bims-supasi 2022-09-04 papers

bims-supasi

Biomed News

on Sulfation pathways and signalling

Issue of 2022–09–04
sixteen papers selected by
Jonathan Wolf Mueller, University of Birmingham

Comprehensive structural assignment of glycosaminoglycan oligo- and polysaccharides by protein nanopore.
Interactions between heparin and SARS-CoV-2 spike glycoprotein RBD from omicron and other variants.
Chondroitin sulfate modified chitosan nanoparticles as an efficient and targeted gene delivery vehicle to chondrocytes.
Sensory Nerve Maintains Intervertebral Disc Extracellular Matrix Homeostasis Via CGRP/CHSY1 Axis.
Differential dependency of human glioblastoma cells on vascular endothelial growth factor‑A signaling via neuropilin‑1.
Dehydroepiandrosterone Sulfate and Colorectal Cancer Risk: A Mendelian Randomization Analysis.
NMR analysis suggests the terminal domains of Robo1 remain extended but are rigidified in the presence of heparan sulfate.
Sex steroids and sex steroid-binding globulin levels among middle-aged and elderly men and women from general population.
The Association Between Circulating Sex Hormones and Central Serous Chorioretinopathy: A Case-Control Study.
Redox regulation of enzymes involved in sulfate assimilation and in the synthesis of sulfur-containing amino acids and glutathione in plants.
Modulation of cardiac voltage-activated K+ currents by glypican 1 heparan sulfate proteoglycan.
An N-linked tetrasaccharide from Halobacterium salinarum presents a novel modification, sulfation of iduronic acid at the O-3 position.
Studies of carbohydrate-carbohydrate-interactions by atomic force microscopy employing functionalized 4-acetylthio-butyl glucopyranosides.
Endogenous Levels of Circulating Androgens Are Not Associated with Risk of Microscopic Colitis.
Priapism Secondary to Low-Molecular-Weight Heparins: A Case Report.
The impact of diabetes mellitus type 2 on the steroidogenesis of male Zucker Diabetic Fatty rats.

Nat Commun. 2022 Aug 30. 13(1): 5113

Comprehensive structural assignment of glycosaminoglycan oligo- and polysaccharides by protein nanopore.

Parisa Bayat, Charlotte Rambaud, Bernard Priem, Matthieu Bourderioux, Mélanie Bilong, Salomé Poyer, Manuela Pastoriza-Gallego, Abdelghani Oukhaled, Jérôme Mathé, Régis Daniel.

Glycosaminoglycans are highly anionic functional polysaccharides with information content in their structure that plays a major role in the communication between the cell and the extracellular environment. The study presented here reports the label-free detection and analysis of glycosaminoglycan molecules at the single molecule level using sensing by biological nanopore, thus addressing the need to decipher structural information in oligo- and polysaccharide sequences, which remains a major challenge for glycoscience. We demonstrate that a wild-type aerolysin nanopore can detect and characterize glycosaminoglycan oligosaccharides with various sulfate patterns, osidic bonds and epimers of uronic acid residues. Size discrimination of tetra- to icosasaccharides from heparin, chondroitin sulfate and dermatan sulfate was investigated and we show that different contents and distributions of sulfate groups can be detected. Remarkably, differences in α/β anomerization and 1,4/1,3 osidic linkages can also be detected in heparosan and hyaluronic acid, as well as the subtle difference between the glucuronic/iduronic epimers in chondroitin and dermatan sulfate. Although, at this stage, discrimination of each of the constituent units of GAGs is not yet achieved at the single-molecule level, the resolution reached in this study is an essential step toward this ultimate goal.

DOI: https://doi.org/10.1038/s41467-022-32800-4
Front Mol Biosci. 2022 ;9 912887

Interactions between heparin and SARS-CoV-2 spike glycoprotein RBD from omicron and other variants.

