Serum Protein Profiles Research Articles

Assessment of serum protein profile in sickle cell disease

Background: Sickle Cell disease (SCD) is known to be caused by a mutation in the beta-globin gene of the hemoglobin that affects the red blood cells (RBCs) and is passed down through generations. This study was carried out to determine the effect of sickling of RBC on serum protein profile in SCD individuals. Methods: A case-controlled study was carried out among 80 patients. They were forty-five sickle cell disease individuals (HbSS) attending Children Specialist Hospital Ilorin and thirty-five healthy controls (HbAA). The levels of total protein and albumin were determined spectrophotometrically and serum protein electrophoresis (SPE) was carried out using cellulose acetate electrophoresis. Results: Significant hypoalbuminemia and hypergammaglobulinemia were observed in SCD groups compared with controls. A higher proportion of the SCD group, 11(25%) had hypergammaglobulinemia and 21(49%) had hypoalbuminemia (P<0.05). Plasma protein electrophoresis in SCD patients shows an intense colour at the gamma region which was not seen in control. There was a significant relationship between the patterns of serum protein electrophoresis and the frequency of crisis. Conclusions: Sickle cell disease crisis and other associated underlying conditions may be prevented early through assessment of serum protein profile, especially SPE. Hypergammaglobulinemia and hypoalbuminemia may be associated with frequent episode of crisis.

Elevated serum mtDNA in COVID-19 patients is linked to SARS-CoV-2 envelope protein targeting mitochondrial VDAC1, inducing apoptosis and mtDNA release

Mitochondria dysfunction is implicated in cell death, inflammation, and autoimmunity. During viral infections, some viruses employ different strategies to disrupt mitochondria-dependent apoptosis, while others, including SARS-CoV-2, induce host cell apoptosis to facilitate replication and immune system modulation. Given mitochondrial DNAs (mtDNA) role as a pro-inflammatory damage-associated molecular pattern in inflammatory diseases, we examined its levels in the serum of COVID-19 patients and found it to be high relative to levels in healthy donors. Furthermore, comparison of serum protein profiles between healthy individuals and SARS-CoV-2-infected patients revealed unique bands in the COVID-19 patients. Using mass spectroscopy, we identified over 15 proteins, whose levels in the serum of COVID-19 patients were 4- to 780-fold higher. As mtDNA release from the mitochondria is mediated by the oligomeric form of the mitochondrial-gatekeeper—the voltage-dependent anion-selective channel 1 (VDAC1)—we investigated whether SARS-CoV-2 protein alters VDAC1 expression. Among the three selected SARS-CoV-2 proteins, small envelope (E), nucleocapsid (N), and accessory 3b proteins, the E-protein induced VDAC1 overexpression, VDAC1 oligomerization, cell death, and mtDNA release. Additionally, this protein led to mitochondrial dysfunction, as evidenced by increased mitochondrial ROS production and cytosolic Ca2+ levels. These findings suggest that SARS-CoV-2 E-protein induces mitochondrial dysfunction, apoptosis, and mtDNA release via VDAC1 modulation. mtDNA that accumulates in the blood activates the cGAS-STING pathway, triggering inflammatory cytokine and chemokine expression that contribute to the cytokine storm and tissue damage seen in cases of severe COVID-19.

Key biomarkers in type 2 diabetes patients: A systematic review.

Type 2 diabetes mellitus (T2DM) is not just a local health issue but a significant global health burden, affecting patient outcomes and clinical management worldwide. Despite the wealth of studies reporting T2DM biomarkers, there is an urgent need for a comparative review. This review aims to provide a comprehensive analysis based on the reported T2DM biomarkers and how these are linked with other conditions, such as inflammation and wound healing. A comparative review was conducted on 24 001 study participants, including 10 024 T2DM patients and 13 977 controls (CTL; age 30-90 years). Four main profiles were extracted and analysed from the clinical reports over the past 11 years: haematological (1084 cases vs. 1458 CTL), protein (6753 cases vs. 9613 CTL), cytokine (975 cases vs. 1350 CTL) and lipid (1212 cases vs. 1556 CTL). This review provides a detailed analysis of the haematological profile in T2DM patients, highlighting fundamental changes such as increased white blood cells and platelet counts, accompanied by decreases in red blood cell counts and iron absorption. In the serum protein profile, a reduction in albumin and anti-inflammatory cytokines was noted along with an increase in globulin levels and pro-inflammatory cytokines. Furthermore, changes in lipid profiles were discussed, specifically the decreases in high-density lipoprotein (HDL) and the increases in low-density lipoprotein (LDL) and triglycerides. Understanding the changes in these four biomarker profiles is essential for developing innovative strategies to create diagnostic and prognostic tools for diabetes management.

