bims-supasi 2024-02-18 papers

bims-supasi

Biomed News

on Sulfation pathways and signalling

Issue of 2024–02–18
fiveteen papers selected by
Jonathan Wolf Mueller, University of Birmingham

Structural and mechanistic characterization of bifunctional heparan sulfate N-deacetylase-N-sulfotransferase 1.
SARS-CoV-2 spike protein-ACE2 interaction increases carbohydrate sulfotransferases and reduces N-acetylgalactosamine-4-sulfatase by p38 MAPK.
Complex roles for sulfation in the toxicities of polychlorinated biphenyls.
Crystal structure of tick tyrosylprotein sulfotransferase reveals the activation mechanism of the tick anticoagulant protein madanin.
Dextran sulfate acting as a chaperone-like component on inhibition of amorphous aggregation and enhancing thermal stability of ovotransferrin.
Effect of indoxyl sulfate on the morphology and function of the thyroid gland - ex vivo studies in rabbits.
The European biological variation study (EuBIVAS): Biological variation data for testosterone, follicle stimulating hormone, prolactin, luteinizing hormone and dehydroepiandrosterone sulfate in men.
Is it useful to measure DHEAS levels in PCOS?
Host-microbiome orchestration of the sulfated metabolome.
Human induced pluripotent stem cells are resistant to human cytomegalovirus infection primarily at the attachment level due to the reduced expression of cell-surface heparan sulfate.
The co-receptor Tspan12 directly captures Norrin to promote ligand-specific β-catenin signaling.
Tyrosine-sulfated peptide hormone induces flavonol biosynthesis to control elongation and differentiation in Arabidopsis primary root.
Sulfation of hyaluronic acid reconfigures the mechanistic pathway of bone morphogenetic protein-2 aggregation.
Heparin-Induced Thrombocytopenia: A Case Report Four Years After the Initiation of Maintenance Hemodialysis.
Circulating endogenous sex steroids and risk of differentiated thyroid carcinoma in men and women.

Nat Commun. 2024 Feb 13. 15(1): 1326

Structural and mechanistic characterization of bifunctional heparan sulfate N-deacetylase-N-sulfotransferase 1.

Courtney J Mycroft-West, Sahar Abdelkarim, Helen M E Duyvesteyn, Neha S Gandhi, Mark A Skidmore, Raymond J Owens, Liang Wu.

Heparan sulfate (HS) polysaccharides are major constituents of the extracellular matrix, which are involved in myriad structural and signaling processes. Mature HS polysaccharides contain complex, non-templated patterns of sulfation and epimerization, which mediate interactions with diverse protein partners. Complex HS modifications form around initial clusters of glucosamine-N-sulfate (GlcNS) on nascent polysaccharide chains, but the mechanistic basis underpinning incorporation of GlcNS itself into HS remains unclear. Here, we determine cryo-electron microscopy structures of human N-deacetylase-N-sulfotransferase (NDST)1, the bifunctional enzyme primarily responsible for initial GlcNS modification of HS. Our structures reveal the architecture of both NDST1 deacetylase and sulfotransferase catalytic domains, alongside a non-catalytic N-terminal domain. The two catalytic domains of NDST1 adopt a distinct back-to-back topology that limits direct cooperativity. Binding analyses, aided by activity-modulating nanobodies, suggest that anchoring of the substrate at the sulfotransferase domain initiates the NDST1 catalytic cycle, providing a plausible mechanism for cooperativity despite spatial domain separation. Our data shed light on key determinants of NDST1 activity, and describe tools to probe NDST1 function in vitro and in vivo.

DOI: https://doi.org/10.1038/s41467-024-45419-4
Signal Transduct Target Ther. 2024 Feb 14. 9(1): 39

SARS-CoV-2 spike protein-ACE2 interaction increases carbohydrate sulfotransferases and reduces N-acetylgalactosamine-4-sulfatase by p38 MAPK.

