Heparan Research Articles

Synthesis of S-Glycoside Building Blocks as Mimetics of the Repeating d-GlcN-α-1,4-d-GlcA Heparan Sulfate Disaccharide

Heparan sulfate (HS), a sulfated linear carbohydrate that decorates the cell surface and extracellular matrix, is a key regulator of biological processes. Owing to the inherent structural complexity of HS, structure-to-function studies with its ligands are required, and materials to improve the understanding of such interactions are therefore of high importance. Herein, the synthesis of novel S-linked GlcN-α(1→4)-GlcA disaccharide building blocks is detailed. Initial attempts at constructing the desired disaccharide using d-GlcN donors and d-Glc/GlcA acceptors via an S-glycosylation failed. Reversing the reactivity polarity of the monosaccharide building blocks enabled successful SN2 coupling using α-d-GlcN thiohemiacetals and d-galactosyl triflates. Subsequent C6-oxidation furnished the desired S-linked GlcN-α(1→4)-GlcA disaccharide building blocks on a gram scale. Such disaccharides offer potential for incorporation into wider synthetic HS sequences to provide glycomimetic tools.

An integral membrane constitutively active heparanase enhances the tumor infiltration capability of NK cells

ABSTRACT Eradication of cancer cells by the immune system requires extravasation, infiltration and progression of immune cells through the tumor extracellular matrix (ECM). These are also critical determinants for successful adoptive cell immunotherapy of solid tumors. Together with structural proteins, such as collagens and fibronectin, heparan sulfate (HS) proteoglycans are major components of the ECM. Heparanase 1 (HPSE) is the only enzyme known to have endoglycosidase activity that degrades HS. HPSE is expressed at high levels in almost all hematopoietic cells, which suggests that it plays a relevant role in immune cell migration through solid tissues. Besides, tumor cells express also HPSE as a way to facilitate tumor cell resettlement and metastasis. Therefore, an increase in HPSE in the tumor ECM would be detrimental. Here, we analyzed the effects of constitutive expression of an active, membrane-bound HPSE on the ability of human natural killer (NK) cells to infiltrate tumors and eliminate tumor cells. We demonstrate that NK cells expressing a chimeric active form of HPSE on the cell surface as an integral membrane protein, display significantly enhanced infiltration capability into spheroids of various cancer cell lines, as well as into xenograft tumors in immunodeficient mice. As a result, tumor growth was significantly suppressed without causing noticeable side effects. Altogether, our results suggest that a constitutively expressed active HSPE on the surface of immune effector cells enhances their capability to access and eliminate tumor cells. This strategy opens new possibilities for improving adoptive immune treatments using NK cells.

Heparin in sepsis: current clinical findings and possible mechanisms

Sepsis is a clinical syndrome resulting from the interaction between coagulation, inflammation, immunity and other systems. Coagulation activation is an initial factor for sepsis to develop into multiple organ dysfunction. Therefore, anticoagulant therapy may be beneficial for sepsis patients. Heparin possesses a variety of biological activities, so it has a broad prospect in sepsis. Previous studies suggested that patients with sepsis-induced disseminated intravascular coagulation and high disease severity might be suitable for anticoagulant therapy. With the development of artificial intelligence (AI), recent studies have shown that patients with severe coagulation activation represent the targeted patients for anticoagulant therapy in sepsis. However, it remains necessary to accurately define the relevant biomarkers indicative of this phenotype and validate their clinical utility by large randomized controlled trials (RCTs). Analyses of data from early small RCTs, subgroup analyses of large RCTs and meta-analyses have collectively suggested that anticoagulant therapy, particularly the use of heparin, may be an effective approach for managing sepsis patients. Concurrently, debate persists regarding the optimal selection of anticoagulants, proper timing, usage and dosage of administration that should be employed to assess treatment efficacy. The primary mechanisms of heparin are acting on heparan sulfate, histones, high mobility group box 1 and heparin-binding protein, which interfere with the regulation of inflammation, vascular permeability, coagulation, endothelial function and other biological activities. However, the underlying pathophysiological processes mediating the potential therapeutic effects of heparin in the context of sepsis remain incompletely understood and warrant additional rigorous investigation to establish the mechanism more conclusively.

