D-binding Protein Research Articles

Parathyroidectomy reduces inflammatory cytokines and increases vitamin D metabolites in patients with primary hyperparathyroidism

ContextPrimary hyperparathyroidism (PHPT) is accompanied by a decreased 25-hydroxyvitamin D (25OHD) and vitamin D binding protein (DBP). High parathyroid hormone (PTH) is associated with elevated interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1), yet the role of parathyroidectomy (PTX) on DBP and cytokines is not clear. ObjectiveTo prospectively evaluate the effect of PTX on inflammatory profiles, total and free 25OHD, and DBP in patients with PHPT. MethodsNewly diagnosed patients with PHPT were recruited in the study (n=70). Twenty-eight patients returned after PTX, 3 months later. Biochemical markers were measured before and after PTX. A group of age and BMI-matched healthy subjects were included as controls (n=70). ResultsPrior to PTX, patients had lower serum DBP (37.5±6.0 vs 41.5±6.1mg/dL, p<0.001) and total 25OHD (30.1±9.5 vs 33.3±7.9ng/mL, P<0.05), but similar free 25OHD when compared to controls. Serum IL-6, C-reactive protein (CRP), and MCP-1 were higher in PHPT patients (p<0.05), whereas interleukin-10 (IL-10) was similar to controls. PTX increased total and free 25OHD and DBP (p<0.001), and decreased serum IL-6 and MCP-1 (p<0.05), but not CRP and IL-10. Multiple regression analysis indicated that the preoperative PTH explained a significant portion of the variance of IL-6 and MCP-1 (p<0.05). ConclusionsThese findings suggest that PTH may upregulate the production of MCP-1 and IL-6 and downregulate circulating DBP in patients with PHPT, that are normalized by PTX. The exact effect of IL-6 and MCP-1 on DBP, vitamin D metabolites and the role on clinical outcomes in patients with PHPT is an area requiring further study.

Urinary Complement C3 and Vitamin D-Binding Protein Predict Adverse Outcomes in Patients with Acute Kidney Injury after Cardiac Surgery

Introduction: Acute kidney injury (AKI) is associated with adverse outcomes, including death and dialysis. The goal of this study was to identify prognostic biomarkers of AKI that could be used across multiple phenotypes of AKI and across different species. Methods: Liquid chromatography/tandem mass spectrometry analysis of urine samples from three species (human, rat, and mouse) and four etiologies of AKI identified five potential biomarkers, of which two were validated, complement C3 and vitamin D-binding protein, in a cohort of 157 patients that developed AKI following cardiothoracic surgery. We studied the relationship between the biomarker’s concentration in the urine and the development of a composite primary endpoint (stage 3 AKI within 10 days or death within 30 days). Results: Of the 153 patients who developed AKI following cardiovascular surgery, 17 met the combined primary outcome. The median concentration of urine complement C3 adjusted to urine creatinine had the best predictive value and was significantly higher in the primary outcome group than in the controls. Similarly, the median concentration of vitamin D-binding protein was higher in the primary outcome group. Conclusions: The studies provide proof in principle that cross-species discovery analyses could be a valuable tool for identifying novel prognostic biomarkers in AKI. Urine complement C3 and vitamin D-binding protein could be promising early predictors of adverse outcomes in patients who develop AKI after cardiac surgery.

Physiological changes in the regulation of calcium and phosphorus utilization that occur after the onset of egg production in commercial laying hens.

At the onset of egg production, physiological changes governing calcium and phosphorus utilization must occur to meet demands for medullary bone formation and eggshell mineralization. The objective of this study was to identify these changes and determine if they are influenced by dietary supplementation with 1α-hydroxycholecalciferol (AlphaD3™, Iluma Alliance). Commercial laying hens fed either a control or AlphaD3-supplemented diet beginning at 18 weeks of age were sampled at 18 (n = 8) and 31 weeks (n = 8/diet) to evaluate mRNA expression associated with calcium and phosphorus utilization in kidney, shell gland, ileum, and liver, circulating vitamin D3 metabolites, and bone quality parameters in humerus, tibia, and keel bone. Though diet did not heavily influence gene expression at 31 weeks, several significant differences were observed between 18- and 31-week-old hens. Heightened sensitivity to hormones regulating calcium and phosphorus homeostasis was observed at 31 weeks, indicated by increased parathyroid hormone receptor 1, calcium-sensing receptor, calcitonin receptor, and fibroblast growth factor 23 receptors in several tissues. Increased renal expression of 25-hydroxylase and vitamin D binding protein ( DBP ) at 31 weeks suggests kidney participates in local vitamin D3 25-hydroxylation and DBP synthesis after egg production begins. Biologically active 1,25(OH)2D3 was higher at 31 weeks, with correspondingly lower inactive 24,25(OH)2D3. Increased expression of plasma membrane calcium ATPase 1 and calbindin in kidney, shell gland, and ileum suggests these are key facilitators of calcium uptake. Elevated renal inorganic phosphorus transporter 1 and 2 and sodium-dependent phosphate transporter IIa at 31 weeks suggests increased phosphorus excretion following hyperphosphatemia due to bone breakdown for eggshell formation. Diet did influence bone quality parameters. Bone mineral density in both humerus and tibia was higher in AlphaD3-supplemented hens at 31 weeks. Tibial bone mineral content increased between 18 and 31 weeks, with AlphaD3-supplemented hens increasing more than control hens. Moreover, control hens exhibited diminished tibial breaking strength at 31 weeks compared to hens at 18 weeks, while AlphaD3-supplemented hens did not. Together, these results indicate supplementation with AlphaD3 enhanced bone mineralization during the medullary bone formation period and elucidate the adaptive pathways regulating calcium and phosphorus utilization after the onset of lay.

