P–591 Mass spectrometry-based glycomic profiling of the follicular fluid total immunoglobulin G and proteome N-glycomes reveals deregulated inflammatory processes associated with specific controlled ovarian stimulation protocols

Study question Is there a significant inflammatory-related difference between analyzed follicular fluid (FF) glycome profiles regarding the ovarian stimulation protocol used in patients? Summary answer Observed differences between analyzed glycome profiles from patients that underwent different controlled ovarian stimulation (COS) protocols point to deregulated inflammatory processes associated with specific COS. What is known already Successful physiological folliculogenesis and ovulation require an adequate inflammatory response. On the other hand, COS application in ART relies on induced hormonal activation of systemic inflammatory processes. Several studies have confirmed a rise in inflammatory cytokines, CRP, and other markers of inflammation in patients subjected to different COS protocols, pointing to an enhanced inflammatory response during ovulation stimulation. Glycoproteins and glycans have an indisputable role in immune response modulation: proper glycosylation of glycoproteins plays a pivotal role in the regulation of normal physiological processes, and aberrant glycosylation of glycoproteins has been associated with various pathological states, including inflammation. Study design, size, duration Study design: Cross sectional – FFs from patients that underwent ART in modified natural cycle (MNC group) versus FFs from patients that underwent ART under GnRH antagonist COS (COS group). Size: 20 FFs from 20 patients undergoing ART. Duration: One year. Sampling procedure: Each FF was aspirated from the dominant follicle. In the COS group, only the fluid from the first aspirated follicle of each patient was collected. Participants/materials, setting, methods Study included 20 FF samples from 20 patients divided into two groups according to the applied ovarian stimulation protocol: MNC group (n = 10) and COS group (n = 10). The immunoglobulin G (IgG) was isolated from FF samples by immunoaffinity chromatography. The N-linked glycans derived from IgG molecule and the remaining FF total proteomes were enzymatically cleaved and subjected to derivatization procedure. N-glycomes of FF-isolated IgG and total proteomes were analyzed separately by MALDI-TOF-MS. Main results and the role of chance FF IgG N-glycome profiling The MALDI-TOF-MS based comparative analysis of the individual glycan relative abundances, revealed several significantly deregulated glycoforms between analyzed groups whose levels were significantly elevated (p˂0.05) in the COS vs. MNC group. Furthermore, additional low abundant N-glycan species were also found to be deregulated between the analyzed groups: two monogalactolysed and monosialylated N-glycan compositions were only identified in the COS group. The comparative analysis of FF IgG N-glycome features revealed statistically relevant differences in the levels of two derived traits: galactosylation and bigalactosylation levels of the FF IgG N-glycome, both significantly downregulated (p˂0.05) in the MNC vs. COS profile. Comparative analysis of FF total proteome N-glycome The majority of identified glycan compositions were complex type N-glycans representing more than 98% of the total N-glycome profiles in both analyzed groups. The comparative analysis of individual glycan relative abundances revealed relevant differences in regulation of ten N-glycan species between the two analyzed profiles. In the MNC group, six N-glycan species showed significantly increased abundances (p˂0.05) compared with the COS group. Moreover, two compositions were exclusively identified in the MNC group, while two compositions were identified only in the COS group. Limitations, reasons for caution Since this preliminary study was conducted on relatively small sample size, all results should be verified on a larger sample set. Moreover, focused glycosylation analysis of a panel of individual FF acute phase blood serum derived proteins and immunoglobulins, might additionally clarify the inflammatory mechanisms underlying different ART stimulation protocols. Wider implications of the findings: While glycome profiling of human FFs was conducted for the first time, previous evidence supports the shown association of aberrant inflammation in diverse ART stimulation protocols and in development of various pathological states (i.e. OHSS). Obtained results are in line with previous similar studies performed in the human plasma. Trial registration number uniri-biomed–18–161 1310

Understanding The Structure And Composition of Recalcitrant Oligosaccharides In Ammonia Treated Lignocellulosic Biomass Hydrolysate Using High-Throughput Biotin- Based Glycome Profiling And Mass Spectrometry.

Novel Immunological and Mass Spectrometry Methods for Comprehensive Analysis of Recalcitrant Oligosaccharides in AFEX Pretreated Corn Stover Lignocellulosic biomass is a sustainable alternative to fossil fuel and is extensively used for developing bio-based technologies to produce products such as food, feed, fuel, and chemicals. The key to these technologies is to develop cost competitive processes to convert complex carbohydrates present in plant cell wall to simple sugars such as glucose, xylose and arabinose. Since lignocellulosic biomass is highly recalcitrant, it must undergo a combination of thermochemical treatment such as Ammonia Fiber Expansion (AFEX), dilute acid (DA), Ionic Liquid (IL) and biological treatment such as enzyme hydrolysis and microbial fermentation to produce desired products. However, when using commercial fungal enzymes during hydrolysis, only 75-85% of the soluble sugars generated are monomeric sugars, while the remaining 15-25% are soluble recalcitrant oligosaccharides that cannot be easily utilized by microorganisms. Previously, we successfully separated and purified the soluble recalcitrant oligosaccharides using a combination of charcoal and celite-based separation followed by size exclusion chromatography and studies their inhibitory properties on enzymes. We discovered that the oligosaccharides with higher degree of polymerization (DP) containing methylated uronic acid substitutions were more recalcitrant towards commercial enzyme mixtures than lower DP and neutral oligosaccharides. Here, we report the use of several complementary techniques that include glycome profiling using plant biomass glycan specific monoclonal antibodies (mAbs) to characterize sugar linkages in plant cell walls and enzymatic hydrolysate, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) using structurally-informative diagnostic peaks offered by negative ion post-secondary decay spectra, gas chromatography followed by mass spectrometry (GC-MS) to characterize oligosaccharide sugar linkages with and without derivatization. Since oligosaccharides (DP 4-20) are small, it is challenging to immobilize these molecules for mAbs binding and characterization. To overcome this problem, we have developed a new biotin-coupling based oligosaccharide immobilization method that successfully tagged most of the low DP soluble oligosaccharides on to a micro-plate surface followed by specific linkage analysis using mAbs in a high-throughput system. This new approach will help develop more advanced versions of future high throughput glycome profiling methods that can be used to separate and characterize oligosaccharides present in biomarkers for diagnostic applications.