Pulp regeneration using a peptide nanofiber artificial scaffold on animal models: A preliminary study.

In regenerative endodontic procedures (REPs), it is crucial to find effective materials. This study introduces glycosaminoglycan (GAG) mimetic peptide amphiphile (PA, GAG-PA) and K-PA nanofibers, synthesized to emulate sulfated GAGs, aiming to enhance tissue repair within damaged pulp - an area where standardized protocols are currently lacking. The objective of this study was to investigate the regenerative potential of GAG-PA nanofibers in REP. Heparan sulfate mimicking PAs was designed to develop a bioactive nanofibrous supramolecular system. The cavities on the mesial surfaces of the first upper molars of 8 rats (4 rats in the study group and 4 in the control group) were prepared, and the pulps were perforated. Then, the material was applied onto the dental pulp, and the cavities were closed with a self-curing glass ionomer cement filling material. Physiological saline was used in the control group. Thirty days after application, the teeth were extracted, and the formation of regenerative tissue sections in the pulp was evaluated using hematoxylin and eosin (H&E) staining and Masson's trichrome staining. After 30 days, H&E staining demonstrated robust tissue regeneration in the implanted region, with minimal neutrophil infiltration. Masson's trichrome staining confirmed reparative dentin formation. Quantitative analysis revealed a regeneration percentage of 85% in the study group, compared to 80% in the control group. Statistical analysis showed no significant difference in regeneration between the groups (p > 0.05). Our comprehensive study, utilizing GAG-PA and K-PA nanofibers, demonstrated successful synthesis, characterization and formation of nanofiber networks. The in vivo experiment with rats exhibited substantial tissue regeneration with quantifiable results supporting the efficacy of the nanofiber approach. Statistical analysis confirmed the consistency between the study and control groups, emphasizing the potential of these nanofibers in endodontic tissue regeneration applications.

Dissecting metabolic landscape of alveolar macrophage

The highly plastic nature of Alveolar Macrophage (AM) plays a crucial role in the defense against inhaled particulates and pathogens in the lungs. Depending on the signal, AM acquires either the classically activated M1 phenotype or the alternatively activated M2 phenotype. In this study, we investigate the metabolic shift in the activated phases of AM (M1 and M2 phases) by reconstructing context specific Genome-Scale Metabolic (GSM) models. Metabolic pathways such as pyruvate metabolism, arachidonic acid metabolism, chondroitin/heparan sulfate biosynthesis, and heparan sulfate degradation are found to be important driving forces in the development of the M1/M2 phenotypes. Additionally, we formulated a bilevel optimization framework named MetaShiftOptimizer to identify minimal modifications that shift one activated state (M1/M2) to the other. The identified reactions involve metabolites such as glycogenin, L-carnitine, 5-hydroperoxy eicosatetraenoic acid, and leukotriene B4, which show potential to be further investigated as significant factors for developing efficient therapy targets for severe respiratory disorders in the future. Overall, our study contributes to the understanding of the metabolic capabilities of the M1 and M2 phenotype of AM and identifies pathways and reactions that can be potential targets for polarization shift and also be used as therapeutic strategies against respiratory diseases.

Application of a Near-Infrared Fluorescence Probe Based on Perylene Bisimide in the Detection of Heparin.

Heparin is widely used to treat thrombosis because it is an effective anticoagulant. However, excessive use of heparin can lead to an increased risk of bleeding, which makes the quantitative detection of heparin very important. An amphiphilic perylene bisimide molecule (denoted PBI-9) was developed, which presented a near-infrared emission peak at 730 nm when it was aggregated. PBI-9 has been utilized in the detection of heparin, as the pyridine cation in PBI-9 binds strongly to highly sulfated heparin through electrostatic interactions. Charge neutralization triggers the self-assembly of PBI-9, which leads to an emission peak shift from 540 nm to 690 nm, corresponding to monomeric emission to excimer emission. This shift was applied for the detection of heparin. Importantly, the interaction between PBI-9 and heparin is not affected by protamine, resulting in high selectivity and minimal interference. PBI-9 is a promising tool for detecting heparin in clinical settings after excess heparin has been neutralized by protamine.

