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Biomolecules Nov 2023Acid ceramidase (AC) is a lysosomal enzyme required to hydrolyze ceramide to sphingosine by the removal of the fatty acid moiety. An inherited deficiency in this...
Acid ceramidase (AC) is a lysosomal enzyme required to hydrolyze ceramide to sphingosine by the removal of the fatty acid moiety. An inherited deficiency in this activity results in two disorders, Farber Lipogranulomatosis and spinal muscular atrophy with myoclonic epilepsy, leading to the accumulation of ceramides and other sphingolipids in various cells and tissues. In addition to ceramide hydrolysis, several other activities have been attributed to AC, including a reverse reaction that synthesizes ceramide from free fatty acids and sphingosine, and a deacylase activity that removes fatty acids from complex lipids such as sphingomyelin and glycosphingolipids. A close association of AC with another important enzyme of sphingolipid metabolism, acid sphingomyelinase (ASM), has also been observed. Herein, we used a highly purified recombinant human AC (rhAC) and novel UPLC-based assay methods to investigate the recently described deacylase activity of rhAC against three sphingolipid substrates, sphingomyelin, galactosyl- and glucosylceramide. No deacylase activities were detected using this method, although we did unexpectedly identify a significant ASM activity using natural (C-18) and artificial (Bodipy-C12) sphingomyelin substrates as well as the ASM-specific fluorogenic substrate, hexadecanoylamino-4-methylumbelliferyl phosphorylcholine (HMU-PC). We showed that this ASM activity was not due to contaminating, hamster-derived ASM in the rhAC preparation, and that the treatment of ASM-knockout mice with rhAC significantly reduced sphingomyelin storage in the liver. However, unlike the treatment with rhASM, this did not lead to elevated ceramide or sphingosine levels.
Topics: Animals; Mice; Cricetinae; Humans; Acid Ceramidase; Sphingomyelins; Sphingosine; Sphingomyelin Phosphodiesterase; Ceramides; Sphingolipids; Fatty Acids
PubMed: 38002305
DOI: 10.3390/biom13111623 -
International Journal of Molecular... Jan 2024Phosphorus-containing metabolites occupy a prominent position in cell pathways. The phosphorometabolomic approach in human sperm samples will deliver valuable...
Phosphorus-containing metabolites occupy a prominent position in cell pathways. The phosphorometabolomic approach in human sperm samples will deliver valuable information as new male fertility biomarkers could emerge. This study analyzed, by P-NMR, seminal plasma and whole semen from asthenozoospermic and normozoospermic samples (71% vs. 27% and 45% vs. 17%, total and progressive sperm motility, respectively), and also ejaculates from healthy donors. At least 16 phosphorus-containing metabolites involved in central energy metabolism and phospholipid, nucleotide, and nicotinamide metabolic pathways were assigned and different abundances between the samples with distinct sperm quality was detected. Specifically, higher levels of phosphocholine, glucose-1-phosphate, and to a lesser degree, acetyl phosphate were found in the asthenozoospermic seminal plasma. Notably, the phosphorometabolites implicated in lipid metabolism were highlighted in the seminal plasma, while those associated with carbohydrate metabolism were more abundant in the spermatozoa. Higher levels of phosphocholine, glucose-1-phosphate, and acetyl phosphate in the seminal plasma with poor quality suggest their crucial role in supporting sperm motility through energy metabolic pathways. In the seminal plasma, phosphorometabolites related to lipid metabolism were prominent; however, spermatozoa metabolism is more dependent on carbohydrate-related energy pathways. Understanding the presence and function of sperm phosphorylated metabolites will enhance our knowledge of the metabolic profile of healthy human sperm, improving assessment and differential diagnosis.
Topics: Humans; Male; Semen; Phosphorylcholine; Sperm Motility; Spermatozoa; Asthenozoospermia; Phosphorus; Semen Analysis; Organophosphates
PubMed: 38338962
DOI: 10.3390/ijms25031682 -
Ecotoxicology and Environmental Safety Jun 2023Fine particulate matter (PM) and high-fat diet (HFD) are known to contribute to blood glucose metabolic disorders. However, limited research has investigated the...
Effects of PM and high-fat diet interaction on blood glucose metabolism in adolescent male Wistar rats: A serum metabolomics analysis based on ultra-high performance liquid chromatography/mass spectrometry.
