Investigation of inhibitory effect of sulfated chitosan oligomer on human heparanase enzyme: in silico and in vitro studies

Deaths from cancer are widespread worldwide and the numbers continue to increase day by day. During the disease progression of cancer in cells, many of its metabolic activities change. Increased heparanase enzyme release is just one example. Following heparanase enzyme activity, many molecules interact with the remodeling of glycosaminoglycan structures, which triggers the release of different enzymes, cytokines, and growth factors, including fibroblast growth factors (FGF1 and FGF2), vascular endothelial growth factor (VEGF), hepatocyte growth factor, transforming growth factor β and platelet-derived growth factor. These are the most important factors in metastasis due to the formation of new vascular structures caused by those elements. To reduce tumor growth and metastasis, various drugs have been designed by modifying chitosan and its derivatives. In this study, we used chitosan oligomer (A), sulfated chitosan oligomer (ShCsO) (B), heparin (C), phosphate monomer (D1) of PI-88 and sulfate monomer (D2) of PI-88 as heparanase inhibitors. We modified the chitosan oligomer with chlorosulfonic acid to synthesize ShCsO to investigate its inhibitory effects on human serum heparanase. Also examined were molecular docking; molecular dynamics (MD); adsorption, distribution, metabolism, elimination and toxicity (ADMET); and target prediction. ShCsO decreased enzyme activity at a concentration of 0.0001 mg/mL. The docking scores of A, B and C from in silico studies were -6.254, -6.936 and -6.980 kcal/mol, respectively, and the scores for the two different PI-88 monomers were -5.741 and -5.824 kcal/mol. These results show that ShCsO may be a potential drug candidate for treating cancer.Communicated by Ramaswamy H. Sarma.

Proteomic analyses of urinary exosomes identify novel potential biomarkers for early diagnosis of sickle cell nephropathy, a sex-based study

Sickle cell nephropathy (SCN) is a leading cause of morbidity and mortality in sickle cell disease (SCD). Early intervention is crucial for mitigating its effects. However, current diagnostic methods rely on generic tests and may not detect SCN until irreversible renal damage occurs. Therefore, specific biomarkers for early diagnosis of SCN are needed. Urinary exosomes, membrane-bound vesicles secreted by renal podocytes and epithelial cells, contain both common and cell type-specific membrane and cytosolic proteins, reflecting the physiologic and pathophysiologic states of the kidney. Using proteomics, we analyzed the proteomes of urinary exosomes from humanized SCD mice at 2 months (without albuminuria) and 4 months (with albuminuria) of age. Excretion of 164 proteins were significantly increased and 176 proteins was significantly decreased in the exosomes when mice developed albuminuria. Based on the relevance to SCD, chronic kidney disease and Western blot confirmation in mice, we analyzed protein abundance of heparanase, cathepsin C, α2-macroglobulin and sarcoplasmic endoplasmic Ca2+ ATPase-3 (SERCA3) in the urinary exosomes and urine of 18 SCD subjects without albuminuria and 12 subjects with albuminuria using Western blot analyses. Both male and female subjects increased or tended to increase the excretion of these proteins in their urinary exosomes upon developing albuminuria, but female subjects demonstrated stronger correlations between the excretion of these proteins and urine albumin creatinine ratio (UACR) compared to male subjects. In contrast, exosomal excretion of Tamm-Horsfall protein, β-actin and SHP-1 was independent of albuminuria. These findings provide a foundation for a time-course study to determine whether increases in the levels of these proteins precede the onset of albuminuria in patients, which will help determine the potential of these proteins as biomarkers for early detection of SCN.

Heparanase inhibitor OGT 2115 induces prostate cancer cell apoptosis via the downregulation of MCL‑1

Heparanase (HPSE), an endo-β-D-glucuronidase, cleaves heparan sulfate and serves an important role in the tumor microenvironment and thus in tumorigenesis. HPSE is known to promote tumor cell evasion of apoptosis. However, the underlying mechanism of this requires further study. In the present study, the results demonstrated that myeloid cell leukemia-1 (MCL-1), an antiapoptotic protein, and HPSE were upregulated in prostate cancer tissues compared with adjacent normal tissues. In addition, the HPSE inhibitor, OGT 2115, inhibited PC-3 and DU-145 prostate cancer cell viability in a dose-dependent manner, with IC50 values of 20.2 and 97.2 µM, respectively. Furthermore, annexin V/PI double-staining assays demonstrated that OGT 2115 induced apoptosis in prostate cancer cells. OGT 2115 treatment markedly decreased MCL-1 protein expression levels, whereas RNA interference-mediated downregulation of MCL-1 and OGT 2115 drug treatment synergistically induced apoptosis in PC-3 and DU-145 cells. In vivo, OGT 2115 40 mg/kg (ig) significantly inhibited PC-3 cell xenograft growth in nude mice and increased the positive TUNEL staining rate of xenograft tissues. It was therefore hypothesized that MCL-1 was an important signaling molecule in OGT 2115-induced apoptosis. The results of the present study also demonstrated that the proteasome inhibitor, MG-132, markedly inhibited the downregulation of MCL-1 protein expression levels induced by OGT 2115. However, the protein synthesis inhibitor, cycloheximide, did not affect the role of OGT 2115 in regulating MCL-1. In summary, the results of the present study demonstrated that the proapoptotic activity of OGT 2115 was achieved by downregulating MCL-1.

A New Synthesized Dicarboxylated Oxy-Heparin Efficiently Attenuates Tumor Growth and Metastasis

Heparanase (Hpa1) is expressed by tumor cells and cells of the tumor microenvironment and functions to remodel the extracellular matrix (ECM) and regulate the bioavailability of ECM-bound factors that support tumor growth. Heparanase expression is upregulated in human carcinomas, sarcomas, and hematological malignancies, correlating with increased tumor metastasis, vascular density, and shorter postoperative survival of cancer patients, and encouraging the development of heparanase inhibitors as anti-cancer drugs. Among these are heparin/HS mimetics, the only heparanase-inhibiting compounds that are being evaluated in clinical trials. We have synthesized dicarboxylated oxy-heparins (DCoxHs) containing three carboxylate groups per split residue (DC-Hep). The resulting lead compound (termed XII) was upscaled, characterized, and examined for its effectiveness in tumor models. Potent anti-tumorigenic effects were obtained in models of pancreatic carcinoma, breast cancer, mesothelioma, and myeloma, yielding tumor growth inhibition (TGI) values ranging from 21 to 70% and extending the survival time of the mice. Of particular significance was the inhibition of spontaneous metastasis in an orthotopic model of breast carcinoma following resection of the primary tumor. It appears that apart from inhibition of heparanase enzymatic activity, compound XII reduces the levels of heparanase protein and inhibits its cellular uptake and activation. Heparanase-dependent and -independent effects of XII are being investigated. Collectively, our pre-clinical studies with compound XII strongly justify its examination in cancer patients.

Role of heparanase in pulmonary hypertension

Pulmonary hypertension (PH) is a pathophysiological condition of increased pulmonary circulation vascular resistance due to various reasons, which mainly leads to right heart dysfunction and even death, especially in critically ill patients. Although drug interventions have shown some efficacy in improving the hemodynamics of PH patients, the mortality rate remains high. Hence, the identification of new targets and treatment strategies for PH is imperative. Heparanase (HPA) is an enzyme that specifically cleaves the heparan sulfate (HS) side chains in the extracellular matrix, playing critical roles in inflammation and tumorigenesis. Recent studies have indicated a close association between HPA and PH, suggesting HPA as a potential therapeutic target. This review examines the involvement of HPA in PH pathogenesis, including its effects on endothelial cells, inflammation, and coagulation. Furthermore, HPA may serve as a biomarker for diagnosing PH, and the development of HPA inhibitors holds promise as a targeted therapy for PH treatment.

Role of heparanase in sepsis‑related acute kidney injury (Review)

Sepsis-related acute kidney injury (S-AKI) is a common and significant complication of sepsis in critically ill patients, which can often only be treated with antibiotics and medications that reduce S-AKI symptoms. The precise mechanism underlying the onset of S-AKI is still unclear, thus hindering the development of new strategies for its treatment. Therefore, it is necessary to explore the pathogenesis of S-AKI to identify biomarkers and therapeutic targets for its early diagnosis and treatment. Heparanase (HPA), the only known enzyme that cleaves the side chain of heparan sulfate, has been widely studied in relation to tumor metabolism, procoagulant activity, angiogenesis, inflammation and sepsis. It has been reported that HPA plays an important role in the progression of S-AKI. The aim of the present review was to provide an overview of the function of HPA in S-AKI and to summarize its underlying molecular mechanisms, including mediating inflammatory response, immune response, autophagy and exosome biogenesis. It is anticipated that emerging discoveries about HPA in S-AKI will support HPA as a potential biomarker and therapeutic target to combat S-AKI.

