bims-supasi 2023-12-24 papers

bims-supasi

Biomed News

on Sulfation pathways and signalling

Issue of 2023–12–24
thirteen papers selected by
Jonathan Wolf Mueller, University of Birmingham

Investigation of Glycosaminoglycans in Urine and Their Alteration in Patients with Juvenile Idiopathic Arthritis.
Loss of NDST1 N-sulfotransferase activity is associated with autosomal recessive intellectual disability.
Sulfation of furcellaran and its effect on hemocompatibility in vitro.
Bacterial pneumonia-induced shedding of epithelial heparan sulfate inhibits the bactericidal activity of cathelicidin in a murine model.
Steroid Conjugates and Their Physiological Role.
Investigation of Drug-Interaction Potential for Arthritis Dietary Supplements: Chondroitin Sulfate, Glucosamine, and Methylsulfonylmethane.
Structural Characterization and Anticoagulant Activities of a Keratan Sulfate-like Polysaccharide from the Sea Cucumber Holothuria fuscopunctata.
Analysis of vitamin D3-sulfate and 25-hydroxyvitamin D3-sulfate in breastmilk by LC-MS/MS.
Reference range of testosterone and dehydroepiandrosterone sulfate levels in women during reproductive age in the Iranian population.
The short-term effect of glucosamine-sulfate, nonanimal chondroitin-sulfate, and S-adenosylmethionine combination on ultrasonography findings, inflammation, pain, and functionality in patients with knee osteoarthritis: A pilot, double-blind, randomized, placebo-controlled clinical trial.
Effect of acute heparin administration on glycocalyx thickness and endothelial function in healthy younger adults.
Links between cholesteryl sulfate-dependent and -independent processes in the morphological and physiological changes of Entamoeba encystation.
Sulfated Galactans from Agarophytes: Review of Extraction Methods, Structural Features, and Biological Activities.

Biomolecules. 2023 Dec 02. pii: 1737. [Epub ahead of print]13(12):

Investigation of Glycosaminoglycans in Urine and Their Alteration in Patients with Juvenile Idiopathic Arthritis.

Elżbieta Lato-Kariakin, Kornelia Kuźnik-Trocha, Anna Gruenpeter, Katarzyna Komosińska-Vassev, Krystyna Olczyk, Katarzyna Winsz-Szczotka.

  (1) Background: In this study, we evaluated the modulation of urine glycosaminoglycans (GAGs), which resulted from etanercept (ETA) therapy in patients with juvenile idiopathic arthritis (JIA) in whom methotrexate therapy failed to improve their clinical condition. (2) Methods: The sulfated GAGs (sGAGs, by complexation with blue 1,9-dimethylmethylene), including chondroitin-dermatan sulfate (CS/DS) and heparan sulfate (HS), as well as non-sulfated hyaluronic acid (HA, using the immunoenzymatic method), were determined in the blood of 89 children, i.e., 30 healthy children and 59 patients with JIA both before and during two years of ETA treatment. (3) Results: We confirmed the remodeling of the urinary glycan profile of JIA patients. The decrease in the excretion of sGAGs (p < 0.05), resulting from a decrease in the concentration of the dominant fraction in the urine, i.e., CS/DS (p < 0.05), not compensated by an increase in the concentration of HS (p < 0.000005) and HA (p < 0.0005) in the urine of patients with the active disease, was found. The applied biological therapy, leading to clinical improvement in patients, at the same time, did not contribute to normalization of the concentration of sGAGs (p < 0.01) in the urine of patients, as well as CS/DS (p < 0.05) in the urine of sick girls, while it promoted equalization of HS and HA concentrations. These results indicate an inhibition of the destruction of connective tissue structures but do not indicate their complete regeneration. (4) Conclusions: The metabolisms of glycans during JIA, reflected in their urine profile, depend on the patient's sex and the severity of the inflammatory process. The remodeling pattern of urinary glycans observed in patients with JIA indicates the different roles of individual types of GAGs in the pathogenesis of osteoarticular disorders in sick children. Furthermore, the lack of normalization of urinary GAG levels in treated patients suggests the need for continued therapy and continuous monitoring of its effectiveness, which will contribute to the complete regeneration of the ECM components of the connective tissue and thus protect the patient against possible disability.

