bims-supasi 2025-12-07 papers

bims-supasi

Biomed News

on Sulfation pathways and signalling

Issue of 2025–12–07
fifteen papers selected by
Jonathan Wolf Mueller, University of Birmingham

A novel exo-lytic and disaccharide-yielding glycosaminoglycan lyase from a marine-derived polysaccharide-degrading actinobacterium Microbacterium sp. strain WS15.
Biomimetic Glycosaminoglycan Analog Hydrogels Inhibit Neurite Outgrowth While Supporting Neuronal Cell Viability.
Structurally defined synthetic heparin oligosaccharides reveal unique signatures for nanopore structural analysis of GAGs.
Spontaneous generation of diverse recombinant prion strains: sulfated glycan cofactors facilitate strain emergence but do not determine specific strain properties.
Effect of a chondroitin sulfate chain linked to the bikunin core peptide on gene expression in lipopolysaccharide-treated uterine cervical fibroblasts.
Bioinspired hydroxyapatite nanoparticle: Functionalization with chondroitin sulfate-thiol/amine moieties for synergistic bone tissue regeneration and oxidative stress mitigation.
Structural characterization of starch-like α-glucan from the seeds of Euryale ferox Salisb and evaluation on the anti-inflammatory activity after sulfated modification.
Indoxyl sulfate promoted glutamine metabolism and cell proliferation in urothelial carcinoma involving Runx2.
Spermidine-encapsulated chondroitin sulfate methacryloyl hydrogel delivery system for remodeling bone homeostasis in rheumatoid arthritis.
Seaweed polysaccharides and their potential health effects via gut microbiota modulation.
Influence of cationic species on β-agarase-mediated depolymerization of agarans.
Chondroitin sulfate proteoglycan 4 (CSPG4) overexpression as an oncogenic driver and prognostic marker for unfavorable outcomes in hepatocellular carcinoma.
Culturing hypoxia-primed mesenchymal stem cells in xeno- and serum-free conditions facilitates the synthesis of an extracellular matrix-based biologic with augmented therapeutic potential for the treatment of diabetic wounds.
Plasma membrane transbilayer asymmetry of PI(4,5)P2 drives unconventional secretion of Fibroblast Growth Factor 2.
Quantification of keratan sulfate in biofluids by validated HPCE-LIF: application to Morquio syndrome.

Front Microbiol. 2025 ;16 1680841

A novel exo-lytic and disaccharide-yielding glycosaminoglycan lyase from a marine-derived polysaccharide-degrading actinobacterium Microbacterium sp. strain WS15.

Peng Li, Zaichao Ma, Ruyi Zou, Jingyan Gu, Ningning Shan, Wenjun Han, Hailong Wang, Fuchuan Li, Haining Tan.

   Introduction: Glycosaminoglycan (GAG) lyases play key roles in preparing oligosaccharides, treating human diseases, and learning relationships between complex structures and various functions of carbohydrates. An endo-lytic enzyme will depolymerize GAGs randomly and finally produce a series of size-defined oligosaccharide fractions, whereas an exo-lytic lyase can usually yield the sole final oligosaccharide products. However, it is difficult to distinguish them directly depending on protein sequences, which limits further resource exploration.
Results and Dicussion: In this study, we initially isolated and identified a marine-derived polysaccharide-degrading actinobacterium, Microbacterium sp. strain WS15, and subsequently explored by genome sequencing and data mining, as a new candidate GAGs lyase within the eighth polysaccharide lyase (PL8) family, sharing high sequence identity with characterized endo-type GAG lyases. The recombinant proteins of TT16 were optimal at 50 °C and pH 7.0, respectively, and active against multiple polysaccharide substrates, including both unsulfated GAG (e.g., hyaluronate) and sulfated GAGs (e.g., chondroitin sulfate A-E types), implying a broad spectrum based on sulfation tolerance. However, TT16 was novel for predominantly yielding unsaturated disaccharides as an exo-type lyase, rather than an endo-type lyase, with the smallest substrate being associated with tetrasaccharides, suggesting the potential in disaccharide preparation. Comparative enzymatic analyses indicated that all the biochemical characteristics and catalytic properties were determined by the TT16 protein rather than the additional protein tag. Moreover, protein structure modeling followed by molecular docking revealed that protein TT16 showed low binding energies with various donors, and its catalytic cavity was large and flexible to accommodate either two unsulfated hyaluronate disaccharides or a chondroitin sulfate E (CSE) tetrasaccharide with four sulfate groups as a donor, implying a structural basis suitable for the disaccharide-yielding type. Furthermore, the motif of Tyr284, Asn225, and His275 also provided the catalytic basis for β-elimination, while residues Ala71 and Arg219 might be essential for the novel exo-lytic mode.
Significance: This study provided the protein TT16 as a novel exo-lytic tool for preparing unsaturated GAG disaccharides and the potential exo-lytic mechanism, which will benefit the initial enzyme identification and further property improvements.

