Structural adaptability and surface activity of peptides derived from tardigrade proteins.

Tardigrades are unique micro-organisms with a high tolerance to desiccation. The protection of their cells against desiccation involves tardigrade-specific proteins, which include the so-called cytoplasmic abundant heat soluble (CAHS) proteins. As a first step towards the design of peptides capable of mimicking the cytoprotective properties of CAHS proteins, we have synthesized several model peptides with sequences selected from conserved CAHS motifs and investigated to what extent they exhibit the desiccation-induced structural changes of the full-length proteins. Using circular dichroism spectroscopy, two-dimensional infrared spectroscopy, and molecular dynamics simulations, we have found that the CAHS model peptides are mostly disordered, but adopt a more α $$ \alpha $$ -helical structure upon addition of 2,2,2-trifluoroethanol, which mimics desiccation. This structural behavior is similar to that of full-length CAHS proteins, which also adopt more ordered conformations upon desiccation. We also have investigated the surface activity of the peptides at the air/water interface, which also mimics partial desiccation. Interestingly, sum-frequency generation spectroscopy shows that all model peptides are surface active and adopt a helical structure at the air/water interface. Our results suggest that amino acids with high helix-forming propensities might contribute to the propensity of these peptides to adopt a helical structure when fully or partially dehydrated. Thus, the selected sequences retain part of the CAHS structural behavior upon desiccation, and might be used as a basis for the design of new synthetic peptide-based cryoprotective materials.

Hierarchical Protofilament Intertwining Rules the Formation of Mixed-Curvature Amyloid Polymorphs.

Amyloid polymorphism is a hallmark of almost all amyloid species, yet the mechanisms underlying the formation of amyloid polymorphs and their complex architectures remain elusive. Commonly, two main mesoscopic topologies are found in amyloid polymorphs characterized by non-zero Gaussian and mean curvatures: twisted ribbons and helical fibrils, respectively. Here, a rich heterogeneity of configurations is demonstrated on insulin amyloid fibrils, where protofilament packing can occur, besides the common polymorphs, also in a combined mode forming mixed-curvature polymorphs. Through AFM statistical analysis, an extended array of heterogeneous architectures that are rationalized by mesoscopic theoretical arguments are identified. Notably, an unusual fibrillization pathway is also unraveled toward mixed-curvature polymorphs via the widespread recruitment and intertwining of protofilaments and protofibrils. The results present an original view of amyloid polymorphism and advance the fundamental understanding of the fibrillization mechanism from single protofilaments into mature amyloid fibrils.

Approaching fertility in congenital adrenal hyperplasia: exploring P30L mutation-induced 21-hydroxylase deficiency with a presentation between non-classical and simple virilizing phenotypes. A case report.

Congenital adrenal hyperplasia (CAH) is determined in the vast majority of cases by mutations in the CYP21A2 gene, which cause the deficiency of the 21 hydroxylase enzyme, which is involved in the synthesis of cortisol and aldosterone. Generally, CAH phenotype and disease severity can be predicted with the genotypes and is related to the residual activity of 21 hydroxylase enzyme. It is divided into classical CAH with salt wasting and simple virilizing forms and non-classical or late-onset CAH forms, respectively. Patients with 21 hydroxylase deficiency, including those with non-classic forms face immense challenges to their fertility. Glucocorticoid therapy has been shown to be useful in obtaining and maintaining a pregnancy among these patients, but it must be used with caution. Given the relevance of CAH in reproductive medicine as well as the diagnostic challenges posed by the phenotypic overlap with polycystic ovary syndrome and by overlap of its own phenotypes (classic CAH-nonclassic CAH), we present the case of a woman with CAH due to 21 hydroxylase deficiency caused by the P30L mutation with a clinical and biochemical presentation between the non-classical form and the classic simple virilizing form. Further, the successful fertility management in this patient and an overview of fertility management in CAH is depicted, as well.

Elucidating the role of water in collagen self-assembly by isotopically modulating collagen hydration.