Keywords:  biological therapy; chondroitin sulfate; dermatan sulfate; heparan sulfate; hyaluronic acid; juvenile idiopathic arthritis; urine glycosaminoglycans

DOI:  https://doi.org/10.3390/biom13121737
Hum Mol Genet. 2023 Dec 21. pii: ddad203. [Epub ahead of print]

Loss of NDST1 N-sulfotransferase activity is associated with autosomal recessive intellectual disability.

Elham Khosrowabadi, Cécile Mignon-Ravix, Florence Riccardi, Pierre Cacciagli, Béatrice Desnous, Sabine Sigaudy, Mathieu Milh, Laurent Villard, Lena Kjellén, Florence Molinari.

  Intellectual Disability (ID) is the major cause of handicap, affecting nearly 3% of the general population, and is highly genetically heterogenous with more than a thousand genes involved. Exome sequencing performed in two independent families identified the same missense variant, p.(Gly611Ser), in the NDST1 (N-deacetylase/N-sulfotransferase member 1) gene. This variant had been previously found in ID patients of two other families but has never been functionally characterized. The NDST1 gene encodes a bifunctional enzyme that catalyzes both N-deacetylation and N-sulfation of N-acetyl-glucosamine residues during heparan sulfate (HS) biosynthesis. This step is essential because it influences the downstream enzymatic modifications and thereby determines the overall structure and sulfation degree of the HS polysaccharide chain. To discriminate between a rare polymorphism and a pathogenic variant, we compared the enzymatic properties of wild-type and mutant NDST1 proteins. We found that the p.(Gly611Ser) variant results in a complete loss of N-sulfotransferase activity while the N-deacetylase activity is retained. NDST1 shows the highest and the most homogeneous expression in the human cerebral structures compared to the other members of the NDST gene family. These results indicate that a loss of NDST1 N-sulfation activity is associated with impaired cognitive functions.

Keywords:  N-sulfation activity; NDST1; heparan sulfate; intellectual disability

DOI:  https://doi.org/10.1093/hmg/ddad203
Int J Biol Macromol. 2023 Dec 15. pii: S0141-8130(23)05739-2. [Epub ahead of print]258(Pt 1): 128840

Sulfation of furcellaran and its effect on hemocompatibility in vitro.

Kateřina Štěpánková, Kadir Ozaltin, Radka Gorejová, Hana Doudová, Eva Domincová Bergerová, Iveta Maskalová, Monika Stupavská, Pavel Sťahel, David Trunec, Jana Pelková, Miran Mozetič, Marian Lehocky.

  In this study, furcellaran (FUR) obtained from Furcellaria lumbricalis was firstly employed for sulfation via various methods, including SO3-pyridine (SO3∙Py) complex in different aprotic solvents, chlorosulfonic acid and sulfuric acid with a "coupling" reagent N,N'-Dicyclohexylcarbodiimide. Structural characterization through FT-IR, GPC, XPS and elemental analyses confirmed the successful synthesis of 6-O-sulfated FUR derivates characterized by varying degrees of sulfation (DS) ranging from 0.15 to 0.91 and molecular weight (Mw) spanning from12.5 kDa to 2.7 kDa. In vitro clotting assays, partial thromboplastin time (aPTT), thrombin time (TT), and prothrombin time (PT) underscored the essential role of sulfate esters in conferring anticoagulant activity whereas FUR prepared via chlorosulfonic acid with DS of 0.91 reached 311.4 s in aPPT showing almost 4-fold higher anticoagulant activity than native FUR at the concentration 2 mg/mL. MTT test showed all tested samples decreased cell viability in a dose dependent manner while all of them are non-cytotoxic up to the concentration of 0.1 mg/mL. Furthermore, sulfated derivates deposited onto polyethylene terephthalate surface presented substantial decrease in platelet adhesion, as well as absence of the most activated platelet stages. These findings support the pivotal role of O-6 FUR sulfates in enhancing hemocompatibility and provide valuable insights for a comparative assessment of effective sulfating approaches.

