Hemoglobin Subunits Research Articles

Abstract A032: Performance evaluation of a new protein stabilizing blood collection tube with a novel whole blood separation device for clinical plasma proteomics

Abstract Introduction: We have developed a novel blood separation device (BCD) which separates plasma from cellular components by lateral flow and stabilizes the sample for transport to a testing laboratory. Patient blood is drawn into an anticoagulant blood collection tube (BCT) and then applied to the separation device. There is outstanding interest in the field of clinical proteomics regarding the formulation in BCTs and whether they would also additionally the plasma proteome. This is especially critical where hemoglobin may provide interference to the analyte being measured. We evaluated the performance of a newly available plasma protein stabilizing BCT in combination with the BCD and other currently available K2EDTA BCT (no stabilization). Methods: Whole blood from normal healthy donors was drawn into protein stabilizing BCT and a comparator anticoagulant BCT. At baseline, 24-, 48-, 72- and 120-hour time points, a 250 μL aliquot of whole blood from each tube was spotted on to the BCD to allow separation of the cellular components and plasma. All of the test specimens on the spotted devices were allowed to dry overnight to replicate time in transit. After drying, proteins were subjected to MALDI-TOF MS (mass spectrometry) after extraction with water and co- crystallization with sinapinic acid. Spectra were acquired in triplicate and m/z feature intensities for hemoglobin were assessed in R. Results: Visual inspection of the new protein stabilizing and K2EDTA BCTs showed the steady accumulation of hemoglobin over time in the plasma layer in the latter tubes. After spotting on the BCD and MALDI-TOF analysis, plasma from the protein- stabilizing BCT showed no significant increases in either the hemoglobin α or β subunits over the five (5) day period. This was consistent across all donors (heme α p = 0.7933, heme β p = 0.6425) and at all timepoints assessed. In the K2EDTA BCT, both the α and β hemoglobin subunits increased significantly over time and across all donors (heme α p < 0.0001, heme β p = 0.0232). The hemoglobin α subunit accumulated in the plasma component to a greater degree than did the β subunit (heme α slope = 4.863E-5, heme β slope = 1.398E-5). These data suggest that the formulation in the protein stabilizing BCT may attenuate red blood cell hemolysis to a greater degree as compared to conventional K2EDTA blood collection tubes. Additionally, the mean reproducibility for both hemoglobin subunits was lower when the protein stabilizing BCT was used than when the anticoagulant BCT was used across all donors at all time points (protein stabilizing BCT x ̅ CV = 8.5%, anticoagulant BCT x ̅ CV = 8.9%). Conclusions: The use of the newly available protein stabilizing BCT with the BCD reduces the accumulation of hemoglobin in the plasma component while improving reproducibility when compared to the currently used anticoagulant BCT. Interference by heme was significantly attenuated as measured by a sensitive MALDI-ToF assay. Citation Format: Colin McDowell, Nylev Vargas, Gary A Pestano. Performance evaluation of a new protein stabilizing blood collection tube with a novel whole blood separation device for clinical plasma proteomics [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A032.

Haemoglobin Gene Repertoire in Teleost and Cichlid Fishes Shaped by Gene Duplications and Genome Rearrangements.

Haemoglobin is a key molecule for oxygen transport in vertebrates. It exhibits remarkable gene diversity in teleost fishes, reflecting adaptation to various aquatic environments. In this study, we present the dynamic evolution of haemoglobin subunit genes based on a comparison of high-quality genome assemblies of 24 vertebrate species, including 17 teleosts (of which six are cichlids). Our findings indicate that teleost genomes contain a range of haemoglobin genes, from as few as five in fugu to as many as 43 in salmon, with the latter being the largest repertoire found in vertebrates. We find evidence that the teleost ancestor had at least four Hbα and three or four Hbβ subunit genes, and that the current gene diversity emerged during teleost radiation, driven primarily by (tandem) gene duplications, genome compaction, and rearrangement dynamics. We provide insights into the genomic organisation of haemoglobin clusters in different teleost species. We further show that the evolution of paralogous rhbdf1 genes flanking both teleost clusters (LA and MN) supports the hypothesis for the origin of the LA cluster by rearrangement within teleosts, rather than by the teleost specific whole-genome duplication. We specifically focus on cichlid fishes, where adaptation to low oxygen environment plays role in species diversification. Our analysis of six cichlid genomes, including Pungu maclareni from the Barombi Mbo crater lake, for which we sequenced a representative genome, reveals 18-32 copies of the Hb genes, and elevated rates of non-synonymous substitutions compared to other teleosts. Overall, this work facilitates a deeper understanding of how haemoglobin genes contribute to the adaptive potential of teleosts.

