-
Journal of Reproductive Immunology Jun 2024Abnormal placental angiogenesis during gestation resulting from high levels of anti-angiogenic factors, soluble fms-like tyrosine kinase-1 (sFLT1) and soluble endoglin,...
Abnormal placental angiogenesis during gestation resulting from high levels of anti-angiogenic factors, soluble fms-like tyrosine kinase-1 (sFLT1) and soluble endoglin, has been implicated in the progression of preeclampsia (PE). This heterogeneous syndrome (defined by hypertension with or without proteinuria after 20 weeks of pregnancy) remains a major global health burden with long-term consequences for both mothers and child. Previously, we showed that in vivo systemic human (hsFLT1) overexpression led to reduced placental efficiency and PE-like syndrome in mice. Galectins (gal-1, -3 and -9) are critical determinants of vascular adaptation to pregnancy and dysregulation of the galectin-glycan circuits is associated with the development of this life-threatening disease. In this study, we assessed the galectin-glycan networks at the maternal-fetal interface associated with the hsFLT1-induced PE in mice. We observed an increase on the maternal gal-1 expression in the decidua and junctional zone layers of the placenta derived from hs FLT1 pregnancies. In contrast, placental gal-3 and gal-9 expression were not sensitive to the hsFLT1 overexpression. In addition, O- and N-linked glycan expression, poly-LacNAc sequences and terminal sialylation were down-regulated in hsFLT1 placentas. Thus, the gal-1-glycan axis appear to play an important role counteracting the anti-angiogenic status caused by sFLT1, becoming critical for vascular adaptation at the maternal-fetal interface.
PubMed: 38908337
DOI: 10.1016/j.jri.2024.104284 -
Cell Reports. Medicine Jun 2024Immune checkpoint inhibitors (ICIs) activate anti-cancer immunity by blocking T cell checkpoint molecules such as programmed death 1 (PD-1) and cytotoxic T... (Review)
Review
Immune checkpoint inhibitors (ICIs) activate anti-cancer immunity by blocking T cell checkpoint molecules such as programmed death 1 (PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA-4). Although ICIs induce some durable responses in various cancer patients, they also have disadvantages, including low response rates, the potential for severe side effects, and high treatment costs. Therefore, selection of patients who can benefit from ICI treatment is critical, and identification of biomarkers is essential to improve the efficiency of ICIs. In this review, we provide updated information on established predictive biomarkers (tumor programmed death-ligand 1 [PD-L1] expression, DNA mismatch repair deficiency, microsatellite instability high, and tumor mutational burden) and potential biomarkers currently under investigation such as tumor-infiltrated and peripheral lymphocytes, gut microbiome, and signaling pathways related to DNA damage and antigen presentation. In particular, this review aims to summarize the current knowledge of biomarkers, discuss issues, and further explore future biomarkers.
PubMed: 38906149
DOI: 10.1016/j.xcrm.2024.101621 -
BMC Plant Biology Jun 2024Soapberry (Sapindus mukorossi) is an economically important multifunctional tree species. Triterpenoid saponins have many functions in soapberry. However, the types of...
BACKGROUND
Soapberry (Sapindus mukorossi) is an economically important multifunctional tree species. Triterpenoid saponins have many functions in soapberry. However, the types of uridine diphosphate (UDP) glucosyltransferases (UGTs) involved in the synthesis of triterpenoid saponins in soapberry have not been clarified.
RESULTS
In this study, 42 SmUGTs were identified in soapberry, which were unevenly distributed on 12 chromosomes and had sequence lengths of 450 bp to 1638 bp, with an average of 1388 bp. The number of amino acids in SmUGTs was 149 to 545, with an average of 462. Most SmUGTs were acidic and hydrophilic unstable proteins, and their secondary structures were mainly α-helices and random coils. All had conserved UDPGT and PSPG-box domains. Phylogenetic analysis divided them into four subclasses, which glycosylated different carbon atoms. Prediction of cis-acting elements suggested roles of SmUGTs in plant development and responses to environmental stresses. The expression patterns of SmUGTs differed according to the developmental stage of fruits, as determined by transcriptomics and RT-qPCR. Co-expression network analysis of SmUGTs and related genes/transcription factors in the triterpenoid saponin synthesis pathway was also performed. The results indicated potential roles for many transcription factors, such as SmERFs, SmGATAs and SmMYBs. A correlation analysis showed that 42 SmUGTs were crucial in saponin synthesis in soapberry.
