bims-supasi 2026-04-05 papers

bims-supasi

Biomed News

on Sulfation pathways and signalling

Issue of 2026–04–05
sixteen papers selected by
Jonathan Wolf Mueller, University of Birmingham

Development of a Specific and Sensitive LC-MS/MS Method to Quantify Heparan Sulfate 3-O-Sulfotransferase-1 Activity.
Sulfatase modifying factors control the timing of zebrafish convergence and extension morphogenesis.
Heparan sulfate is essential for Drosophila FGF export.
Enzymatic depolymerization, structural characterization, and anticoagulant activity evaluation of chondroitin sulfate A oligosaccharides.
Strain level variation in Proteus mirabilis chondroitin sulfate degradation kinetics and regulation by urea.
The Diverse Roles of Heparan Sulfate in RNA Virus Infections: Insights From Enterovirus A71, Severe Acute Respiratory Syndrome Coronavirus 2, and Chikungunya Virus.
Neuronal Axon Generation/Regeneration Regulated by Sulfated Glycans.
Impact of Intravesical Chondroitin Sulfate Instillation on Sexual Function in Women with Interstitial Cystitis/Bladder Pain Syndrome.
Purification, structural characterization, and anticoagulant activity of chondroitin sulfate/dermatan sulfate from cobra (Naja naja atra).
Arylsulfatase I is a novel lysosomal chondroitin endosulfatase regulating endochondral ossification.
Sulfated Glycosaminoglycans in Inflammation.
Optimization of Chondroitin Sulfate Extraction From Skate (Raja spp.) Cartilage Using Response Surface Methodology: Anti-Inflammatory and Chondroprotective Activities.
Melanoma/CSPG4-Enhanced Collagen-Mediated Contact Guidance Requires Mutant Active BRAF and the CSPG4 Core Protein Cytoplasmic Domain.
Development of Anti-Inflammatory Extracellular Vesicles by Surface Expression of Syndecan-4.
Uremic toxin p‑cresyl sulfate enhances the calcification of aortic valvular interstitial cells via klotho/sirtuin‑1 signaling.
Molecular pharmacology of sulfated polysaccharides from Sargassum fusiforme: mechanistic insights into HIV inhibition and immune modulation- a review.

Glycobiology. 2026 Mar 31. pii: cwag024. [Epub ahead of print]

Development of a Specific and Sensitive LC-MS/MS Method to Quantify Heparan Sulfate 3-O-Sulfotransferase-1 Activity.

Vivien Uyen Doan, Yongmei Xu, Zhangjie Wang, Andrea M Kaminski, Lars C Pedersen, Jian Liu.

  Heparan sulfate (HS) is a highly sulfated glycan that regulates diverse biological processes through specific sulfation patterns. Among these, 3-O-sulfation catalyzed by heparan sulfate 3-O-sulfotransferase-1 (3OST-1) is rare but functionally critical, influencing anticoagulation and contributing to the progression of Alzheimer's disease and cancer progression. However, direct measurement of 3OST-1 activity in biological systems has been limited by the lack of sensitive and specific assays. Here we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay using a structurally defined HS hexasaccharide substrate and 13C-labeled internal standards. This method enables nanogram-level detection of 3-O-sulfated products following heparinase digestion and AMAC derivatization. The LC-MS/MS assay demonstrated 100-fold improved sensitivity compared to HPLC and successfully quantified endogenous 3OST-1 activity in HCT-116 cells and conditioned media. Using this assay, we confirmed that the 3OST-1 E86Q mutant acts as a dominant-negative inhibitor. E86Q mutant retains substrate and donor binding but abolishes catalytic activity, reducing wild-type 3OST-1-like activity by >80% in vitro and significantly decreasing 3-O-sulfated HS products in cells without affecting overall HS abundance. This assay provides the first quantitative tool for 3OST-1-like activity and establishes a dominant-negative strategy for functional studies, offering new opportunities for biomarker development and therapeutic targeting in HS-related pathologies.

Keywords:  3-O-sulfation; LC-MS; enzyme activity assay; heparan sulfate ; sulfotransferase

DOI:  https://doi.org/10.1093/glycob/cwag024
Nat Commun. 2026 Mar 31.

