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Gastroenterology Apr 2024Gastric cancer is often accompanied by a loss of mucin 6 (MUC6), but its pathogenic role in gastric carcinogenesis remains unclear.
BACKGROUND & AIMS
Gastric cancer is often accompanied by a loss of mucin 6 (MUC6), but its pathogenic role in gastric carcinogenesis remains unclear.
METHODS
Muc6 knockout (Muc6) mice and Muc6-dsRED mice were newly generated. Tff1Cre, Golph3, R26-Golgi-mCherry, Hes1, Cosmc, and A4gnt mice were also used. Histology, DNA and RNA, proteins, and sugar chains were analyzed by whole-exon DNA sequence, RNA sequence, immunohistochemistry, lectin-binding assays, and liquid chromatography-mass spectrometry analysis. Gastric organoids and cell lines were used for in vitro assays and xenograft experiments.
RESULTS
Deletion of Muc6 in mice spontaneously causes pan-gastritis and invasive gastric cancers. Muc6-deficient tumor growth was dependent on mitogen-activated protein kinase activation, mediated by Golgi stress-induced up-regulation of Golgi phosphoprotein 3. Glycomic profiling revealed aberrant expression of mannose-rich N-linked glycans in gastric tumors, detected with banana lectin in association with lack of MUC6 expression. We identified a precursor of clusterin as a binding partner of mannose glycans. Mitogen-activated protein kinase activation, Golgi stress responses, and aberrant mannose expression are found in separate Cosmc- and A4gnt-deficient mouse models that lack normal O-glycosylation. Banana lectin-drug conjugates proved an effective treatment for mannose-rich murine and human gastric cancer.
CONCLUSIONS
We propose that Golgi stress responses and aberrant glycans are important drivers of and promising new therapeutic targets for gastric cancer.
PubMed: 38583723
DOI: 10.1053/j.gastro.2024.03.037 -
Proceedings of the National Academy of... Dec 2023The atypical protein kinase ALPK1 is activated by the bacterial nucleotide sugar ADP-heptose and phosphorylates TIFA to switch on a signaling pathway that combats...
The atypical protein kinase ALPK1 is activated by the bacterial nucleotide sugar ADP-heptose and phosphorylates TIFA to switch on a signaling pathway that combats microbial infection. In contrast, ALPK1 mutations cause two human diseases: the ALPK1[T237M] and ALPK1[Y254C] mutations underlie ROSAH syndrome (retinal dystrophy, optic nerve oedema, splenomegaly, anhidrosis, and migraine headache), while the ALPK1[V1092A] mutation accounts for 45% of spiradenoma and 30% of spiradenocarcinoma cases studied. In this study, we demonstrate that unlike wild-type (WT) ALPK1, the disease-causing ALPK1 mutants trigger the TIFA-dependent activation of an NF-κB/activator protein 1 reporter gene in the absence of ADP-heptose, which can be suppressed by either of two additional mutations in the ADP-heptose binding site that prevent the activation of WT ALPK1 by ADP-heptose. These observations are explained by our key finding that although ALPK1[T237M] and ALPK1[V1092A] are activated by bacterial ADP-heptose, they can also be activated by nucleotide sugars present in human cells (UDP-mannose, ADP-ribose, and cyclic ADP-ribose) which can be prevented by disruption of the ADP-heptose binding site. The ALPK1[V1092A] mutant was also activated by GDP-mannose, which did not activate ALPK1[T237M]. These are new examples of disease-causing mutations permitting the allosteric activation of an enzyme by endogenous molecules that the WT enzyme does not respond to. We propose that the loss of the specificity of ALPK1 for bacterial ADP-heptose underlies ROSAH syndrome and spiradenoma/spiradenocarcinoma caused by ALPK1 mutation.
Topics: Humans; Nucleotides; Sugars; Splenomegaly; Acrospiroma; Mannose; Sweat Gland Neoplasms; Heptoses
PubMed: 38060563
DOI: 10.1073/pnas.2313148120 -
Journal of Materials Chemistry. B Nov 2023Phototherapy is a local and precise therapeutic technique for tumor treatment. However, the therapeutic effects of photothermal and photodynamic therapies are inevitably...
Phototherapy is a local and precise therapeutic technique for tumor treatment. However, the therapeutic effects of photothermal and photodynamic therapies are inevitably encountered by hypoxia of the tumor microenvironment and heat shock protein induced by hyperthermia, respectively. Herein, we found that mannose, a glucose analog, could reverse tumor hypoxia by inhibiting glycolysis of cancer cells and suppressing the expression of heat shock protein through inhibiting cellular adenosine triphosphate (ATP) generation. Next, we used lipid nanoparticles simultaneously loaded with indocyanine green (ICG) and mannose molecules, named imLipo, for tumor therapy. Both and experiments evidenced that the imLipo nanoplatform has significant therapeutic efficacy through synergistic phototherapy under single near-infrared laser irradiation. This work shows that glycolysis inhibition can overcome the challenges of phototherapy. In addition, all three parts (mannose, ICG, and lipid) of imLipo are clinically approved and our designed nanoplatforms have great potential for future tumor treatment.