In Vivo Investigation of the Anti-Staphylococcus aureus Impact of Balanites aegyptiaca and Curcuma longa Ethanol Extracts on Apoptotic Gene Expression and Their Implications on Hemogram and Serum Protein Profiles

In Vivo Investigation of the Anti-Staphylococcus aureus Impact of Balanites aegyptiaca and Curcuma longa Ethanol Extracts on Apoptotic Gene Expression and Their Implications on Hemogram and Serum Protein Profiles

The PerioGene North Study Uncovers Serum Proteins Related to Periodontitis

The sequalae of periodontitis include irreversible degradation of tooth-supporting structures and circulatory spread of inflammatory mediators. However, the serum protein profile in periodontitis is not well described, which is partly attributable to the limited number of studies based on large and well-characterized periodontitis cohorts. This study aims to identify novel, circulating inflammation-related proteins associated with periodontitis within the PerioGene North case-control study, which includes 478 cases with severe periodontitis and 509 periodontally healthy controls. The serum concentrations of high-sensitivity C-reactive protein (hs-CRP) and a panel of 45 inflammation-related proteins were analyzed using targeted proteomics. A distinguishable serum protein profile was evident in periodontitis cases. The protein pattern could separate cases from controls with a sensitivity of 0.81 and specificity of 0.81 (area under the curve = 0.87). Adjusted levels for hs-CRP and 24 of the 45 proteins were different between cases and controls. High levels of hs-CRP and matrix metalloproteinase–12, and low levels of epidermal growth factor (EGF) and oxidized low-density lipoprotein receptor 1 (OLR-1) were detected among the cases. Furthermore, the levels of C-C motif chemokine–19, granulocyte colony-stimulating factor–3 (CSF-3), interleukin-7 (IL-7), and hs-CRP were significantly higher in cases with a high degree of gingival inflammation. The levels of CSF-3 and tumor necrosis factor ligand superfamily member–10 TNFSF-10 were higher in cases with many deep periodontal pockets. The PerioGene North study includes detailed clinical periodontal data and uncovers a distinct serum protein profile in periodontitis. The findings of lower EGF and OLR-1 among the cases are highlighted, as this has not been presented before. The role of EGF and OLR-1 in periodontitis pathogenesis and as possible future biomarkers should be further explored.

Molecular signatures of Haemonchus contortus infection in sheep: A comparative serum proteomic study on susceptible and resistant sheep breeds