Sulfatase modifying factors control the timing of zebrafish convergence and extension morphogenesis.

Ailen Soledad Cervino, Amrita Basu, Ryan J Weiss, Gursimran Kaur Bajwa, Rubén Marín-Juez, Sandra L Grimm, Cristian Coarfa, Margot Kossmann Williams.

Convergence and extension (C&E) cell movements that elongate the primary embryonic axis are precisely timed during vertebrate gastrulation, but mechanisms controlling their onset remain unknown. Using zebrafish embryonic explants that recapitulate C&E and its timing, we identified sulfatase modifying factor 2 (sumf2) as a candidate trigger gene for C&E onset. sumf2 and its paralog sumf1 encode negative and positive sulfatase regulators, respectively, whose expression levels invert and increase heparan sulfate sulfation during gastrulation. Overexpressing sumf1 or sumf2 causes delayed or precocious C&E, respectively, whereas their loss shifts C&E timing in the opposite direction. We identified Sulf1, a modifier of heparan sulfate proteoglycans (HSPGs), as their key downstream effector and found that altering heparan sulfate sulfation levels shifts C&E onset and suppresses sumf1 and sumf2 mutant phenotypes. This work supports a model in which sumf2 expression reduces sulfatase activity, rewriting HSPG sulfation patterns to promote the onset of C&E morphogenesis.

DOI: https://doi.org/10.1038/s41467-026-70804-6
bioRxiv. 2026 Mar 26. pii: 2026.03.24.714045. [Epub ahead of print]

Heparan sulfate is essential for Drosophila FGF export.

Guilherme Oliveira Barbosa, Christian Solis-Calero, Thomas B Kornberg.

Binding of Fibroblast growth factor (FGF) to a heparan sulfate proteoglycan (HSPG) is required for paracrine FGF signaling. To improve our understanding of FGF:HSPG association, we developed a method to monitor export of the Drosophila FGF ortholog Branchless (Bnl) in vivo . We detected Bnl on the surface of approximately 10% of Bnl-producing cells, but Bnl on the surface of cells depleted of HS was much reduced. HS depletion also non-autonomously decreased the activity of cytonemes that extend from cells that receive Bnl. These results are consistent with the idea that Bnl export to the cell surface is regulated, that intracellular binding of an HSPG to Bnl in producing cells is essential for export, and that cells that take up Bnl actively participate in its release from producing cells.
Summary: Levels of FGF exported to the surface of FGF-expressing cells are dependent on intracellular heparan sulfate proteoglycans.

DOI: https://doi.org/10.64898/2026.03.24.714045
Carbohydr Res. 2026 Mar 27. pii: S0008-6215(26)00093-5. [Epub ahead of print]564 109904

Enzymatic depolymerization, structural characterization, and anticoagulant activity evaluation of chondroitin sulfate A oligosaccharides.

Kaiqiang Li, Yuanjie Liu, Chen Zhang, Huahua Yu, Song Liu, Ronge Xing, Pengcheng Li, Rongfeng Li.

  Chondroitin sulfate (CS) polysaccharides exhibit intrinsic structural heterogeneity, limiting precise studies of their bioactivities and therapeutic applications. To obtain homogeneous CS oligosaccharides and elucidate structure-activity relationships, we developed a controlled enzymatic method for preparing well-defined chondroitin sulfate A (CSA) oligosaccharides and investigated their chain length-dependent anticoagulant mechanisms. Herein, hyaluronidase was used to depolymerize CSA and subsequently purified by sequential ultrafiltration and anion-exchange chromatography, yielding CSA oligosaccharide fractions (CSA4, CSA6, CSA8, CSA10 and CSA12). Their structures were confirmed by NMR spectroscopy and mass spectrometry. In vitro anticoagulation assays showed significant chain-length dependence: longer oligomers (CSA8, CSA10 and CSA12) profoundly prolonged activated partial thromboplastin time (APTT) and thrombin time (TT), suggesting potentiation of endogenous serine protease inhibitors. However, shorter oligomers (CSA4 and CSA6) just selectively prolonged prothrombin time (PT), indicating extrinsic pathway modulation. This work provides a reliable method for preparing CSA oligosaccharides and establishes a molecular foundation for developing safer, predictable CS-based anticoagulants.