Tissue factor-heparanase complex: intracellular nonhemostatic effects

Background

Heparanase, known to be involved in angiogenesis, cancer progression, and inflammation, was shown to form a complex with tissue factor (TF) via its procoagulant domain and to enhance the hemostatic system.

Objectives

To reveal a potential role of heparanase procoagulant domain in nonhemostatic effects.

Methods

Effects of peptides 16 and 16AC derived from the heparanase procoagulant domain, discovered by our group, were studied using the XTT proliferation assay, western blot analysis, and immunostaining in vitro and a mouse wound-healing model.

Results

Procoagulant peptides induced increased proliferation, release of heparanase, and upregulation of heparanase, TF, tissue factor pathway inhibitor (TFPI), and TFPI-2 in U87, T47D, and MCF-7 tumor cell lines and in endothelial cells. These results were reversed by a peptide derived from TFPI-2 that inhibited the heparanse procoagulant domain-TF complex. Thrombin had a similar effect on tumor cell proliferation and heparanase release, although the impact of thrombin on cell proliferation was mediated by the heparanase procoagulant domain. A mouse model of full-thickness skin incision exhibited higher levels of heparanase, TF, TFPI, and TFPI-2 in the healing skin, mainly in the blood vessel wall and lumen in animals injected with the procoagulant peptides compared to controls. The cells transfected to overexpress full-length TF or TF devoid of the cytoplasmic domain demonstrated that the procoagulant domain conveyed intracellular signaling via TF.

Conclusion

Heparanase procoagulant domain induces nonhemostatic effects via TF. The finding that TF serves as a receptor to heparanase supports the close direct relation between the hemostatic system and cancer progression.

Heparanase-A single protein with multiple enzymatic and nonenzymatic functions

Heparanase (Hpa1) is expressed by tumor cells and cells of the tumor microenvironment and functions extracellularly to remodel the extracellular matrix (ECM) and regulate the bioavailability of ECM-bound factors, augmenting, among other effects, gene transcription, autophagy, exosome formation, and heparan sulfate (HS) turnover. Much of the impact of heparanase on tumor progression is related to its function in mediating tumor-host crosstalk, priming the tumor microenvironment to better support tumor growth, metastasis, and chemoresistance. The enzyme appears to fulfill some normal functions associated, for example, with vesicular traffic, lysosomal-based secretion, autophagy, HS turnover, and gene transcription. It activates cells of the innate immune system, promotes the formation of exosomes and autophagosomes, and stimulates signal transduction pathways via enzymatic and nonenzymatic activities. These effects dynamically impact multiple regulatory pathways that together drive tumor growth, dissemination, and drug resistance as well as inflammatory responses. The emerging premise is that heparanase expressed by tumor cells, immune cells, endothelial cells, and other cells of the tumor microenvironment is a key regulator of the aggressive phenotype of cancer, an important contributor to the poor outcome of cancer patients and a valid target for therapy. So far, however, antiheparanase-based therapy has not been implemented in the clinic. Unlike heparanase, heparanase-2 (Hpa2), a close homolog of heparanase (Hpa1), does not undergo proteolytic processing and hence lacks intrinsic HS-degrading activity, the hallmark of heparanase. Hpa2 retains the capacity to bind heparin/HS and exhibits an even higher affinity towards HS than heparanase, thus competing for HS binding and inhibiting heparanase enzymatic activity. It appears that Hpa2 functions as a natural inhibitor of Hpa1 regulates the expression of selected genes that maintain tissue hemostasis and normal function, and plays a protective role against cancer and inflammation, together emphasizing the significance of maintaining a proper balance between Hpa1 and Hpa2.

Investigating the Role of Heparanase in Breast Cancer Development Utilising the MMTV-PyMT Murine Model of Mammary Carcinoma

Breast cancer is the second most common human malignancy and is a major global health burden. Heparanase (HPSE) has been widely implicated in enhancing the development and progression of solid tumours, including breast cancer. In this study, the well-established spontaneous mammary tumour-developing MMTV-PyMT murine model was utilised to examine the role of HPSE in breast cancer establishment, progression, and metastasis. The use of HPSE-deficient MMTV-PyMT (MMTV-PyMTxHPSE^-/-) mice addressed the lack of genetic ablation models to investigate the role of HPSE in mammary tumours. It was demonstrated that even though HPSE regulated mammary tumour angiogenesis, mammary tumour progression and metastasis were HPSE-independent. Furthermore, there was no evidence of compensatory action by matrix metalloproteinases (MMPs) in response to the lack of HPSE expression in the mammary tumours. These findings suggest that HPSE may not play a significant role in the mammary tumour development of MMTV-PyMT animals. Collectively, these observations may have implications in the clinical setting of breast cancer and therapy using HPSE inhibitors.

A Screening Approach to Assess the Impact of Various Commercial Sources of Crude Marine λ-Carrageenan on the Production of Oligosaccharides with Anti-heparanase and Anti-migratory Activities

Oligosaccharides derived from λ-carrageenan (λ-COs) are gaining interest in the cancer field. They have been recently reported to regulate heparanase (HPSE) activity, a protumor enzyme involved in cancer cell migration and invasion, making them very promising molecules for new therapeutic applications. However, one of the specific features of commercial λ-carrageenan (λ-CAR) is that they are heterogeneous mixtures of different CAR families, and are named according to the thickening-purpose final-product viscosity which does not reflect the real composition. Consequently, this can limit their use in a clinical applications. To address this issue, six commercial λ-CARs were compared and differences in their physiochemical properties were analyzed and shown. Then, a H₂O₂-assisted depolymerization was applied to each commercial source, and number- and weight-averaged molar masses (M_n and M_w) and sulfation degree (DS) of the λ-COs produced over time were determined. By adjusting the depolymerization time for each product, almost comparable λ-CO formulations could be obtained in terms of molar masses and DS, which ranged within previously reported values suitable for antitumor properties. However, when the anti-HPSE activity of these new λ-COs was screened, small changes that could not be attributed only to their small length or DS changes between them were found, suggesting a role of other features, such as differences in the initial mixture composition. Further structural MS and NMR analysis revealed qualitative and semi-quantitative differences between the molecular species, especially in the proportion of the anti-HPSE λ-type, other CARs types and adjuvants, and it also showed that H₂O₂-based hydrolysis induced sugar degradation. Finally, when the effects of λ-COs were assessed in an in vitro migration cell-based model, they seemed more related to the proportion of other CAR types in the formulation than to their λ-type-dependent anti-HPSE activity.

Heparin, Heparan Sulphate and Sepsis: Potential New Options for Treatment

Sepsis is a life-threatening hyperreaction to infection in which excessive inflammatory and immune responses cause damage to host tissues and organs. The glycosaminoglycan heparan sulphate (HS) is a major component of the cell surface glycocalyx. Cell surface HS modulates several of the mechanisms involved in sepsis such as pathogen interactions with the host cell and neutrophil recruitment and is a target for the pro-inflammatory enzyme heparanase. Heparin, a close structural relative of HS, is used in medicine as a powerful anticoagulant and antithrombotic. Many studies have shown that heparin can influence the course of sepsis-related processes as a result of its structural similarity to HS, including its strong negative charge. The anticoagulant activity of heparin, however, limits its potential in treatment of inflammatory conditions by introducing the risk of bleeding and other adverse side-effects. As the anticoagulant potency of heparin is largely determined by a single well-defined structural feature, it has been possible to develop heparin derivatives and mimetic compounds with reduced anticoagulant activity. Such heparin mimetics may have potential for use as therapeutic agents in the context of sepsis.

Extracellular vesicles released during hypoxia transport heparanase and enhance macrophage migration, endothelial tube formation and cancer cell stemness

Heparanase is upregulated during the progression of most cancers and via its enzyme activity promotes extracellular matrix degradation, angiogenesis and cell migration. Heparanase expression is often associated with enhanced tumor aggressiveness and chemoresistance. We previously demonstrated that increased heparanase expression in tumor cells enhances secretion and alters the composition of tumor-released exosomes. In the present study, we discovered that extracellular vesicles (EVs) secreted by human multiple myeloma cells growing in hypoxic conditions exhibited elevated levels of heparanase cargo compared to EVs from cells growing in normoxic conditions. When macrophages (RAW 264.7 monocyte/macrophage-like cells) were exposed to EVs released by tumor cells growing in either hypoxic or normoxic conditions, macrophage migration and invasion was elevated by EVs from hypoxic conditions. The elevated invasion of macrophages was blocked by a monoclonal antibody that inhibits heparanase enzyme activity. Moreover, the heparanase-bearing EVs from hypoxic cells greatly enhanced endothelial cell tube formation consistent with the known role of heparanase in promoting angiogenesis. EVs from hypoxic tumor cells when compared with EVs from normoxic cells also enhanced cancer stemness properties of both CAG and RPMI 8226 human myeloma cells. Together these data indicate that under hypoxic conditions, tumor cells secrete EVs having an elevated level of heparanase as cargo. These EVs can act on both tumor and non-tumor cells, enhancing tumor progression and tumor cell stemness that likely supports chemoresistance and relapse of tumor.