Sumit Bhattacharyya, Joanne K Tobacman.

Immunostaining in lungs of patients who died with COVID-19 infection showed increased intensity and distribution of chondroitin sulfate and decline in N-acetylgalactostamine-4-sulfatase (Arylsulfatase B; ARSB). To explain these findings, human small airway epithelial cells were exposed to the SARS-CoV-2 spike protein receptor binding domain (SPRBD) and transcriptional mechanisms were investigated. Phospho-p38 MAPK and phospho-SMAD3 increased following exposure to the SPRBD, and their inhibition suppressed the promoter activation of the carbohydrate sulfotransferases CHST15 and CHST11, which contributed to chondroitin sulfate biosynthesis. Decline in ARSB was mediated by phospho-38 MAPK-induced N-terminal Rb phosphorylation and an associated increase in Rb-E2F1 binding and decline in E2F1 binding to the ARSB promoter. The increases in chondroitin sulfotransferases were inhibited when treated with phospho-p38-MAPK inhibitors, SMAD3 (SIS3) inhibitors, as well as antihistamine desloratadine and antibiotic monensin. In the mouse model of carrageenan-induced systemic inflammation, increases in phospho-p38 MAPK and expression of CHST15 and CHST11 and declines in DNA-E2F binding and ARSB expression occurred in the lung, similar to the observed effects in this SPRBD model of COVID-19 infection. Since accumulation of chondroitin sulfates is associated with fibrotic lung conditions and diffuse alveolar damage, increased attention to p38-MAPK inhibition may be beneficial in ameliorating Covid-19 infections.

DOI: https://doi.org/10.1038/s41392-024-01741-3
Crit Rev Toxicol. 2024 Feb 16. 1-31

Complex roles for sulfation in the toxicities of polychlorinated biphenyls.

Michael W Duffel, Hans-Joachim Lehmler.

  Polychlorinated biphenyls (PCBs) are persistent organic toxicants derived from legacy pollution sources and their formation as inadvertent byproducts of some current manufacturing processes. Metabolism of PCBs is often a critical component in their toxicity, and relevant metabolic pathways usually include their initial oxidation to form hydroxylated polychlorinated biphenyls (OH-PCBs). Subsequent sulfation of OH-PCBs was originally thought to be primarily a means of detoxication; however, there is strong evidence that it may also contribute to toxicities associated with PCBs and OH-PCBs. These contributions include either the direct interaction of PCB sulfates with receptors or their serving as a localized precursor for OH-PCBs. The formation of PCB sulfates is catalyzed by cytosolic sulfotransferases, and, when transported into the serum, these metabolites may be retained, taken up by other tissues, and subjected to hydrolysis catalyzed by intracellular sulfatase(s) to regenerate OH-PCBs. Dynamic cycling between PCB sulfates and OH-PCBs may lead to further metabolic activation of the resulting OH-PCBs. Ultimate toxic endpoints of such processes may include endocrine disruption, neurotoxicities, and many others that are associated with exposures to PCBs and OH-PCBs. This review highlights the current understanding of the complex roles that PCB sulfates can have in the toxicities of PCBs and OH-PCBs and research on the varied mechanisms that control these roles.

Keywords:  OH-PCB; PCB; PCB sulfate; STS; SULT; Sulfation; detoxication; endocrine disruption; inhibition; metabolic activation; neurotoxicity; polychlorinated biphenyl; sulfatase; sulfotransferase; toxicity

DOI:  https://doi.org/10.1080/10408444.2024.2311270
J Biol Chem. 2024 Feb 12. pii: S0021-9258(24)00124-8. [Epub ahead of print] 105748

Crystal structure of tick tyrosylprotein sulfotransferase reveals the activation mechanism of the tick anticoagulant protein madanin.

Misa Yoshimura, Takamasa Teramoto, Hirai Asano, Yuka Iwamoto, Mariko Kondo, Etsuko Nishimoto, Yoshimitsu Kakuta.

