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Frontiers in Cellular and Infection... 2024This study unveils the intricate functional association between cyclic di-3',5'-adenylic acid (c-di-AMP) signaling, cellular bioenergetics, and the regulation of...
BACKGROUND
This study unveils the intricate functional association between cyclic di-3',5'-adenylic acid (c-di-AMP) signaling, cellular bioenergetics, and the regulation of lipopolysaccharide (LPS) profile in , a Gram-negative obligate anaerobe considered as a keystone pathogen involved in the pathogenesis of chronic periodontitis. Previous research has identified variations in LPS profile as a major virulence factor, yet the underlying mechanism of its modulation has remained elusive.
METHODS
We employed a comprehensive methodological approach, combining two mutants exhibiting varying levels of c-di-AMP compared to the wild type, alongside an optimized analytical methodology that combines conventional mass spectrometry techniques with a novel approach known as FLAT.
RESULTS
We demonstrate that c-di-AMP acts as a metabolic nexus, connecting bioenergetic status to nuanced shifts in fatty acid and glycosyl profiles within LPS. Notably, the predicted regulator gene , serving as a potent regulator of c-di-AMP synthesis, was found essential for producing N-acetylgalactosamine and an unidentified glycolipid class associated with the LPS profile.
CONCLUSION
The multifaceted roles of c-di-AMP in bacterial physiology are underscored, emphasizing its significance in orchestrating adaptive responses to stimuli. Furthermore, our findings illuminate the significance of LPS variations and c-di-AMP signaling in determining the biological activities and immunostimulatory potential of LPS, promoting a pathoadaptive strategy. The study expands the understanding of c-di-AMP pathways in Gram-negative species, laying a foundation for future investigations into the mechanisms governing variations in LPS structure at the molecular level and their implications for host-pathogen interactions.
Topics: Porphyromonas gingivalis; Lipopolysaccharides; Signal Transduction; Virulence Factors; Gene Expression Regulation, Bacterial; Energy Metabolism; Dinucleoside Phosphates; Fatty Acids; Humans; Bacterial Proteins
PubMed: 38933693
DOI: 10.3389/fcimb.2024.1418651 -
International Journal of Molecular... May 2024The effects of the enzyme N-acetylgalactosamine-4-sulfatase (Arylsulfatase B, ARSB), which removes the 4-sulfate group at the non-reducing end of chondroitin 4-sulfate,...
The effects of the enzyme N-acetylgalactosamine-4-sulfatase (Arylsulfatase B, ARSB), which removes the 4-sulfate group at the non-reducing end of chondroitin 4-sulfate, on the expression of PD-L1 were determined, and the underlying mechanism of PD-L1 expression was elucidated. Initial experiments in human melanoma cells (A375) showed that PD-L1 expression increased from 357 ± 31 to 796 ± 50 pg/mg protein ( < 10) when ARSB was silenced in A375 cells. In subcutaneous B16F10 murine melanomas, PD-L1 declined from 1227 ± 189 to 583 ± 110 pg/mg protein ( = 1.67 × 10), a decline of 52%, following treatment with exogenous, bioactive recombinant ARSB. This decline occurred in association with reduced tumor growth and prolongation of survival, as previously reported. The mechanism of regulation of PD-L1 expression by ARSB is attributed to ARSB-mediated alteration in chondroitin 4-sulfation, leading to changes in free galectin-3, c-Jun nuclear localization, HDAC3 expression, and effects of acetyl-H3 on the PD-L1 promoter. These findings indicate that changes in ARSB contribute to the expression of PD-L1 in melanoma and can thereby affect the immune checkpoint response. Exogenous ARSB acted on melanoma cells and normal melanocytes through the IGF2 receptor. The decline in PD-L1 expression by exogenous ARSB may contribute to the impact of ARSB on melanoma progression.
Topics: Animals; Humans; Epigenesis, Genetic; Mice; N-Acetylgalactosamine-4-Sulfatase; B7-H1 Antigen; Histone Deacetylases; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Melanoma, Experimental; Melanoma; Galectin 3; Promoter Regions, Genetic; Blood Proteins; Galectins
PubMed: 38892038
DOI: 10.3390/ijms25115851 -
Molecular & Cellular Proteomics : MCP Jun 2024Substance use disorder is a major concern, with few therapeutic options. Heparan sulfate (HS) and chondroitin sulfate (CS) interact with a plethora of growth factors and...