Flow-Induced Secretion of Endothelial Heparanase Regulates Cardiac Lipoprotein Lipase and Changes Following Diabetes

Background Lipoprotein lipase (LPL)-derived fatty acid is a major source of energy for cardiac contraction. Synthesized in cardiomyocytes, LPL requires translocation to the vascular lumen for hydrolysis of lipoprotein triglyceride, an action mediated by endothelial cell (EC) release of heparanase. We determined whether flow-mediated biophysical forces can cause ECs to secrete heparanase and thus regulate cardiac metabolism. Methods and Results Isolated hearts were retrogradely perfused. Confluent rat aortic ECs were exposed to laminar flow using an orbital shaker. Cathepsin L activity was determined using gelatin-zymography. Diabetes was induced in rats with streptozotocin. Despite the abundance of enzymatically active heparanase in the heart, it was the enzymatically inactive, latent heparanase that was exceptionally responsive to flow-induced release. EC exposed to orbital rotation exhibited a similar pattern of heparanase secretion, an effect that was reproduced by activation of the mechanosensor, Piezo1. The laminar flow-mediated release of heparanase from EC required activation of both the purinergic receptor and protein kinase D, a kinase that assists in vesicular transport of proteins. Heparanase influenced cardiac metabolism by increasing cardiomyocyte LPL displacement along with subsequent replenishment. The flow-induced heparanase secretion was augmented following diabetes and could explain the increased heparin-releasable pool of LPL at the coronary lumen in these diabetic hearts. Conclusions ECs sense fluid shear-stress and communicate this information to subjacent cardiomyocytes with the help of heparanase. This flow-induced mechanosensing and its dynamic control of cardiac metabolism to generate ATP, using LPL-derived fatty acid, is exquisitely adapted to respond to disease conditions, like diabetes.

Opposing Roles of IGFBP-3 and Heparanase in Regulating A549 Lung Cancer Cell Survival

In this study, we examined the roles of heparanase and IGFBP-3 in regulating A549 and H1299 non-small-cell lung cancer (NSCLC) survival. We found that H1299 cells, known to be p53-null with no expression of IGFBP-3, had higher heparanase levels and activity and higher levels of heparan sulfate (HS) in the media compared to the media of A549 cells. Inhibiting heparanase activity or its expression using siRNA had no effect on the levels of IGFBP-3 in the media of A549 cells, reduced the levels of soluble HS fragments, and led to decreased interactions between IGFBP-3 and HS in the media. HS competed with HA for binding to IGFBP-3 or IGFBP-3 peptide (²¹⁵-KKGFYKKKQCRPSKGRKR-²³²) but not the mutant peptide (K228AR230A). HS abolished the cytotoxic effects of IGFBP-3 but not upon blocking HA-CD44 signaling with the anti-CD44 antibody (5F12). Blocking HA-CD44 signaling decreased the levels of heparanase in the media of both A549 and H1299 cell lines and increased p53 activity and the levels of IGFBP-3 in A549 cell media. Knockdown of p53 led to increased heparanase levels and reduced IGFBP-3 levels in A549 cell media while knockdown of IGFBP-3 in A549 cells blocked p53 activity and increased heparanase levels in the media.

Heparanase Increases Podocyte Survival and Autophagic Flux after Adriamycin-Induced Injury

The kidney glomerular filtration barrier (GFB) is enriched with heparan sulfate (HS) proteoglycans, which contribute to its permselectivity. The endoglycosidase heparanase cleaves HS and hence appears to be involved in the pathogenesis of kidney injury and glomerulonephritis. We have recently reported, nonetheless, that heparanase overexpression preserved glomerular structure and kidney function in an experimental model of Adriamycin-induced nephropathy. To elucidate mechanisms underlying heparanase function in podocytes-key GFB cells, we utilized a human podocyte cell line and transgenic mice overexpressing heparanase. Notably, podocytes overexpressing heparanase (H) demonstrated significantly higher survival rates and viability after exposure to Adriamycin or hydrogen peroxide, compared with mock-infected (V) podocytes. Immunofluorescence staining of kidney cryo-sections and cultured H and V podocytes as well as immunoblotting of proteins extracted from cultured cells, revealed that exposure to toxic injury resulted in a significant increase in autophagic flux in H podocytes, which was reversed by the heparanase inhibitor, Roneparstat (SST0001). Heparanase overexpression was also associated with substantial transcriptional upregulation of autophagy genes BCN1, ATG5, and ATG12, following Adriamycin treatment. Moreover, cleaved caspase-3 was attenuated in H podocytes exposed to Adriamycin, indicating lower apoptotic cell death in H vs. V podocytes. Collectively, these findings suggest that in podocytes, elevated levels of heparanase promote cytoprotection.

Heparin-Superparamagnetic Iron Oxide Nanoparticles for Theranostic Applications

In this study, superparamagnetic iron oxide nanoparticles (SPIONs) were engineered with an organic coating composed of low molecular weight heparin (LMWH) and bovine serum albumin (BSA), providing heparin-based nanoparticle systems (LMWH@SPIONs). The purpose was to merge the properties of the heparin skeleton and an inorganic core to build up a targeted theranostic nanosystem, which was eventually enhanced by loading a chemotherapeutic agent. Iron oxide cores were prepared via the co-precipitation of iron salts in an alkaline environment and oleic acid (OA) capping. Dopamine (DA) was covalently linked to BSA and LMWH by amide linkages via carbodiimide coupling. The following ligand exchange reaction between the DA-BSA/DA-LMWH and OA was conducted in a biphasic system composed of water and hexane, affording LMWH@SPIONs stabilized in water by polystyrene sulfonate (PSS). Their size and morphology were investigated via dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The LMWH@SPIONs’ cytotoxicity was tested, showing marginal or no toxicity for samples prepared with PSS at concentrations of 50 µg/mL. Their inhibitory activity on the heparanase enzyme was measured, showing an effective inhibition at concentrations comparable to G4000 (N-desulfo-N-acetyl heparin, a non-anticoagulant and antiheparanase heparin derivative; Roneparstat). The LMWH@SPION encapsulation of paclitaxel (PTX) enhanced the antitumor effect of this chemotherapeutic on breast cancer cells, likely due to an improved internalization of the nanoformulated drug with respect to the free molecule. Lastly, time-domain NMR (TD-NMR) experiments were conducted on LMWH@SPIONs obtaining relaxivity values within the same order of magnitude as currently used commercial contrast agents.

Osteochondroma formation is independent of heparanase expression as revealed in a mouse model of hereditary multiple exostoses

Hereditary multiple exostoses (HME) is a rare, pediatric disorder characterized by osteochondromas that form along growth plates and provoke significant musculoskeletal problems. HME is caused by mutations in heparan sulfate (HS)-synthesizing enzymes EXT1 or EXT2. Seemingly paradoxically, osteochondromas were found to contain excessive extracellular heparanase (Hpse) that could further reduce HS levels and exacerbate pathogenesis. To test Hpse roles, we asked whether its ablation would protect against osteochondroma formation in a conditional HME model consisting of mice bearing floxed Ext1 alleles in Agr-CreER background (Ext1f/f ;Agr-CreER mice). Mice were crossed with a new global Hpse-null (Hpse-/- ) mice to produce compound Hpse-/- ;Ext1f/f ;Agr-CreER mice. Tamoxifen injection of standard juvenile Ext1f/f ;Agr-CreER mice elicited stochastic Ext1 ablation in growth plate and perichondrium, followed by osteochondroma formation, as revealed by microcomputed tomography and histochemistry. When we examined companion conditional Ext1-deficient mice lacking Hpse also, we detected no major decreases in osteochondroma number, skeletal distribution, and overall structure by the analytical criteria above. The Ext1 mutants used here closely mimic human HME pathogenesis, but have not been previously tested for responsiveness to treatments. To exclude some innate therapeutic resistance in this stochastic model, tamoxifen-injected Ext1f/f ;Agr-CreER mice were administered daily doses of the retinoid Palovarotene, previously shown to prevent ectopic cartilage and bone formation in other mouse disease models. This treatment did inhibit osteochondroma formation compared with vehicle-treated mice. Our data indicate that heparanase is not a major factor in osteochondroma initiation and accumulation in mice. Possible roles of heparanase upregulation in disease severity in patients are discussed.