Due to the negative impact of Haemonchus contortus in the tropics and subtropics, the detection of serum protein profiles that occur in infected sheep is of high relevance for targeted selective treatment strategies (TST). Herein, we integrated proteomics with phenotypic traits to elucidate physiological mechanisms associated to H. contortus infection in susceptible (Dorper – D) and resistant (Santa Inês – S) sheep breeds. Naïve female lambs were infected with H. contortus third-stage larvae on day zero (D0), and samples were collected weekly, for 28 days. Feces were used for individual fecal egg counts (FEC) blood for packed cell volume (PCV) and serum for specific antibody quantification through ELISA. Sera was collected on D0 (-) and D21 (+), and analyzed using a LC-MS/MS based proteomics approach. FEC, PCV, and anti-H. contortus antibody levels confirmed the absence of infection on D0. On D28 there was a significant difference between the two breeds for logFEC means (D = 3774 and S = 3141, p=0.033) and PCV means (D = 16.3 % and S = 24.3 %, p=0.038). From a total of 754 proteins identified, 68 differentially abundant proteins (DAPs) were noted. Phosphopyruvate hydratase (ENO3) was a DAP in all comparisons, while S+ vs D+ and S- vs D- shared the highest number of DAPs (8). Each of the four experimental groups clustered separately in a principal component analysis (PCA) of protein profile. Among the DAPs, proteins associated with the innate and adaptive immune system were detected when comparing S- vs D- and S+ vs D+. In D-, some proteins were linked to stress response to handling, sampling and heat. Focusing on the consequences of infection in each breed, in the D+ vs D- comparison, upregulated proteins were associated with inflammation control and immune response, where downregulated proteins pointed to a negative impact of infection on tissue anabolism, compromising muscle growth and fat deposition. In the S+ vs S- comparison, upregulated proteins were related to immune response, while the downregulated proteins were possibly linked to muscular development and growth, impaired by infection. Collectively, it can be concluded that ENO3 regulation emerges as a potential factor underlying the differential immune response observed between Santa Inês and Dorper sheep infected with H. contortus. In turn, detected acute phase proteins (APPs) reinforce their relation with infection, inflammation and stress conditions, whereas THEMIS-like may contribute to the immune system in Dorper. GSDMD, Guanylate-binding protein and ACAN warrant further investigation as possible biomarkers for TST strategy development.

The Potential Benefits of Acute Aronia Juice Supplementation on Physical Activity Induced Alterations of the Serum Protein Profiles in Recreational Runners: A Pilot Study.

Intensive physical activity (PA) can lead to proteinuria and, consequently, serum protein profiles in athletes. Therefore, the aim of this study was to investigate the effects of acute aronia juice consumption before a simulated half-marathon race on serum protein profiles in recreational runners. The pilot study was designed as a single-blind, placebo-controlled, crossover study, with 10 male participants who consumed aronia juice (containing 1.3 g polyphenols) or placebo before the race. The blood levels of total proteins, albumin, the non-albumin fractions gamma, beta, alpha2 and alpha1, as well as renal function parameters, were determined before and 15 min, 1 h and 24 h after the race. The significant changes in urea, creatinine and uric acid levels were noticed at selected time points in both groups. In the placebo group, a significant decrease in total proteins (p < 0.05) was observed 24 h after the race, along with an increase in gamma fraction abundance (p < 0.05). In addition, urea and uric acid levels returned to baseline only in the aronia group 24 h after the race. Thus, according to the results obtained, acute aronia juice supplementation before intensive PA could influence the transient change in renal function and PA-induced protein loss in recreational runners.

Dietary algal-sourced zinc nanoparticles promote growth performance, intestinal integrity, and immune response of Nile tilapia (Oreochromis niloticus)

BackgroundTrace elements play a crucial role in fish nutrition, with zinc (Zn) being one of the most important elements. BIO-sourced zinc nanoparticles were synthesized using the green microalga Pediastrum boryanum (BIO-ZnNPs, 29.35 nm). 30 or 60 mg/ kg dry feed of the BIO-ZnNPs (BIO-ZnNPs30 and BIO-ZnNPs60) were mixed with the Nile tilapia (Oreochromis niloticus) basal diet and fed to the fish for 8 weeks to evaluate their impact on fish growth, digestion, intestinal integrity, antioxidative status, and immunity.ResultsA significant enhancement was observed in all investigated parameters, except for the serum protein profile. BIO-ZnNPs at 60 mg/kg feed elevated the activities of reduced glutathione (GSH) and catalase (CAT), enzymatic antioxidants, but did not induce oxidative stress as reflected by no change in MDA level. Fish intestinal immunity was improved in a dose-dependent manner, in terms of improved morphometry and a higher count of acid mucin-producing goblet cells. Interleukin-8 (IL-8) was upregulated in BIO-ZnNPs30 compared to BIO-ZnNPs60 and control fish groups, while no significant expressions were noted in tumor necrosis factor-alpha (TNFα), nuclear factor kappa B (NFkB), and Caspase3 genes.ConclusionOverall, BIO-ZnNPs inclusion at 60 mg/kg feed showed the most advantage in different scenarios, compared to BIO-ZnNPs at 30 mg/kg feed. The positive effects on growth and intestinal health suggest that BIO-ZnNPs supplementation of aquafeeds has many benefits for farmed fish.