Fine particulate matter (PM) and high-fat diet (HFD) are known to contribute to blood glucose metabolic disorders. However, limited research has investigated the combined impact of PM and HFD on blood glucose metabolism. This study aimed to explore the joint effects of PM and HFD on blood glucose metabolism in rats using serum metabolomics and to identify involved metabolites and metabolic pathways. The 32 male Wistar rats were exposed to filtered air (FA) or PM (real-world inhaled, concentrated PM, 8 times the ambient level, ranging from 131.42 to 773.44 μg/m) and fed normal diet (ND) or HFD for 8 weeks. The rats were divided into four groups (n = 8/group): ND-FA, ND-PM, HFD-FA and HFD-PM groups. Blood samples were collected to determine fasting glucose (FBG), plasma insulin and glucose tolerance test and HOMA Insulin Resistance (HOMA-IR) index was calculated. Finally, the serum metabolism of rats was analyzed by ultra-high performance liquid chromatography/mass spectrometry (UHPLC-MS). Then we constructed the partial least squares discriminant analysis (PLS-DA) model to screen the differential metabolites, and performed pathway analysis to screen the main metabolic pathways. Results showed that combined effect of PM and HFD caused changes in glucose tolerance, increased FBG levels and HOMA-IR in rats and there were interactions between PM and HFD in FBG and insulin. By metabonomic analysis, the serum differential metabolites pregnenolone and progesterone, which involved in steroid hormone biosynthesis, were two different metabolites in the ND groups. In the HFD groups, the serum differential metabolites were L-tyrosine and phosphorylcholine, which involved in glycerophospholipid metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis. When PM and HFD coexist, they may lead to more severe and complex effects on glucose metabolism by affecting lipid metabolism and amino acid metabolism. Therefore, reducing PM exposure and controlling dietary structure are important measures for preventing and reducing glucose metabolism disorders.
PubMed: 37392662
DOI: 10.1016/j.ecoenv.2023.115200 -
Molecular & Cellular Proteomics : MCP Feb 2024Glycans are key to host-pathogen interactions, whereby recognition by the host and immunomodulation by the pathogen can be mediated by carbohydrate binding proteins,...
Glycans are key to host-pathogen interactions, whereby recognition by the host and immunomodulation by the pathogen can be mediated by carbohydrate binding proteins, such as lectins of the innate immune system, and their glycoconjugate ligands. Previous studies have shown that excretory-secretory products of the porcine nematode parasite Trichuris suis exert immunomodulatory effects in a glycan-dependent manner. To better understand the mechanisms of these interactions, we prepared N-glycans from T. suis and both analyzed their structures and used them to generate a natural glycan microarray. With this array, we explored the interactions of glycans with C-type lectins, C-reactive protein, and sera from T. suis-infected pigs. Glycans containing LacdiNAc and phosphorylcholine-modified glycans were associated with the highest binding by most of these proteins. In-depth analysis revealed not only fucosylated LacdiNAc motifs with and without phosphorylcholine moieties but phosphorylcholine-modified mannose and N-acetylhexosamine-substituted fucose residues, in the context of maximally tetraantennary N-glycan scaffolds. Furthermore, O-glycans also contained fucosylated motifs. In summary, the glycans of T. suis are recognized by both the innate and adaptive immune systems and also exhibit species-specific features distinguishing its glycome from those of other nematodes.
Topics: Animals; Swine; Trichuris; Phosphorylcholine; Polysaccharides; Glycosylation; Immune System
PubMed: 38182041
DOI: 10.1016/j.mcpro.2024.100711 -
The Journal of Veterinary Medical... Jun 2024Immunoglobulin A (IgA) is notable for its broad specificity toward multiple bacteria. Phosphorylcholine (PC) plays a role in the infection of pathogenic bacteria...
Immunoglobulin A (IgA) is notable for its broad specificity toward multiple bacteria. Phosphorylcholine (PC) plays a role in the infection of pathogenic bacteria carrying PC and in the induction of IgA responses in the host immune system. The commercially available mouse monoclonal IgA, TEPC15-IgA, is a distinctive antibody with specificity for PC, warranting further exploration of its response to PC-bearing enteric bacteria. In this study, using 17 different enteric bacteria, including 3 aerobic and 14 anerobic bacteria that could be cultured in vitro, we confirmed that TEPC15-IgA recognizes 4 bacterial species: Lactobacillus taiwanensis, Limosilactobacillus frumenti, Streptococcus infantis, and Escherichia coli, although reactivity varied. Interestingly, TEPC15-IgA did not react with four of six Lactobacillus species used. Moreover, distinct target molecules associated with PC in L. taiwanensis and L. frumenti were evident, differing in molecular weight. These findings suggest that the natural generation of PC-specific IgA could prevent PC-mediated infections and potentially facilitate the formation of a microflora rich in indigenous bacteria with PC, particularly in the gastrointestinal tract.
