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Keywords = glycoprotein acetyls

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20 pages, 3857 KiB  
Article
Temporal and Sex-Dependent N-Glycosylation Dynamics in Rat Serum
by Hirokazu Yagi, Sachiko Kondo, Reiko Murakami, Rina Yogo, Saeko Yanaka, Fumiko Umezawa, Maho Yagi-Utsumi, Akihiro Fujita, Masako Okina, Yutaka Hashimoto, Yuji Hotta, Yoichi Kato, Kazuki Nakajima, Jun-ichi Furukawa and Koichi Kato
Int. J. Mol. Sci. 2025, 26(15), 7266; https://doi.org/10.3390/ijms26157266 - 27 Jul 2025
Viewed by 408
Abstract
We conducted systematic glycomic and glycoproteomic profiling to characterize the dynamic N-glycosylation landscape of rat serum, with particular focus on sex- and time-dependent variations. MALDI-TOF-MS analysis revealed that rat serum N-glycans are predominantly biantennary, disialylated complex-type structures with extensive O-acetylation [...] Read more.
We conducted systematic glycomic and glycoproteomic profiling to characterize the dynamic N-glycosylation landscape of rat serum, with particular focus on sex- and time-dependent variations. MALDI-TOF-MS analysis revealed that rat serum N-glycans are predominantly biantennary, disialylated complex-type structures with extensive O-acetylation of Neu5Ac residues, especially in females. LC-MS/MS-based glycoproteomic analysis of albumin/IgG-depleted serum identified 87 glycoproteins enriched in protease inhibitors (e.g., serine protease inhibitor A3K) and immune-related proteins such as complement C3. Temporal analyses revealed stable sialylation in males but pronounced daily fluctuations in females, suggesting hormonal influence. Neu5Gc-containing glycans were rare and mainly derived from residual IgG, as confirmed by glycomic analysis. In contrast to liver-derived glycoproteins, purified IgG exhibited Neu5Gc-only sialylation without O-acetylation, underscoring distinct sialylation profiles characteristic of B cell-derived glycoproteins. Region-specific glycosylation patterns were observed in IgG, with the Fab region carrying more disialylated structures than Fc. These findings highlight cell-type and sex-specific differences in sialylation patterns between hepatic and immune tissues, with implications for hormonal regulation and biomarker research. This study provides a valuable dataset on rat serum glycoproteins and underscores the distinctive glycosylation features of rats, reinforcing their utility as model organisms in glycobiology and disease research. Full article
(This article belongs to the Special Issue Glycobiology of Health and Diseases)
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18 pages, 1899 KiB  
Systematic Review
Exploring Metabolic Signatures: Unraveling the Association with Obesity in Children and Adolescents
by Diamanto Koutaki, Garyfallia Stefanou, Sofia-Maria Genitsaridi, Eleni Ramouzi, Athanasia Kyrkili, Meropi D. Kontogianni, Eleni Kokkou, Eleni Giannopoulou, Penio Kassari and Evangelia Charmandari
Nutrients 2025, 17(11), 1833; https://doi.org/10.3390/nu17111833 - 28 May 2025
Viewed by 596
Abstract
Background: Childhood obesity is a growing global health concern. Metabolomics, the comprehensive study of metabolites within biological systems, offers a powerful approach to better define the phenotype and understand the complex biochemical alterations associated with obesity. The aim of this systematic review was [...] Read more.
Background: Childhood obesity is a growing global health concern. Metabolomics, the comprehensive study of metabolites within biological systems, offers a powerful approach to better define the phenotype and understand the complex biochemical alterations associated with obesity. The aim of this systematic review was to summarize current knowledge in the field of metabolomics in childhood obesity and to identify metabolic signatures or biomarkers associated with overweight/obesity (Ov/Ob) and Metabolically Unhealthy Obesity (MUO) in children and adolescents. Methods: We performed a systematic search of Medline and Scopus databases according to PRISMA guidelines. We included only longitudinal prospective studies or randomized controlled trials with ≥12 months of follow-up, as well as meta-analyses of the above that assessed the relation between metabolic signatures related to obesity and Body Mass Index (BMI) or other measures of adiposity in children and adolescents aged 2–19 years with overweight or obesity. Initially, 595 records were identified from PubMed and 1565 from Scopus. After removing duplicates and screening for relevance, 157 reports were assessed for eligibility. From the additional search, 75 new records were retrieved, of which none were eligible for our study. Finally, 7 reports were included in the present systematic review (4 reporting on Ov/Ob and 4 on MUO). Results: The presented studies suggest that the metabolism of amino acids and lipids is primarily affected by childhood obesity. Metabolites like glycoprotein acetyls, the Apolipoprotein B/Apolipoprotein A-1 ratio, and lactate have emerged as potential biomarkers for insulin resistance and metabolic syndrome, highlighting their potential value in clinical applications. Conclusions: There is a need for future longitudinal studies to assess metabolic changes over time, interventional studies to evaluate the efficacy of therapeutic strategies, and large-scale population studies to explore metabolic diversity across different demographics. Our findings reveal specific biomarkers in the amino acid and lipid pathway that may serve as early indicators of childhood obesity and its associated cardiometabolic complications. Full article
(This article belongs to the Section Pediatric Nutrition)
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19 pages, 3174 KiB  
Article
Expression of 9-O-Acetylated Sialic Acid in HPV+ Oral Squamous Cell Carcinoma Cells
by Hugo Sánchez-Martínez, Victoria Jiménez-Castillo, Daniela Illescas-Barbosa, Beatriz Xochitl Ávila-Curiel, María Teresa Hernández-Huerta, Risk Díaz-Castillejos, Rafael Torres-Rosas, Edgar Zenteno, Mohamed Alí Pereyra-Morales and Carlos Josué Solórzano-Mata
Life 2025, 15(4), 663; https://doi.org/10.3390/life15040663 - 17 Apr 2025
Viewed by 1064
Abstract
Oral squamous cell carcinoma (OSCC) is a common type of head and neck malignancy that represents a significant global health issue. Sialylations are common events in tumor transformation, proliferation, metastasis, and immune evasion. Modifications in sialylation can be detected by lectins, whose changes [...] Read more.