Keywords:  GAG lyase; action mode; active site residue; molecular docking; sulfation

DOI:  https://doi.org/10.3389/fmicb.2025.1680841
J Biomed Mater Res A. 2025 Dec;113(12): e70009

Biomimetic Glycosaminoglycan Analog Hydrogels Inhibit Neurite Outgrowth While Supporting Neuronal Cell Viability.

Khyal Sumaya, Dar Segev, Haim S Mordechai, Malka Shilo, Mirit Sharabi, Sarit S Sivan.

  Intervertebral disc (IVD) degeneration is a leading contributor to chronic low back pain, imposing a substantial global burden. Native IVD tissue relies on sulfated glycosaminoglycans (sGAG) to maintain hydration and mechanical function through fixed negative charges and associated osmotic pressure. With aging, sGAG depletion leads to matrix disorganization, dehydration, and pathological nerve ingrowth-hallmarks of disc degeneration. Synthetic GAG analog hydrogels have recently gained attention as biomimetic candidates for disc repair, owing to their structural resemblance and fixed charge density similarity to native sGAGs. Beyond their biomechanical role, these GAG analogs are hypothesized to act as neuroinhibitory barriers. In this study, we evaluated the neuroinhibitory capability of GAG analogs at varying crosslinking densities (0.5%-2%), using SH-SY5Y neuroblastoma cells. Grown on GAG analogs, neurite extension was markedly suppressed, with average neurite lengths < 10 μm, compared to 79.3 ± 55.8 and 157.1 ± 103.8 μm in control cultures. Importantly, cell viability remained high (75%-92%), irrespective of the presence of exogenous chondroitin sulfate (CS). These findings suggest that, beyond mimicking the mechanical properties of native NP, GAG analogs can also recapitulate the neuroinhibitory roles of native sGAG, underscoring their promise as therapeutic biomaterials for IVD regeneration and the prevention of pain-related nerve infiltration.

Keywords:  glycosaminoglycan; hydrogel; intervertebral disc; low back pain; neurite outgrowth

DOI:  https://doi.org/10.1002/jbma.70009
Carbohydr Polym. 2026 Feb 01. pii: S0144-8617(25)01414-6. [Epub ahead of print]373 124630

Structurally defined synthetic heparin oligosaccharides reveal unique signatures for nanopore structural analysis of GAGs.

Jasna Nikolić Chenais, Christine Le Narvor, David Bonnaffé, Jérôme Hénault, Emeline Richard Millot, Bernard Priem, Manuela Pastoriza-Gallego, Cédric Przybylski, Abdelghani Oukhaled, Jérôme Mathé, Régis Daniel.

  Efforts to fully understand the structure-to-function relationships of glycosaminoglycans (GAGs) have been hampered by the complexity and polydispersity of GAGs and, more importantly, by the need for sensitive analytical techniques to discern their subtle structural motifs. Conventional analytical methods often fail to provide information on the sparse motifs of GAGs. Concurrently, nanopore-based analysis has shown great potential in GAGs structural analysis. Still, until now, it has been limited by the difficulty of relating ionic current changes to specific motifs. To address this, the present study allowed for obtaining reference signals by employing carefully designed synthetic sulfated tetra- to dodecasaccharides to allow precise sequence control and purity. Reference signals were obtained for specific motifs, paving the way for accurate motif recognition. The outcomes of the study demonstrated unequivocal recognition of specific GAG structures by monitoring the evolution of nanopore signals in response to the translocation of synthetic heparin (HP)-like oligosaccharides with controlled structures, allowing extensive structural discrimination. The findings highlight the nanopore's capability to detect subtle structural features, such as differences in sulfation patterns and epimerization of uronic acid. These results open the way to establishing detailed heparin (HP)-specific reference signals and to nanopore fingerprinting and sequencing of GAGs.