Role of Heparanase and Syndecan-1 in HSV-1 Release from Infected Cells

Herpes Simplex Virus 1 (HSV-1) is a neurotropic human virus that belongs to the Alphaherpesvirinae subfamily of Herpesviridae. Establishment of its productive infection and progression of disease pathologies depend largely on successful release of virions from the virus-producing cells. HSV-1 is known to exploit many host factors for its release. Recent studies have shown that heparanase (HPSE) is one such host enzyme that is recruited for this purpose. It is an endoglycosidase that cleaves heparan sulfate (HS) from the surface of infected cells. HS is a virus attachment coreceptor that is commonly found on cell surfaces as HS proteoglycans e.g., syndecan-1 (SDC-1). The current model suggests that HSV-1 during the late stage of infection upregulates HPSE, which in turn enhances viral release by removing the virus-trapping HS moieties. In addition to its role in directly enabling viral release, HPSE accelerates the shedding of HS-containing ectodomains of SDC-1, which enhances HSV-1 release via a similar mechanism by upregulating CREB3 and COPII proteins. This review outlines the role of HPSE and SDC-1 as newly assigned host factors that facilitate HSV-1 release during a lytic infection cycle.

Mechanism-based heparanase inhibitors reduce cancer metastasis in vivo

Cancer growth is accompanied by changes to the extracellular environment of tumors, which aids the proliferation and spread of cancer cells. Cancer-associated extracellular matrix changes include excessive degradation of heparan sulfate carbohydrates, promoting metastatic spread by multiple mechanisms. Heparanase is the main human enzyme responsible for extracellular heparan sulfate breakdown and strongly drives metastasis when overexpressed. Few effective heparanase inhibitors are known, and the most effective molecules to date possess nondrug-like structures with multiple off-target effects. We have carried out structure-guided development of heparanase inhibitors, which covalently bind to the enzyme active site to cause irreversible inhibition. These inhibitors are heparanase specific and reduce metastasis in animal models with comparable efficacy to current “best-in-class” compounds.

Heparan sulfate proteoglycans (HSPGs) mediate essential interactions throughout the extracellular matrix (ECM), providing signals that regulate cellular growth and development. Altered HSPG composition during tumorigenesis strongly aids cancer progression. Heparanase (HPSE) is the principal enzyme responsible for extracellular heparan sulfate catabolism and is markedly up-regulated in aggressive cancers. HPSE overactivity degrades HSPGs within the ECM, facilitating metastatic dissemination and releasing mitogens that drive cellular proliferation. Reducing extracellular HPSE activity reduces cancer growth, but few effective inhibitors are known, and none are clinically approved. Inspired by the natural glycosidase inhibitor cyclophellitol, we developed nanomolar mechanism-based, irreversible HPSE inhibitors that are effective within physiological environments. Application of cyclophellitol-derived HPSE inhibitors reduces cancer aggression in cellulo and significantly ameliorates murine metastasis. Mechanism-based irreversible HPSE inhibition is an unexplored anticancer strategy. We demonstrate the feasibility of such compounds to control pathological HPSE-driven malignancies.

Vascular Endothelial Glycocalyx Damage and Potential Targeted Therapy in COVID-19

COVID-19 is a highly infectious respiratory disease caused by a new coronavirus known as SARS-CoV-2. COVID-19 is characterized by progressive respiratory failure resulting from diffuse alveolar damage, inflammatory infiltrates, endotheliitis, and pulmonary and systemic coagulopathy forming obstructive microthrombi with multi-organ dysfunction, indicating that endothelial cells (ECs) play a central role in the pathogenesis of COVID-19. The glycocalyx is defined as a complex gel-like layer of glycosylated lipid–protein mixtures, which surrounds all living cells and acts as a buffer between the cell and the extracellular matrix. The endothelial glycocalyx layer (EGL) plays an important role in vascular homeostasis via regulating vascular permeability, cell adhesion, mechanosensing for hemodynamic shear stresses, and antithrombotic and anti-inflammatory functions. Here, we review the new findings that described EGL damage in ARDS, coagulopathy, and the multisystem inflammatory disease associated with COVID-19. Mechanistically, the inflammatory mediators, reactive oxygen species (ROS), matrix metalloproteases (MMPs), the glycocalyx fragments, and the viral proteins may contribute to endothelial glycocalyx damage in COVID-19. In addition, the potential therapeutic strategies targeting the EGL for the treatment of severe COVID-19 are summarized and discussed.

CREB3 Plays an Important Role in HPSE-Facilitated HSV-1 Release in Human Corneal Epithelial Cells

Herpes simplex virus type-1 (HSV-1) exploits several host factors to enhance its replication and release from infected cells. It induces the production of host enzyme heparanase (HPSE) to aid in egress. While the mechanism by which HPSE assists in viral release is well-characterized, other host factors that are recruited along with HPSE for viral release are less well understood. In this study, we identify cyclic-AMP-responsive element-binding protein3 (CREB3) as a key player in HPSE-facilitated HSV-1 egress. When CREB3 is transiently upregulated in human corneal epithelial cells, HSV-1 release from the infected cells is correspondingly enhanced. This activity is linked to HPSE expression such that HPSE-transfected corneal epithelial (HCE) cells more highly express CREB3 than wild-type cells while the cells knocked out for HPSE show very little CREB3 expression. CREB3-transfected HCE cells showed significantly higher export of HPSE upon infection than wild-type cells. Our data suggests that coat protein complex II (COPII), which mediates HPSE trafficking, is also upregulated via a CREB3-dependent pathway during HSV-1 infection. Finally, the co-transfection of CREB3 and HPSE in HCE cells shows the highest viral release compared to either treatment alone, establishing CREB3 as a key player in HPSE-facilitated HSV-1 egress.

Resveratrol Decreases the Invasion Potential of Gastric Cancer Cells

The cancer-preventive agent Resveratrol (RSV) [3,5,4′-trihydroxytrans-stilbene] is a widely recognized antioxidant molecule with antitumoral potential against several types of cancers, including prostate, hepatic, breast, skin, colorectal, and pancreatic. Herein, we studied the effect of RSV on the cell viability and invasion potential of gastric cancer cells. AGS and MKN45 cells were treated with different doses of RSV (0–200 μM) for 24 h. Cell viability was determined using the Sulphorhodamine B dye (SRB) assay. For invasion assays, gastric cells were pre-treated with RSV (5–25 μM) for 24 h and then seeded in a Transwell chamber with coating Matrigel. The results obtained showed that RSV inhibited invasion potential in both cell lines. Moreover, to elucidate the mechanism implicated in this process, we analyzed the effects of RSV on SOD, heparanase, and NF-κB transcriptional activity. The results indicated that RSV increased SOD activity in a dose-dependent manner. Conversely, RSV significantly reduced the DNA-binding activity of NF-κB and the enzymatic activity of heparanase in similar conditions, which was determined using ELISA-like assays. In summary, these results show that RSV increases SOD activity but decreases NF-kB transcriptional activity and heparanase enzymatic activity, which correlates with the attenuation of invasion potential in gastric cancer cells. To our knowledge, no previous study has described the effect of RSV on heparanase activity. This article proposes that heparanase could be a key effector in the invasive events occurring during gastric cancer metastasis.

Sulfated Hyaluronan Binds to Heparanase and Blocks Its Enzymatic and Cellular Actions in Carcinoma Cells

We examined whether sulfated hyaluronan exerts inhibitory effects on enzymatic and biological actions of heparanase, a sole endo-beta-glucuronidase implicated in cancer malignancy and inflammation. Degradation of heparan sulfate by human and mouse heparanase was inhibited by sulfated hyaluronan. In particular, high-sulfated hyaluronan modified with approximately 2.5 sulfate groups per disaccharide unit effectively inhibited the enzymatic activity at a lower concentration than heparin. Human and mouse heparanase bound to immobilized sulfated hyaluronan. Invasion of heparanase-positive colon-26 cells and 4T1 cells under 3D culture conditions was significantly suppressed in the presence of high-sulfated hyaluronan. Heparanase-induced release of CCL2 from colon-26 cells was suppressed in the presence of sulfated hyaluronan via blocking of cell surface binding and subsequent intracellular NF-κB-dependent signaling. The inhibitory effect of sulfated hyaluronan is likely due to competitive binding to the heparanase molecule, which antagonizes the heparanase-substrate interaction. Fragment molecular orbital calculation revealed a strong binding of sulfated hyaluronan tetrasaccharide to the heparanase molecule based on electrostatic interactions, particularly characterized by interactions of (−1)- and (−2)-positioned sulfated sugar residues with basic amino acid residues composing the heparin-binding domain-1 of heparanase. These results propose a relevance for sulfated hyaluronan in the blocking of heparanase-mediated enzymatic and cellular actions.

