Search Results (398)

Heparan sulfate proteoglycans (HSPGs) within the neuronal niche are expressed during brain development, contributing to multiple aspects of neurogenesis, yet their roles in glial lineage commitment remain elusive. This study utilised three human cell models expanded under basal culture conditions followed by media-induced lineage induction to identify a reproducible and robust model of gliogenesis. SH-SY5Y human neuroblastoma cells (neuronal control), ReNcell CX human neural progenitor cells (astrocyte inductive) and ReNcell VM human neural progenitor (mixed neural induction) models were examined. The cultures were characterised during basal and inductive states via Q-PCR, Western Blotting, immunocytochemistry (ICC) and calcium signalling activity analyses. While the ReNcell lines did not produce fully mature or homogeneous astrocyte cultures, the ReNcell CX cultures most closely resembled an astrocytic phenotype with ReNcell VM cells treated with platelet-derived growth factor (PDGF) biased toward an oligodendrocyte lineage. The glycated variant of surface-bound glypican-2 (GPC2) was found to be associated with lineage commitment, with GPC6 and 6-O HS sulfation upregulated in astrocyte lineage cultures. Syndecan-3 (SDC3) emerged as a lineage-sensitive proteoglycan, with its cytoplasmic domain enriched in progenitor-like states and lost upon differentiation, supporting a role in maintaining neural plasticity. Conversely, the persistence of transmembrane-bound SDC3 in astrocyte cultures suggest continued involvement in extracellular signalling and proteoglycan secretion, demonstrated by increased membrane-bound HS aggregates. This data supports HSPGs and HS GAGs as human neural lineage differentiation and specification markers that may enable better isolation of human neural lineage-specific cell populations and improve our understanding of human neurogenesis. Full article

Heparin and heparan sulfate are essential in various biological processes relevant to cancer biology and pathology. Given the clinical importance of breast cancer, it is of high interest to seek more effective and safer treatment. The application of heparins (UFH, LMWH, ULMWH, fondaparinux) and heparin mimetics as potential treatments is particularly interesting. Their use led to promising results in various breast cancer models by exhibiting anti-angiogenic and anti-metastatic properties. This article concisely reviews studies involving heparins and mimetics in both in vitro and in vivo breast cancer settings. We highlight molecules, conjugates, delivery systems, and combinations involving heparin or its mimetics. We also survey several potential biological targets such as VEGF, FGF-2, TGFβ-1, PDGF-B, NPP-1, CXCL12-CXCR4 axis, and CCR7-CCL21 axis. Overall, heparins and their mimetics, conjugates, and combinations represent a powerful strategy to effectively and safely treat breast cancer, which is the most common cancer diagnosed in women worldwide and the fifth leading cause of cancer-related deaths worldwide. Full article

The endothelial glycocalyx (GCX) plays a crucial role in vascular health and integrity and influences many biochemical activities through mechanotransduction, in which heparan sulfate (HS) plays a major role. Endothelin-1 (ET-1) is a potent vasoregulator that binds to the endothelin B receptor (ETB) on endothelial cells (ECs), stimulating vasodilation, and to the endothelin A receptor on smooth muscle cells, stimulating vasoconstriction. While the shear stress (SS) dependence of ET-1 and HS is well documented, there is limited research documenting the SS dependence of the ETB. Understanding the SS dependence of the ETB is crucial for clarifying the role of hemodynamic forces in the endothelin system. We hypothesize that GCX HS regulates the expression of the ETB on the EC surface in an SS-dependent manner. Human lung microvascular ECs were exposed to SS in a parallel-plate flow chamber for 12 h. Damage to the GCX was simulated by treatment with 15 mU/mL heparinase-III during SS exposure. Immunostaining and qPCR were used to evaluate changes in ET-1, ETB, and HS expression. Results indicate that ETB expression is SS sensitive, with at least a 1.3-fold increase in ETB protein expression and a 0.6 to 0.4-fold-change decrease in ETB mRNA expression under SS. This discrepancy suggests post-translational regulation. In some cases, enzymatic degradation of HS attenuated the SS-induced increase in ETB protein, reducing the fold-change difference to 1.1 relative to static controls. This implies that ETB expression may be partially dependent on HS-mediated mechanotransduction, though inconclusively. Furthermore, ET-1 mRNA levels were elevated two-fold under SS without a corresponding rise in ET-1 protein expression or significant impact from HS degradation, implying that post-translational regulation of ET-1 occurs independently of HS. Full article