  Ticks pose a substantial public health risk as they transmit various pathogens. This concern is related to the adept blood-sucking strategy of ticks, underscored by the action of the anticoagulant, madanin, which is known to exhibit approximately 1000-fold increase in anticoagulant activity following sulfation of its two tyrosine residues, Tyr51 and Tyr54. Despite this knowledge, the molecular mechanism underlying sulfation by tick tyrosylprotein sulfotransferase (TPST) remains unclear. In this study, we successfully prepared tick TPST as a soluble recombinant enzyme. We clarified the method by which this enzyme proficiently sulfates tyrosine residues in madanin. Biochemical analysis using a substrate peptide based on madanin and tick TPST, along with the analysis of the crystal structure of the complex and docking simulations, revealed a sequential sulfation process. Initial sulfation at the Tyr51 site augments binding, thereby facilitating efficient sulfation at Tyr54. Beyond direct biochemical implications, these findings considerably improve our understanding of tick blood-sucking strategies. Furthermore, combined with the utility of modified tick TPST, our findings may lead to the development of novel anticoagulants, promising avenues for thrombotic disease intervention and advancements in the field of public health.

Keywords:  X-ray crystallography; anticoagulant protein; madanin; tick; tyrosine sulfation; tyrosylprotein sulfotransferase

DOI:  https://doi.org/10.1016/j.jbc.2024.105748
Food Chem. 2024 Feb 12. pii: S0308-8146(24)00369-8. [Epub ahead of print]445 138720

Dextran sulfate acting as a chaperone-like component on inhibition of amorphous aggregation and enhancing thermal stability of ovotransferrin.

Fengguang Pan, Xinling Wu, Lingling Gong, Haojie Xu, Yixin Yuan, Jinming Lu, Ting Zhang, Jingbo Liu, Xiaomin Shang.

  The tendency of ovotransferrin (OVT) to unfold and aggregate under 60 °C severely restricted sterilization temperature during egg processing. Searching for efficient strategies to improve OVT thermal stability is essential for improving egg product quality and processing suitability. Here, we investigated the effect of sulfate polysaccharide (dextran sulfate, DS) on heat-induced aggregation of OVT. We found that DS can effectively suppress amorphous aggregation of OVT at pH 7.0 after heating. Strikingly, the addition of 5 µM DS fully suppressed insoluble aggregates formation of 0.5 mg/mL OVT. Structure analysis confirmed that DS preserves nearly the entire secondary and tertiary structure of OVT during heating. The steric hindrance effect arising from strong electrostatic interactions between OVT and DS, coupled with reduced OVT hydrophobicity, is the underlying mechanism in suppressing protein-protein interactions, thus enhancing thermal stability. These findings suggest DS could act as protein stabilizers and chaperones, enhancing the thermostability of heat-sensitive proteins.

Keywords:  Chaperone-like activity; Ovotransferrin; Soluble aggregates; Sulfated polysaccharide; Thermal stability

DOI:  https://doi.org/10.1016/j.foodchem.2024.138720
J Physiol Pharmacol. 2023 Dec;74(6):

Effect of indoxyl sulfate on the morphology and function of the thyroid gland - ex vivo studies in rabbits.

M Chmurska, A Galuszka, P Pawlicki, M Zarzycka, A Sechman, A Grzegorzewska, P Niedbala, M Kotula-Balak.

