bims-supasi Biomed News
on Sulfation pathways and signalling
Issue of 2022‒07‒10
twenty papers selected by
Jonathan Wolf Mueller
University of Birmingham

  1. Int J Mol Sci. 2022 Jul 05. pii: 7485. [Epub ahead of print]23(13):
      The crucial roles of dermatan sulfate (DS) have been demonstrated in tissue development of the cutis, blood vessels, and bone through construction of the extracellular matrix and cell signaling. Although DS classically exerts physiological functions via interaction with collagens, growth factors, and heparin cofactor-II, new functions have been revealed through analyses of human genetic disorders as well as of knockout mice with loss of DS-synthesizing enzymes. Mutations in human genes encoding the epimerase and sulfotransferase responsible for the biosynthesis of DS chains cause connective tissue disorders including spondylodysplastic type Ehlers-Danlos syndrome, characterized by skin hyperextensibility, joint hypermobility, and tissue fragility. DS-deficient mice show perinatal lethality, skin fragility, vascular abnormalities, thoracic kyphosis, myopathy-related phenotypes, acceleration of nerve regeneration, and impairments in self-renewal and proliferation of neural stem cells. These findings suggest that DS is essential for tissue development in addition to the assembly of collagen fibrils in the skin, and that DS-deficient knockout mice can be utilized as models of human genetic disorders that involve impairment of DS biosynthesis. This review highlights a novel role of DS in tissue development studies from the past decade.
    Keywords:  Ehlers–Danlos syndrome; biglycan; carbohydrate sulfotransferase 14; chondroitin sulfate; decorin; dermatan 4-O-sulfotransferase; dermatan sulfate; dermatan sulfate epimerase; glycosaminoglycan; proteoglycan
  2. JOR Spine. 2022 Jun;5(2): e1209
      Background: Daily physiologic loading causes fluctuations in hydration of the intervertebral disc (IVD); thus, the embedded cells experience cyclic alterations to their osmotic environment. These osmotic fluctuations have been described as a mechanism linking mechanics and biology, and have previously been shown to promote biosynthesis in chondrocytes. However, this phenomenon has yet to be fully interrogated in the IVD. Additionally, the specialized extracellular matrix surrounding the cells, the pericellular matrix (PCM), transduces the biophysical signals that cells ultimately experience. While it is known that the PCM is altered in disc degeneration, whether it disrupts normal osmotic mechanotransduction has yet to be determined. Thus, our objectives were to assess: (1) whether dynamic osmotic conditions stimulate biosynthesis in nucleus pulposus cells, and (2) whether pericellular heparan sulfate proteoglycans (HSPGs) modulate the biosynthetic response to osmotic loading.Methods: Bovine nucleus pulposus cells isolated with retained PCM were encapsulated in 1.5% alginate beads and treated with or without heparinase III, an enzyme that degrades the pericellular HSPGs. Beads were subjected to 1 h of daily iso-osmotic, hyper-osmotic, or hypo-osmotic loading for 1, 2, or 4 weeks. At each timepoint the total amount of extracellular and pericellular sGAG/DNA were quantified. Additionally, whether osmotic loading triggered alterations to HSPG sulfation was assessed via immunohistochemistry for the heparan sulfate 6-O-sulfertransferase 1 (HS6ST1) enzyme.
    Results: Osmotic loading significantly influenced sGAG/DNA accumulation with a hyper-osmotic change promoting the greatest sGAG/DNA accumulation in the pericellular region compared with iso-osmotic conditions. Heparanase-III treatment significantly reduced extracellular sGAG/DNA but pericellular sGAG was not affected. HS6ST1 expression was not affected by osmotic loading.
    Conclusion: Results suggest that hyper-osmotic loading promotes matrix synthesis and that modifications to HSPGs directly influence the metabolic responses of cells to osmotic fluctuations. Collectively, results suggest degeneration-associated modifications to pericellular HSPGs may contribute to the altered mechanobiology observed in disease.