Background: Heparan sulfate (HS) is widely implicated as a receptor for Chlamydia cell attachment and infectivity. However, the enzymatic modification of HS modified by the 3-O sulfotransferase-3 (3-OST-3) enzyme in chlamydial cell entry remains unknown. Methodology: To rule out the possibility that host cell 3-O sulfated heparan sulfate (3-OS HS) plays a significant role in C. muridarum entry, a Chinese hamster ovary (CHO-K1) cell model lacking endogenous 3-OST-3 was used. In addition, we further tested the efficacy of the phage-display-derived cationic peptides recognizing heparan sulfate (G1 peptide) and the moieties of 3-O sulfated heparan sulfate (G2 peptide) against C. muridarum entry using human cervical adenocarcinoma (HeLa 229) and human vaginal epithelial (VK2/E6E7) cell lines. Furthermore, molecular dynamics simulations were conducted to investigate the interactions of the Chlamydia lipid bilayer membrane with the G1 and G2 peptides, focusing on their binding modes and affinities. Results: The converse effect of 3-OST-3 expression in the CHO-K1 cells had no enhancing effect on C. muridarum entry. The G2 peptide significantly (>80%) affected the cell infectivity of the elementary bodies (EBs) at all the tested concentrations, as evident from the reduced fluorescent staining in the number of inclusion bodies. The observed neutralization effect of G2 peptide on C. muridarum entry suggests the possibility of sulfated-like domains being present on the EBs. In addition, data generated from our in silico computational structural modeling indicated that the G2 peptide ligand had significant affinity towards the C. muridarum lipid bilayer. Conclusions: Taken together, our findings show that the pretreatment of C. muridarum with 3-O sulfated heparan sulfate recognizing G2 peptide significantly prevents the entry of EBs into host cells. Full article

Syndecan-3 (SDC3), a transmembrane heparan sulfate proteoglycan involved in cell signaling and endocytosis, has recently been implicated in the pathogenesis of neurodegenerative disorders. While preclinical studies have demonstrated its role in Alzheimer’s disease (AD), its diagnostic relevance in peripheral blood remains unexplored. In this human cohort study, we measured SDC3 expression in peripheral blood mononuclear cells (PBMCs) from 22 clinically diagnosed AD patients and 20 cognitively unimpaired non-AD controls using a custom ELISA. The findings were compared with plasma p-tau217 levels and a panel of systemic laboratory markers. PBMC-expressed SDC3 was significantly elevated in AD patients and moderately correlated with AD status (r = 0.309, p = 0.0465) independent of age. Notably, SDC3 levels were inversely correlated with systemic inflammatory markers, including C-reactive protein (CRP; r = −0.421, p = 0.0055) and D-dimer (r = −0.343, p = 0.038), suggesting an AD-associated immune phenotype distinct from acute-phase or vascular inflammation. Conversely, plasma p-tau217 levels did not significantly differ between groups but correlated with markers of tissue injury and inflammation (LDH, GOT, and ferritin), potentially reflecting systemic influences in non-AD controls. A multivariable logistic regression model incorporating SDC3, p-tau217, and age demonstrated high diagnostic accuracy (AUC = 0.85). These findings identify PBMC-expressed SDC3 as a promising blood-based biomarker candidate for AD, warranting further validation in larger, biomarker-confirmed cohorts. Full article