Substance use disorder is a major concern, with few therapeutic options. Heparan sulfate (HS) and chondroitin sulfate (CS) interact with a plethora of growth factors and their receptors and have profound effects on cellular signaling. Thus, targeting these dynamic interactions might represent a potential novel therapeutic modality. In the present study, we performed mass spectrometry-based glycomic and proteomic analysis to understand the effects of cocaine and methamphetamine (METH) on HS, CS, and the proteome of two brain regions critically involved in drug addiction: the lateral hypothalamus (LH) and the striatum (ST). We observed that cocaine and METH significantly alter HS and CS abundances as well as sulfate contents and composition. In particular, repeated METH or cocaine treatments reduced CS 4-O-sulfation and increased CS 6-O-sulfation. Since C4S and C6S exercise differential effects on axon growth, regeneration and plasticity, these changes likely contribute to drug-induced neural plasticity in these brain regions. Notably, we observed that restoring these alterations by increasing CS 4-0 levels in the LH by adeno-associated virus (AAV) delivery of an shRNA to Arylsulfatase B (N-acetylgalactosamine-4-sulfatase, ARSB) ameliorated anxiety and prevented the expression of preference for cocaine in a novelty induced conditioned place preference test during cocaine withdrawal. Finally, proteomics analyses revealed a number of aberrant proteins in METH- and cocaine-treated vs. saline-treated mice, including MYPR, KCC2A, SYN2, TENR, CALX, ANXA7, HDGF, NCAN, and CSPG5, and oxidative phosphorylation among the top perturbed pathway. Taken together, these data support the role of HS, CS, and associated proteins in stimulants abuse and suggest that manipulation of HSPGs can represent a novel therapeutic strategy.
PubMed: 38880242
DOI: 10.1016/j.mcpro.2024.100803 -
Journal of Chromatography. A Jun 2024In recent years, many nucleic acid-based pharmaceuticals have been approved and entered the market, and even a larger number are in late stage clinical trials....
In recent years, many nucleic acid-based pharmaceuticals have been approved and entered the market, and even a larger number are in late stage clinical trials. Conventional oligonucleotides are facing issues in vivo like fast renal clearance and nuclease degradation. Therefore, to increase their stability, phosphorothioation is a frequent modification of therapeutic oligonucleotides (ONs) which also leads to improved binding affinity facilitating cell internalization and intracellular distribution. At the same time, by replacing a phosphodiester linkage with a phosphorothioate group, a phosphorous stereogenic center is generated which causes the formation of R- and S-diastereomers. It increases the structural diversity. For example, with 15 of those phosphorothioate (PS) linkages, 32,768 different diastereomers are expected. Since the phosphorothioate is introduced non-stereoselectively, the molecular complexity of the resultant phosphorothioate ON products is tremendously increased impeding the chromatographic separation in the course of quality control. Since distinct phosphorothioate diastereomers have different bioactivities and pharmacological properties, there is increasing interest in implications of stereoisomerism of phosphorothiate oligonucleotides. From a quality and regulatory viewpoint, batch-to-batch reproducibility of the diastereomer profile may be of significant concern. In order to address this issue, this study investigates the stereoselectivity of LC methods for two phosphorothioate oligonucleotide (PSO) compounds differing in their molecular size and numbers of PS linkages. Diastereoselectivity of ion-pairing reversed-phase liquid chromatography (IP-RPLC), RPLC without ion-pairing agents and LC with chiral polysaccharide-based column were evaluated for model PSOs and an active pharmaceutical ingredient (API) of PSO with trivalent N-acetylgalactosamine (GalNAc) conjugate. Due to the structural complexity of PSOs, the separation power for the diastereomer mixture was increased by using sequential selective comprehensive two-dimensional chromatography with an amylose tris(α-methylbenzylcarbamate)-immobilized chiral stationary phase (CSP) in the first dimension and ion-pair RPLC with ethylammonium acetate in the second dimension. Improved diastereomer selectivity was obtained and a larger number of peaks could be separated.
PubMed: 38879975
DOI: 10.1016/j.chroma.2024.465076 -
BMC Medical Genomics Jun 2024Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disease caused by biallelic variants in the N-acetylgalactosamine-6-sulfatase (GALNS) gene and is...
