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Carbohydrate Research Sep 2023To uncover how cells distinguish between misfolded and correctly-folded glycoproteins, homogeneous misfolded glycoproteins are needed as a probe for analysis of their...
To uncover how cells distinguish between misfolded and correctly-folded glycoproteins, homogeneous misfolded glycoproteins are needed as a probe for analysis of their structure and chemical characteristic nature. In this study, we have synthesized misfolded glycosyl interleukin-8 (IL-8) by combining E. coli expression and chemical synthesis to improve the synthetic efficiency. In order to prepare N-terminal peptide-thioester segment (1-33), we prepared an E. coli expressed peptide and then activated the C-terminal Cys by using an intramolecular N-to-S acyl shift reaction, followed by trans-thioesterification of the Cys-thioester with an external bis(2-sulfanylethyl)amine (SEA). The glycopeptide segment (34-49) was prepared by solid phase peptide synthesis and the C-terminal peptide (50-72) was prepared in E. coli. These peptide and glycopeptide segments were successfully coupled by sequential native chemical ligation. To obtain homogeneous misfolded glycoproteins by shuffling the disulfide bond pattern, folding conditions were optimized to maximize the yield of individual homogeneous misfolded glycoproteins.
Topics: Interleukin-8; Escherichia coli; Peptides; Glycoproteins; Glycopeptides
PubMed: 37354703
DOI: 10.1016/j.carres.2023.108847 -
Journal of Dentistry Sep 2023To identify the metabolomic differences in the saliva of healthy children versus children with active carious lesions and to estimate the predictive capacity of a model...
OBJECTIVES
To identify the metabolomic differences in the saliva of healthy children versus children with active carious lesions and to estimate the predictive capacity of a model based on the salivary metabolomic profile.
METHODS
A study of cases (n = 31) and controls (n = 37) was designed for children aged between 6 and 12 (mean age of the cases: 8.9; controls: 8.7). The said children attended public health centers in Valencia, Spain. Intraoral examinations were performed by a single examiner using ICDAS II diagnostic criteria. Unstimulated total saliva samples were analyzed by nuclear magnetic resonance (NMR) spectroscopy.
RESULTS
The dft index for cases was 2.84 while it was 0.19 for the control group, the DMFT index was 1.13 and 0.11, respectively. The predictive model generated by the multivariate PLS-DA analysis projects a separation between the cases and the controls on the score chart with a predictive capacity and generating an area under the curve of 0.71. The metabolites: 3-methyl-2-oxovalerate, 3-hydroxybutyrate, lactate, acetone, citrate, ornithine, ethanolamine, taurine, proline, glycine, mannose, glucose, 1-6-Anhydro-β-d-glucose and citraconate, are those that show greater significance in the model. In the controls, glycine (Cohen's d = 0.430) and glucose (Cohen's d = 0.560) present higher means compared to the cases. On the contrary, taurine (Cohen's d= -0.474) and mannose (Cohen's d= -0.456) show higher means in cases compared to controls.
CONCLUSIONS
Our findings show a difference in the salivary metabolomic profiles, specifically in the groups of saccharides and amino acids, suggesting an association of these with the level of caries risk.
CLINICAL SIGNIFICANCE
The results reported in the present study reinforce the use of salivary metabolomics as a research method for the search for salivary biomarkers that allow the evaluation of caries risk in patients. Furthermore, it brings us closer to a personalized medicine that will help in dental caries prevention strategies.