Indoxyl sulfates are uremic indolic toxins known to participate in the pathogenesis of cardiovascular diseases during chronic kidney disease in humans and some animal species. However, nothing is known about the indoxyl sulfate effect on the thyroid gland which is especially responsible for the general organism metabolism. This study determines the morpho-functional status of the thyroid gland after exposure to indoxyl sulfate (10, 25, and 50 mM) with the use of an ex vivo system and rabbit (n=10) as an experimental model thyroid gland histology, immunoexpression of thyrotropin receptor (TSHR), and concentrations of thyroxine (T4) and triiodothyronine (T3) were evaluated. Statistical analyses were performed using one-way analysis of the variance (ANOVA) followed by Tukey's post hoc comparison test. Minor alterations in thyroid tissue structure e.g. very rare exfoliated epithelial cells, condensed colloid fluid, or slight loosening of the epithelium were found. In addition, modulated dose dependent-expression of TSHR (p<0.01, p<0.001) together with a decreased level of T4 and T3 (p<0.001, p<0.01) exception of an increased level of T4 after the middle dose of indoxyl sulfate were revealed. We report here, for the first time, that indoxyl sulfate affects the thyroid gland mainly at the molecular level. The rabbit thyroid gland ex vivo system seems to be suitable for further studies on the thyroid gland in health and disease. However, the effect of TSH-TSHR signaling at ultrastructural, and epigenetic levels needs supplementary appraisal.

DOI: https://doi.org/10.26402/jpp.2023.6.10
Clin Chim Acta. 2024 Feb 09. pii: S0009-8981(24)00047-0. [Epub ahead of print]555 117806

The European biological variation study (EuBIVAS): Biological variation data for testosterone, follicle stimulating hormone, prolactin, luteinizing hormone and dehydroepiandrosterone sulfate in men.

Outi Itkonen, Niels Jonker, Aasne K Aarsand, Sverre Sandberg, Jorge Diaz-Garzon, Pilar Fernandez-Calle, Abdurrahman Coskun, William A Bartlett, Massimo Locatelli, Anna Carobene.

   BACKGROUND: Knowledge of biological variation (BV) of hormones is essential for interpretation of laboratory tests and for diagnostics of endocrinological and reproductive diseases. There is a lack of robust BV data for many hormones in men.
METHODS: We used serum samples collected weekly over 10 weeks from the European Biological Variation Study (EuBIVAS) to determine BV of testosterone, follicle-stimulating hormone (FSH), prolactin, luteinizing hormone (LH) and dehydroepiandrosterone sulfate (DHEA-S) in 38 men. We derived within-subject (CVI) and between-subject (CVG) BV estimates by CV-ANOVA after trend, outlier, and homogeneity analysis and calculated reference change values, index of individuality (II), and analytical performance specifications.
RESULTS: The CVI estimates were 10 % for testosterone, 8 % for FSH, 13 % for prolactin, 22 % for LH, and 9 % for DHEA-S, respectively. The IIs ranged between 0.14 for FSH to 0.66 for LH, indicating high individuality.
CONCLUSIONS: In this study, we have used samples from the highly powered EuBIVAS study to derive BV estimates for testosterone, FSH, prolactin, LH and DHEA-S in men. Our data confirm previously published BV estimates of testosterone, FSH and LH. For prolactin and DHEA-S BV data for men are reported for the first time.

Keywords:  Biological variation; Clinical interpretation; EuBIVAS; Hormones; Laboratory medicine; Reference change value

DOI:  https://doi.org/10.1016/j.cca.2024.117806
Ann Endocrinol (Paris). 2024 Feb 13. pii: S0003-4266(24)00033-7. [Epub ahead of print]

Is it useful to measure DHEAS levels in PCOS?

Hélène Boucher, Geoffroy Robin, Louise Ribière, Claire Martin, Stéphanie Espiard, Sophie Catteau Jonard.