Keywords:  Anticoagulant activity; Chondroitin sulfate A; Oligosaccharides; Structure-activity relationship

DOI:  https://doi.org/10.1016/j.carres.2026.109904
bioRxiv. 2026 Mar 24. pii: 2026.03.23.713754. [Epub ahead of print]

Strain level variation in Proteus mirabilis chondroitin sulfate degradation kinetics and regulation by urea.

Brianna M Shipman, Serena Zhou, Benjamin Hunt, Vitus Brix, Ibrahim Salaudeen, Anna N Evers, Brian S Learman, Nicholas A Dillon, Philippe E Zimmern, Chelsie E Armbruster, Nicole J De Nisco.

To establish infection, uropathogens must overcome several host defenses including the glycosaminoglycan (GAG) layer coating the apical surface of the bladder urothelium. GAGs are thought to protect against urinary tract infection (UTI) by serving as scaffolding sites for commensals, providing barrier function and preventing uropathogen adherence. However, the ability of uropathogens to degrade and utilize GAGs and the contribution of these activities toward UTI progression is largely unknown. We previously discovered that the uropathogen Proteus mirabilis, a common cause of catheter-associated UTI (CAUTI), degrades the GAG chondroitin sulfate (CS). In this study we sought to define the kinetics and regulation of CS degradation by diverse P. mirabilis strains clinically isolated from both recurrent UTI and CAUTI patients. We found variation in CS degradation kinetics between P. mirabilis strains and media types. However, CS degradation depended on conserved putative chondroitin sulfate ABC endo- and exolyases in all strains. Furthermore, we found that CS degradation in Pm123 was repressed by urea and that this repression was dependent on P. mirabilis urease activity. Complementation of the Pm123 endolyase into urea-insensitive HI4320 resulted in a urea-sensitive CS degradation phenotype suggesting functional differences between the Pm123 and HI4320 endolyases. Sequence alignment and structural modeling analysis identified two unique point mutations within the Pm123 endolyase that may contribute to urea sensitivity. Finally, unlike urea-insensitive P. mirabilis strains, Pm123 demonstrated attenuated swarming and loss of chondroitin endolyase activity had no effect on Pm123 virulence in a mouse CAUTI model. Our results suggest that the kinetics and regulation of CS degradation differ between P. mirabilis strains and in urea-sensitive strains, thus reduces the contribution of CS degradation to urovirulence during murine CAUTI.
Importance: This work demonstrates that the ability to degrade a common component of bladder mucosal surfaces, chondroitin sulfate, is a phenotype that is shared by multiple strains of the common catheter-associated UTI (CAUTI) pathogen P. mirabilis . We find that this activity is dependent on encoded chondroitin ABC endo- and exolyases, first described in Proteus vulgaris . Additionally, we discovered that for P. mirabilis strain Pm123, degradation of CS is negatively regulated by the presence of urea, a major component of urine. The repression of CS degradation by urea is dependent on the activity of the P. mirabilis urease enzyme, which breaks down urea producing ammonia which raises pH. We found expression of the Pm123 CS endolyase was sufficient to confer a urea-sensitive CS-degradation phenotype and identified two unique mutations within the Pm123 enzyme that may contribute to urea sensitivity. Finally, we find that while CS-degradation plays a role in progression and severity of murine CAUTI model in urea-insensitive P. mirabilis, there was not significant difference in CAUTI outcomes between the urea-sensitive Pm123 wild-type and chondroitinase knockout strains. This study represents a major step forward in understanding the diversity of CS degradation activity and regulation among clinical strains of the critically important CAUTI pathogen P. mirabilis as well as its contribution to urovirulence.

DOI: https://doi.org/10.64898/2026.03.23.713754
J Med Virol. 2026 Apr;98(4): e70888

The Diverse Roles of Heparan Sulfate in RNA Virus Infections: Insights From Enterovirus A71, Severe Acute Respiratory Syndrome Coronavirus 2, and Chikungunya Virus.

Chun Hao Theo, I-Ching Sam, Yoke Fun Chan.