Responsiveness of anti-VEGF treatment for polypoidal choroidal vasculopathy based on aqueous humour proteomics: A preliminary study.

Patients with polypoidal choroidal vasculopathy (PCV) exhibit variability in response to anti-VEGF therapy. This study aimed to analyse the aqueous humour proteomic profiles of PCV patients and provide preliminary insights for the identification of biomarkers associated with anti-VEGF drug responsiveness. PCV patients who were treatment-naïve or untreated for more than 3 months were prospectively recruited from two hospitals in Beijing and Tianjin. Based on the relative changes in central macular thickness (ΔCMT/baseline-CMT) before and after anti-VEGF treatment, the PCV patients were divided into a good response (GR) group (≤-25%) and a poor response (PR) group (>-25%). Aqueous humour proteomics was performed by the Data-independent Acquisition-Mass Spectrometry (DIA-MS) method, and differentially expressed proteins (DEPs) analysis between the different PCV groups and the control group was conducted. Key DEPs were selected for preliminary validation in the aqueous humour using the Luminex method retrospectively. A total of 31 PCV patients (31 eyes) were included, 13 in the GR group and 18 in the PR group. A total of 414 DEPs were identified, including 36 significantly upregulated proteins, such as G protein regulatory factor 10 (RGS10), podocin (PODN) and epidermal growth factor (EGF), and 32 downregulated proteins, including RAB11FIP4 (Rab11 family-interacting protein 4), α-synuclein (SNCA), haemoglobin subunit δ (HBD) and interleukin 6 (IL6). Compared to the cataract control group (10 eyes), 134 proteins were significantly upregulated, and 72 were downregulated. KEGG pathway enrichment analysis revealed that the GR and PR groups differ in terms of cell communication, and cell signal transduction. Protein-protein interaction analysis revealed interactions between EGF and various DEPs. Validation of aqueous humour proteins using the Luminex method revealed that changes in the levels of EGF were associated with the anti-VEGF treatment response in PCV patients. PCV patients with good or poor anti-VEGF responses exhibit distinct aqueous humour proteomic profiles. Aqueous EGF may serve as a biomarker for the 'precise treatment' of PCV.

Nitrosyl hemoglobin formation from nitrite in normal and sickle blood

Sickle cell anemia is caused by a single mutation in the gene encoding the beta subunit of hemoglobin. Due to this mutation, sickle cell hemoglobin (HbS) polymerizes under hypoxic conditions, decreasing red blood cell deformability and leading to multiple pathological effects that cause substantial morbidity and mortality. Several pre-clinical and human studies have demonstrated that the anion nitrite has potential therapeutic benefits for patients with sickle cell disease. Nitrite is reduced to nitric oxide (NO) by deoxygenated hemoglobin contributing to vasodilation, decreasing platelet activation, decreasing cellular adhesion to activated endothelium, and decreasing red cell hemolysis; all of which could ameliorate patient morbidities. Previous work on extracellular hemoglobin has shown that solution phase HbS reduces nitrite to NO faster than normal adult hemoglobin (HbA), while polymerized HbS reduces nitrite slower than HbA. In this work, we compared the rate of nitrite reduction to NO measured by the formation of nitrosyl hemoglobin in sickle and normal red blood cells at varying hemoglobin oxygen saturations. We found the overall rate of nitrite reduction between normal and sickle red blood cells was similar and confirmed this result under partially oxygenated conditions, but normal red blood cells reduced nitrite faster than sickle red blood cells under anoxia where HbS polymerization is maximal. These results are consistent with previous work using extracellular hemoglobin where the rate of reduction by solution phase HbS makes up for the slower reduction by polymer phase HbS under partially oxygenated conditions, but the polymer phase kinetics dominates in the complete absence of oxygen.

Proteome of the 2-h in vivo Formed Acquired Enamel Pellicle of Adolescents with Erosive Tooth Wear, Caries, or Sound