Keywords:  Aerolysin (AeL) nanopore; Glycan structural analysis; Glycosaminoglycans (GAGs); Heparin/ heparan sulfate microheterogeneity; Nanopore-based analysis

DOI:  https://doi.org/10.1016/j.carbpol.2025.124630
Acta Neuropathol Commun. 2025 Dec 03. 13(1): 249

Spontaneous generation of diverse recombinant prion strains: sulfated glycan cofactors facilitate strain emergence but do not determine specific strain properties.

Nuria L Lorenzo, Hasier Eraña, Enric Vidal, Jorge M Charco, Lucía Parga, Carlos M Díaz-Domínguez, Sonia Veiga, Susana Bravo, Samanta Giler, Mariví Geijo, Jesús R Requena, Joaquín Castilla.

  Significant advances over the last two decades in the study of in vitro prion formation and propagation have revealed that distinct cofactors can facilitate or induce spontaneous prion misfolding. This, in turn, has raised important questions about the role of cofactors and their potential significance in vivo in prion diseases. Key questions include whether cofactors are necessary for prion infectivity or whether they might play a crucial role in determining strain features without being essential for infection. Grounded in previous work that showed that polyanions such as RNA or dextran sulfate facilitate spontaneous prion misfolding in vitro, we have addressed whether other chemically similar cofactors could expand the diversity of PrPSc conformers and whether these would exhibit distinctive strain features. Using the Protein Misfolding Shaking Amplification (PMSA) and three different polyanionic cofactors (heparin, chondroitin sulfate and pentosan polysulfate), we obtained and characterized a total of nine conformers and compared them to previously generated strains obtained with dextran sulfate. All nine conformers proved infectious in transgenic mice, generating distinct prion strains and suggesting that different cofactors can indeed drive the formation of distinct conformers. However, the observed variations within conformers generated with the same cofactor indicate a degree of structural flexibility, likely resulting in related but distinguishable groups of conformers. Our study demonstrates that sulfated glycans not only facilitate in vitro spontaneous PrPSc generation but also enable the emergence of multiple distinct prion strains, providing insights into the molecular mechanisms underlying strain diversity and their potential relevance to spontaneous prion diseases.

Keywords:  Cofactors; PMSA; PrPSc ; Prion diseases; Prion strains; Recombinant prions; Spontaneous misfolding; Spontaneous prions; Strain diversity; Sulfated glycans

DOI:  https://doi.org/10.1186/s40478-025-02175-w
Biochem Biophys Rep. 2025 Dec;44 102363

Effect of a chondroitin sulfate chain linked to the bikunin core peptide on gene expression in lipopolysaccharide-treated uterine cervical fibroblasts.

Saki Kurotaki, Ikuko Kakizaki, Kanji Tanaka, Ryuto Tsushima, Shinichiro Suto, Seigo Tanaka, Tomoe Kodama, Asami Ito, Ryoki Takahashi, Yoshihito Yokoyama.

  Bikunin is a proteoglycan with a core protein and a low sulfated chondroitin 4-sulfate (Ch4S) chain. This chain has low 4-sulfated glucuronic acid-N-acetylgalactosamine (GlcUAβ1-3GalNAcβ1-4) repeating disaccharide units, and is covalently linked to the core protein through a glucuronic acid-galactose-galactose-xylose-serine the linkage tetrasaccharide (GlcUAβ1-3Galβ1-3Galβ1-4Xylβ1-O-Ser10). The linkage tetrasaccharide is sometimes complexly modified by phosphorylation on Xyl, sulfation on Gal, fucosylation on Xyl, or sialylation on Gal, or combinations of them. Bikunin is used in obstetrics to prevent preterm birth caused by bacterial infection inflammation in Japan. However, the role of the Ch4S chain in the anti-inflammatory action of bikunin has not been fully clarified. To investigate this role, the Ch4S chain was enzymatically removed resulting in a remaining hexasaccharide linkage (GlcUAβ1-3GalNAcβ1-4GlcUAβ1-3Galβ1-3Galβ1-4Xylβ1-O-Ser10) attached to the core peptide. The effects of exogenous bikunin or Ch4S-deficient bikunin on gene expression in lipopolysaccharide (LPS)-treated uterine cervical fibroblasts were comprehensively analyzed by DNA microarray. The expression of IL-8, an inflammation marker in this inflammatory model culture, was upregulated by LPS and the upregulation was inhibited by addition of bikunin together with LPS. Increased expression of genes, related to inflammation or collagen, by LPS was also suppressed by bikunin at the same time point. Ch4S-deficient bikunin did not show significant suppression compared to original bikunin, suggesting that the Ch4S structure of bikunin is important for the suppression of the inflammatory response induced by LPS.