CONCLUSIONS
Our findings suggest optimal targets for manipulating glycosylation in soapberry triterpenoid saponin biosynthesis; they also provide a theoretical foundation for further evaluation of the functions of SmUGTs and analyses of their biosynthetic mechanisms.
Topics: Saponins; Sapindus; Phylogeny; Triterpenes; Glucosyltransferases; Genes, Plant; Plant Proteins; Gene Expression Regulation, Plant
PubMed: 38902602
DOI: 10.1186/s12870-024-05281-4 -
Nature Communications Jun 2024Disrupted glucose metabolism and protein misfolding are key characteristics of age-related neurodegenerative disorders including Parkinson's disease, however their...
Disrupted glucose metabolism and protein misfolding are key characteristics of age-related neurodegenerative disorders including Parkinson's disease, however their mechanistic linkage is largely unexplored. The hexosamine biosynthetic pathway utilizes glucose and uridine-5'-triphosphate to generate N-linked glycans required for protein folding in the endoplasmic reticulum. Here we find that Parkinson's patient midbrain cultures accumulate glucose and uridine-5'-triphosphate, while N-glycan synthesis rates are reduced. Impaired glucose flux occurred by selective reduction of the rate-limiting enzyme, GFPT2, through disrupted signaling between the unfolded protein response and the hexosamine pathway. Failure of the unfolded protein response and reduced N-glycosylation caused immature lysosomal hydrolases to misfold and accumulate, while accelerating glucose flux through the hexosamine pathway rescued hydrolase function and reduced pathological α-synuclein. Our data indicate that the hexosamine pathway integrates glucose metabolism with lysosomal activity, and its failure in Parkinson's disease occurs by uncoupling of the unfolded protein response-hexosamine pathway axis. These findings offer new methods to restore proteostasis by hexosamine pathway enhancement.
Topics: Humans; Hexosamines; Lysosomes; Parkinson Disease; Unfolded Protein Response; Neurons; Induced Pluripotent Stem Cells; Mesencephalon; Glucose; Biosynthetic Pathways; Glycosylation; alpha-Synuclein; Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing)
PubMed: 38897986
DOI: 10.1038/s41467-024-49256-3 -
Current Biology : CB Jun 2024Many bacteria glycosylate flagellin on serine or threonine residues using pseudaminic acid (Pse) or other sialic acid-like donor sugars. Successful reconstitution of...
Many bacteria glycosylate flagellin on serine or threonine residues using pseudaminic acid (Pse) or other sialic acid-like donor sugars. Successful reconstitution of Pse-dependent sialylation by the conserved Maf-type flagellin glycosyltransferase (fGT) may require (a) missing component(s). Here, we characterize both Maf paralogs in the Gram-negative bacterium Shewanella oneidensis MR-1 and reconstitute Pse-dependent glycosylation in heterologous hosts. Remarkably, we uncovered distinct acceptor determinants and target specificities for each Maf. Whereas Maf-1 uses its C-terminal tetratricopeptide repeat (TPR) domain to confer flagellin acceptor and O-glycosylation specificity, Maf-2 requires the newly identified conserved specificity factor, glycosylation factor for Maf (GlfM), to form a ternary complex with flagellin. GlfM orthologs are co-encoded with Maf-2 in Gram-negative and Gram-positive bacteria and require an invariant aspartate in their four-helix bundle to function with Maf-2. Thus, convergent fGT evolution underlies distinct flagellin-binding modes in tripartite versus bipartite systems and, consequently, distinct O-glycosylation preferences of acceptor serine residues with Pse.
PubMed: 38897200
DOI: 10.1016/j.cub.2024.05.058 -
Applied Microbiology and Biotechnology Jun 2024Chinese hamster ovary (CHO) cells are popular in the pharmaceutical industry for their ability to produce high concentrations of antibodies and their resemblance to...