Topics: Humans; Triple Negative Breast Neoplasms; Mannose; Hyperthermia, Induced; Phototherapy; Glycolysis; Heat-Shock Proteins; Tumor Microenvironment
PubMed: 37921004
DOI: 10.1039/d3tb02059b -
Frontiers in Immunology 2024Inflammatory bowel disease (IBD) greatly affects human quality of life. Mannose has been reported to be used to treat IBD, but the mechanism is currently unknown.
BACKGROUND
Inflammatory bowel disease (IBD) greatly affects human quality of life. Mannose has been reported to be used to treat IBD, but the mechanism is currently unknown.
METHODS
C57/BL mice were used as research subjects, and the mouse acute colitis model was induced using dextran sulfate sodium salt (DSS). After oral administration of mannose, the body weights and disease activity index (DAI) scores of the mice were observed. The colon lengths, histopathological sections, fecal content microbial sequencing, colon epithelial inflammatory genes, and tight junction protein Occludin-1 expression levels were measured. We further used the feces of mice that had been orally administered mannose to perform fecal bacterial transplantation on the mice with DSS-induced colitis and detected the colitis-related indicators.
RESULTS
Oral administration of mannose increased body weights and colon lengths and reduced DAI scores in mice with DSS-induced colitis. In addition, it reduced the expression of colon inflammatory genes and the levels of serum inflammatory factors (TNF-α, IL-6, and IL-1β), further enhancing the expression level of the colonic Occludin-1 protein and alleviating the toxic response of DSS to the intestinal epithelium of the mice. In addition, gut microbial sequencing revealed that mannose increased the abundance and diversity of intestinal flora. Additionally, after using the feces of the mannose-treated mice to perform fecal bacterial transplantation on the mice with DSS-induced colitis, they showed the same phenotype as the mannose-treated mice, and both of them alleviated the intestinal toxic reaction induced by the DSS. It also reduced the expression of intestinal inflammatory genes (TNF-α, IL-6, and IL-1β) and enhanced the expression level of the colonic Occludin-1 protein.
CONCLUSION
Mannose can treat DSS-induced colitis in mice, possibly by regulating intestinal microorganisms to enhance the intestinal immune barrier function and reduce the intestinal inflammatory response.
Topics: Mice; Humans; Animals; Gastrointestinal Microbiome; Mannose; Dextran Sulfate; Interleukin-6; Tumor Necrosis Factor-alpha; Occludin; Quality of Life; Colitis; Inflammatory Bowel Diseases; Sodium Chloride; Sodium Chloride, Dietary; Body Weight
PubMed: 38529272
DOI: 10.3389/fimmu.2024.1365457 -
International Journal of Cardiology Oct 2023The lectin pathway has been demonstrated to play a critical role in the pathological process of myocardial ischemia/reperfusion injury (IRI). Mannose-binding lectin...
BACKGROUND
The lectin pathway has been demonstrated to play a critical role in the pathological process of myocardial ischemia/reperfusion injury (IRI). Mannose-binding lectin (MBL)-associated serine protease-1 (MASP-1), especially different from other components of the lectin pathway, mediates proinflammatory and procoagulant reactions independent of complement cascades. However, the role of MASP-1 in myocardial IRI remains unknown so far.
METHODS
Myocardial IRI was established with 45 min ischemia and 24 h reperfusion in mice. C1 inhibitor, as the natural inhibitor of MASP-1, was administrated at 20 IU/Kg via tail vein 5 min before surgical operation. Cardiac function and myocardial infarct size were assessed. Myocardial histology and fibrosis were evaluated by H&E and Masson staining, respectively. Deposition of MASP-1, expression of PAR-1/4 and neutrophil extracellular traps (NET) were investigated on myocardium tissue by IHC staining. Cell apoptosis was detected by TUNEL assay. Levels of myocardial enzymes and proinflammatory cytokines were determined by ELISA.
RESULTS
Inhibition of MASP-1 with C1 INH improved cardiac function and alleviated myocardium tissue injury (infarct size, enzymes, histology and fibrosis) after myocardial IRI. Deposition of MASP-1 and expression PAR-1, as well as NET formation in myocardial tissue were suppressed by MASP-1 inhibitor, while PAR-4 was elevated. Levels of apoptosis, HMGB-1 and IL-6 were lower after blocking MASP-1. Yet, IL-8 and TNF-α remained unchanged.
