Population-specific validation and comparison of the performance of 77- and 313-variant polygenic risk scores for breast cancer risk prediction.

BACKGROUND: The polygenic risk score (PRS) allows the quantification of the polygenic effect of many low-penetrance alleles on the risk of breast cancer (BC). This study aimed to evaluate the performance of two sets comprising 77 or 313 low-penetrance loci (PRS77 and PRS313) in patients with BC in the Czech population. METHODS: In a retrospective case-control study, variants were genotyped from both the PRS77 and PRS313 sets in 1329 patients with BC and 1324 noncancer controls, all women without germline pathogenic variants in BC predisposition genes. Odds ratios (ORs) were calculated according to the categorical PRS in individual deciles. Weighted Cox regression analysis was used to estimate the hazard ratio (HR) per standard deviation (SD) increase in PRS. RESULTS: The distributions of standardized PRSs in patients and controls were significantly different (p < 2.2 × 10-16) with both sets. PRS313 outperformed PRS77 in categorical and continuous PRS analyses. For patients in the highest 2.5% of PRS313, the risk reached an OR of 3.05 (95% CI, 1.66-5.89; p = 1.76 × 10-4). The continuous risk was estimated as an HRper SD of 1.64 (95% CI, 1.49-1.81; p < 2.0 × 10-16), which resulted in an absolute risk of 21.03% at age 80 years for individuals in the 95th percentile of PRS313. Discordant categorization into PRS deciles was observed in 248 individuals (9.3%). CONCLUSIONS: Both PRS77 and PRS313 are able to stratify individuals according to their BC risk in the Czech population. PRS313 shows better discriminatory ability. The results support the potential clinical utility of using PRS313 in individualized BC risk prediction.

Circulating perturbation of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is associated to cardiac remodeling and NLRP3 inflammasome in cardiovascular patients with insulin resistance risk.

Lipidome perturbation occurring during meta-inflammation is associated to left ventricle (LV) remodeling though the activation of the NLRP3 inflammasome, a key regulator of chronic inflammation in obesity-related disorders. Little is known about phosphatidylcholine (PC) and phosphatidylethanolamine (PE) as DAMP-induced NLRP3 inflammasome. Our study is aimed to evaluate if a systemic reduction of PC/PE molar ratio can affect NLRP3 plasma levels in cardiovascular disease (CVD) patients with insulin resistance (IR) risk. Forty patients from IRCCS Policlinico San Donato were enrolled, and their blood samples were drawn before heart surgery. LV geometry measurements were evaluated by echocardiography and clinical data associated to IR risk were collected. PC and PE were quantified by ESI-MS/MS. Circulating NLRP3 was quantified by an ELISA assay. Our results have shown that CVD patients with IR risk presented systemic lipid impairment of PC and PE species and their ratio in plasma was inversely associated to NLRP3 levels. Interestingly, CVD patients with IR risk presented LV changes directly associated to increased levels of NLRP3 and a decrease in PC/PE ratio in plasma, highlighting the systemic effect of meta-inflammation in cardiac response. In summary, PC and PE can be considered bioactive mediators associated to both the NLRP3 and LV changes in CVD patients with IR risk.

Alarmins and Related Molecules in Elective Surgery.

Surgery is associated with alterations of alarmins' and related molecules' levels. The aim of this study was to investigate which biomarkers are most involved in surgery. The studied group consisted of 58 patients with inguinal or umbilical hernia or cholecystolithiasis and 21 healthy controls for compa-rison. We also added seven acute patients with appendicitis, cholecystitis and incarcerated hernia. Serum concentrations of soluble receptor of advanced glycation end-products (sRAGE), extracellular newly identified receptor for advanced glycation end-products binding protein (EN-RAGE), calprotectin, high mobility group box 1 (HMGB1) and interleukin 6 (IL-6) were analysed by ELISA before and after surgery. Preoperative concentrations of calprotectin were significantly decreased while concentrations of sRAGE were significantly increased in patients compared to controls; the concentrations of EN-RAGE and HMGB1 did not differ significantly. IL-6 levels were undetectable in elective patients preoperatively and in controls. Postoperatively, there was a significant increase of EN-RAGE, calprotectin, HMGB1, and IL-6 and a significant decrease of sRAGE compared to preoperative levels. In acute patients, all tested molecules except for sRAGE were significantly increased preoperatively, and sRAGE was significantly decreased. In contrast, after surgery, we could observe a further increase in IL-6; the other biomarkers did not differ significantly. We can conclude that the concentrations of all tested biomarkers are significantly influenced by elective surgery. The postoperative levels of all tested molecules increase except for sRAGE, whose level is significantly decreased after surgery. In acute states, these molecules are already increased, and the influence of surgery is, apart from IL-6, insignificant.