Keywords:  Bikunin; Chondroitin sulfate; Lipopolysaccharide; Uterine cervical fibroblasts

DOI:  https://doi.org/10.1016/j.bbrep.2025.102363
Int J Biol Macromol. 2025 Dec 01. pii: S0141-8130(25)09856-3. [Epub ahead of print] 149299

Bioinspired hydroxyapatite nanoparticle: Functionalization with chondroitin sulfate-thiol/amine moieties for synergistic bone tissue regeneration and oxidative stress mitigation.

Priyanka Panigrahi, Nimbal Kalita, Lokanath Mishra, Monalisa Mishra, Mukesh Gupta, Harekrushna Sahoo.

  Bone fractures remains a formidable clinical challenge, particularly in oxidative and inflammatory microenvironments where conventional hydroxyapatite (HAP)-based scaffolds exhibit poor redox buffering, limited biointeractivity, and suboptimal integration with native extracellular matrix (ECM) signaling pathways. In order to address these multifactorial limitations, we report the rational design and one-pot synthesis of bioinspired nanocomposites comprising chondroitin sulfate (CS)-functionalized HAP, which is further engineered with surface-exposed thiol (-SH) or amine (-NH₂) group. This aqueous-phase synthesis simultaneously orchestrates Ca2-templated HAP nucleation and CS conjugation, enabling hierarchical assembly with molecular level interface control. Comprehensive spectroscopic and microscopic analyses validate the formation of structurally coherent, chemically stable CS-HAP nanocomposites with post-synthetic -SH and -NH₂ functionalization. The developed nanobiocomposites exhibit enhanced cytocompatibility in the MG-63 osteoblast-like cell line and effectively attenuate ROS induced apoptosis in the Drosophila melanogaster model. This one-pot synthesis strategy presents a unified platform for engineering biomimetic and osteoinductive nanoscaffolds with dual functionality, supporting bone regeneration while concurrently serving as potent antioxidant candidates. The approach holds significant translational potential for therapeutic application in oxidative stress associated bone fracture microenvironments.

Keywords:  Bone healing; Chondroitin sulfate; Hydroxyapatite nanoparticles; ROS scavengers

DOI:  https://doi.org/10.1016/j.ijbiomac.2025.149299
Carbohydr Polym. 2026 Feb 01. pii: S0144-8617(25)01443-2. [Epub ahead of print]373 124659

Structural characterization of starch-like α-glucan from the seeds of Euryale ferox Salisb and evaluation on the anti-inflammatory activity after sulfated modification.

Xiaojun Li, Haiyang Guo, Suqin Liu, Xia Luan, Yang Yang, Xue Zhang.

  Euryale ferox Salisb is a homology of medicine and food in China for more than 2000 years. However, detailed studies on the polysaccharide from seeds of E. ferox Salisb (EFSP) and sulfated EFSP for anti-inflammatory activities have not been done. In our study, a comprehensive characterization and sulfated modification of EFSP was conducted. As a result, EFSP was a low Mw polysaccharide (3.68 KDa). Monosaccharide composition and methylation analysis revealed that EFSP was composed of glucose. NMR revealed that chemical structure of EFSP was 1,4-α-D-glucan with branchpoints introduced by 1,4,6-α-glucan and 1,3,4-α-glucan. The EFSP was chemically modified by CSA-Pyr method to incorporate the sulfate groups. The DS of the S-EFSPs was determined by elemental analysis to be 0.3, 0.59 and 1.07, respectively. High DS of EFSP contributed to a fragmented morphology and high Mw. The sulfate positions were at O-6 and/or O-2/O-3 of S-EFSP. Native EFSP and sulfated EFSP could inhibited IL-6, IL-1β, and TNF-α expression in RAW 264.7 cells and promoted the polarization of macrophages to M2 type. Further investigations found that EFSP obviously affected the extracellular trap formation pathway; however, sulfated EFSP (DS 1.07) significantly affected the negative regulation of protein binding. These results indicated that EFSP and its sulfated modification are potential suppressor of inflammatory cytokines and other mediators.