Topics: Humans; Child; Dental Caries; Mannose; Saliva; Metabolomics; Glucose; Glycine; Taurine
PubMed: 37524196
DOI: 10.1016/j.jdent.2023.104645 -
Glycobiology Dec 2023Recent research has unveiled numerous important functions of protein glycosylation in development, homeostasis, and diseases. A type of glycosylation taking the center... (Review)
Review
Recent research has unveiled numerous important functions of protein glycosylation in development, homeostasis, and diseases. A type of glycosylation taking the center stage is protein O-mannosylation, a posttranslational modification conserved in a wide range of organisms, from yeast to humans. In animals, protein O-mannosylation plays a crucial role in the nervous system, whereas protein O-mannosylation defects cause severe neurological abnormalities and congenital muscular dystrophies. However, the molecular and cellular mechanisms underlying protein O-mannosylation functions and biosynthesis remain not well understood. This review outlines recent studies on protein O-mannosylation while focusing on the functions in the nervous system, summarizes the current knowledge about protein O-mannosylation biosynthesis, and discusses the pathologies associated with protein O-mannosylation defects. The evolutionary perspective revealed by studies in the Drosophila model system are also highlighted. Finally, the review touches upon important knowledge gaps in the field and discusses critical questions for future research on the molecular and cellular mechanisms associated with protein O-mannosylation functions.
Topics: Animals; Humans; Glycosylation; Sugars; Mannose; Protein Processing, Post-Translational; Drosophila; Saccharomyces cerevisiae; Mannosyltransferases
PubMed: 37565810
DOI: 10.1093/glycob/cwad067 -
European Urology Focus Jul 2023The rise in antimicrobial resistance means that alternative approaches for the treatment and prevention of urinary tract infection (UTIs) are required. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The rise in antimicrobial resistance means that alternative approaches for the treatment and prevention of urinary tract infection (UTIs) are required.
OBJECTIVE
To evaluate the safety and efficacy of a D-mannose-based dietary supplement (D-mannose, citric acid, prebiotic fibers, Astragalus, and dandelion; DAPAD complex) for the treatment of uncomplicated acute E. coli UTIs.
DESIGN, SETTING, AND PARTICIPANTS
This was a single-center, randomized, double-blind, placebo-controlled trial conducted from April 2021 to October 2021 in Rajalakshmi Hospital and Research Centre (Bangalore, India). The participants were nonmenopausal women with an acute uncomplicated E. coli UTI. UTI was diagnosed according to the presence of at least one urinary symptom and bacteriuria (>100 000 CFU/ml).
INTERVENTION
The DAPAD complex was administered twice a day for 5 d, with phenazopyridine and alkalizing agents as the standard of care (SOC). The control group received placebo with SOC.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS
Subjective (clinical resolution/response) and objective (midstream bacteriuria) outcomes were evaluated at the end of therapy (day 6) and at day 35 of follow-up. Adverse events were recorded. Categorical variables were analyzed using χ and Fisher's exact tests; a p value <0.05 was considered significant.
RESULTS AND LIMITATIONS
Seventy women were enrolled and equally randomized to the two groups. Clinical resolution was higher in the DAPAD group at 6 d (34.3% vs 0%; p < 0.0001) and 35 d from baseline (88.6% vs 20%, p < 0.0001). At day 35, no patients in the DAPAD group had moderate or severe symptoms, whereas 25.7% (nine/35) and 11.4% (four/35) of patients in the placebo group had moderate and severe symptoms, respectively. Bacteriological resolution was also higher in the DAPAD group at day 6 (85.7% vs 14.3%; p < 0.0001) and day 35 (100% vs 40%; p < 0.0001). Three mild adverse events (4.26%) unrelated to the investigated product were recorded, all of which were medically treated.
CONCLUSIONS
The DAPAD complex dietary supplement is effective and safe for treatment of acute uncomplicated E. coli UTIs.
PATIENT SUMMARY
Our results show that for nonmenopausal women with an uncomplicated Escherichia coli urinary tract infection, those treated with a dietary supplement (containing D-mannose, citric acid, prebiotic fibers, Astragalus, and dandelion) had a higher rate of clinical resolution or response than women who received a placebo.
