bims-supasi Biomed News
on Sulfation pathways and signalling
Issue of 2024–03–31
twelve papers selected by
Jonathan Wolf Mueller, University of Birmingham



  1. Mar Drugs. 2024 Feb 23. pii: 104. [Epub ahead of print]22(3):
      Sulfation is gaining increased interest due to the role of sulfate in the bioactivity of many polysaccharides of marine origin. Hence, sulfatases, enzymes that control the degree of sulfation, are being more extensively researched. In this work, a novel sulfatase (SulA1) encoded by the gene sulA1 was characterized. The sulA1-gene is located upstream of a chondroitin lyase encoding gene in the genome of the marine Arthrobacter strain (MAT3885). The sulfatase was produced in Escherichia coli. Based on the primary sequence, the enzyme is classified under sulfatase family 1 and the two catalytic residues typical of the sulfatase 1 family-Cys57 (post-translationally modified to formyl glycine for function) and His190-were conserved. The enzyme showed increased activity, but not improved stability, in the presence of Ca2+, and conserved residues for Ca2+ binding were identified (Asp17, Asp18, Asp277, and Asn278) in a structural model of the enzyme. The temperature and pH activity profiles (screened using p-nitrocatechol sulfate) were narrow, with an activity optimum at 40-50 °C and a pH optimum at pH 5.5. The Tm was significantly higher (67 °C) than the activity optimum. Desulfation activity was not detected on polymeric substrates, but was found on GalNAc4S, which is a sulfated monomer in the repeated disaccharide unit (GlcA-GalNAc4S) of, e.g., chondroitin sulfate A. The position of the sulA1 gene upstream of a chondroitin lyase gene and combined with the activity on GalNAc4S suggests that there is an involvement of the enzyme in the chondroitin-degrading cascade reaction, which specifically removes sulfate from monomeric GalNAc4S from chondroitin sulfate degradation products.
    Keywords:  N-acetylgalactosamine-4-O-sulfate; chondroitin sulfate; marine bacterium; sulfatase
    DOI:  https://doi.org/10.3390/md22030104
  2. Matrix Biol. 2024 Mar 26. pii: S0945-053X(24)00050-7. [Epub ahead of print]
      Cathepsin K (CtsK) is a cysteine protease with potent collagenase activity. CtsK is highly expressed by bone-resorbing osteoclasts and plays an essential role in resorption of bone matrix. Although CtsK is known to bind heparan sulfate (HS), the structural details of the interaction, and how HS regulates the biological functions of CtsK, remains largely unknown. In this report, we discovered that HS is a multifaceted regulator of the structure and function of CtsK. Structurally, HS forms a highly stable complex with CtsK and induces its dimerization. Co-crystal structures of CtsK with bound HS oligosaccharides reveal the location of the HS binding site and suggest how HS may support dimerization. Functionally, HS plays a dual role in regulating the enzymatic activity of CtsK. While it preserves the peptidase activity of CtsK by stabilizing its active conformation, it inhibits the collagenase activity of CtsK in a sulfation level-dependent manner. These opposing effects can be explained by our finding that the HS binding site is remote from the active site, which allows HS to specifically inhibit the collagenase activity without affecting the peptidase activity. At last, we show that structurally defined HS oligosaccharides effectively block osteoclast resorption of bone in vitro without inhibiting osteoclast differentiation, which suggests that HS-based oligosaccharide might be explored as a new class of selective CtsK inhibitor for many diseases involving exaggerated bone resorption.