Adrianne L Gelbach, Fuming Zhang, Seok-Joon Kwon, John T Bates, Andrew P Farmer, Jonathan S Dordick, Chunyu Wang, Robert J Linhardt.

  Heparan sulfate (HS) acts as a co-receptor of angiotensin-converting enzyme 2 (ACE2) by interacting with severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) spike glycoprotein (SGP) facilitating host cell entry of SARS-CoV-2 virus. Heparin, a highly sulfated version of heparan sulfate (HS), interacts with a variety of proteins playing key roles in many physiological and pathological processes. In this study, SARS-CoV-2 SGP receptor binding domain (RBD) wild type (WT), Delta and Omicron variants were expressed in Expi293F cells and used in the kinetic and structural analysis on their interactions with heparin. Surface plasmon resonance (SPR) analysis showed the binding kinetics of SGP RBD from WT and Delta variants were very similar while Omicron variant SGP showed a much higher association rate. The SGP from Delta and Omicron showed higher affinity (K D ) to heparin than the WT SGP. Competition SPR studies using heparin oligosaccharides indicated that binding of SGP RBDs to heparin requires chain length greater than 18. Chemically modified heparin derivatives all showed reduced interactions in competition assays suggesting that all the sulfo groups in the heparin polysaccharide were critical for binding SGP RBDs with heparin. These interactions with heparin are pH sensitive. Acidic pH (pH 6.5, 5.5, 4.5) greatly increased the binding of WT and Delta SGP RBDs to heparin, while acidic pH slightly reduced the binding of Omicron SGP RBD to heparin compared to binding at pH 7.3. In contrast, basic pH (pH 8.5) greatly reduced the binding of Omicron SGP RBDs to heparin, with much less effects on WT or Delta. The pH dependence indicates different charged residues were present at the Omicron SGP-heparin interface. Detailed kinetic and structural analysis of the interactions of SARS-CoV-2 SGP RBDs with heparin provides important information for designing anti-SARS-CoV-2 molecules.

Keywords:  SARS-CoV-2; heparan sulfate; heparin; spike protein RBD; surface plasmon resonance

DOI:  https://doi.org/10.3389/fmolb.2022.912887
Colloids Surf B Biointerfaces. 2022 Aug 23. pii: S0927-7765(22)00469-6. [Epub ahead of print]219 112786

Chondroitin sulfate modified chitosan nanoparticles as an efficient and targeted gene delivery vehicle to chondrocytes.

Naghmeh Akbari Moghadam, Fatemeh Bagheri, Mohamadreza Baghaban Eslaminejad.

  Conventional treatments for osteoarthritis (OA), including drug delivery and tissue engineering approaches, could not offer a high yield of cartilage repair due to the compact and exclusive structure of cartilage. Targeted and high-efficiency delivery of gene sequences is necessary to rebalance the lost homeostatic properties of the cartilage in OA. Herein, we synthesized chitosan (CH)-chondroitin sulfate (CS) nanoparticles (NPs) as a platform for delivering gene sequences. These new nanoparticles benefit from two natural polymers that minimize the toxicity, and the presence of CS can be in favor of targeted delivery. The CAG-GFP plasmid was used as a gene sequence model, and the nanoparticles could successfully encapsulate approximately all of them in their structure. Loaded nanoparticles were characterized in terms of morphology, size, zeta potential, the efficiency of encapsulation and, DNA release pattern. Cell viability and uptake of new nanoparticles were compared to the chitosan nanoparticles and Lipofectamine. After substituting TPP with CS, NPs exhibited a significant decrease in size. In addition, there was little difference in zeta potential between nanoparticles. Furthermore, a tremendous increase in plasmid uptake and cell viability was observed by CH-CS NPs compared to CH-TPP NPs and Lipofectamine. In the final stage, the knockdown level of MMP13 was evaluated with real-time RT-PCR for confirming the potential uptake of CH-CS NPs. The results revealed cellular uptake of siRNA loaded NPs and effective knockdown of MMP13 in chondrocytes. In conclusion, CH-CS nanoparticles can be considered as a candidate for gene therapy purposes in cartilage diseases.