Introduction: Acquired pellicle (AP) acts as a membrane preventing acids from coming into direct contact with the tooth. Possibly, individuals with different dental health status present changes in its composition that could disrupt this function. Thus, the aim of this study was to compare the protein composition of the AP in adolescents with erosive tooth wear (ETW), caries, or sound. Methods: Calibrated examiners in BEWE index and ICDAS-merged Epi criteria assessed ETW and caries in a sample of 454 systemically healthy adolescents aged 12–15 years old. Thirty subjects from that sample were selected for this study: ETW group (n = 10; total BEWE ≥9 and absence of dentinal caries lesions); caries group (n = 10; total BEWE <9 and with at least one dentinal caries lesion), and sound group (n = 10; total BEWE <9 and absence of dentinal caries lesions). Two-hour-formation AP samples were taken from buccal, occlusal/incisal, palatal/lingual tooth surfaces. Protein composition was analysed by liquid chromatography-tandem mass spectrometry. Using mean reporter ion values, relative abundances of proteins were compared among the three groups to calculate for fold changes. Twofold protein increases or decreases were reported (t test, p < 0.05). Gene Ontology (GO) of included proteins was assigned. Results: Mean age of participants was 13.1 ± 1.14 years and 56.6% were females. The prevalence of ETW was of 66.6% and of dentinal caries of 33.3%. The GO analyses showed that the majority of detected proteins were stress response related. The ETW group disclosed upregulated relative abundance of antileukoprotease (2.85-fold in ETW vs. sound and 2.34-fold in ETW group vs. caries group); histatin (2.42-fold in ETW group vs. sound group and 2.20-fold in ETW group vs. caries group), and prolactin-induced protein (2.30-fold in ETW group vs. sound group and 2.06-fold in ETW group vs. caries group) (p < 0.05). Hemoglobin subunits alpha (HBA) and beta (HBB) showed decreased relative abundances in the ETW and caries groups when compared to the sound group (HBA: 0.42-fold in ETW group and 0.40-fold in caries group; HBB: 0.45-fold in ETW group and 0.38-fold in caries group; p < 0.05). Conclusion: AP from individuals with ETW showed differences when compared to other dental conditions, with relative abundance increasing of some stress response-associated proteins in ETW and a decrease in proteins related to salivary protection against acid challenges.

Refrigerated Storage-Induced Quality Deterioration of Mandarin Fish (Siniperca chuatsi): Analyzing the Role of Endogenous Enzymes through TMT-Based Quantitative Proteomics

Tandem Mass Tag (TMT)-based proteomics was employed to elucidate the pivotal role of endogenous enzymes in the quality deterioration of Mandarin fish (Siniperca chuatsi) during refrigerated storage. Proclean 300 was used to inhibit the growth of psychrophilic microorganisms, emphasizing the contribution of endogenous enzymes. Quality characteristics, including pH, water-holding capacity, color, texture, and myofibrillar fragmentation index (MFI), were compared between the Proclean 300-treated group (P-group) and the control group (C-group). Correlation analysis underscored the collaborative role of calpain and cathepsin B in postmortem degradation. Pearson correlation analysis showed that texture characteristics were significantly negatively correlated with MFI and significantly positively correlated with whiteness and L* in the P-group. Differentially expressed proteins (DEPs) analysis identified 66 DEPs, with 40 exhibiting low abundance, including cytoskeleton proteins and hemoglobin subunits, and 26 showing high abundance, primarily metabolic enzymes. Bioinformatics analysis revealed significant enrichment of DEPs within the glycolysis/gluconeogenesis pathway. Furthermore, protein-protein interaction analysis highlighted key proteins linked to the quality deterioration of Mandarin fish, including beta-enolase, phosphoglycerate kinase 1, and triosephosphate isomerase B. These findings offer valuable insights into the mechanisms behind the quality deterioration of refrigerated Mandarin fish and the intricate relationship with endogenous enzymes.

Taming hemoglobin chemistry—a new hemoglobin-based oxygen carrier engineered with both decreased rates of nitric oxide scavenging and lipid oxidation

The clinical utility of hemoglobin-based oxygen carriers (HBOC) is limited by adverse heme oxidative chemistry. A variety of tyrosine residues were inserted on the surface of the γ subunit of recombinant fetal hemoglobin to create novel electron transport pathways. This enhanced the ability of the physiological antioxidant ascorbate to reduce ferryl heme and decrease lipid peroxidation. The γL96Y mutation presented the best profile of oxidative protection unaccompanied by loss of protein stability and function. N-terminal deletions were constructed to facilitate the production of recombinant hemoglobin by fermentation and phenylalanine insertions in the heme pocket to decrease the rate of NO dioxygenation. The resultant mutant (αV1del. αL29F, γG1del. γV67F, γL96Y) significantly decreased NO scavenging and lipid peroxidation in vitro. Unlike native hemoglobin or a recombinant control (αV1del, γG1del), this mutation showed no increase in blood pressure immediately following infusion in a rat model of reperfusion injury, suggesting that it was also able to prevent NO scavenging in vivo. Infusion of the mutant also resulted in no meaningful adverse physiological effects apart from diuresis, and no increase in oxidative stress, as measured by urinary isoprostane levels. Following PEGylation via the Euro-PEG-Hb method to increase vascular retention, this novel protein construct was compared with saline in a severe rat reperfusion injury model (45% blood volume removal for 90 minutes followed by reinfusion to twice the volume of shed blood). Blood pressure and survival were followed for 4 h post-reperfusion. While there was no difference in blood pressure, the PEGylated Hb mutant significantly increased survival.