    Keywords:  Osteoclasts; bone; inhibitor; oligosaccharide; resorption
    DOI:  https://doi.org/10.1016/j.matbio.2024.03.005
  3. Nat Commun. 2024 Mar 28. 15(1): 2723
      Integration of extracellular signals by neurons is pivotal for brain development, plasticity, and repair. Axon guidance relies on receptor-ligand interactions crosstalking with extracellular matrix components. Semaphorin-5A (Sema5A) is a bifunctional guidance cue exerting attractive and inhibitory effects on neuronal growth through the interaction with heparan sulfate (HS) and chondroitin sulfate (CS) glycosaminoglycans (GAGs), respectively. Sema5A harbors seven thrombospondin type-1 repeats (TSR1-7) important for GAG binding, however the underlying molecular basis and functions in vivo remain enigmatic. Here we dissect the structural basis for Sema5A:GAG specificity and demonstrate the functional significance of this interaction in vivo. Using x-ray crystallography, we reveal a dimeric fold variation for TSR4 that accommodates GAG interactions. TSR4 co-crystal structures identify binding residues validated by site-directed mutagenesis. In vitro and cell-based assays uncover specific GAG epitopes necessary for TSR association. We demonstrate that HS-GAG binding is preferred over CS-GAG and mediates Sema5A oligomerization. In vivo, Sema5A:GAG interactions are necessary for Sema5A function and regulate Plexin-A2 dependent dentate progenitor cell migration. Our study rationalizes Sema5A associated developmental and neurological disorders and provides mechanistic insights into how multifaceted guidance functions of a single transmembrane cue are regulated by proteoglycans.
    DOI:  https://doi.org/10.1038/s41467-024-46725-7
  4. J Mater Chem B. 2024 Mar 25.
      Due to the increasing aging population and the advancements in transcatheter aortic valve replacement (TAVR), the use of bioprosthetic heart valves (BHVs) in patients diagnosed with valvular disease has increased substantially. Commercially available glutaraldehyde (GA) cross-linked biological valves suffer from reduced durability due to a combination of factors, including the high cell toxicity of GA, subacute thrombus, inflammation and calcification. In this study, oxidized chondroitin sulfate (OCS), a natural polysaccharide derivative, was used to replace GA to cross-link decellularized bovine pericardium (DBP), carrying out the first crosslinking of DBP to obtain OCS-BP. Subsequently, the zwitterion radical copolymerization system was introduced in situ to perform double cross-linking to obtain double crosslinked BHVs with biomimetic modification (P(APM/MPC)-OCS-BP). P(APM/MPC)-OCS-BP presented enhanced mechanical properties, collagen stability and enzymatic degradation resistance due to double crosslinking. The ex vivo AV-shunt assay and coagulation factors test suggested that P(APM/MPC)-OCS-BP exhibited excellent anticoagulant and antithrombotic properties due to the introduction of P(APM/MPC). P(APM/MPC)-OCS-BP also showed good HUVEC-cytocompatibility due to the substantial reduction of its residual aldehyde group. The subcutaneous implantation also demonstrated that P(APM/MPC)-OCS-BP showed a weak inflammatory response due to the anti-inflammatory effect of OCS. Finally, in vivo and in vitro results revealed that P(APM/MPC)-OCS-BP exhibited an excellent anti-calcification property. In a word, this simple cooperative crosslinking strategy provides a novel solution to obtain BHVs with good mechanical properties, and HUVEC-cytocompatibility, anti-coagulation, anti-inflammatory and anti-calcification properties. It might be a promising alternative to GA-fixed BP and exhibited good prospects in clinical applications.
    DOI:  https://doi.org/10.1039/d4tb00074a
  5. Cell Mol Neurobiol. 2024 Mar 28. 44(1): 30
      Alzheimer's disease (AD) and traumatic brain injury (TBI) are major public health issues worldwide, with over 38 million people living with AD and approximately 48 million people (27-69 million) experiencing TBI annually. Neurodegenerative conditions are characterised by the accumulation of neurotoxic amyloid beta (Aβ) and microtubule-associated protein Tau (Tau) with current treatments focused on managing symptoms rather than addressing the underlying cause. Heparan sulfate proteoglycans (HSPGs) are a diverse family of macromolecules that interact with various proteins and ligands and promote neurogenesis, a process where new neural cells are formed from stem cells. The syndecan (SDC) and glypican (GPC) HSPGs have been implicated in AD pathogenesis, acting as drivers of disease, as well as potential therapeutic targets. Human mesenchymal stem cells (hMSCs) provide an attractive therapeutic option for studying and potentially treating neurodegenerative diseases due to their relative ease of isolation and subsequent extensive in vitro expansive potential. Understanding how HSPGs regulate protein aggregation, a key feature of neurodegenerative disorders, is essential to unravelling the underlying disease processes of AD and TBI, as well as any link between these two neurological disorders. Further research may validate HSPG, specifically SDCs or GPCs, use as neurodegenerative disease targets, either via driving hMSC stem cell therapy or direct targeting.