    Keywords:  heparan sulfate proteoglycan; intervertebral disc; mechanotransduction; nucleus pulposus; osmotic; pericellular matrix
  3. Br J Pharmacol. 2022 Jul 07.
      BACKGROUND AND PURPOSE: Chondroitin sulfate proteoglycan (CSPG) constitutes the neurogenic niche in the hippocampus. The reduction of hippocampal neurogenesis is involved in aging-related cognitive decline and dementia. The purpose of this study is to find candidates that improve cognitive function by analyzing the effects of memantine (MEM), a therapeutic agent for Alzheimer's disease, on CSPG and adult hippocampal neurogenesis.EXPERIMENTAL APPROACH: The effects of MEM on neurogenesis-related cells and CSPG content were assessed in the hippocampus of middle-aged mice. The MEM-induced alterations in gene expressions of neurotrophins and enzymes associated with biosynthesis and degradation of CSPG in the hippocampus were also measured. The effects of MEM on cognitive function were estimated using a behavioral test battery. The same set of behavioral tests was applied to evaluate the effects of pharmacological depletion of CSPG in the hippocampus.
    KEY RESULTS: The densities of newborn granule cells and content of CSPG in the hippocampus were increased by MEM. The expression levels of the enzyme responsible for the biosynthesis CSPG were increased by MEM. The neurotrophin-related molecules were activated by MEM. Short- and long-term memory performance was improved by MEM. Pharmacological depletion of CSPG impairs the effects of MEM on cognitive improvement in middle-aged mice.
    CONCLUSIONS AND IMPLICATIONS: MEM regulates the biosynthesis and degradation of CSPG, which may underlie the improvement of cognitive function via the promotion of adult hippocampal neurogenesis. These results imply that CSPG-related enzymes may be potentially attractive candidates for the treatment of aging-related cognitive decline.
    Keywords:  adult neurogenesis; chondroitin sulfate proteoglycan; cognitive function; hippocampus; memantine
  4. Glycobiology. 2022 Jul 05. pii: cwac042. [Epub ahead of print]
      The COVID-19 pandemic has steered the global therapeutic research efforts towards the discovery of potential anti-SARS-CoV-2 molecules. The role of the viral spike glycoprotein (S-protein) has been clearly established in SARS-CoV-2 infection through its capacity to bind to the host cell surface heparan sulfate proteoglycan (HSPG) and angiotensin-converting enzyme-2 (ACE2). The antiviral strategies targeting these two virus receptors are currently under intense investigation. However, the rapid evolution of the SARS-CoV-2 genome has resulted in numerous mutations in the S-protein posing a significant challenge for the design of S-protein-targeted inhibitors. As an example, the two key mutations in the S-protein receptor-binding domain (RBD), L452R, and T478K in the SARS-CoV-2 Delta variant (B.1.617.2) confer tighter binding to the host epithelial cells. Marine sulfated glycans (MSGs) demonstrate excellent inhibitory activity against SARS-CoV-2 via competitive disruption of the S-protein RBD-HSPG interactions and thus have the potential to be developed into effective prophylactic and therapeutic molecules. In this study, seven different MSGs were evaluated for their anti-SARS-CoV-2 activity in a virus entry assay utilizing a SARS-CoV-2 pseudovirus coated with S-protein of the wild-type (Wuhan-Hu-1) or the Delta (B.1.617.2) strain. Although all tested MSGs showed strong inhibitory activity against both strains, no correlations between MSG structural features and virus inhibition could be drawn. Nevertheless, the current study provides evidence for the maintenance of inhibitory activity of MSGs against evolving SARS-CoV-2 strains.
