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ACS Bio & Med Chem Au Jun 2024Carbohydrate recognition is imperative for the induction of sperm acrosomal exocytosis (AE), an essential phenomenon in mammalian fertilization. In mouse sperm,...
Carbohydrate recognition is imperative for the induction of sperm acrosomal exocytosis (AE), an essential phenomenon in mammalian fertilization. In mouse sperm, polynorbornene 100-mers displaying fucose or mannose moieties were effective at inducing AE. In contrast, glycopolymers exhibiting glucose sugars resulted in no AE activation. To further elucidate the role of ligand density on the activation of AE in mouse sperm, a triple-stain flow cytometry assay was employed to determine the efficacy of polynorbornene block copolymers with barbell-like sequences as initiators of AE. Triblock (ABA or ABC) copolymers were synthesized by ring-opening metathesis polymerization (ROMP) with one or two activating sugars, mannose or fucose, and one nonactivating sugar, glucose. The active ligand fractions in the polymers varied from 10, 20, or 40%. Simultaneously, random copolymers comprising 20% activating ligands were prepared to confirm the importance of ligand positionality in AE activation in mouse sperm. Polynorbornene 100-mers possessing two 10-mer blocks of activating sugars were the most effective copolymers at inducing AE with levels of AE comparable to their homopolymer counterparts and more effective than their random analogues. Small-angle X-ray scattering (SAXS) was then performed to verify that there were no differences in the conformations of the glycopolymers contributing to their varying AE activity. SAXS data analysis confirmed that all of the glycopolymers assumed semiflexible cylindrical structures with similar radii and Kuhn lengths. These findings suggest that the overall ligand density of the sugar moieties in the polymer is less important than the positionality of short blocks of high-density ligands for AE activation in mouse sperm.
PubMed: 38911911
DOI: 10.1021/acsbiomedchemau.4c00012 -
Frontiers in Immunology 2024Complement activation is considered to contribute to the pathogenesis of severe SARS-CoV-2 infection, mainly by generating potent immune effector mechanisms including a...
Complement activation is considered to contribute to the pathogenesis of severe SARS-CoV-2 infection, mainly by generating potent immune effector mechanisms including a strong inflammatory response. Involvement of the lectin complement pathway, a major actor of the innate immune anti-viral defense, has been reported previously. It is initiated by recognition of the viral surface Spike glycoprotein by mannose-binding lectin (MBL), which induces activation of the MBL-associated protease MASP-2 and triggers the proteolytic complement cascade. A role for the viral nucleoprotein (N) has also been reported, through binding to MASP-2, leading to protease overactivation and potentiation of the lectin pathway. In the present study, we reinvestigated the interactions of the SARS-CoV-2 N protein, produced either in bacteria or secreted by mammalian cells, with full-length MASP-2 or its catalytic domain, in either active or proenzyme form. We could not confirm the interaction of the N protein with the catalytic domain of MASP-2 but observed N protein binding to proenzyme MASP-2. We did not find a role of the N protein in MBL-mediated activation of the lectin pathway. Finally, we showed that incubation of the N protein with MASP-2 results in proteolysis of the viral protein, an observation that requires further investigation to understand a potential functional significance in infected patients.
Topics: Mannose-Binding Protein-Associated Serine Proteases; Humans; SARS-CoV-2; Complement Pathway, Mannose-Binding Lectin; COVID-19; Protein Binding; Coronavirus Nucleocapsid Proteins; Complement Activation; Mannose-Binding Lectin; Phosphoproteins
PubMed: 38911852
DOI: 10.3389/fimmu.2024.1419165 -
ACS Omega Jun 2024Mushroom polysaccharides are important bioactive compounds derived from mushrooms with various beneficial properties. In this study, the chemical characterization and...
Mushroom polysaccharides are important bioactive compounds derived from mushrooms with various beneficial properties. In this study, the chemical characterization and bioactivities of polysaccharide extracts from four different edible mushrooms, Donk, (Fr.) Quél., (Fr.) Fr., and (Scop.) Singer were studied. Glucose (13.24-56.02%), galactose (14.18-64.05%), mannose (2.18-18.13%), fucose (1.21-5.78%), and arabinose (0.04-5.43%) were identified in all polysaccharide extracts by GC-MS (gas chromatography-mass spectrometry). FT-IR (Fourier transform infrared spectroscopy) confirmed the presence of characteristic carbohydrate patterns. H NMR suggested that all polysaccharide extracts had α- and β-d-mannopyranose, d-glucopyranose, d-galactopyranose, α-l-arabinofuranose, and α-l-fucopyranose residues. Approximate molecular weights of polysaccharide extracts were determined by HPLC (high-performance liquid chromatography). The best antioxidant activity was found in polysaccharide extract in DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging (39.03% at 800 μg/mL), CUPRAC (cupric reducing antioxidant capacity) (A: 387.50 μg/mL), and PRAP (phosphomolybdenum reducing antioxidant power) (A: 384.08 μg/mL) assays. polysaccharide extract showed the highest antioxidant activity in ABTS scavenging (IC: 734.09 μg/mL), β-carotene-linoleic acid (IC: 472.16 μg/mL), and iron chelating (IC: 180.35 μg/mL) assays. Significant anticancer activity was found in polysaccharide extract on HT-29 (IC: 46.49 μg/mL) and HepG2 (IC: 48.50 μg/mL) cell lines and polysaccharide extract on the HeLa cell line (IC: 51.64 μg/mL). Also, polysaccharide extract possessed prominent AChE (acetylcholinesterase) inhibition activity (49.14% at 200 μg/mL).