Chinese hamster ovary (CHO) cells are popular in the pharmaceutical industry for their ability to produce high concentrations of antibodies and their resemblance to human cells in terms of protein glycosylation patterns. Current data indicate the relevance of CHO cells in the biopharmaceutical industry, with a high number of product commendations and a significant market share for monoclonal antibodies. To enhance the production capabilities of CHO cells, a deep understanding of their cellular and molecular composition is crucial. Genome sequencing and proteomic analysis have provided valuable insights into the impact of the bioprocessing conditions, productivity, and product quality. In our investigation, we conducted a comparative analysis of proteomic profiles in high and low monoclonal antibody-producing cell lines and studied the impact of tunicamycin (TM)-induced endoplasmic reticulum (ER) stress. We examined the expression levels of different proteins including unfolded protein response (UPR) target genes by using label-free quantification techniques for protein abundance. Our results show the upregulation of proteins associated with protein folding mechanisms in low producer vs. high producer cell line suggesting a form of ER stress related to specific protein production. Further, Hspa9 and Dnaja3 are notable candidates activated by the mitochondria UPR and play important roles in protein folding processes in mitochondria. We identified significant upregulation of Nedd8 and Lgmn proteins in similar levels which may contribute to UPR stress. Interestingly, the downregulation of Hspa5/Bip and Pdia4 in response to tunicamycin treatment suggests a low-level UPR activation. KEY POINTS: • Proteome profiling of recombinant CHO cells under mild TM treatment. • Identified protein clusters are associated with the unfolded protein response (UPR). • The compared cell lines revealed noticeable disparities in protein expression levels.
Topics: CHO Cells; Cricetulus; Tunicamycin; Animals; Antibodies, Monoclonal; Proteomics; Endoplasmic Reticulum Stress; Unfolded Protein Response; Proteome; Cricetinae
PubMed: 38896138
DOI: 10.1007/s00253-024-13223-1 -
BioRxiv : the Preprint Server For... Jun 2024Tuberculosis (TB) is the number one infectious disease cause of death worldwide in part due to an incomplete understanding of immunity. Emerging data highlight antibody...
Tuberculosis (TB) is the number one infectious disease cause of death worldwide in part due to an incomplete understanding of immunity. Emerging data highlight antibody functions as correlates of protection and disease across human TB. However, little is known about how antibody functions impact , the causative agent. Here, we use antigen specificity to understand how antibodies mediate host- interactions. We focus on cell wall and ESAT-6 & CFP-10, critical bacterial structural and secreted virulence proteins. In polyclonal IgG from TB patients, we observe that antigen specificity alters IgG subclass and glycosylation that drives Fc receptor binding and effector functions. Through in vitro models of macrophage infection we find that cell wall IgG3, sialic acid, and fucose increase opsonophagocytosis of extracellular and bacterial burden, suggesting that some polyclonal IgG enhance disease. In contrast, ESAT-6 & CFP-10 IgG1 inhibits intracellular , suggesting that antibodies targeting secreted virulence factors are protective. We test this hypothesis by generating a mAb that reacts to ESAT-6 & CFP-10 and show that it alone inhibits intracellular . Understanding which antigens elicit antibody mediated disease enhancement and or protection will be critical in appreciating the many roles for antibodies in TB.
PubMed: 38895452
DOI: 10.1101/2024.06.03.597169 -
Molecules (Basel, Switzerland) Jun 2024The Omicron BA.5 variant of SARS-CoV-2 is known for its high transmissibility and its capacity to evade immunity provided by vaccine protection against the (original)...
Non-Glycosylated SARS-CoV-2 Omicron BA.5 Receptor Binding Domain (RBD) with a Native-like Conformation Induces a Robust Immune Response with Potent Neutralization in a Mouse Model.
The Omicron BA.5 variant of SARS-CoV-2 is known for its high transmissibility and its capacity to evade immunity provided by vaccine protection against the (original) Wuhan strain. In our prior research, we successfully produced the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein in an expression system. Extensive biophysical characterization indicated that, even without glycosylation, the RBD maintained native-like conformational and biophysical properties. The current study explores the immunogenicity and neutralization capacity of the -expressed Omicron BA.5 RBD using a mouse model. Administration of three doses of the RBD without any adjuvant elicited high titer antisera of up to 7.3 × 10 and up to 1.6 × 10 after a booster shot. Immunization with RBD notably enhanced the population of CD44CD62L T cells, indicating the generation of T cell memory. The in vitro assays demonstrated the antisera's protective efficacy through significant inhibition of the interaction between SARS-CoV-2 and its human receptor, ACE2, and through potent neutralization of a pseudovirus. These findings underscore the potential of our -expressed RBD as a viable vaccine candidate against the Omicron variant of SARS-CoV-2.