    Keywords:  Fucosylated chondroitin sulfate; Nuclear magnetic resonance; SARS-CoV-2; Sulfated fucan; Viral inhibition
  5. Front Endocrinol (Lausanne). 2022 ;13 915494
      Background: The associations of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) with diabetic kidney disease (DKD) remained unclear. Thus, this cross-sectional study aimed to explore the associations of DHEA and DHEAS with the risk of DKD in patients with T2DM.Methods: The information of 1251 patients with T2DM were included in this study. Serum DHEA and DHEAS were quantified using liquid chromatography-tandem mass spectrometry assays. Multivariate logistic regression analyses were used to assess the associations of DHEA and DHEAS with DKD as well as high urine albumin to creatinine ratio (ACR).
    Results: In men with T2DM, the risk of DKD decreased with an increasing DHEA concentration after adjustment for traditional risk factors; the fully adjusted OR (95% CI) for tertile3 vs tertile1 was 0.37 (0.19-0.70; P = 0.010 for trend). Similarly, when taking high ACR as the outcome, low DHEA levels were still significantly associated with increased odds of high ACR (OR, 0.37; 95% CI, 0.19-0.72 for tertile3 vs tertile1; P = 0.012 for trend). The restricted cubic spline showed that the risk of DKD gradually decreased with the increment of serum DHEA levels (P-overall = 0.007; P-nonlinear = 0.161). DHEAS was not independently associated with the risk of DKD in men. In contrast, no significant relationships were found between DHEA and DHEAS and the risk of DKD in women (all P > 0.05).
    Conclusions: In men with T2DM, low serum DHEA levels were independently related to the risk of DKD after adjustment for traditional risk factors. Our finding highlights the potential role of DHEA in the development of DKD in men with T2DM.
    Keywords:  androgen; dehydroepiandrosterone; dehydroepiandrosterone sulfate; diabetic kidney disease; type 2 diabetes mellitus
  6. J Agric Food Chem. 2022 Jul 05.
      Epigallocatechin-3-gallate (EGCG), a major green tea polyphenol, has beneficial effects on human health. This study aimed to elucidate the detailed EGCG sulfation process to better understand its phase II metabolism, a process required to maximize its health benefits. Results show that kinetic activity of sulfation in the human liver and intestinal cytosol is 2-fold and 60- to 300-fold higher than that of methylation and glucuronidation, respectively, suggesting sulfation as the key metabolic pathway. Moreover, SULT1A1 and SULT1A3 are responsible for sulfation in the liver and intestine, respectively. Additionally, our human ingestion study revealed that the concentration of EGCG-4″-sulfate in human plasma (Cmax: 177.9 nmol·L-1, AUC: 715.2 nmol·h·L-1) is equivalent to free EGCG (Cmax: 233.5 nmol·L-1, AUC: 664.1 nmol·h·L-1), suggesting that EGCG-4″-sulfate is the key metabolite. These findings indicate that sulfation is a crucial factor for improving EGCG bioavailability, while also advancing the understanding of the bioactivity and toxicity of EGCG.
    Keywords:  bioavailability; epigallocatechin-3-gallate; metabolism; pharmacokinetics; sulfation
  7. Carbohydr Polym. 2022 Oct 01. pii: S0144-8617(22)00639-7. [Epub ahead of print]293 119734
      Mucopolysaccharidoses (MPS) are a group of rare lysosomal storage diseases characterized by glycosaminoglycan (GAG) accumulation causing progressive multi-organs dysfunction and ultimately severe cardio-respiratory damages. Human cystatin C (hCC), a potent inhibitor of cysteine cathepsins, plays an important role in respiratory diseases. However, its regulation remained unknown in MPS. Herein, elevated hCC levels were measured in respiratory specimens from MPS-I, -II, and -III patients and were significantly correlated with severe respiratory symptoms (rs = 0.7173). Heparan sulfate (HS), a prominent GAG, dampened its inhibitory activity toward cathepsin L in a dose-dependent manner. HS and HS-oligosaccharides bound tightly hCC, in combination with a secondary structure rearrangement. Molecular modeling studies identified three HS binding regions in hCC, including the N-terminus, which is crucial in the inhibition of cathepsins. Impairment of inhibitory potential of hCC may reflect abnormal regulation of proteolytic activity of cathepsin L in lung, ultimately contributing to the severity of MPS.