Investigation of the Relationship between Vitamin D Deficiency and Vitamin D-Binding Protein Polymorphisms in Severe COVID-19 Patients.

This study explores the association of vitamin D-binding protein (VDBP) gene polymorphisms, vitamin D levels, and the severity of COVID-19, including the need for intensive care unit (ICU) hospitalization. We analyzed a cohort of 56 consecutive age- and gender-matched adult COVID-19-positive patients and categorized them into three groups: outpatients with mild illness, inpatients with moderate disease, and ICU patients. We measured levels of free, total, and bioavailable 25-hydroxyvitamin D [25(OH)D], VDBP, and albumin. VDBP polymorphisms rs5488 and rs7041 were identified using real-time PCR. A significant proportion of ICU patients were vitamin D-deficient (56.25%) compared to outpatients (10%) and inpatients (5%) (p = 0.0003). ICU patients also had notably lower levels of VDBP (median: 222 mg/L) and total 25(OH)D (median: 18.8 ng/mL). Most patients carried heterozygous rs7041 (60.7%) and wild-type rs4588 (58.9%) genotypes. The distribution of rs7041 SNP varied significantly among groups (p = 0.0301), while rs4588 SNP distribution did not (p = 0.424). Heterozygous rs4588 patients had significantly lower VDBP levels (p = 0.029) and reduced bioavailable 25(OH)D compared to those with wild-type rs4588 (p = 0.020). Our findings indicate that VDBP gene polymorphisms, particularly rs7041 and rs4588, are associated with vitamin D status and the severity of COVID-19. The lower VDBP levels and bioavailable vitamin D in ICU patients suggest that these genetic variants may influence disease severity and hospitalization needs. These results highlight the potential role of VDBP polymorphisms in COVID-19 severity, suggesting that genetic screening could be valuable in assessing the risk of severe outcomes and guiding personalized treatment strategies.

The Role of Vitamin D Metabolism Genes and Their Genomic Background in Shaping Cyclosporine A Dosage Parameters after Kidney Transplantation.

Background: Kidney transplantation is followed by immunosuppressive therapy involving calcineurin inhibitors (CNIs) such as cyclosporin A. However, long-term high CNIs doses can lead to vitamin D deficiency, and genetic variations influencing vitamin D levels can indirectly impact the necessary CNIs dosage. This study investigates the impact of genetic variations of vitamin D binding protein (DBP) rs2282679 and CYP2R1 hydroxylase rs10741657 polymorphisms on the cyclosporin A dosage in kidney transplant recipients. Additional polymorphisims of genes that are predicted to influence the pharmacogenetic profile were included. Methods: Gene polymorphisms in 177 kidney transplant recipients were analyzed using data mining techniques, including the Random Forest algorithm and Classification and Regression Trees (C&RT). The relationship between the concentration/dose (C/D) ratio of cyclosporin A and genetic profiles was assessed to determine the predictive value of DBP rs2282679 and CYP2R1 rs10741657 polymorphisms. Results: Polymorphic variants of the DBP (rs2282679) demonstrated a strong predictive value for the cyclosporin A C/D ratio in post-kidney transplantation patients. By contrast, the CYP2R1 polymorphism (rs10741657) did not show predictive significance. Additionally, the immune response genes rs231775 CTLA4 and rs1800896 IL10 were identified as predictors of cyclosporin A response, though these did not result in statistically significant differences. Conclusions:DBP rs2282679 polymorphisms can significantly predict the cyclosporin A C/D ratio, potentially enhancing the accuracy of CNI dosing. This can help identify patient groups at risk of vitamin D deficiency, ultimately improving the management of kidney transplant recipients. Understanding these genetic influences allows for more personalized and effective treatment strategies, contributing to better long-term outcomes for patients.