Water is known to play an important role in collagen self-assembly, but it is still largely unclear how water-collagen interactions influence the assembly process and determine the fibril network properties. Here, we use the H[Formula: see text]O/D[Formula: see text]O isotope effect on the hydrogen-bond strength in water to investigate the role of hydration in collagen self-assembly. We dissolve collagen in H[Formula: see text]O and D[Formula: see text]O and compare the growth kinetics and the structure of the collagen assemblies formed in these water isotopomers. Surprisingly, collagen assembly occurs ten times faster in D[Formula: see text]O than in H[Formula: see text]O, and collagen in D[Formula: see text]O self-assembles into much thinner fibrils, that form a more inhomogeneous and softer network, with a fourfold reduction in elastic modulus when compared to H[Formula: see text]O. Combining spectroscopic measurements with atomistic simulations, we show that collagen in D[Formula: see text]O is less hydrated than in H[Formula: see text]O. This partial dehydration lowers the enthalpic penalty for water removal and reorganization at the collagen-water interface, increasing the self-assembly rate and the number of nucleation centers, leading to thinner fibrils and a softer network. Coarse-grained simulations show that the acceleration in the initial nucleation rate can be reproduced by the enhancement of electrostatic interactions. These results show that water acts as a mediator between collagen monomers, by modulating their interactions so as to optimize the assembly process and, thus, the final network properties. We believe that isotopically modulating the hydration of proteins can be a valuable method to investigate the role of water in protein structural dynamics and protein self-assembly.

Binding Dynamics of a Stapled Peptide Targeting the Transcription Factor NF-Y.

Transcription factors (TFs) play a central role in gene regulation, and their malfunction can result in a plethora of severe diseases. TFs are therefore interesting therapeutic targets, but their involvement in protein-protein interaction networks and the frequent lack of well-defined binding pockets render them challenging targets for classical small molecules. As an alternative, peptide-based scaffolds have proven useful, in particular with an α-helical active conformation. Peptide-based strategies often require extensive structural optimization efforts, which could benefit from a more detailed understanding of the dynamics in inhibitor/protein interactions. In this study, we investigate how truncated stapled α-helical peptides interact with the transcription factor Nuclear Factor-Y (NF-Y). We identified a 13-mer minimal binding core region, for which two crystal structures with an altered C-terminal peptide conformation when bound to NF-Y were obtained. Subsequent molecular dynamics simulations confirmed that the C-terminal part of the stapled peptide is indeed relatively flexible while still showing defined interactions with NF-Y. Our findings highlight the importance of flexibility in the bound state of peptides, which can contribute to overall binding affinity.

Unlocking novel therapies: cyclic peptide design for amyloidogenic targets through synergies of experiments, simulations, and machine learning.

Existing therapies for neurodegenerative diseases like Parkinson's and Alzheimer's address only their symptoms and do not prevent disease onset. Common therapeutic agents, such as small molecules and antibodies struggle with insufficient selectivity, stability and bioavailability, leading to poor performance in clinical trials. Peptide-based therapeutics are emerging as promising candidates, with successful applications for cardiovascular diseases and cancers due to their high bioavailability, good efficacy and specificity. In particular, cyclic peptides have a long in vivo stability, while maintaining a robust antibody-like binding affinity. However, the de novo design of cyclic peptides is challenging due to the lack of long-lived druggable pockets of the target polypeptide, absence of exhaustive conformational distributions of the target and/or the binder, unknown binding site, methodological limitations, associated constraints (failed trials, time, money) and the vast combinatorial sequence space. Hence, efficient alignment and cooperation between disciplines, and synergies between experiments and simulations complemented by popular techniques like machine-learning can significantly speed up the therapeutic cyclic-peptide development for neurodegenerative diseases. We review the latest advancements in cyclic peptide design against amyloidogenic targets from a computational perspective in light of recent advancements and potential of machine learning to optimize the design process. We discuss the difficulties encountered when designing novel peptide-based inhibitors and we propose new strategies incorporating experiments, simulations and machine learning to design cyclic peptides to inhibit the toxic propagation of amyloidogenic polypeptides. Importantly, these strategies extend beyond the mere design of cyclic peptides and serve as template for the de novo generation of (bio)materials with programmable properties.