Keywords:  Anticoagulant; Furcellaran; Hemocompatibility; Platelet adhesion; Seaweed polysaccharide; Sulfation

DOI:  https://doi.org/10.1016/j.ijbiomac.2023.128840
Am J Physiol Lung Cell Mol Physiol. 2023 Dec 19.

Bacterial pneumonia-induced shedding of epithelial heparan sulfate inhibits the bactericidal activity of cathelicidin in a murine model.

Evan P Zehr, Christopher L Erzen, Kaori Oshima, Christophe J Langouët-Astrié, Wells B LaRiviere, Deling Shi, Fuming Zhang, Bruce D McCollister, Samuel L Windham, Alicia N Rizzo, Julie A Bastarache, Alexander R Horswill, Eric P Schmidt, Jakub M Kwiecinski, James F Colbert.

  Primary bacterial pneumonia is a common clinical syndrome leading to significant morbidity and mortality worldwide. In the current study, we investigate a novel, multidirectional relationship between the pulmonary epithelial glycocalyx and antimicrobial peptides in the setting of Methicillin Resistant Staphylococcus aureus (MRSA) pneumonia. Using an in vivo pneumonia model, we demonstrate that highly-sulfated heparan sulfate oligosaccharides (HS) are shed into the airspaces in response to MRSA pneumonia. In vitro, these HS oligosaccharides do not directly alter MRSA growth or gene transcription. However, in the presence of an antimicrobial peptide (cathelicidin), increasing concentrations of HS inhibit the bactericidal activity of cathelicidin against MRSA as well as other nosocomial pneumonia pathogens (Klebsiella pneumoniae and Pseudomonas aeruginosa) in a dose-dependent fashion. Surface plasmon resonance shows avid binding between HS and cathelicidin with a dissociation constant of 0.13 micromolar. These findings highlight a complex relationship in which shedding of airspace HS may hamper host defenses against nosocomial infection via neutralization of antimicrobial peptides. These findings may inform future investigation into novel therapeutic targets designed to restore local innate immune function in patients suffering from primary bacterial pneumonia.

Keywords:  Antimicrobial Peptides; Cathelicidin; Heparan Sulfate; Pneumonia; Staphylococcus aureus

DOI:  https://doi.org/10.1152/ajplung.00178.2023
Physiol Res. 2023 Dec 17. 72(S4): S317-S322

Steroid Conjugates and Their Physiological Role.

J Vítků, R Hampl.

While there are hundreds of synthetic steroids conjugates with acids, sugars, proteins and other molecules, only two types of conjugates occur in living organisms, namely sulfates and glucuronides. Steroid glucuronidation in the human liver is the main mechanism controlling the levels and biological activity of unconjugated hormones, and glucuronides are their main excretion products. This process is generally irreversible. On the other hand, sulfates possess their own biological activity that differs from that of the unconjugated steroid, emphasizing the importance of steroid sulfatases and sulfotransferases. Due to their negative charge, steroid sulfates cannot cross the blood-cell barrier and have to use transporters. Their efflux is mediated by specific transporters of the ATP binding cassette protein group, which thus are further factors controlling their physiological effects. Steroid sulfates, especially dehydroepiandrosterone sulfate (DHEAS) are neuroactive steroids, with well-known effects as allosteric modulators of some neurotransmitter receptors, functioning as ion channels, such as gamma-aminobutyric acid, type A (GABAA) receptors or N-methyl-D-aspartate (NMDA) receptors. In this minireview, we highlight some recent findings of non-genomic steroid sulfate actions through specific G-protein coupled receptors (GPCR), which we believe show the way of further research. A few studies have even indicated that sulfates such as DHEAS may even indirectly regulate gene expression via ligand binding to the membrane receptor and, through G-protein and second messenger formation, activate proteins like cAMP Regulated Elements Binding protein (CREB), which then binds to regulated DNA elements of the expressed gene, in a "classical" genomic effect.
Molecules. 2023 Dec 13. pii: 8068. [Epub ahead of print]28(24):

Investigation of Drug-Interaction Potential for Arthritis Dietary Supplements: Chondroitin Sulfate, Glucosamine, and Methylsulfonylmethane.