Indian ASD probands with 25(OH)D and vitamin D binding protein deficiency exhibited higher severity

The severity of autism spectrum disorder (ASD) shows wide variations, though the reason remains unclear. Vitamin D (VitD) deficiency is considered a risk factor for ASD and its supplementation was reported to reduce symptom severity. Since VitD, either synthesized in the skin or absorbed from the food, is transported to the liver by the vitamin D binding protein (DBP), we have analyzed DBP genetic polymorphisms [rs7041 (A/C), rs4588 (G/T), and rs3755967 (C/T)] affecting DBP function [Case = 411; Control = 397], levels of plasma 25(OH)D and DBP [Case = 25; Control = 26], and DBP mRNA expression [Case = 74; Control = 44] in a group of Indo-Caucasoid ASD probands and neurotypical subjects. ASD probands with rs7041’CC’, rs4588 ‘TT’, and rs3755967 ‘TT’ genotypes exhibited higher scores for a few traits. Scores for Imitation and Listening response were also higher in the presence of the “A-T” haplotype (rs7041–rs4588). Plasma 25(OH)D and DBP levels as well as DBP mRNA expressions were significantly lower in the ASD probands as compared to the neurotypical subjects. We infer that DBP deficiency, in the presence of risk genetic variants, could be one of the reasons for the reported 25(OH)D deficiency of the ASD probands.

Relation of T Cell Profile with Vitamin D Receptor and Vitamin D-Binding Protein Gene Polymorphisms in Atopy.

Atopic diseases, including atopic dermatitis (AD) and allergic asthma (AA), are characterized by complex immune responses involving various T cells subsets and their cytokine profiles. It is assumed that single nucleotide polymorphisms (SNPs) in the Vitamin D receptor (VDR) gene and the Vitamin D-binding protein (GC) gene are related to the action of Vitamin D and, consequently, play a role in regulating the immune response. However, there is not enough data to unequivocally support the hypothesis about the relationship between T cells profile and VDR or GC SNPs. Two hundred sixty-six subjects (aged > 18 years) were involved in the study: 100 patients with mild or moderate AD, 85 patients with mild or moderate AA, and 81 healthy individuals. Blood cell counts were determined by standard methods. Flow cytometric analysis was used to evaluate CD4+ T-helper (Th) cell subtypes: Th2, Th1, Th17, and T regulatory (Treg) cells in peripheral blood. Measurements of cytokines, total immunoglobulin E (IgE), and Vitamin D levels in serum were evaluated by ELISA. Significantly higher levels of Th1, Th2, and Th17 cells, along with lower levels of Tregs, were found in patients with atopic diseases compared to healthy individuals. Additionally, higher serum levels of interleukin (IL) 5, IL-17A, and transforming growth factor-β1 (TGF-β1), as well as lower levels of IL-10, were observed in patients with atopic diseases than in control. The study established associations between VDR SNPs and immune profiles: the AA genotype of rs731236 was associated with increased Th2 and Th17 cells and a higher Th1/Th2 ratio; the GG genotype of rs731236 was linked to decreased serum IL-10 and TGF-β1 levels; and the TT genotype of rs11168293 was associated with increased IL-10 levels. Additionally, the GG genotype of GC gene SNP rs4588 was associated with reduced Th2 and Th17 lymphocytes, while the TT genotype of rs4588 was linked to decreased IL-10 levels. Furthermore, the CC genotype of rs7041 was associated with higher levels of Th2, Th17, IL-10, and IL-35, as well as reduced levels of TGF-β1, while the GG genotype of rs3733359 was associated with reduced IL-10 levels. In conclusion, our study demonstrates that the Vitamin D receptor gene single nucleotide polymorphisms rs731236 and rs11168293, along with polymorphisms in the Vitamin D-binding protein gene (rs4588, rs7041, rs3733359), are significantly associated with variations in T cell profiles in atopy. These variations may play a crucial role in promoting inflammation and provide insight into the genetic factors contributing to the pathogenesis of atopy.

Proteomic Profiling of HDL in Newly Diagnosed Breast Cancer Based on Tumor Molecular Classification and Clinical Stage of Disease.