Decrypting Integrins by Mixed-Solvent Molecular Dynamics Simulations.

Integrins are a family of α/ß heterodimeric cell surface adhesion receptors which are capable of transmitting signals bidirectionally across membranes. They are known for their therapeutic potential in a wide range of diseases. However, the development of integrin-targeting medications has been impacted by unexpected downstream effects including unwanted agonist-like effects. Allosteric modulation of integrins is a promising approach to potentially overcome these limitations. Applying mixed-solvent molecular dynamics (MD) simulations to integrins, the current study uncovers hitherto unknown allosteric sites within the integrin α I domains of LFA-1 (αLß2; CD11a/CD18), VLA-1 (α1ß1; CD49a/CD29), and Mac-1 (αMß2, CD11b/CD18). We show that these pockets are putatively accessible to small-molecule modulators. The findings reported here may provide opportunities for the design of novel allosteric integrin inhibitors lacking the unwanted agonism observed with earlier as well as current integrin-targeting drugs.

Immunotherapy in Gastroenteropancreatic Neuroendocrine Neoplasia.

The worldwide prevalence and incidence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) and of NENs, in general, have been increasing recently. While valuing the considerable progress made in the treatment strategies for GEP-NEN in recent years, patients with advanced, metastasized disease still have a poor prognosis, which calls for urgent novel therapies. The immune system plays a dual role: both host-protecting and "tumor-promoting." Hence, immunotherapy is potentially a powerful weapon to help NEN patients. However, although recent successes with checkpoint inhibitors have shown that enhancing antitumor immunity can be effective, the dynamic nature of the immunosuppressive tumor microenvironment presents significant hurdles to the broader application of these therapies. Studies led to their approval in NEN of the lung and Merkel cell carcinoma, whereas results in other settings have not been so encouraging. Oncolytic viruses can selectively infect and destroy cancer cells, acting as an in situ cancer vaccine. Moreover, they can remodel the tumor microenvironment toward a T cell-inflamed phenotype. Oncolytic virotherapy has been proposed as an ablative and immunostimulatory treatment strategy for solid tumors that are resistant to checkpoint inhibitors alone. Future efforts should focus on finding the best way to include immunotherapy in the GEP-NEN treatment scenario. In this context, this study aims at providing a comprehensive generalized review of the immune checkpoint blockade and the oncolytic virotherapy use in GEP-NENs that might improve GEP-NEN treatment strategies.

Interactions of Curcumin's Degradation Products with the Aß42 Dimer: A Computational Study.

Amyloid-ß (Aß) dimers are the smallest toxic species along the amyloid-aggregation pathway and among the most populated oligomeric accumulations present in the brain affected by Alzheimer's disease (AD). A proposed therapeutic strategy to avoid the aggregation of Aß into higher-order structures is to develop molecules that inhibit the early stages of aggregation, i.e., dimerization. Under physiological conditions, the Aß dimer is highly dynamic and does not attain a single well-defined structure but is rather characterized by an ensemble of conformations. In a recent study, a highly heterogeneous library of conformers of the Aß dimer was generated by an efficient sampling method with constraints based on ion mobility mass spectrometry data. Here, we make use of the Aß dimer library to study the interaction with two curcumin degradation products, ferulic aldehyde and vanillin, by molecular dynamics (MD) simulations. Ensemble docking and MD simulations are used to provide atomistic detail of the interactions between the curcumin degradation products and the Aß dimer. The simulations show that the aromatic residues of Aß, and in particular 19FF20, interact with ferulic aldehyde and vanillin through π-π stacking. The binding of these small molecules induces significant changes on the 16KLVFF20 region.