Serum protein profiling reveals mechanism of activated thrombus formation in patients with stroke and atrial fibrillation

Stroke is an acute cerebrovascular disease in which blood flow to the brain is suddenly disrupted, causing damage to nerve cells. It involves complex and diverse pathophysiological processes and the treatment strategies are also diverse. The treatment for patients with stroke and atrial fibrillation (AF) is aimed at suppressing thrombus formation and migration. However, information regarding the protein networking involved in different thrombus formation pathways in patients with AF and stroke is insufficient. We performed protein profiling of patients with ischemic stroke with and without AF to investigate the mechanisms of thrombus formation and its pathophysiological association while providing helpful information for treating and managing patients with AF. These two groups were compared to identify the protein networks related to thrombus formation in AF. We observed that patients with ischemic stroke and AF had activated inflammatory responses induced by C-reactive protein, lipopolysaccharide-binding protein, and alpha-1-acid glycoprotein 1. In contrast, thyroid hormones were increased due to a decrease in transthyretin and retinol-binding protein 4 levels. The mechanism underlying enhanced cardiac activity, vasodilation, and the resulting thrombosis pathway were confirmed in AF. These findings will play an essential role in improving the prevention and treatment of AF-related stroke.

Serum protein and imaging biomarkers after intermittent steroid treatment in muscular dystrophy.

Weekly Steroids in Muscular Dystrophy (WSiMD) was a pilot study to evaluate once weekly prednisone in patients with Limb Girdle and Becker muscular dystrophy (LGMD and BMD, respectively). At study endpoint, there were trends towards increased lean mass, reduced fat mass, reduced creatine kinase and improved motor function. The investigation was motivated by studies in mouse muscular dystrophy models in which once weekly glucocorticoid exposure enhanced muscle strength and reduced fibrosis. WSiMD participants provided blood samples for aptamer serum profiling at baseline and after 6 months of weekly steroids. A subset completed magnetic resonance (MR) evaluation of muscle at study onset and endpoint. At baseline compared to age and sex-matched healthy controls, the aggregate serum protein profile in the WSiMD cohort was dominated by muscle proteins, reflecting leak of muscle proteins into serum. Disease status produced more proteins differentially present in serum compared to steroid-treatment effect. Nonetheless, a response to prednisone was discernable in the WSiMD cohort, even at this low dose. Glucocorticoids downregulated muscle proteins and upregulated certain immune process- and matrix-associated proteins. Muscle MR fat fraction showed trends with functional status. The prednisone-responsive markers could be used in larger trial of prednisone efficacy.

Serum proteinogram of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax) as a new useful approach for detecting loss of haemostasis

Proteinograms, a semiquantitative analytical method that separates proteins into multiple bands, have not been explored in teleosts for diagnostic or prognostic purposes. This study aimed to establish reference values for proteinograms in the serum of gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax), two important farmed fish species in the Mediterranean region. Serum proteins were studied using SDS-PAGE, electropherogram, and HPLC-mass spectrometry. SDS-PAGE analysis revealed four major bands of proteins around 11, 25, 70, and 100 kDa in the serum of gilthead seabream and European sea bass. Electropherogram results showed that a protein with a molecular weight of 76.8 kDa was the most abundant protein in the serum of gilthead seabream, while a peak of 75.5 kDa was the most abundant in European sea bass. HPLC-mass spectrometry detected 87 proteins and 119 proteins in the serum of gilthead seabream and European sea bass, respectively, including α1-globulins, α2-globulins, β-globulins, and γ-globulins. Notably, the albumin sequence was not detected in either of the two species. These results help to characterize the serum protein profile and to establish reference proteinograms for these two fish species. They also provide a basis for the development of novel approaches for the rapid detection of loss of haemostasis due to stress, health disorders or disease in farmed fish.