Keywords:  Anti-inflammatory activities; Euryale ferox Salisb polysaccharide; Sulfated modification; α-glucan

DOI:  https://doi.org/10.1016/j.carbpol.2025.124659
Biomed Pharmacother. 2025 Dec 02. pii: S0753-3322(25)01059-5. [Epub ahead of print]193 118865

Indoxyl sulfate promoted glutamine metabolism and cell proliferation in urothelial carcinoma involving Runx2.

Jian-Ri Li, Tung-Min Yu, Yen-Chuan Ou, Chih-Cheng Wu, Shih-Yi Lin, Ya-Yu Wang, Jiaan-Der Wang, Su-Lan Liao, Wen-Ying Chen, Yu-Hsiang Kuan, Chun-Jung Chen.

  Patients with Chronic Kidney Disease (CKD) have an increased risk and poor prognosis of becoming diagnosed with urothelial carcinoma. Currently, the linking mechanisms underlying the connection between CKD and urothelial carcinoma are not well understood. CKD with declined renal function is associated with the accumulation of circulating indoxyl sulfate, a metabolite synthesized from tryptophan by gut microbes. We investigated the roles of CKD-related uremic toxins in regards to their linking with urothelial carcinoma by delivering indoxyl sulfate to urothelial carcinoma cells and tumor-bearing mice. Upon exposure to indoxyl sulfate, urothelial carcinoma T24 and NTUB1 cells increased proliferation, accompanied by enhanced glutamine uptake and metabolism. Mechanistically, Runt-Related Transcription Factor 2 (Runx2) had been identified as a contributor of both urothelial carcinoma cell proliferation and Solute Carrier Family 1 Member 5 (SLC1A5)-mediated glutamine uptake, while metabolism was demonstrated as being a target to the actions of Runx2 promoted by indoxyl sulfate. An elevated expression of Runx2 caused by indoxyl sulfate correlated with both a reduction of microRNA-204 and an induction of DNA Methyltransferase 1 (DNMT1). MicroRNA-204 agomiR decreased Runx2 expression, while DNMT1 inhibitors reversed indoxyl sulfate-induced reduction of miR-204 and induction of Runx2. Additionally, inhibition of the Aryl Hydrocarbon Receptor (AhR) alleviated indoxyl sulfate-induced signaling changes and cell proliferation. The cancer-promoting effects of indoxyl sulfate were further demonstrated in tumor-bearing mice. In short, our results suggest that indoxyl sulfate may act as a bridge in linking the gap between CKD and urothelial carcinoma by involving the enhancement of glutamine uptake and metabolism.

Keywords:  Chronic kidney disease; Glutamine; Runx2; Uremic toxin; Urothelial carcinoma

DOI:  https://doi.org/10.1016/j.biopha.2025.118865
Mater Today Bio. 2025 Dec;35 102531

Spermidine-encapsulated chondroitin sulfate methacryloyl hydrogel delivery system for remodeling bone homeostasis in rheumatoid arthritis.

Xiaocheng Wang, Jiaxin He, Yixiang Hong, Ligang Jie, Bing Wu, Jinquan Shen, Gengmin Zhou, Qingwen Wang.

  Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by persistent synovial inflammation, progressive cartilage degradation, and osteoclast-mediated bone erosion. While current systemic therapies alleviate inflammation, they often fail to prevent structural joint damage or promote local tissue regeneration. Herein, we developed a chondroitin sulfate methacryloyl (ChSMA) hydrogel-based delivery system encapsulating spermidine (SPD), a naturally occurring polyamine with emerging anti-inflammatory, senescence-attenuating, and chondroprotective properties, to achieve localized and sustained treatment of RA-related joint destruction. Using an RA-mimicking co-culture model comprising RA patient-derived synovial organoids and chondrocytes, we demonstrated that ChSMA@SPD effectively attenuated chondrocyte apoptosis and suppressed the expression of pro-inflammatory cytokines and matrix metalloproteinases (MMPs). In addition, ChSMA@SPD significantly inhibited osteoclast differentiation in vitro using primary bone marrow-derived monocytes from mice by downregulating dendritic cell-specific transmembrane protein (DC-STAMP) expression. In vivo studies using the collagen-induced arthritis (CIA) mouse model further confirmed that intra-articular administration of ChSMA@SPD reduced arthritis severity, preserved cartilage integrity, and mitigated joint inflammation. Furthermore, network pharmacology and molecular docking analyses identified key signaling pathways and potential molecular targets of SPD, such as TGFB2, XIAP, MMP8, and PLA2G1B. Collectively, our findings highlight ChSMA@SPD as a dual-functional hydrogel platform that simultaneously protects cartilage and suppresses bone resorption, offering a promising localized therapeutic strategy for RA treatment.