The association between high-density lipoprotein (HDL) cholesterol and breast cancer (BC) remains controversial due to the high complexity of the HDL particle and its functionality. The HDL proteome was determined in newly diagnosed BC classified according to the molecular type [luminal A or B (LA or LB), HER2, and triple-negative (TN)] and clinical stage of the disease. Women (n = 141) aged between 18 and 80 years with BC, treatment-naïve, and healthy women [n = 103; control group (CT)], matched by age and body mass index, were included. Data-independent acquisition (DIA) proteomics was performed in isolated HDL (D = 1.063-1.21 g/mL). Results: Paraoxonase1, carnosine dipeptidase1, immunoglobulin mMu heavy chain constant region (IGHM), apoA-4, and transthyretin were reduced, and serum amyloid A2 and tetranectin were higher in BC compared to CT. In TNBC, apoA-1, apoA-2, apoC-2, and apoC-4 were reduced compared to LA, LB, and HER2, and apoA-4 compared to LA and HER2. ComplementC3, lambda immunoglobulin2/3, serpin3, IGHM, complement9, alpha2 lysine rich-glycoprotein1, and complement4B were higher in TNBC in comparison to all other types; complement factor B and vitamin D-binding protein were in contrast to LA and HER2, and plasminogen compared to LA and LB. In grouped stages III + IV, tetranectin and alpha2-macroglobulin were reduced, and haptoglobin-related protein; lecithin cholesterol acyltransferase, serum amyloid A1, and IGHM were increased compared to stages I + II. Conclusions: A differential proteomic profile of HDL in BC based on tumor molecular classification and the clinical stage of the disease may contribute to a better understanding of the association of HDL with BC pathophysiology, treatment, and outcomes.

The Effect of Phototherapy on Systemic Inflammation Measured with Serum Vitamin D-Binding Protein and hsCRP in Patients with Inflammatory Skin Disease.

Vitamin D plays a role in inflammatory skin disease, but the exact mechanisms and the clinical significance remain unclear. According to the free hormone hypothesis, it is the free concentration of 25-hydroxy vitamin D (25(OH)D) that is biologically active. Vitamin D-binding protein (DBP) acts as the major transporter of vitamin D in the circulation, and DBP concentration defines the free 25(OH)D levels. DBP levels are elevated in various inflammatory conditions, including psoriasis. Narrowband-ultraviolet B (NB-UVB) is the most widely used phototherapy and is an established first-line treatment for psoriasis and atopic dermatitis (AD), often used before proceeding to systemic treatment. The aim of this study was to investigate the influence of NB-UVB phototherapy on DBP and high-sensitivity C-reactive protein (hsCRP) levels, as markers of systemic inflammation, in inflammatory skin disease. Thirty adults (psoriasis (n = 20) and AD (n = 10)) were treated with NB-UVB. Serum DBP, hsCRP, total and free 25(OH)D, and 1,25-dihydroxy vitamin D (1,25(OH)2D) were measured before and after NB-UVB. Disease severity was assessed with Psoriasis Area and Severity Index (PASI), SCORing Atopic Dermatitis (SCORAD), and Visual Analogue Scale (VAS). DBP decreased in psoriasis patients and varied with no clear trend in AD patients. HsCRP decreased in both groups, but this did not reach statistical significance. PASI, SCORAD, and VAS improved, and vitamin D levels increased after NB-UVB. Sub-analysis indicated a better response to NB-UVB for patients with vitamin D deficiency and insufficiency compared to vitamin D-sufficient patients. The decrease in DBP after NB-UVB in psoriasis patients suggests a potential systemic anti-inflammatory effect of phototherapy. Measurement of vitamin D levels may potentially serve as a tool to identify patients who would derive the greatest benefit from NB-UVB phototherapy.

Exploring Candidate Gene Studies and Alexithymia: A Systematic Review.

Alexithymia is a trait involving difficulties in processing emotions. Genetic association studies have investigated candidate genes involved in alexithymia's pathogenesis. Therefore, the aim of the present study was to perform a systematic review of the genetic background associated with alexithymia. A systematic review of genetic studies of people with alexithymia was conducted. Electronic databases including PubMed, Scopus, and Web of Science were searched for the study purpose. We used the words "Alexithymia", "gene", "genetics", "variants", and "biomarkers". The present systematic review was performed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. We found only candidate gene studies. A total of seventeen studies met the eligibility criteria, which comprised 22,361 individuals. The candidate genes associated with alexithymia were the serotoninergic pathway genes solute carrier family 6 member 4 (SLC6A4), serotonin 1A receptor (HTR1A), and serotonin 1A receptor (HTR2A); the neurotransmitter metabolism genes dopamine receptor D2 (DRD2), ankyrin repeat and kinase domain containing 1 (ANKK1), catechol-o-methyltransferase (COMT), brain-derived neurotrophic factor (BDNF), and oxytocin receptor (OXTR); and other pathway genes, vitamin D-binding protein (VDBP), tumor protein P53 regulated apoptosis inducing protein 1 (TP53AIP1), Rho GTPase Activating Protein 32 (ARHGAP32), and transmembrane protein 88B (TMEM88B). The results of this study showed that only case-control gene studies have been performed in alexithymia. On the basis of our findings, the majority of alexithymia genes and polymorphisms in this study belong to the serotoninergic pathway and neurotransmitter metabolism genes. These data suggest a role of serotoninergic neurotransmission in alexithymia. Nevertheless, more and future research is required to learn about the role of these genes in alexithymia.