  Heparan sulfate (HS), a ubiquitously expressed glycosaminoglycan, functions as an attachment and/or internalization factor for diverse RNA and DNA viruses. Its broad viral attachment capacity arises from structural heterogeneity in sulfation patterns. This review examines HS interactions in enterovirus A71 (EV-A71), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and chikungunya virus (CHIKV), emphasizing shared features and virus-specific distinctions. HS mediates viral attachment in all three, and additionally promotes SARS-CoV-2 internalization when host receptor angiotensin-converting enzyme 2 is absent. Positively charged residues on the virion dictate HS affinity. High HS affinity enhances in vitro infectivity and plaque size in EV-A71 and SARS-CoV-2, though evidence for CHIKV remains inconclusive. In vivo, elevated HS affinity is associated with viral attenuation and diminished inflammatory responses for both EV-A71 and CHIKV; in EV-A71 specifically, increased HS affinity further correlates with reduced capsid stability and heightened sensitivity to neutralizing antibodies. HS mimetics targeting viral-HS interactions represent promising broad-spectrum antivirals, particularly those advancing in clinical trials.

Keywords:  chikungunya virus; enterovirus A71; heparan sulfate; immune response; severe acute respiratory syndrome coronavirus 2; viral infections

DOI:  https://doi.org/10.1002/jmv.70888
Adv Exp Med Biol. 2026 ;1491 9-19

Neuronal Axon Generation/Regeneration Regulated by Sulfated Glycans.

Kenji Kadomatsu, Kazuma Sakamoto.

  It has long been recognized that central nerve axons do not regenerate spontaneously in adults. On the other hand, it is also known that axons of embryonic neurons and peripheral neurons, even of adults, can regenerate and reconstruct neural circuits. These differences can be attributed to intrinsic factors, that is, the regenerative capacities of neurons, and extrinsic factors, that is, the extracellular environments. Recent analyses at the single-cell level have led to a better understanding of the molecular mechanisms that underlie differences in the regenerative ability of neurons. At the same time, our understanding of the extracellular environments that determine whether neural axons can regenerate has also advanced. Sulfated glycans, which are sugar chains known as "third life chains" in addition to nucleic acids and proteins, are among the most important extracellular molecules involved in conferring regenerative capacity. Once thought to be merely a physical barrier to neuronal axons, the sulfated glycans have recently been shown to inhibit neuronal axon regeneration via their specific neuronal receptors and intracellular signaling. In this chapter, we will introduce the recent advances in our understanding of the regulation of nerve axons by sulfated glycans, while unraveling the history of research on axon regeneration.

Keywords:  Autophagy; Axon regeneration; Chondroitin sulfate; Dystrophic endball; Heparan sulfate; Receptor-type protein tyrosine phosphatase

DOI:  https://doi.org/10.1007/978-3-032-04153-1_2
Int Urogynecol J. 2026 Mar 28.

Impact of Intravesical Chondroitin Sulfate Instillation on Sexual Function in Women with Interstitial Cystitis/Bladder Pain Syndrome.

Murat Uçar, Murat Topcuoğlu, Ali Akkoç, Erkan Karadağ, Serkan Özler, Semih Keskin.

   INTRODUCTION AND HYPOTHESIS: Sexual dysfunction is highly prevalent among women with interstitial cystitis/bladder pain syndrome (IC/BPS), yet evidence regarding the effects of intravesical therapies on sexual function remains limited. Intravesical chondroitin sulfate was used as a therapeutic option to alleviate symptoms of IC/BPS by restoring the glycosaminoglycan layer of the bladder. On the basis of previous clinical evidence, we hypothesized that intravesical chondroitin sulfate instillation would be associated with improvements in female sexual function and bladder-related symptoms in women with IC/BPS.
METHODS: This single-center retrospective study analyzed prospectively collected data from sexually active women with IC/BPS who underwent intravesical chondroitin sulfate instillation between January 2023 and March 2025. Patients refractory to conservative and oral medical therapies were included. Sexual function was assessed using the Turkish validated version of the Female Sexual Function Index (FSFI). Bladder-related symptoms were evaluated using the Visual Analog Scale (VAS), Interstitial Cystitis Symptom Index (ICSI), and Interstitial Cystitis Problem Index (ICPI). Outcomes were compared between baseline and the 6-month follow-up.
RESULTS: A total of 22 women were included in the analysis. The mean total FSFI score increased significantly from 16.22 ± 6.75 at baseline to 21.53 ± 7.11 at 6 months (p < 0.001). Significant improvements were observed in desire (p = 0.002), arousal (p = 0.010), lubrication (p = 0.001), orgasm (p < 0.001), satisfaction (p = 0.006), and pain (p = 0.002) after treatment. In parallel, bladder-related symptoms improved significantly, with reductions in VAS, ICSI, and ICPI scores at the 6-month follow-up.
CONCLUSIONS: Intravesical chondroitin sulfate instillation was associated with significant improvements in sexual function and bladder-related symptoms in women with IC/BPS. These findings suggest that barrier-restoring intravesical therapy may represent a beneficial treatment option for addressing sexual dysfunction in this population.