Keywords:  Cartilage protection; Chondroitin sulfate hydrogel; Osteoclastogenesis; Rheumatoid arthritis; Spermidine

DOI:  https://doi.org/10.1016/j.mtbio.2025.102531
Carbohydr Polym. 2026 Feb 01. pii: S0144-8617(25)01405-5. [Epub ahead of print]373 124621

Seaweed polysaccharides and their potential health effects via gut microbiota modulation.

Mustafa Fevzi Karagöz, Buket Özen Ünaldı, Ceren Albayrak Buhurcu, Nilüfer Şen, Gökçe Sueda Aydoğdu, Kezban Şahin Demirci, Zeynep Gül Gündüz, Meryem Saban Güler, Duygu Ağagündüz, Filipe Coreta-Gomes.

  Macroalgae, commonly known as seaweeds, are a valuable source of polysaccharides known to modulate gut microbiota. In this work, the impact of polysaccharide structural features on gut microbiota was explored. The low molecular weight algae polysaccharides showed better degradation by gut bacteria. Moreover, the content of sulfate and carboxylic groups seem to promote high fermentation, triggering an increase in gut microbiota health. The effect of ramification degree of algae polysaccharides on fermentability is still unclear. Agar polysaccharides with low molecular weight and a higher degree of sulfation have been shown to produce higher amounts of SCFA, and decrease in Firmicutes/Bacteroidetes ratio. An increase of sulfation degree of porphyran showed to increase the total SCFA production and a decrease on the ratio of butyric to propionic acid. Carrageenan's molecular weight does not seem to affect SCFA production, and the effect of sulfation degree is not clear. The consumption of these polysaccharides was shown to decrease the Firmicutes/Bacteroidetes ratio. Fucoidans of low molecular weight seem to promote a lower Firmicutes/Bacteroidetes ratio. Alginate consumption both of high and low molecular weight has been shown to increase Bacteroidetes. Low molecular weight laminarans are highly fermented and significantly increase the production of SCFA. Ulvan and sulfated rhamnan polysaccharides have been shown to increase the production of SCFA, although microbiota modulation data are still undisclosed. Overall, seaweed polysaccharides have shown several health benefits, which have been related with gut microbiota modulation.

Keywords:  Gut microbiota; Health; Macroalgae; Microbiome; Modulation; Seaweed polysaccharides

DOI:  https://doi.org/10.1016/j.carbpol.2025.124621
Carbohydr Polym. 2026 Feb 01. pii: S0144-8617(25)01339-6. [Epub ahead of print]373 124555

Influence of cationic species on β-agarase-mediated depolymerization of agarans.

Sanjida Humayun, Md Musa Howlader, Malle Roosild, Amal D Premarathna, Vitalijs Rjabovs, Rando Tuvikene.

  This study explores the enzymatic degradation of red algal galactans-agarose, porphyran, and funoran-using 19 commercial hydrolases, including β-galactosidases, β-galactanases, β-agarases, and β-porphyranases. While agarose and porphyran hydrolysis is well studied, funoran degradation, particularly under ionic conditions, remains poorly understood. We evaluated the impact of mono- (Na+, K+, NH₄+) and divalent (Mg2+, Ca2+, Ba2+) cations on β-agarase 86A (GH86). Divalent ions, especially Ba2+, significantly enhanced funoran hydrolysis, with optimal activity at 20 mM BaCl₂. This enhancement is attributed to Ba2+ shielding -OSO₃- groups in funoran, facilitating structural rearrangements that improve enzyme access. Notably, β-agarase 86A exhibited broad substrate specificity, cleaving β-(1→4) linkages in all three galactans. NMR analysis confirmed cleavage between G6S and LA residues in funoran, releasing LA-G6S disaccharides via an endo-acting mechanism. This is the first report demonstrating Ba2+-mediated enhancement of funoran degradation. These results provide mechanistic insights into ion-assisted enzymatic depolymerization of sulfated agarans. The findings broaden the substrate range of GH86A enzymes and highlight Ba2+ as a key modulator for improving enzymatic accessibility to complex sulfated galactans, with potential applications in biocatalysis and bioactive oligosaccharide production.

