Advanced Glycation End-Products (AGEs) and Their Soluble Receptor (sRAGE) in Women Suffering from Systemic Lupus Erythematosus (SLE).

Systemic lupus erythematosus (SLE) is characterized by abnormal action of the immune system and a state of chronic inflammation. The disease can cause life-threatening complications. Neoepitopes arising from interdependent glycation and oxidation processes might be an element of SLE pathology. The groups included in the study were 31 female SLE patients and 26 healthy female volunteers (the control group). Blood serum samples were obtained to evaluate concentrations of advanced glycation end-products (AGEs), carboxymethyllysine (CML), carboxyethyllysine (CEL), pentosidine, and a soluble form of the receptor for advanced glycation end-products (sRAGE). Compared to a healthy control group, the SLE patients exhibited a higher concentration of AGEs and a lower concentration of sRAGE in serum. There were no statistically significant differences in serum CML, CEL, and pentosidine concentrations between the groups. Therefore, SLE patients could be at risk of intensified glycation process and activation of the proinflammatory receptor for advanced glycation end-products (RAGE), which could potentially worsen the disease course; however, it is not clear which compounds contribute to the increased concentration of AGEs in the blood. Additionally, information about the cigarette smoking and alcohol consumption of the study participants was obtained.

Extending the HSA-Cys34-Adductomics Pipeline to Modifications at Lys525.

We previously developed an adductomics pipeline that employed nanoflow liquid chromatography and high-resolution tandem mass spectrometry (nLC-HR-MS/MS) plus informatics to perform an untargeted detection of modifications to Cys34 in the tryptic T3 peptide of human serum albumin (HSA) (21ALVLIAFAQYLQQC34PFEDHVK41). In order to detect these peptide modifications without targeting specific masses, the pipeline interrogates MS2 ions that are signatures of the T3 peptide. The pipeline had been pilot-tested with archived plasma from healthy human subjects, and several of the 43 Cys34 adducts were highly associated with the smoking status. In the current investigation, we adapted the pipeline to include modifications to the ε-amino group of Lys525─a major glycation site in HSA─and thereby extend the coverage to products of Schiff bases that cannot be produced at Cys34. Because trypsin is generally unable to digest proteins at modified lysines, our pipeline detects miscleaved tryptic peptides with the sequence 525KQTALVELVK534. Adducts of both Lys525 and Cys34 are measured in a single nLC-HR-MS/MS run by increasing the mass range of precursor ions in MS1 scans and including both triply and doubly charged precursor ions for collision-induced dissociation fragmentation. For proof of principle, we applied the Cys34/Lys525 pipeline to archived plasma specimens from a subset of the same volunteer subjects used in the original investigation. Twelve modified Lys525 peptides were detected, including products of glycation (fructosyl-lysine plus advanced-glycated-end products), acetylation, and elimination of ammonia and water. Surprisingly, the carbamylated and glycated adducts were present at significantly lower levels in smoking subjects. By including a larger class of in vivo nucleophilic substitution reactions, the Cys34/Lys525 adductomics pipeline expands exposomic investigations of unknown human exposure to reactive electrophiles derived from both exogenous and endogenous sources.

Urinary excretion of amino acids and their advanced glycation end-products (AGEs) in adult kidney transplant recipients with emphasis on lysine: furosine excretion is associated with cardiovascular and all-cause mortality.