Keywords:  Bladder pain syndrome; Chondroitin sulfate; Female sexual function index; Interstitial cystitis; Intravesical therapy; Sexual function

DOI:  https://doi.org/10.1007/s00192-026-06611-w
Carbohydr Res. 2026 Mar 30. pii: S0008-6215(26)00098-4. [Epub ahead of print]564 109909

Purification, structural characterization, and anticoagulant activity of chondroitin sulfate/dermatan sulfate from cobra (Naja naja atra).

Zhiqing Tian, Shuifang Zhu, Fan Jiang.

  Snakes are widely farmed in China, Southeast Asia, and India, with extensive applications in food and medicine; however, glycosaminoglycans (GAGs) derived from these sources remain largely understudied. In this study, GAGs were extracted and purified from the bone and carcass of the cobra (Naja naja atra) to investigate their structural characteristics and bioactivities. Structural analysis, including 1H NMR spectroscopy and disaccharide composition assays, identified the purified fractions (CBF2 and CCF2) as chondroitin sulfate/dermatan sulfate (CS/DS). These fractions exhibited structural heterogeneity, containing 35.9% and 28.8% iduronic acid, respectively, with disaccharide profiles dominated by A-type units (>80%) and high 4S/6S ratios (10.31 and 18.27, respectively). In vitro assays demonstrated that CBF2 and CCF2 possessed anticoagulant activity, prolonging activated partial thromboplastin time (aPTT) and thrombin time (TT) compared to conventional CS. These findings highlight the critical role of uronic acid epimerization in modulating the biological functions of GAGs.

Keywords:  Anticoagulant activity; Chondroitin sulfate; Dermatan sulfate; Naja naja atra

DOI:  https://doi.org/10.1016/j.carres.2026.109909
Matrix Biol. 2026 Mar 29. pii: S0945-053X(26)00026-0. [Epub ahead of print]

Arylsulfatase I is a novel lysosomal chondroitin endosulfatase regulating endochondral ossification.

Rafaela Grecco-Machado, Satomi Nadanaka, Yuko Naito-Matsui, Maria Iavazzo, Devin S Brown, Marziyeh Hassanzadeh, Tuanjie Chang, Elena Polishchuk, Ingrid J Pickering, Graham N George, Mark J Hackett, Nicola Volpi, Carmine Settembre, Hiroshi Kitagawa, B Frank Eames.

  During endochondral ossification, chondrocytes undergo maturation and biochemically modify the collagenous extracellular matrix of cartilage. Similar modifications to cartilage proteoglycans (PGs), which are predominantly chondroitin sulfate PGs, have not been characterized. Using synchrotron X-ray fluorescence imaging, we demonstrated that PG sulfation significantly decreased during cartilage maturation of chick embryos. Laser-capture microdissection and RNAseq revealed upregulation of Arylsulfatase I (Arsi) in mature cartilage of mouse. ARSI protein also increased in mature cartilage of mouse and chick in vivo and during maturation of ATDC5 chondrocytes in vitro, whereas expression of the two known chondroitin sulfate PG sulfatases (ARSB and GALNS) was not specific to mature cartilage. Colocalization studies suggested that ARSI is lysosomal, and lysosome homeostasis was altered in ARSI loss of function chondrocytes. Biochemical analyses of ARSI gain and loss of function cell lines and isolated cell-free systems revealed that ARSI is a novel chondroitin endosulfatase, specifically desulfating chondroitin-4-sulfate at pH 4.5. Finally, Arsi knockout in RCS chondrocytes caused increased expression of maturation genes, such as Col10a1 and Mmp13. In total, these data identify ARSI as a novel PG sulfatase regulating endochondral ossification.

