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Mediators of Inflammation 2023Vitronectin (VTN) has been reported to trigger cell pyroptosis to aggravate inflammation in our previous study. However, the function of VTN in inflammatory bowel...
OBJECTIVE
Vitronectin (VTN) has been reported to trigger cell pyroptosis to aggravate inflammation in our previous study. However, the function of VTN in inflammatory bowel disease (IBD) remains to be addressed.
METHODS
Real-time PCR and western blotting were performed to analyze VTN-regulated intestinal epithelial cell (IEC) differentiation through ferroptosis, and immunofluorescence (IF), luciferase, and chromatin immunoprecipitation were used to identify whether VTN-modulated ferroptosis is dependent on phosphodiesterase 4 (PDE4)/protein kinase A (PKA)/cyclic adenosine monophosphate-response element-binding protein (CREB) cascade pathway. experiment in mice and a pilot study in patients with IBD were used to confirm inhibition of PDE4-alleviated IECs ferroptosis, leading to cell differentiation during mucosal healing.
RESULTS
Herein, we found that caudal-related homeobox transcription factor 2-mediated IECs differentiation was impaired in response to VTN, which was attributed to enhanced ferroptosis characterized by decreased glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 expression. Inhibition of ferroptosis in IECs rescued the inhibitory effect of VTN on cell differentiation. Further analysis showed that VTN triggered phosphorylation of PDE4, leading to inhibit PKA/CREB activation and CREB nuclear translocation, which further reduced GPX4 transactivation. Endogenous PKA interacted with CREB, and this interaction was destroyed in response to VTN stimulation. What is more, overexpression of CREB in CaCO cells overcame the promotion of VTN on ferroptosis. Most importantly, inhibition of PDE4 by roflumilast or dipyridamole could alleviate dextran sulfate sodium-induced colitis in mice and in a pilot clinical study confirmed by IF.
CONCLUSIONS
These findings demonstrated that highly expressed VTN disrupted IECs differentiation through PDE4-mediated ferroptosis in IBD, suggesting targeting PDE4 could be a promising therapeutic strategy for patients with IBD.
Topics: Mice; Animals; Vitronectin; Cyclic Nucleotide Phosphodiesterases, Type 4; Ferroptosis; Pilot Projects; Inflammatory Bowel Diseases; Cell Differentiation
PubMed: 37501933
DOI: 10.1155/2023/6623329 -
Molecular & Cellular Proteomics : MCP Sep 2023The asialoglycoprotein receptor (ASGPR) and the mannose receptor C-type 1 (MRC1) are well known for their selective recognition and clearance of circulating...
The asialoglycoprotein receptor (ASGPR) and the mannose receptor C-type 1 (MRC1) are well known for their selective recognition and clearance of circulating glycoproteins. Terminal galactose and N-Acetylgalactosamine are recognized by ASGPR, while terminal mannose, fucose, and N-Acetylglucosamine are recognized by MRC1. The effects of ASGPR and MRC1 deficiency on the N-glycosylation of individual circulating proteins have been studied. However, the impact on the homeostasis of the major plasma glycoproteins is debated and their glycosylation has not been mapped with high molecular resolution in this context. Therefore, we evaluated the total plasma N-glycome and plasma proteome of ASGR1 and MRC1 deficient mice. ASGPR deficiency resulted in an increase in O-acetylation of sialic acids accompanied by higher levels of apolipoprotein D, haptoglobin, and vitronectin. MRC1 deficiency decreased fucosylation without affecting the abundance of the major circulating glycoproteins. Our findings confirm that concentrations and N-glycosylation of the major plasma proteins are tightly controlled and further suggest that glycan-binding receptors have redundancy, allowing compensation for the loss of one major clearance receptor.
Topics: Mice; Animals; Asialoglycoprotein Receptor; Mannose Receptor; Glycoproteins; Glycosylation; Protein Processing, Post-Translational; Carrier Proteins; Mannose
PubMed: 37414249
DOI: 10.1016/j.mcpro.2023.100615 -
Virulence Dec 2023is an important bacterial pathogen in poultry. Pathogenic bacteria recruit host complement factors to resist the bactericidal effect of serum complement. Vitronectin...
is an important bacterial pathogen in poultry. Pathogenic bacteria recruit host complement factors to resist the bactericidal effect of serum complement. Vitronectin (Vn) is a complementary regulatory protein that inhibits the formation of the membrane attack complex (MAC). Microbes use outer membrane proteins (OMPs) to hijack Vn for complement evasion. However, the mechanism by which achieves evasion is unclear. This study aimed to characterise OMPs of which interact with duck Vn (dVn) during complement evasion. Far-western assays and comparison of wild-type and mutant strains that were treated with dVn and duck serum demonstrated particularly strong binding of OMP76 to dVn. These data were confirmed with strains expressing and not expressing OMP76. Combining tertiary structure analysis and homology modelling, truncated and knocked-out fragments of OMP76 showed that a cluster of critical amino acids in an extracellular loop of OMP76 mediate the interaction with dVn. Moreover, binding of dVn to inhibited MAC deposition on the bacterial surface thereby enhancing survival in duck serum. Virulence of the mutant strain ΔOMP76 was attenuated significantly relative to the wild-type strain. Furthermore, adhesion and invasion abilities of ΔOMP76 decreased, and histopathological changes showed that ΔOMP76 was less virulent in ducklings. Thus, OMP76 is a key virulence factor of . The identification of OMP76-mediated evasion of complement by recruitment of dVn contributes significantly to the understanding of the molecular mechanism by which escapes host innate immunity and provides a new target for the development of subunit vaccines.
Topics: Animals; Virulence; Ducks; Membrane Proteins; Vitronectin; Bacterial Proteins; Flavobacteriaceae Infections; Immunologic Factors; Complement System Proteins; Poultry Diseases
PubMed: 37326479
DOI: 10.1080/21505594.2023.2223060 -
Yeast (Chichester, England) Aug 2023One of the initial steps necessary for the development of Candida infections is the adherence to the host tissues and cells. Recent transcriptomic studies suggest that,...
One of the initial steps necessary for the development of Candida infections is the adherence to the host tissues and cells. Recent transcriptomic studies suggest that, in Candida parapsilosis-a fungal infectious agent that causes systemic candidiasis in immunosuppressed individuals-the adhesion is mediated by pathogen cell-exposed proteins belonging to the agglutinin-like sequence (Als) family. However, to date, the actual interactions of individual members of this family with human cells and extracellular matrix (ECM) have not been characterized in detail. In the current study, we focused attention on two of these C. parapsilosis Als proteins-CPAR2_404800 and CPAR2_404780-that were proteomically identified in the fungal cell wall of yeasts grown in the media suitable for culturing human epithelial and endothelial cells. Both proteins were extracted from the cell wall and purified, and using a microplate binding assay and a fluorescence microscopic analysis were shown to adhere to human cells of A431 (epithelial) and HMEC-1 (endothelial) lines. The human extracellular matrix components that are also plasma proteins-fibronectin and vitronectin-enhanced these interactions, and also could directly bind to CPAR2_404800 and CPAR2_404780 proteins, with a high affinity (K in a range of 10 to 10 M) as determined by surface plasmon resonance measurements. Our findings highlight the role of proteins CPAR2_404800 and CPAR2_404780 in adhesion to host cells and proteins, contributing to the knowledge of the mechanisms of host-pathogen interactions during C. parapsilosis-caused infections.
Topics: Humans; Candida parapsilosis; Extracellular Matrix Proteins; Fungal Proteins; Endothelial Cells; Cell Wall
PubMed: 36851809
DOI: 10.1002/yea.3847