PubMed: 38911755
DOI: 10.1021/acsomega.4c00322 -
BMC Pediatrics Jun 2024Serum Sickness-Like Reaction (SSLR) is an immune response characterized by rash, polyarthralgias, inflammation, and fever. Serum sickness-like reaction is commonly...
BACKGROUND
Serum Sickness-Like Reaction (SSLR) is an immune response characterized by rash, polyarthralgias, inflammation, and fever. Serum sickness-like reaction is commonly attributed to antibiotics, anticonvulsants, and anti-inflammatory agents.
CASE PRESENTATION
A 16-year-old female with a history of overactive bladder and anemia presented with a diffuse urticarial rash, headaches, joint pain, and swelling for three days. Her medications included oral contraceptive pills, iron, mirabegron, UQora, and a probiotic. Physical examination revealed a diffuse urticarial rash, and her musculoskeletal exam revealed swelling and tenderness in her wrists. She was evaluated by her pediatrician and started on a 7-day course of prednisone, as well as antihistamines. Her CBC, basic metabolic panel, liver function panel, Lyme titers, and urinalysis were all within normal limits. With concern for hypersensitivity reaction to medication, all medications were discontinued. Nine days after symptom onset, the patient was evaluated by an allergist, who confirmed her presentation was consistent with serum sickness-like reaction. Her symptoms resolved, and her medications were re-introduced sequentially over several months. Restarting UQora, however, triggered a recurrence of her symptoms, and it was identified as the culprit medication. Consequently, UQora was permanently discontinued, and the patient has remained symptom-free.
CONCLUSIONS
This case report describes the first documented case of serum sickness-like reaction caused by UQora (active ingredient D-mannose). D-mannose is a monosaccharide, and it is frequently promoted to prevent urinary tract infections. While the clinical features and timeline in this case were typical of serum sickness-like reaction, UQora as the trigger was highly unusual. Clinicians should be aware of the diverse triggers of serum sickness-like reaction and the importance of prompt identification and management to enhance patient safety. Further research is necessary to better understand the potential therapeutic applications of D-mannose, as well as the potential risks and interactions.
Topics: Humans; Female; Serum Sickness; Adolescent
PubMed: 38909179
DOI: 10.1186/s12887-024-04753-8 -
BMC Infectious Diseases Jun 2024Spinal tuberculosis (STB) is a local manifestation of systemic infection caused by Mycobacterium tuberculosis, accounting for a significant proportion of joint...
BACKGROUND
Spinal tuberculosis (STB) is a local manifestation of systemic infection caused by Mycobacterium tuberculosis, accounting for a significant proportion of joint tuberculosis cases. This study aimed to explore the diagnostic value of MRI combined with mannose-binding lectin (MBL) for STB.
METHODS
124 patients suspected of having STB were collected and divided into STB and non-STB groups according to their pathological diagnosis. Serum MBL levels were measured using ELISA and a Pearson analysis was constructed to determine the correlation between MBL and STB. ROC was plotted to analyze their diagnostic value for STB. All the subjects included in the study underwent an MRI.
RESULTS
The sensitivity of MRI for the diagnosis of STB was 84.38% and specificity was 86.67%. The serum MBL levels of the patients in the STB group were significantly lower than the levels in the non-STB group. ROC analysis results indicated that serum MBL's area under the curve (AUC) for diagnosis of STB was 0.836, with a sensitivity of 82.3% and a specificity was 77.4%. The sensitivity of MRI combined with MBL diagnosis was 96.61%, and the specificity was 92.31%, indicating that combining the two diagnostic methods was more effective than using either one alone.
CONCLUSIONS
Both MRI and MBL had certain diagnostic values for STB, but their combined use resulted in a diagnostic accuracy than either one alone.
Topics: Humans; Male; Female; Magnetic Resonance Imaging; Mannose-Binding Lectin; Adult; Middle Aged; Tuberculosis, Spinal; Sensitivity and Specificity; ROC Curve; Aged; Young Adult; Mycobacterium tuberculosis; Clinical Relevance
PubMed: 38907240
DOI: 10.1186/s12879-024-09462-2 -
Free Radical Biology & Medicine Jun 2024Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is intricately involved in modulating the inflammatory response in acute lung injury (ALI) and acute...