    Keywords:  Glycosaminoglycan; Inhibitor; Lung; Molecular dynamic; Protease
  8. J Am Soc Mass Spectrom. 2022 Jul 06. 33(7): 1276-1281
      The identification and confirmation of steroid sulfate metabolites in biological samples are essential to various fields, including anti-doping analysis and clinical sciences. Ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) is the leading method for the detection of intact steroid conjugates in biofluids, but because of the inherent complexity of biological samples and the low concentration of many targets of interest, metabolite identification based solely on mass spectrometry remains a major challenge. The confirmation of new metabolites typically depends on a comparison with synthetically derived reference materials that encompass a range of possible conjugation sites and stereochemistries. Herein, energy-resolved collision-induced dissociation (CID) is used as part of UHPLC-HRMS/MS analysis to distinguish between regio- and stereo-isomeric steroid sulfate compounds. This wholly MS-based approach was employed to guide the synthesis of reference materials to unambiguously confirm the identity of an equine steroid sulfate biomarker of testosterone propionate administration.
  9. Hormones (Athens). 2022 Jul 08.
      PURPOSE: Dehydroepiandrosterone sulfate (DHEAS) is observed to be decreased in sepsis and inflammatory conditions. In the present study, we assessed the levels of DHEAS and cortisol and the DHEAS/cortisol ratio and their association with inflammatory markers in patients with COVID-19.METHODS: The study recruited 76 RT-PCR-positive COVID-19-positive patients and 79 healthy controls. The blood samples were collected and were analyzed for cortisol and DHEAS.
    RESULTS: We observed decreased levels of DHEAS and DHEAS/cortisol ratio and increased levels of cortisol in cases when compared with controls. DHEAS and DHEAS/cortisol ratio showed a decreasing trend with the increase in disease severity.
    CONCLUSION: The present study is the first of its kind comparing DHEAS levels and DHEAS/cortisol ratio in COVID-19 patients and control subjects. DHEAS, with its inhibitory effect on IL6 and activation of Tregs, may play a crucial role in immune defense mechanisms against COVID-19.
    Keywords:  COVID-19; Cortisol; DHEA; DHEAS
  10. Spine Surg Relat Res. 2022 ;6(3): 252-260
      Introduction: Chemonucleolysis with condoliase (chondroitin sulfate ABC endolyase) has been used to treat patients with lumbar disc herniation (LDH) in Japan since 2018. In this study, we retrospectively investigated clinical outcomes in patients who received an intradiscal condoliase injection for LDH and sought to identify significant predictors of good outcome.Methods: Indications for treatment were as follows: (1) unilateral leg pain with or without back pain, (2) nerve root compression caused by LDH confirmed on magnetic resonance imaging (MRI), and (3) leg pain resistant to at least 1 month of conservative treatment, including medication, nerve root block, or physical therapy. Patients with motor weakness or a history of severe allergy were excluded, as were those with the foraminal or sequestrated type of LDH. The injection was defined as effective if the numeric rating scale score for leg pain improved by ≥50% at 6 months post-treatment.
    Results: A total of 52 patients (mean age, 45.0 years) were enrolled and classified according to whether the injection was effective (E group, n=40, 76.9%) or less effective (L group, n=9, 17.3%). Three patients (5.8%) underwent herniotomy for residual pain within 6 months of the injection. There were no severe adverse events. Reduction of herniation was seen on MRI more often in the E group than in the L group. The effectiveness in patients with transligamentous LDH was similar to that in patients with subligamentous LDH. High-intensity signal change in the area of LDH on pretreatment T2-weighted MRI was a significant predictor of successful leg pain relief.
    Conclusions: An intradiscal condoliase injection was a safe and effective treatment for painful radiculopathy caused by LDH. Leg pain was more likely to improve in patients with high-intensity signal change in the area of LDH before treatment.