Alkyne‐ and Azide‐Functionalised Cyclophellitol Derivatives for Selective Glucuronidase Targeting

AbstractHeparanase is an endo‐acting β‐glucuronidase responsible for the degradation of heparan sulfate structures in the extracellular matrix. The enzyme is found to be significantly upregulated in aggressive cancer types, aiding cell proliferation by liberation of growth factors, increasing angiogenesis and metastasis. Despite much interest in the development of inhibitors to control this activity, no compound targeting heparanase has yet been approved as a drug. While mechanism‐based inhibitors derived from the natural product cyclophellitol are very potent enzyme inactivators through their reactive epoxide, one challenge in their development is in achieving selectivity for heparanase over related glycosidases while also maintaining a balance of appropriate pharmacological properties. We present here the synthesis of three cyclophellitol scaffolds presenting azide and alkyne handles at key positions, which are amenable to facile elaboration via copper‐catalysed azide‐alkyne cycloadditions to aid in exploring the structure‐activity relationship for selective inhibitors of heparanase.

Enhancing intrinsic TGF-β signaling via heparan sulfate glycosaminoglycan regulation to promote mesenchymal stem cell capabilities and chondrogenesis for cartilage repair

Osteoarthritis burdens patients due to the limited regenerative capacity of chondrocytes. Traditional cartilage repair often falls short, necessitating innovative approaches. Mesenchymal stem cells (MSCs) show promise for regeneration. Heparan sulfate glycosaminoglycans (HS-GAGs) regulate cellular functions, making them a target for cartilage repair. This study highlights how Heparinase III (HepIII) cleaves intact HS-GAGs in bone marrow-derived MSCs (BM-MSCs), enhancing their capabilities and specifically promoting chondrogenesis. HepIII-treated BM-MSCs cultured in a hanging drop device for three days, significantly increased cell number and aggregation into a cell sphere with early chondrogenesis. HepIII promoted BM-MSCs toward chondrogenesis, increasing type II collagen, intact HS-GAGs, and sulfated GAG content, while upregulating chondrogenic and heparan sulfate proteoglycan genes. Treatment with the TGF-β inhibitor (SB-431542) in HepIII-treated BM-MSCs demonstrated enhanced intrinsic transforming growth factor-β (TGF-β) signaling and fibronectin expression. This approach also boosted BM-MSC self-renewal, immunosuppressive potential, and modified acetylated histone signatures, offering a cost-effective strategy for cartilage repair by addressing inflammation, metabolic changes, and the high costs of traditional TGF-β methods. From the results, HepIII-treated BM-MSCs show potential for use in combination with other biopolymers as injectable gels to improve cartilage repair in osteoarthritis patients in the near future.

Hippocampal CA2 neurons disproportionately express AAV-delivered genetic cargo.

Hippocampal area CA2 is unique in many ways, largely based on the complement of genes expressed there. We and others have observed that CA2 neurons exhibit a uniquely robust tropism for adeno-associated viruses (AAVs) of multiple serotypes and variants. In this study, we aimed to systematically investigate the propensity for AAV tropism toward CA2 across a wide range of AAV serotypes and variants, injected either intrahippocampally or systemically, including AAV1, 2, 5, 6, 8, 9, DJ, PHP.B, PHP.eB, and CAP-B10. We found that most serotypes and variants produced disproportionally high expression of AAV-delivered genetic material in hippocampal area CA2, although two serotypes (AAV6 and DJ) did not. In an effort to understand the mechanism(s) behind this observation, we considered perineuronal nets (PNNs) that ensheathe CA2 pyramidal cells and, among other functions, buffer diffusion of ions and molecules. We hypothesized that PNNs might attract AAV particles and maintain them in close proximity to CA2 neurons, thereby increasing exposure to AAV particles. However, genetic deletion of PNNs from CA2 had no effect on AAV transduction. Next, we next considered the AAV binding factors and receptors known to contribute to AAV transduction. We found that the AAV receptor (AAVR), which is critical to transduction, is abundantly expressed in CA2, and knockout of AAVR nearly abolished expression of AAV-delivered material by all serotypes tested. Additionally, we found CA2 enrichment of several cell-surface glycan receptors that AAV particles attach to before interacting with AAVR, including heparan sulfate proteoglycans, N-linked sialic acid and N-linked galactose. Indeed, CA2 showed the highest expression of AAVR and the investigated glycan receptors within the hippocampus. We conclude that CA2 neurons are endowed with multiple factors that make it highly susceptible to AAV transduction, particularly to the systemically available PHP variants, including CAP-B10. Given the curved structure of hippocampus and the relatively small size of CA2, systemic delivery of engineered PHP or CAP variants could all but eliminate the need for intrahippocampal AAV injections, particularly when injecting recombinase-dependent AAVs into animals that express recombinases in CA2.