Unveiling IL-33/ST2 Pathway Unbalance in Cardiac Remodeling Due to Obesity in Zucker Fatty Rats.

Obesity is an epidemic condition linked to cardiovascular disease severity and mortality. Fat localization and type represent cardiovascular risk estimators. Importantly, visceral fat secretes adipokines known to promote low-grade inflammation that, in turn, modulate its secretome and cardiac metabolism. In this regard, IL-33 regulates the functions of various immune cells through ST2 binding and-following its role as an immune sensor to infection and stress-is involved in the pro-fibrotic remodeling of the myocardium. Here we further investigated the IL-33/ST2 effects on cardiac remodeling in obesity, focusing on molecular pathways linking adipose-derived IL-33 to the development of fibrosis or hypertrophy. We analyzed the Zucker Fatty rat model, and we developed in vitro models to mimic the adipose and myocardial relationship. We demonstrated a dysregulation of IL-33/ST2 signaling in both adipose and cardiac tissue, where they affected Epac proteins and myocardial gene expression, linked to pro-fibrotic signatures. In Zucker rats, pro-fibrotic effects were counteracted by ghrelin-induced IL-33 secretion, whose release influenced transcription factor expression and ST2 isoforms balance regulation. Finally, the effect of IL-33 signaling is dependent on several factors, such as cell types' origin and the balancing of ST2 isoforms. Noteworthy, it is reasonable to state that considering IL-33 to have a unique protective role should be considered over-simplistic.

CSF Markers of Oxidative Stress Are Associated with Brain Atrophy and Iron Accumulation in a 2-Year Longitudinal Cohort of Early MS.

In this prospective longitudinal study, we quantified regional brain volume and susceptibility changes during the first two years after the diagnosis of multiple sclerosis (MS) and identified their association with cerebrospinal fluid (CSF) markers at baseline. Seventy patients underwent MRI (T1 and susceptibility weighted images processed to quantitative susceptibility maps, QSM) with neurological examination at the diagnosis and after two years. In CSF obtained at baseline, the levels of oxidative stress, products of lipid peroxidation, and neurofilaments light chain (NfL) were determined. Brain volumetry and QSM were compared with a group of 58 healthy controls. In MS patients, regional atrophy was identified in the striatum, thalamus, and substantia nigra. Magnetic susceptibility increased in the striatum, globus pallidus, and dentate and decreased in the thalamus. Compared to controls, MS patients developed greater atrophy of the thalamus, and a greater increase in susceptibility in the caudate, putamen, globus pallidus and a decrease in the thalamus. Of the multiple calculated correlations, only the decrease in brain parenchymal fraction, total white matter, and thalamic volume in MS patients negatively correlated with increased NfL in CSF. Additionally, negative correlation was found between QSM value in the substantia nigra and peroxiredoxin-2, and QSM value in the dentate and lipid peroxidation levels.

Increased Transferrin Sialylation Predicts Phenoconversion in Isolated REM Sleep Behavior Disorder.

BACKGROUND: Sialic acid-protein interactions are involved in regulating central nervous system immunity; therefore, derangements in sialylation could be involved in neurodegeneration. OBJECTIVES: We evaluate the differences in serum transferrin sialylation in prodromal and early-stage Parkinson's disease (PD), its relation to substantia nigra degeneration, and the risk of phenoconversion to manifest disease. METHODS: Sixty treatment-naive PD patients; 72 polysomnography-confirmed isolated rapid eye movement sleep behavior disorder (iRBD) patients, that is, patients with prodromal synucleinopathy; and 46 healthy volunteers aged ≥45 years and drinking ≤60 standard drinks per month were included. The proportion of serum low-sialylated, carbohydrate-deficient transferrin (CDT) isoforms was assessed using high-performance liquid chromatography, and the values were adjusted for alcohol intake (CDTadj ). Dopamine transporter single-photon emission computed tomography (DaT-SPECT) imaging was performed. In iRBD, phenoconversion risk of DaT-SPECT and CDTadj was evaluated using Cox regression adjusted for age and sex. RESULTS: Median CDTadj was lower in PD (1.1 [interquartile range: 1.0-1.3]%) compared to controls (1.2 [1.1-1.6]%) (P = 0.001). In iRBD, median CDTadj was lower in subjects with abnormal (1.1 [0.9-1.3]%) than normal (1.3 [1.2-1.6]%) DaT-SPECT (P = 0.005). After a median 44-month follow-up, 20% of iRBD patients progressed to a manifest disease. Although iRBD converters and nonconverters did not significantly differ in CDTadj levels (P = 0.189), low CDTadj increased the risk of phenoconversion with hazard ratio 3.2 (P = 0.045) but did not refine the phenoconversion risk associated with abnormal DaT-SPECT yielding hazard ratio 15.8 (P < 0.001). CONCLUSIONS: Decreased serum CDTadj is associated with substantia nigra degeneration in synucleinopathies. iRBD patients with low CDTadj are more likely to phenoconvert to manifest disease. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.