Hemoglobin alpha is a redox-sensitive mitochondrial-related protein in T-lymphocytes.

Hemoglobin subunits, which form the well-characterized, tetrameric, oxygen-carrying protein, have recently been described to be expressed in various non-canonical cell types. However, the exact function of hemoglobin subunits within these cells remains to be fully elucidated. Herein, we report for the first time, the expression of hemoglobin alpha-a1 (Hba-a1) in T-lymphocytes and describe its role as a mitochondrial-associated antioxidant. Within naïve T-lymphocytes, Hba-a1 mRNA and HBA protein are present and highly induced by redox perturbations, particularly those arising from the mitochondria. Additionally, preliminary data using a T-lymphocyte specific Hba-a1 knock-out mouse model indicated that the loss of Hba-a1 led to an exacerbated production of mitochondrial reactive oxygen species and inflammatory cytokines after a stress challenge, further supporting the role of HBA acting to buffer the mitochondrial redox environment. Interestingly, we observed Hba-a1 expression to be significantly upregulated or downregulated depending on T-lymphocyte polarization and metabolic state, which appeared to be controlled by both transcriptional regulation and chromatin remodeling. Altogether, these data suggest Hba-a1 may function as a crucial mitochondrial-associated antioxidant and appears to possess critical and complex functions related to T-lymphocyte activation and differentiation.

Sickle Cell Hemoglobin "Drugged" with Cyclic Peptides Is Aggregation Incompetent.

Sickle cell disease (SCD) is a monogenic blood disorder associated with a mutation in the hemoglobin subunit β gene encoding for the β-globin of normal adult hemoglobin (HbA). This mutation transcribes into a Glu-β6 → Val-β6 substitution in the β-globins, inducing the polymerization of this hemoglobin form (HbS) when in the T-state. Despite advances in stem cell and gene therapy, and the recent approval of a new antisickling drug, therapeutic limitations persist. Herein, we demonstrate through molecular dynamics and umbrella sampling, that (unrestrained) blockage of the hydrophobic pocket involved in the lateral contact of the HbS fibers by 5-mer cyclic peptides, recently proposed as SCD aggregation inhibitors (Neto, V.; J. Med. Chem. 2023, 66, 16062-16074), is enough to turn the dimerization of HbS thermodynamically unfavorable. Among these potential drugs, some exhibit an estimated pocket abandonment probability of around 15-20% within the simulations' time frame, and an impressive specificity toward the mutated Val-β6. Additionally, we show that the dimerization can be thermodynamically unfavored by blocking a nearby region while the pocket remains vacant. These results are compared with curcumin, an antisickling molecule and a pan-assay interference compound, with a good binding affinity for different proteins and protein domains. Our results confirm the potential of some of these cyclic peptides as antisickling drug candidates to reduce the concentration of aggregation-competent HbS.

In vivo silencing of intestinal DMT1 mitigates iron loading in β-thalassemia intermedia (Hbbth3/+) mice

Abstractβ-thalassemia is an iron-loading anemia caused by homozygous mutation of the hemoglobin subunit β (HBB) gene. In β-thalassemia intermedia (βTI), a non–transfusion-dependent form of the disease, iron overload is caused by excessive absorption of dietary iron due to inappropriately low production of the iron-regulatory hormone hepcidin. Low hepcidin stabilizes the iron exporter ferroportin (FPN) on the basolateral membrane of enterocytes. High FPN activity may deplete intracellular iron and enhance expression of the predominant iron importer divalent metal-ion transporter 1 (DMT1). In mice, DMT1 mediates normal iron absorption under physiological conditions and excessive iron absorption in pathological iron overload (eg, hereditary hemochromatosis). Here, we hypothesized that DMT1 drives elevated iron absorption in βTI. Accordingly, we crossed Hbbth3/+ mice, a preclinical model of βTI, with intestine-specific DMT1-knockout mice. Ablation of intestinal DMT1 in Hbbth3/+ mice caused a pathophysiological shift from iron overload to an iron-deficiency phenotype with exacerbated anemia. DMT1 is thus required for iron absorption and iron loading in Hbbth3/+ mice. Based upon these outcomes, we further logically postulated that in vivo knockdown of intestinal DMT1 would mitigate iron loading in Hbbth3/+ mice. Ginger-derived, lipid nanoparticles carrying DMT1-specific (or control) small interfering RNAs (siRNAs) were administered by oral, intragastric gavage to 4-week-old Hbbth3/+ mice daily for 16 days. siRNA treatment reduced DMT1 expression by >80% and blunted iron loading, as indicated by significant reductions in liver iron and serum ferritin (which reflect body iron stores). These notable experimental outcomes establish intestinal DMT1 as a plausible therapeutic target to mitigate iron overload in βTI.