Background: The COVID-19 (coronavirus disease 19) pandemic has underscored the urgent need for effective antiviral agents targeting viral entry mechanisms. This study investigated the inhibitory effects of heparan sulfate (HS) and enoxaparin (EX) on the interaction between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and the angiotensin-converting enzyme 2 (ACE2) receptor. Methods: A pseudovirus model was employed to evaluate the efficacy of HS and EX under different treatment strategies: pre-treatment of host cells, pre-treatment of the viral particles, and simultaneous co-treatment. Results: Both compounds significantly inhibited viral entry. EX exhibited a dose-dependent effect under all treatment conditions. In cell pre-treatment, EX achieved the highest levels of inhibition, whereas HS demonstrated consistent inhibitory activity that was largely concentration-independent. Viral pre-treatment revealed that both compounds effectively reduced infectivity by interfering directly with viral particles. In the co-treatment experiments, HS demonstrated superior inhibitory activity at lower concentrations compared to EX. Conclusions: The results suggested that HS and EX inhibit SARS-CoV-2 entry via distinct mechanisms. HS likely acts via competitive inhibition at the host cell surface, while EX may bind directly to the spike protein, thereby preventing engagement with the ACE2 receptor. These findings highlight the therapeutic potential of HS and EX as entry inhibitors targeting the early stages of SARS-CoV-2 infection. Further studies are warranted to evaluate their efficacy against emerging variants and in vivo models. Full article

Background/Objectives: Endplate lesions of the lumbar spine are often asymptomatic and frequently observed incidentally by radiological assessment. Variants in the vitamin D receptor gene (VDR) and an increase in some biochemical markers related to the osteo-cartilaginous metabolism were found in patients with endplate lesions. The aim of this study was to identify biochemical and genetic markers putatively associated with the presence of endplate lesions of the lumbar spine. Methods: Quantification of circulating bone remodeling proteins was obtained from 10 patients with endplate lesions and compared with age- and sex-matched controls. Whole exome sequencing (WES) was performed on patient genomic DNA using the Novaseq 6000 platform (Illumina, San Diego, CA, USA), obtaining a median read depth of 117×–200×, with ≥98% of regions covering at least 20×. The sequencing product was aligned to the reference genome (GRCh38.p13-hg38) and analyzed with Geneyx software. Results: We observed modifications in the levels of circulating proteins involved in bone remodeling and angiogenesis. We identified variants of interest in aggrecan (ACAN), bone morphogenetic protein 4 (BMP4), cytochrome P450 family 3 subfamily A member 4 (CYP3A4), GLI family zinc finger 2 (GLI2), heparan sulfate proteoglycan 2 (HSPG2), and mesoderm posterior bHLH transcription factor 2 (MESP2). VDR polymorphism (rs2228570) was present in nine patients, with the homozygotic ones having more severe endplate lesions and higher levels of the analyzed circulating markers in comparison with heterozygotic patients. Conclusions: These data represent interesting evidence of genetic variants, particularly in VDR, and altered levels of circulating markers of bone remodeling associated with endplate lesions, which should be confirmed in a larger population. The hypothesis suggested by our results is that the endplate lesions could be the consequence of an altered ossification mechanism at the vertebral level. Full article

Surface plasmon resonance (SPR) is a powerful tool for analyzing biomolecular interactions and is widely used in basic biomedical research and drug discovery. Heparan sulfate (HS) is a linear complex polysaccharide and a key component of the extracellular matrix and cell surfaces. HS plays a pivotal role in maintaining cellular functions and tissue homeostasis by interacting with numerous proteins, making it essential for normal physiological processes and disease states. Deciphering the interactome of HS unlocks the mechanisms underlying its biological functions and the potential for novel HS-related therapeutics. This review presents an overview of the recent advances in the application of SPR technology to HS interactome research. We discuss methodological developments, emerging trends, and key findings that illustrate how SPR is expanding our knowledge of HS-mediated molecular interactions. Additionally, we highlight the potential of SPR-based approaches in identifying novel therapeutic targets and developing HS-mimetic drugs, thereby opening new avenues for intervention in HS-related diseases. Full article