Novel biochemical markers for non-invasive detection of pancreatic cancer.

To identify non-invasive biomarkers of non-metastatic pancreatic cancer (PC), the blood from 186 patients (PC n=28; DM-diabetes mellitus n=60; ChP-chronic pancreatitis n=47; healthy controls n=51) was analyzed for 58 candidate biomarkers. Their effectiveness to identify PC was compared with CA19-9. Panel defined by Random-forest (RF) analysis (CA19-9, AAT, IGFBP2, albumin, ALP, Reg3A, HSP27) outperforms CA19-9 in discrimination of PC from DM (AUC 0.92 vs. 0.82). Panel (S100A11, CA72-4, AAT, CA19-9, CB, MMP-7, S100P-s, Reg3A) is better in discrimination PC from ChP than CA19-9 (AUC 0.90 vs. 0.75). Panel (MMP-7, Reg3A, sICAM1, OPG, CB, ferritin) is better in discrimination PC from healthy controls than CA19-9 (AUC 0.89 vs. 0.78). Panel (CA19-9, S100P-pl, AAT, albumin, adiponectin, IGF-1, MMP7, S100A11) identifies PC among other groups better than CA19-9 (AUC 0.91 vs. 0.80). Panel defined by logistic regression analysis (prealbumin, IGFBP-2, DJ-1, MIC-1, CA72-4) discriminates PC from DM worse than CA19-9 (AUC 0.80 vs. 0.82). Panel (IGF-1, S100A11, Reg1alfa) outperforms CA19-9 in discrimination PC from ChP (AUC 0.76 vs. 0.75). Panel (IGF-2, S100A11, Reg3A) outperforms CA19-9 in discrimination PC from healthy controls (AUC 0.95 vs. 0.78). Panel (albumin, AAT, S100P-serum, CRP, CA19-9, TFF1, MMP-7) outperforms CA19-9 in identification PC among other groups (AUC 0.89 vs. 0.8). The combination of biomarkers identifies PC better than CA19-9 in most cases. S100A11, Reg3A, DJ-1 were to our knowledge identified for the first time as possible serum biomarkers of PC.

Retinoic acid associates with mortality of patients on long-term hemodialysis.

BACKGROUND: Retinol concentrations in serum are significantly higher in patients on hemodialysis (HD) compared to healthy controls. Its lower concentrations have been reported to be an independent predictor of mortality. ATRA - all-trans retinoic acid - is an important compound related to retinol. The objective was to determine ATRA concentrations in serum and to find their association with the prognosis of patients on long-term HD. METHODS: ATRA was determined by high-performance liquid chromatography in a group of 247 HD patients (follow-up five years) and 54 healthy controls. RESULTS: Although serum retinol concentrations were higher in the studied cohort of HD patients, ATRA was lower - median 1.13 (interquartile range 0.90-1.60) ng/mL in HD patients versus 1.42 (1.08-1.63) ng/mL in healthy controls, p = 0.02. Lower ATRA was significantly related to overall mortality of HD patients (HR (95%CI) 0.63 (0.47-0.85) per interquartile range, p = 0.003). The best prognosis was observed in patients with concentrations of both ATRA and retinol above the median (p = 0.003). CONCLUSIONS: We detected decreased retinoic acid levels in HD patients compared to healthy controls. Lower concentrations of ATRA represent a significant predictor of mortality and provide additional information to retinol.