Hemoglobinopathy for Malaria Protection: A Comprehensive Review

Hemoglobinopathies, including sickle cell disease (SCD) and thalassemia, are inherited disorders that affect hemoglobin structure and function, leading to significant health implications. However, these genetic conditions also confer a degree of protection against malaria, particularly Plasmodium falciparum, the most virulent malaria parasite. This comprehensive review examines the relationship between hemoglobinopathies and malaria protection, exploring how genetic mutations in hemoglobin subunits influence susceptibility to malaria. Sickle cell trait (HbAS) provides notable protection against severe malaria, with mechanisms including reduced parasite growth, enhanced immune clearance, and microvascular obstruction. Although homozygous sickle cell disease (HbSS) does not confer protection and leads to severe complications, the high prevalence of HbS in malaria-endemic regions underscores an evolutionary balance. Thalassemia, both alpha and beta types, also offers partial malaria protection by altering the red blood cell environment, though the precise mechanisms remain less understood. Additionally, other hemoglobin variants, such as hemoglobin C (HbC) and hemoglobin E (HbE), demonstrate varying degrees of malaria resistance. The review highlights the evolutionary and epidemiological evidence supporting the protective effects of these genetic traits, emphasizing their role in malaria-endemic regions. Public health implications include the need for genetic counseling and targeted malaria control strategies. Future research directions include elucidating mechanistic pathways, exploring regional variations, and assessing the impact on malaria vaccine efficacy. By integrating insights from hemoglobinopathy research into public health interventions, more effective malaria control strategies can be developed, ultimately improving health outcomes for affected populations. Keywords: Hemoglobinopathies, Sickle Cell Disease, Thalassemia, Malaria Protection, Plasmodium falciparum.

P093 PLASMA PROTEINS PROFILE AND THERAPEUTIC RESPONSIVENESS IN PATIENTS WITH PREECLAMPSIA

Preeclampsia (PE) is a hypertensive syndrome of pregnancy, characterized by target organ damage, related to a high incidence of cardiovascular sequelae. PE requires antihypertensive drug therapy, however, about 40% of patients do not respond to this treatment, leading to worse clinical outcomes. Through the proteomic strategy, we 1) compared the profile of circulating proteins expressed in 10 responsive (R-PE) and 10 non-responsive to antihypertensive therapy (NR-PE), besides 10 healthy pregnant (HP); 2) investigated which proteins are differentially expressed between the groups and 3) found out which signaling pathways are altered between them. The study followed the Declaration of Helsinki and was approved by the Research Ethics Committee of the Ribeirao Preto Medical School, University of Sao Paulo (FMRP-USP, protocol code CAAE-37738620.0.0000.5440). We performed plasma protein quantification using mass spectrometry, the obtained data underwent bioinformatics analyses based on Uniprot, PatternLab for Proteomics, String and MetaboAnalyst softwares. Considering a fold change of 1.5, three proteins showed as significantly differentially expressed between HP and R-PE, one downregulated (transtyretin) and two upregulated (apolipoprotein C1 and hemoglobin subunit beta). Between HP and NR-PE, there were six, two downregulated (clusterin and plasmin heavy chain A) and four upregulated (apolipoprotein A-IV; heparin cofactor II; complement C4B and haptoglobin related protein). Between R-PE and NR-PE there were four, one downregulated (fibronectin) and three upregulated (pregnancy-specific beta-1-glycoprotein 1 (PSG1); complement C4B (C4B) and complement C4A (C4A). Regarding PE, C4A and C4B intensity peaks were correlated with blood pressure and creatinine levels. Both, together with PSG1, showed significant correlations with the newborn's weight and gestational week (all p&lt; 0.05). These findings help to understand the pathophysiological mechanisms between the two subgroups of the disease, since the under regulated circulating proteins act in the blood pressure modulation and the upregulated may occur as compensatory mechanisms due to an inflammatory scenario. These data give insights to explain the complexity and clinical consequences of this disorder.