Exploring Canine Mammary Cancer through Liquid Biopsy: Proteomic Profiling of Small Extracellular Vesicles.

(Background). Canine mammary tumors (CMTs) have emerged as an important model for understanding pathophysiological aspects of human disease. Liquid biopsy (LB), which relies on blood-borne biomarkers and offers minimal invasiveness, holds promise for reflecting the disease status of patients. Small extracellular vesicles (SEVs) and their protein cargo have recently gained attention as potential tools for disease screening and monitoring. (Objectives). This study aimed to isolate SEVs from canine patients and analyze their proteomic profile to assess their diagnostic and prognostic potential. (Methods). Plasma samples were collected from female dogs grouped into CMT (malignant and benign), healthy controls, relapse, and remission groups. SEVs were isolated and characterized using ultracentrifugation (UC), nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Proteomic analysis of circulating SEVs was conducted using liquid chromatography-mass spectrometry (LC-MS). (Results). While no significant differences were observed in the concentration and size of exosomes among the studied groups, proteomic profiling revealed important variations. Mass spectrometry identified exclusive proteins that could serve as potential biomarkers for mammary cancer. These included Inter-alpha-trypsin inhibitor heavy chain (ITIH2 and ITI4), phosphopyruvate hydratase or alpha enolase (ENO1), eukaryotic translation elongation factor 2 (eEF2), actin (ACTB), transthyretin (TTR), beta-2-glycoprotein 1 (APOH) and gelsolin (GSN) found in female dogs with malignant tumors. Additionally, vitamin D-binding protein (VDBP), also known as group-specific component (GC), was identified as a protein present during remission. (Conclusions). The results underscore the potential of proteins found in SEVs as valuable biomarkers in CMTs. Despite the lack of differences in vesicle concentration and size between the groups, the analysis of protein content revealed promising markers with potential applications in CMT diagnosis and monitoring. These findings suggest a novel approach in the development of more precise and effective diagnostic tools for this challenging clinical condition.

Serum Afamin in Prediabetic Individuals in Association with Insulin Resistance and Glycemic Indices: A Case-Control Study

Background: Prediabetes is a metabolic disorder characterized by higher serum glucose levels than normal and below the diagnostic threshold for diabetes mellitus. Afamin is a glycoprotein mainly excreted from the liver and facilitates vitamin E transport. Afamin is one of the albumin gene family that includes albumin, α-Fetoprotein, and vitamin D-binding protein. Aim: This study aimed to evaluate serum afamin levels in prediabetic individuals and ascertain the association of serum afamin with insulin resistance and glycemic indices. Material and Methods: A case-control study was performed at Azadi Teaching Hospital, Kurdistan Region, Iraq, consisted of 88 participants, 44 prediabetic individuals and 44 apparently healthy individuals as a control group. Prediabetic individuals were obtained from relatives of patients with diabetes mellitus visiting Azadi Teaching Hospital, whereas, healthy individuals were chosen from the medical staff and college employees. The diagnosis of prediabetes was made according to the American Diabetes Association criteria. Serum afamin were assessed by Enzyme-Linked Immunosorbent Assay, while other biochemical parameters such as HbA1c, glucose and insulin were analyzed by Cobas 6000 (Roche, Hitachi/ Germany). Results: Mean level of serum afamin was higher in prediabetic individuals (115.31±62.74) compared to their level in the control group (91.57±43.46), with a statistically significant difference (p = 0.042). The mean age of prediabetics was (44.05±10.56) with males predominant (63.6%) and 70.5% of them were more than 40 years and 88.6% were obese. Conclusion: The study concluded the presence of higher mean serum afamin levels among prediabetic individuals compared to the healthy control.

Expression of Regulatory T Cell and Related Interleukins in Gingivitis Versus Stage 3, Grade B Generalized Periodontitis: Synergy or Cacophony—A Cross-Sectional Study