Osteopontin: The Molecular Bridge between Fat and Cardiac-Renal Disorders.

Osteopontin (OPN) is a multifaceted matricellular protein, with well-recognized roles in both the physiological and pathological processes in the body. OPN is expressed in the main organs and cell types, in which it induces different biological actions. During physiological conditioning, OPN acts as both an intracellular protein and soluble excreted cytokine, regulating tissue remodeling and immune-infiltrate in adipose tissue the heart and the kidney. In contrast, the increased expression of OPN has been correlated with the severity of the cardiovascular and renal outcomes associated with obesity. Indeed, OPN expression is at the "cross roads" of visceral fat extension, cardiovascular diseases (CVDs) and renal disorders, in which OPN orchestrates the molecular interactions, leading to chronic low-grade inflammation. The common factor associated with OPN overexpression in adipose, cardiac and renal tissues seems attributable to the concomitant increase in visceral fat size and the increase in infiltrated OPN+ macrophages. This review underlines the current knowledge on the molecular interactions between obesity and the cardiac-renal disorders ruled by OPN.

Matrix Metalloproteinases in Renal Diseases: A Critical Appraisal.

Matrix metalloproteinases (MMPs) are endopeptidases within the metzincin protein family that not only cleave extracellular matrix (ECM) components, but also process the non-ECM molecules, including various growth factors and their binding proteins. MMPs participate in cell to ECM interactions, and MMPs are known to be involved in cell proliferation mechanisms and most probably apoptosis. These proteinases are grouped into six classes: collagenases, gelatinases, stromelysins, matrilysins, membrane type MMPs, and other MMPs. Various mechanisms regulate the activity of MMPs, inhibition by tissue inhibitors of metalloproteinases being the most important. In the kidney, intrinsic glomerular cells and tubular epithelial cells synthesize several MMPs. The measurement of circulating MMPs can provide valuable information in patients with kidney diseases. They play an important role in many renal diseases, both acute and chronic. This review attempts to summarize the current knowledge of MMPs in the kidney and discusses recent data from patient and animal studies with reference to specific diseases. A better understanding of the MMPs' role in renal remodeling may open the way to new interventions favoring deleterious renal changes in a number of kidney diseases.

Polymorphisms of the receptor for advanced glycation end products and glyoxalase I and long-term outcome in patients with breast cancer.

Receptor for advanced glycation end products and glyoxalase I metabolizing advanced glycation end product precursors may play important role in the pathogenesis and progression of cancer. Potential relation between soluble forms of receptor for advanced glycation end products (sRAGE), receptor for advanced glycation end products, glyoxalase I polymorphisms, and long-term outcome (median follow-up of 10.3 years) was studied in 116 patients with breast cancer. Gly82Ser and 2184 A/G RAGE polymorphisms were related to the mortality due to the breast cancer and -419 A/C glyoxalase I polymorphism was related to the overall mortality of the patients suggesting their role not only in the risk of breast cancer but also in the outcome of patients with breast cancer.

Pregnancy-Associated Plasma Protein A2 in Hemodialysis Patients: Significance for Prognosis.

BACKGROUND: Pregnancy-associated plasma protein A (PAPP-A) is associated with adverse outcome of long-term hemodialysis patients (HD). The aim of the study was to test whether its homolog pregnancy-associated plasma protein A2 (PAPP-A2) can be detected in serum of HD patients and to define its significance. METHODS: The studied group consisted of 102 long-term HD patients and 25 healthy controls. HD patients were prospectively followed up for five years (2009-2014). PAPP-A2 was measured by surface plasmon resonance biosensor, PAPP-A by time resolved amplified cryptate emission. RESULTS: PAPP-A2, similarly as PAPP-A, was significantly increased in HD patients (median (interquartile range)) PAPP-A2: 6.2 (2.6-10.8) ng/mL, vs. 3.0 (0.7-5.9) ng/mL, p=0.006; PAPP-A: 18.9 (14.3-23.4) mIU/L, vs. 9.5 (8.4-10.5) mIU/L, p<0.001). In HD patients, PAPP-A2 correlated weakly but significantly with PAPP-A (τ=0.193, p=0.004). Unlike PAPP-A, PAPP-A2 was not significant for prognosis of HD patients when tested alone. There was a significant interaction between PAPP-A and PAPP-A2 on the mortality due to infection of HD patients (p=0.008). If PAPP-A was below median, mortality due to infection was significantly higher for patients with PAPP-A2 values above median than for patients with low PAPP-A2 levels (p=0.011). CONCLUSION: PAPP-A2 is increased in HD patients and interacts with PAPP-A on patients´ prognosis.