Enhancing Metformin Effects by Adding Gut Microbiota Modulators to Ameliorate the Metabolic Status of Obese, Insulin-Resistant Hosts.

Obesity is a systemic disease and represents one of the leading causes of death worldwide by constituting the main risk factor for a series of non-communicable diseases such as type 2 diabetes mellitus (T2DM), cardiovascular diseases and dyslipidemia. Lifestyle interventions have been attempting to prevent T2DM and obesity but are difficult to maintain by most patients. However, the recent focus on the intestinal microbiota and its important role in the host's metabolism provides a new key for improving metabolic health. Modulating the composition of the gut microbiota was proposed as a method to manage these metabolic diseases and most frequently this is undertaken by using probiotics, prebiotics or synbiotics. Furthermore, the action of metformin, the most commonly prescribed drug for treating T2DM, is mediated in part by the gut microbiota, although this interplay may also be responsible for the frequent gastrointestinal adverse effects of metformin. Thus, adding a gut microbiota modulator (GMM), such as probiotics or prebiotics, to metformin therapy could amplify its anti-diabetic effects, while decreasing its adverse reactions. This review summarizes the various therapies that are used to shift the composition of the microbiome and their efficacy in alleviating metabolic parameters, it assesses the interaction between metformin and the gut microbiota, and it evaluates the existing clinical and preclinical studies that analyze the potential synergy of a combined metformin-GMM therapy.

Antibody binding increases the flexibility of the prion protein.

Prion diseases are associated with the conversion of the cellular prion protein (PrP) into a pathogenic conformer (PrPSc). A proposed therapeutic approach to avoid the pathogenic transformation is to develop antibodies that bind to PrP and stabilize its structure. POM1 and POM6 are two monoclonal antibodies that bind the globular domain of PrP and have different biological responses, i.e., trigger neurotoxicity mimicking prion infections (POM1) or prevent neurotoxicity (POM6). The crystal structures of PrP in complex with the two antibodies show similar epitopes which seems inconsistent with the opposite phenotypes. Here, we investigate the influence of the POM1 and POM6 antibodies on the flexibility of the mouse PrP by molecular dynamics simulations. The simulations reveal that the POM6/PrP interface is less stable than the POM1/PrP interface, ascribable to localized polar mismatches at the interface, despite the former complex having a larger epitope than the latter. In the presence of any of the two antibodies, the flexibility of the globular domain increases everywhere except for the ß1-α1 loop in the POM1/PrP complex which suggests the involvement of this loop in the pathological conversion. The secondary structure of PrP is preserved whereas the polar interactions involving residues Glu146, Arg156 and Arg208 are modified upon antibody binding.

Antibody binding modulates the dynamics of the membrane-bound prion protein.

Misfolding of the cellular prion protein (PrPC) is associated with lethal neurodegeneration. PrPC consists of a flexible tail (residues 23-123) and a globular domain (residues 124-231) whose C-terminal end is anchored to the cell membrane. The neurotoxic antibody POM1 and the innocuous antibody POM6 recognize the globular domain. Experimental evidence indicates that POM1 binding to PrPC emulates the influence on PrPC of the misfolded prion protein (PrPSc) while the binding of POM6 has the opposite biological response. Little is known about the potential interactions between flexible tail, globular domain, and the membrane. Here, we used atomistic simulations to investigate how these interactions are modulated by the binding of the Fab fragments of POM1 and POM6 to PrPC and by interstitial sequence truncations to the flexible tail. The simulations show that the binding of the antibodies restricts the range of orientations of the globular domain with respect to the membrane and decreases the distance between tail and membrane. Five of the six sequence truncations influence only marginally this distance and the contact patterns between tail and globular domain. The only exception is a truncation coupled to a charge inversion mutation of four N-terminal residues, which increases the distance of the flexible tail from the membrane. The interactions of the flexible tail and globular domain are modulated differently by the two antibodies.