Arginine (Arg) and lysine (Lys) moieties of proteins undergo various post-translational modifications (PTM) including enzymatic NG- and Nε-methylation and non-enzymatic NG- and Nε-glycation. In a large cohort of stable kidney transplant recipients (KTR, n = 686), high plasma and low urinary concentrations of asymmetric dimethylarginine (ADMA), an abundant PTM metabolite of Arg, were associated with cardiovascular and all-cause mortality. Thus, the prediction of the same biomarker regarding mortality may depend on the biological sample. In another large cohort of stable KTR (n = 555), higher plasma concentrations of Nε-carboxymethyl-lysine (CML) and Nε-carboxyethyl-lysine (CEL), two advanced glycation end-products (AGEs) of Lys, were associated with higher cardiovascular mortality. Yet, the associations of urinary AGEs with mortality are unknown. In the present study, we measured 24 h urinary excretion of Lys, CML, and furosine in 630 KTR and 41 healthy kidney donors before and after donation. Our result indicate that lower urinary CML and lower furosine excretion rates are associated with higher mortality in KTR, thus resembling the associations of ADMA. Lower furosine excretion rates were also associated with higher cardiovascular mortality. The 24 h urinary excretion rate of amino acids and their metabolites decreased post-donation (varying as little as - 24% for CEL, and as much as - 62% for ADMA). For most amino acids, the excretion rate was lower in KTR than in donors pre-donation [except for S-(1-carboxyethyl)-L-cysteine (CEC) and NG-carboxyethylarginine (CEA)]. Simultaneous GC-MS measurement of free amino acids, their PTM metabolites and AGEs in urine is a non-invasive approach in kidney transplantation.

Oncogenic and tumor suppressor pathways in subchronic aflatoxicosis in rats: Association with serum and urinary aflatoxin exposure biomarkers.

In this study, the changes in oncogenic and tumor suppressor signaling pathways in liver and their association with serum and urinary biomarkers of aflatoxin exposure were evaluated in Wistar rats fed diets containing aflatoxin B1 (AFB1) for 90 days. Rats were divided into four groups (n = 15 per group) and assigned to dietary treatments containing 0 (control), 50 (AFB50), 100 (AFB100) and 200 µg AFB1 kg-1 diet (AFB200). Multiple preneoplastic foci of hepatocytes marked with glutathione-S-transferase-placental form (GST-P) were identified in AFB100 and AFB200 groups. Hepatocellular damage induced by AFB1 resulted in overexpression of cyclin D1 and ß-catenin. The liver expression of retinoblastoma (Rb) and p27Kip1 decreased in AFB100 and AFB200 groups, confirming the favorable conditions for neoplastic progression to hepatocellular carcinoma. All samples from rats fed AFB1-contaminated diets had quantifiable AFB1-lysine in serum or urinary AFM1 and AFB1-N7-guanine, with mean levels of 20.42-50.34 ng mL-1, 5.31-37.68 and 39.15-126.37 ng mg-1 creatinine, respectively. Positive correlations were found between AFB1-lysine, AFM1 or AFB1-N7-guanine and GST-P+, ß-catenin+ and cyclin D1+ hepatocytes, while Rb + cells negatively correlated with those AFB1 exposure biomarkers. The pathways evaluated are critical molecular mechanisms of AFB1-induced hepatocarcinogenesis in rats.

Triangulating evidence from longitudinal and Mendelian randomization studies of metabolomic biomarkers for type 2 diabetes.

The number of people affected by Type 2 diabetes mellitus (T2DM) is close to half a billion and is on a sharp rise, representing a major and growing public health burden. Given its mild initial symptoms, T2DM is often diagnosed several years after its onset, leaving half of diabetic individuals undiagnosed. While several classical clinical and genetic biomarkers have been identified, improving early diagnosis by exploring other kinds of omics data remains crucial. In this study, we have combined longitudinal data from two population-based cohorts CoLaus and DESIR (comprising in total 493 incident cases vs. 1360 controls) to identify new or confirm previously implicated metabolomic biomarkers predicting T2DM incidence more than 5 years ahead of clinical diagnosis. Our longitudinal data have shown robust evidence for valine, leucine, carnitine and glutamic acid being predictive of future conversion to T2DM. We confirmed the causality of such association for leucine by 2-sample Mendelian randomisation (MR) based on independent data. Our MR approach further identified new metabolites potentially playing a causal role on T2D, including betaine, lysine and mannose. Interestingly, for valine and leucine a strong reverse causal effect was detected, indicating that the genetic predisposition to T2DM may trigger early changes of these metabolites, which appear well-before any clinical symptoms. In addition, our study revealed a reverse causal effect of metabolites such as glutamic acid and alanine. Collectively, these findings indicate that molecular traits linked to the genetic basis of T2DM may be particularly promising early biomarkers.