Comparison of DNA isolation using salting-out procedure and automated isolation (MagNA system).

Isolation of genomic DNA is a key step in genetic analysis. The aim of the study was to evaluate the suitability of isolation of DNA from peripheral blood with manual salting-out procedure and automated MagNA system under specific conditions. The impact of storage conditions, type of material (whole blood or blood cells), and method used for DNA extraction were evaluated in terms of DNA yield, its purity, and integrity. Fresh material, and material stored at 2-8°C for 1-4 weeks and frozen at -80°C were tested. For fresh samples, salting-out method gives higher yield than MagNA, irrespectively, on material used. Neither the yield of salting-out method nor its purity decreases during the storage of the samples in the fridge (2-8°C) during 4 weeks. Concerning MagNA, storage of blood cells in the fridge decreases the yield of DNA as well as its purity. For frozen samples, for whole blood, MagNA gives better results while for blood cells, salting-out method seems to be better. For fresh samples, salting-out method is the preferred one, and both whole blood and blood cells can be used. For frozen samples, the preferred method depends on the material.

Surface plasmon resonance biosensor for detection of pregnancy associated plasma protein A2 in clinical samples.

Pregnancy associated plasma protein A2 (PAPP-A2) is a metalloproteinase that plays multiple roles in fetal development and post-natal growth. Here we present a novel surface plasmon resonance (SPR) biosensor for the rapid and quantitative detection of PAPP-A2 in blood samples. This biosensor uses a single surface referencing approach and a sandwich assay with functionalized gold nanoparticles for signal enhancement. We demonstrate that this SPR biosensor enables the detection of PAPP-A2 in 30 % blood plasma at levels as low as 3.6 ng/mL. We also characterize the performance of the biosensor and evaluate its cross-reactivity to a PAPP-A analogue. Finally, we utilize this SPR biosensor for the detection of PAPP-A2 in blood serum from two groups of subjects: pregnant women and healthy non-pregnant women and men. Graphical Abstract Temporal sensor response corresponding to respective steps of the assay for detection of PAPP-A2 in buffer.

Polymorphisms of the receptor for advanced glycation end-products and glyoxalase I in patients with renal cancer.

The receptor for advanced glycation end products (RAGE) and its ligands are involved in the pathogenesis of cancer. Glyoxalase I (GLO1) is an enzyme which detoxifies advanced glycation end product (AGE) precursors. The aim of the study was to find out the relationship between four polymorphisms (single nucleotide polymorphism, SNP) of the RAGE gene (AGER) and one SNP of the GLO1 gene and clear cell renal cancer (ccRCC). All polymorphisms (rs1800625 RAGE -429T/C, rs1800624 -374T/A, rs3134940 2184A/G, rs2070600 557G/A (G82S), and GLO1 rs4746 419A/C(E111A)) were determined by PCR-RFLP in 214 patients with ccRCC. A group of 154 healthy subjects was used as control. We found significant differences in the allelic and genotype frequencies of GLO1 E111A (419A/C) SNP between patients and controls-higher frequency of the C allele in ccRCC-58.6 vs. 44.5% in controls, OR (95% CI) 1.77 (1.32-2.38), p = 0.0002 (corrected p = 0.001); OR (95% CI) CC vs. AA 2.76 (1.5-4.80), p = 0.0004 (corrected p = 0.002); and AC+CC vs. AA 2.03 (1.23-3.30), p = 0.0034 (corrected p = 0.017). High aggressiveness of the tumor (grade 4) was associated with the presence of C allele RAGE -429T/C SNP (original p = 0.001, corrected p = 0.005) and G allele RAGE 2184A/G SNP (p < 0.001 and p < 0.005), and for genotypes RAGE -429CC (original p = 0.008, corrected p = 0.04) and RAGE 2184GG SNP (original p = 0.005, corrected p = 0.025). Our results demonstrate the link of E111A GLO1 SNP to the presence of the tumor and the connection of RAGE -429T/C and 2184A/G SNPs with the aggressiveness of the tumor. Further studies are required, especially with respect to potential therapeutic implications.