    Keywords:  Intradical injection; chemonucleolysis; condoliase; high-intensity signal change; leg pain; low back pain; lumbar intervertebral disc herniation; radiculopathy
  11. Cell Death Dis. 2022 Jul 07. 13(7): 586
      Herein, we describe the clinical and hematological features of three genetically related families predisposed to myeloproliferative neoplasms (MPNs). Using whole-exome sequencing, we identified a c.1367delG mutation(p.Arg456fs) in CHST15 (NM_001270764), a gene encoding a type II transmembraneglycoproteinthat acts as a sulfotransferase and participates in the biosynthesis of chondroitin sulfate E, in germline and somatic cells in familial MPN. CHST15defects caused an increased JAK2V617F allele burden and upregulated p-Stat3 activity,leading to an increase in the proliferative and prodifferentiation potential of transgenic HEL cells. We demonstrated that mutant CHST15 is able to coimmmunoprecipitate the JAK2 protein,suggesting the presence of a CHST15-JAK2-Stat3 signaling axis in familial MPN. Gene expression profiling showed that the FREM1, IFI27 and C4B_2 genes are overexpressed in familial MPN, suggesting the activation of an "inflammatory response-extracellular matrix-immune regulation" signaling network in the CHST15 mutation background.We thus concluded that CHST15 is a novel gene that predisposes to familial MPN and increases the probability of disease development or transformation.
  12. Oncogene. 2022 Jul 07.
      Accumulating evidence identifies non-genetic mechanisms substantially contributing to drug resistance in cancer patients. Preclinical and clinical data implicate the transcriptional co-activators YAP1 and its paralog TAZ in resistance to multiple targeted therapies, highlighting the strong need for therapeutic strategies overcoming YAP1/TAZ-mediated resistance across tumor entities. Here, we show particularly high YAP1/TAZ activity in MITFlow/AXLhigh melanomas characterized by resistance to MAPK pathway inhibition and broad receptor tyrosine kinase activity. To uncover genetic dependencies of melanoma cells with high YAP1/TAZ activity, we used a genome-wide CRISPR/Cas9 functional screen and identified SLC35B2, the 3'-phosphoadenosine-5'-phosphosulfate transporter of the Golgi apparatus, as an essential gene for YAP1/TAZ-driven drug resistance. SLC35B2 expression correlates with tumor progression, and its loss decreases heparan sulfate expression, reduces receptor tyrosine kinase activity, and sensitizes resistant melanoma cells to BRAF inhibition in vitro and in vivo. Thus, targeting heparan sulfation via SLC35B2 represents a novel approach for breaking receptor tyrosine kinase-mediated resistance to MAPK pathway inhibitors.
  13. Life Sci Alliance. 2022 Nov;pii: e202201366. [Epub ahead of print]5(11):
      Parkinson's disease (PD) is a debilitating neurodegenerative disorder characterized by progressive motor decline and the aggregation of α-synuclein protein. Growing evidence suggests that α-synuclein aggregates may spread from neurons of the digestive tract to the central nervous system in a prion-like manner, yet the mechanisms of α-synuclein transmission and neurotoxicity remain poorly understood. Animal models that are amenable to high-throughput investigations are needed to facilitate the discovery of disease mechanisms. Here we describe the first Caenorhabditis elegans models in which feeding with α-synuclein preformed fibrils (PFFs) induces dopaminergic neurodegeneration, prion-like seeding of aggregation of human α-synuclein expressed in the host, and an associated motor decline. RNAi-mediated knockdown of the C. elegans syndecan sdn-1, or other enzymes involved in heparan sulfate proteoglycan synthesis, protected against PFF-induced α-synuclein aggregation, motor dysfunction, and dopamine neuron degeneration. This work offers new models by which to investigate gut-derived α-synuclein spreading and propagation of disease.