    Keywords:  Alzheimer’s disease; Amyloid beta; Heparan sulfate proteoglycan; Human mesenchymal stem cell; Neurogenesis; Traumatic brain injury
    DOI:  https://doi.org/10.1007/s10571-024-01463-8
  6. Sci Total Environ. 2024 Mar 24. pii: S0048-9697(24)02013-8. [Epub ahead of print] 171870
      In wastewater-based epidemiology (WBE), the selection of appropriate biomarkers presents a significant challenge. Recently, sulfated bisphenols have garnered attention as potential WBE biomarkers due to their increased stability in wastewater compared to glucuronide conjugates. This study aims to comprehensively assess the feasibility of employing sulfated BPA and BPS as WBE biomarkers by analyzing both WBE and human biomonitoring data. To conduct this research, wastewater samples were collected from six domestic wastewater treatment plants in Guangzhou, China, and urinary concentration of BPA and BPS were obtained from peer-reviewed literature. The results revealed that mean urinary concentrations of BPA and BPS, calculated using Monte Carlo simulations, significantly exceeded those reported in human biomonitoring studies. Furthermore, the per capita mass load ratio of sulfated BPA and BPS in human urine to the mass load in wastewater was found to be below 10 %. This outcome suggests that the excretion of BPA-S and BPS-S in urine does not make a substantial contribution to wastewater, hinting at the existence of other notable sources. Consequently, our study concludes that sulfated BPA-S and BPS-S are not suitable candidates as WBE biomarkers. This work provides a referenceable analytical framework for evaluating the feasibility of WBE biomarkers and emphasizes the necessity for caution when utilizing WBE to assess human exposure to chemicals.
    Keywords:  BPA; BPS; Sulfate conjugated; Wastewater analysis
    DOI:  https://doi.org/10.1016/j.scitotenv.2024.171870
  7. Essays Biochem. 2024 Mar 28. pii: EBC20230090. [Epub ahead of print]
      Oxysterol sulfates are emerging as key players in lipid homeostasis, inflammation and immunity. Despite this, knowledge on their basal levels in fluids, cells and tissues and any changes associated with age, gender and diet in health and disease; as well as their spatio-temporal distribution in cell membranes and organelles have been greatly hampered by the lack of commercially available pure synthetic standards. Expansion of the panel of pure oxysterol sulfates standards is pivotal to improve our understanding on the impact of oxysterol sulfates at the membrane level and their role in cellular events. While the clinical significance, biophysical implications and biological relevance of oxysterol sulfates in fluids, cells and tissues remains largely unknown, knowledge already gathered on the precursors of oxysterol sulfates (e.g. oxysterols and cholesterol sulfate) can be used to guide researchers on the most relevant aspects to search for when screening for oxysterol sulfates bioavailability in (patho)physiological conditions which are crucial in the design of biophysical and of cell-based assays. Herein, we provide a review on the brief knowledge involving oxysterol sulfate and an overview on the biophysical implications and biological relevance of oxysterols and cholesterol sulfate useful to redirect further investigations on the role of oxysterol sulfates in health and disease.