Keywords:  Cartilage; Chitosan; Chondroitin sulfate; Gene delivery; Nanoparticles

DOI:  https://doi.org/10.1016/j.colsurfb.2022.112786
Adv Sci (Weinh). 2022 Sep 01. e2202620

Sensory Nerve Maintains Intervertebral Disc Extracellular Matrix Homeostasis Via CGRP/CHSY1 Axis.

Bo Hu, Xiao Lv, Leixin Wei, Yunhao Wang, Genjiang Zheng, Chen Yang, Fazhi Zang, Jianxi Wang, Jing Li, Xiaodong Wu, Zhihao Yue, Qiangqiang Xiao, Zengwu Shao, Wen Yuan, Jinsong Li, Peng Cao, Chen Xu, Huajiang Chen.

  Sensory nerves are long being recognized as collecting units of various outer stimuli; recent advances indicate that the sensory nerve also plays pivotal roles in maintaining organ homeostasis. Here, this study shows that sensory nerve orchestrates intervertebral disc (IVD) homeostasis by regulating its extracellular matrix (ECM) metabolism. Specifically, genetical sensory denervation of IVD results in loss of IVD water preserve molecule chondroitin sulfate (CS), the reduction of CS bio-synthesis gene chondroitin sulfate synthase 1 (CHSY1) expression, and dysregulated ECM homeostasis of IVD. Particularly, knockdown of sensory neuros calcitonin gene-related peptide (CGRP) expression induces similar ECM metabolic disorder compared to sensory nerve denervation model, and this effect is abolished in CHSY1 knockout mice. Furthermore, in vitro evidence shows that CGRP regulates nucleus pulposus cell CHSY1 expression and CS synthesis via CGRP receptor component receptor activity-modifying protein 1 (RAMP1) and cyclic AMP response element-binding protein (CREB) signaling. Therapeutically, local injection of forskolin significantly attenuates IVD degeneration progression in mouse annulus fibrosus puncture model. Overall, these results indicate that sensory nerve maintains IVD ECM homeostasis via CGRP/CHSY1 axis and promotes IVD repair, and this expands the understanding concerning how IVD links to sensory nerve system, thus shedding light on future development of novel therapeutical strategy to IVD degeneration.

Keywords:  chondroitin sulfate; chondroitin sulfate synthase 1; intervertebral disc degeneration; nucleus pulposus; sensory nerves

DOI:  https://doi.org/10.1002/advs.202202620
Int J Oncol. 2022 Oct;pii: 122. [Epub ahead of print]61(4):

Differential dependency of human glioblastoma cells on vascular endothelial growth factor‑A signaling via neuropilin‑1.

Jungwhoi Lee, Kyuha Chong, Jungsul Lee, Chungyeul Kim, Jae-Hoon Kim, Kyungsun Choi, Chulhee Choi.

  Despite the high expression of neuropilin‑1 (NRP‑1) in human glioblastoma (GB), the understanding of its function as a co‑receptor of vascular endothelial growth factor receptors (VEGFRs) in angiogenesis is currently limited. Therefore, the aim of the present study was to elucidate the non‑classical function of NRP‑1 expression in human GB. Expression patterns of NRP‑1 and VEGF‑A were determined by sandwich ELISA, western blot analysis, or immunohistochemistry. Differential dependency of GB cells following ablation of VEGF‑A signaling was validated in vitro and in vivo. Cellular mechanism responsible for distinct response to VEGF‑A signaling was evaluated by western blotting and immunoprecipitation analysis. Prognostic implications were assessed using IHC analysis. GB cells exhibited differing sensitivity to silencing of vascular endothelial growth factor (VEGF)‑A signaling, which resulted in a distinct expression pattern of wild‑type or chondroitin‑sulfated NRP‑1. VEGF‑A‑sensitive GB exhibited the physical interaction between wild‑type NRP‑1 and FMS related receptor tyrosine kinase 1 (Flt‑1) whereas VEGF‑A‑resistant GB exhibited chondroitin‑sulfated NRP‑1 without interaction with Flt‑1. Eliminating the chondroitin sulfate modification in NRP‑1 led to re‑sensitization to VEGF‑A signaling, and chondroitin sulfate modification was found to be associated with an adverse prognosis in patients with GB. The present study identified the distinct functions of NRP‑1 in VEGF‑A signaling in accordance with its unique expression type and interaction with Flt‑1. The present research is expected to provide a strong basis for targeting VEGF‑A signaling in patients with GB, with variable responses.