  14. Mar Biotechnol (NY). 2022 Jul 07.
      Excessive osteoclast differentiation and/or bone resorptive function causes a gradual loss of bone, leading to the pathogenesis of bone diseases such as osteoporosis (OP). In this study, a sulfated glucuronorhamnoxylan polysaccharide (designated SPS-CF) of the green alga Capsosiphon fulvescens was evaluated for anti-osteoporotic activity using osteoclastic cells differentiated from RAW264.7 macrophages by receptor activator of NF-κB ligand (RANKL) treatment and ovariectomized (OVX) female mice as a postmenopausal OP model. With negligible cytotoxicity, SPS-CF (50 μg/mL) significantly suppressed tartrate-resistant acid phosphatase (TRAP) activity, actin ring formation, and expression of matrix metalloproteinase 9 (MMP-9), cathepsin K, TRAF6, p-Pyk2, c-Cbl, c-Src, gelsolin, carbonic anhydrase II (CA II), and integrin β3, indicating that SPS-CF inhibits the differentiation and bone resorptive function of osteoclasts. Removal of sulfate groups from SPS-CF abolished its anti-osteoclastogenic activities, demonstrating that sulfate groups are critical for its activity. Oral administration of SPS-CF (400 mg/kg/day) to OVX mice significantly augmented the bone mineral density (BMD) and serum osteoprotegerin (OPG)/RANKL ratio. These results demonstrated that SPS-CF exerts significant anti-osteoporotic activity by dampening osteoclastogenesis and bone resorption via downregulation of TRAF6-c-Src-Pyk2-c-Cbl-gelsolin signaling and augmentation of serum OPG/RANKL ratios in OVX mice, suggesting that SPS-CF can be a novel anti-osteoporotic compound for treating postmenopausal OP.
    Keywords:  Anti-osteoporosis; Capsosiphon fulvescens; Sulfated polysaccharide; Ulvan polysaccharide
  15. Phytomedicine. 2022 Jun 19. pii: S0944-7113(22)00367-1. [Epub ahead of print]104 154288
      BACKGROUND: Berberine has been shown in clinical studies to have many health benefits, including anti-inflammatory and antioxidant properties, along with gut-flora balancing properties. However, its clinical efficacy is hindered by its low oral bioavailability and rapid metabolism.PURPOSE: This study aims to identify the berberine metabolites' forms and characterize their biodistribution patterns in and out of HepG2 cells.
    METHODS: The qualitative analysis of metabolites of berberine in HepG2 cells was performed using the LC/MSn-IT-TOF method. Subsequent cellular pharmacokinetics characterization of intracellular and extracellular berberine and its metabolites was performed by LC-MS/MS analysis.
    RESULTS: Berberine's metabolites of phase I metabolism were demethyleneberberine, jatrorrhizine, columbamine, berberrubine, etc., while its phase II metabolites were sulfate and glucuronide conjugates of phase I metabolites. Among the phase I metabolites of berberine, jatrorrhizine+columbamine accounted for over two-thirds of the total, followed by demethyleneberberine, which accounted for about a quarter. The intracellular demethyleneberberine is 25.14 times more enriched than extracellular demethyleneberberine. On the other hand, jatrorrhizine+columbamine and berberrubine were primarily distributed extracellularly, and their extracellular concentrations were 7.13 times and 15.61 times of their intracellular concentrations, respectively. Berberine metabolites produced in phase II metabolism are predominantly sulfate conjugates.
    CONCLUSION: Our results show that demethyleneberberine is highly concentrated intracellularly in HepG2, possibly because it is an essential metabolite of berberine that likely contributes to berberine's efficacy. In light of our findings, berberine's poor plasma concentration-effectiveness characteristics have been partially explained.