CONCLUSIONS
MASP-1, as a new contributor, played a critical role in myocardial IRI. Inhibition of MASP-1 protected myocardial tissue from IRI probably via regulation of PARs/NET pathway. This may provide a novel target strategy against myocardial IRI.
Topics: Mice; Animals; Myocardial Reperfusion Injury; Complement Pathway, Mannose-Binding Lectin; Mannose-Binding Protein-Associated Serine Proteases; Lectins; Mannose-Binding Lectins
PubMed: 37473815
DOI: 10.1016/j.ijcard.2023.131193 -
Turkish Journal of Obstetrics and... Dec 2023This study aimed to evaluate the relationship between mannose-binding lectin-associated serine protease-2 as an immune system parameter and neutrophil lymphocyte ratio...
OBJECTIVE
This study aimed to evaluate the relationship between mannose-binding lectin-associated serine protease-2 as an immune system parameter and neutrophil lymphocyte ratio (NLR) as an inflammatory parameter to predict cervical cancer metastasis.
MATERIALS AND METHODS
This cross-sectional study included 70 patients diagnosed with cervical cancer between January 2022 and February 2023 at Dr. Wahidin Sudirohusodo Hospital, Hasanuddin University Hospital, and Ibnu Sina Hospital, Makassar, Indonesia. Blood samples taken before therapy as well as clinical and histological data were gathered and examined. MASP-2 levels and NLR were measured by ELISA and flow cytometry respectively.
RESULTS
The median age of the patients was 46 years (range, 24-72 years), with the majority of patients aged between 41 and 52 years. Statistical analysis showed that MASP-2 was associated with cervical cancer stage (p≤0.000), organ metastasis (p=0.011), and lymphovascular invasion (p=0.036). In addition, NLR was associated with cervical cancer stage (p=0.004), histopathology type (p=0.031), tumor size (p=0.019), and organ metastasis (p=0.013).
CONCLUSION
Pretreatment with MASP-2 as an immune system parameter and NLR as an inflammatory parameter is associated with cervical cancer metastasis. The NLR indicator can be applied in clinical practice because it is simple and reasonably priced.
PubMed: 38073222
DOI: 10.4274/tjod.galenos.2023.80912 -
BioRxiv : the Preprint Server For... Dec 2023Since >3 years, SARS-CoV-2 has plunged humans into a colossal pandemic. Henceforth, multiple waves of infection have swept through the human population, led by variants...
Since >3 years, SARS-CoV-2 has plunged humans into a colossal pandemic. Henceforth, multiple waves of infection have swept through the human population, led by variants that were able to partially evade acquired immunity. The co-evolution of SARS-CoV-2 variants with human immunity provides an excellent opportunity to study the interaction between viral pathogens and their human hosts. The heavily -glycosylated spike-protein of SARS-CoV-2 plays a pivotal role in initiating infection and is the target for host immune-response, both of which are impacted by host-installed -glycans. Using highly-sensitive DeGlyPHER approach, we compared the -glycan landscape on spikes of the SARS-CoV-2 Wuhan-Hu-1 strain to seven WHO-defined variants of concern/interest, using recombinantly expressed, soluble spike-protein trimers, sharing same stabilizing-mutations. We found that -glycan processing is conserved at most sites. However, in multiple variants, processing of -glycans from high mannose- to complex-type is reduced at sites N165, N343 and N616, implicated in spike-protein function.
PubMed: 37214937
DOI: 10.1101/2023.05.08.539897 -
Frontiers in Immunology 2023Overactivation of the lectin pathway of complement plays a pathogenic role in a broad range of immune-mediated and inflammatory disorders; mannan-binding...
INTRODUCTION
Overactivation of the lectin pathway of complement plays a pathogenic role in a broad range of immune-mediated and inflammatory disorders; mannan-binding lectin-associated serine protease-2 (MASP-2) is the key effector enzyme of the lectin pathway. We developed a fully human monoclonal antibody, narsoplimab, to bind to MASP-2 and specifically inhibit lectin pathway activation. Herein, we describe the preclinical characterization of narsoplimab that supports its evaluation in clinical trials.