Rare host variants in ciliary expressed genes contribute to COVID-19 severity in Bulgarian patients

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), a pneumonia with extremely heterogeneous clinical presentation, ranging from asymptomatic to severely ill patients. Previous studies have reported links between the presence of host genetic variants and the outcome of the COVID-19 infection. In our study, we used whole exome sequencing in a cohort of 444 SARS-CoV-2 patients, admitted to hospital in the period October-2020–April-2022, to search for associations between rare pathogenic/potentially pathogenic variants and COVID-19 progression. We used gene prioritization-based analysis in genes that have been reported by host genetic studies. Although we did not identify correlation between the presence of rare pathogenic variants and COVID-19 outcome, in critically ill patients we detected known mutations in a number of genes associated with severe disease related to cardiovascular disease, primary ciliary dyskinesia, cystic fibrosis, DNA damage repair response, coagulation, primary immune disorder, hemoglobin subunit β, and others. Additionally, we report 93 novel pathogenic variants found in severely infected patients who required intubation or died. A network analysis showed main component, consisting of 13 highly interconnected genes related to epithelial cilium. In conclusion, we have detected rare pathogenic host variants that may have influenced the COVID-19 outcome in Bulgarian patients.

Distinct protein patterns related to postnatal development in small for gestational age preterm infants.

Preterm infants, especially those born small for gestational age (SGA), are at risk of short-term and long-term health complications. Characterization of changes in circulating proteins postnatally in preterm infants may provide valuable fundamental insights into this population. Here, we investigated postnatal developmental patterns in preterm infants and explored protein signatures that deviate between SGA infants and appropriate for gestational age (AGA) infants using a mass spectrometry (MS)-based proteomics workflow. Longitudinal serum samples obtained at postnatal days 0, 3, 7, 14, and 28 from 67 preterm infants were analyzed using unbiased MS-based proteomics. 314 out of 833 quantified serum proteins change postnatally, including previously described age-related changes in immunoglobulins, hemoglobin subunits, and new developmental patterns, e.g. apolipoproteins (APOA4) and terminal complement cascade (C9) proteins. Limited differences between SGA and AGA infants were found at birth while longitudinal monitoring revealed 69 deviating proteins, including insulin-sensitizing hormone adiponectin, platelet proteins, and 24 proteins with an annotated function in the immune response. This study shows the potential of MS-based serum profiling in defining circulating protein trajectories in the preterm infant population and its ability to identify longitudinal alterations in protein levels associated with SGA. Postnatal changes of circulating proteins in preterm infants have not fully been elucidated but may contribute to development of health complications. Mass spectrometry-based analysis is an attractive approach to study circulating proteins in preterm infants with limited material. Longitudinal plasma profiling reveals postnatal developmental-related patterns in preterm infants (314/833 proteins) including previously described changes, but also previously unreported proteins. Longitudinal monitoring revealed an immune response signature between SGA and AGA infants. This study highlights the importance of taking postnatal changes into account for translational studies in preterm infants.

Different Proteomic Profiles Regarding Antihypertensive Therapy in Preeclampsia Pregnant.

Preeclampsia (PE) is a hypertensive pregnancy syndrome associated with target organ damage and increased cardiovascular risks, necessitating antihypertensive therapy. However, approximately 40% of patients are nonresponsive to treatment, which results in worse clinical outcomes. This study aimed to compare circulating proteomic profiles and identify differentially expressed proteins among 10 responsive (R-PE), 10 nonresponsive (NR-PE) patients, and 10 healthy pregnant controls (HP). We also explored correlations between these proteins and clinical data. Plasma protein relative quantification was performed using mass spectrometry, followed by bioinformatics analyses with the UniProt database, PatternLab for Proteomics 4.0, and MetaboAnalyst software (version 6.0). Considering a fold change of 1.5, four proteins were differentially expressed between NR-PE and R-PE: one upregulated (fibronectin) and three downregulated (pregnancy-specific beta-1-glycoprotein 1, complement C4B, and complement C4A). Between NR-PE and HP, six proteins were differentially expressed: two upregulated (clusterin and plasmin heavy chain A) and four downregulated (apolipoprotein L1, heparin cofactor II, complement C4B, and haptoglobin-related protein). Three proteins were differentially expressed between R-PE and HP: one downregulated (transthyretin) and two upregulated (apolipoprotein C1 and hemoglobin subunit beta). These findings suggest a complex interplay of these proteins involved in inflammatory, immune, and metabolic processes with antihypertensive therapy responsiveness and PE pathophysiology.

Longitudinal transcriptomic analysis reveals persistent enrichment of iron homeostasis and erythrocyte function pathways in severe COVID-19 ARDS.