Keywords:  FMS related receptor tyrosine kinase 1; autocrine signaling; chondroitin sulfate; glioblastoma; neuropilin‑1

DOI:  https://doi.org/10.3892/ijo.2022.5412
Twin Res Hum Genet. 2022 Sep 02. 1-7

Dehydroepiandrosterone Sulfate and Colorectal Cancer Risk: A Mendelian Randomization Analysis.

Dulari K Jayarathna, Miguel E Rentería, Pik Fang Kho, Jyotsna Batra, Neha S Gandhi.

  Colorectal cancer is the third most common and second most deadly type of cancer worldwide, with approximately 1.9 million cases and 0.9 million deaths worldwide in 2020. Previous studies have shown that estrogen and testosterone hormones are associated with colorectal cancer risk and mortality. However, the potential effect of their precursor, dehydroepiandrosterone sulfate (DHEAS), on colorectal cancer risk has not been investigated. Therefore, evaluating DHEAS's effect on colorectal cancer will expand our understanding of the hormonal contribution to colorectal cancer risk. In this study, we conducted a two-sample Mendelian randomization (MR) analysis to investigate the causal effect of DHEAS on colorectal cancer. We obtained DHEAS and colorectal cancer genomewide association study (GWAS) summary statistics from the Leipzig Health Atlas and the GWAS catalog and conducted MR analyses using the TwoSampleMR R package. Our results suggest that higher DHEAS levels are causally associated with decreased colorectal cancer risk (odds ratio per unit increase in DHEAS levels z score = 0.70; 95% confidence interval [0.51, 0.96]), which is in line with previous observations in a case-control study of colon cancer. The outcome of this study will be beneficial in developing plasma DHEAS-based biomarkers in colorectal cancer. Further studies should be conducted to interpret the DHEAS-colorectal cancer association among different ancestries and populations.

Keywords:  Sex hormone precursors; colorectal cancer; dehydroepiandrosterone sulfate; two-sample Mendelian randomization

DOI:  https://doi.org/10.1017/thg.2022.31
Sci Rep. 2022 Aug 30. 12(1): 14769

NMR analysis suggests the terminal domains of Robo1 remain extended but are rigidified in the presence of heparan sulfate.

Robert V Williams, Chin Huang, Kelley W Moremen, I Jonathan Amster, James H Prestegard.

Human roundabout 1 (hRobo1) is an extracellular receptor glycoprotein that plays important roles in angiogenesis, organ development, and tumor progression. Interaction between hRobo1 and heparan sulfate (HS) has been shown to be essential for its biological activity. To better understand the effect of HS binding we engineered a lanthanide-binding peptide sequence (Loop) into the Ig2 domain of hRobo1. Native mass spectrometry was used to verify that loop introduction did not inhibit HS binding or conformational changes previously suggested by gas phase ion mobility measurements. NMR experiments measuring long-range pseudocontact shifts were then performed on 13C-methyl labeled hRobo1-Ig1-2-Loop in HS-bound and unbound forms. The magnitude of most PCSs for methyl groups in the Ig1 domain increase in the bound state confirming a change in the distribution of interdomain geometries. A grid search over Ig1 orientations to optimize the fit of data to a single conformer for both forms produced two similar structures, both of which differ from existing X-ray crystal structures and structures inferred from gas-phase ion mobility measurements. The structures and degree of fit suggest that the hRobo1-Ig1-2 structure changes slightly and becomes more rigid on HS binding. This may have implications for Robo-Slit signaling.