Abnormal deposition of β-amyloid (Aβ) is a core pathological feature of Alzheimer’s disease (AD). Syndecan-3 (SDC3), a type I transmembrane heparan sulfate proteoglycan (HSPG), is abnormally overexpressed in the brains of AD patients and model animals, specifically accumulating in the peri-plaque region of amyloid plaques. However, its regulatory mechanism in the process of Aβ deposition remains unclear. This study aims to clearly define the role of SDC3 in Aβ aggregation and neuroinflammation, two critical processes in AD pathogenesis. Specifically, we investigate how SDC3 modulates Aβ aggregation and its interaction with neuroinflammatory pathways, which may contribute to the progression of AD. By elucidating the mechanisms underlying SDC3’s involvement in these processes, we seek to provide new insights into potential therapeutic targets for AD. In this study, a 5×FAD mouse model with downregulated SDC3 expression was constructed. Behavioral assessments and synaptic function tests were performed to explore the effects of SDC3 on cognition in 5×FAD mice. Immunofluorescence co-localization technology was utilized to analyze the pathological co-deposition of SDC3 and Aβ in the hippocampus, cortex, and meningeal blood vessels. Quantitative assessments of pro-inflammatory cytokines such as Tnf-α and Cxcl10 in the brain were performed through histopathological analysis combined with qPCR. Western blotting was used to examine the phosphorylation status of STAT1/STAT3 and the expression changes of IBA1/GFAP to systematically analyze the molecular mechanisms through which SDC3 regulates AD pathology. This study revealed that SDC3 expression was significantly upregulated in the brain regions of the 5×FAD model mice and co-localized pathologically with Aβ. Cell lineage tracing analysis showed that the elevated SDC3 expression primarily originated from glial cells. Behavioral and pathological results demonstrated that downregulation of SDC3 significantly improved cognitive dysfunction in the model mice and effectively reduced the Aβ burden in the brain. Molecular mechanism studies showed that downregulation of SDC3 reduced the phosphorylation of STAT1 and STAT3, thereby inhibiting the activation of the JAK-STAT and cGAS-STING signaling pathways, reducing the activation of microglia/astrocytes and suppressing the expression of pro-inflammatory cytokines such as Tnf-α and Cxcl10. This study reveals that SDC3 co-localizes with Aβ pathology and synergistically exacerbates neuroinflammation. Knockdown of SDC3 can simultaneously reduce both Aβ deposition and the release of inflammatory factors from glial cells. Mechanistic research indicates that SDC3 drives a “glial activation–cytokine release” vicious cycle through the JAK-STAT and cGAS-STING signaling pathways. These findings suggest that SDC3 may serve as a key hub coordinating amyloid pathology and neuroinflammation in AD, providing new insights for the development of combination therapies targeting the HSPG network. Full article

VE-cadherin (VE-cad) membrane stability and localization regulates adhesion formation and actin cytoskeleton dynamics in angiogenesis and vascular remodeling and requires the heparan sulfate proteoglycan (HSPG), Syndecan-4 (Sdc4). This study characterizes the interactions of the heparin receptor, Transmembrane protein-184A (TMEM184A), and Sdc4 in bovine aortic endothelial cells (BAOECs) and the regenerating Zebrafish (ZF) caudal fin and measures the effect of siRNA TMEM184A KD (siTMEM) and TMEM184A overexpression (TMEM OE) on VE-cad levels and localization in confluent and sub-confluent cultured BAOECs. Additionally, we examined the effect of siTMEM on key Rab GTPase trafficking regulators and migrating BAOECs in scratch wound healing assays. We demonstrated that TMEM184A and Sdc4 colocalize in BAOECs and that Sdc4 OE increases colocalization in an HS chain dependent manner, while both Tmem184a and Sdc4 cooperate synergistically in ZF fin angiogenic and tissue repair. We also showed that siTMEM decreases VE-cad membrane and cytoplasmic levels, while increasing scratch wound migration rates. However, TMEM OE cells show increased vesicle formation and VE-cad trafficking and membrane recovery. These findings characterize TMEM184A-Sdc4 cooperation in angiogenesis and indicate a dual function of TMEM184A in signaling and trafficking in vascular cells that promotes VE-cad recovery and membrane localization. Full article