Abstract Aim: To raise “personalized periodontal diagnosis and prognosis” knowledge, Tregs, pro/anti-inflammatory interleukins (ILs) beside vitamin D-binding protein (VDBP) in serum and gingival cervical exudate of periodontally healthy individuals, plaque-induced gingivitis, and stage 3, grade B periodontitis patients were evaluated. Materials and Methods: An observational trial of different periodontal statuses according to 2018 periodontal classification was established from 60 subjects segregated into three equivalent groups (control periodontally healthy, gingivitis, and stage 3, grade B periodontitis). Peripheral blood and gingival crevicular fluid (GCF) were collected, to get GCF samples, inserted paper point in the pocket of the patient's teeth then the samples were placed with phosphate-buffered saline in Eppendorf. The peripheral blood was collected in ethylenediaminetetraacetic acid-coated vacutainer tubes. Frequency of CD4+ CD25+High Tregs was detected using flow cytometry. Cytokines were measured using an enzyme-linked immunosorbent assay. Mann–Whitney U test analysis was manipulated to distinguish the statistical discrepancies. Pearson’s correlation coefficient test was utilized to tie in the studied parameters. Result: Frequency of CD4+ CD25+High T cells were significantly ascendant in periodontitis than gingivitis and healthy (P ≤ 0.01; P = 0.04) and significantly superior in gingivitis than healthy (P = 0.01). There was no interdependence between systemic IL-21, IL-33, IL-22, IL-35, and the periodontal conditions except systemic VDBP, which significantly increased with the progression of the periodontal tissue inflammation. GCF compartments of IL-21, IL-33, and VDBP significantly increased with progression inflammation and GCF compartments of IL-22 and IL-35 significantly decreased with periodontal breakdown. Conclusion: Local increase of Treg is positively associated with increased local pro-inflammatory cytokines. This increment is more aggravated in periodontitis. Therefore, Tregs may have synergistic effects with periodontal disease progression.

Investigating Vitamin D-Binding Protein's Role in Childhood Health and Development.

Vitamin D-binding protein (DBP), also known as Gc-globulin, is a protein that affects several physiological processes, including the transport and regulation of vitamin D metabolites. Genetic polymorphisms in the DBP gene have a significant impact on vitamin D levels and may have implications for disease risk. DBP polymorphisms are linked to differential immune responses, which could influence the onset of juvenile diseases. This narrative review examines the various roles of DBP, with a focus on bone health, immunological regulation, and lipid metabolism in children. Chronic disorders affected by DBP polymorphisms include bone abnormalities, autoimmune diseases, cardiovascular issues, childhood asthma, allergies, cystic fibrosis, acute liver failure, celiac disease, inflammatory bowel disease, and chronic kidney disease. Future research should focus on identifying the processes that underpin the many roles that DBP plays and developing customized therapeutics to improve health outcomes in the juvenile population.

Vitamin D binding protein correlate with estrogen increase after administration of human chorionic gonadotropin but do not affect ovulation, embryo, or pregnancy outcomes.

Vitamin D binding protein (DBP) might increase substantially after ovarian stimulation and hence could be associated with IVF/ICSI outcomes because it determines the fraction of free bioavailable 25(OH) vitamin D. In this study, we aim to determine whether DBP is associated with E2 level after ovarian stimulation and IVF/ICSI outcomes. Post-hoc analysis of a prospective observational cohort. Single-center study. 2569 women receiving embryo transfer. None. The main outcomes were oocyte and embryo quality as well as pregnancy outcomes. DBP concentration correlates with E2 on hCG day (=day of inducing ovulation with hCG; correlation coefficient r = 0.118, P<0.001) and E2 x-fold change to baseline level (r = 0.108, P<0.001). DBP is also positively correlated with total 25(OH)D (r = 0.689, R2 = 0.475, P<0.001) and inversely with free 25(OH)D (r=-0.424, R2=0.179, P<0.001), meaning that E2-stimulated DBP synthesis results in a decrease of free 25(OH)D during ovarian stimulation. However, such alteration does not affect IVF/ICSI outcomes when considering confounding factors, such as the number and quality of oocytes nor embryo quality as well as pregnancy outcomes. DBP concentration correlates with the degree of E2 increase after ovarian stimulation. DBP is also positively correlated with total 25(OH)D and inversely with free 25(OH)D, suggesting that the proportion of free 25(OH)D decreases during ovarian stimulation caused by E2-stimulated DBP synthesis. However, such alteration does not affect clinical IVF/ICSI outcomes.