   INTRODUCTION: A high prevalence of increased DHEAS (dehydroepiandrosterone sulfate) levels (about a third of cases)has been reported in women with polycystic ovary syndrome (PCOS). This excess of adrenal androgens remains a mystery in this ovarian pathology. It is well known that DHEAS production correlates negatively with age, and study populations of women with PCOS are generally young. To avoid this bias, a study was carried out on a large population of women with PCOS and control women, using normal DHEAS values for each age group, to better assess prevalence and better understand the link between PCOS and DHEAS.
METHODS: A retrospective cross-sectional study was conducted at the Lille University Hospital. A total of 1,223 patients with PCOS according to the Rotterdam criteria and 517 control women were included. DHEAS elevation was diagnosed according to the standards of the Lille University Hospital Institute of Biochemistry and Molecular Biology, based on patient age. The prevalence of increased serum DHEAS levels was calculated in each population and according to PCOS phenotype. Correlations were assessed between serum DHEAS levels and clinical, hormonal, and metabolic markers, with adjustment for age.
RESULTS: Prevalence of increased DHEAS was significantly higher in the PCOS group than in the control group (8.1% vs. 4.3%; OR= 1.98 (95% CI: 1.23-3.19), p=0.005, and OR =1.07 (95% CI: 1.05-1.09), p= 0.014 without and with adjustment for BMI respectively), and in phenotypes A and C than in controls (OR= 2.88 (95% CI: 1.76 to 4.72), p<0.001 and OR= 2.81 (95% CI: 1.39 to 5.67), p=0.004 respectively), but not in phenotype D. A correlation was found between DHEAS level and total testosteronemia (r=0.34, p<0.001), androstenedione (r=0.24, p<0.001), 17 hydroxyprogesteronemia (r=0.22, p<0.001) and age (r=0.25, p<0.001). No correlations were found with AMH, LH or FSH, and a very weak positive correlation was found with BMI (r=0.15; p<0.001).
CONCLUSION: Using age-dependent norms, DHEAS elevation was found in only 8.1% of women with PCOS (11% in the case of phenotypes A and C) versus 4.3% in controls and women with phenotype D. DHEAS levels correlated only with other androgens, and not (or only minimally) with other ovarian, pituitary or metabolic markers. DHEAS assay therefore appears to be of no interest for positive diagnosis or understanding of the pathophysiology of PCOS, except in case of very high testosterone levels.

Keywords:  DHEAS; adrenal androgens; age; polycystic ovary syndrome

DOI:  https://doi.org/10.1016/j.ando.2024.01.011
Nat Chem Biol. 2024 Feb 12.

Host-microbiome orchestration of the sulfated metabolome.

Gabriel D D'Agostino, Snehal N Chaudhari, A Sloan Devlin.

Recent studies have demonstrated that metabolites produced by commensal bacteria causally influence health and disease. The sulfated metabolome is one class of molecules that has recently come to the forefront due to efforts to understand the role of these metabolites in host-microbiome interactions. Sulfated compounds have canonically been classified as waste products; however, studies have revealed a variety of physiological roles for these metabolites, including effects on host metabolism, immune response and neurological function. Moreover, recent research has revealed that commensal bacteria either chemically modify or synthesize a variety of sulfated compounds. In this Review, we explore how host-microbiome collaborative metabolism transforms the sulfated metabolome. We describe bacterial and mammalian enzymes that sulfonate and desulfate biologically relevant carbohydrates, amino acid derivatives and cholesterol-derived metabolites. We then discuss outstanding questions and future directions in the field, including potential roles of sulfated metabolites in disease detection, prevention and treatment. We hope that this Review inspires future research into sulfated compounds and their effects on physiology.

DOI: https://doi.org/10.1038/s41589-023-01526-9
J Virol. 2024 Feb 12. e0127823

Human induced pluripotent stem cells are resistant to human cytomegalovirus infection primarily at the attachment level due to the reduced expression of cell-surface heparan sulfate.

Hideya Kawasaki, Takahiko Hariyama, Isao Kosugi, Shiori Meguro, Futoshi Iwata, Kosuke Shimizu, Yasuhiro Magata, Toshihide Iwashita.