Topics: Female; Humans; Mannose; Bacteriuria; Escherichia coli; Treatment Outcome; India; Urinary Tract Infections; Escherichia coli Infections; Dietary Supplements; Prebiotics
PubMed: 36621376
DOI: 10.1016/j.euf.2022.12.013 -
Histology and Histopathology Nov 2023To explore the effects and potential mechanisms of D-mannose on adipogenic differentiation of two kinds of representative mesenchymal stem cells (MSCs).
PURPOSE
To explore the effects and potential mechanisms of D-mannose on adipogenic differentiation of two kinds of representative mesenchymal stem cells (MSCs).
METHODS
We cultured two kinds of representative MSCs, human adipose tissue-derived stromal cells (hADSCs) as well as human bone marrow mesenchymal stem cells (hBMSCs), with adipogenic-induced medium containing D-mannose or D-fructose as the control. Oil red O staining, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot (WB) were used to detect whether D-mannose had effects on adipogenic differentiation of MSCs. RNA sequencing (RNA-seq) transcriptomic analysis was further used to explore the potential mechanisms of D-mannose on adipogenic differentiation of MSCs. After that, qRT-PCR and WB were used to verify the results of RNA-seq. Last, we removed bilateral ovaries of female rats to establish an estrogen deficiency obesity model, and gave D-mannose intragastric administration. One month later, the femurs of rats were sliced for oil red O staining, and the inhibitory effect of D-mannose on lipid formation in vivo was studied.
RESULTS
Oil red O staining, qRT-PCR and WB in vitro demonstrated that D-mannose inhibited the adipogenic differentiation of both hADSCs and hBMSCs. Oil red O staining of femur sections proved that D-mannose was able to reduce in vivo adipogenesis. The results of RNA-seq transcriptomic analysis revealed that the adipogenesis-inhibition effects of D-mannose were performed by antagonizing the PI3K/AKT signaling pathway. Besides, qRT-PCR and WB further verified the results of RNA-seq.
CONCLUSION
Our study indicated that D-mannose was able to reduce adipogenic differentiation of both hADSCs and hBMSCs by antagonizing the PI3K/AKT signaling pathway. D-mannose is expected to be a safe and effective treatment strategy for obesity.
Topics: Female; Humans; Rats; Animals; Adipogenesis; Proto-Oncogene Proteins c-akt; Phosphatidylinositol 3-Kinases; Mannose; Cells, Cultured; Signal Transduction; Cell Differentiation; Obesity; Osteogenesis
PubMed: 37246829
DOI: 10.14670/HH-18-631 -
Developmental Cell Jan 2024Aging is a risk factor for disease via increased susceptibility to infection, decreased ability to maintain homeostasis, inefficiency in combating stress, and decreased...
Aging is a risk factor for disease via increased susceptibility to infection, decreased ability to maintain homeostasis, inefficiency in combating stress, and decreased regenerative capacity. Multiple diseases, including urinary tract infection (UTI), are more prevalent with age; however, the mechanisms underlying the impact of aging on the urinary tract mucosa and the correlation between aging and disease remain poorly understood. Here, we show that, relative to young (8-12 weeks) mice, the urothelium of aged (18-24 months) female mice accumulates large lysosomes with reduced acid phosphatase activity and decreased overall autophagic flux in the aged urothelium, indicative of compromised cellular homeostasis. Aged bladders also exhibit basal accumulation of reactive oxygen species (ROS) and a dampened redox response, implying heightened oxidative stress. Furthermore, we identify a canonical senescence-associated secretory phenotype (SASP) in the aged urothelium, along with continuous NLRP3-inflammasome- and Gasdermin-D-dependent pyroptotic cell death. Consequently, aged mice chronically exfoliate urothelial cells, further exacerbating age-related urothelial dysfunction. Upon infection with uropathogenic E. coli, aged mice harbor increased bacterial reservoirs and are more prone to spontaneous recurrent UTI. Finally, we discover that treatment with D-mannose, a natural bioactive monosaccharide, rescues autophagy flux, reverses the SASP, and mitigates ROS and NLRP3/Gasdermin/interleukin (IL)-1β-driven pyroptotic epithelial cell shedding in aged mice. Collectively, our results demonstrate that normal aging affects bladder physiology, with aging alone increasing baseline cellular stress and susceptibility to infection, and suggest that mannose supplementation could serve as a senotherapeutic to counter age-associated urothelial dysfunction.