Implications of Heparanase on Heparin Synthesis and Metabolism in Mast Cells

Heparin is a polysaccharide expressed in animal connective tissue-type mast cells. Owing to the special pentasaccharide sequence, heparin specifically binds to antithrombin (AT) and increases the inhibitory activity of AT towards coagulation enzymes. Heparin isolated from porcine intestinal mucosa has an average molecular weight of 15 kDa, while heparins recovered from rat skin and the peritoneal cavity were 60–100 kDa and can be fragmented by the endo-glucuronidase heparanase in vitro. In this study, we have examined heparin isolated from in vitro matured fetal skin mast cells (FSMC) and peritoneal cavity mast cells (PCMC) collected from wildtype (WT), heparanase knockout (Hpa-KO), and heparanase overexpressing (Hpa-tg) mice. The metabolically ³⁵S-labeled heparin products from the mast cells of WT, Hpa-KO, and Hpa-tg mice were compared and analyzed for molecular size and AT-binding activity. The results show that PCMC produced heparins with a size similar to heparin from porcine intestinal mast cells, whilst FSMC produced much longer chains. As expected, heparanase overexpression resulted in the generation of smaller fragments in both cell types, while heparins recovered from heparanase knockout cells were slightly longer than heparin from WT cells. Unexpectedly, we found that heparanase expression affected the production of total glycosaminoglycans (GAGs) and the proportion between heparin and other GAGs but essentially had no effect on heparin catabolism.

Heparanase Blockade as a Novel Dual-Targeting Therapy for COVID-19

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused over 5 million deaths worldwide. Pneumonia and systemic inflammation contribute to its high mortality. Many viruses use heparan sulfate proteoglycans as coreceptors for viral entry, and heparanase (HPSE) is a known regulator of both viral entry and inflammatory cytokines. We evaluated the heparanase inhibitor Roneparstat, a modified heparin with minimum anticoagulant activity, in pathophysiology and therapy for COVID-19. We found that Roneparstat significantly decreased the infectivity of SARS-CoV-2, SARS-CoV-1, and retroviruses (human T-lymphotropic virus 1 [HTLV-1] and HIV-1) in vitro. Single-cell RNA sequencing (scRNA-seq) analysis of cells from the bronchoalveolar lavage fluid of COVID-19 patients revealed a marked increase in HPSE gene expression in CD68⁺ macrophages compared to healthy controls. Elevated levels of HPSE expression in macrophages correlated with the severity of COVID-19 and the expression of inflammatory cytokine genes, including IL6, TNF, IL1B, and CCL2. In line with this finding, we found a marked induction of HPSE and numerous inflammatory cytokines in human macrophages challenged with SARS-CoV-2 S1 protein. Treatment with Roneparstat significantly attenuated SARS-CoV-2 S1 protein-mediated inflammatory cytokine release from human macrophages, through disruption of NF-κB signaling. HPSE knockdown in a macrophage cell line also showed diminished inflammatory cytokine production during S1 protein challenge. Taken together, this study provides a proof of concept that heparanase is a target for SARS-CoV-2-mediated pathogenesis and that Roneparstat may serve as a dual-targeted therapy to reduce viral infection and inflammation in COVID-19.

IMPORTANCE The complex pathogenesis of COVID-19 consists of two major pathological phases: an initial infection phase elicited by SARS-CoV-2 entry and replication and an inflammation phase that could lead to tissue damage, which can evolve into acute respiratory failure or even death. While the development and deployment of vaccines are ongoing, effective therapy for COVID-19 is still urgently needed. In this study, we explored HPSE blockade with Roneparstat, a phase I clinically tested HPSE inhibitor, in the context of COVID-19 pathogenesis. Treatment with Roneparstat showed wide-spectrum anti-infection activities against SARS-CoV-2, HTLV-1, and HIV-1 in vitro. In addition, HPSE blockade with Roneparstat significantly attenuated SARS-CoV-2 S1 protein-induced inflammatory cytokine release from human macrophages through disruption of NF-κB signaling. Together, this study provides a proof of principle for the use of Roneparstat as a dual-targeting therapy for COVID-19 to decrease viral infection and dampen the proinflammatory immune response mediated by macrophages.

Heparanase Inhibition Prevents Liver Steatosis in E0 Mice

Background: Non-alcoholic fatty liver disease affects up to 30% of adults in the USA, and is associated with a higher incidence of chronic liver morbidity and mortality. Several molecular pathways are involved in the pathology of liver steatosis, including lipid uptake, lipogenesis, lipolysis, and beta-oxidation. The enzyme heparanase has been implicated in liver steatosis. Herein, we investigated the effect of heparanase inhibition on liver steatosis in E₀ mice. Methods: In vivo experiments: Male wild-type mice fed with either chow diet (n = 4) or high-fat diet (n = 6), and male E₀ mice fed with chow diet (n = 8) or high-fat diet (n = 33) were included. Mice on a high-fat diet were treated for 12 weeks with PG545 at low dose (6.4 mg/kg/week, ip, n = 6) or high dose (13.3 mg/kg/week, ip, n = 7), SST0001 (1.2 mg/mouse/day, ip, n = 6), or normal saline (control, n = 14). Animals were sacrificed two days after inducing peritonitis. Serum was analyzed for biochemical parameters. Mouse peritoneal macrophages (MPMs) were harvested and analyzed for lipid content. Livers were harvested for histopathological analysis of steatosis, lipid content, and the expression of steatosis-related factors at the mRNA level. In vitro experiments: MPMs were isolated from untreated E₀ mice aged 8–10 weeks and were cultured and treated with either PG545 or SST0001, both at 50 µg/mL for 24 h, followed by assessment of mRNA expression of steatosis related factors. Results: Heparanase inhibition significantly attenuated the development of liver steatosis, as was evident by liver histology and lipid content. Serum analysis indicated lowering of cholesterol and triglycerides levels in mice treated with heparanase inhibitors. In liver tissue, assessment of mRNA expression of key factors in lipid uptake, lipolysis, lipogenesis, and beta-oxidation exhibited significant downregulation following PG545 treatment and to a lesser extent when SST0001 was applied. However, in vitro treatment of MPMs with PG545, but not SST0001, resulted in increased lipid content in these cells, which is opposed to their effect on MPMs of treated mice. This may indicate distinct regulatory pathways in the system or isolated macrophages following heparanase inhibition. Conclusion: Heparanase inhibition significantly attenuates the development of liver steatosis by decreasing tissue lipid content and by affecting the mRNA expression of key lipid metabolism regulators.

Increased Heparanase Levels in Urine during Acute Puumala Orthohantavirus Infection Are Associated with Disease Severity

Old–world orthohantaviruses cause hemorrhagic fever with renal syndrome (HFRS), characterized by acute kidney injury (AKI) with transient proteinuria. It seems plausible that proteinuria during acute HFRS is mediated by the disruption of the glomerular filtration barrier (GFB) due to vascular leakage, a hallmark of orthohantavirus–caused diseases. However, direct infection of endothelial cells by orthohantaviruses does not result in increased endothelial permeability, and alternative explanations for vascular leakage and diminished GFB function are necessary. Vascular integrity is partly dependent on an intact endothelial glycocalyx, which is susceptible to cleavage by heparanase (HPSE). To understand the role of glycocalyx degradation in HFRS–associated proteinuria, we investigated the levels of HPSE in urine and plasma during acute, convalescent and recovery stages of HFRS caused by Puumala orthohantavirus. HPSE levels in urine during acute HFRS were significantly increased and strongly associated with the severity of AKI and other markers of disease severity. Furthermore, increased expression of HPSE was detected in vitro in orthohantavirus–infected podocytes, which line the outer surfaces of glomerular capillaries. Taken together, these findings suggest the local activation of HPSE in the kidneys of orthohantavirus–infected patients with the potential to disrupt the endothelial glycocalyx, leading to increased protein leakage through the GFB, resulting in high amounts of proteinuria.

Structural Insights into Pixatimod (PG545) Inhibition of Heparanase, a Key Enzyme in Cancer and Viral Infections

Pixatimod (PG545), a heparan sulfate (HS) mimetic and anticancer agent currently in clinical trials, is a potent inhibitor of heparanase. Heparanase is an endo‐β‐glucuronidase that degrades HS in the extracellular matrix and basement membranes and is implicated in numerous pathological processes such as cancer and viral infections, including SARS−CoV‐2. To understand how PG545 interacts with heparanase, we firstly carried out a conformational analysis through a combination of NMR experiments and molecular modelling which showed that the reducing end β‐D‐glucose residue of PG545 adopts a distorted conformation. This was followed by docking and molecular dynamics simulations to study the interactions of PG545 with heparanase, revealing that PG545 is able to block the active site by binding in different conformations, with the cholestanol side‐chain making important hydrophobic interactions. While PG545 blocks its natural substrate HS from binding to the active site, small synthetic heparanase substrates are only partially excluded, and thus pentasaccharide or larger substrates are preferred for assaying this class of inhibitor. This study provides new insights for the design of next‐generation heparanase inhibitors and substrates.