  Cytomegalovirus (CMV), a type of herpes virus, is the predominant cause of congenital anomalies due to intrauterine infections in humans. Adverse outcomes related to intrauterine infections with human cytomegalovirus (HCMV) vary widely, depending on factors such as fetal infection timing, infection route, and viral virulence. The precise mechanism underlying HCMV susceptibility remains unclear. In this study, we compared the susceptibility of neonatal human dermal fibroblast cells (NHDFCs) and human induced pluripotent stem cells (hiPSCs) derived from NHDFCs, which are genetically identical to HCMV, using immunostaining, microarray, in situ hybridization, quantitative PCR, and scanning electron microscopy. These cells were previously used to compare CMV susceptibility, but the underlying mechanisms were not fully elucidated. HCMV susceptibility of hiPSCs was significantly lower in the earliest phase. No shared gene ontologies were observed immediately post-infection between the two cell types using microarray analysis. Early-stage expression of HCMV antigens and the HCMV genome was minimal in immunostaining and in in situ hybridization in hiPSCs. This strongly suggests that HCMV does not readily bind to hiPSC surfaces. Scanning electron microscopy performed using the NanoSuit method confirmed the scarcity of HCMV particles on hiPSC surfaces. The zeta potential and charge mapping of the charged surface in NHDFCs and hiPSCs exhibited minimal differences when assessed using zeta potential analyzer and scanning ion conductance microscopy; however, the expression of heparan sulfate (HS) was significantly lower in hiPSCs compared with that in NHDFCs. Thus, HS expression could be a primary determinant of HCMV resistance in hiPSCs at the attachment level.IMPORTANCENumerous factors such as attachment, virus particle entry, transcription, and virus particle egress can affect viral susceptibility. Since 1984, pluripotent cells are known to be CMV resistant; however, the exact mechanism underlying this resistance remains elusive. Some researchers suggest inhibition in the initial phase of HCMV binding, while others have suggested the possibility of a sufficient amount of HCMV entering the cells to establish latency. This study demonstrates that HCMV particles rarely attach to the surfaces of hiPSCs. This is not due to limitations in the electrostatic interactions between the surface of hiPSCs and HCMV particles, but due to HS expression. Therefore, HS expression should be recognized as a key factor in determining the susceptibility of HCMV in congenital infection in vitro and in vivo. In the future, drugs targeting HS may become crucial for the treatment of congenital CMV infections. Thus, further research in this area is warranted.

Keywords:  cytomegalovirus; heparan sulfate; iPS cells

DOI:  https://doi.org/10.1128/jvi.01278-23
bioRxiv. 2024 Feb 03. pii: 2024.02.03.578714. [Epub ahead of print]

The co-receptor Tspan12 directly captures Norrin to promote ligand-specific β-catenin signaling.

Elise S Bruguera, Jacob P Mahoney, William I Weis.

Wnt/ β -catenin signaling directs animal development and tissue renewal in a tightly controlled, cell- and tissue-specific manner. In the central nervous system, the atypical ligand Norrin controls angiogenesis and maintenance of the blood-brain barrier and blood-retina barrier through the Wnt/ β -catenin pathway. Like Wnt, Norrin activates signaling by binding and heterodimerizing the receptors Frizzled (Fzd) and Low-density lipoprotein receptor-related protein 5 or 6 (LRP5/6), leading to membrane recruitment of the intracellular transducer Dishevelled (Dvl); this ultimately results in the stabilization of the transcriptional coactivator β -catenin. Unlike Wnt, the cysteine-knot ligand Norrin only signals through Fzd4 and additionally requires the co-receptor Tspan12; however, the mechanism underlying Tspan12-mediated signal enhancement is unclear. It has been proposed that Tspan12 integrates into the Norrin-Fzd4 complex to enhance Norrin-Fzd4 affinity or otherwise allosterically modulate Fzd4 signaling. Here, we measure direct, high-affinity binding between purified Norrin and Tspan12 in a lipid environment and use AlphaFold models to interrogate this interaction interface. We find that Tspan12 and Fzd4 can simultaneously bind Norrin and that a pre-formed Tspan12/Fzd4 heterodimer, as well as cells co-expressing Tspan12 and Fzd4, more efficiently capture low concentrations of Norrin than Fzd4 alone. We also show that Tspan12 competes with both heparan sulfate proteoglycans and LRP6 for Norrin binding and that Tspan12 does not impact Fzd4-Dvl affinity in the presence or absence of Norrin. Our findings suggest that Tspan12 does not allosterically enhance Fzd4 binding to Norrin or Dvl, but instead functions to directly capture Norrin upstream of signaling.