METHODS AND RESULTS
ELISA binding studies demonstrated that narsoplimab interacted with both zymogen and enzymatically active forms of human MASP-2 with high affinity (K 0.062 and 0.089 nM, respectively) and a selectivity ratio of >5,000-fold relative to closely related serine proteases C1r, C1s, MASP-1, and MASP-3. Interaction studies using surface plasmon resonance and ELISA demonstrated approximately 100-fold greater binding affinity for intact narsoplimab compared to a monovalent antigen binding fragment, suggesting an important contribution of functional bivalency to high-affinity binding. In functional assays conducted in dilute serum under pathway-specific assay conditions, narsoplimab selectively inhibited lectin pathway-dependent activation of C5b-9 with high potency (IC ~ 1 nM) but had no observable effect on classical pathway or alternative pathway activity at concentrations up to 500 nM. In functional assays conducted in 90% serum, narsoplimab inhibited lectin pathway activation in human serum with high potency (IC ~ 3.4 nM) whereas its potency in cynomolgus monkey serum was approximately 10-fold lower (IC ~ 33 nM). Following single dose intravenous administration to cynomolgus monkeys, narsoplimab exposure increased in an approximately dose-proportional manner. Clear dose-dependent pharmacodynamic responses were observed at doses >1.5 mg/kg, as evidenced by a reduction in lectin pathway activity assessed that increased in magnitude and duration with increasing dose. Analysis of pharmacokinetic and pharmacodynamic data revealed a well-defined concentration-effect relationship with an EC value of approximately 6.1 μg/mL, which was comparable to the functional potency (IC 33 nM; ~ 5 μg/mL).
DISCUSSION
Based on these results, narsoplimab has been evaluated in clinical trials for the treatment of conditions associated with inappropriate lectin pathway activation, such as hematopoietic stem cell transplantation-associated thrombotic microangiopathy.
Topics: Animals; Humans; Mannose-Binding Protein-Associated Serine Proteases; Lectins; Macaca fascicularis; Serine Endopeptidases
PubMed: 38022610
DOI: 10.3389/fimmu.2023.1297352 -
Cell Reports Jan 2024Complement is a fundamental innate immune response component. Its alterations are associated with severe systemic diseases. To illuminate the complement's genetic...
Complement is a fundamental innate immune response component. Its alterations are associated with severe systemic diseases. To illuminate the complement's genetic underpinnings, we conduct genome-wide association studies of the functional activity of the classical (CP), lectin (LP), and alternative (AP) complement pathways in the Cooperative Health Research in South Tyrol study (n = 4,990). We identify seven loci, encompassing 13 independent, pathway-specific variants located in or near complement genes (CFHR4, C7, C2, MBL2) and non-complement genes (PDE3A, TNXB, ABO), explaining up to 74% of complement pathways' genetic heritability and implicating long-range haplotypes associated with LP at MBL2. Two-sample Mendelian randomization analyses, supported by transcriptome- and proteome-wide colocalization, confirm known causal pathways, establish within-complement feedback loops, and implicate causality of ABO on LP and of CFHR2 and C7 on AP. LP causally influences collectin-11 and KAAG1 levels and the risk of mouth ulcers. These results build a comprehensive resource to investigate the role of complement in human health.
Topics: Humans; Genome-Wide Association Study; Complement Activation; Complement System Proteins; Lectins; Haplotypes; Mannose-Binding Lectin
PubMed: 38159276
DOI: 10.1016/j.celrep.2023.113611 -
Advanced Science (Weinheim,... Jan 2024Targeting the niche components surrounding glioblastoma stem cells (GSCs) helps to develop more effective glioblastoma treatments. However, the mechanisms underlying the...
Targeting the niche components surrounding glioblastoma stem cells (GSCs) helps to develop more effective glioblastoma treatments. However, the mechanisms underlying the crosstalk between GSCs and microenvironment remain largely unknown. Clarifying the extracellular molecules binding to GSCs marker CD133 helps to elucidate the mechanism of the communication between GSCs and the microenvironment. Here, it is found that the extracellular domain of high mannose type CD133 physically interacts with Collagen 1 (COL1) in GSCs. COL1, mainly secreted by cancer-associated fibroblasts, is a niche component for GSCs. COL1 enhances the interaction between CD133 and p85 and activates Akt phosphorylation. Activation of Akt pathway increases transcription factor ATF4 protein level, subsequently enhances SLC1A5-dependent glutamine uptake and glutathione synthesis. The inhibition of CD133-COL1 interaction or down-regulation of SLC1A5 reduces COL1-accelerated GSCs self-renewal and tumorigenesis. Analysis of glioma samples reveals that the level of COL1 is correlated with histopathological grade of glioma and the expression of SLC1A5. Collectively, COL1, a niche component for GSCs, enhances the tumorigenesis of GSCs partially through CD133-Akt-SLC1A5 signaling axis, providing a new mechanism underlying the cross-talk between GSCs and extracellular matrix (ECM) microenvironment.
Topics: Humans; Glioblastoma; Glutamine; Mannose; Proto-Oncogene Proteins c-akt; Neoplastic Stem Cells; Carcinogenesis; Cell Transformation, Neoplastic; Glioma; Collagen; Tumor Microenvironment; Minor Histocompatibility Antigens; Amino Acid Transport System ASC
PubMed: 37997289
DOI: 10.1002/advs.202306715