Oral squamous cell carcinoma (OSCC) is a common type of head and neck malignancy that represents a significant global health issue. Sialylations are common events in tumor transformation, proliferation, metastasis, and immune evasion. Modifications in sialylation can be detected by lectins, whose changes in OSCC have been related to grade, invasion, and metastasis. The presence of 9-O-acetylated sialic acid (Neu5,9Ac2) in OSCC cells and its potential expression, modification, and role are unknown. This study aimed to analyze the expression of Neu5,9Ac2 using the Macrobrachium rosenbergii lectin (MrL) that recognizes this sialic acid (Neu5Ac) residue and also compare its effect on the SCC-152 cell line (CRL-3240, ATCC) and immortalized keratinocytes (HaCaT) as a control. We observed by immunocytochemistry that SCC-152 cells expressed more Neu5,9Ac2 compared to HaCaT cells; the specificity of MrL was confirmed after the sialidase treatment of cells in which the loss of lectin’s recognition of Neu5,9Ac2 was observed. The electrophoretic profile was similar between both cell line types; however, the Western blot showed differences in the glycoprotein patterns recognized by lectin for each cell type. MrL increased the proliferation of SCC-152 cells, as well as the integrity and morphology of the colonies. Therefore, our results suggest that Neu5,9Ac2 glycosylated receptors could be involved in the survival and proliferation of OSCC cells, which offers a promising avenue for developing diagnostic and prognostic tools (tumor markers) against oral squamous cell carcinoma in the future. Full article
(This article belongs to the Special Issue Sialic Acid and Sialic Acid Derivatives in Biomedicine)
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15 pages, 4783 KiB  
Article
Sucralose Promotes Benzo(a)Pyrene-Induced Renal Toxicity in Mice by Regulating P-glycoprotein
by Jun Hu, Ji Feng, Yan Bai, Zhi-Sheng Yao, Xiao-Yu Wu, Xin-Yu Hong, Guo-Dong Lu and Kun Xue
Antioxidants 2025, 14(4), 474; https://doi.org/10.3390/antiox14040474 - 16 Apr 2025
Cited by 1 | Viewed by 806
Abstract
Background: Sucralose and benzo(a)pyrene (B[a]P) are widespread foodborne substances known to harm human health. However, the effects of their combined exposure on kidney function remain unclear. This study aimed to investigate the mechanisms by which sucralose and B[a]P induce [...] Read more.