Arabidopsis cell wall composition determines disease resistance specificity and fitness

Plant cell walls are complex structures subject to dynamic remodeling in response to developmental and environmental cues and play essential functions in disease resistance responses. We tested the specific contribution of plant cell walls to immunity by determining the susceptibility of a set of Arabidopsis cell wall mutants (cwm) to pathogens with different parasitic styles: a vascular bacterium, a necrotrophic fungus, and a biotrophic oomycete. Remarkably, most cwm mutants tested (29/34; 85.3%) showed alterations in their resistance responses to at least one of these pathogens in comparison to wild-type plants, illustrating the relevance of wall composition in determining disease-resistance phenotypes. We found that the enhanced resistance of cwm plants to the necrotrophic and vascular pathogens negatively impacted cwm fitness traits, such as biomass and seed yield. Enhanced resistance of cwm plants is not only mediated by canonical immune pathways, like those modulated by phytohormones or microbe-associated molecular patterns, which are not deregulated in the cwm tested. Pectin-enriched wall fractions isolated from cwm plants triggered immune responses in wild-type plants, suggesting that wall-mediated defensive pathways might contribute to cwm resistance. Cell walls of cwm plants show a high diversity of composition alterations as revealed by glycome profiling that detect specific wall carbohydrate moieties. Mathematical analysis of glycome profiling data identified correlations between the amounts of specific wall carbohydrate moieties and disease resistance phenotypes of cwm plants. These data support the relevant and specific function of plant wall composition in plant immune response modulation and in balancing disease resistance/development trade-offs.

Arabidopsis cell wall composition determines disease resistance specificity and fitness

Plant cell walls are complex structures subject to dynamic remodeling in response to developmental and environmental cues, and play essential functions in disease resistance responses. We tested the specific contribution of plant cell walls to immunity by determining the susceptibility of a set of Arabidopsis cell wall mutants (cwm) to pathogens with different parasitic styles: a vascular bacterium, a necrotrophic fungus and a biotrophic oomycete. Remarkably, most cwm mutants tested (31/38; 81.6%) showed alterations in their resistance responses to at least one of these pathogens, in comparison to wild-type plants, illustrating the relevance of wall composition in determining disease resistance phenotypes. We found that the enhanced resistance of cwm plants to the necrotrophic and vascular pathogens negatively impacted on cwm fitness traits, like biomass and seed yield. Enhanced resistance of cwm plants is not only mediated by canonical immune pathways, like those modulated by phytohormones or Microbe-Associated Molecular Patterns, which are not de-regulated in all cwm tested. Pectin-enriched wall fractions isolated from cwm plants triggered immune responses in other plants, suggesting that wall-mediated defensive pathways might contribute to cwm resistance. Cell walls of cwm plants show a high diversity of composition alterations as revealed by glycome profiling that detect specific wall carbohydrate moieties. Mathematical analysis of glycome profiling data identified correlations between the amounts of specific wall carbohydrate moieties and disease resistance phenotypes of cwm plants. These data support the relevant and specific function of plant wall composition in plant immune response modulation and in balancing disease resistance/development trade-offs.

The schizophrenia risk locus in SLC39A8 alters brain metal transport and plasma glycosylation

A common missense variant in SLC39A8 is convincingly associated with schizophrenia and several additional phenotypes. Homozygous loss-of-function mutations in SLC39A8 result in undetectable serum manganese (Mn) and a Congenital Disorder of Glycosylation (CDG) due to the exquisite sensitivity of glycosyltransferases to Mn concentration. Here, we identified several Mn-related changes in human carriers of the common SLC39A8 missense allele. Analysis of structural brain MRI scans showed a dose-dependent change in the ratio of T2w to T1w signal in several regions. Comprehensive trace element analysis confirmed a specific reduction of only serum Mn, and plasma protein N-glycome profiling revealed reduced complexity and branching. N-glycome profiling from two individuals with SLC39A8-CDG showed similar but more severe alterations in branching that improved with Mn supplementation, suggesting that the common variant exists on a spectrum of hypofunction with potential for reversibility. Characterizing the functional impact of this variant will enhance our understanding of schizophrenia pathogenesis and identify novel therapeutic targets and biomarkers of disease.SummaryA common variant in the manganese transporter SLC39A8 is associated with numerous phenotypes including schizophrenia. Mealer et. al. presents an in-depth analysis of brain MRI and plasma glycomics in human carriers of the common variant, identifying several manganese-related changes with potential for diagnostic and therapeutic biomarker development.