Topics: Mice; Female; Animals; NLR Family, Pyrin Domain-Containing 3 Protein; Urinary Bladder; Mannose; Reactive Oxygen Species; Escherichia coli; Urothelium; Interleukin-1beta; Gasdermins; Urinary Tract Infections; Cellular Senescence
PubMed: 38101412
DOI: 10.1016/j.devcel.2023.11.017 -
International Journal of Biological... Dec 2023Crataegus, is a genus within the Rosaceae family. It is recognized as a valuable plant with both medicinal and edible qualities, earning it the epithet of the... (Review)
Review
Crataegus, is a genus within the Rosaceae family. It is recognized as a valuable plant with both medicinal and edible qualities, earning it the epithet of the "nutritious fruit" owing to its abundant bioactive compounds. Polysaccharides are carbohydrate polymers linked by glycosidic bonds, one of the crucial bioactive ingredients of Crataegus spp. Recently, Crataegus spp. polysaccharides (CPs) have garnered considerable attention due to their diverse range of bioactivities, including prebiotic, hypolipidemic, anticancer, antibacterial, antioxidant, and immunobiological properties. Herein, we provide a comprehensive overview of recent research on CPs. The analysis revealed that CPs exhibited a broad molecular weight distribution, ranging from 5.70 Da to 4.76 × 10 Da, and are composed of various monosaccharide constituents such as mannose, rhamnose, and arabinose. Structure-activity relationships demonstrated that the biological function of CPs is closely associated with their molecular weight, galacturonic acid content, and chemical modifications. Additionally, CPs have excellent bioavailability, biocompatibility, and biodegradability, which make them promising candidates for applications in the food, medicine, and cosmetic industries. The article also scrutinized the potential development and future research directions of CPs. Overall, this article provides comprehensive knowledge and underpinnings of CPs for future research and development as therapeutic agents and multifunctional food additives.
Topics: Crataegus; Polysaccharides; Monosaccharides; Molecular Weight; Mannose; Antioxidants
PubMed: 37689285
DOI: 10.1016/j.ijbiomac.2023.126671 -
Glycoconjugate Journal Feb 2024Lectins are non-immunological carbohydrate-binding proteins classified on the basis of their structure, origin, and sugar specificity. The binding specificity of such... (Review)
Review
Lectins are non-immunological carbohydrate-binding proteins classified on the basis of their structure, origin, and sugar specificity. The binding specificity of such proteins with the surface glycan moiety determines their activity and clinical applications. Thus, lectins hold great potential as diagnostic and drug discovery agents and as novel biopharmaceutical products. In recent years, significant advancements have been made in understanding plant and microbial lectins as therapeutic agents against various viral diseases. Among them, mannose-specific lectins have being proven as promising antiviral agents against a variety of viruses, such as HIV, Influenza, Herpes, Ebola, Hepatitis, Severe Acute Respiratory Syndrome Coronavirus-1 (SARS-CoV-1), Middle Eastern Respiratory Syndrome Coronavirus (MERS-CoV) and most recent Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The binding of mannose-binding lectins (MBLs) from plants and microbes to high-mannose containing N-glycans (which may be simple or complex) of glycoproteins found on the surface of viruses has been found to be highly specific and mainly responsible for their antiviral activity. MBLs target various steps in the viral life cycle, including viral attachment, entry and replication. The present review discusses the brief classification and structure of lectins along with antiviral activity of various mannose-specific lectins from plants and microbial sources and their diagnostic and therapeutic applications against viral diseases.