Background: Sucralose and benzo(a)pyrene (B[a]P) are widespread foodborne substances known to harm human health. However, the effects of their combined exposure on kidney function remain unclear. This study aimed to investigate the mechanisms by which sucralose and B[a]P induce kidney injury through P-glycoprotein (PGP/ABCB1), a crucial protein involved in cellular detoxification. Methods: C57BL/6N mice were co-treated with sucralose and B[a]P for 90 days to evaluate their impact on kidney histopathology and function. In vitro experiments assessed cell viability, reactive oxygen species (ROS) levels, and B[a]P accumulation by flow cytometry. Molecular docking and cellular thermal shift assay (CETSA) were used to determine the binding affinity of sucralose to PGP. Furthermore, PCR, Western blotting, and immunohistochemistry were performed to analyze the expression of PGP and its upstream transcription factors. Results: Ninety days of co-exposure to sucralose and B[a]P significantly exacerbated renal dysfunction in mice, as evidenced by the elevated level of serum creatinine and urea nitrogen, which could be reverted by ROS scavenger N-acetyl cysteine (NAC). In vitro, sucralose promoted cellular accumulation of B[a]P, consequently enhancing B[a]P-induced cell growth inhibition and ROS production. Consistently, B[a]P accumulation was enhanced by PGP knockdown in both HK2 and HEK-293 cells. Mechanistically, sucralose can directly bind to PGP, competitively inhibiting its efflux capacity and increasing intracellular B[a]P retention. Prolonged co-exposure further downregulated PGP expression, possibly through the reductions of its transcriptional regulators (PXR, NRF2, and NF-κB). Conclusions: Co-exposure to sucralose and B[a]P exacerbates renal injury by impairing PGP function. Mechanistically, sucralose inhibits PGP activity, resulting in the accumulation of B[a]P within renal cells. This accumulation triggers oxidative stress and inhibits cell growth, which demonstrates that sucralose potentiates B[a]P-induced nephrotoxicity by directly inhibiting PGP-mediated detoxification pathways, thus underscoring the critical need to evaluate toxicity risks associated with combined exposure to these compounds. Full article
(This article belongs to the Section Health Outcomes of Antioxidants and Oxidative Stress)
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15 pages, 2546 KiB  
Article
Unraveling the Molecular Mechanisms of Synthetic Acetyl Hexapeptide in E-Cadherin Activation for Tissue Rejuvenation
by Nikoleta Topouzidou, Androulla N. Miliotou, Danai Nodaraki, Eleftheria Galatou, Christos Petrou and Yiannis Sarigiannis
Cosmetics 2025, 12(2), 48; https://doi.org/10.3390/cosmetics12020048 - 12 Mar 2025
Viewed by 2059
Abstract
Objective: Dermo-cosmetics have significantly advanced, focusing on innovative and effective products such as cosmeceuticals—cosmetics infused with bioactive ingredients for skin benefits. Synthetic peptides are prominent among these bioactive molecules, noted for their enhanced effects in cellular processes related to skin physiology. Specifically, the [...] Read more.
Objective: Dermo-cosmetics have significantly advanced, focusing on innovative and effective products such as cosmeceuticals—cosmetics infused with bioactive ingredients for skin benefits. Synthetic peptides are prominent among these bioactive molecules, noted for their enhanced effects in cellular processes related to skin physiology. Specifically, the glycoprotein E-cadherin plays a crucial role in cellular adhesion and has shown promise in wound healing studies, although its broader cellular functions remain underexplored. Despite their widespread use, many cosmetic peptides lack genetic validation of their effects. This study focuses on the synthetic, amphiphilic acetyl hexapeptide-1, aimed to possess wound healing and anti-aging properties, with a novel exploration of its molecular mechanisms, specifically its effect on the expression of the CDH-1 gene, which encodes E-cadherin—a key protein in cellular adhesion and wound healing. Methods: In this investigation, the acetyl hexapeptide-1 was synthesized in house, followed by cell culture assessment and molecular evaluation. Human hepatocytes HepG2 were exposed to the synthetic hexapeptide to assess cytotoxic effects and examine its impact on gene expression, specifically targeting the wound healing-associated gene CDH-1, as well as apoptosis-related genes BAX, Bcl-2, Caspase-9, and Cyclin D1. Results: No cytotoxic effects were observed in cell cultures. Gene expression analysis revealed a significant increase in E-cadherin expression, along with the NO modulation of apoptosis-related genes (BAX, Bcl-2, Caspase-9) and the cell cycle-related gene Cyclin D1. These findings suggest peptide’s role in enhancing cellular adhesion, without any cytotoxic effects. Conclusions: The findings of this study provide promising insights into the potential molecular properties of synthetic acetyl hexapeptide-1, implying its applicability in cosmeceuticals. These cosmetic peptides hold enormous potential and diverse applications not only within skincare. To fully understand their benefits and expand their scope, additional investigations are warranted to comprehensively explore their molecular mechanisms across a spectrum of applications. Full article
(This article belongs to the Section Cosmetic Dermatology)
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10 pages, 1061 KiB  
Article
Low GCNT2/I-Branching Glycan Expression Is Associated with Bladder Cancer Aggressiveness
by Yuki Tobisawa, Keita Nakane, Takuya Koie, Tomoki Taniguchi, Masayuki Tomioka, Risa Tomioka-Inagawa, Kota Kawase, Makoto Kawase and Koji Iinuma
Biomedicines 2025, 13(3), 682; https://doi.org/10.3390/biomedicines13030682 - 10 Mar 2025
Viewed by 752
Abstract
Background/Objectives: Abnormal glycan formation on the cancer cell surface plays a crucial role in regulating tumor functions in bladder cancer. In this study, we investigated the roles of glucosaminyl (N-acetyl) transferase 2 (GCNT2) in bladder cancer progression and immune evasion. GCNT2 [...] Read more.