PubMed: 38839348
DOI: 10.1292/jvms.23-0441 -
Cardiovascular Research Mar 2024The adaptive immune response plays an important role in atherosclerosis. In response to a high-fat/high-cholesterol (HF/HC) diet, marginal zone B (MZB) cells activate an...
AIMS
The adaptive immune response plays an important role in atherosclerosis. In response to a high-fat/high-cholesterol (HF/HC) diet, marginal zone B (MZB) cells activate an atheroprotective programme by regulating the differentiation and accumulation of 'poorly differentiated' T follicular helper (Tfh) cells. On the other hand, Tfh cells activate the germinal centre response, which promotes atherosclerosis through the production of class-switched high-affinity antibodies. We therefore investigated the direct role of Tfh cells and the role of IL18 in Tfh differentiation in atherosclerosis.
METHODS AND RESULTS
We generated atherosclerotic mouse models with selective genetic deletion of Tfh cells, MZB cells, or IL18 signalling in Tfh cells. Surprisingly, mice lacking Tfh cells had increased atherosclerosis. Lack of Tfh not only reduced class-switched IgG antibodies against oxidation-specific epitopes (OSEs) but also reduced atheroprotective natural IgM-type anti-phosphorylcholine (PC) antibodies, despite no alteration of natural B1 cells. Moreover, the absence of Tfh cells was associated with an accumulation of MZB cells with substantially reduced ability to secrete antibodies. In the same manner, MZB cell deficiency in Ldlr-/- mice was associated with a significant decrease in atheroprotective IgM antibodies, including natural anti-PC IgM antibodies. In humans, we found a positive correlation between circulating MZB-like cells and anti-OSE IgM antibodies. Finally, we identified an important role for IL18 signalling in HF/HC diet-induced Tfh.
CONCLUSION
Our findings reveal a previously unsuspected role of MZB cells in regulating atheroprotective 'natural' IgM antibody production in a Tfh-dependent manner, which could have important pathophysiological and therapeutic implications.
Topics: Humans; Mice; Animals; Immunoglobulin M; Interleukin-18; B-Lymphocytes; Atherosclerosis; Cholesterol; T-Lymphocytes, Helper-Inducer
PubMed: 38381113
DOI: 10.1093/cvr/cvae027 -
Scientific Reports Jul 2023The complexation reactions of phosphocholine and pyrimidine nucleosides as well as nucleotides with copper(II) ions were studied in the water system. Using...
The complexation reactions of phosphocholine and pyrimidine nucleosides as well as nucleotides with copper(II) ions were studied in the water system. Using potentiometric methods and computer calculations, the stability constants of the species were determined. Using spectroscopic methods such as UV-vis, EPR, C NMR, P NMR, FT-IR and CD, the coordination mode was established for complexes created in pH range 2.5-11.0. These studies will lead to a better understanding the role of copper(II) ions in living organisms and explain the interactions between them and the studied bioligands. The differences and similarities between nucleosides and nucleotides in the studied systems were also described, which testify to the significant influence of phosphate groups on the processes of metal ion complexation and interactions between ligands.
Topics: Nucleotides; Copper; Phosphorylcholine; Molecular Structure; Pyrimidine Nucleosides; Spectroscopy, Fourier Transform Infrared; Ions; Hydrogen-Ion Concentration
PubMed: 37402775
DOI: 10.1038/s41598-023-37986-1 -
RSC Advances Sep 20232-Methacryloyloxyethyl phosphorylcholine (MPC) zwitterions were modified onto self-made graphene oxide (GO) through the atom transfer radical polymerization method. The...