The acute respiratory distress syndrome (ARDS) is a common complication of severe COVID-19 and contributes to patient morbidity and mortality. ARDS is a heterogeneous syndrome caused by various insults, and results in acute hypoxemic respiratory failure. Patients with ARDS from COVID-19 may represent a subgroup of ARDS patients with distinct molecular profiles that drive disease outcomes. Here, we hypothesized that longitudinal transcriptomic analysis may identify distinct dynamic pathobiological pathways during COVID-19 ARDS. We identified a patient cohort from an existing ICU biorepository and established three groups for comparison: 1) patients with COVID-19 ARDS that survived hospitalization (COVID survivors, n = 4), 2) patients with COVID-19 ARDS that did not survive hospitalization (COVID non-survivors, n = 5), and 3) patients with ARDS from other causes as a control group (ARDS controls, n = 4). RNA was isolated from peripheral blood mononuclear cells (PBMCs) at 4 time points (Days 1, 3, 7, and 10 following ICU admission) and analyzed by bulk RNA sequencing. We first compared transcriptomes between groups at individual timepoints and observed significant heterogeneity in differentially expressed genes (DEGs). Next, we utilized the likelihood ratio test to identify genes that exhibit different patterns of change over time between the 3 groups and identified 341 DEGs across time, including hemoglobin subunit alpha 2 (HBA1, HBA2), hemoglobin subunit beta (HBB), von Willebrand factor C and EGF domains (VWCE), and carbonic anhydrase 1 (CA1), which all demonstrated persistent upregulation in the COVID non-survivors compared to COVID survivors. Of the 341 DEGs, 314 demonstrated a similar pattern of persistent increased gene expression in COVID non-survivors compared to survivors, associated with canonical pathways of iron homeostasis signaling, erythrocyte interaction with oxygen and carbon dioxide, erythropoietin signaling, heme biosynthesis, metabolism of porphyrins, and iron uptake and transport. These findings describe significant differences in gene regulation during patient ICU course between survivors and non-survivors of COVID-19 ARDS. We identified multiple pathways that suggest heme and red blood cell metabolism contribute to disease outcomes. This approach is generalizable to larger cohorts and supports an approach of longitudinal sampling in ARDS molecular profiling studies, which may identify novel targetable pathways of injury and resolution.

Abstract Mo103: Aberrant Trans- and De- Nitrosylation Underpins Nitrosative Stress in Cardiometabolic HFpEF

Background: Heart failure with preserved ejection fraction (HFpEF) is among the leading causes of cardiovascular mortality and morbidity. Recent reports suggest excessive myocardial protein S-nitrosylation (-SNO), a hallmark of nitrosative stress, contributes to HFpEF pathophysiology. However, the role of transnitrosylases, enzymes that induce protein-SNO, or denitrosylases, enzymes that eliminate protein-SNO, have not been investigated in the context of HFpEF. Research Questions and Goals: We sought to investigate the regulation of protein nitrosylation dynamics in a rat model of cardiometabolic HFpEF. Methods: Echocardiographic assessment, invasive hemodynamic measurements, and exercise testing were conducted in WKY or ZSF1 obese (Ob) rats to evaluate HFpEF severity. Nitric oxide (NO) bioavailability and protein-SNO levels were determined in the heart tissue. Endothelial-dependent vascular reactivity was assayed to further evaluate NO signaling. In parallel, single-cell (sc) RNA sequencing was performed to determine the transcriptional changes in trans- and denitrosylases, as well as NO synthases. Results: We observed progressive deterioration in LV diastolic function (significantly elevated E/e’ and LV end-diastolic pressure) and exercise performance in ZSF1 Ob when compared to WKY controls. Notably, ZSF1 Ob rats exhibited an age-dependent elevation in protein-SNO levels, despite significant reduction in NO bioavailability and signaling. Targeted sc transcriptomic analysis revealed significantly elevated expression of transnitrosylases such as hemoglobin subunit α and β in cardiomyocytes, endothelial cells, and cardiac fibroblasts from ZSF1 Ob hearts. In contrast, significantly reduced expression of denitrosylases such as thioredoxin 2 was found in the ZSF1 Ob cardiomyocytes. No change was observed in expression of NO synthases (nNOS, iNOS, eNOS). Conclusion: Herein, we demonstrate a profound disconnect between insufficient NO bioavailability and nitrosative stress in ZSF1 Ob rat model of HFpEF. Our data suggests the pathological accumulation of nitroso - proteins, may be attributed in part to the derangement of transnitrosylases and denitrosylases expression. Restoration of physiological protein nitrosylation dynamics may represent a novel therapeutic approach for HFpEF, and warrants further investigation.

Prospecting Specific Protein Patterns for High Body Mass Index (BMI), Metabolic Syndrome and Type 2 Diabetes in Saliva and Blood Plasma From a Brazilian Population.