Keywords:  ARSI; XRF imaging; cartilage maturation; chondroitin sulfate proteoglycans; endochondral ossification; endosulfatase

DOI:  https://doi.org/10.1016/j.matbio.2026.03.005
Adv Exp Med Biol. 2026 ;1491 221-231

Sulfated Glycosaminoglycans in Inflammation.

Satomi Nadanaka, Hiroshi Kitagawa.

  Inflammation has long been regarded as a tissue repair mechanism activated by the body in response to infection or tissue injury. In recent years, chronic inflammation has been implicated as a proinflammatory factor not only in various diseases, such as cancer, atherosclerosis, obesity, and Alzheimer's disease, which increase with age, but also in the aging process itself. What mechanisms cause the inflammatory response that normally dissipates, persists, and becomes chronic? Elucidating the factors that cause chronic inflammation and the mechanisms that induce it will provide insights into the prevention and control of various age-related diseases. In this review, we focus on proteoglycans as factors that cause chronic inflammation and discuss proteoglycans as DAMPs that cause inflammation.

Keywords:   DAMPs; Glycosaminoglycan; Heparan sulfate; Inflammation; Proteoglycan; Chondroitin sulfate

DOI:  https://doi.org/10.1007/978-3-032-04153-1_14
J Food Sci. 2026 Apr;91(4): e71013

Optimization of Chondroitin Sulfate Extraction From Skate (Raja spp.) Cartilage Using Response Surface Methodology: Anti-Inflammatory and Chondroprotective Activities.

Se Yeon Kim, Kwanyong Choi, Kyeong Jin Kim, Jae-Ho Hwang, Ji Yeon Kim.

  The enzymatic hydrolysis of skate cartilage utilizing Alcalase and Protamex was optimized by response surface methodology (RSM). The quadratic model was adequate, confirming its appropriateness for optimization. The optimal parameters for the extraction of total uronic acids were a 0.98% enzyme concentration, 264 min of hydrolysis, and a hydrolysate-to-ethanol ratio of 1:2.14. High-performance liquid chromatography analysis revealed ∆Di-6S as the principal disaccharide. To validate the optimized extract, biological assays were performed in lipopolysaccharide-stimulated RAW264.7 macrophages and interleukin (IL)-1β-induced SW1353 chondrocytes. Skate cartilage extract (SCE) significantly reduced nitric oxide levels (p < 0.001) and cytokine levels of IL-1β (p = 0.028), IL-6 (p = 0.004), and tumor necrosis factor-α (p < 0.001) in a dose-dependent manner in RAW264.7 macrophages, indicating the suppression of inflammatory signaling pathways. The high chondroitin-6-sulfate may contribute to these anti-inflammatory effects. In IL-1β-induced SW1353 chondrocytes, SCE dose-dependently increased the mRNA expression of aggrecan (p = 0.022) and type II collagen (p = 0.033), indicating that SCE may counteract IL-1β-induced suppression of gene expression. This study indicates that RSM is a useful approach for optimizing extraction conditions from skate cartilage. In vitro assays showed that the optimized extract attenuated inflammatory markers in macrophages and upregulated aggrecan and type II collagen mRNA in chondrocytes. Therefore, the SCE produced under RSM-optimized conditions demonstrates modulatory effects on inflammatory responses and cartilage matrix gene expression in vitro. PRACTICAL APPLICATIONS: This paper describes the RSM-based optimization of enzymatic extraction conditions to maximize CS-rich extract yield from skate (Raja spp.) cartilage, a sustainable marine by-product of fish processing. The optimized extract was rich in chondroitin sulfate, particularly chondroitin-6-sulfate, and demonstrated in vitro anti-inflammatory and chondroprotective effects.

Keywords:  anti‐inflammatory activity; chondroitin sulfate; chondroprotective activity; response surface methodology; skate cartilage

DOI:  https://doi.org/10.1111/1750-3841.71013
Cell Mol Bioeng. 2026 Feb;19(1): 61-72

Melanoma/CSPG4-Enhanced Collagen-Mediated Contact Guidance Requires Mutant Active BRAF and the CSPG4 Core Protein Cytoplasmic Domain.