Metabolomics efficiently discriminates monozygotic twins in peripheral blood.

Monozygotic (MZ) twins cannot be distinguished using conventional forensic STR typing because they present identical STR genotypings. However, MZ twins do not always live in the same environment and often have different dietary and other lifestyle habits. Metabolic profiles are deyermined by individual characteristics and are also influenced by the environment in which they live. Therefore, they are potential markers capable of identifying MZ twins. Moreover, the production of proteins varies from organism to organism and is influenced by both the physiological state of the body and the external environment. Hence, we used metabolomics and proteomics to identify metabolites and proteins in peripheral blood to discriminate MZ twins. We identified 1749 known metabolites and 622 proteins in proteomic analysis. The metabolic profiles of four pairs of MZ twins revealed minor differences in intra-MZ twins and major differences in inter-MZ twins. Each pair of MZ twins exhibited distinct characteristics, and four metabolites-methyl picolinate, acesulfame, paraxanthine, and phenylbenzimidazole sulfonic acid-were observed in all four MZ twin pairs. These four differential exogenous metabolites conincidently show that the different external environments and life styles can be well distinguished by metabolites, considering that twins do not all have the same eating habits and living environments. Moreover, MZ twins showed different protein profiles in serum but not in whole blood. Thus, our results indicate that differential metabolites provide potential biomarkers for the personal identification of MZ twins in forensic medicine.

Serum protein profiling reveals an inflammation signature as a predictor of early breast cancer survival

BackgroundBreast cancers exhibit considerable heterogeneity in their biology, immunology, and prognosis. Currently, no validated, serum protein-based tools are available to evaluate the prognosis of patients with early breast cancer.MethodsThe study population consisted of 521 early-stage breast cancer patients with a median follow-up of 8.9 years. Additionally, 61 patients with breast fibroadenoma or atypical ductal hyperplasia were included as controls. We used a proximity extension assay to measure the preoperative serum levels of 92 proteins associated with inflammatory and immune response processes. The invasive cancers were randomly split into discovery (n = 413) and validation (n = 108) cohorts for the statistical analyses.ResultsUsing LASSO regression, we identified a nine-protein signature (CCL8, CCL23, CCL28, CSCL10, S100A12, IL10, IL10RB, STAMPB2, and TNFβ) that predicted various survival endpoints more accurately than traditional prognostic factors. In the time-dependent analyses, the prognostic power of the model remained rather stable over time. We also developed and validated a 17-protein model with the potential to differentiate benign breast lesions from malignant lesions (Wilcoxon p < 2.2*10− 16; AUC 0.94).ConclusionsInflammation and immunity-related serum proteins have the potential to rise above the classical prognostic factors of early-stage breast cancer. They may also help to distinguish benign from malignant breast lesions.

Inflammatory and subtype-dependent serum protein signatures predict survival beyond the ctDNA in aggressive B cell lymphomas

Biological heterogeneity of large B cell lymphomas (LBCLs) is poorly captured by current prognostic tools, hampering optimal treatment decisions. We dissected the levels of 1,463 serum proteins in a uniformly treated trial cohort of 109 patients with high-risk primary LBCL (ClinicalTrials.gov: NCT01325194) and correlated the profiles with molecular data from tumor tissue and circulating tumor DNA (ctDNA) together with clinical data. We discovered clinically and biologically relevant associations beyond established clinical estimates and ctDNA. We identified an inflamed serum protein profile, which reflected host response to lymphoma, associated with inflamed and exhausted tumor microenvironment features and high ctDNA burden, and translated to poor outcome. We composed an inflammation score based on the identified inflammatory proteins and used the score to predict survival in an independent LBCL trial cohort (ClinicalTrials.gov: NCT03293173). Furthermore, joint analyses with ctDNA uncovered multiple serum proteins that correlate with tumor burden. We found that SERPINA9, TACI, and TARC complement minimally invasive subtype profiling and that TACI and TARC can be used to evaluate treatment response in a subtype-dependent manner in the liquid biopsy. Altogether, we discovered distinct serum protein landscapes that dissect the heterogeneity of LBCLs and provide agile, minimally invasive tools for precision oncology. This research was funded by grants from the Research Council of Finland, Finnish Cancer Organizations, Sigrid Juselius Foundation, University of Helsinki, iCAN Digital Precision Cancer Medicine Flagship, Orion Research Foundation sr, and Helsinki University Hospital.