DOI: https://doi.org/10.1101/2024.02.03.578714
bioRxiv. 2024 Feb 03. pii: 2024.02.02.578681. [Epub ahead of print]

Tyrosine-sulfated peptide hormone induces flavonol biosynthesis to control elongation and differentiation in Arabidopsis primary root.

Maria Florencia Ercoli, Alexandra M Shigenaga, Artur Teixeira de Araujo, Rashmi Jain, Pamela C Ronald.

In Arabidopsis roots, growth initiation and cessation are organized into distinct zones. How regulatory mechanisms are integrated to coordinate these processes and maintain proper growth progression over time is not well understood. Here, we demonstrate that the peptide hormone PLANT PEPTIDE CONTAINING SULFATED TYROSINE 1 (PSY1) promotes root growth by controlling cell elongation. Higher levels of PSY1 lead to longer differentiated cells with a shootward displacement of characteristics common to mature cells. PSY1 activates genes involved in the biosynthesis of flavonols, a group of plant-specific secondary metabolites. Using genetic and chemical approaches, we show that flavonols are required for PSY1 function. Flavonol accumulation downstream of PSY1 occurs in the differentiation zone, where PSY1 also reduces auxin and reactive oxygen species (ROS) activity. These findings support a model where PSY1 signals the developmental-specific accumulation of secondary metabolites to regulate the extent of cell elongation and the overall progression to maturation. Teaser PSY1-induced flavonol biosynthesis in Arabidopsis roots modulates the distance from the root tip at which cell elongation ceases.

DOI: https://doi.org/10.1101/2024.02.02.578681
Int J Biol Macromol. 2024 Feb 11. pii: S0141-8130(24)00931-0. [Epub ahead of print] 130128

Sulfation of hyaluronic acid reconfigures the mechanistic pathway of bone morphogenetic protein-2 aggregation.

Devi Prasanna Behera, Suchismita Subadini, Uwe Freudenberg, Harekrushna Sahoo.

  Bone morphogenetic protein-2 (BMP-2) is a critical growth factor of bone extracellular matrix (ECM), pivotal for osteogenesis. Glycosaminoglycans (GAGs), another vital ECM biomolecules, interact with growth factors, affecting signal transduction. Our study primarily focused on hyaluronic acid (HA), a prevalent GAG, and its sulfated derivative (SHA). We explored their impact on BMP-2's conformation, aggregation, and mechanistic pathways of aggregation using diverse optical and rheological methods. In the presence of HA and SHA, the secondary structure of BMP-2 underwent a structured transformation, characterized by a substantial increase in beta sheet content, and a detrimental alteration, manifesting as a shift towards unstructured content, respectively. Although both HA and SHA induced BMP-2 aggregation, their mechanisms differed. SHA led to rapid amorphous aggregates, while HA promoted amyloid fibrils with a lag phase and sigmoidal kinetics. Aggregate size and shape varied; HA produced larger structures, SHA smaller. Each aggregation type followed distinct pathways influenced by viscosity and excluded volume. Higher viscosity, low diffusivity of protein and higher excluded volume In the presence of HA promotes fibrillation having size in micrometer range. Low viscosity, high diffusivity of protein and lesser excluded volume leads to amorphous aggregate of size in nanometer range.

Keywords:  Amorphous aggregate; Amyloid fibril; Glycosaminoglycan

DOI:  https://doi.org/10.1016/j.ijbiomac.2024.130128
Cureus. 2024 Jan;16(1): e52094

Heparin-Induced Thrombocytopenia: A Case Report Four Years After the Initiation of Maintenance Hemodialysis.