DOI: https://doi.org/10.1038/s41598-022-18769-6
Eur J Clin Invest. 2022 Aug 29. e13866

Sex steroids and sex steroid-binding globulin levels among middle-aged and elderly men and women from general population.

E Aribas, J E Roeters van Lennep, Y B De Rijke, J S E Laven, M A Ikram, R P Peeters, M Kavousi.

   BACKGROUND: Availability of age- and sex-specific reference values for sex steroids and sex steroid-binding globulin (SHBG) levels allows for appropriate interpretation of research findings and their clinical applications. We report the sex-specific distribution and reference levels of sex steroids, including total estradiol, total testosterone and (calculated) free androgen index (cFAI), SHBG and other androgens dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS) and androstenedione across age.
METHODS: Using data from 3291 participants from the prospective population-based Rotterdam Study (2006-2008), we visualized the distribution of sex steroids and SHBG levels by calculating and depicting the 5th , 25th , 50th , 75th , and 95th percentiles per year and per age-year across 5 year age bands to provide reference value ranges in men and women. Total estradiol and SHBG were measured using automated immunoassay and androgens using Liquid Chromatography-Mass Spectrometry (LC-MS/MS).
FINDINGS: Mean age was 56.8 (range 45.6 - 79.9) years in men and 56.9 (range 45.7 - 79.9) years in women. Among men, total estradiol and SHBG showed an increasing trend from 45 years onwards. In women, total estradiol and SHBG showed a decreasing trend from 45 years until the age of 60. From 60 years onwards, SHBG showed an increasing trend. For total testosterone, a clear declining trend was observed among men but not women. Other androgens showed a similar decreasing trend in both sexes from 45 years onwards.
INTERPRETATION: Our study underlines sex-specific trends in sex steroids and SHBG levels with aging. This warrants taking into account sex- and age-specific reference values for sex steroids and SHBG when investigating their impact on health outcomes to prevent controversial results and allow for their appropriate clinical application.

Keywords:  epidemiology; reference values; sex steroid-binding globulin; sex steroids

DOI:  https://doi.org/10.1111/eci.13866
Ther Clin Risk Manag. 2022 ;18 855-865

The Association Between Circulating Sex Hormones and Central Serous Chorioretinopathy: A Case-Control Study.

Chun Zhao, Yan Huang, Lei Chen, Sheng Ye, Xiao-Qiang Liu.

   Background: Central serous chorioretinopathy (CSC) is preferential cocurated in males, however the associations between sex hormones and CSC incidence or progression remains unclear. The sex hormone concentration assessments in CSC cases and healthy controls will update the knowledge in CSC management.
Methods: This case-control study included 59 CSC cases and 30 healthy controls, from January 2019 to December 2020. The CSC cases would be defined as spontaneous resolved if the subretinal fluid were absorbed within three months. The concentrations of total testosterone (TT), free testosterone (FT), estradiol (E2), sex hormone-binding globulin (SHBG), progesterone, leuteinizing hormone (LH) and dehydroepiandrosterone sulfate (DHEA-S) were detected in all the participants. The relationships between sex hormone concentrations and CSC-related characteristics were analyzed with Pearson correlation analyses.
Results: Significantly increased TT, FT, FT/E2 ratio, SHBG concentrations as well as decreased DHEA-S level were detected in non-resolved CSC group compared with the control group. Comparing with the resolved ones, it was found that TT, FT and SHBG concentrations were increased in the non-resolved CSC. A significant positive correlation between TT concentrations and CMT (R2=0.168, P=0.031) as well as SRF height (R2=0.146, P=0.045) were detected in the non-solved CSC group.
Conclusion: Different concentrations of TT, FT, FT/E2 ratio, DHEA-S and SHBG were detected in resolved and non-resolved CSC cases. Sex hormones were related to CSC symptom durations and related parameters.