BACKGROUND
Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disease caused by biallelic variants in the N-acetylgalactosamine-6-sulfatase (GALNS) gene and is characterized by progressive and multi-system involvements, dominantly with skeletal deformities. A mild form of MPS IVA often presents with atypical symptoms and can go unrecognized for years.
METHODS
The diagnosis of MPS IVA was confirmed via GALNS enzyme activity testing in leukocytes. Clinical features were collected. Molecular analysis was performed by next generation sequence and Sanger sequencing of the GALNS gene. The pathogenicity of the deep intron variant was verified by mRNA analyses.
RESULTS
Thirteen patients with mild MPS IVA from six families were included. All probands first visit pediatric orthopedists and it took 5.6 years to be diagnosed after the disease onset. The most common symptoms in our series were waddling gait (85%), short neck (69%) and flat feet (62%). Radiologic findings indicated skeletal abnormalities in all patients, especially modification of the vertebral bodies (100%) and acetabular and femoral head dysplasia (100%). Five novel GALNS variants, including c.121-2_121-1insTTTGCTGGCATATGCA, E2 deletion, c.569 A > G, c.898 + 2 T > A, and c.1139 + 2 T > C, were identified. The most common variant, a deep intron variant NM_000512.5: c.121-210 C > T (NM_001323544.2: c.129 C > T, p.G43G), was revealed to result in an 11 bp deletion (c.128_138delGCGATGCTGAG, p.Gly43Aspfs*5) on GALNS mRNA in the GALNS transcript of NM_001323544.2.
CONCLUSIONS
This study provides significant insights into the clinical features and molecular characteristics that contribute to the early diagnosis of mild MPS IVA. On the basis of our cohort, orthopedists need to be able to recognize signs and symptoms of mild MPS IVA as well as the molecular and biochemical diagnosis so that an early diagnosis and treatment can be instituted.
Topics: Humans; Male; Mucopolysaccharidosis IV; Child; Female; Delayed Diagnosis; Child, Preschool; Adolescent; Chondroitinsulfatases; Mutation
PubMed: 38831290
DOI: 10.1186/s12920-024-01910-x -
MLife Mar 2024O-glycosylation is an ancient yet underappreciated protein posttranslational modification, on which many bacteria and viruses heavily rely to perform critical biological... (Review)
Review
O-glycosylation is an ancient yet underappreciated protein posttranslational modification, on which many bacteria and viruses heavily rely to perform critical biological functions involved in numerous infectious diseases or even cancer. But due to the innate complexity of O-glycosylation, research techniques have been limited to study its exact role in viral attachment and entry, assembly and exit, spreading in the host cells, and the innate and adaptive immunity of the host. Recently, the advent of many newly developed methodologies (e.g., mass spectrometry, chemical biology tools, and molecular dynamics simulations) has renewed and rekindled the interest in viral-related O-glycosylation in both viral proteins and host cells, which is further fueled by the COVID-19 pandemic. In this review, we summarize recent advances in viral-related O-glycosylation, with a particular emphasis on the mucin-type O-linked α-N-acetylgalactosamine (O-GalNAc) on viral proteins and the intracellular O-linked β-N-acetylglucosamine (O-GlcNAc) modifications on host proteins. We hope to provide valuable insights into the development of antiviral reagents or vaccines for better prevention or treatment of infectious diseases.
PubMed: 38827513
DOI: 10.1002/mlf2.12105 -
RSC Advances May 2024GalNAc-conjugated siRNA has shown remarkable potential in liver-targeted delivery in recent years. In general, tetrahydroxymethylmethane or other branching clusters...
GalNAc-conjugated siRNA has shown remarkable potential in liver-targeted delivery in recent years. In general, tetrahydroxymethylmethane or other branching clusters constitute the basis of GalNAc's structure, which yields trivalent or tetravalent ligands. A novel diamine-scaffold GalNAc conjugate was synthesized and evaluated for its efficiency in siRNA administration. It exhibits comparable siRNA delivery effectiveness to a GalNAc NAG37 phase II clinical drug candidate targeting ANGPTL3. In addition, it exhibits more powerful silencing activity when connected to the 3'-end of the sense strand with an additional PS-linkage instead of a PO linkage between the ligand and the oligomer compared to a GalNAc L96 standard targeting TTR. Taken together, the incorporation of a diamine-scaffold into the GalNAc conjugate structure has potential in the field of gene therapy.