Silybins inhibit human IAPP amyloid growth and toxicity through stereospecific interactions.

Type 2 Diabetes is a major public health threat, and its prevalence is increasing worldwide. The abnormal accumulation of islet amyloid polypeptide (IAPP) in pancreatic ß-cells is associated with the onset of the disease. Therefore, the design of small molecules able to inhibit IAPP aggregation represents a promising strategy in the development of new therapies. Here we employ in vitro, biophysical, and computational methods to inspect the ability of Silybin A and Silybin B, two natural diastereoisomers extracted from milk thistle, to interfere with the toxic self-assembly of human IAPP (hIAPP). We show that Silybin B inhibits amyloid aggregation and protects INS-1 cells from hIAPP toxicity more than Silybin A. Molecular dynamics simulations revealed that the higher efficiency of Silybin B is ascribable to its interactions with precise hIAPP regions that are notoriously involved in hIAPP self-assembly i.e., the S20-S29 amyloidogenic core, H18, the N-terminal domain, and N35. These results highlight the importance of stereospecific ligand-peptide interactions in regulating amyloid aggregation and provide a blueprint for future studies aimed at designing Silybin derivatives with enhanced drug-like properties.

The role of the N-terminal amphipathic helix in bacterial YidC: Insights from functional studies, the crystal structure and molecular dynamics simulations.

The evolutionary conserved YidC is a unique dual-function membrane protein that adopts insertase and chaperone conformations. The N-terminal helix of Escherichia coli YidC functions as an uncleaved signal sequence and is important for membrane insertion and interaction with the Sec translocon. Here, we report the first crystal structure of Thermotoga maritima YidC (TmYidC) including the N-terminal amphipathic helix (N-AH) (PDB ID: 6Y86). Molecular dynamics simulations show that N-AH lies on the periplasmic side of the membrane bilayer forming an angle of about 15° with the membrane surface. Our functional studies suggest a role of N-AH for the species-specific interaction with the Sec translocon. The reconstitution data and the superimposition of TmYidC with known YidC structures suggest an active insertase conformation for YidC. Molecular dynamics (MD) simulations of TmYidC provide evidence that N-AH acts as a membrane recognition helix for the YidC insertase and highlight the flexibility of the C1 region underlining its ability to switch between insertase and chaperone conformations. A structure-based model is proposed to rationalize how YidC performs the insertase and chaperone functions by re-positioning of N-AH and the other structural elements.

Thermostable designed ankyrin repeat proteins (DARPins) as building blocks for innovative drugs.

Designed ankyrin repeat proteins (DARPins) are antibody mimetics with high and mostly unexplored potential in drug development. By using in silico analysis and a rationally guided Ala scanning, we identified position 17 of the N-terminal capping repeat to play a key role in overall protein thermostability. The melting temperature of a DARPin domain with a single full-consensus internal repeat was increased by 8 °C to 10 °C when Asp17 was replaced by Leu, Val, Ile, Met, Ala, or Thr. We then transferred the Asp17Leu mutation to various backgrounds, including clinically validated DARPin domains, such as the vascular endothelial growth factor-binding domain of the DARPin abicipar pegol. In all cases, these proteins showed improvements in the thermostability on the order of 8 °C to 16 °C, suggesting the replacement of Asp17 could be generically applicable to this drug class. Molecular dynamics simulations showed that the Asp17Leu mutation reduces electrostatic repulsion and improves van-der-Waals packing, rendering the DARPin domain less flexible and more stable. Interestingly, this beneficial Asp17Leu mutation is present in the N-terminal caps of three of the five DARPin domains of ensovibep, a SARS-CoV-2 entry inhibitor currently in clinical development, indicating this mutation could be partly responsible for the very high melting temperature (>90 °C) of this promising anti-COVID-19 drug. Overall, such N-terminal capping repeats with increased thermostability seem to be beneficial for the development of innovative drugs based on DARPins.

Spontaneous remission of Cushing's disease: A systematic review.