    Keywords:  Berberine; Cellular pharmacokinetics; Demethyleneberberine; Metabolites
  16. Cells. 2022 Jun 27. pii: 2033. [Epub ahead of print]11(13):
      Understanding changes in the expression of genes involved in regulating various components of the neural extracellular matrix (ECM) during aging can provide an insight into aging-associated decline in synaptic and cognitive functions. Hence, in this study, we compared the expression levels of ECM-related genes in the hippocampus of young, aged and very aged mice. ECM gene expression was downregulated, despite the accumulation of ECM proteoglycans during aging. The most robustly downregulated gene was carbohydrate sulfotransferase 3 (Chst3), the enzyme responsible for the chondroitin 6-sulfation (C6S) of proteoglycans. Further analysis of epigenetic mechanisms revealed a decrease in H3K4me3, three methyl groups at the lysine 4 on the histone H3 proteins, associated with the promoter region of the Chst3 gene, resulting in the downregulation of Chst3 expression in non-neuronal cells. Cluster analysis revealed that the expression of lecticans-substrates of CHST3-is tightly co-regulated with this enzyme. These changes in ECM-related genes were accompanied by an age-confounded decline in cognitive performance. Despite the co-directional impairment in cognitive function and average Chst3 expression in the studied age groups, at the individual level we found a negative correlation between mRNA levels of Chst3 and cognitive performance within the very aged group. An analysis of correlations between the expression of ECM-related genes and cognitive performance in novel object versus novel location recognition tasks revealed an apparent trade-off in the positive gene effects in one task at the expense of another. Further analysis revealed that, despite the reduction in the Chst3 mRNA, the expression of CHST3 protein is increased in glial cells but not in neurons, which, however, does not lead to changes in the absolute level of C6S and even results in the decrease in C6S in perineuronal, perisynaptic and periaxonal ECM relative to the elevated expression of its protein carrier versican.
    Keywords:  6-sulfation; aging; carbohydrate sulfotransferase 3; cognitive decline; epigenetic regulation; extracellular matrix
  17. Steroids. 2022 Jul 01. pii: S0039-128X(22)00115-5. [Epub ahead of print] 109077
      In epidemiological studies, blood levels of 17β-estradiol (E2) are associated with hormone-dependent diseases. The lack of specific methods impedes studies on the role of E2 metabolites and their conjugates in the etiology of hormone-dependent diseases. Stable-isotope dilution tandem mass spectrometry methods (coupled to gas chromatography and liquid chromatography systems) for the analysis of 22 endogenous estrogens, including both oxidative metabolites, as well as sulfates and glucuronides, was validated and the method applied to plasma of women with no breast cancer. No changes in estrogen profile during sample cleanup were observed and values for limit of detection (7fmol/ml - 2 pmol/ml), accuracies (80-122%) as well as intra- and inter-day precision (below 28%) at levels near the limit of quantification were acceptable. In human plasma only seven estrogens were detected and estrone conjugates contributed most to the estrogen profile.
    Keywords:  GC-MS/MS; LC-MS/MS; endogenous estrogens; human plasma; metabolism
  18. J Biol Chem. 2022 Jul 04. pii: S0021-9258(22)00674-3. [Epub ahead of print] 102232
      Tyrosine sulfation, a post-translational modification, can determine and often enhance protein-protein interaction specificity. Sulfotyrosyl residues (sTyr) are formed by the enzyme tyrosyl-protein sulfotransferase during protein maturation in the Golgi apparatus, and most often occur singly or as a cluster within a six-residue span. With both negative charge and aromatic character, sTyr facilitates numerous atomic contacts as visualized in binding interface structural models, thus there is no discernible binding site consensus. Found exclusively in secreted proteins, in this review we discuss the four broad sequence contexts in which sTyr has been observed: first, a solitary sTyr residue has been shown to be critical for diverse high-affinity interactions, such as between peptide hormones and their receptors, in both plants and animals. Second, sTyr clusters within structurally flexible anionic segments are essential for a variety of cellular processes, including coreceptor binding to the HIV-1 envelope spike protein during virus entry, chemokine interactions with receptors, and leukocyte rolling cell adhesion. Third, a subcategory of sTyr clusters are found in conserved acidic sequences termed hirudin-like motifs that enable proteins to interact with thrombin; consequently, many proven and potential therapeutic proteins derived from blood-consuming invertebrates depend on sTyr residues for their activity. Finally, several proteins that interact with collagen or similar proteins contain one or more sTyr residues within an acidic residue array. Refined methods to direct sTyr incorporation in peptides synthesized both in vitro and in vivo, together with continued advances in MS and affinity detection, promise to accelerate discoveries of sTyr occurrence and function.
