSPGs are significantly involved in protecting the β cells of the pancreas from autoimmune destruction and could be a focus of prevention of type I diabetes. In some circumstances, HSPGs may contribute to the pathology of the disease. Understanding the role of HSPGs and how they are modified by diabetes may lead to new treatments as well as preventative measures to reduce the morbidity and mortality associated with this complex condition.

Endothelial Glycocalyx as a Regulator of Fibrotic Processes

The endothelial glycocalyx, the gel layer covering the endothelium, is composed of glycosaminoglycans, proteoglycans, and adsorbed plasma proteins. This structure modulates vessels’ mechanotransduction, vascular permeability, and leukocyte adhesion. Thus, it regulates several physiological and pathological events. In the present review, we described the mechanisms that disturb glycocalyx stability such as reactive oxygen species, matrix metalloproteinases, and heparanase. We then focused our attention on the role of glycocalyx degradation in the induction of profibrotic events and on the possible pharmacological strategies to preserve this delicate structure.

Dichotomic role of heparanase in a murine model of metabolic syndrome

Heparanase is the predominant enzyme that cleaves heparan sulfate, the main polysaccharide in the extracellular matrix. While the role of heparanase in sustaining the pathology of autoimmune diabetes is well documented, its association with metabolic syndrome/type 2 diabetes attracted less attention. Our research was undertaken to elucidate the significance of heparanase in impaired glucose metabolism in metabolic syndrome and early type 2 diabetes. Here, we report that heparanase exerts opposite effects in insulin-producing (i.e., islets) vs. insulin-target (i.e., skeletal muscle) compartments, sustaining or hampering proper regulation of glucose homeostasis depending on the site of action. We observed that the enzyme promotes macrophage infiltration into islets in a murine model of metabolic syndrome, and fosters β-cell-damaging properties of macrophages activated in vitro by components of diabetogenic/obese milieu (i.e., fatty acids). On the other hand, in skeletal muscle (prototypic insulin-target tissue), heparanase is essential to ensure insulin sensitivity. Thus, despite a deleterious effect of heparanase on macrophage infiltration in islets, the enzyme appears to have beneficial role in glucose homeostasis in metabolic syndrome. The dichotomic action of the enzyme in the maintenance of glycemic control should be taken into account when considering heparanase-targeting strategies for the treatment of diabetes.

Inhibition of heparanase protects against pancreatic beta cell death in streptozotocin-induced diabetic mice via reducing intra-islet inflammatory cell infiltration

BACKGROUND AND PURPOSE

Intra-islet heparan sulfate (HS) plays an important role in the maintenance of pancreatic islet function. The aim of this study was to investigate the effect mechanism of HS loss on the functioning of islets in diabetic mice.

EXPERIMENTAL APPROACH

The hypoglycaemic effect of a heparanase inhibitor, OGT2115, was tested in a streptozotocin-induced diabetic mouse model. The islets in pancreatic sections were also stained to reveal their morphology. An insulinoma cell line (MIN6) and primary isolated murine islets were used to investigate the effect of OGT2115 in vitro.

KEY RESULTS

Intra-islet HS was clearly lost in streptozotocin-induced diabetic mice due to the increased heparanase expression in damaged islets. OGT2115 prevented intra-islet HS loss and improved the glucose profile and insulin secretion in streptozotocin-treated mice. The apoptosis of pancreatic beta cells and the infiltration of mononuclear macrophages, CD4- and CD8-positive T-cells in islets was reduced by OGT2115 in streptozotocin-treated mice, but OGT2115 did not alter the direct streptozotocin-induced damage in vitro. The expression of heparanase was increased in high glucose-treated isolated islets but not in response to direct streptozotocin stimulation. Further experiments showed that high glucose stimuli could decreased expression of PPARγ in cultured islets, thereby relieving the PPARγ-induced inhibition of heparanase gene expression.

CONCLUSION AND IMPLICATIONS

Hyperglycaemia could cause intra-islet HS loss by elevating the expression of heparanase, thereby aggravating inflammatory cell infiltration and islet damage. Inhibition of heparanase might provide benefit for pancreatic beta cell protection in Type 1 diabetes.