Background/Objectives: Abnormal glycan formation on the cancer cell surface plays a crucial role in regulating tumor functions in bladder cancer. In this study, we investigated the roles of glucosaminyl (N-acetyl) transferase 2 (GCNT2) in bladder cancer progression and immune evasion. GCNT2 synthesizes I-branched polylactosamine chains on cell surface glycoproteins. Understanding its functions will provide insights into tumor–immune interactions, facilitating the development of effective immunotherapeutic strategies. Methods: GCNT2 expression levels in bladder cancer cell lines and patient tumor samples were analyzed via quantitative polymerase chain reaction and immunohistochemistry. GCNT2 functions were assessed via overexpression and knockdown experiments. Its effect on natural killer (NK) cell-mediated cytotoxicity was evaluated via in vitro assay. Cytotoxic granule release from NK cells was measured via enzyme-linked immunosorbent assay. Results: GCNT2 expression was inversely correlated with bladder cancer aggressiveness in both cell lines and patient samples. Low GCNT2 levels were associated with advanced tumor stage and grade, suggesting the tumor-suppressive roles of GCNT2. Notably, GCNT2 overexpression enhanced the susceptibility of bladder cancer cells to NK cell-mediated killing, whereas its knockdown promoted immune evasion. GCNT2-overexpressing cells strongly induced the release of cytotoxic granules from NK cells, indicating enhanced immune recognition. Conclusions: Our findings suggest that aggressive bladder tumors evade NK cell immunity by decreasing the GCNT2 levels and that I-antigen glycans synthesized by GCNT2 are crucial for NK cell recognition by tumor cells. Our findings provide insights into the tumor–immune interactions in bladder cancer and GCNT2 and its associated pathways as potential targets for novel immunotherapeutic strategies. Full article
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35 pages, 10583 KiB  
Article
Leveraging Artificial Intelligence and Gene Expression Analysis to Identify Some Potential Bovine Coronavirus (BCoV) Receptors and Host Cell Enzymes Potentially Involved in the Viral Replication and Tissue Tropism
by Mohd Yasir Khan, Abid Ullah Shah, Nithyadevi Duraisamy, Reda Nacif ElAlaoui, Mohammed Cherkaoui and Maged Gomaa Hemida
Int. J. Mol. Sci. 2025, 26(3), 1328; https://doi.org/10.3390/ijms26031328 - 4 Feb 2025
Cited by 1 | Viewed by 1290
Abstract
Bovine coronavirus (BCoV) exhibits dual tissue tropism, infecting both the respiratory and enteric tracts of cattle. Viral entry into host cells requires a coordinated interaction between viral and host proteins. However, the specific cellular receptors and co-receptors facilitating BCoV entry remain poorly understood. [...] Read more.
Bovine coronavirus (BCoV) exhibits dual tissue tropism, infecting both the respiratory and enteric tracts of cattle. Viral entry into host cells requires a coordinated interaction between viral and host proteins. However, the specific cellular receptors and co-receptors facilitating BCoV entry remain poorly understood. Similarly, the roles of host proteases such as Furin, TMPRSS2, and Cathepsin-L (CTS-L), known to assist in the replication of other coronaviruses, have not been extensively explored for BCoV. This study aims to identify novel BCoV receptors and host proteases that modulate viral replication and tissue tropism. Bovine cell lines were infected with BCoV isolates from enteric and respiratory origins, and the host cell gene expression profiles post-infection were analyzed using next-generation sequencing (NGS). Differentially expressed genes encoding potential receptors and proteases were further assessed using in-silico prediction and molecular docking analysis. These analyses focused on known coronavirus receptors, including ACE2, NRP1, DPP4, APN, AXL, and CEACAM1, to identify their potential roles in BCoV infection. Validation of these findings was performed using the qRT-PCR assays targeting individual genes. We confirmed the gene expression profiles of these receptors and enzymes in some BCoV (+/−) lung tissues. Results revealed high binding affinities of 9-O-acetylated sialic acid and NRP1 to BCoV spike (S) and hemagglutinin-esterase (HE) proteins compared to ACE2, DPP4, and CEACAM1. Additionally, Furin and TMPRSS2 were predicted to interact with the BCoV-S polybasic cleavage site (RRSRR|A), suggesting their roles in S glycoprotein activation. This is the first study to explore the interactions of BCoV with multiple host receptors and proteases. Functional studies are recommended to confirm their roles in BCoV infection and replication. Full article
(This article belongs to the Special Issue Molecular Design of Artificial Receptors Using Virtual Approaches)
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28 pages, 3458 KiB  
Review
Decoding Cancer through Silencing the Mitochondrial Gatekeeper VDAC1
by Tasleem Arif, Anna Shteinfer-Kuzmine and Varda Shoshan-Barmatz
Biomolecules 2024, 14(10), 1304; https://doi.org/10.3390/biom14101304 - 15 Oct 2024
Cited by 2 | Viewed by 3690
Abstract
Mitochondria serve as central hubs for regulating numerous cellular processes that include metabolism, apoptosis, cell cycle progression, proliferation, differentiation, epigenetics, immune signaling, and aging. The voltage-dependent anion channel 1 (VDAC1) functions as a crucial mitochondrial gatekeeper, controlling the flow of ions, such as [...] Read more.