Spontaneous remission is rare in Cushing's disease. We describe one illustrative case and provide a systematic review of cases previously reported in the literature. Case report: A 51-year-old woman diagnosed with Cushing's disease underwent 9 months' isolated metyrapone treatment. Two months after end of treatment, she was admitted with acute kidney failure. After another 4 months, in June 2020, there was no evidence of hypercortisolism, either clinically or biochemically, or of hypocortisolism. At the time of writing, 1 year later, she was still in remission. Cases reported in the literature: 23 patients were reported, including the present case. 87% were female with a median age of 32 years. Ten of those with radiologically visible tumors had microadenoma (44%) and 7 had macroadenoma (30%). Mean time from diagnosis to spontaneous remission was 5 months, and was shorter in macroadenoma (1 month) than in microadenoma (13.5 months). Treatments before spontaneous remission were: no treatment (65%), steroidogenesis enzyme inhibitors (22%), bilateral adrenalectomy and adrenal autotransplantation (5%), partial bilateral adrenalectomy (4%), and incomplete pituitary surgery (4%). Pituitary tumor apoplexy was the most frequently incriminated event (91%), radiologically documented in 43% of patients. Mean remission during follow-up was 28 months (range, 6-130 months). Recurrence occurred in 39% (n=9) of patients. Although several mechanisms responsible for this phenomenon have been proposed, clinical or subclinical pituitary tumor apoplexy, the latter sometimes presenting atypically, seems to be the most frequently incriminated event. Doctors should be aware of this, and regular follow-up is mandatory due to its unpredictability.

Flanking sequence preference modulates de novo DNA methylation in the mouse genome.

Mammalian de novo DNA methyltransferases (DNMT) are responsible for the establishment of cell-type-specific DNA methylation in healthy and diseased tissues. Through genome-wide analysis of de novo methylation activity in murine stem cells we uncover that DNMT3A prefers to methylate CpGs followed by cytosines or thymines, while DNMT3B predominantly methylates CpGs followed by guanines or adenines. These signatures are further observed at non-CpG sites, resembling methylation context observed in specialised cell types, including neurons and oocytes. We further show that these preferences result from structural differences in the catalytic domains of the two de novo DNMTs and are not a consequence of differential recruitment to the genome. Molecular dynamics simulations suggest that, in case of human DNMT3A, the preference is due to favourable polar interactions between the flexible Arg836 side chain and the guanine that base-pairs with the cytosine following the CpG. By exchanging arginine to a lysine, the corresponding side chain in DNMT3B, the sequence preference is reversed, confirming the requirement for arginine at this position. This context-dependent enzymatic activity provides additional insights into the complex regulation of DNA methylation patterns.

MicroRNAs and Treatment with Somatostatin Analogs in Gastro- Entero-Pancreatic Neuroendocrine Neoplasms: Challenges in Personalized Medicine.

Molecular predictive biomarkers represent an essential tool for the future of personalized oncotherapy. Gastro- entero-pancreatic neuroendocrine neoplasms are a heterogeneous group of epithelial tumors with a steady increase in incidence and prevalence. Their effective management depends on early diagnosis, personalized risk stratification, and monitoring response to therapy. A crucial element is identifying accurate biomarkers to predict/monitor therapeutic responses, assess drug resistance, and quantify residual disease in a reproducible and less invasive way. Taking into consideration their role in cell differentiation, cell proliferation, apoptosis and tumor development, microRNAs have gained interest as potential prognostic markers and treatment response predictors in neuroendocrine neoplasms. This review is the first to summarize the available data on the possible role of microRNAs in evaluating the efficacy of somatostatin analogs treatment in gastro- entero-pancreatic neuroendocrine neoplasms. Although the literature is scarce, the let-7 family targeting phosphoinositide 3 kinase - protein kinase B 1 - mammalian target of rapamycin signaling pathway might represent a promising biomarker with potential clinical benefit, but further research is required before their eventual clinical application. Furthermore, the ambiguous molecular mechanisms of neuroendocrine proliferation and the undefined signaling pathway of somatostatin analogs should encourage future research in this field that may lead to a different clinical approach to neuroendocrine disease.