    Keywords:  C‐C chemokine receptor type 5 (CCR5); cytokine; follicle‐stimulating hormone (FSH); leucine‐rich repeat (LRR); peptide hormone; plant hormone; post‐translational modification (PTM); protein‐protein interaction; thrombin; tyrosine sulfation
  19. Front Immunol. 2022 ;13 903526
      Endogenous indole and its derivatives (indoles), considered as promising N-substituted heterocyclic compounds, are tryptophan metabolites derived from intestinal microbiota and exhibit a range of biological activities. Recent studies indicate that indoles contribute to maintaining the biological barrier of the human intestine, which exert the anti-inflammatory activities mainly through activating AhR and PXR receptors to affect the immune system's function, significantly improving intestinal health (inflammatory bowel disease, hemorrhagic colitis, colorectal cancer) and further promote human health (diabetes mellitus, central system inflammation, and vascular regulation). However, the revealed toxic influences cannot be ignored. Indoxyl sulfate, an indole derivative, performs nephrotoxicity and cardiovascular toxicity. We addressed the interaction between indoles and intestinal microbiota and the indoles' effects on human health as double-edged swords. This review provides scientific bases for the correlation of indoles with diseases moreover highlights several directions for subsequent indoles-related studies.
    Keywords:  dual role; indole; indoxyl sulfate; inflammation; intestinal flora
  20. J Allergy Clin Immunol Pract. 2022 Jul 01. pii: S2213-2198(22)00653-5. [Epub ahead of print]
      BACKGROUND: Heparin allergy most frequently manifests as delayed-type hypersensitivity (DTH) causing an itchy inflammatory skin reaction at the site of subcutaneous injection. An important differential diagnosis is circumscribed skin necrosis due to heparin-induced thrombocytopenia.OBJECTIVES: An inflammatory skin reaction to subcutaneously injected heparin generally entails the quest for alternative anticoagulation; concerns may particularly arise in an emergency situation requiring intravenous heparin administration.
    METHODS: All heparin DTH cases seen in our department over the last 17 years underwent standardized allergy diagnostics including challenge testing, i.e. subcutaneous injection of fondaparinux and intravenous administration of unfractionated heparin (UFH).
    RESULTS: Of a total of 50 patients with confirmed heparin allergy, DTH was found in 48 (96.0%), immediate-type, presumably IgE-mediated hypersensitivity was diagnosed in only two (4.0%). In the 48 DTH cases, intradermal testing revealed broad cross-reactivity between UFH and low molecular-weight heparins (LMWH) including nadroparin, dalteparin, and enoxaparin. Cross-reactivity with (or concomitant sensitization to) fondaparinux was seen in only 3 (6.3%) cases. Intravenous administration of UFH was tolerated by all 45 patients challenged, despite DTH to UFH and LMWH as demonstrated by intradermal testing.
    CONCLUSIONS: If an inflammatory skin reaction at the site of subcutaneously injected heparin is observed or reported without any evidence of skin necrosis or thrombocytopenia, intravenous administration of UFH seems to be sufficiently safe and may be considered without allergy testing if urgently indicated in an emergency situation. Fondaparinux is the most suitable alternative for subcutaneous application.
    Keywords:  anaphylaxis; drug adverse reaction; drug allergy; drug hypersensitivity; eczema; exanthema; fondaparinux; low molecular-weight heparin; unfractionated heparin