2-Methacryloyloxyethyl phosphorylcholine (MPC) zwitterions were modified onto self-made graphene oxide (GO) through the atom transfer radical polymerization method. The chemical structures of the products were verified using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), It was found that the modified GO (GO-PCn) is well dispersed in water with an average hydrodynamic diameter of about 170 nm. By utilizing the 2D planar structure of this modified graphene, the irinotecan@GO-PCn composite can be loaded with about 20% of irinotecan π-π stacking interaction and exhibit pH-sensitive drug release performance, releasing faster in the acidic environment. The cytotoxicity assessments confirmed that GO-PCn composed of phosphorylcholine moiety represented low cytotoxicity and acted as a certain effect on reducing the acute toxicity of irinotecan, which established a foundation for further studies of the system in oncology therapy.
PubMed: 37790105
DOI: 10.1039/d3ra04987f -
ACS Omega Jun 2024Polymer materials are integral to diverse scientific fields, including chemical engineering and biochemical research, as well as analytical and physical chemistry. This...
Characterization of Modified PVDF Membranes Using Fourier Transform Infrared and Raman Microscopy and Infrared Nanoimaging: Challenges and Advantages of Individual Methods.
Polymer materials are integral to diverse scientific fields, including chemical engineering and biochemical research, as well as analytical and physical chemistry. This study focuses on the characterization of modified poly(vinylidene fluoride) (PVDF) membranes from both physical and chemical perspectives. Unfortunately, current surface characterization methods face various challenges when simultaneously measuring diverse material properties such as morphology and chemical composition. Addressing this issue, we introduce infrared scattering scanning near-field optical microscopy (IR-sSNOM), a modern technique with the ability to overcome limitations and provide simultaneous topographical, mechanical, and chemical information. We demonstrate the capabilities of IR-sSNOM for investigation of four samples of PVDF membranes modified with 2-(methacryloyloxyethyl)trimethylammonium iodide and/or methacryloyloxyethyl phosphorylcholine in various ratios. These membranes, desirable for their specific properties, represent a challenging material for analysis due to their thermal instability and mechanical vulnerability. Employing Fourier transform infrared (FTIR) microscopy, IR-sSNOM, and Raman microscopy, we successfully overcame these challenges by carefully selecting the experimental parameters and performing detailed characterization of the polymer samples. Valuable insights into morphological and chemical homogeneity, the abundance of modifying side chains, and the distribution of different crystal phases of PVDF were obtained. Most notably, the presence of modifying side chains was confirmed by FTIR microscopy, the Raman spectral mapping revealed the distribution of crystalline phases of the studied polymer, and the IR-sSNOM showed the abundance of chemically diverse aggregates on the surface of the membranes, thanks to the unique nanometer-scale resolution and chemical sensitivity of this technique. This comprehensive approach represents a powerful toolset for characterization of polymeric materials at the nano- and microscale. We believe that this methodology can be applied to similar samples, provided that their thermal stability is considered, opening avenues for detailed exploration of physical and chemical properties in various scientific applications.
PubMed: 38882160
DOI: 10.1021/acsomega.4c01197 -
Langmuir : the ACS Journal of Surfaces... Mar 2024Amphiphilic diblock copolymers containing a block of 2-methacryloyloxyethyl phosphorylcholine (MPC) with unique properties to prevent nonspecific protein adsorption and...
Amphiphilic diblock copolymers containing a block of 2-methacryloyloxyethyl phosphorylcholine (MPC) with unique properties to prevent nonspecific protein adsorption and enhance lubrication in aqueous media and a block of dopamine methacrylamide (DOPMA) distinguished by excellent adhesion performance were synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization for the first time. The DOPMA monomer with an acetonide-protected catechol group (acetonide-protected dopamine methacrylamide (ADOPMA)) was used, allowing the prevention of undesirable side reactions during polymerization and oxidation during storage. The adsorption behavior of the diblock copolymers with protected and unprotected catechol groups on gold surfaces was probed using attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectroscopy, surface-enhanced infrared absorption spectroscopy (SEIRAS), and reflection-absorption infrared spectroscopy (RAIRS). The copolymers pMPC--pADOPMA demonstrated physisorption with rapid adsorption and ultrasound-assisted desorption, while the copolymers pMPC--DOPMA exhibited chemical adsorption with slower dynamics but a stronger interaction with the gold surface. SEIRAS and RAIRS allowed proving the reorientation of the diblock copolymers during adsorption, demonstrating the exposure of the pMPC block toward the aqueous phase.
PubMed: 38456424
DOI: 10.1021/acs.langmuir.3c03925