Keywords:  case-control study; central serous chorioretinopathy; cortisol; sex hormones; testosterone

DOI:  https://doi.org/10.2147/TCRM.S370133
Front Plant Sci. 2022 ;13 958490

Redox regulation of enzymes involved in sulfate assimilation and in the synthesis of sulfur-containing amino acids and glutathione in plants.

Linda de Bont, Natacha Donnay, Jérémy Couturier, Nicolas Rouhier.

  Sulfur is essential in plants because of its presence in numerous molecules including the two amino acids, cysteine, and methionine. Cysteine serves also for the synthesis of glutathione and provides sulfur to many other molecules including protein cofactors or vitamins. Plants absorb sulfate from their environment and assimilate it via a reductive pathway which involves, respectively, a series of transporters and enzymes belonging to multigenic families. A tight control is needed to adjust each enzymatic step to the cellular requirements because the whole pathway consumes energy and produces toxic/reactive compounds, notably sulfite and sulfide. Glutathione is known to regulate the activity of some intermediate enzymes. In particular, it provides electrons to adenosine 5'-phosphosulfate reductases but also regulates the activity of glutamate-cysteine ligase by reducing a regulatory disulfide. Recent proteomic data suggest a more extended post-translational redox control of the sulfate assimilation pathway enzymes and of some associated reactions, including the synthesis of both sulfur-containing amino acids, cysteine and methionine, and of glutathione. We have summarized in this review the known oxidative modifications affecting cysteine residues of the enzymes involved. In particular, a prominent regulatory role of protein persulfidation seems apparent, perhaps because sulfide produced by this pathway may react with oxidized thiol groups. However, the effect of persulfidation has almost not yet been explored.

Keywords:  cysteine; glutathione; methionine; plants; post-translational modifications; redox; sulfate

DOI:  https://doi.org/10.3389/fpls.2022.958490
Life Sci. 2022 Aug 29. pii: S0024-3205(22)00616-6. [Epub ahead of print] 120916

Modulation of cardiac voltage-activated K+ currents by glypican 1 heparan sulfate proteoglycan.

Diego Santos Souza, Andreia Zago Chignalia, Joao Luis Carvalho-de-Souza.

   BACKGROUND: Glypican 1 (Gpc1) is a heparan sulfate proteoglycan attached to the cell membrane via a glycosylphosphatidylinositol anchor, where it holds glycosaminoglycans nearby. We have recently shown that Gpc1 knockout (Gpc1-/-) mice feature decreased systemic blood pressure. To date, none has been reported regarding the role of Gpc1 on the electrical properties of the heart and specifically, in regard to a functional interaction between Gpc1 and voltage-gated K+ channels.
METHODS: We used echocardiography and in vivo (electrocardiographic recordings) and in vitro (patch clamping) electrophysiology to study mechanical and electric properties of mice harts. We used RT-PCR to probe K+ channels' gene transcription in heart tissue.
RESULTS: Gpc1-/- hearts featured increased cardiac stroke volume and preserved ejection fraction. Gpc1-/- electrocardiograms showed longer QT intervals, abnormalities in the ST segment, and delayed T waves, corroborated by longer action potentials in isolated ventricular cardiomyocytes. In voltage-clamp, these cells showed decreased Ito and IK voltage-activated K+ current densities. Moreover, IK showed activation at less negative voltages, but a higher level of inactivation at a given membrane potential. Kcnh2 and Kcnq1 voltage-gated K+ channels subunits' transcripts were remarkably more abundant in heart tissues from Gpc1-/- mice, suggesting that Gpc1 may interfere in the steps between transcription and translation in these cases.
CONCLUSION: Our data reveals an unprecedented connection between Gpc1 and voltage-gated K+ channels expressed in the heart and this knowledge contributes to the understanding of the role of this HSPG in cardiac function which may play a role in the development of cardiovascular disease.