#3029 Vitamin D-binding protein: a candidate biomarker for CKD progression

Abstract Background and Aims The toxic effects of filtered proteins on the tubules cause a more rapid progression of disease in individuals with higher levels of proteinuria, suggesting the presence of “high-risk candidate” proteins that could contribute to CKD progression. In our previous cross-sectional proteomic study, vitamin D-binding protein (VTDB) showed a significant association with kidney function. However, its persistent expression as a urinary protein in CKD patients remains unknown. Therefore, our aim was to investigate the persistent expression of VTDB in CKD patients and healthy controls during the follow-up period. Method The urinary proteomics was investigated using liquid chromatography-mass spectrometry in 18 follow-up CKD patients with stages 1-3 and 15 follow-up healthy individuals. Data analysis was performed by Mascot-SwissProt and STATA software. Parametric and nonparametric statistics were used to analyze results and the relationship between baseline characteristics and proteomic profile. Exponentially Modified Protein Abundance Index (emPAI) was used to estimate peptide count of proteins. Results The participant's baseline characteristics are presented in Table 1. The median (IQR) follow-up time for all participants was 368 (250-472) days. A statistically significant difference was found in the initial emPAI of VTDB between the HC and CKD groups. However, there was no statistically significant difference in the follow-up emPAI of VTDB between the two groups. Notably, emPAI values of VTDP decreased over the follow-up period compared to the initial values. Correlation analysis (Table 2) showed that the elevated levels of urinary VTDB emPAI are associated with decreased levels of initial and follow-up eGFR. A higher negative percentage change (a decline in eGFR over time) was also associated with elevated levels of VTDB protein over the follow-up period. Also, urinary VTDP protein has demonstrated a significant positive correlation with 24 h proteinuria. Conclusion In this proteomics study cohort, we observed persistent expression of urinary VTDB protein during the follow-up period in CKD patients compared to healthy controls. Additionally, a statistically significant negative correlation between VTDB protein and eGFR was observed. These findings need further validation using different measurement tools for urinary VTDB assessments and in a larger cohort of CKD patients. Declaration We have no conflict of interest to disclose.

#1044 Quantitative analysis of dialytic protein loss with medium cut-off and high-flux membranes

Abstract Background and Aims Hemodialysis is an effective way for eliminating uremic retention products in patients with end-stage kidney disease. Medium cut-off membranes (MCO) were designed to enhance the dialytic removal of middle-sized molecules, such as beta-2 microglobulin (β2M). However, alongside these toxins, salutary proteins could also be lost. To better understand the spectrum of proteins cleared by MCO and high-flux (HF) dialyzers, we conducted qualitative and quantitative analysis of proteins in hemodialysis ultrafiltrate (UF). Method We established an ex vivo hemodialysis simulation system by using two Fresenius 2008T machines to concurrently dialyze a 2.5-liter human plasma reservoir for simultaneous testing of two dialyzers. We compared three dialyzers, including two HF dialyzers (Fresenius Medical Care Optiflux F180NR and FX CorAL 80), and an MCO membrane (Baxter Theranova 400; TH) (Fig. 1A). The blood flow rate was 400 mL/min, the dialysate flow rate was zero, and the ultrafiltration flow rate was 13 mL/min. UF samples were collected every 10 minutes from the UF line. Upon experiment completion at one-hour, residual filtrate was collected from the dialysate compartment. All samples were stored at −80°C until analysis. In total we conducted six dialysis simulations, each involving a concurrently tested dialyzer pair (Fig. 1B). UF samples underwent protein analysis (Bradford protein assay), albumin and creatinine measurement (Horiba® Pentra C400), liquid chromatography tandem mass spectrometry (LC-MS/MS)-based proteomics (Agilent® Q-TOF 6546), and immune-based protein assay (Luminex® Magpix). We analyzed the average of four sets of data obtained from the same dialyzer at the same time point. Results The loss of total protein and albumin was significantly greater with TH compared to the two HF dialyzers (Fig. 1C). Creatinine removal was similar across all dialyzers (Fig. 1D). The overall protein loss through F180NR and CorAL was comparable, while the protein loss through TH was up to 14-fold higher (811.7 ± 149.5 mg; Fig. 1E). Similar trends were observed for albumin. Albumin comprised 62% of the protein content in UF from TH, whereas it accounts for approximately 30% for HF dialyzers. We next employed label-free LC-MS and LC-MS/MS to identify and quantify proteins in 12 UF samples collected at the 20-minute point. Using Spectrum Mill software, we identified 244 proteins in the UF, 113 were accurately semi-quantified. The protein intensity ratios of TH-to- F180NR, TH-to-CorAL, and CorAL-to-F180NR for these 113 proteins are presented in Fig. 2A-C. Each gray dot on the plot corresponds to a specific protein. In line with the total protein and albumin quantification, MS proteomics analysis consistently revealed a greater loss of every identified protein by TH compared to both HF dialyzers. The median protein intensity ratio of TH-to-F180NR and TH-to-CorAL was 9.14 and 8.25, respectively. Importantly, TH not only removed middle-molecules such as β2M, but also showed a higher loss of salutary proteins. For instance, our data indicate a 9- to 16-fold difference in the level of albumin, haptoglobin, and vitamin D-binding protein between TH and HF dialyzers. Protein loss did not differ between F180NR and CorAL. To validate the accuracy of the MS quantification, we quantified seven proteins using immune-based assays in all UF samples at the 20-minute point. The result revealed a strong consistency between MS data and other methods (Fig. 2D). Conclusion We established an ex vivo system to concurrently test two dialyzers and implemented a robust proteomics workflow for a direct comparison of protein loss in the UF. Our data comprehensively and consistently indicate a greater extent of protein loss with MCO compared to HF, including the loss of salutary proteins. Further research is warranted to explore the clinical consequences of the enhanced loss of salutary proteins.