Concentration of HSPA1A and transthyretin proteins in the blood serum of patients with bipolar disorder

IntroductionInsufficient knowledge about the pathophysiological processes in bipolar disorder (BD) leads to difficulties in differentiating this disorder from other affective disorders. Quantitative analysis of serum protein profiles in BD expands our understanding of the pathophysiology of the disease and may aid in subsequent diagnosis. As a result of a previously conducted comparative mass spectrometric study of serum proteins in patients with depression, bipolar disorder and healthy donors, increased expression of Heat Shock 70kDa Protein1A (HSPA1A) and transthyretin was identified.ObjectivesDetermination of HSPA1A and transthyretin concentrations in the blood serum of patients with mental disorders.MethodsBlood serum of 28 patients with bipolar disorder aged 49 years [33;52], 30 patients with recurrent depressive disorder aged 40 years [31; 51] and 130 patients with schizophrenia aged 38 years [31;49], as well as 20 mentally and somatically healthy individuals aged 35 years [31;40] was studied. The amount of Heat shock protein 1A (HSPA1A) and Transthyretin (thyroxine and retinol transport protein) was determined using a Enzyme-linked Immunosorbent Assay Kit from Homo sapiens (Cloud-Clone Corp). Statistical data processing was carried out in the Statistica 12.0 program.ResultsA statistically significant (p = 0.016) increase in the level of HSPA1A was found in patients with BD (0.84 [0.59; 1.09] ng/ml), compared with healthy individuals (0.61 [0.51; 0.77] ng/ml). HSPA1A plays a pivotal role in the protein quality control system, ensuring the correct folding of proteins. It is known that this protein is involved in the embryonic development of the central nervous system, as well as in neuroprotection by preventing the death of neurons due to its anti-apoptotic properties. A statistically significant (p = 0.047) increase in the level of transthyretin was found in patients with BD 21.8 рg/ml, compared with healthy individuals 19.4 pg/ml. Transthyretin plays an important role in ensuring the normal state of the central nervous system and is involved in cognitive processes.ConclusionsThus, the HSPA1A and transthyretin are probably involved in the pathogenesis of BD and can be proposed as be proposed as an additional paraclinical criterion for differential diagnosis.Support by RSF №23-75-00023.Disclosure of InterestNone Declared

Constitutive Innate Immunity and Systemic Responses to Infection of the American Alligator (Alligator mississippiensis).

Uninfected alligators (Alligator mississippiensis) exhibited high constitutive levels of hepatic gene expression related to immune function, whereas the highest-expressed hepatic genes of uninfected mice were related to metabolism. Intraperitoneal challenge of mice with bacterial lipopolysaccharide results in dramatic inflammatory effects including peritoneal ascites, febrile response, dramatic alterations in electrophoretic serum profile, and mortality. In contrast, coelomic injection of alligators with 200× the murine LD50 of intraperitoneal bacterial lipopolysaccharide resulted in no changes in serum protein profiles, behavioral effects, mortality, and no coelomic ascites. However, injection of juvenile alligators with live bacteria resulted in a titer-dependent decrease in metabolic rate, as measured by oxygen consumption. These results are the opposite of those observed for mammalian and avian species. The decreased oxygen consumption was not accompanied by changes in heart or respiration rate, indicating that this phenomenon was not due to bradycardia or bradypnea. Interestingly, challenge of alligators with bacteria resulted in the complete expulsion of digestive tract contents within four hours. We interpret these activities as temporary minimization of other biological systemic activities to redirect and devote energy to immune function. The reallocation of resources within an organism to fight infection without increases in metabolic rate has not been described in other animals.