Topics: Humans; Lectins; Mannose; Glycoproteins; SARS-CoV-2; Polysaccharides; Antiviral Agents; Virus Diseases; Plant Lectins; Mannose-Binding Lectins
PubMed: 38244136
DOI: 10.1007/s10719-023-10142-7 -
Chemistry (Weinheim An Der Bergstrasse,... May 2024C-type lectins are a large superfamily of proteins involved in a multitude of biological processes. In particular, their involvement in immunity and homeostasis has... (Review)
Review
C-type lectins are a large superfamily of proteins involved in a multitude of biological processes. In particular, their involvement in immunity and homeostasis has rendered them attractive targets for diverse therapeutic interventions. They share a characteristic C-type lectin-like domain whose adaptability enables them to bind a broad spectrum of ligands beyond the originally defined canonical Ca-dependent carbohydrate binding. Together with variable domain architecture and high-level conformational plasticity, this enables C-type lectins to meet diverse functional demands. Secondary sites provide another layer of regulation and are often intricately linked to functional diversity. Located remote from the canonical primary binding site, secondary sites can accommodate ligands with other physicochemical properties and alter protein dynamics, thus enhancing selectivity and enabling fine-tuning of the biological response. In this review, we outline the structural determinants allowing C-type lectins to perform a large variety of tasks and to accommodate the ligands associated with it. Using the six well-characterized Ca-dependent and Ca-independent C-type lectin receptors DC-SIGN, langerin, MGL, dectin-1, CLEC-2 and NKG2D as examples, we focus on the characteristics of non-canonical interactions and secondary sites and their potential use in drug discovery endeavors.
Topics: Lectins, C-Type; Humans; Ligands; Binding Sites; Calcium; Receptors, Cell Surface; Cell Adhesion Molecules; Protein Binding; Mannose-Binding Lectins; Mannose-Binding Lectin; NK Cell Lectin-Like Receptor Subfamily K; Antigens, CD
PubMed: 38527187
DOI: 10.1002/chem.202400660 -
Biochemical and Biophysical Research... Jun 2024Non-alcoholic fatty liver disease (NAFLD), a chronic liver condition and metabolic disorder, has emerged as a significant health issue worldwide. D-mannose, a natural...
Non-alcoholic fatty liver disease (NAFLD), a chronic liver condition and metabolic disorder, has emerged as a significant health issue worldwide. D-mannose, a natural monosaccharide widely existing in plants and animals, has demonstrated metabolic regulatory properties. However, the effect and mechanism by which D-mannose may counteract NAFLD have not been studied. In this study, network pharmacology followed by molecular docking analysis was utilized to identify potential targets of mannose against NAFLD, and the leptin receptor-deficient, genetically obese db/db mice was employed as an animal model of NAFLD to validate the regulation of D-mannose on core targets. As a result, 67 targets of mannose are predicted associated with NAFLD, which are surprisingly centered on the mechanistic target of rapamycin (mTOR). Further analyses suggest that mTOR signaling is functionally enriched in potential targets of mannose treating NAFLD, and that mannose putatively binds to mTOR as a core mechanism. Expectedly, repeated oral gavage of supraphysiological D-mannose ameliorates liver steatosis of db/db mice, which is based on suppression of hepatic mTOR signaling. Moreover, daily D-mannose administration reduced hepatic expression of lipogenic regulatory genes in counteracting NAFLD. Together, these findings reveal D-mannose as an effective and potential NAFLD therapeutic through mTOR suppression, which holds translational promise.
Topics: Animals; Mice; Liver; Mannose; Mice, Inbred C57BL; Molecular Docking Simulation; Network Pharmacology; Non-alcoholic Fatty Liver Disease; Signal Transduction; TOR Serine-Threonine Kinases
PubMed: 38678787
DOI: 10.1016/j.bbrc.2024.149999