Novel Therapeutic Targets and Immune Dysfunction in Malignant Pleural Mesothelioma

Advances in the treatment of malignant pleural mesothelioma (MPM) have been disappointing, despite the apparent need for new therapeutic options for this rare and devastating cancer. Drug resistance is common and surgical intervention has brought benefits only to a subset of patients. MPM is a heterogenous disease with a surprisingly low mutation rate and recent sequencing efforts have confirmed alterations in a limited number of tumor suppressors that do not provide apparent insights into the molecular mechanisms that drive this malignancy. There is increasing evidence that epigenetic regulation leads to immune evasion and transformation in MPM. Further, the low efficacy of immune checkpoint inhibitors is consistent with a suppression of genes involved in the anti-tumor immune response. We review three promising emerging therapeutic targets (STAT3, KDM4A, heparanase) and highlight their potential effects on the immune response.

Endothelial Dysfunction in Fabry Disease Is Related to Glycocalyx Degradation

Fabry disease (FD) is an X-linked multisystemic lysosomal storage disease due to a deficiency of α-galactosidase A (GLA/AGAL). Progressive cellular accumulation of the AGAL substrate globotriaosylceramide (Gb₃) leads to endothelial dysfunction. Here, we analyzed endothelial function in vivo and in vitro in an AGAL-deficient genetic background to identify the processes underlying this small vessel disease. Arterial stiffness and endothelial function was prospectively measured in five males carrying GLA variants (control) and 22 FD patients under therapy. AGAL-deficient endothelial cells (EA.hy926) and monocytes (THP1) were used to analyze endothelial glycocalyx structure, function, and underlying inflammatory signals. Glycocalyx thickness and small vessel function improved significantly over time (p<0.05) in patients treated with enzyme replacement therapy (ERT, n=16) and chaperones (n=6). AGAL-deficient endothelial cells showed reduced glycocalyx and increased monocyte adhesion (p<0.05). In addition, increased expression of angiopoietin-2, heparanase and NF-κB was detected (all p<0.05). Incubation of wild-type endothelial cells with pathological globotriaosylsphingosine concentrations resulted in comparable findings. Treatment of AGAL-deficient cells with recombinant AGAL (p<0.01), heparin (p<0.01), anti-inflammatory (p<0.001) and antioxidant drugs (p<0.05), and a specific inhibitor (razuprotafib) of angiopoietin-1 receptor (Tie2) (p<0.05) improved glycocalyx structure and endothelial function in vitro. We conclude that chronic inflammation, including the release of heparanases, appears to be responsible for the degradation of the endothelial glycocalyx and may explain the endothelial dysfunction in FD. This process is partially reversible by FD-specific and anti-inflammatory treatment, such as targeted protective Tie2 treatment.

Release of HSV-1 Cell-Free Virions: Mechanisms, Regulation, and Likely Role in Human-Human Transmission

Herpes simplex virus type 1, or HSV-1, is a widespread human pathogen that replicates in epithelial cells of the body surface and then establishes latent infection in peripheral neurons. When HSV-1 replicates, viral progeny must be efficiently released to spread infection to new target cells. Viral spread occurs via two major routes. In cell-cell spread, progeny virions are delivered directly to cellular junctions, where they infect adjacent cells. In cell-free release, progeny virions are released into the extracellular milieu, potentially allowing the infection of distant cells. Cell-cell spread of HSV-1 has been well studied and is known to be important for in vivo infection and pathogenesis. In contrast, HSV-1 cell-free release has received less attention, and its significance to viral biology is unclear. Here, I review the mechanisms and regulation of HSV-1 cell-free virion release. Based on knowledge accrued in other herpesviral systems, I argue that HSV-1 cell-free release is likely to be tightly regulated in vivo. Specifically, I hypothesize that this process is generally suppressed as the virus replicates within the body, but activated to high levels at sites of viral reactivation, such as the oral mucosa and skin, in order to promote efficient transmission of HSV-1 to new human hosts.

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.

A Marine λ-Oligocarrageenan Inhibits Migratory and Invasive Ability of MDA-MB-231 Human Breast Cancer Cells through Actions on Heparanase Metabolism and MMP-14/MMP-2 Axis

Sugar-based molecules such as heparins or natural heparan sulfate polysaccharides have been developed and widely studied for controlling heparanase (HPSE) enzymatic activity, a key player in extracellular matrix remodelling during cancer pathogenesis. However, non-enzymatic functions of HPSE have also been described in tumour mechanisms. Given their versatile properties, we hypothesized that sugar-based inhibitors may interfere with enzymatic but also non-enzymatic HPSE activities. In this work, we assessed the effects of an original marine λ-carrageenan derived oligosaccharide (λ-CO) we previously described, along with those of its native counterpart and heparins, on cell viability, proliferation, migration, and invasion of MDA-MB-231 breast cancer cells but also of sh-MDA-MB-231 cells, in which the expression of HPSE was selectively downregulated. We observed no cytotoxic and no anti-proliferative effects of our compounds but surprisingly λ-CO was the most efficient to reduce cell migration and invasion compared with heparins, and in a HPSE-dependent manner. We provided evidence that λ-CO tightly controlled a HPSE/MMP-14/MMP-2 axis, leading to reduced MMP-2 activity. Altogether, this study highlights λ-CO as a potent HPSE “modulator” capable of reducing not only the enzymatic activity of HPSE but also the functions controlled by the HPSE levels.

Heparanase is a novel biomarker for immune infiltration and prognosis in breast cancer

Heparanase (HPSE), an endoglycosidase that cleaves heparan sulfate, regulates a variety of biological processes that promote tumor progression. In this study, we analyzed the correlation between HPSE expression and prognosis in cancer patients, using multiple databases (Oncomine, TIMER, PrognoScan, GEPIA, Kaplan-Meier plotter, miner v4.1, DAVID). HPSE expression was significantly increased in bladder, breast, lung, and stomach cancer compared to matched normal tissues. The increased HPSE expression correlated with poor prognosis and increased immune infiltration levels of B cells, CD8+ and CD4+ T cells, macrophages, neutrophils and dendritic cells in bladder and breast cancer. In breast cancer, the high HPSE expression was associated with basal-like subtypes, younger age (0-40), advanced Scarff-Bloom-Richardson grade, Nottingham Prognostic Index and p53 mutation status. In addition, using a mouse model of breast cancer, our data showed that HPSE upregulated IL-10 expression and promoted macrophage M2 polarization and T cell exhaustion. Together, our data provide a novel immunological perspective on the mechanisms underlying breast cancer progression, and indicate that HPSE may serve as a biomarker for immune infiltration and prognosis in breast cancer.

A porcine model of endothelial glycocalyx damage by enzymatic digestion: A pilot study

BACKGROUND

The endothelial glycocalyx (EG) plays a vital role in the physiology and pathophysiology of human microcirculation. Having relevant EG damage model would be important tool for testing new interventions aiming at EG protection and recovery. We describe the first in vivo EG damage model in pig.

OBJECTIVE

To investigate the course of animal EG damage induced by specific enzymes.

MATERIAL AND METHODS

Four anesthetized piglets received enzymes: 1g hyaluronidase and 25 IU heparanase I intravenously. Blood and urine samples were collected at baseline and 20/40/60/80/100/120 min for detecting markers of endothelial and EG function. Sublingual microcirculation and EG thickness were assessed by Side-stream Dark Field (SDF) imaging and Perfused Boundary Region (PBR) respectively. EG of the mesentery artery was visualized in fluorescent microscopy.

RESULTS

Biochemical marker of EG damage syndecan-1 showed temporary increase with return to baseline and was reflected by PBR values. Albumin levels suggested brief period of capillary leakage (decrease in the serum, increase in the urine) with a trend to normalization. Urine glycosaminoglycans peaked at 120 minutes. Microcirculatory perfusion parameter showed significant alteration. Diffusion parameters were altered with no statistical significance.

CONCLUSION

EG damage induced by specific enzymes was reflected by temporary changes of biochemical makers together with alteration of microcirculation and changes in fluorescent microscopy of EG layer. Our results support to further validate presented model of EG damage on a larger number of animals.