Su Min Kim, So Young Jo, Ho-Young Park, Yu Ra Lee, Jun Sang Yu, Hye Hyun Yoo.

  Osteoarthritis is one of the leading conditions that promote the consumption of these dietary supplements. Chondroitin sulfate, glucosamine, and methylsulfonylmethane are among the prominent alternative treatments for osteoarthritis. In this study, these dietary supplements were incubated with cytochrome P450 isozyme-specific substrates in human liver microsomes, and the formation of marker metabolites was measured to investigate their inhibitory potential on cytochrome P450 enzyme activities. The results revealed no significant inhibitory effects on seven CYPs, consistent with established related research data. Therefore, these substances are anticipated to have a low potential for cytochrome P450-mediated drug interactions with osteoarthritis medications that are likely to be co-administered. However, given the previous reports of interaction cases involving glucosamine, caution is advised regarding dietary supplement-drug interactions.

Keywords:  chondroitin sulfate; cytochrome P450; glucosamine; methylsulfonylmethane; osteoarthritis

DOI:  https://doi.org/10.3390/molecules28248068
Mar Drugs. 2023 Dec 08. pii: 632. [Epub ahead of print]21(12):

Structural Characterization and Anticoagulant Activities of a Keratan Sulfate-like Polysaccharide from the Sea Cucumber Holothuria fuscopunctata.

Ru Chen, Weili Wang, Ronghua Yin, Ying Pan, Chen Xu, Na Gao, Xiaodong Luo, Jinhua Zhao.

  A sulfated polysaccharide (AG) was extracted and isolated from the sea cucumber H. fuscopunctata, consisting of GlcNAc, GalNAc, Gal, Fuc and lacking any uronic acid residues. Importantly, several chemical depolymerization methods were used to elucidate the structure of the AG through a bottom-up strategy. A highly sulfated galactose (oAG-1) and two disaccharides labeled with 2,5-anhydro-D-mannose (oAG-2, oAG-3) were obtained from the deaminative depolymerized product along with the structures of the disaccharide derivatives (oAG-4~oAG-6) identified from the free radical depolymerized product, suggesting that the repeating building blocks in a natural AG should comprise the disaccharide β-D-GalS-1,4-D-GlcNAc6S. The possible disaccharide side chains (bAG-1) were obtained with mild acid hydrolysis. Thus, a natural AG may consist of a keratan sulfate-like (KS-like) glycosaminoglycan with diverse modifications, including the sulfation types of the Gal residue and the possible disaccharide branches α-D-GalNAc4S6S-1,2-α/β-L-Fuc3S linked to the KS-like chain. Additionally, the anticoagulant activities of the AG and its depolymerized products (dAG1-9) were evaluated in vitro using normal human plasma. The AG could prolong activated partial thromboplastin time (APTT) in a dose-dependent manner, and the activity potency was positively related to the chain length. The AG and dAG1-dAG3 could prolong thrombin time (TT), while they had little effect on prothrombin time (PT). The results indicate that the AG could inhibit the intrinsic and common coagulation pathways.

Keywords:  aminoglycan; anticoagulant activity; depolymerization; keratan sulfate; oligosaccharides; structural features

DOI:  https://doi.org/10.3390/md21120632
J Chromatogr B Analyt Technol Biomed Life Sci. 2023 Dec 06. pii: S1570-0232(23)00364-1. [Epub ahead of print]1232 123954

Analysis of vitamin D3-sulfate and 25-hydroxyvitamin D3-sulfate in breastmilk by LC-MS/MS.