Pathogenic bacteria of the genus Leptospira are the etiological agents of leptospirosis, a disease that affects humans and animals worldwide. Despite the increasing number of studies, the mechanisms of leptospiral pathogenesis remain poorly comprehended. In this study, we report various interactions of the LigA7’-13’ and LigB1’-7’ domains with host components. The LigA7’-13’ and LigB1’-7’ were cloned into the pET28a vector, and the recombinant proteins were expressed in E. coli C43 (DE3) and E. coli BL21 (DE3), respectively. Both recombinant protein domains were expressed in soluble form and purified using nickel-chelating chromatography. The rLigA7’-13’ and rLigB1’-7’ domains exhibited binding to several types of integrins, with most interactions occurring in a dose-dependent and saturable manner, consistent with the characteristics of typical receptor-ligand interactions. The recombinant domain LigA7’-13’ demonstrated affinity for the glycosaminoglycans (GAGs) chondroitin-4-sulfate, chondroitin sulfate, heparin, chondroitin sulfate B, and heparan sulfate, while no binding was detected for LigB1’-7’ with these molecules. Both rLigA7’-13’ and rLigB1’-7’ interacted with components of the terminal complement pathway and were capable of recruiting C9 from normal human serum (NHS). These interactions may inhibit the formation of polyC9, ultimately preventing the assembly of the membrane attack complex (MAC). Collectively, our data expand the repertoire of host components that interact with rLigA7’-13’ and rLigB1’-7’, opening new avenues for understanding leptospiral immune evasion and broadening the roles of these domains in bacterial virulence. Full article

Axon guidance, a fundamental process in neural circuit formation, is intricately regulated by Fibroblast Growth Factors (FGFs) and their receptors (FGFRs) through dynamic cytoskeletal remodeling. FGF signaling, mediated by heparan sulfate proteoglycans or Klotho co-factors, activates key downstream pathways: PI3K-Akt, JAK-STAT, PLCγ, and RAS-MAPK. These pathways orchestrate actin filament dynamics, microtubule stability, and the organization of intermediate filaments. These pathways converge on Rho GTPases, cofilin, profilin, and tau to balance the cytoskeletal assembly−disassembly cycles, enabling growth cone navigation. Unresolved questions, such as the mechanisms underlying FGF-mediated growth cone steering, highlight critical future research directions. This review integrates structural, molecular, and functional insights into how FGF-FGFR interactions regulate axon pathfinding, emphasizing the crosstalk between signaling cascades and cytoskeletal plasticity. Elucidating these mechanisms not only advances our understanding of neural development but also opens therapeutic avenues for neuro-developmental disorders, nerve injury, and neurodegenerative diseases by targeting FGF-driven cytoskeletal dynamics. Full article