    Keywords:  biofluids; cholesterol sulfate; membrane fluidity; neurodegenerative diseases; oxysterols
    DOI:  https://doi.org/10.1042/EBC20230090
  8. Heliyon. 2024 Mar 30. 10(6): e28017
      Cholesteryl sulfate (CS) was quantitatively synthesized by microwave-assisted sulfonation of cholesterol followed by sodium exchange chromatography. In vitro effects of CS on human thrombin and other serine proteases of the coagulation and fibrinolysis processes were investigated using a series of biochemical and biophysical techniques. CS was found to inhibit thrombin with an IC50 value of 140.8 ± 21.8 μM at pH 7.4 and 25 ○C. Michaelis-Menten kinetics indicated that thrombin inhibition by CS is non-competitive (allosteric) in nature. Fluorescence-based binding studies indicated that CS binds to thrombin with a KD value of 180.9 ± 18.9 μM. Given the lack of competition with heparins and a hirudin peptide in competitive inhibition assays, it appears that CS does not bind to thrombin's exosites 1 or 2 and it rather recognizes a different allosteric exosite. CS was found to partially inhibit thrombin-mediated fibrinogen activation with an IC50 value of 175.5 ± 17.5 μM and efficacy of ∼26.0 ± 6.6%. Likewise, CS selectively doubled the activated partial thromboplastin time with EC2x of 521 μM. Interestingly, CS was found to also inhibit factors Xa and XIa as well as plasmin with IC50 values of ∼85-250 μM and efficacy of 94-100%. Nevertheless, CS most potently inhibited factor XIIa with an IC50 Value of ∼17 μM and efficacy of 60%. Surprisingly, CS did not inhibit factor IXa. These results encourage further in vitro and in vivo investigation of CS to better understand its (patho-) physiological roles in coagulation and hemostasis.
    Keywords:  Allostery; Cholesteryl sulfate; Clotting; Factor XIIa; Proteases; Thrombin
    DOI:  https://doi.org/10.1016/j.heliyon.2024.e28017
  9. Pharmaceuticals (Basel). 2024 Mar 14. pii: 371. [Epub ahead of print]17(3):
      Glycosaminoglycans (GAGs) are long linear polysaccharides found in every mammalian tissue. Previously thought only to be involved in cellular structure or hydration, GAGs are now known to be involved in cell signaling and protein modulation in cellular adhesion, growth, proliferation, and anti-coagulation. In this study, we showed that GAGs have an inhibitory effect on the IL-1β-stimulated mRNA expression of IL-6 and IL-8. Exogenous heparin (p < 0.0001), heparan (p < 0.0001), chondroitin (p < 0.049), dermatan (p < 0.0027), and hyaluronan (p < 0.0005) significantly reduced the IL-1β-induced IL-8 mRNA expression in HeLa cells. Exogenous heparin (p < 0.0001), heparan (p < 0.0001), and dermatan (p < 0.0027) also significantly reduced IL-1β-induced IL-6 mRNA expression in HeLa cells, but exogenous chondroitin and hyaluronan had no significant effect. The exogenous GAGs may reduce the transcription of these inflammatory cytokines through binding to TILRR, a co-receptor of IL-1R1, and block/reduce the interactions of TILRR with IL-1R1.
    Keywords:  IL-1β; IL-6; IL-8; glycosaminoglycans; heparin; inflammation
    DOI:  https://doi.org/10.3390/ph17030371
  10. Biomedicines. 2024 Feb 24. pii: 513. [Epub ahead of print]12(3):
      Hair loss is a common clinical condition connected with serious psychological distress and reduced quality of life. Hormones play an essential role in the regulation of the hair growth cycle. This review focuses on the hormonal background of hair loss, including pathophysiology, underlying endocrine disorders, and possible treatment options for alopecia. In particular, the role of androgens, including dihydrotestosterone (DHT), testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEA), and its sulfate (DHEAS), has been studied in the context of androgenetic alopecia. Androgen excess may cause miniaturization of hair follicles (HFs) in the scalp. Moreover, hair loss may occur in the case of estrogen deficiency, appearing naturally during menopause. Also, thyroid hormones and thyroid dysfunctions are linked with the most common types of alopecia, including telogen effluvium (TE), alopecia areata (AA), and androgenetic alopecia. Particular emphasis is placed on the role of the hypothalamic-pituitary-adrenal axis hormones (corticotropin-releasing hormone, adrenocorticotropic hormone (ACTH), cortisol) in stress-induced alopecia. This article also briefly discusses hormonal therapies, including 5-alpha-reductase inhibitors (finasteride, dutasteride), spironolactone, bicalutamide, estrogens, and others.