BACKGROUND
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is intricately involved in modulating the inflammatory response in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Nevertheless, the myeloid PTEN governing Hippo-YAP pathway mediated oxidative stress and inflammation in lipopolysaccharide (LPS)-induced ALI remains to be elucidate.
METHODS
The floxed Pten (Pten) and myeloid-specific Pten knockout (Pten) mice were intratracheal instill LPS (5 mg/kg) to establish ALI, then Yap siRNA mix with the mannose-conjugated polymers was used to knockdown endogenous macrophage YAP in some Pten mice before LPS challenged. The bone marrow-derived macrophages (BMMs) from Pten and Pten mice were obtained, and BMMs were transfected with CRISPR/Cas9-mediated glycogen synthase kinase 3 Beta (GSK3β) knockout (KO) or Yes-associated protein (YAP) KO vector subjected to LPS (100 ng/ml) challenged or then cocultured with MLE12 cells.
RESULTS
Here, our findings demonstrate that myeloid-specific PTEN deficiency exerts a protective against LPS-induced oxidative stress and inflammation dysregulated in ALI model. Moreover, ablation of the PTEN-YAP axis in macrophages results in reduced nuclear factor-E2-related factor-2 (NRF2) expression, a decrease in antioxidant gene expression, augmented levels of free radicals, lipid and protein peroxidation, heightened generation of pro-inflammatory cytokines, ultimately leading to increased apoptosis in MLE12 cells. Mechanistically, it is noteworthy that the deletion of myeloid PTEN promotes YAP translocation and regulates NRF2 expression, alleviating LPS-induced ALI via the inhibition of GSK3β and MST1 binding.
CONCLUSIONS
Our study underscores the crucial role of the myeloid PTEN-YAP-NRF2 axis in governing oxidative stress and inflammation dysregulated in ALI, indicating its potential as a therapeutic target for ALI.
PubMed: 38901501
DOI: 10.1016/j.freeradbiomed.2024.06.016 -
Journal of Nanobiotechnology Jun 2024Tumor-associated macrophages (TAMs) are a promising target for cancer immunotherapy, but delivering therapeutic agents to TAMs within the tumor microenvironment (TME) is...
Tumor-associated macrophages (TAMs) are a promising target for cancer immunotherapy, but delivering therapeutic agents to TAMs within the tumor microenvironment (TME) is challenging. In this study, a photosensitive, dual-targeting nanoparticle system (M.RGD@Cr-CTS-siYTHDF1 NPs) was developed. The structure includes a shell of DSPE-modified RGD peptides targeting integrin receptors on tumor cells and carboxymethyl mannose targeting CD206 receptors on macrophages, with a core of chitosan adsorbing m6A reading protein YTHDF1 siRNA and chromium nanoparticles (Cr NPs). The approach is specifically designed to target TAM and cancer cells, utilizing the photothermal effect of Cr NPs to disrupt the TME and deliver siYTHDF1 to TAM. In experiments with tumor-bearing mice, M.RGD@Cr-CTS-siYTHDF1 NPs, when exposed to laser irradiation, effectively killed tumor cells, disrupted the TME, delivered siYTHDF1 to TAMs, silenced the YTHDF1 gene, and shifted the STAT3-STAT1 equilibrium by reducing STAT3 and enhancing STAT1 expression. This reprogramming of TAMs towards an anti-tumor phenotype led to a pro-immunogenic TME state. The strategy also suppressed immunosuppressive IL-10 production, increased expression of immunostimulatory factors (IL-12 and IFN-γ), boosted CD8 + T cell infiltration and M1-type TAMs, and reduced Tregs and M2-type TAMs within the TME. In conclusion, the dual-targeting M.RGD@Cr-CTS-siYTHDF1 NPs, integrating dual-targeting capabilities with photothermal therapy (PTT) and RNA interference, offer a promising approach for molecular targeted cancer immunotherapy with potential for clinical application.
Topics: Animals; Mice; Immunotherapy; RNA, Small Interfering; Humans; Liver Neoplasms; Cell Line, Tumor; Tumor Microenvironment; Tumor-Associated Macrophages; RNA-Binding Proteins; Nanoparticles; Metal Nanoparticles; Photosensitizing Agents
PubMed: 38898486
DOI: 10.1186/s12951-024-02612-3 -
Vaccine Jun 2024Subunit vaccines require an immunostimulant (adjuvant) and/or delivery system to induce immunity. However, currently, available adjuvants are either too dangerous in...