Novel Targets and Potential Mechanisms of Mizuhopecten yessoensis-Derived Tripeptide NCW as Antihypertensive Peptides.

Mizuhopecten yessoensis-derived tripeptide Asn-Cys-Trp (NCW) exhibits a potent antihypertensive effect in vivo. However, a lack of knowledge of the antihypertensive mechanism of tripeptide NCW limits its application for functional foods industrialization. The purpose of this study is to elucidate the corresponding targets and mechanisms of tripeptide NCW in hypertension regulation. Administration of tripeptide NCW for 3 weeks, the blood pressure of spontaneously hypertensive rats (SHRs) is significantly decreased. After sacrifice, the serum sample is analyzed using tandem mass tag (TMT)-based liquid chromatography with tandem mass spectrometry to identify differentially expressed proteins. The proteomic analysis indicates that tripeptide NCW administration alters serum protein profiles in SHR rats, significantly upregulating 106 proteins and downregulating 30 proteins. These proteins enhance the glycolysis, glucose, and TCA cycle, improve amino metabolism, trigger the cAMP/PKA, cGMP/PKG, PI3K/AKT, and AMPK signal pathways, and inhibit Ras-regulated JNK activation, TGF-β/MAPK, and TGF-β/ RhoA/ROCK pathways. Tripeptide NCW supplementation is demonstrated to regulate signal pathways involved in the control of blood pressure and regulate the energy and amino acids metabolic processes in serum, providing important insights into the protective effects of tripeptide NCW on hypertension.

A275 THE POTENTIAL MECHANISTIC ROLES OF SPHINGOLIPIDS IN HEALTHY FIRST-DEGREE RELATIVES OF PATIENTS WITH CROHN'S DISEASE

Abstract Background Crohn's Disease(CD) features a complex etiology intertwining genetic, environmental, and immunological dimensions. Sphingolipids (SPs) are pivotal lipid molecules within cell membranes and various biological processes, including cell growth, apoptosis, and inflammatory responses. While our prior research identified SPs as significant risk factors for CD onset, their pre-clinical influence on CD risk biomarkers and potential role in pathogenesis remains unclear Aims To identify the relationship between SPs and established CD risk factors Methods We used samples from healthy first-degree relatives(FDRs), followed in a nested case-control cohort from the Crohn's Colitis Canada- Genes, Environment, Microbial(GEM) project, matching those who developed CD(n=77) with control FDRs(n=303) based on age, sex, follow-up time, and geographic location. 59 SPs were selected from serum metabolites measured via an untargeted metabolomics platform. We used partial Spearman correlation to identify relationships between SPs and CD risk factors: i)intestinal permeability via the urinary fractional excretion ratio of lactulose to mannitol(LMR); ii)gut subclinical inflammation using fecal calprotectin(FCP); iii)systemic inflammation with C-reactive protein(CRP); iv)microbiome composition through fecal 16S rRNA sequencing and v)serum protein profile using the Olink® Proximity Extension Assay platform. A two-sided qampersand:003C0.05 was considered significant Results We identified 38 positive correlations between CRP and SPs across various sub-pathways, including Ceramides, Sphingomyelins and Hexosylceramides(0.117≤rho≤0.342, 1.37×10−09≤q≤0.042). One SP Ceramide(d18:1/16:0) correlated positively with FCP(rho=0.201, q=0.012). Moreover, two SPs, N-palmitoyl-sphingosine (d18:1/16:0) and glycosyl-N-(2-hydroxynervonoyl)-sphingosine (d18:1/24:1(2OH)), correlationed with Peptoclostridium genus (rho=0.465 and -0.245, q=1.47×10−16 and 0.028 respectively). All SPs correlated with one or more proteins, most positively between Sphingosine-1-phosphate and non-receptor tyrosine kinase(rho=0.637, q=1.98 ×10−36) and most negatively between sphingadienine and Chymotrypsin-C protein(rho=-0.334, q=4.11×10−8). No significant correlations emerged between SPs and LMR Conclusions We identified correlations between SPs and CD risk factors. The correlation with CRP suggests SPs might contribute to systemic inflammatory pathways related to CD. Moreover, correlations with the bacterial taxa highlight SPs' potential role in regulating microbial composition. Extensive correlations with proteins emphasize the pivotal impact of SPs on their function. This study may offer new insights into CD prevention Funding Agencies CCC, CIHR

Serum protein profiling reveals distinct patient clusters in giant cell arteritis.