Diagnostic Importance of Selected Protein Serum Markers in the Primary Diagnostics of Prostate Cancer.

OBJECTIVE: To determine a predictive model for the primary diagnosis of prostate cancer (PC) based on a multiple serum biomarker assay. MATERIAL AND METHODS: Between August 2011 and February 2013, a total of 387 prostate biopsies were performed. Serum or plasma concentrations of 22 biomarkers (neopterin, IGF-1, IGFBP-2, IGFBP-3, sarcosine, endoglin, TGF-ß1, periostin, sPLA2-IIa, chromogranin A, ZAG2, clusterin, PSP94, PSP94bp, leptin, cathepsin D, hepsin, KLK11, PSMA, AMACR, CRISP3 and A1AT) were determined. Biomarker levels were correlated with the prostate biopsy results. Several statistical models for PC detection were created. RESULTS: A total of 167 of the 373 evaluated patients (44.8%) were diagnosed with PC. None of the tested biomarkers reached statistical significance using the univariate analysis. However, the level of serum clusterin was not associated with any other tested parameter. Several basic models showed a higher positive predictive value than individual parameters. Addition of serum clusterin to the base model with prostate-specific antigen, digital rectal exam and prostate size significantly improved the area under curve value (0.723 vs. 0.716). CONCLUSION: Our findings suggested that multiple serum assays based on some promising markers may only have a limited practical benefit for the prediction of PC in the prostate biopsy.

Panel of Urinary Diagnostic Markers for Non-Invasive Detection of Primary and Recurrent Urothelial Urinary Bladder Carcinoma.

OBJECTIVES: To determine the combination of urinary protein markers for noninvasive detection of primary and recurrent urothelial bladder carcinomas. METHODS: Urinary concentrations of 27 biomarkers (NSE, ATT, AFABP, Resistin, Midkine, Clusterin, Uromodulin, ZAG2, HSP27, HSP 60, NCAM1/CD56, Angiogenin, Calreticulin, Chromogranin A, CEACAM1, CXCL1, IL13Ra2, Progranulin, VEGFA, CarbAnhydIX, Annexin-V, TIM4, Galectin1, Cystatin B, Synuclein G, ApoA1 and ApoA2) were assessed by enzyme-linked immunosorbent assay or by electrochemiluminiscence immunoassay. RESULTS: During the primary diagnostics, a group of 70 patients with primary occurrence of bladder cancer and 49 healthy control subjects were compared. For this clinical situation, the most accurate combination proved to be the combination of cytology with markers Midkine and Synuclein G (sensitivity 91.8%, specificity 97.5%). During the monitoring of patients with non-muscle invasive bladder cancer (NMIBC), a group of 44 patients with cancer recurrence was compared with the group of 61 patients with a history of NMIBC without current disease. For this clinical situation, the most accurate combination proved to be the combination of cytology and erythrocytes count in urine sediment with markers Midkine, ZAG2, CEACAM1, and Synuclein G (sensitivity 92.68%, specificity 90.16%). A lower accuracy of the diagnostic panel and the necessity to use more markers in the case of recurrence was connected with a different structure of patients. CONCLUSIONS: Multi-marker test can significantly improve the bladder cancer detection both during the primary diagnostics and monitoring of patients with NMIBC. This outcome should result in other, larger studies.

[AGEs and RAGE - advanced glycation end-products and their receptor in questions and answers]. / AGEs a RAGE - konecné produkty pokrocilé glykace a jejich receptor v otázkách a odpovedích.

Advanced glycation end products (AGEs) play an important role in the pathogenesis of chronic diseases and their complications, especially diabetic complications, atherosclerosis, complications of chronic kidney diseases and neurodegenerative diseases. These substances are formed via non-enzymatic glycation and their formation is potentiated in case of carbonyl stress. AGEs are represented by a heterogeneous group of compounds, e.g. carboxymethyllysine, pentosine, methylglyoxallysin dimer, vesperlysine, imidazolones etc. AGEs can modify proteins and so change their physical and chemical properties and can act also via specific receptors, among them RAGE (receptor for advanced glycation end products) is the best known but not the unique one. RAGE is a multiligand receptor capable to bind also HMGB1 (high mobility group box protein 1), S100 proteins or amyloid fibrils. RAGE - ligand interactions results to activation of a variety of signaling pathways including oxidative stress and activation of nuclear factor κB and subsequent proinflammatory response depending on the cell type. AGEs and RAGE together with further mechanisms - hexosamine pathway, polyol pathway, lipid metabolism disorder, activation of proteinkinase C, oxidative stress and inflammatory reaction take part in the pathogenesis of diabetic complications. Terapeuticaly it is possible to decrease endogenous formation of AGEs, influence the AGEs intake to the organism and their absorption in the intestine or stimulate their degradation.Key words: AGEs - advanced glycation end-products - carbonyl stress - diabetes mellitus - inflammation - oxidative stress - RAGE - receptor for AGEs - sRAGE.