Chemical constituents, clinical efficacy and molecular mechanisms of the ethanol extract of Abelmoschus manihot flowers in treatment of kidney diseases

Abelmoschus manihot, also called as “Huangkui” in Chinese, is an annual flowering herb plant in the family of Malvaceae. As a traditional Chinese medicine, the ethanol extract of the flower in Abelmoschus manihot is made as Huangkui capsule and has been used for medication of the patients with kidney diseases. Its efficacy in clinical symptoms is mainly improving renal function and reducing proteinuria among the patients with chronic kidney disease, diabetic kidney disease or IgA nephropathy. The possible mechanism of Huangkui capsule treatment in kidney diseases may include reducing inflammation and anti‐oxidative stress, improving immune response, protecting renal tubular epithelial cells, ameliorating podocyte apoptosis, glomerulosclerosis and mesangial proliferation, as well as inhibiting renal fibrosis. In this review, we first described chemical constituents and pharmacokinetic characteristics in ethanol extract of the flower of Abelmoschus manihot. We then summarized the clinical and epidemiological relevancies of kidney diseases particularly in the mainland of China and discussed the possible molecular mechanisms of Huangkui capsule in the treatment of kidney diseases. Finally, we prospected further research on cellular and molecular mechanisms and application of this Chinese natural medicine in kidney diseases.

Impact of Heparanse on Organ Fibrosis

Organ fibrosis is defined as a deregulated wound-healing process characterized by a progressive accumulation of fibrous tissue and by reduced remodeling that can lead to the loss of functionality of the affected organ. This pathological process is quite common in several parenchymal organs such as kidneys, liver, and lungs and represents a real health emergency in developed western countries since a real anti-fibrotic therapy is not yet available in most cases. Heparanase (HPSE), which is the enzyme that cuts off the side chains of heparan sulfate (HS) proteoglycan, appears to be involved in the aetiopathogenesis of fibrosis in all these organs, even if with different mechanisms. Here we discuss how the interplay between HPSE and components of the immune and inflammatory responses can activate recruitment, proliferation, and activation of myofibroblasts which represent the main cell type responsible for the deposition of fibrous matrix. Finally, bearing in mind that once the activity of HPSE is inhibited no other molecule is able to perform the same function, it is desirable that this enzyme could prove to be a suitable pharmacological target in anti-fibrotic therapy.

Regulation of Heparanase in Diabetes-Associated Pancreatic Carcinoma

While at least six types of cancer have been associated with diabetes, pancreatic ductal adenocarcinoma (PDAC) and diabetes exhibit a unique bidirectional relationship. Recent reports indicate that majority of PDAC patients display hyperglycemia, and ~50% have concurrent diabetes. In turn, hyperglycemic/diabetic state in PDAC patients fosters enhanced growth and dissemination of the tumor. Heparanase enzyme (the sole mammalian endoglycosidase degrading glycosaminoglycan heparan sulfate) is tightly implicated in PDAC progression, aggressiveness, and therapy resistance. Overexpression of heparanase is a characteristic feature of PDAC, correlating with poor prognosis. However, given the lack of heparanase expression in normal pancreatic tissue, the regulatory mechanisms responsible for induction of the enzyme in PDAC have remained largely unknown. Previously reported inducibility of heparanase gene by diabetic milieu components in several non-cancerous cell types prompted us to hypothesize that in the setting of diabetes-associated PDAC, hyperglycemic state may induce heparanase overexpression. Here, utilizing a mouse model of diet-induced metabolic syndrome/diabetes, we found accelerated PDAC progression in hyperglycemic mice, occurring along with induction of heparanase in PDAC. In vitro, we demonstrated that advanced glycation end-products (AGE), which are largely thought as oxidative derivatives resulting from chronic hyperglycemia, and the receptor for AGE (RAGE) are responsible for heparanase induction in PDAC cells. These findings underscore the new mechanism underlying preferential expression of heparanase in pancreatic cancer. Moreover, taken together with the well-established causal role of the enzyme in PDAC progression, our findings indicate that heparanase may sustain (at least in part) reciprocal causality between diabetes and pancreatic tumorigenesis.

Plasma heparanase is associated with blood glucose levels but not urinary microalbumin excretion in type 2 diabetic nephropathy at the early stage

Aim: To explore the possible correlations between plasma heparanase and albuminuria, glucose and lipid metabolism in the type 2 diabetic nephropathy patients at the early stage.

Methods: One hundred and forty patients with type 2 diabetic nephropathy at early stage were recruited into the study. Plasma heparanase and the characterized advanced glycation end products (AGEs), carboxymethyllysine (CML) were measured by enzyme-linked immunosorbent assay.