Heparan sulfate in cerebrospinal fluid as a biomarker to assess disease severity and for treatment monitoring in patients with Mucopolysaccharidosis Type II: a position statement.

Patients with mucopolysaccharidosis type II (MPS II) can present with a severe neuronopathic phenotype or an attenuated non-neuronopathic phenotype. In the light of the recent development of drugs that cross the blood-brain barrier for treatment of neurologic MPS II symptoms, it is critical to define biomarkers that objectively differentiate phenotypes and monitor therapeutic outcomes of advanced treatments. In December 2023, a panel of Brazilian experts discussed the potential of quantifying heparan sulfate (HS) in the cerebrospinal fluid (CSF) as a biomarker for assessing neurological impairment in patients with MPS II, as well as the potential of the molecule as an objective parameter for therapeutic monitoring. Based on scientific evidence, the experts concluded that HS in CSF is predominantly derived from the brain and reflects neurological impairment in patients with MPS II. CSF HS levels may help differentiate between neuronopathic and non-neuronopathic forms of MPS II, with preliminary observations suggesting a potential threshold around 4,000 ng/mL when HS quantification is performed using the same method described in clinical studies of pabinafusp alfa. According to the authors, monitoring HS levels in CSF can serve as an objective parameter for assessing the effectiveness of treatment with drugs that cross the blood-brain barrier. The recommended timing of HS evaluations in CSF of patients with the severe phenotype is: (i) before treatment; (ii) six months after starting treatment; and (iii) two years after starting treatment. The same monitoring scheme is recommended for patients with the attenuated MPS II phenotype, however, after two years of treatment, the physician may elect to perform regular neurocognitive evaluations instead of measuring HS in CSF. Lastly, the authors reinforced the importance of evaluating adherence to treatment, including interruptions, to provide a more meaningful assessment of the treatment's real-world impact and to determine the ideal timing of CSF collection for therapeutic monitoring.

Heparanase 2 Modulation Inhibits HSV-2 Replication by Regulating Heparan Sulfate

The host enzyme heparanase (HPSE) facilitates the release of herpes simplex virus type 2 (HSV-2) from target cells by cleaving the viral attachment receptor heparan sulfate (HS) from infected cell surfaces. HPSE 2, an isoform of HPSE, binds to but does not possess the enzymatic activity needed to cleave cell surface HS. Our study demonstrates that HSV-2 infection significantly elevates HPSE 2 protein levels, impacting two distinct stages of viral replication. We show that higher HPSE 2 negatively affects HSV-2 replication which may be through the regulation of cell surface HS. By acting as a competitive inhibitor of HPSE, HPSE 2 may be interfering with HPSE’s interactions with HS. We demonstrate that the enhanced expression of HPSE 2, either via viral infection or plasmid transfection, reduces HPSE’s ability to cleave HS, thereby hindering viral egress. Conversely, low HPSE 2 levels achieved through siRNA transfection allow HPSE to cleave more HS, reducing viral entry. Altogether, we propose a hypothetical model in which the modulation of HPSE 2 impedes HSV-2 replication by regulating HS availability on the cell surface. This dual role of HPSE 2 in viral replication and potential tumor suppression underscores its significance in cellular processes and viral pathogenesis.