Mitochondria serve as central hubs for regulating numerous cellular processes that include metabolism, apoptosis, cell cycle progression, proliferation, differentiation, epigenetics, immune signaling, and aging. The voltage-dependent anion channel 1 (VDAC1) functions as a crucial mitochondrial gatekeeper, controlling the flow of ions, such as Ca2+, nucleotides, and metabolites across the outer mitochondrial membrane, and is also integral to mitochondria-mediated apoptosis. VDAC1 functions in regulating ATP production, Ca2+ homeostasis, and apoptosis, which are essential for maintaining mitochondrial function and overall cellular health. Most cancer cells undergo metabolic reprogramming, often referred to as the “Warburg effect”, supplying tumors with energy and precursors for the biosynthesis of nucleic acids, phospholipids, fatty acids, cholesterol, and porphyrins. Given its multifunctional nature and overexpression in many cancers, VDAC1 presents an attractive target for therapeutic intervention. Our research has demonstrated that silencing VDAC1 expression using specific siRNA in various tumor types leads to a metabolic rewiring of the malignant cancer phenotype. This results in a reversal of oncogenic properties that include reduced tumor growth, invasiveness, stemness, epithelial–mesenchymal transition. Additionally, VDAC1 depletion alters the tumor microenvironment by reducing angiogenesis and modifying the expression of extracellular matrix- and structure-related genes, such as collagens and glycoproteins. Furthermore, VDAC1 depletion affects several epigenetic-related enzymes and substrates, including the acetylation-related enzymes SIRT1, SIRT6, and HDAC2, which in turn modify the acetylation and methylation profiles of histone 3 and histone 4. These epigenetic changes can explain the altered expression levels of approximately 4000 genes that are associated with reversing cancer cells oncogenic properties. Given VDAC1’s critical role in regulating metabolic and energy processes, targeting it offers a promising strategy for anti-cancer therapy. We also highlight the role of VDAC1 expression in various disease pathologies, including cardiovascular, neurodegenerative, and viral and bacterial infections, as explored through siRNA targeting VDAC1. Thus, this review underscores the potential of targeting VDAC1 as a strategy for addressing high-energy-demand cancers. By thoroughly understanding VDAC1’s diverse roles in metabolism, energy regulation, mitochondrial functions, and other cellular processes, silencing VDAC1 emerges as a novel and strategic approach to combat cancer. Full article
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12 pages, 255 KiB  
Article
Association of Maternal Air Pollution Exposure and Infant Lung Function Is Modified by Genetic Propensity to Oxidative Stress
by Dwan Vilcins, Wen Ray Lee, Cindy Pham, Sam Tanner, Luke D. Knibbs, David Burgner, Tamara L. Blake, Toby Mansell, Anne-Louise Ponsonby, Peter D. Sly and Barwon Infant Study Investigator Group
Children 2024, 11(8), 937; https://doi.org/10.3390/children11080937 - 31 Jul 2024
Viewed by 1886
Abstract
Background and objective: The association between air pollution and poor respiratory health outcomes is well established. Children are particularly at risk from air pollution, especially during the prenatal period as their organs and systems are still undergoing crucial development. This study investigated maternal [...] Read more.
Background and objective: The association between air pollution and poor respiratory health outcomes is well established. Children are particularly at risk from air pollution, especially during the prenatal period as their organs and systems are still undergoing crucial development. This study investigated maternal exposure to air pollution during pregnancy and oxidative stress (OS), inflammation, and infant lung function at 4 weeks of age. Methods: Data from the Barwon Infant Study were available for 314 infants. The exposure to NO2 and PM2.5 were estimated. Infant lung function (4 weeks) was measured by multiple-breath washout. Glycoprotein acetyls (GlycA) (36 weeks prenatal), cord blood, and OS biomarkers were measured in maternal urine (28 weeks). A genetic pathway score for OS (gPFSox) was calculated. Linear regression was used and potential modification by the OS genotype was tested. Results: There was no relationship between maternal exposure to air pollution and infant lung function, or with GlycA or OS during pregnancy. We found an association in children with a genetic propensity to OS between NO2 and a lower functional residual capacity (FRC) (β = −5.3 mls, 95% CI (−9.3, −1.3), p = 0.01) and lung clearance index (LCI) score (β = 0.46 turnovers, (95% CI 0.10, 0.82), p = 0.01). Conclusion: High prenatal exposure to ambient NO2 is associated with a lower FRC and a higher LCI score in infants with a genetic propensity to oxidative stress. There was no relationship between maternal exposure to air pollution with maternal and cord blood inflammation or OS biomarkers. Full article
(This article belongs to the Special Issue Updates on Lung Function, Respiratory and Asthma Disease in Children)
14 pages, 1834 KiB  
Article
Characterization of the Neurospora crassa Galactosaminogalactan Biosynthetic Pathway
by Apurva Chatrath, Protyusha Dey, Kevin Greeley, Gabriela Maciel, Lei Huang, Christian Heiss, Ian Black, Parastoo Azadi and Stephen J. Free
Microorganisms 2024, 12(8), 1509; https://doi.org/10.3390/microorganisms12081509 - 23 Jul 2024
Cited by 1 | Viewed by 1409
Abstract
The Neurospora crassa genome has a gene cluster for the synthesis of galactosaminogalactan (GAG). The gene cluster includes the following: (1) UDP-glucose-4-epimerase to convert UDP-glucose and UDP-N-acetylglucosamine to UDP-galactose and UDP-N-acetylgalactosamine (NCU05133), (2) GAG synthase for the synthesis of [...] Read more.