G Thrivikraman, J Yang, M Price, A Giubellino, J B McCarthy, R T Tranquillo.

   Introduction: Chondroitin sulfate proteoglycan-4 (CSPG4) is a transmembrane cell surface proteoglycan that promotes malignant progression in melanoma. Elevated CSPG4 expression in melanoma cells is associated with several malignant phenotypic properties, including increased tumor cell invasion, tumorigenic potential, and metastasis.
Methods: Magnetically aligned collagen gels with entrapped cells were used to model the aligned extracellular matrix in the tumor microenvironment and to identify the key role of CSPG4 in sensing contact guidance.
Results: The data show that CSPG4-expressing WM1552C Radial Growth Phase (RGP) melanoma cells exhibit enhanced contact guidance along with increased migration speed in contrast to paired counterparts that lack CSPG4. This required the presence of a pERK 1,2 phospho-acceptor site on the cytoplasmic tail of the core protein. Furthermore, short-term treatment of CSPG4-expressing cells with the clinically used mutant active BRAF inhibitor vemurafenib reduced both guidance and speed.
Conclusions: These findings support the role of CSPG4 overexpression and mutant active BRAF-in promoting increased contact guidance. The results are discussed in terms of expanding what is known about the potential tumor biology and clinical implications of CSPG4-related impact on malignant invasion during early phases of melanoma progression.
Supplementary Information: The online version contains supplementary material available at 10.1007/s12195-025-00882-x.

Keywords:  Aligned collagen; Chondroitin sulfate proteoglycan-4; Contact guidance; Melanoma

DOI:  https://doi.org/10.1007/s12195-025-00882-x
J Extracell Vesicles. 2026 Apr;15(4): e70266

Development of Anti-Inflammatory Extracellular Vesicles by Surface Expression of Syndecan-4.

Lijuan Yu, Markus Bergqvist, Kyong-Su Park, Cecilia Lässer, Jan Lötvall.

  The biological functions of extracellular vesicles (EVs) depend on their cellular source. Further, different subpopulations of EVs from the same cells carry different cargo, but differences in their biological functions are less understood. We here identify a very small EV subpopulation released by HEK293F cells (miniEVs). These EVs, in contrast to the larger EVs, were found to have anti-inflammatory properties. Quantitative proteomics identified a potential anti-inflammatory molecule, Syndecan-4 (SDC4), on the surface of the miniEVs, but not on larger EVs. We engineered HEK293F cells to overexpress SDC4, which results in the molecule being highly expressed in all EV subpopulations. Expression of SDC4, a proteoglycan, also increased the presence of heparan sulfate on the EV surface. Furthermore, these EVs were found to have potent anti-inflammatory effects in vitro, which heparinase treatment could slightly reduce. Furthermore, the SDC4 EVs showed anti-inflammatory effects in vivo in a model of peritonitis. We conclude that HEK293F miniEVs convey anti-inflammatory properties, and SDC4-expressing HEK293F-EV potentially could become an anti-inflammatory therapeutic.

Keywords:  exosomes; glycosylation; heparan sulfate; inflammation; nanomedicine; proteoglycan

DOI:  https://doi.org/10.1002/jev2.70266
Mol Med Rep. 2026 Jun;pii: 162. [Epub ahead of print]33(6):

Uremic toxin p‑cresyl sulfate enhances the calcification of aortic valvular interstitial cells via klotho/sirtuin‑1 signaling.

Shao-Jung Li, Tzu-Yu Cheng, Yu-Hsun Kao, Wei-Yu Chen, Cheng-Chih Chung, Nguyen Ngoc Trang, Pao-Huan Chen, Yi-Jen Chen.