Obesity and its associated metabolic disorders, such as T2DM and MeS, are a growing public health problem worldwide. Our goal was the identification of protein patterns that are uniquely characteristic of higher BMI, MeS, and T2DM in a Brazilian population. Saliva and plasma proteomes, clinical parameters were analyzed in a population from the state of Rio de Janeiro, Brazil, a mixed-race population. Volunteers were sorted by their BMI into normal (n = 29), overweight (n = 25), and obese (n = 15) and were compared with individuals with MeS (n = 23) and T2DM (n = 11). The Random Forest (RF) predictive model revealed that three clinical variables, BMI, HOMA-IR, and fasting blood glucose, are most important for predicting MeS and T2DM. A total of six plasmatic proteins (ABCD4, LDB1, PDZ, podoplanin, lipirin-alpha-3, and WRS) and six salivary proteins (hemoglobin subunit beta, POTEE, T cell receptor alpha variable 9-2, lactotransferrin, cystatin-S, carbonic anhydrase 6), are enhanced in T2DM and in MeS. Our data revealed similar alterations in protein composition across individuals with abnormal weight gain, T2DM, and MeS. This finding confirms the close link between these conditions at the molecular level in the studied population, potentially enhancing our understanding of these diseases and paving the way for the development of novel diagnostic tools.

Mutation Analysis of Exon 1 in the Hemoglobin Subunit Beta (HBB) Gene in Beta-Thalassemia.

Introduction Thalassemia is a widely prevalent monogenic hematological disorder found worldwide. It exists in two forms: alpha- and beta-thalassemia. Alterations in the hemoglobin subunit beta (HBB) gene cause beta-thalassemia, with missense and point mutations affecting beta-globin synthesis. Consequently, genetic screening for beta-thalassemia is essential for genetic counseling, carrier screening, and prenatal diagnosis. Aim and objective This study aims to examine and identify mutations in the exon 1 region of the HBB gene in beta-thalassemia patients from the Vijayapura region. Methods This study involved 47 clinically diagnosed children with beta-thalassemia from a hospital in Vijayapura, India. Detailed clinical histories of all patients were recorded. Genomic DNA was extracted from the blood samples of these patients and subjected to polymerase chain reaction (PCR) using exon-specific primers for the HBB gene. The PCR products were then sequenced using the capillary-based Sanger sequencing method to identify mutations in the HBB gene. Results A total of 47 clinically diagnosed beta-thalassemia patients were included in the study, comprising 30 males and 17 females, aged between one and 20 years. Sequencing analysis of exon 1 in the beta-globin gene identified 17 beta-thalassemia variants. The most common mutation observed was T>G, G>C, C>A, and C>T in the exon 1 region of the HBB gene. Conclusion This study identifies the pattern of beta-thalassemia mutations, aiding in the prevention of the disorder through prenatal diagnosis and genetic counseling. Mutations can alter codon sequences, affecting protein production. Research highlights the importance of a primary prevention program to analyze mutations and sequence variations at the molecular level, thereby helping to address numerous genetic disorders.

Using SWATH-MS to identify new molecular biomarkers in gingival crevicular fluid for detecting periodontitis and its response to treatment.

To identify new biomarkers to detect untreated and treated periodontitis in gingival crevicular fluid (GCF) using sequential window acquisition of all theoretical mass spectra (SWATH-MS). GCF samples were collected from 44 periodontally healthy subjects and 40 with periodontitis (Stages III-IV). In the latter, 25 improved clinically 2 months after treatment. Samples were analysed using SWATH-MS, and proteins were identified by the UniProt human-specific database. The diagnostic capability of the proteins was determined with generalized additive models to distinguish the three clinical conditions. In the untreated periodontitis vs. periodontal health modelling, five proteins showed excellent or good bias-corrected (bc)-sensitivity/bc-specificity values of >80%. These were GAPDH, ZG16B, carbonic anhydrase 1, plasma protease inhibitor C1 and haemoglobin subunit beta. GAPDH with MMP-9, MMP-8, zinc-α-2-glycoprotein and neutrophil gelatinase-associated lipocalin and ZG16B with cornulin provided increased bc-sensitivity/bc-specificity of >95%. For distinguishing treated periodontitis vs. periodontal health, most of these proteins and their combinations revealed a predictive ability similar to previous modelling. No model obtained relevant results to differentiate between periodontitis conditions. New single and dual GCF protein biomarkers showed outstanding results in discriminating untreated and treated periodontitis from periodontal health. Periodontitis conditions were indistinguishable. Future research must validate these findings.