Keywords:  Agaran; Agarase; Barium ions; Enzymatic depolymerization; GH86 enzyme; NMR; Shielding effect; Sulfate group

DOI:  https://doi.org/10.1016/j.carbpol.2025.124555
World J Surg Oncol. 2025 Dec 02.

Chondroitin sulfate proteoglycan 4 (CSPG4) overexpression as an oncogenic driver and prognostic marker for unfavorable outcomes in hepatocellular carcinoma.

Changjie Ren, Feihu Yan, Hao Xiang, Tianyu Hong, Abudurexiti Mierxiati, Ling Zhang, Mingda Wang, Chao Wang.

   BACKGROUND: A significant challenge in improving outcomes for hepatocellular carcinoma (HCC) patients is the scarcity of reliable prognostic markers and predictive tools. Chondroitin Sulfate Proteoglycan 4 (CSPG4) has shown potential as an oncogenic driver in various cancers, but its role in HCC is largely unexplored.
METHODS: CSPG4 expression was analyzed using The Cancer Genome Atlas data and two independent cohorts of HCC patients who underwent curative-intent hepatectomy (n = 153 and n = 112). Immunohistochemistry was used to assess CSPG4 expression. The optimal cutoff value for CSPG4 H-score was determined by receiver operating characteristic (ROC) curve analysis combined with the Youden index. Survival curves were plotted via the Kaplan-Meier method, and differences in survival rates were compared using the log-rank test. Multivariate analyses were utilized to determine the prognostic significance of CSPG4, both independently and in conjunction with established clinical parameters. In vitro studies using CSPG4 knockdown or recombinant CSPG4 protein treatment in HCC cell lines were conducted, with cell proliferation, migration and invasion assessed by CCK-8, wound healing and transwell assays.
RESULTS: The expression of CSPG4 was significantly upregulated in HCC tissues compared to adjacent normal liver tissues. Elevated levels of CSPG4 were associated with more severe clinical and pathological characteristics, as well as reduced overall survival (OS) and shorter progression-free survival (PFS) across both study groups. In vitro experiments demonstrated that CSPG4 knockdown suppressed proliferation, migration and invasion of HCC cells, while recombinant CSPG4 protein treatment promoted cell proliferation in a dose-dependent manner. High CSPG4 expression was an independent risk factor for OS in HCC patients after resection (hazard ratio 2.577, 95% confidence interval [CI]: 1.564-4.246, P < 0.001). The combined predictive model incorporating CSPG4 expression with clinical parameters, especially tumor size and microvascular invasion achieved a C-index of 0.811 (95% CI: 0.742-0.881) for OS prediction, which was significantly superior to traditional staging systems.
CONCLUSION: CSPG4 overexpression serves as an oncogenic driver and independent predictor of poor survival in HCC. Combining CSPG4 expression with established clinical variables presents a more precise risk assessment tool for individuals with HCC after hepatectomy, offering new insights for personalized treatment strategies and outcome prediction in HCC.

Keywords:  Chondroitin sulfate proteoglycan 4; Hepatocellular carcinoma; Oncogene; Prediction; Prognosis

DOI:  https://doi.org/10.1186/s12957-025-04133-1
Stem Cell Res Ther. 2025 Dec 02.

Culturing hypoxia-primed mesenchymal stem cells in xeno- and serum-free conditions facilitates the synthesis of an extracellular matrix-based biologic with augmented therapeutic potential for the treatment of diabetic wounds.

Kwok Keung Lit, Cheuk Kwan Owen Li, Zhamilya Zhirenova, Anna Blocki.