  Calcific aortic valve disease (CAVD), a valvular heart disease with severe complications, is common in patients with chronic kidney disease (CKD). P‑cresyl sulfate (PCS) is a protein‑binding uremic toxin that induces chronic inflammation. Klotho and sirtuin‑1 (SIRT1) represent potential therapeutic agents for mitigating CKD‑induced vascular calcifications. We hypothesized that PCS could enhance valvular interstitial cell (VIC) calcification, which could be modulated by klotho/SIRT1 signaling. Alizarin Red S staining, western blotting and immunohistochemical analysis were performed in order to examine calcification and klotho/SIRT1 signaling in isolated porcine VICs following various 7‑day treatments. VIC treatments included incubation with PCS (10 and 100 µM), klotho (100 pM), the hypoxia‑inducible factor‑1α (HIF‑1α) inhibitor PX‑478 (0.5 µM) and the SIRT1 activator SRT1720 (1 mM). Furthermore, the present study established a PCS‑induced rat model of CKD and analyzed the effects of klotho on runt‑related transcription factor 2 (RUNX2) expression in rat aortic valves in vivo. Treatment with PCS increased VIC calcification, NF‑κB acetylation and the expression of RUNX2 and HIF‑1α expression but was shown to reduce klotho expression. Klotho supplementation attenuated the PCS‑induced enhancement of VIC calcification and mitigated PCS‑mediated increases in NF‑κB acetylation and RUNX2 expression. Additionally, the SIRT1 activator SRT1720 attenuated the PCS‑mediated enhancement of VIC calcification and was shown to upregulate klotho and downregulate RUNX2 in PCS‑treated VICs. Furthermore, the present study demonstrated that klotho supplementation mitigated CKD‑mediated RUNX2 upregulation in the aortic valves of PCS‑treated CKD model rats. The present study demonstrated that PCS induced VIC calcification by activating HIF‑1α signaling and downregulating klotho. Treatment with klotho or SRT1720 was shown to attenuate PCS‑mediated activation of the NF‑κB/RUNX2 signaling pathway, suggesting that these agents demonstrate notable therapeutic potential for targeting PCS‑induced CAVD.

Keywords:  calcific aortic valve disease; klotho; p‑cresol sulfate; runt‑related transcription factor 2; sirtuin‑1; valvular interstitial cell

DOI:  https://doi.org/10.3892/mmr.2026.13872
Int Immunopharmacol. 2026 Mar 27. pii: S1567-5769(26)00401-7. [Epub ahead of print]178 116556

Molecular pharmacology of sulfated polysaccharides from Sargassum fusiforme: mechanistic insights into HIV inhibition and immune modulation- a review.

Divya Vijayakumar.

   BACKGROUND: Sargassum fusiforme is a brown marine macroalga abundant in biologically active compounds, in particular, sulfated polysaccharides, phlorotannins, and polyphenols. These bioactives have shown potential effects as antiviral agent particularly against human immunodeficiency virus (HIV) by regulating viral entry as well as host immune responses.
PURPOSE: The purpose of this review is the critical summary of the molecular mechanisms of the anti-HIV activity of S. fusiforme bioactives and the assessment of their role in the regulation of immunity and inhibition of viruses.
STUDY DESIGN: Complete literature based literature review on molecular pharmacology, antiviral pathways and immunomodulatory pathways of S. fusiforme bioactives.
METHODS: Database searches were conducted to reveal relevant peer-reviewed studies. The information on structural properties, molecular targets, and biological activities of S. fusiforme-derived products was coordinated through in vitro, in vivo, and preclinical models.
RESULTS: Fucoidans of S. fusiforme react with the HIV gp120 and chemokine co-receptors (CCR5 and CXCR4), subsequently blocking viral entry. These compounds also regulate intracellular signaling cascades such as NF- κB, JAK/STAT, PI3K/ Akt and MAPK/ERK, which contribute to decreased viral replication and immune response. The degree of sulfaction and molecular weight are structural parameters that impact greatly on antiviral potency. Nevertheless, there is scanty evidence about pharmacokinetics, target validation and clinical translation.
CONCLUSION: The S. fusiforme are the bioactive compound which have multitarget antiviral and immunomodulatory potentials and demonstrate potential as adjunctive therapeutic agents in management of HIV. To confirm the applicability of their therapeutic use, further mechanistic studies, standardized characterization, and clinical research are required.

Keywords:  HIV; Sargassum fusiforme; fucoidan; immune modulation; marine bioactives; sulfated polysaccharides

DOI:  https://doi.org/10.1016/j.intimp.2026.116556