Correlation of Hyaluronic Acid (HA), Syndecan-1 (SDC-1), Heparan Sulfate (HS) with early stage ad organ dysfunction in sepsis patients

This study aimed to explore the relationship between the changes in early degradation products of polysaccharide coatings (such as hyaluronic acid (HA), syndecan-1 (SDC-1), and heparan sulfate (HS)) and the development of organ dysfunction in sepsis patients. We conducted a retrospective analysis on 140 sepsis patients admitted from January 2021 to June 2022, who formed the study group; 100 healthy individuals who underwent health checks during the same period were included as the control group. The study found that the expression levels of HA, SDC-1, and HS upon admission and within 24 hours of admission in sepsis patients, as well as the early change rates, were positively correlated with organ dysfunction (P < 0.05). Through receiver operating characteristic (ROC) curve analysis, we discovered that the early change rates of HA, SDC-1, and HS have high predictive value for organ dysfunction in sepsis patients, with the combined predictive value being the most significant. The study conclusion points out that the increased levels of HA, SDC-1, HS, and other degradation products of polysaccharide coatings in the early stage of sepsis are positively associated with the occurrence of organ dysfunction. Clinicians can utilize the early expression changes of these biomarkers to predict the risk of organ dysfunction in sepsis patients, enabling timely implementation of preventive measures that may improve patient outcomes.

The effects of WWP1 overexpression on the golgi apparatus stress response and proteoglycan production in adipocytes

White adipocytes are a major component of white adipose tissue (WAT) and help to maintain systemic metabolic homeostasis by storing energy and secreting adipokines. In mice deficient in the protein WWP1 (WW domain-containing E3 ubiquitin protein ligase 1), oxidative stress in adipocytes increases but insulin resistance induced by obesity improves. However, the specific roles of WWP1 in adipocytes remain unclear. Here, we show that in 3T3L1 adipocytes, WWP1 localized in the Golgi apparatus via its C2 domain, where it protected the Golgi apparatus from monensin-induced disruption. By contrast, WWP1 knockdown by short hairpin RNA failed to protect the Golgi apparatus and enhanced Golgi apparatus disruption by monensin. The Golgi apparatus acts as a central organelle to establish accurate protein glycosylation of proteoglycans containing glycosaminoglycans, including chondroitin sulfate and heparan sulfate (HS). WWP1 overexpression increased chondroitin sulfate and HS levels, whereas WWP1 knockdown decreased them. Furthermore, obesity-related increases in HS were prevented by WWP1 knockout in adipose tissue. In summary, our results demonstrate a novel role for WWP1 in maintaining Golgi apparatus morphology and proteoglycan synthesis in adipocytes.

Glycan-induced structural activation softens the human papillomavirus capsid for entry through reduction of intercapsomere flexibility

High-risk human papillomaviruses (HPVs) cause various cancers. While type-specific prophylactic vaccines are available, additional anti-viral strategies are highly desirable. Initial HPV cell entry involves receptor-switching induced by structural capsid modifications. These modifications are initiated by interactions with cellular heparan sulphates (HS), however, their molecular nature and functional consequences remain elusive. Combining virological assays with hydrogen/deuterium exchange mass spectrometry, and atomic force microscopy, we investigate the effect of capsid-HS binding and structural activation. We show how HS-induced structural activation requires a minimal HS-chain length and simultaneous engagement of several binding sites by a single HS molecule. This engagement introduces a pincer-like force that stabilizes the capsid in a conformation with extended capsomer linkers. It results in capsid enlargement and softening, thereby likely facilitating L1 proteolytic cleavage and subsequent L2-externalization, as needed for cell entry. Our data supports the further devising of prophylactic strategies against HPV infections.

The co-receptor Tetraspanin12 directly captures Norrin to promote ligand-specific β-catenin signaling.