Carmen J Reynolds, Roy B Dyer, Brady A Vizenor, Nicholas J Koszewski, Ravinder J Singh, Tom D Thacher.

  Sulfated metabolites of vitamin D have been suggested to be in breastmilk, although current methods to measure sulfated vitamin D compounds in breastmilk by liquid chromatography-tandem mass spectrometry (LC-MS/MS) have not adequately accounted for increased aqueous solubility of these sulfated metabolites. The purpose of this study was to generate a method of LC-MS/MS for measuring vitamin D3-3-sulfate (VitD3-S) and 25-hydroxyvitamin D3-3-sulfate (25OHD3-S) specifically in human breastmilk. The resulting method uses methanol to precipitate protein and solid phase extraction to prepare the samples for LC-MS/MS. The limits of quantification for analytes in solvent were 0.23 ng/mL VitD3-S and 0.2 ng/mL 25OHD3-S. Various experiments observed concentrations ranging 0.53 to 1.7 ng/mL VitD3-S and ≤ 0.29 ng/mL 25OHD3-S. Both analytes were present in aqueous skim milk, demonstrating the enhanced aqueous solubility of these vitamin D sulfates. In conclusion, we describe an effective method for measuring VitD3-S and 25OHD3-S in breastmilk by LC-MS/MS.

Keywords:  25-Hydroxyvitamin D; Mass Spectrometry; Milk; Sulfate; Vitamin D

DOI:  https://doi.org/10.1016/j.jchromb.2023.123954
J Res Med Sci. 2023 ;28 69

Reference range of testosterone and dehydroepiandrosterone sulfate levels in women during reproductive age in the Iranian population.

Rokhsareh Meamar, Awat Feizi, Ashraf Aminorroaya, Masoud Amini, Bijan Iraj, Maryam Heidarpour.

   Backgrounds: To determine the average cutoff values of serum-free and total testosterone (FT, TT) and dehydroepiandrosterone sulfate (DHEAS) among healthy premenopausal women.
Materials and Methods: Participants were women aged 18-55 years without signs and symptoms of hyperandrogenism (n = 489). Participants if Ferriman-Gallwey (FG) scores between 6 and 8 were considered a group located in the upper spectrum related to the normal hirsutism score (n = 30). DHEAS, TT, and FT levels were compared between different populations. Upper limits of 97.5 and 95 and lower limits of 5 and 2.5 percentiles were calculated to provide the reference intervals for DHEA, TT, and FT in the total sample and in the population with FG 6-8.
Results: In the total population, the mean ± standard deviation (SD) serum FT, TT, and DHEAS levels were 1.40 ± 0.63 pg/mL, 0.42 ± 0.17 ng/mL, and 1.5 ± 0.97 µg/ml, respectively. The cutoff values of FT at 1.35 and TT at 0.49 were obtained for differentiating the patients with FG 6-8 scores from the normal population, with the corresponding specificity of 0.60, the sensitivity of 0.67, and area under the ROC curve (AUC) (confidence interval 95%) of 0.63 (0.52-0.73), P = 0.01 and 0.68 (0.58-0.78) P = 0.001, respectively.
Conclusions: In our study, the mean ± SD serum FT level was 1.40 ± 0.63 pg/mL, the TT level was 0.42 ± 0.17 ng/mL, and the DHEAS level was 1.5 ± 0.97 µg/ml, in premenopausal women between 18 and 49 years of age. Furthermore, in a population with FG 6-8 score, a cutoff value of FT at 1.35 and TT at 0.49 was obtained. Although the irregular menstrual cycle did not change the reference range when compared with the normal group.

Keywords:  androgen; reference range; reproductive; testosterone

DOI:  https://doi.org/10.4103/jrms.jrms_100_22
Arch Rheumatol. 2023 Dec;38(4): 521-541

The short-term effect of glucosamine-sulfate, nonanimal chondroitin-sulfate, and S-adenosylmethionine combination on ultrasonography findings, inflammation, pain, and functionality in patients with knee osteoarthritis: A pilot, double-blind, randomized, placebo-controlled clinical trial.