Keywords:  Delayed rectifiers; Glypican 1; Hypertension; Protein-protein interaction; Transient outward current; Voltage-activated K(+) currents

DOI:  https://doi.org/10.1016/j.lfs.2022.120916
Carbohydr Res. 2022 Aug 19. pii: S0008-6215(22)00152-5. [Epub ahead of print]521 108651

An N-linked tetrasaccharide from Halobacterium salinarum presents a novel modification, sulfation of iduronic acid at the O-3 position.

Anna Notaro, Zlata Vershinin, Ziqiang Guan, Jerry Eichler, Cristina De Castro.

Halobacterium salinarum, a halophilic archaeon that grows at near-saturating salt concentrations, provided the first example of N-glycosylation outside Eukarya. Yet, almost 50 years later, numerous aspects of such post-translational protein processing in this microorganism remain to be determined, including the architecture of glycoprotein-bound glycans. In the present report, nuclear magnetic resonance spectroscopy was used to define a tetrasaccharide N-linked to both archaellins, building blocks of the archaeal swimming device (the archaellum), and the S-layer glycoprotein that comprises the protein shell surrounding the Hbt. salinarum cell as β-GlcA(2S)-(1 → 4)-α-IdoA(3S)-(1 → 4)-β-GlcA-(1 → 4)-β-Glc-Asn. The structure of this tetrasaccharide fills gaps remaining from previous studies, including confirmation of the first known inclusion of iduronic acid in an archaeal N-linked glycan. At the same time, the sulfation of this iduronic acid at the O-3 position has not, to the best of our knowledge, been previously seen. As such, this may represent yet another unique facet of N-glycosylation in Archaea.

DOI: https://doi.org/10.1016/j.carres.2022.108651
Carbohydr Res. 2022 Aug 23. pii: S0008-6215(22)00150-1. [Epub ahead of print]521 108649

Studies of carbohydrate-carbohydrate-interactions by atomic force microscopy employing functionalized 4-acetylthio-butyl glucopyranosides.

Julian C Thimm, Eugen Beketow, Joachim Thiem.

  By Fischer glycosylation both anomers of 4-chlorobutyl gluco-as well as galactopyranosides were obtained and transformed into the corresponding 4-acetylthio-butyl glycopyranosides. Dependent on the precursors two straightforward routes were followed to obtain the appropriate 3-O-sulfated derivatives. Unsubstituted and sulfated glucopyranosides were attached to gold surfaces a gold tips. Their interactions were studied using atomic force microscopy for simulations of intercellular glycoside-based interactions and discussed in-depth.

Keywords:  3-O-Sulfates; 4−Acetylthio-butyl gluco- and galactopyranosides; Atomic force microscopy (AFM); Fischer glycosylation; Force sensor experiments; Saccharide-saccharide interdependence; Simulation of intercellular interaction

DOI:  https://doi.org/10.1016/j.carres.2022.108649
Dig Dis Sci. 2022 Aug 30.

Endogenous Levels of Circulating Androgens Are Not Associated with Risk of Microscopic Colitis.

Michaela S Tracy, Prasanna K Challa, Lauren Canha, Kristin Burke, Ashwin N Ananthakrishnan, Emily W Lopes, James M Richter, Andrew T Chan, Hamed Khalili.