The Neurospora crassa genome has a gene cluster for the synthesis of galactosaminogalactan (GAG). The gene cluster includes the following: (1) UDP-glucose-4-epimerase to convert UDP-glucose and UDP-N-acetylglucosamine to UDP-galactose and UDP-N-acetylgalactosamine (NCU05133), (2) GAG synthase for the synthesis of an acetylated GAG (NCU05132), (3) GAG deacetylase (/NCW-1/NCU05137), (4) GH135-1, a GAG hydrolase with specificity for N-acetylgalactosamine-containing GAG (NCU05135), and (5) GH114-1, a galactosaminidase with specificity for galactosamine-containing GAG (NCU05136). The deacetylase was previously shown to be a major cell wall glycoprotein and given the name of NCW-1 (non-GPI anchored cell wall protein-1). Characterization of the polysaccharides found in the growth medium from the wild type and the GAG synthase mutant demonstrates that there is a major reduction in the levels of polysaccharides containing galactosamine and N-acetylgalactosamine in the mutant growth medium, providing evidence that the synthase is responsible for the production of a GAG. The analysis also indicates that there are other galactose-containing polysaccharides produced by the fungus. Phenotypic characterization of wild-type and mutant isolates showed that deacetylated GAG from the wild type can function as an adhesin to a glass surface and provides the fungal mat with tensile strength, demonstrating that the deacetylated GAG functions as an intercellular adhesive. The acetylated GAG produced by the deacetylase mutant was found to function as an adhesive for chitin, alumina, celite (diatomaceous earth), activated charcoal, and wheat leaf particulates. Full article
(This article belongs to the Section Molecular Microbiology and Immunology)
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21 pages, 621 KiB  
Article
Glycoprotein Acetyls Is a Novel Biomarker Predicting Cardiovascular Complications in Rheumatoid Arthritis
by Melody Kasher, Maxim B. Freidin, Frances M. K. Williams, Stacey S. Cherny, Shai Ashkenazi and Gregory Livshits
Int. J. Mol. Sci. 2024, 25(11), 5981; https://doi.org/10.3390/ijms25115981 - 30 May 2024
Cited by 2 | Viewed by 2203
Abstract
The relationship between rheumatoid arthritis (RA) and early onset atherosclerosis is well depicted, each with an important inflammatory component. Glycoprotein acetyls (GlycA), a novel biomarker of inflammation, may play a role in the manifestation of these two inflammatory conditions. The present study examined [...] Read more.
The relationship between rheumatoid arthritis (RA) and early onset atherosclerosis is well depicted, each with an important inflammatory component. Glycoprotein acetyls (GlycA), a novel biomarker of inflammation, may play a role in the manifestation of these two inflammatory conditions. The present study examined a potential mediating role of GlycA within the RA–atherosclerosis relationship to determine whether it accounts for the excess risk of cardiovascular disease over that posed by lipid risk factors. The UK Biobank dataset was acquired to establish associations among RA, atherosclerosis, GlycA, and major lipid factors: total cholesterol (TC), high- and low-density lipoprotein (HDL, LDL) cholesterol, and triglycerides (TGs). Genome-wide association study summary statistics were collected from various resources to perform genetic analyses. Causality among variables was tested using Mendelian Randomization (MR) analysis. Genes of interest were identified using colocalization analysis and gene enrichment analysis. MR results appeared to indicate that the genetic relationship between GlycA and RA and also between RA and atherosclerosis was explained by horizontal pleiotropy (p-value = 0.001 and <0.001, respectively), while GlycA may causally predict atherosclerosis (p-value = 0.017). Colocalization analysis revealed several functionally relevant genes shared between GlycA and all the variables assessed. Two loci were apparent in all relationships tested and included the HLA region as well as SLC22A1. GlycA appears to mediate the RA–atherosclerosis relationship through several possible pathways. GlycA, although pleiotropically related to RA, appears to causally predict atherosclerosis. Thus, GlycA is suggested as a significant factor in the etiology of atherosclerosis development in RA. Full article
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18 pages, 359 KiB  
Article
GlycA and CRP Are Genetically Correlated: Insight into the Genetic Architecture of Inflammageing
by Melody Kasher, Maxim B. Freidin, Frances M. K. Williams, Gregory Livshits and CHARGE Inflammation Working Group
Biomolecules 2024, 14(5), 563; https://doi.org/10.3390/biom14050563 - 8 May 2024
Cited by 2 | Viewed by 2503
Abstract
Inflammageing is a condition of perpetual low-grade inflammation induced by ageing. Inflammageing may be predicted by the C-reactive protein (CRP) or by a recently described biomarker which measures N-glycosylated side chains of the carbohydrate component of several acute-phase proteins known as GlycA. The [...] Read more.