Plasma concentrations of advanced glycation end-products and colorectal cancer risk in the EPIC study.

Advanced glycation end-products (AGEs) are a heterogeneous group of compounds formed by the non-enzymatic reaction between amino acids and reducing sugars, or dicarbonyls as intermediate compounds. Experimental studies suggest that AGEs may promote colorectal cancer, but prospective epidemiologic studies are inconclusive. We conducted a case-control study nested within a large European cohort. Plasma concentrations of three protein-bound AGEs-Nε-(carboxy-methyl)lysine (CML), Nε-(carboxy-ethyl)lysine (CEL) and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1)-were measured by ultra-performance liquid chromatography-tandem mass spectrometry in baseline samples collected from 1378 incident primary colorectal cancer cases and 1378 matched controls. Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were computed using conditional logistic regression for colorectal cancer risk associated with CML, CEL, MG-H1, total AGEs, and [CEL+MG-H1: CML] and [CEL:MG-H1] ratios. Inverse colorectal cancer risk associations were observed for CML (OR comparing highest to lowest quintile, ORQ5 versus Q1 = 0.40, 95% CI: 0.27-0.59), MG-H1 (ORQ5 versus Q1 = 0.73, 95% CI: 0.53-1.00) and total AGEs (OR Q5 versus Q1 = 0.52, 95% CI: 0.37-0.73), whereas no association was observed for CEL. A higher [CEL+MG-H1: CML] ratio was associated with colorectal cancer risk (ORQ5 versus Q1 = 1.91, 95% CI: 1.31-2.79). The associations observed did not differ by sex, or by tumour anatomical sub-site. Although individual AGEs concentrations appear to be inversely associated with colorectal cancer risk, a higher ratio of methylglyoxal-derived AGEs versus those derived from glyoxal (calculated by [CEL+MG-H1: CML] ratio) showed a strong positive risk association. Further insight on the metabolism of AGEs and their dicarbonyls precursors, and their roles in colorectal cancer development is needed.

Plasma pharmacokinetics and tissue distribution of L-lysine α-oxidase from Trichoderma cf. aureoviride RIFAI VKM F- 4268D in mice.

L-lysine α-oxidase (LO) is an L-amino acid oxidase with antitumor, antimicrobial and antiviral properties. Pharmacokinetic (PK) studies were carried out by measuring LO concentration in plasma and tissue samples by enzyme immunoassay. L-lysine concentration in samples was measured spectrophotometrically using LO. After single i.v. injection of 1.0, 1.5, 3.0 mg/kg the circulating T1/2 of enzyme in mice varied from 51 to 74 min and the AUC0-inf values were 6.54 ± 0.46, 8.66 ± 0.59, 9.47 ± 1.45 µg/ml × h, respectively. LO was distributed in tissues and determined within 48 h after administration with maximal accumulation in liver and heart tissues. Mean time to reach the maximum concentration was highest for the liver-9 h, kidney-1 h and 15 min for the tissues of heart, spleen and brain. T1/2 of LO in tissues ranged from 7.75 ± 0.73 to 26.10 ± 2.60 h. In mice, plasma L-lysine decreased by 79% 15 min after LO administration in dose 1.6 mg/kg. The serum L-lysine levels remained very low from 1 to 9 h (< 25 µM, 17%), indicating an acute lack of L-lysine in animals for at least 9 h. Concentration of L-lysine in serum restored only 24 h after LO administration. The results of LO PK study show that it might be considered as a promising enzyme for further investigation as a potential anticancer agent.

Comprehensive Quantification of Carboxymethyllysine-Modified Peptides in Human Plasma.

A prolonged hyperglycemic condition in diabetes mellitus results in glycation of plasma proteins. N(ε)-Carboxymethyllysine (CML) is a well-known protein advanced glycation end product, and one of its mechanisms of formation is through further oxidation of Amadori compound modified lysine (AML). Unlike enrichment of AML peptides using boronate affinity, biochemical enrichment methods are scarce for comprehensive profiling of CML-modified peptides. To address this problem, we used AML peptide sequence and site of modification as template library to identify and quantify CML peptides. In this study, a parallel reaction monitoring workflow was developed to comprehensively quantify CML modified peptides in Type 1 diabetic subjects' plasma with good and poor glycemic control (n = 20 each). A total of 58 CML modified peptides were quantified, which represented 57 CML modification sites in 19 different proteins. Out of the 58 peptides, five were significantly higher in poor glycemic control samples with the area under the receiver operating characteristic curve ≥0.83. These peptides could serve as promising indicators of glycemic control in Type 1 diabetes management.