Results: Plasma heparanase was positively associated with fasting blood glucose (R = 0.24, p = .01) while heparanase was not significantly correlated with the urinary microalbumin to creatinine ratio (urinary mAlb/Cr) (R = 0.05, p = .58) and CML (R = 0.16, p = .26). On stepwise linear regression analysis, fasting blood glucose was the main independent determinants of plasma heparanase concentration.

Conclusion: Plasma heparanase is not significantly associated with urinary mAlb/Cr while it is correlated positively with blood glucose levels in the early stage of diabetic nephropathy. Plasma heparnase might be regarded as a marker for vascular endothelial cells injury in diabetic patients.

The receptor for advanced glycation endproducts mediates podocyte heparanase expression through NF-κB signaling pathway

Heparanase degrades heparan sulfate in glomerular basement membrane (GBM) and plays an important role in diabetic nephropathy (DN). However, its regulating mechanisms remain to be deciphered. Our present study showed that the major advanced glycation endproducts (AGEs), CML-BSA, significantly increased heparanase expression in cultured podocytes and the effect was blocked by the receptor for advanced glycation endproducts (RAGE) knockdown, antibody and antagonist. In addition, NF-κB p65 phosphorylation was elevated and the increased heparanase expression and secretion upon CML-BSA could be attenuated by NF-κB inhibitor PDTC. Mechanistically, CML-BSA activated heparanase promoter through p65 directly binding to its promoter. Furthermore, the in vivo study showed that serum and renal cortex AGEs levels, glomerular p65 phosphorylation and heparanase expression were significantly increased in DN mice. Taken together, our data suggest that AGEs and RAGE interaction increases podocyte heparanase expression by activating NF-κB signal pathway, which is involved in GBM damages of DN.

Heparanase augments insulin receptor signaling in breast carcinoma

Recently, growing interest in the potential link between metabolic disorders (i.e., diabetes, obesity, metabolic syndrome) and breast cancer has mounted, including studies which indicate that diabetic/hyperinsulinemic women have a significantly higher risk of bearing breast tumors that are more aggressive and associated with higher death rates. Insulin signaling is regarded as a major contributor to this phenomenon; much less is known about the role of heparan sulfate-degrading enzyme heparanase in the link between metabolic disorders and cancer.In the present study we analyzed clinical samples of breast carcinoma derived from diabetic/non-diabetic patients, and investigated effects of heparanase on insulin signaling in breast carcinoma cell lines, as well as insulin-driven growth of breast tumor cells.We demonstrate that heparanase activity leads to enhanced insulin signaling and activation of downstream tumor-promoting pathways in breast carcinoma cells. In agreement, heparanase enhances insulin-induced proliferation of breast tumor cells in vitro. Moreover, analyzing clinical data from diabetic breast carcinoma patients, we found that concurrent presence of both diabetic state and heparanase in tumor tissue (as opposed to either condition alone) was associated with more aggressive phenotype of breast tumors in the patient cohort analyzed in our study (two-sided Fisher's exact test; p=0.04). Our findings highlight the emerging role of heparanase in powering effect of hyperinsulinemic state on breast tumorigenesis and imply that heparanase targeting, which is now under intensive development/clinical testing, could be particularly efficient in a growing fraction of breast carcinoma patients suffering from metabolic disorders.

Protein glycation - Between tissue aging and protection

Non-enzymatic formation of advanced glycation endproducts (AGEs) is associated with degenerative diseases. Chronic accumulation of AGEs with age in tissues especially in the extracellular matrix is well known and at least in part responsible for e.g., collagen crosslinking, tissue stiffening and thus induction of high blood pressure or diastolic heart failure. Binding of soluble AGEs to the receptor for AGEs, RAGE, induces an inflammatory response whereas the soluble form of RAGE (sRAGE) can inhibit inflammatory tissue injury like arteriosclerosis in mouse models. However, there are a number of indications that AGEs have protective effects as well. AGEs may inhibit lung tumor growth, glyoxal induced AGE modification of human heart muscle can reduce an ischemia reperfusion injury and AGEs from nutrition can reduce ROS induced cell damage.

CONCLUSIONS

In summary, this indicates that protein glycation behaves like a double-edged sword. It induces tissue aging and degenerative diseases on the one hand, on the other hand, may also have protective effects, indicating a hormetic response.