Inflammageing is a condition of perpetual low-grade inflammation induced by ageing. Inflammageing may be predicted by the C-reactive protein (CRP) or by a recently described biomarker which measures N-glycosylated side chains of the carbohydrate component of several acute-phase proteins known as GlycA. The objective of this study was to examine in depth the genetic relationships between CRP and GlycA as well as between each of them and other selected cytokines, which may shed light on the mechanisms of inflammageing. Using the Olink 96 Inflammation panel, data on inflammatory mediators for 1518 twins from the TwinsUK dataset were acquired. Summary statistics for genome-wide association studies for several cytokines as well as CRP and GlycA were collected from public sources. Extensive genetic correlation analyses, colocalization and genetic enrichment analyses were carried out to detect the shared genetic architecture between GlycA and CRP. Mendelian randomization was carried out to assess potential causal relationships. GlycA predicted examined cytokines with a magnitude twice as great as that of CRP. GlycA and CRP were significantly genetically correlated (Rg = 0.4397 ± 0.0854, p-value = 2.60 × 10−7). No evidence of a causal relationship between GlycA and CRP, or between these two biomarkers and the cytokines assessed was obtained. However, the aforementioned relationships were explained well by horizontal pleiotropy. Five exonic genetic variants annotated to five genes explain the shared genetic architecture observed between GlycA and CRP: IL6R, GCKR, MLXIPL, SERPINA1, and MAP1A. GlycA and CRP possess a shared genetic architecture, but the relationship between them appears to be modest, which may imply the promotion of differing inflammatory pathways. GlycA appears to be a more robust predictor of cytokines compared to CRP. Full article
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14 pages, 3265 KiB  
Article
Peak Resembling N-acetylaspartate (NAA) on Magnetic Resonance Spectroscopy of Brain Metastases
by Jelena Ostojic, Dusko Kozic, Milana Panjkovic, Biljana Georgievski-Brkic, Dusan Dragicevic, Aleksandra Lovrenski and Jasmina Boban
Medicina 2024, 60(4), 662; https://doi.org/10.3390/medicina60040662 - 19 Apr 2024
Viewed by 4022
Abstract
Background and Objectives: Differentiating between a high-grade glioma (HGG) and solitary cerebral metastasis presents a challenge when using standard magnetic resonance imaging (MRI) alone. Magnetic resonance spectroscopy (MRS), an advanced MRI technique, may assist in resolving this diagnostic dilemma. N-acetylaspartate (NAA), an [...] Read more.
Background and Objectives: Differentiating between a high-grade glioma (HGG) and solitary cerebral metastasis presents a challenge when using standard magnetic resonance imaging (MRI) alone. Magnetic resonance spectroscopy (MRS), an advanced MRI technique, may assist in resolving this diagnostic dilemma. N-acetylaspartate (NAA), an amino acid found uniquely in the central nervous system and in high concentrations in neurons, typically suggests HGG over metastatic lesions in spectra from ring-enhancing lesions. This study investigates exceptions to this norm. Materials and Methods: We conducted an MRS study on 49 histologically confirmed and previously untreated patients with brain metastases, employing single-voxel (SVS) techniques with short and long echo times, as well as magnetic resonance spectroscopic imaging (MRSI). Results: In our cohort, 44 out of 49 (90%) patients demonstrated a typical MR spectroscopic profile consistent with secondary deposits: a Cho peak, very low or absent Cr, absence of NAA, and the presence of lipids. A peak at approximately 2 ppm, termed the “NAA-like peak”, was present in spectra obtained with both short and long echo times. Among the MRS data from 49 individuals, we observed a peak at 2.0 ppm in five brain metastases from mucinous carcinoma of the breast, mucinous non-small-cell lung adenocarcinoma, two metastatic melanomas, and one metastatic non-small-cell lung cancer. Pathohistological verification of mucin in two of these five cases suggested this peak likely represents N-acetyl glycoproteins, indicative of mucin expression in cancer cells. Conclusions: The identification of a prominent peak at 2.0 ppm could be a valuable diagnostic marker for distinguishing single ring-enhancing lesions, potentially associated with mucin-expressing metastases, offering a new avenue for diagnostic specificity in challenging cases. Full article
(This article belongs to the Section Oncology)
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11 pages, 819 KiB  
Article
GlycA: Evaluation of a New Biomarker of Acute Pancreatitis
by Ishani Shah, William Yakah, Awais Ahmed, Steven D. Freedman, Zhenghui G. Jiang and Sunil G. Sheth
Biomolecules 2023, 13(10), 1530; https://doi.org/10.3390/biom13101530 - 16 Oct 2023
Cited by 2 | Viewed by 2038
Abstract
Background: Acute pancreatitis (AP) is a leading cause of gastrointestinal hospital admissions, with up to 40% mortality in patients with moderate–severe AP. Glycoprotein acetylation (GlycA) is measured as a nuclear magnetic resonance signal (NMR) of the post-translational modification of glycosylated acute-phase proteins released [...] Read more.