Junichiro Nishiyama, Keishi Higashi.

  Heparin-induced thrombocytopenia type II (HIT) is a rare and serious complication of heparin exposure and is always a potential risk in hemodialysis patients who routinely receive heparin. It is particularly likely to occur during the induction phase of dialysis. However, it is known to be less prevalent in long-term maintenance dialysis. In the present study, we experienced a maintenance dialysis patient who developed HIT four years after starting dialysis. After careful diagnosis with antibodies assay and clinical scores, the patient was treated with immediate heparin interruption, argatroban administration followed by nafamostat, and simple plasma exchange, which resulted in remission. Therefore, even in the maintenance phase of hemodialysis, it is important to consider HIT in the differential diagnosis of thrombocytopenia.

Keywords:  argatroban; disseminated intravascular coagulation (dic); hemodialysis; heparin; heparin induced thrombocytopenia; hit antibody; low molecular weight heparin (lmwh); maintenance hemodialysis; plasma exchange; thrombocytopenia

DOI:  https://doi.org/10.7759/cureus.52094
Int J Cancer. 2024 Feb 15.

Circulating endogenous sex steroids and risk of differentiated thyroid carcinoma in men and women.

Sabina Rinaldi, Laure Dossus, Pekka Keski-Rahkonen, Agneta Kiss, Anne-Sophie Navionis, Carine Biessy, Ruth Travis, Elisabete Weiderpass, Isabelle Romieu, Anne Kirstine Eriksen, Anne Tjonneland, Marina Kvaskoff, Marianne Canonico, Thérèse Truong, Verena Katzke, Rudolf Kaaks, Alberto Catalano, Salvatore Panico, Giovanna Masala, Rosario Tumino, Marko Lukic, Karina Standahl Olsen, Raul Zamora-Ros, Carmen Santiuste, Amaia Aizpurua Atxega, Marcela Guevara, Miguel Rodriguez-Barranco, Maria Sandstrom, Joakim Hennings, Martin Almquist, Elom Aglago Kouassivi, Sofia Christakoudi, Marc Gunter, Silvia Franceschi.

  Thyroid cancer (TC) is substantially more common in women than in men, pointing to a possible role of sex steroid hormones. We investigated the association between circulating sex steroid hormones, sex hormone binding globulin (SHBG) and the risk of differentiated TC in men and women within the European Prospective Investigation into Cancer and nutrition (EPIC) cohort. During follow-up, we identified 333 first primary incident cases of differentiated TC (152 in pre/peri-menopausal women, 111 in post-menopausal women, and 70 in men) and 706 cancer-free controls. Women taking exogenous hormones at blood donation were excluded. Plasma concentrations of testosterone, androstenedione, dehydroepiandrosterone, estradiol, estrone and progesterone (in pre-menopausal women only) were performed using liquid chromatography/mass spectrometry method. SHBG concentrations were measured by immunoassay. Odds ratios (ORs) were estimated using conditional logistic regression models adjusted for possible confounders. No significant associations were observed in men and postmenopausal women, while a borderline significant increase in differentiated TC risk was observed with increasing testosterone (adjusted OR T3 vs T1: 1.68, 95% CI: 0.96-2.92, ptrend = .06) and androstenedione concentrations in pre/perimenopausal women (adjusted OR T3 vs T1: 1.78, 95% CI: 0.96-3.30, ptrend = .06, respectively). A borderline decrease in risk was observed for the highest progesterone/estradiol ratio (adjusted OR T3 vs T1: 0.54, 95% CI: 0.28-1.05, ptrend = .07). Overall, our results do not support a major role of circulating sex steroids in the etiology of differentiated TC in post-menopausal women and men but may suggest an involvement of altered sex steroid production in pre-menopausal women.

Keywords:  differentiated thyroid cancer; prospective study; sex steroids

DOI:  https://doi.org/10.1002/ijc.34872