  Diabetic wound healing is severely impaired by poor angiogenesis, neuropathy, chronic inflammation, decreased cell proliferation and dysregulated extracellular matrix (ECM) synthesis. Here, we developed a human mesenchymal stem cell (MSC)-derived ECM-based biologic with augmented pro-angiogenic potential, free of any xeno- and serum-free components, aimed at treating diabetic wounds. Hypoxia-primed MSCs, cultured in chemically defined medium, synthesized a secretome enriched in pro-angiogenic factors. This secretome was aggregated and co-precipitated by a heparan sulfate mimetic, dextran sulfate (DxS), into the pericellular space. MSCs assembled the deposited secretome components into an insoluble ECM, which upon decellularization was processed into MIcroParticles of SOlidified Secretome (MIPSOS), an ECM-DxS composite biologic. This formulation of MIPSOS demonstrated augmented pro-angiogenic bioactivity in vitro and in vivo and accelerated revascularization, re-epithelization and wound closure by almost doubling wound closure rate, and outperforming GraftJacket®, a clinically utilized decellularized human dermis-derived biologic. MIPSOS-treated wounds showed enhanced cellular infiltration and granulation tissue formation, along with a reduced presence of macrophages, indicating progression toward inflammation resolution. MIPSOS thus provides a novel treatment alternative that overcomes major limitations of soluble factor-based, tissue-derived ECM-based, as well as cell-based therapies, offering significant improvements in diabetic wound management.

Keywords:  Diabetic wound healing; Extracellular matrix; Hypoxic culture; Revascularization; Xeno-free/serum-free

DOI:  https://doi.org/10.1186/s13287-025-04827-z
Nat Commun. 2025 Nov 29. 16(1): 10816

Plasma membrane transbilayer asymmetry of PI(4,5)P2 drives unconventional secretion of Fibroblast Growth Factor 2.

Manpreet Kaur, Fabio Lolicato, Walter Nickel.

Unconventional secretion of Fibroblast Growth Factor 2 (FGF2) is mediated by direct translocation across the plasma membrane. This process is initiated by PI(4,5)P2-dependent FGF2 oligomerization at the inner plasma membrane leaflet. PI(4,5)P2 is a non-bilayer lipid that accumulates at sites of FGF2 oligomerization, imposing severe membrane stress that is relieved by the formation of a lipidic membrane pore. At the outer leaflet, FGF2 oligomers are captured and disassembled by the heparan sulfate proteoglycan Glypican-1 (GPC1), making available FGF2 to engage in ternary signaling complexes on cell surfaces. Using an in vitro reconstitutions system, this study provides direct evidence that transbilayer asymmetry of PI(4,5)P2 promotes rapid kinetics of membrane pore formation. Likewise, FGF2 secretion from cells is inhibited when PI(4,5)P2 plasma membrane transbilayer asymmetry is disrupted. We propose the asymmetric distribution of PI(4,5)P2 to lower the energetic barrier for membrane pore formation, enabling rapid kinetics of FGF2 membrane translocation into the extracellular space.

DOI: https://doi.org/10.1038/s41467-025-66860-z
Bioanalysis. 2025 Dec 01. 1-10

Quantification of keratan sulfate in biofluids by validated HPCE-LIF: application to Morquio syndrome.

Fabio Galeotti, Lucia Zampini, Francesca Maccari, Chiara Monachesi, Lucia Padella, Lucia Santoro, Orazio Gabrielli, Nicola Volpi.

   BACKGROUND: Keratan sulfate (KS) is altered in several pathological conditions. We report the capillary electrophoresis-laser induced fluorescence separation and validation of KS-derived disaccharides Galβ(1-4)GlcNAc(6S) and Gal(6S)β(1-4)GlcNAc(6S) in human urine and plasma after keratanase II treatment and AMAC fluorotagging.
RESULTS: The calibration curves of the two disaccharides from 50 to 1000 ng showed an average correlation coefficient greater than 0.9970 and the calculated LOD and LOQ were 3 and 10 ng, respectively. The inter-day precision was ~13% and the inter-day accuracy was ~10% for both disaccharides. The % recovery ranged between 88% and 106% for 200, 500, and 800 ng of each disaccharide added to biofluids. Urine and plasma of Morquio A and B subjects and of patients submitted to ERT treatment were tested. Urinary KS was ~13-16-fold more abundant in MPSIVA and plasmatic KS was significantly ~2-3-fold more than controls. No differences were observed for the disaccharides ratio between Patients and not-affected Subjects.
CONCLUSION: The capillary electrophoresis separation of the two main KS disaccharides in human biofluids was found specific, sensitive, and accurate and suitable for application to Morquio syndrome early detection and progression as well as for other conditions in which KS is altered in content and structure.

Keywords:  AMAC; Keratan sulfate; Morquio syndrome; capillary electrophoresis; mucopolysaccharidosis

DOI:  https://doi.org/10.1080/17576180.2025.2597552