Zoran Veličković, Slavica Pavlov Dolijanović, Nikola Stojanović, Saša Janjić, Ljiljana Kovačević, Ivan Soldatović, Goran Radunović.

   Objectives: This study aimed to investigate the efficacy of glucosamine-sulfate (GS), nonanimal chondroitin-sulfate (naCS), and S-adenosylmethionine (SAMe) combination on ultrasound findings, inflammation, pain, and functionality in knee osteoarthritis.
Patients and methods: In the prospective, randomized, double-blind, placebo-controlled pilot study conducted between August 2019 and November 2019, 120 participants (28 males, 92 females; mean age: 66.4±7.9 years; range, 42.4 to 74.5 years) were randomized at a 1:1:1 ratio to the placebo group, the first experimental group (a combination of GS, naCS, and SAMe was administered to the experimental groups. The first experimental group received 375 mg of GS, 300 mg of naCS, and 100 mg of SAMe, whereas the second experimental group received 750 mg of GS, 600 mg of naCS, and 200 mg of SAMe). Laboratory (erythrocyte sedimentation rate, C-reactive protein, tumor necrosis factor alpha, interleukin [IL]-1β, IL-6, IL-17), clinical (Visual Analog Scale [VAS], short form health survey [SF-36], the Western Ontario and McMaster Universities Arthritis Index [WOMAC], and the Tegner Lysholm Knee Scoring Scale [TLKS]), and musculoskeletal ultrasound (MSUS) assessments were performed at baseline and after three and six months.
Results: A minor increase was observed in the second experimental group after six months using ultrasonography to evaluate articular cartilage thickness (p<0.05). The investigational product's superiority in reducing osteoarthritis ultrasonographic findings was not proven. A moderately negative association was found between cartilage thickness and VAS scores at baseline (ρ=-0.36, p<0.01), while the presence of massive osteophytes on MSUS showed a low to moderate association with all clinical outcomes. There was no difference in the delta changes between groups for the VAS, TLKS, WOMAC, and SF-36. The only serum inflammatory marker outside the reference range was IL-1β, but no significant changes were observed after six months.
Conclusion: According to the results of our investigation, treatment for knee osteoarthritis should be evaluated using more objective outcomes. The most important conclusion of our study is that IP may result in a slight increase in articular cartilage thickness, which was associated with a decrease in pain intensity at baseline. Clarification of the potential influence of this combination on radiographic progression and laboratory markers of inflammation requires further exploration.

Keywords:  Cartilage; chondroitin-sulfate; glucosamine-sulfate; knee osteoarthritis; s-adenosylmethionine.

DOI:  https://doi.org/10.46497/ArchRheumatol.2023.9994
J Appl Physiol (1985). 2023 Dec 21.

Effect of acute heparin administration on glycocalyx thickness and endothelial function in healthy younger adults.

Colin J Gimblet, Jackson W Ernst, Kyle D Bos, Amy K Stroud, Anthony J Donato, Diana I Jalal, Gary L Pierce.

  The endothelial glycocalyx is a dynamic, gel like layer that is critical to normal vascular endothelial function. Heparin impairs the endothelial glycocalyx and reduces vascular endothelial function in a murine model, however this has yet to be tested in healthy humans. We hypothesized that a single bolus dose of heparin would increase circulating glycocalyx components and decrease endothelial glycocalyx thickness resulting in blunted brachial artery vasodilation in healthy younger adults. Healthy adults (n=19, aged 18-39 years, 47% female) underwent measurements of the endothelial glycocalyx and vascular endothelial function at baseline and after a single bolus 5000U dose of heparin. The glycocalyx components syndecan-1 and heparan sulfate were measured from plasma samples using enzyme linked immunosorbent assays. Glycocalyx thickness was determined as perfused boundary region (PBR) in sublingual microvessels using the GlycoCheck. Endothelial function was measured via ultrasonography and quantified as brachial artery flow-mediated dilation (FMD). Following acute heparin administration, there was no increase in syndecan-1 or heparan sulfate (P=0.90 & P=0.49, respectively). Additionally, there was no change in PBR 4-7µm (P=0.55), PBR 10-25µm (P=0.63), or 4-25µm (P=0.49) after heparin treatment. Furthermore, we did not observe a change in FMDmm (P=0.23), FMD% (P=0.35) or plasma nitrite concentrations (P=0.10) in response to heparin. Finally, time to peak dilation and peak FMD normalized to shear stress were unchanged following heparin (P=0.59 & P=0.21, respectively). Our pilot study suggests that a single bolus intravenous dose of heparin does not result in endothelial glycocalyx degradation or vascular endothelial dysfunction in healthy younger adults.