Background: Acute pancreatitis (AP) is a leading cause of gastrointestinal hospital admissions, with up to 40% mortality in patients with moderate–severe AP. Glycoprotein acetylation (GlycA) is measured as a nuclear magnetic resonance signal (NMR) of the post-translational modification of glycosylated acute-phase proteins released during inflammation. We aimed to investigate the role of GlycA as an inflammatory biomarker of AP. Methods: We prospectively enrolled 20 AP patients and 22 healthy controls and collected EDTA plasma samples at admission and discharge. NMR spectra were acquired from these samples using a 400 MHz Vantera® Clinical Analyzer, and GlycA concentrations were calculated (normal = 400 μmol/L). The GlycA NMR signal, at 2.00 ± 0.01 ppm in the NMR spectrum, is derived from the N-acetyl methyl group protons within the carbohydrate side chains of circulating glycoproteins such as α1-acid glycoprotein, haptoglobin, α1-antitrypsin, α1-antichymotrypsin, and transferrin. GlycA levels were then compared between AP patients and controls, as well as within the AP group, based on etiology and severity. Results: Demographic comparisons were similar, except for a higher BMI in AP patients compared to healthy controls (29.9 vs. 24.8 kg/m2; p < 0.001). AP was mild in 10 patients, moderate in 7, and severe in 3. GlycA levels were higher in AP patients than healthy controls on admission (578 vs. 376 μmol/L, p < 0.001) and at discharge (655 vs. 376 μmol/L, p < 0.001). GlycA levels were significantly higher in patients with moderate–severe AP than in those with mild AP at discharge (533 vs. 757 μmol/L, p = 0.023) but not at admission. After adjusting for BMI, multivariable regression indicated that patients with GlycA levels > 400 μmol/L had significantly higher odds of having AP of any severity (OR = 6.88; 95% CI, 2.07–32.2; p = 0.004) and mild AP (OR = 6.12; 95% CI, 1.48–42.0; p = 0.025) than controls. Conclusion: Our pilot study highlights the use of GlycA as a novel diagnostic biomarker of inflammation in patients with AP. Our study shows that GlycA levels were significantly higher in hospitalized AP patients compared to healthy controls. Patients with moderate-to-severe AP had higher GlycA levels compared to patients with mild AP at the time of their hospital discharge, suggesting persistent inflammation in patients with severe disease. Full article
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16 pages, 1601 KiB  
Article
Blood Metabolite Profiling of Antarctic Expedition Members: An 1H NMR Spectroscopy-Based Study
by Laura Del Coco, Marco Greco, Alessandra Inguscio, Anas Munir, Antonio Danieli, Luca Cossa, Debora Musarò, Maria Rosaria Coscia, Francesco Paolo Fanizzi and Michele Maffia
Int. J. Mol. Sci. 2023, 24(9), 8459; https://doi.org/10.3390/ijms24098459 - 8 May 2023
Cited by 3 | Viewed by 3038
Abstract
Serum samples from eight participants during the XV winter-over at Concordia base (Antarctic expedition) collected at defined time points, including predeparture, constituted the key substrates for a specific metabolomics study. To ascertain acute changes and chronic adaptation to hypoxia, the metabolic profiles of [...] Read more.
Serum samples from eight participants during the XV winter-over at Concordia base (Antarctic expedition) collected at defined time points, including predeparture, constituted the key substrates for a specific metabolomics study. To ascertain acute changes and chronic adaptation to hypoxia, the metabolic profiles of the serum samples were analyzed using NMR spectroscopy, with principal components analysis (PCA) followed by partial least squares and orthogonal partial least squares discriminant analyses (PLS-DA and OPLS-DA) used as supervised classification methods. Multivariate data analyses clearly highlighted an adaptation period characterized by an increase in the levels of circulating glutamine and lipids, mobilized to supply the body energy needs. At the same time, a reduction in the circulating levels of glutamate and N-acetyl glycoproteins, stress condition indicators, and proinflammatory markers were also found in the NMR data investigation. Subsequent pathway analysis showed possible perturbations in metabolic processes, potentially related to the physiological adaptation, predominantly found by comparing the baseline (at sea level, before mission onset), the base arrival, and the mission ending collected values. Full article
(This article belongs to the Special Issue Adaptation to Hypoxia: Beyond the Chimera)
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