    Keywords:  5-alpha-reductase; alopecia areata; androgenetic alopecia; androgens; corticotropin-releasing hormone; estrogens; growth hormone; hair loss; polycystic ovary syndrome; thyroid hormones
    DOI:  https://doi.org/10.3390/biomedicines12030513
  11. Cells. 2024 Mar 08. pii: 481. [Epub ahead of print]13(6):
      Calcific Aortic Valve Disease (CAVD) is a significant concern for cardiovascular health and is closely associated with chronic kidney disease (CKD). Aortic valve endothelial cells (VECs) play a significant role in the onset and progression of CAVD. Previous research has suggested that uremic toxins, particularly indoxyl sulfate (IS), induce vascular calcification and endothelial dysfunction, but the effect of IS on valve endothelial cells (VECs) and its contribution to CAVD is unclear. Our results show that IS reduced human VEC viability and increased pro-calcific markers RUNX2 and alkaline phosphatase (ALP) expression. Additionally, IS-exposed VECs cultured in pro-osteogenic media showed increased calcification. Mechanistically, IS induced endothelial-to-mesenchymal transition (EndMT), evidenced by the loss of endothelial markers and increased expression of mesenchymal markers. IS triggered VEC inflammation, as revealed by NF-kB activation, and decreased integrin-linked kinase (ILK) expression. ILK overexpression reversed the loss of endothelial phenotype and RUNX2, emphasizing its relevance in the pathogenesis of CAVD in CKD. Conversely, a lower dose of IS intensified some of the effects in EndMT caused by silencing ILK. These findings imply that IS affects valve endothelium directly, contributing to CAVD by inducing EndMT and calcification, with ILK acting as a crucial modulator.
    Keywords:  calcific valve disease; cell transdifferentiation; chronic kidney disease; indoxyl sulfate; integrin-linked kinase; valve endothelial cells
    DOI:  https://doi.org/10.3390/cells13060481
  12. Cancers (Basel). 2024 Mar 13. pii: 1143. [Epub ahead of print]16(6):
      The role of the interaction with cell-surface glycosaminoglycans (GAGs) during in vivo HSV infection is currently unknown. The rationale of the current investigation was to improve the anticancer efficacy of systemically administered retargeted oHSVs (ReHVs) by decreasing their binding to GAGs, including those of endothelial cells, blood cells, and off-tumor tissues. As a proof-of-principle approach, we deleted seven amino acids critical for interacting with GAGs from the glycoprotein C (gC) of R-337 ReHV. The modification in the resulting R-399 recombinant prolonged the half-life in the blood of systemically administered R-399 and enhanced its biodistribution to tumor-positive lungs and to the tumor-negative liver. Ultimately, it greatly increased the R-399 efficacy against metastatic-like lung tumors upon IV administration but not against subcutaneous tumors upon IT administration. These results provide evidence that the increased efficacy seen upon R-399 systemic administration correlated with the slower clearance from the circulation. To our knowledge, this is the first in vivo evidence that the partial impairment of the gC interaction with GAGs resulted in a prolonged half-life of circulating ReHV, an increase in the amount of ReHV taken up by tissues and tumors, and, ultimately, an enhanced anticancer efficacy of systemically administered ReHV.
    Keywords:  HER2; chondroitin sulphate; gC; glycosaminoglycans; heparan sulphate; oncolytic herpes simplex virus; oncolytic virus; oncolytic virus biodistribution; retargeting; systemic oncolytic therapy
    DOI:  https://doi.org/10.3390/cancers16061143