Keywords:  Endothelial Function; Glycocalyx; Heparin

DOI:  https://doi.org/10.1152/japplphysiol.00767.2023
Parasitol Int. 2023 Dec 14. pii: S1383-5769(23)00122-8. [Epub ahead of print] 102844

Links between cholesteryl sulfate-dependent and -independent processes in the morphological and physiological changes of Entamoeba encystation.

Fumika Mi-Ichi, Shinjiro Hamano, Hiroki Yoshida.

  The protozoan parasite Entamoeba histolytica causes amoebiasis, a global public health problem. Amoebiasis is solely transmitted by cysts that are produced from proliferative trophozoites by encystation in the large intestine of humans. During encystation, various metabolites, pathways, and cascades sequentially orchestrate the morphological and physiological changes required to produce cysts. Cholesteryl sulfate (CS) has recently been revealed to be among the key molecules that control the morphological and physiological changes of encystation by exerting pleiotropic effects. CS promotes the rounding of encysting Entamoeba cells and maintains this spherical morphology as encysting cells are surrounded by the cyst wall, a prerequisite for resistance against environmental stresses. CS is also involved in the development of membrane impermeability, another prerequisite for resistance. The initiation of cyst wall formation is, however, CS-independent. Here, we overview CS-dependent and -independent processes during encystation and discuss their functional linkage. We also discuss a potential transcriptional cascade that controls the processes necessary to produce dormant Entamoeba cysts.

Keywords:  Cholesteryl sulfate; Encystation; Entamoeba; Transcriptional control; Transmission

DOI:  https://doi.org/10.1016/j.parint.2023.102844
Biomolecules. 2023 Dec 05. pii: 1745. [Epub ahead of print]13(12):

Sulfated Galactans from Agarophytes: Review of Extraction Methods, Structural Features, and Biological Activities.

Khosook Chumsook, Jantana Praiboon, Xiaoting Fu.

  Agarophytes are important seaweeds of the Rhodophyta type, which have been highly exploited for industrial use as sources of a widely consumed polysaccharide of agar. In addition to that, sulfated galactans (SGs) from agarophytes, which consist of various functional sulfate groups, have attracted the attention of scientists in current studies. SGs possess various biological activities, such as anti-tumor, anticoagulant, anti-inflammatory, antioxidant, anti-obesity, anti-diabetic, anti-microbial, anti-diarrhea, and gut microbiota regulation properties. Meanwhile, the taxonomy, ecological factors, i.e., environmental factors, and harvest period, as well as preparation methods, i.e., the pretreatment, extraction, and purification conditions, have been found to influence the chemical compositions and fine structures of SGs, which have, further, been shown to have an impact on their biological activities. However, the gaps in the knowledge of the properties of SGs due to the above complex factors have hindered their industrial application. The aim of this paper is to collect and systematically review the scientific evidence about SGs and, thus, to pave the way for broader and otherwise valuable industrial applications of agarophytes for human enterprise. In the future, this harvested biomass could be sustainably used not only as a source of agar production but also as natural materials in functional food and pharmaceutical industries.

Keywords:  agarophytes; bioactivity; extraction; structure; sulfated galactans

DOI:  https://doi.org/10.3390/biom13121745