Heparanase confers temozolomide resistance by regulation of exosome secretion and circular RNA composition in glioma

Temozolomide (TMZ) resistance is the main challenge in the management of glioma patients. Heparanase can mediate the secretion and function of exosomes, which are considered to be a promising molecular delivery system for cancer therapy. Therefore, this study aimed to investigate whether heparanase‐mediated delivery of exosomes was related to TMZ resistance of glioma. Heparanase was upregulated in TMZ‐resistant glioma cells, and overexpression of heparanase led to increased resistance of U87 cells to TMZ. Knockdown of heparanase led to increased sensitivity of TMZ‐resistant U251 cells (U251R) cells to TMZ. Heparanase promoted the secretion of exosomes from glioma cells, and coculture with exosomes derived from heparanase knockdown U251R cells partly restored the sensitivity of U251 cells to TMZ compared with exosomes derived from si‐control transfected U251R cells. It was identified by circular RNA microarrays that hsa_circ_0042003 was upregulated in exosomes derived from U251R, which could be positively regulated by heparanase. U251R cell‐derived exosomal hsa_circ_0042003 conferred the resistance of U251 cells to TMZ. In vivo studies also showed that U251R cell‐derived exosomes induced resistance of U251 cells to TMZ, and the combination of tail‐injected exosomal si‐heparanase or exosomal si‐hsa_circ_0042003 and intraperitoneal TMZ applied to nude mice abolished TMZ resistance. Heparanase mediated the transfer of exosomal hsa_circ_0042003 from TMZ‐resistant glioma cells to drug‐sensitive cells, which contributed to the chemoresistance of glioma to TMZ.

From Cancer to COVID-19: A Perspective on Targeting Heparan Sulfate-Protein Interactions

Heparan sulfate (HS) is a complex, polyanionic polysaccharide ubiquitously expressed on cell surfaces and in the extracellular matrix. HS interacts with numerous proteins to mediate a vast array of biological and pathological processes. Inhibition of HS‐protein interactions is thus an attractive approach for new therapeutic development for cancer and infectious diseases, including COVID‐19; however, synthesis of well‐defined native HS oligosaccharides remains challenging. This has aroused significant interest in the development of HS mimetics which are more synthetically tractable and have fewer side effects, such as undesired anticoagulant activity. This account provides a perspective on the design and synthesis of different classes of HS mimetics with useful properties, and the development of various assays and molecular modelling tools to progress our understanding of their interactions with HS‐binding proteins.

pylori Colonization and Gastritis

Chronic gastritis caused by Helicobacter pylori (H. pylori) infection has been widely recognized as the most important risk factor for gastric cancer. Analysis of the interaction between the key participants in gastric mucosal immunity and H. pylori infection is expected to provide important insights for the treatment of chronic gastritis and the prevention of gastric cancer. Heparanase is an endoglycosidase that degrades heparan sulfate, resulting in remodeling of the extracellular matrix thereby facilitating the extravasation and migration of immune cells towards sites of inflammation. Heparanase also releases heparan sulfate-bound cytokines and chemokines that further promote directed motility and recruitment of immune cells. Heparanase is highly expressed in a variety of inflammatory conditions and diseases, but its role in chronic gastritis has not been sufficiently explored. In this study, we report that H. pylori infection promotes up-regulation of heparanase in gastritis, which in turn facilitates the colonization of H. pylori in the gastric mucosa, thereby aggravating gastritis. By sustaining continuous activation, polarization and recruitment of macrophages that supply pro-inflammatory and pro-tumorigenic cytokines (i.e., IL-1, IL-6, IL-1β, TNF-α, MIP-2, iNOS), heparanase participates in the generation of a vicious circle, driven by enhanced NFκB and p38-MAPK signaling, that supports the development and progression of gastric cancer. These results suggest that inhibition of heparanase may block this self-sustaining cycle, and thereby reduce the risk of gastritis and gastric cancer.

Progestin type affects the increase of heparanase level and procoagulant activity mediated by the estrogen receptor

STUDY QUESTION

Does progestin have an effect on heparanase level and procoagulant activity?

SUMMARY ANSWER

Progestin increases the heparanase level and procoagulant activity via the estrogen receptor and the magnitude of the effect depends on the progestin type.

WHAT IS KNOWN ALREADY

Users of combined oral contraceptives (COCs) containing third- and fourth-generation progestins have a higher risk of venous thrombosis compared to those employing second-generation progestins. Heparanase protein is capable of degrading heparan sulfate (HS) chains and enhancing activation of the coagulation system. We have previously demonstrated that estrogen enhances the expression and procoagulant activity of heparanase.

STUDY DESIGN, SIZE, DURATION

Estrogen and progestin receptor positive breast carcinoma cell lines: EMT6, T47D and MCF-7 were compared to the MDA-231 breast carcinoma cell line devoid of these receptors. This observational study incorporated 45 users of third-generation COCs progestins, 21 users of fourth-generation COCs progestins and 28 individuals not using hormonal therapy and not pregnant per history.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Second-generation progestin-levonorgestrel, third-generation progestin-desogastrel (DSG), an estrogen receptor antagonist-ICI 182.780 and a progestin receptor antagonist-mifepristone, were added to cell lines. Heparanase level and procoagulant activity, HS levels, tissue factor (TF) activity and factor Xa levels were evaluated in the plasma of the study group.

MAIN RESULTS AND THE ROLE OF CHANCE

Levonorgestrel and DSG increased heparanase levels in the cells and medium. The effect of DSG was more prominent and additive to that of estrogen. The effect was inhibited by ICI 182.780. In the plasma of COC users, heparanase procoagulant activity, HS levels, TF activity and factor Xa levels were significantly higher compared to controls. In COC pills containing the same dose of estrogen, the procoagulant effect of drospirenone was significantly stronger than that of DSG and gestodene.

LIMITATIONS, REASONS FOR CAUTION

The limitations of the study include a small number of participants in each study group, although the results are statistically significant and evaluated by several different coagulation parameters.

WIDER IMPLICATIONS OF THE FINDINGS

The study demonstrates a new mechanism through which progestin affects coagulation system activation and shows that this effect is progestin type-dependent. Development of a progestin derivative with an attenuated effect on heparanase procoagulant activity may reduce thrombotic risk.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was sought for this study. Y.N. is named in a European patent application No. IL201200027 filed on 18 January 2012. Other authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Impact of Adjuvant Treatment on Heparanase Concentration in Invasive, Unilateral Breast Cancer Patients: Results of a Prospective Single-Centre Cohort Study

Background: In recent years, great progress has been made in the treatment of breast cancer, but it is still one of the ten leading causes of death in women. The aim of the study was to evaluate the heparanase concentration of invasive breast cancer (IBrC) patients, before and after cancer adjuvant treatment. Methods: Eighty patients with stage IA to IIB IBrC receiving adjuvant treatment were included prospectively in this study. The heparanase concentrations were determined by an enzyme-linked immunosorbent assay. A univariate analysis was used to estimate the factors influencing the low or high pre-treatment concentration of heparanase and the low or high numerical decrease in heparanase concentration after completion of adjuvant treatment. Results: Treatment reduced the concentration of heparanase by almost four times in the general IBrC cohort. Higher levels of pre- and post-treatment heparanase were noted in oestrogen receptor-negative cancers than in positive ones. A higher post-treatment concentration of heparanase was found in patients with a triple-negative tumour compared to patients with a luminal B HER2 negative type of IBrC. Overweight IBrC subjects and those with a tumour diameter of ≥2 cm demonstrated a lower chance of a lower pre-treatment heparanase concentration. Interestingly, a pre-treatment heparanase concentration is the main predictor of the changes in heparanase concentration after adjuvant treatment. Follow-up revealed significantly lower progression-free survival (PFS) rates in IBrC patients with a pre-treatment concentration of heparanase higher than 181.46 pg/mL (PFS = 80%). Conclusions: Our findings provide supporting evidence that IBrC therapy reduced the heparanase levels, regardless of treatment patterns and a pre-treatment concentration of heparanase may serve as a prognostic indicator for future outcomes.

Synthesis, Cytotoxic and Heparanase Inhibition Studies of 5-oxo-1-arylpyrrolidine-3- carboxamides of Hydrazides and 4-amino-5-aryl-4H-1,2,4-triazole-3-thiol

Design of chemically novel, biologically potent small heterocyclic molecules with anticancer activities, which targets the enzyme heparanase has gained prominent clinical interest. We have synthesized a novel class of carboxamide derivatives by coupling various substituted aromatic acid hydrazides and triazoleamine with pyrrolidine carboxylic acid by using coupling agents. The synthesized compounds are characterized by spectroscopic techniques such as FT-IR, HRMS and NMR. These compounds are investigated for cytotoxicity on different cancer cell lines and heparanase inhibitory activity. Most of them showed moderate heparanase inhibitory activity and good cytotoxicity.

Heparanase expression and activity are increased in platelets during clinical sepsis

BACKGROUND

Heparanase (HPSE) is the only known mammalian enzyme that can degrade heparan sulfate. Heparan sulfate proteoglycans are essential components of the glycocalyx, and maintain physiological barriers between the blood and endothelial cells. HPSE increases during sepsis, which contributes to injurious glyocalyx degradation, loss of endothelial barrier function, and mortality.