Heparan sulfate (HS) and chondroitin sulfate (CS) proteoglycans (PGs) are essential regulators of many biological processes including cell differentiation, signalization, and proliferation. PGs interact mainly via their glycosaminoglycan (GAG) chains, with a large number of ligands including growth factors, enzymes, and extracellular matrix components, thereby modulating their biological activities. HSPGs and CSPGs share a common tetrasaccharide linker region, which undergoes modifications, particularly the phosphorylation of the xylose residue by the kinase FAM20B. Here, we demonstrated that FAM20B gain-of-function decreased, in a dose dependent manner, the synthesis of both CS- and HS-attached PGs. In addition, we showed that blockage of GAG chain synthesis by FAM20B was suppressed by the mutation of aspartic acid residues D289 and D309 of the catalytic domain. Interestingly, we bring evidence that, in contrast to FAM20B, expression of the 2-phosphoxylose phosphatase XYLP increases, in a dose dependent manner, GAG chain synthesis and rescues the blockage of GAG chains synthesis induced by FAM20B. In line with previous reports, we found that FAM20B loss-of-function reduced GAG chain synthesis. Finally, we found that FAM20B inhibited proliferation and migration of glioblastoma cells, thus revealing the critical role of GAG chains of PGs in glioblastoma cell tumorigenesis. This study revealed that both gain- and loss-of-function of FAM20B led to decreased GAG chain synthesis, therefore suggesting that a balance between phosphorylation and dephosphorylation of the xylose by FAM20B and XYLP, respectively, is probably an essential factor for the regulation of the rate of PG synthesis. Full article

A precision genome edit in the bovine CD46 gene (A₈₂LPTFS₈₇) dramatically reduced bovine viral diarrhea virus (BVDV) susceptibility in a cloned heifer. However, pathogen evolution threatens the long-term efficacy of such interventions. Here, our aim is two-fold: first, to determine whether BVDV can adapt in vitro to use the edited CD46 receptor to infect Madin–Darby bovine kidney (MDBK) cells, and second, to evaluate the ex vivo infectivity of culture-adapted viruses in cells from the CD46-edited heifer. Serial passage of BVDV on CD46-edited MDBK cells selected for virus variants capable of CD46-independent infection. Virus genome sequencing revealed mutations in the viral E^RNS gene predicted to enhance HS-mediated entry. HS adaptation was confirmed by inhibiting virus infection with heparin or Heparinase I/III treatment. A naturally occurring HS-adapted field isolate from a persistently infected calf showed similar results. However, when tested on primary cells from the CD46-edited heifer, HS-adapted viruses showed reduced infectivity in skin fibroblasts, monocytes, and lymphocytes in a manner that correlated with HS expression. Thus, although BVDV can adapt to use HS as an alternative entry receptor, HS adaptation does not overcome the protection conferred by the CD46 edit in all relevant cell types. Full article

Inflammation of the exocrine pancreas accompanies autoimmune diabetes in mouse models and humans. However, the relationship between inflammation in the exocrine and endocrine (islet) compartments has not been explored. To address this issue, we used a transgenic mouse model in which autoimmune diabetes is acutely induced after the transfer of islet beta cell-specific transgenic T cells. Histological analyses demonstrated that inflammation of the exocrine pancreas, which was initially mild, resulted in the transient but widespread disruption of acinar tissue. Islet inflammation preceded exacerbated exocrine pathology, progressed to T cell-induced islet damage/destruction and persisted when exocrine inflammation subsided. Heparanase-1 (HPSE-1), an endoglycosidase that degrades heparan sulfate in basement membranes (BMs), when preferentially expressed in recipient cells but not donor (HPSE-1-deficient (HPSE-KO)) T cells, played a critical role in both exocrine and islet inflammation. In this context, HPSE-1 facilitates the passage of autoimmune T cells across the sub-endothelial basement membrane (BM) of pancreatic blood vessels and initially into the exocrine tissue. Peak exocrine inflammation that preceded or accompanied the acute onset of diabetes and HPSE-1 potentially contributed to acinar damage. In contrast to inflammation, HPSE-1 expressed by donor T cells played a key role in the induction of diabetes by allowing autoimmune T cells to traverse peri-islet BMs in order to destroy insulin-producing beta cells. Overall, our findings suggest that major exocrine pancreas injury is not required for the initiation of autoimmune islet damage and is not essential at the time of diabetes onset. Full article