Topics: Animals; SARS-CoV-2; Spike Glycoprotein, Coronavirus; Mice; Antibodies, Neutralizing; COVID-19; Angiotensin-Converting Enzyme 2; Humans; COVID-19 Vaccines; Antibodies, Viral; Disease Models, Animal; Protein Domains; Glycosylation; Protein Binding; Female; Escherichia coli; T-Lymphocytes
PubMed: 38893549
DOI: 10.3390/molecules29112676 -
International Journal of Molecular... Jun 2024Post-translational modifications (PTMs) are essential for regulating protein functions, influencing various fundamental processes in eukaryotes. These include, but are... (Review)
Review
Post-translational modifications (PTMs) are essential for regulating protein functions, influencing various fundamental processes in eukaryotes. These include, but are not limited to, cell signaling, protein trafficking, the epigenetic control of gene expression, and control of the cell cycle, as well as cell proliferation, differentiation, and interactions between cells. In this review, we discuss protein PTMs that play a key role in the malaria parasite biology and its pathogenesis. Phosphorylation, acetylation, methylation, lipidation and lipoxidation, glycosylation, ubiquitination and sumoylation, nitrosylation and glutathionylation, all of which occur in malarial parasites, are reviewed. We provide information regarding the biological significance of these modifications along all phases of the complex life cycle of spp. Importantly, not only the parasite, but also the host and vector protein PTMs are often crucial for parasite growth and development. In addition to metabolic regulations, protein PTMs can result in epitopes that are able to elicit both innate and adaptive immune responses of the host or vector. We discuss some existing and prospective results from antimalarial drug discovery trials that target various PTM-related processes in the parasite or host.
Topics: Protein Processing, Post-Translational; Life Cycle Stages; Humans; Animals; Protozoan Proteins; Plasmodium; Malaria; Host-Parasite Interactions
PubMed: 38892332
DOI: 10.3390/ijms25116145 -
International Journal of Molecular... May 2024In our previous study, two oleanane-type pentacyclic triterpenoids (oleanolic acid and maslinic acid) were reported to affect the -glycosylation and intracellular...
Structure-Activity Relationship of Oleanane-Type Pentacyclic Triterpenoids on Nuclear Factor κB Activation and Intracellular Trafficking and -Linked Glycosylation of Intercellular Adhesion Molecule-1.
In our previous study, two oleanane-type pentacyclic triterpenoids (oleanolic acid and maslinic acid) were reported to affect the -glycosylation and intracellular trafficking of intercellular adhesion molecule-1 (ICAM-1). The present study was aimed at investigating the structure-activity relationship of 13 oleanane-type natural triterpenoids with respect to the nuclear factor κB (NF-κB) signaling pathway and the expression, intracellular trafficking, and -glycosylation of the ICAM-1 protein in human lung adenocarcinoma A549 cells. Hederagenin, echinocystic acid, erythrodiol, and maslinic acid, which all possess two hydroxyl groups, decreased the viability of A549 cells. Celastrol and pristimerin, both of which possess an ,-unsaturated carbonyl group, decreased cell viability but more strongly inhibited the interleukin-1α-induced NF-κB signaling pathway. Oleanolic acid, moronic acid, and glycyrrhetinic acid interfered with -glycosylation without affecting the cell surface expression of the ICAM-1 protein. In contrast, -boswellic acid and maslinic acid interfered with the -glycosylation of the ICAM-1 protein, which resulted in the accumulation of high-mannose-type -glycans. Among the oleanane-type triterpenoids tested, -boswellic acid and maslinic acid uniquely interfered with the intracellular trafficking and -glycosylation of glycoproteins.
Topics: Humans; Intercellular Adhesion Molecule-1; Glycosylation; NF-kappa B; Structure-Activity Relationship; Oleanolic Acid; A549 Cells; Protein Transport; Pentacyclic Triterpenes; Triterpenes; Signal Transduction; Cell Survival
PubMed: 38892215
DOI: 10.3390/ijms25116026