[Receptor pro konecné produkty pokrocilé glykace (RAGE) - klícový hrác diabetické angiopatie?]. / Receptor pro konecné produkty pokrocilé glykace (RAGE) - klícový hrác diabetické angiopatie?

Receptor for advanced glycation end-products plays a crucial role in chronic diabetes complications. It is supposed to be involved in the development of all kinds of diabetic angiopathy. Advanced glycation end-products (AGEs) excessively accumulated in diabetes belong to the most important ligands of RAGE, however there are more potent activators of this receptor - especially alarmins, often involved in inflammatory reactions. Activated RAGE triggers pathways leading to excessive accumulation of AGEs, reactive oxygen species and sustained inflammatory reactions via NF-κB. Central role of RAGE in the pathogenesis of vascular changes in diabetes represents suitable target for new therapeutic or preventive approach.Key words: advanced glycation end-products - diabetes mellitus - hyperglycaemia - macroangiopathy - methylglyoxal - microangiopathy - receptor for advanced glycation end-products.

Placental growth factor, pregnancy-associated plasma protein-A, soluble receptor for advanced glycation end products, extracellular newly identified receptor for receptor for advanced glycation end products binding protein and high mobility group box 1 levels in patients with acute kidney injury: a cross sectional study.

BACKGROUND: Placental growth factor (PlGF), pregnancy-associated plasma protein-A (PAPP-A), soluble receptor for advanced glycation end products (sRAGE), extracellular newly identified receptor for RAGE binding protein (EN-RAGE) and high mobility group box 1 (HMGB-1) are novel biomarkers in chronic kidney disease (CKD). However, their clinical significance in acute kidney injury (AKI) is unknown. The aim of this cross-sectional study was to determine whether selected biomarkers are changed in AKI patients. METHODS: Serum PlGF, PAPP-A, sRAGE, EN-RAGE and HMGB-1 levels were assessed in 40 patients with AKI, 42 CKD 5 patients, 31 haemodialysis patients (HD) and 39 age-matched healthy controls. RESULTS: PAPP-A was elevated in AKI (20.6 ± 16.9 mIU/L) compared with controls (9.1 ± 2.3 mIU/L, p < 0.001). PlGF was not increased in AKI (11.7 ± 7.4 pg/mL) versus controls (8.5 ± 2.4 pg/mL, n.s.), as well as sRAGE was not elevated in AKI (2400 ± 1400 pg/mL) compared with controls (1760 ± 730 pg/mL, n.s), but was lower compared with CKD 5 (3200 ± 1500 pg/mL, p < 0.05); EN-RAGE was elevated in AKI 480 ± 450 ng/mL in comparison with controls (60 ± 62 ng/mL), CKD 5 (190 ± 120 ng/mL), and HD (120 ± 100 ng/mL), all p < 0.001. Similarly, HMGB-1 was increased in AKI (5.8 ± 7.5 ng/mL) versus controls (1.7 ± 1.4 ng/mL), CKD 5 (3.2 ± 3.1 ng/mL) and HD (2.5 ± 2.1 ng/mL), all p < 0.001.In AKI group, in multivariate regression analysis: PAPP-A levels were associated with transferrin (p <0.001), negatively with albumin (p < 0.01) and prealbumin (p < 0.05); PlGF levels were associated with C--reactive protein (p < 0.001). EN-RAGE levels were associated with ferritin (p < 0.01) and orosomucoid (p = 0.02), and HMGB-1 levels with leukocyte count (p < 0.01) and negatively with proteinuria (p = 0.02). CONCLUSIONS: In AKI patients, PAPP-A, EN-RAGE and HMGB1 are elevated, but sRAGE and PlGF are not increased. Whereas PAPP-A correlates with markers of nutrition; PlGF, EN-RAGE and HMGB-1 are related to inflammatory parameters.