Wnt/β-catenin signaling directs animal development and tissue renewal in a tightly controlled, cell- and tissue- specific manner. In the mammalian central nervous system, the atypical ligand Norrin controls angiogenesis and maintenance of the blood-brain barrier and blood-retina barrier through the Wnt/β-catenin pathway. Like Wnt, Norrin activates signaling by binding and heterodimerizing the receptors Frizzled (Fzd) and Low-density lipoprotein receptor-related protein 5 or 6 (LRP5/6), leading to membrane recruitment of the intracellular transducer Dishevelled (Dvl) and ultimately stabilizing the transcriptional coactivator β-catenin. Unlike Wnt, the cystine-knot ligand Norrin only signals through Fzd4 and additionally requires the co-receptor Tetraspanin12 (Tspan12); however, the mechanism underlying Tspan12-mediated signal enhancement is unclear. It has been proposed that Tspan12 integrates into the Norrin-Fzd4 complex to enhance Norrin-Fzd4 affinity or otherwise allosterically modulate Fzd4 signaling. Here, we measure direct, high-affinity binding between purified Norrin and Tspan12 in a lipid environment and use AlphaFold models to interrogate this interaction interface. We find that Tspan12 and Fzd4 can simultaneously bind Norrin and that a pre-formed Tspan12/Fzd4 heterodimer, as well as cells co-expressing Tspan12 and Fzd4, more efficiently capture low concentrations of Norrin than Fzd4 alone. We also show that Tspan12 competes with both heparan sulfate proteoglycans and LRP6 for Norrin binding and that Tspan12 does not impact Fzd4-Dvl affinity in the presence or absence of Norrin. Our findings suggest that Tspan12 does not allosterically enhance Fzd4 binding to Norrin or Dvl, but instead functions to directly capture Norrin upstream of signaling.

Computational investigation of missense somatic mutations in cancer and potential links to pH-dependence and proteostasis.

Metabolic changes during tumour development lead to acidification of the extracellular environment and a smaller increase of intracellular pH. Searches for somatic missense mutations that could reveal adaptation to altered pH have focussed on arginine to histidine changes, part of a general arginine depletion that originates from DNA mutational mechanisms. Analysis of mutations to histidine, potentially a simple route to the introduction of pH-sensing, shows no clear biophysical separation overall of subsets that are more and less frequently mutated in cancer genomes. Within the more frequently mutated subset, individual sites predicted to mediate pH-dependence upon mutation include NDST1 (a Golgi-resident heparan sulphate modifying enzyme), the HLA-C chain of MHCI complex, and the water channel AQP-7. Arginine depletion is a general feature that persists in the more frequently mutated subset, and is complemented by over-representation of mutations to lysine. Arginine to lysine balance is a known factor in determining protein solubility, with higher lysine content being more favourable. Proteins with greater change in arginine to lysine balance are enriched for cell periphery location, where proteostasis is likely to be challenged in tumour cells. Somatic missense mutations in a cancer genome number only in the 10s typically, although can be much higher. Whether the altered arginine to lysine balance is of sufficient scale to play a role in tumour development is unknown.

Feasibility assessment of using cRISPR-Cas9 to improve the infiltration of CAR-T cells in solid tumors

Abstract. Chimeric antigen receptor T-cell immunotherapy (CAR-T) has been developing for decades, CAR-T is playing an increasingly important role in tumor treatment. However, because fibroblasts (CAFs) in solid tumors secrete proteins and glycans to form ECM, CAR-T is faced with the challenge of improving tumor invasion. To this end, a new scheme was put forth to alter CAR T cells such that they release heparinase (HPSE) to break down heparan sulfate proteoglycan (HSPG), which is covered on the outermost layer of the cancerous cells by CAF and released. In order to solve the above problems, CRISPR-Cas9 was proposed to modify CAR T to enhance the secretion of HPSE. Although this method has the advantage of broad spectrum, it still has certain defects. The matrix characteristics of different solid tumors and the subpopulations and regulatory mechanisms of HPSE need to be further studied. The off-target effects of CRISPR-Cas9 gene editing technology and the high cost and time-consuming problems of flow cytometry also limit its application. It is anticipated to enhance cell infiltration in solid tumors, boost CAR-T therapy's effectiveness in treating solid tumors, and advance the field of CAR-T therapy.

The potential of lactoferrin as antiviral and immune-modulating agent in viral infectious diseases.