PubMed: 38818366
DOI: 10.1039/d4ra03023k -
Journal of Biomedical Research Jan 2024Core 1 synthase glycoprotein-N-acetylgalactosamine 3-β-galactosyltransferase 1 (C1GALT1) is known to play a critical role in the development of gastric cancer, but few...
Core 1 synthase glycoprotein-N-acetylgalactosamine 3-β-galactosyltransferase 1 (C1GALT1) is known to play a critical role in the development of gastric cancer, but few studies have elucidated associations between genetic variants in and gastric cancer susceptibility. By using the genome-wide association study data from the database of Genotype and Phenotype (dbGAP), we evaluated these associations with a logistic regression model and identified that the rs35999583 in was associated with gastric cancer risk (odd ratio, 0.83; 95% confidence interval [CI], 0.75-0.92; = 3.95 × 10 ]. mRNA expression was significantly higher in gastric tumor tissues, and gastric cancer patients with higher mRNA levels had the worse overall survival rates (hazards ratio, 1.33; 95% CI, 1.05-1.68; = 1.90 × 10 ). Furthermore, we found that copy number variations differed in various immune cells and mRNA expression was positively correlated with the infiltrating levels of CD4 T cells and macrophages. These results highlight that genetic variants of may play an important role in gastric cancer risk and provide a new insight for to be a promising predictor of gastric cancer susceptibility and immune status.
PubMed: 38807485
DOI: 10.7555/JBR.37.20230161 -
BioRxiv : the Preprint Server For... May 2024Proteins harboring intrinsically disordered regions (IDRs) that lack regular secondary or tertiary structure are abundant across three domains of life. Here, using a...
Proteins harboring intrinsically disordered regions (IDRs) that lack regular secondary or tertiary structure are abundant across three domains of life. Here, using a deep neural network (DNN)-based method we predict IDRs in the extracytoplasmic proteome of , and . We identify a subset of the serine/threonine-rich IDRs and demonstrate that they are -glycosylated with glucose by a GtrB-like glucosyltransferase in and , and N-acetylgalactosamine by a Pgf-dependent mechanism in . Loss of glycosylation leads to a defect in biofilm formation under ethanol-stressed conditions in . We link this phenotype to a C-terminal IDR of peptidyl-prolyl isomerase PrsA which is protected from proteolytic degradation by -glycosylation. The IDR length attenuates the efficiency of glycosylation and expression of PrsA. Taken together, our data support a model in which extracytoplasmic IDRs function as dynamic switches of protein homeostasis in streptococci.
PubMed: 38746434
DOI: 10.1101/2024.05.05.592596 -
Nucleic Acids Research Jun 2024Oral delivery is the most widely used and convenient route of administration of medicine. However, oral administration of hydrophilic macromolecules is commonly limited...
Oral delivery is the most widely used and convenient route of administration of medicine. However, oral administration of hydrophilic macromolecules is commonly limited by low intestinal permeability and pre-systemic degradation in the gastrointestinal (GI) tract. Overcoming some of these challenges allowed emergence of oral dosage forms of peptide-based drugs in clinical settings. Antisense oligonucleotides (ASOs) have also been investigated for oral administration but despite the recent progress, the bioavailability remains low. Given the advancement with highly potent and durable trivalent N-acetylgalactosamine (GalNAc)-conjugated small interfering RNAs (siRNAs) via subcutaneous (s.c.) injection, we explored their activities after oral administration. We report robust RNA interference (RNAi) activity of orally administrated GalNAc-siRNAs co-formulated with permeation enhancers (PEs) in rodents and non-human primates (NHPs). The relative bioavailability calculated from NHP liver exposure was <2.0% despite minimal enzymatic degradation in the GI. To investigate the impact of oligonucleotide size on oral delivery, highly specific GalNAc-conjugated single-stranded oligonucleotides known as REVERSIRs with different lengths were employed and their activities for reversal of RNAi effect were monitored. Our data suggests that intestinal permeability is highly influenced by the size of oligonucleotides. Further improvements in the potency of siRNA and PE could make oral delivery of GalNAc-siRNAs as a practical solution.
Topics: Animals; Acetylgalactosamine; RNA, Small Interfering; Administration, Oral; Mice; Rats; RNA Interference; Male; Biological Availability; Humans; Rats, Sprague-Dawley; Macaca fascicularis; Liver; Macaca mulatta
PubMed: 38742636
DOI: 10.1093/nar/gkae350