Enrichment of apolipoprotein A-IV and apolipoprotein D in the HDL proteome is associated with HDL functions in diabetic kidney disease without dialysis.

BACKGROUND AND AIMS: Diabetic kidney disease (DKD) is associated with lipid derangements that worsen kidney function and enhance cardiovascular (CVD) risk. The management of dyslipidemia, hypertension and other traditional risk factors does not completely prevent CVD complications, bringing up the participation of nontraditional risk factors such as advanced glycation end products (AGEs), carbamoylation and changes in the HDL proteome and functionality. The HDL composition, proteome, chemical modification and functionality were analyzed in nondialysis subjects with DKD categorized according to the estimated glomerular filtration rate (eGFR) and urinary albumin excretion rate (AER). METHODS: Individuals with DKD were divided into eGFR> 60 mL/min/1.73 m2 plus AER stages A1 and A2 (n = 10) and eGFR< 60 plus A3 (n = 25) and matched by age with control subjects (eGFR> 60; n = 8). RESULTS: Targeted proteomic analyses quantified 28 proteins associated with HDL in all groups, although only 2 were more highly expressed in the eGFR< 60 + A3 group than in the controls: apolipoprotein D (apoD) and apoA-IV. HDL from the eGFR< 60 + A3 group presented higher levels of total AGEs (20%), pentosidine (6.3%) and carbamoylation (4.2 x) and a reduced ability to remove 14C-cholesterol from macrophages (33%) in comparison to HDL from controls. The antioxidant role of HDL (lag time for LDL oxidation) was similar among groups, but HDL from the eGFR< 60 + A3 group presented a greater ability to inhibit the secretion of IL-6 and TNF-alpha (95%) in LPS-elicited macrophages in comparison to the control group. CONCLUSION: The increase in apoD and apoA-IV could contribute to counteracting the HDL chemical modification by AGEs and carbamoylation, which contributes to HDL loss of function in well-established DKD.

Evaluation of oxidative stress effects on different macromolecules in adult growth hormone deficiency.

Adult growth hormone deficiency (GHD) is being increasingly recognized to cause premature mortality exacerbated by oxidative stress. A case-control observational study has been performed with the primary objective of evaluating new parameters of oxidative stress and macromolecular damage in adult GHD subjects: serum nitrotryptophan; Total Antioxidant Capacity expressed as LAG time; urinary hexanoil-lysine; urinary dityrosine and urinary 8-OH-deoxyguanosine. GHD was diagnosed using Growth Hormone-Releasing Hormone 50µg iv+arginine 0,5 g/Kg test, with a peak GH response <9 µg /L when BMI was <30 kg/m2 or <4 µg/L when BMI was >30 kg/m2. Patients affected by adult GHD were divided into three groups, total GHD (n = 26), partial GHD (n = 25), and controls (n = 29). Total Antioxidant Capacity, metabolic and hormonal parameters have been determined in separate plasma samples; nitrotryptophan in serum samples; hexanoil-lysine, dityrosine, 8-OH-deoxyguanosine in urine samples. Assessment of hexanoil-lysine exhibited a trend to increase in comparing total GHD vs partial and controls, although not significant. Values of 8-OH-deoxyguanosine did not significantly differ among the three groups. Significant lower levels of dityrosine in partial GHD vs total and controls were found. No significant difference in nitrotriptophan serum levels was found, while significantly greater values of Total Antioxidant Capacity were showed in total and partial GHD vs controls. Thus, our result confirm that oxidative stress is increased both in partial and total adult GHD. The lack of compensation by antioxidants in total GHD may be connected to the complications associated to this rare disorder.