We investigated the potential of serum proteins for distinguishing clinical and molecular subtypes in patients with GCA. Proximity extension assays were used to analyse 1463 proteins in serum samples from patients with new-onset GCA (n = 16) and patients who have achieved remission (n = 13). Unsupervised and supervised cluster analyses were performed. Unsupervised cluster analysis identified three distinct clusters based on the protein signature. Compared with cluster 2, patients of cluster 1 had fewer PMR symptoms, increased levels of macrophage migration inhibitory factor (MIF) and pronounced NF-κB, STAT5 and IL-1 signalling. The changes in serum proteins upon remission differed between cluster 1 and 2.Patients with cranial GCA were characterized by altered endothelial and Th17 signalling, whereas patients not responding to treatment within the GUSTO-trial showed increased Th1 and diminished B cell signalling. Patients with anterior ischaemic optic neuropathy displayed higher levels of CHI3L1 (YKL40) and MMP12, and reduced levels of TIMP3. Protein profiling identified patient clusters in GCA with distinct proteomic features and therefore likely different pathophysiology. These unique proteomic footprints might lead to more targeted treatments in future.

P305 The serum protein profile across the IBD spectrum: Results from the COLLIBRI consortium

Abstract Background Inflammatory bowel disease (IBD) is a heterogeneous disorder. Both subtypes, i.e., Crohn’s disease (CD) and ulcerative colitis (UC), differ in disease behaviour and inflamed gastrointestinal segments. Despite this, randomized controlled trials stratify patients based on CD and UC. Molecular characterization could uncover subtype-specific differences that could guide treatment and thereby overcome current therapeutic limitations. Therefore, we aimed to examine differences in serum inflammatory protein profiles across the IBD spectrum. Methods This was a cross-sectional multicentre study of adult patients (≥18 years) with IBD from one Belgian and eight Swedish hospitals in the COLLIBRI consortium. IBD diagnosis and classification was based on international criteria, according to the Montreal classification. Relative serum protein levels were assessed using proximity extension assay technology (Olink Proteomics, Uppsala, Sweden; inflammation panel). We adopted smoothly clipped absolute deviation penalized logistic regression models to discriminate CD and UC patients. Using fitted CD vs UC logistic models, we estimated probability scores of CD vs UC for each patient based on their serum protein profiles. Scores ranged from 0 to 1, where lower scores indicated a higher molecular resemblance to UC. We evaluated the performance using leave-one-out cross-validation and the area under the curve (AUC). Results Relative levels of 86 serum inflammatory proteins were available from 1,551 patients with IBD (CD, N=883; UC, N=639 and IBD-U, N=29) (Table 1). CD vs UC probability scores based on protein estimates for patients with UC, IBDU and different CD phenotypes (ileal CD, L1; colonic CD, L2; ileocolonic CD L3) are shown in Figure 1A. We observed a spectrum of IBD patients based on their CD vs CD probability scores with most pronounced differences between ileal CD and UC. Probability scores also differed significantly between colonic CD and ileal CD, but not between ileal and ileocolonic CD. The model performance to discriminate CD and UC yielded an AUC of 0.75. Restricting the samples to only one CD phenotype vs UC respectively resulted in the highest AUC for ileal CD (0.81), followed by ileocolonic CD (0.75) and colonic CD (0.65). Key proteins in the CD vs. UC model with higher protein estimates in UC were IL-17A, MMP10, FGF19. Contrary, CSF1, and SLAMF1, were higher in CD (Figure 1B). Conclusion Our results on inflammation related serum proteins advocate for a more nuanced classification of CD into ileal-predominant and colonic-predominant subtypes. Such stratification could advance our understanding of IBD pathophysiology and may provide guidance for future therapeutic approaches.