   BACKGROUND: Microscopic colitis is a chronic inflammatory disease that most commonly affects post-menopausal women. Exogenous hormone use has recently been linked with increased risk of microscopic colitis. Yet, it is unclear whether levels of endogenous sex hormones are also associated with risk of microscopic colitis.
AIM: To evaluate the association between prediagnostic plasma androgens and subsequent risk of microscopic colitis.
METHODS: We conducted a case-control study nested within prospective cohort studies of the Nurses' Health Study (NHS) and NHSII. Cases of microscopic colitis were each matched to two controls according to age, cohort, menopause status, fasting status, and season of plasma collection. Prediagnosis plasma levels of androgens including dehydroepiandrosterone sulfate, testosterone, and sex hormone-binding globulin were measured. We examined the association of each analyte with risk of microscopic colitis using conditional logistic regression models.
RESULTS: Our study included 96 cases of microscopic colitis matched to 190 controls. Plasma levels of testosterone were not associated with risk of microscopic colitis (Ptrend = 0.70). Compared to participants in the lowest quartile of plasma testosterone levels, the aOR of microscopic colitis for women in the highest quartile was 0.88, 95% CI 0.45-1.71. Similarly, we did not observe an association between dehydroepiandrosterone sulfate and sex hormone-binding globulin and risk of microscopic colitis (all Ptrend > 0.52).
CONCLUSION: Among women, prediagnostic circulating levels of testosterone, dehydroepiandrosterone sulfate, and sex hormone-binding globulin are not associated with risk of microscopic colitis.

Keywords:  Androgens; Collagenous colitis; Lymphocytic colitis; Microscopic colitis; Nurses’ health study

DOI:  https://doi.org/10.1007/s10620-022-07678-3
Acta Med Port. 2022 Aug 29.

Priapism Secondary to Low-Molecular-Weight Heparins: A Case Report.

Joana Liz-Pimenta, Nuno Dias, Miguel Barbosa, Marta Sousa.

  Priapism may be a side effect of low-molecular-weight heparins, and its mechanism remains unknown. The authors present a clinical case of a 51-year-old male patient with oligodendroglioma. The patient presented ischemic priapism on the third month after starting tinzaparin, without other recent changes to his medication and he denied the use of other new medicines. The patient went through surgery and the erection was resolved but presented fibrosis of the cavernous body which left him with erectile dysfunction. Since this event, the patient is no longer receiving Heparin and has had no other episodes of priapism. The prompt recognition of this side effect may decrease its morbidity and consequent impact on the quality of life. More studies are needed to better understand its pathophysiology.

Keywords:  Heparin, Low-Molecular-Weight/adverse effects; Priapism/chemically induced

DOI:  https://doi.org/10.20344/amp.18350
Physiol Res. 2022 Aug 31.

The impact of diabetes mellitus type 2 on the steroidogenesis of male Zucker Diabetic Fatty rats.

F Benko, M Chomová, O Uličná, M Ďuračka, J Kováč, E Tvrdá.

The aim of this study was to evaluate the impact of diabetes mellitus type 2 (DM2) on the male endocrine system of Zucker Diabetic Fatty (ZDF) rats. Sexually mature ZDF rats were divided to a lean (control) and obese group, and had diabetes confirmed by blood tests. For the in vivo experiment, fasting blood was collected to obtain blood plasma. In case of the in vitro experiments, testicular fragments were cultured for 24 h, and the culture medium was collected. The concentrations of testosterone (T), androstenedione (A4), dehydroepiandrosterone (DHEA-S), estradiol (E2), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were quantified in the blood plasma and the medium by the ELISA method, while cholesterol (CHOL) was assessed spectrophotometrically. A significant decline of T (36.31%), A4 (25.11%) and FSH (26.99%) as well as a significant increase of CHOL and E2 (36.17%) was observed in the blood plasma of obese ZDF rats in comparison to the control. Under in vitro conditions, a significant decrease of FSH (23.35%) accompanied by an increase of E2 was observed in the obese group compared to the control. In the case of CHOL, LH, T, DHEA and A4 no significant differences were observed. Our results suggest that except for FSH and E2 all steroid biomolecules were synthetized normally by the testicular tissue, however a dramatic endocrine disturbance was observed at the system level. We may conclude that DM2 has negative effects on systemic hormone secretion and these alterations are more pronounced in combination with obesity.