Clinical and biochemical characteristics of patients with ornithine transcarbamylase deficiency.

BACKGROUND: Ornithine transcarbamylase deficiency (OTCD) is pleomorphic congenital hyperammonemia, in which the prognosis of the patient is determined both by genotype and environmental factors. This study investigated the clinical and biochemical characteristics of OTCD patients with different prognosis. METHOD: Of 35 OTCD patients, six males deceased at the first disease-onset, 17 males survived and had controllable ammonia levels after treatment, and 12 females survived through the first disease-onset but had intractable hyperammonemia and high mortality. Fasting blood samples from patients collected at three disease stages were used for the analysis of amino acid (AA) profile, acylcarnitine profile, and micronutrients. Differences in profiles between patients and healthy controls and within patient groups were studied. RESULTS: All OTCD patients had accumulation of glutamine, homocitrulline, lysine, glutamate, cystathionine, and pipecolic acid, as well as deficiency of citrulline, tryptophan, threonine, and carnitine. For male non-survivors, most other AAs and long-chain acylcarnitines were elevated at disease onset, of which the levels of creatine, N-acetylaspartic acid, and homoarginine were remarkably high. Male survivors and female patients had most other AAs at low to normal levels. Compared with male survivors, female patients had much lower protein-intolerance, as indicated by significantly lower levels of protein consumption indicators, including essential AAs, 1-methylhistidine, acylcarnitines et al., but high levels of ammonia. Female patients still had significantly higher levels of citrulline, homocitrulline, and citrulline/arginine compared to male survivors. CONCLUSION: Unique profiles were observed in each group of OTCD patients, indicating specific physiological changes that happened to them.

Dietary quality index is negatively associated with serum advanced glycation end products in healthy adults.

BACKGROUND AND AIMS: In human, advanced glycation end products (AGEs) can endogenously formed or exogenously ingested from foods and tobacco. Dietary quality is an important factor to prevent many disorders. This study sought to determine any association between AGEs and diet quality. METHODS: The participants were 90 healthy adults, aged higher than 20 years. Dietary intake of individuals was collected using two 24-h dietary recalls and quality of diets were determined by dietary quality index-International (DQI-I). Serum levels of pentosidine and carboxymethyl-lysine (CML) were examined by ELISA. RESULTS: Total DQI-I score was 62.3 ± 1.3. Variety, adequacy, moderation, and the overall balance of diet scores in the study participants were 16.5 ± 0.4, 25.8 ± 0.5, 17.7 ± 0.9, and 2.4 ± 0.3, respectively. Participants with higher age (>40 years), higher education level, moderate calorie intake and married had significantly greater DQI-I score. Diet quality was positively associated with participants' education level (r = 0.28, p = 0.008). DQI-I score negatively correlated with serum levels of CML and pentosidine (r = -0.42, P < 0.001 and r = -0.35, P < 0.001, respectively). CONCLUSION: Dietary modification may be beneficial for controlling AGE accumulation in the body and subsequently in reduction of chronic diseases risk.

Metabolomics analysis identifies lysine and taurine as candidate prognostic biomarkers for AML-M2 patients.

There is an ongoing search for potential biomarkers for acute myeloid leukemia (AML) patients using metabolic analysis. However, only few studies to date have focused on bone marrow samples or a specific subtype of AML. In the present study, we used gas chromatography time-of-flight mass spectrometry of plasma and bone marrow supernatants to compare the metabolic characteristics of patients with AML with maturation (AML-M2). This approach identified significantly altered metabolites. We next performed pathway analysis and determined relative mRNA expression by qRT-PCR. Our results show that lysine, methionine and serine were significantly decreased in AML-M2 patients compared with healthy control. Moreover, plasma abundance of lysine was negatively associated with patients' risk stratification. Taurine had higher plasma abundance in AML-M2 patients and plasma level of taurine was positively related with AML-M2 risk status, while the expression level of taurine transporter showed a negative correlation. Receiver operating characteristic curve analysis showed these four metabolites had high diagnostic value with lysine showing the highest sensitivity and specificity. These results suggest that plasma abundances of lysine and taurine may serve as potential metabolic biomarkers for the prognosis of patients with AML-M2.