OBJECTIVES

As platelets are one of the most abundant cellular sources of HPSE, we sought to determine whether HPSE expression and activity increases in human platelets during clinical sepsis. We also examined associations between platelet HPSE expression and clinical outcomes.

PATIENTS/METHODS

Expression and activity of HPSE was determined in platelets isolated from septic patients (n = 59) and, for comparison, sex-matched healthy donors (n = 46) using complementary transcriptomic, proteomic, and functional enzymatic assays. Septic patients were followed for the primary outcome of mortality, and clinical data were captured prospectively for septic patients.

RESULTS

The mRNA expression of HPSE was significantly increased in platelets isolated from septic patients. Ribosomal footprint profiling, followed by [S35] methionine labeling assays, demonstrated that HPSE mRNA translation and HPSE protein synthesis were significantly upregulated in platelets during sepsis. While both the pro- and active forms of HPSE protein increased in platelets during sepsis, only the active form of HPSE protein significantly correlated with sepsis-associated mortality. Consistent with transcriptomic and proteomic upregulation, HPSE enzymatic activity was also increased in platelets during sepsis.

CONCLUSIONS

During clinical sepsis HPSE, translation, and enzymatic activity are increased in platelets. Increased expression of the active form of HPSE protein is associated with sepsis-associated mortality.

MicroRNA-219a-2-3p modulates the proliferation of thyroid cancer cells via the HPSE/cyclin D1 pathway

Heparanase (HPSE) is an endo-β-D-glucuronidase overexpressed in different types of human cancer, and a predicted target of microRNA (miRNA/miR)-219a-2-3p in thyroid cancer. The present study aimed to investigate the potential role of HPSE and miR-219a-2-3p in thyroid cancer, and the molecular mechanism of miR-219a-2-3p regulating the proliferation of thyroid cancer cells via HPSE was confirmed. Immunohistochemistry analysis was performed to detect HPSE expression in thyroid cancer sections. In addition, reverse transcription-quantitative PCR analysis was performed to detect mRNA and miR-219a-2-3p expression levels in thyroid cancer samples and cell lines. miR-219-2-3p mimic or HPSE plasmid were transfected into B-CPAP and TPC-1 thyroid cancer cells. Furthermore, western blot analysis was performed to detect the protein expression levels of HPSE and cyclin D1. Cell cycle analysis was performed using propidium iodide staining and flow cytometry, and EdU incorporation was performed to detect cell proliferation. The results demonstrated that high HPSE expression was significantly associated with tumor size, extracapsular invasion and lymph node metastasis. Notably, a statistically negative correlation was observed between HPSE mRNA expression and miR-219a-2-3p expression in thyroid cancer tumors, as well as in thyroid cancer cell lines. When exogenously expressed in B-CPAP and TPC-1 cells, miR-219a-2-3p induced cell cycle arrest at the G⁰/G¹ phase and decreased the percentage of proliferating cells. Furthermore, HPSE and cyclin D1 protein expression decreased following transfection with miR-219a-2-3p. Notably, when HPSE was ectopically expressed in miR-219a-2-3p transfected cells, cyclin D1 expression and the number of proliferative cells increased. Taken together, these results suggest that HPSE contributes to the proliferation of thyroid cancer cells. In addition, miR-219a-2-3p was confirmed to target HPSE and inhibit cell proliferation, which was associated with cyclin D1 suppression-mediated cell cycle arrest.

Key Matrix Remodeling Enzymes: Functions and Targeting in Cancer

Tissue functionality and integrity demand continuous changes in distribution of major components in the extracellular matrices (ECMs) under normal conditions aiming tissue homeostasis. Major matrix degrading proteolytic enzymes are matrix metalloproteinases (MMPs), plasminogen activators, atypical proteases such as intracellular cathepsins and glycolytic enzymes including heparanase and hyaluronidases. Matrix proteases evoke epithelial-to-mesenchymal transition (EMT) and regulate ECM turnover under normal procedures as well as cancer cell phenotype, motility, invasion, autophagy, angiogenesis and exosome formation through vital signaling cascades. ECM remodeling is also achieved by glycolytic enzymes that are essential for cancer cell survival, proliferation and tumor progression. In this article, the types of major matrix remodeling enzymes, their effects in cancer initiation, propagation and progression as well as their pharmacological targeting and ongoing clinical trials are presented and critically discussed.

Structural Characterization and Heparanase Inhibitory Activity of Fucosylated Glycosaminoglycan from Holothuria floridana

Unique fucosylated glycosaminoglycans (FG) have attracted increasing attention for various bioactivities. However, the precise structures of FGs usually vary in a species-specific manner. In this study, HfFG was isolated from Holothuria floridana and purified by anion exchange chromatography with the yield of ~0.9%. HfFG was composed of GlcA, GalNAc and Fuc, its molecular weight was 47.3 kDa, and the -OSO3-/-COO- molar ratio was 3.756. HfFG was depolymerized by a partial deacetylation-deaminative cleavage method to obtain the low-molecular-weight HfFG (dHfFG). Three oligosaccharide fragments (Fr-1, Fr-2, Fr-3) with different molecular weights were isolated from the dHfFG, and their structures were revealed by 1D and 2D NMR spectroscopy. HfFG should be composed of repeating trisaccharide units -{(L-FucS-α1,3-)d-GlcA-β1,3-d-GalNAc4S6S-β1,4-}-, in which sulfated fucose (FucS) includes Fuc2S4S, Fuc3S4S and Fuc4S residues linked to O-3 of GlcA in a ratio of 45:35:20. Furthermore, the heparanase inhibitory activities of native HfFG and oligosaccharide fragments (Fr-1, Fr-2, Fr-3) were evaluated. The native HfFG and its oligosaccharides exhibited heparanase inhibitory activities, and the activities increased with the increase of molecular weight. Additionally, structural characteristics such as sulfation patterns, the terminal structure of oligosaccharides and the presence of fucosyl branches may be important factors affecting heparanase inhibiting activity.

A guide to the composition and functions of the extracellular matrix

Extracellular matrix (ECM) is a dynamic 3-dimensional network of macromolecules that provides structural support for the cells and tissues. Accumulated knowledge clearly demonstrated over the last decade that ECM plays key regulatory roles since it orchestrates cell signaling, functions, properties and morphology. Extracellularly secreted as well as cell-bound factors are among the major members of the ECM family. Proteins/glycoproteins, such as collagens, elastin, laminins and tenascins, proteoglycans and glycosaminoglycans, hyaluronan, and their cell receptors such as CD44 and integrins, responsible for cell adhesion, comprise a well-organized functional network with significant roles in health and disease. On the other hand, enzymes such as matrix metalloproteinases and specific glycosidases including heparanase and hyaluronidases contribute to matrix remodeling and affect human health. Several cell processes and functions, among them cell proliferation and survival, migration, differentiation, autophagy, angiogenesis, and immunity regulation are affected by certain matrix components. Structural alterations have been also well associated with disease progression. This guide on the composition and functions of the ECM gives a broad overview of the matrisome, the major ECM macromolecules, and their interaction networks within the ECM and with the cell surface, summarizes their main structural features and their roles in tissue organization and cell functions, and emphasizes the importance of specific ECM constituents in disease development and progression as well as the advances in molecular targeting of ECM to design new therapeutic strategies.

Inhibition of Tumor-Host Cell Interactions Using Synthetic Heparin Mimetics

Low-molecular-weight heparin (LMWH) is the guideline-based drug for antithrombotic treatment of cancer patients, while its direct antitumor effects are a matter of ongoing debate. Although therapeutically established for decades, LMWH has several drawbacks mainly associated with its origin from animal sources. Aiming to overcome these limitations, a library of synthetic heparin mimetic polymers consisting of homo- and copolymers of sulfonated and carboxylated noncarbohydrate monomers has recently been synthesized via reversible addition-fragmentation chain transfer polymerization. These heparin mimetics were investigated for their capacities to interfere with simulated steps of tumor cell metastasis. Among them, homo- and copolymers from sodium 4-styrenesulfonate (poly(SSS)) with acrylic acid (poly(SSS-co-AA)) with an MW between 5 and 50 kDa efficiently attenuated cancer cell-induced coagulation and thus platelet activation and degranulation similar to or even better than LMWH. Furthermore, independent of anticoagulant activities, these polymers affected other metastasis-relevant targets with impressive affinities. Hence, they blocked heparanase enzymatic activity outmatching commercial heparins or a glycosidic drug candidate. Furthermore, these polymers bind P-selectin and the integrin VLA-4 similar to or even better than heparin, indicated by a biosensor approach and thus efficiently blocked melanoma cell binding to endothelium under blood flow conditions. This is the first report on the prospects of synthetic heparin mimetics as promising nontoxic compounds in oncology to potentially substitute heparin as an anticoagulant and to better understand its role as an antimetastatic drug.