Advanced glycation endproducts in food and their effects on health

Advanced glycation endproducts (AGEs) form by Maillard-reactions after initial binding of aldehydes with amines or amides in heated foods or in living organisms. The mechanisms of formation may include ionic as well as oxidative and radical pathways. The reactions may proceed within proteins to form high-molecular weight (HMW) AGEs or among small molecules to form low-molecular weight (LMW) AGEs. All free amino acids form AGEs, but lysine or arginine side chains dominate AGE formation within proteins. The analysis of AGEs in foods and body fluids is most often performed by ELISA or LC-MS; however, none of the methodologies cover all HMW and LMW AGEs. Most research is, therefore, carried out using 'representative' AGE compounds, most often N(ε)-carboxymethyl-lysine (CML). Only LMW AGEs, including peptide-bound forms, and carbonyls may be absorbed from the gut and contribute to the body burden of AGEs. Some AGEs interact with specific pro- or anti-inflammatory receptors. Most studies on the biological effects of AGEs have been carried out by administering heated foods. The pro-inflammatory and deteriorating biological effects of AGEs in these studies, therefore, need further confirmation. The current review points out several research needs in order to address important questions on AGEs in foods and health.

Heparanase induced by advanced glycation end products (AGEs) promotes macrophage migration involving RAGE and PI3K/AKT pathway

Background

Advanced glycation end products (AGEs), inflammatory-associated macrophage migration and accumulation are crucial for initiation and progression of diabetic vascular complication. Enzymatic activity of heparanase (HPA) is implicated strongly in dissemination of metastatic tumor cells and cells of the immune system. In addition, HPA enhances the phosphorylation of selected signaling molecules including AKT pathway independent of enzymatic activity. However, virtually nothing is presently known the role of HPA during macrophage migration exposed to AGEs involving signal pathway.

Methods

These studies were carried out in Ana-1 macrophages. Macrophage viability was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays. HPA and AKT protein expression in macrophages are analysed by Western blotting and HPA mRNA expression by real time quantitative RT-PCR. Release of HPA was determined by ELISA. Macrophage migration was assessed by Transwell assays.

Results

HPA protein and mRNA were found to be increased significantly in AGEs-treated macrophages. Pretreatment with anti-HPA antibody which recognizes the nonenzymatic terminal of HPA prevented AGEs-induced AKT phosphorylation and macrophage migration. LY294002 (PI3k/AKT inhibitor) inhibited AGEs-induced macrophage migration. Furthermore, pretreatment with anti-receptor for advanced glycation end products (RAGE) antibody attenuated AGEs-induced HPA expression, AKT phosphorylation and macrophage migration.

Conclusions

These data indicate that AGEs-induced macrophage migration is dependent on HPA involving RAGE-HPA-PI3K/AKT pathway. The nonenzymatic activity of HPA may play a key role in AGEs-induced macrophage migration associated with inflammation in diabetic vascular complication.

Regulation of heparanase by albumin and advanced glycation end products in proximal tubular cells

Diabetic nephropathy is one of the main causes of end-stage renal disease, in which the development of tubular damage depends on factors such as high glucose levels, albuminuria and advanced glycation end-product. In this study, we analyzed the involvement of heparanase, a heparan sulfate glycosidase, in the homeostasis of proximal tubular epithelial cells in the diabetic milieu. In vitro studies were performed on a wild-type and stably heparanase-silenced adult tubular line (HK2) and HEK293. Gene and protein expression analyses were performed in the presence and absence of diabetic mediators. Albumin and advanced glycation end-product, but not high glucose levels, increased heparanase expression in adult tubular cells via the AKT/PI3K signaling pathway. This over-expression of heparanase is then responsible for heparan sulfate reduction via its endoglycosidase activity and its capacity to regulate the heparan sulfate-proteoglycans core protein. In fact, heparanase regulates the gene expression of syndecan-1, the most abundant heparan sulfate-proteoglycans in tubular cells. We showed that heparanase is a target gene of the diabetic nephropathy mediators albumin and advanced glycation end-product, so it may be relevant to the progression of diabetic nephropathy. It could take part in several processes, e.g. extracellular-matrix remodeling and cell-cell crosstalk, via its heparan sulfate endoglycosidase activity and capacity to regulate the expression of the heparan sulfate-proteoglycan syndecan-1.