Association of serum 25-hydroxyvitamin D levels, vitamin D-binding protein levels, and diabetes mellitus: Two-sample Mendelian randomization.

Studies have suggested that Vitamin D deficiency is associated with the occurrence of both type 1 and type 2 diabetes, and that vitamin D-binding proteins (VDBP) are necessary for metabolic stress in pancreatic α-cells. However, the causal relationship between serum 25-hydroxyvitamin D [25(OH)D] levels, VDBP, and the risk of diabetes mellitus (DM) remains unclear. Mendelian randomization (MR) was used to investigate the causal relationship between 25(OH)D, VDBP, and DM. Relevant recent data were downloaded from the NHGRI-EBI Catalog of published genome-wide association studies (GWAS) and filtered for single nucleotide polymorphisms (SNPs). We used multiple MR methods, including inverse variance weighting (IVW), and performed sensitivity analyses to detect whether pleiotropy or heterogeneity biased the results. There was a causal relationship between genetically predicted VDBP levels and serum 25(OH)D levels, and serum 25(OH)D levels increased with increasing VDBP levels (IVW: β = 0.111, OR = 1.117, 95% CI:1.076-1.162, P = 1.41 × 10-8). There was no causal relationship between the genetically predicted VDBP levels, serum 25(OH)D levels, and DM (VDBP: IVW β:0.001, OR:1.001, 95% CI:0.998-1.003, P > .05; 25(OH)D: IVW β: -0.009, OR:0.991, 95% CI:0.982-1.001, P = .068). Sensitivity analysis indicated that horizontal pleiotropy was unlikely to bias causality in this study. MR analysis results demonstrated a positive causal relationship between VDBP levels and serum 25(OH)D levels in the European population. The 25(OH)D and VDBP levels were not causally related to an increased risk of diabetes.

The Role of Vitamin D-Binding Protein, and Procalcitonin in Patients with Arthritis on Vitamin D

The Role of Vitamin D-Binding Protein, and Procalcitonin in Patients with Arthritis on Vitamin D

Vitamin D(3) auto-/paracrine system in rat brain relating to vitamin D(3) status in experimental type 2 diabetes mellitus

Growing evidence suggests that vitamin D3 (D3, cholecalciferol) deficiency and impaired signaling of the hormonally active form of D3, 1α,25(OH)2D3 (1,25D3), through its cellular receptor (VDR) can be significant risk factors for the development of numerous multifactorial diseases, including diabetes. Our investigation was aimed at researching the D3 status in relation to the state of the D3 auto-/paracrine system in the brain and clarifying the effectiveness of the therapeutic use of D3 as a neuroprotective agent in experimental type 2 diabetes mellitus (T2DM). T2DM was induced in male Wistar rats by a combination of a high fat diet and a low dose of streptozotocin (25 mg/kg BW). Diabetic animals were treated with or without cholecalciferol (1,000 IU/kg BW, 30 days). The content of 25-hydroxyvitamin D3 (25D3) in blood serum and brain tissue was determined by ELISA. Analysis of mRNA expression of CYP24A1 and CYP27B1 genes was performed by RT-PCR. Protein levels of VDR, vitamin D3 binding protein (VDBP), CYP27B1 and CYP24A1 were investigated by Western blotting. A significant T2DM-associated decrease in the content of 25D3 in the blood serum was revealed, which correlated with a reduced content of this metabolite in the brain tissue. Impaired D3 status in animals with T2DM was accompanied by an increase in the levels of mRNA and protein of both 25D3 lα-hydroxylase (CYP27B1) and 1,25-hydroxyvitamin D3-24-hydroxylase (CYP24A1), which, respectively, provide local formation and degradation in the nervous tissue of the hormonally active form of D3 – 1,25D3. At the same time, a significant T2DM-induced down-regulation of the brain content of VDBP was shown. In addition, diabetes caused a slight increase in the protein expression of the VDR, through which the auto-/paracrine effects of 1,25D3 are realized in the brain. We have established a complete or partial corrective effect of cholecalciferol on D3 status, its bioavailability in the CNS and the level of protein expression of CYP27B1 and CYP24A1 in the brain of rats with T2DM. Abnormal D3 status in animals with T2DM was accompanied by compensatory changes in the expression of key components of the auto-/paracrine vitamin D3 system. Cholecalciferol was demonstrated to be partially effective in counteracting the impairments caused by T2DM. Keywords: 25-hydroxyvitamin D3, brain, type 2 diabetes, vitamin D3, vitamin D3 auto-/paracrine system