Neurotransmitter, neuropeptide and gut peptide profile in PCOS-pathways contributing to the pathophysiology, food intake and psychiatric manifestations of PCOS.

Polycystic ovary syndrome (PCOS) is a major health problem with a heterogeneous hormone-imbalance and clinical presentation across the lifespan of women. Increased androgen production and abnormal gonadotropin-releasing hormone (GnRH) release and gonadotropin secretion, resulting in chronic anovulation are well-known features of the PCOS. The brain is both at the top of the neuroendocrine axis regulating ovarian function and a sensitive target of peripheral gonadal hormones and peptides. Current literature illustrates that neurotransmitters regulate various functions of the body, including reproduction, mood and body weight. Neurotransmitter alteration could be one of the reasons for disturbed GnRH release, consequently directing the ovarian dysfunction in PCOS, since there is plenty evidence for altered catecholamine metabolism and brain serotonin or opioid activity described in PCOS. Further, the dysregulated neurotransmitter and neuropeptide profile in PCOS could also be the reason for low self-esteem, anxiety, mood swings and depression or obesity, features closely associated with PCOS women. Can these altered central brain circuits, or the disrupted gut-brain axis be the tie that would both explain and link the pathogenesis of this disorder, the occurrence of depression, anxiety and other mood disorders as well as of obesity, insulin resistance and abnormal appetite in PCOS? This review intends to provide the reader with a comprehensive overview of what is known about the relatively understudied, but very complex role that neurotransmitters, neuropeptides and gut peptides play in PCOS. The answer to the above question may help the development of drugs to specifically target these central and peripheral circuits, thereby providing a valuable treatment for PCOS patients that present to the clinic with GnRH/LH hypersecretion, obesity or psychiatric manifestations.

Lipidomics biomarkers in women with polycystic ovary syndrome (PCOS) using ultra-high performance liquid chromatography-quadrupole time of flight electrospray in a positive ionization mode mass spectrometry.

Polycystic ovary syndrome (PCOS), characterized by oligo-anovulation and androgen excess is considered a high-risk condition for metabolic disorders. Herein, untargeted metabolomics analysis was applied to women with PCOS, aiming to provide deeper insights into lipidomics biomarkers signature of PCOS, for better diagnosis and management. This was a cross-sectional study in which 15 Caucasian women with PCOS and 15 Caucasian healthy, age-matched women were enrolled. Lipidomics analysis was performed using Ultra-High Performance Liquid Chromatography-Quadrupole Time of Flight Electrospray Mass Spectrometry. Partial Least Squares Discriminant Analysis retrieved the most important discriminative metabolites. Significantly increased levels of triacylglycerol (18:2/18:2/0-18:0) in addition to cholestane-3beta, 5alpha, 6beta-triol (18:0/0:0) and cholestane-5alpha (18:1/0:0) appeared as valuable variables to differentiate subjects with PCOS from controls. Acyl-carnitine 2-hydroxylauroylcarnitine was significantly elevated in PCOS in opposition to decreased phosphocholines metabolites (18:1/18:4, 18:3/18:2), to suggest a metabolic pattern linked to lipid peroxidation. A high fat intake or reduced fat energy consumption during nighttime due to diminished ability to switch to lipid oxidation during fasting time possibly contribute to hypertriglyceridemia found in PCOS. Furthermore, inflammatory mediators including metabolites of the prostaglandin (PG) E2 pathway and oxo-leukotrienes (LT) were increased in patients with PCOS. Potential lipidomics biomarkers were identified that could stratify between women with PCOS and healthy controls. The results show particular alterations in acylglycerols, PGs and LTs and phosphocholines and carnitine metabolites. The lipidomics profiles of PCOS indicate a higher risk of developing metabolic diseases.