Subunit vaccines require an immunostimulant (adjuvant) and/or delivery system to induce immunity. However, currently, available adjuvants are either too dangerous in terms of side effects for human use (experimental adjuvants) or have limited efficacy and applicability. In this study, we examined the capacity of mannose-lipopeptide ligands to enhance the immunogenicity of a vaccine consisting of polyleucine(L)-antigen conjugates anchored to liposomes. The clinically tested Group A Streptococcus (GAS) B-cell epitope, J8, combined with universal T helper PADRE (P) was used as the antigen. Six distinct mannose ligands were incorporated into neutral liposomes carrying LPJ8. While induced antibody titers were relatively low, the ligand carrying mannose, glycine/lysine spacer, and two palmitic acids as liposomal membrane anchoring moieties (ligand 3), induced significantly higher IgG titers than non-mannosylated liposomes. The IgG titers were significantly enhanced when positively charged liposomes were employed. Importantly, the produced antibodies were able to kill GAS bacteria. Unexpectedly, the physical mixture of only ligand 3 and PJ8 produced self-assembled nanorods that induced antibody titers as high as those elicited by the lead liposomal formulation and antigen adjuvanted with the potent, but toxic, complete Freund's adjuvant (CFA). Antibodies produced upon immunization with PJ8 + 3 were even more opsonic than those induced by CFA + PJ8. Importantly, in contrast to CFA, ligand 3 did not induce observable adverse reactions or excessive inflammatory responses. Thus, we demonstrated that a mannose ligand, alone, can serve as an effective vaccine nanoadjuvant.
PubMed: 38897890
DOI: 10.1016/j.vaccine.2024.06.027 -
BioRxiv : the Preprint Server For... Jun 2024The retromer complex mediates retrograde transport of protein cargos from endosomes to the trans-Golgi network (TGN). γ-secretase is a multisubunit protease that...
The retromer complex mediates retrograde transport of protein cargos from endosomes to the trans-Golgi network (TGN). γ-secretase is a multisubunit protease that cleaves the transmembrane domain of its target proteins. Mutations in genes encoding subunits of retromer or γ-secretase can cause familial Alzheimer disease (AD) and other degenerative neurological diseases. It has been reported that retromer interacts with γ-secretase, but the consequences of this interaction are not known. Here, we report that retromer-mediated retrograde protein trafficking in cultured human epithelial cells is impaired by inhibition of γ-secretase activity or by genetic elimination of γ-secretase. γ-secretase inhibitor XXI and knockout of PS1, the catalytic subunit of γ-secretase, inhibit endosome to TGN trafficking of retromer-dependent retrograde cargos, divalent metal transporter 1 isoform II (DMT1-II), cation-independent mannose-6-phosphate receptor (CIMPR), and shiga toxin. Trafficking of retromer-independent cargos, such as cholera toxin and a CIMPR mutant that does not bind to retromer was not affected by γ-secretase inhibition. XXI treatment and PS1 KO inhibit interaction of γ-secretase with retromer but do not inhibit the association of cargo with retromer or with γ-secretase in intact cells. Similarly, these treatments do not affect the level of Rab7-GTP, which regulates retromer-cargo interaction. These results suggest that the γ-secretase-retromer interaction facilitates retromer-mediated retrograde trafficking.
PubMed: 38895404
DOI: 10.1101/2024.06.07.597932 -
Frontiers in Immunology 2024The complement system, an important part of the innate system, is known to play a central role in many immune mediated kidney diseases. All parts of the complement... (Review)
Review
The complement system, an important part of the innate system, is known to play a central role in many immune mediated kidney diseases. All parts of the complement system including the classical, alternative, and mannose-binding lectin pathways have been implicated in complement-mediated kidney injury. Although complement components are thought to be mainly synthesized in the liver and activated in the circulation, emerging data suggest that complement is synthesized and activated inside the kidney leading to direct injury. Urinary complement biomarkers are likely a better reflection of inflammation within the kidneys as compared to traditional serum complement biomarkers which may be influenced by systemic inflammation. In addition, urinary complement biomarkers have the advantage of being non-invasive and easily accessible. With the rise of therapies targeting the complement pathways, there is a critical need to better understand the role of complement in kidney diseases and to develop reliable and non-invasive biomarkers to assess disease activity, predict treatment response and guide therapeutic interventions. In this review, we summarized the current knowledge on urinary complement biomarkers of kidney diseases due to immune complex deposition (lupus nephritis, primary membranous nephropathy, IgA nephropathy) and due to activation of the alternative pathway (C3 glomerulopathy, thrombotic microangiography, ANCA-associated vasculitis). We also address the limitations of current research and propose future directions for the discovery of urinary complement biomarkers.
Topics: Humans; Biomarkers; Complement System Proteins; Kidney Diseases; Animals; Complement Activation
PubMed: 38895123
DOI: 10.3389/fimmu.2024.1357869