Emerging infectious diseases are caused by unpredictable viruses with the dangerous potential to trigger global pandemics. These viruses typically initiate infection by utilizing the anionic structures of host cell surface receptors to gain entry. Lactoferrin (Lf) is a multifunctional glycoprotein with multiple properties such as antiviral, anti-inflammatory and antioxidant activities. Due to its cationic structure, Lf naturally interacts with certain host cell receptors, such as heparan sulfate proteoglycans, as well as viral particles and other receptors that are targeted by viruses. Therefore, Lf may interfere with virus-host cell interactions by acting as a receptor competitor for viruses. Herein we summarize studies in which this competition was investigated with SARS-CoV-2, Zika, Dengue, Hepatitis and Influenza viruses in vitro. These studies have demonstrated not only Lf's competitive properties, but also its potential intracellular impact on host cells, such as enhancing cell survival and reducing infection efficiency by inhibiting certain viral enzymes. In addition, the immunomodulatory effect of Lf is highlighted, as it can influence the activity of specific immune cells and regulate cytokine release, thereby enhancing the host's response to viral infections. Collectively, these properties promote the potential of Lf as a promising candidate for research in viral infectious diseases.

High-throughput glycosaminoglycan extraction and UHPLC-MS/MS quantification in human biofluids.

Glycosaminoglycans (GAGs) are linear, unbranched heteropolysaccharides whose structural complexity determines their function. Accurate quantification of GAGs in biofluids at high throughput is relevant for numerous biomedical applications. However, because of the structural variability of GAGs in biofluids, existing protocols require complex pre-analytical procedures, have limited throughput and lack accuracy. Here, we describe the extraction and quantification of GAGs by using ultra-high-performance liquid chromatography coupled with triple-quadrupole mass spectrometry (UHPLC-MS/MS). Designed for 96-well plates, this method enables the processing of up to 82 study samples per plate, with the remaining 14 wells used for calibrators and controls. Key steps include the enzymatic depolymerization of GAGs, their derivatization with 2-aminoacridone and their quantification via UHPLC-MS/MS. Each plate can be analyzed in a single UHPLC-MS/MS run, offering the quantitative and scalable analysis of 17 disaccharides from chondroitin sulfate, heparan sulfate and hyaluronic acid, with a level of precision and reproducibility sufficient for their use as biomarkers. The procedure from sample thawing to initiating the UHPLC-MS/MS run can be completed in ~1.5 d plus 15 min of MS runtime per sample, and it is structured to fit within ordinary working shifts, thus making it a valuable tool for clinical laboratories seeking high-throughput analysis of GAGs. The protocol requires expertise in UHPLC-MS/MS.

Abstract A005: Microbind affinity blood filter platform technology with affinity for heparan sulfate rapidly removes circulating epithelial tumor and cancer stem cells while downregulating VEGF A in patients with advanced and refractory solid tumors

Abstract Background: Vascular endothelial-derived growth factor A(VEGFA) has been proven to be integral in the molecular pathogenesis of metastasis and tumor growth. It is known that VEGF is responsible for encoding a heparin-binding protein, which exists as a disulfide-linked homodimer which serves to promote the propagation and movement of vascular endothelial cells. This is essential for both pathological and physiological angiogenesis. CETC and cancer stem cells are potent secretors of VEGFA which is an essential cytokine that facilitates new vascular vessel formation, thus further enabling metastatic tumor growth. Methods: We developed a new extracorporeal microbind affinity blood filter platform technology with active heparane sulfate receptors (onco seraph). Heparin is cleaved into short chains which are permanently covalently bound to ultrahigh molecular weight polyethylene (UHMWPE) surfaces to create a new composition of matter. Liquid biopsy established high capacity for the rapid removal of CETC and PDAC cancer stem cells. Onco seraph was investigated in a dose escalation phase I/II clinical trial in adult patients with advanced and relapsed/refractory solid (what) and/or PDAC after standard of care and other lines of therapy failed in preventing disease progression. Results: To date 12 patients have been treated with onco seraph. No patient experienced treatment related adverse effects. Best responses include complete responses and stable disease at a low oncoseraph dose. Greatest efficacy was observed for patients whose liquid biopsy revealed significant and rapid reduction of CETC and cancer stem cells, followed by greater than 50% reduction in circulating VEGFA. Conclusions: This data supports the conclusion that the onco seraph platform technology is safe and has a high therapeutic value as an extracorporeal treatment for metastatic solid tumors refractory to standard of care. Citation Format: Sanja ILIC, Vedran Premuzic, Robert Ward. Microbind affinity blood filter platform technology with affinity for heparan sulfate rapidly removes circulating epithelial tumor and cancer stem cells while downregulating VEGF A in patients with advanced and refractory solid tumors [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A005.