Identification of Differential Patterns of Oxidative Biomarkers in Prostate Cancer Progression.

INTRODUCTION: Oxidative stress has been found to be associated with the progression of prostate cancer (PCa); however, human studies which identify differential roles of each oxidation pathway in PCa progression are lacking. We aimed to identify which oxidative stress markers, specifically lipid and global oxidation and glycation, are associated with PCa progression. PATIENTS AND METHODS: We recruited 3 groups of patients from a urologic clinic at the University of Cincinnati Medical Center: men with PCa who had undergone prostatectomy, men with PCa under watchful waiting, and men with benign prostatic hyperplasia (BPH). We used the most commonly used lipid oxidation marker, F2-isoprostanes; global oxidation markers, fluorescent oxidation products (FlOPs); and the commonly used marker for advanced glycation end products, carboxymethyllysine. These biomarkers were measured in plasma samples at baseline entry. Plasma prostate-specific antigen (PSA) was measured at enrollment and follow-up visits. RESULTS: Compared with men with BPH, men with PCa who had undergone prostatectomy had 26% (P = .01) higher levels of F2-isoprostanes and 20% (P = .08) higher levels of carboxymethyllysine. All the oxidation markers were similar when comparing men under watchful waiting with men with BPH. When examining the associations between baseline oxidation markers and follow-up PSAs, we found that different oxidation markers had differential patterns associated with PSA elevation. F2-isoprostanes were positively associated with PSA elevation among men with PCa; FlOP_320 was positively associated with PSA elevation among both men with PCa and men with BPH, whereas among men with PCa under watchful waiting, FlOP_360 and FlOP_400 had opposite trends of associations with PSA elevation. CONCLUSIONS: Our study suggested that high levels of lipid oxidation were associated with PCa progression, whereas different global oxidation markers had different patterns associated with PCa progression. Large-scale clinical studies are needed to confirm our associations. Our study provides a comprehensive view of the relationship between biomarkers and PCa progression.

Dietary and Plasma Carboxymethyl Lysine and Tumor Necrosis Factor-α as Mediators of Body Mass Index and Waist Circumference among Women in Indonesia.

Dietary and plasma carboxymethyl lysine (dCML, pCML) and plasma tumor necrosis factor-α (pTNF-α) may be associated with obesity in affluent society. However, evidence in women from low-middle income countries with predominantly traditional diets is lacking. We investigated the mediator effects of dCML, pCML and pTNF-α on body mass index (BMI) and waist circumference (WC) among Indonesian women. A cross-sectional study was conducted among 235 non-diabetic, non-anemic and non-smoking women aged 19-50 years from selected mountainous and coastal areas of West Sumatra and West Java. Dietary CML, pCML, pTNF-α were obtained from 2 × 24-h recalls, ultra-performance liquid chromatography-tandem mass spectrometry and enzyme-linked immunosorbent assay, respectively. Between-group differences were analyzed by the Chi-square or Mann-Whitney test and mediator effects by Structural Equation Modeling. The medians and interquartile-ranges of dCML, pCML and pTNF-α were 2.2 (1.7-3.0) mg/day, 22.2 (17.2-28.2) ng/mL and 0.68 (0.52-1.00) IU/mL, respectively, and significantly higher in the WC ≥ 80 cm than in the WC < 80 cm group, but not in BMI ≥ 25 kg/m2 compared to BMI < 25 kg/m2 group. Plasma CML and pTNF-α were positively and directly related to WC (ß = 0.21 [95% CI: 0.09, 0.33] and ß = 0.23 [95% CI: 0.11, 0.35], respectively). Dietary CML that correlated with dry-heat processing and cereals as the highest contributions was positively related to WC (ß = 0.33 [95% CI: 0.12, 0.83]). Ethnicity, level of education, intake of fat, and intake of energy contributed to dCML, pCML and pTNF-α, and subsequently affected WC, while only ethnicity contributed to BMI through dCML, pCML and pTNF-α (ß = 0.07 [95% CI: 0.01, 0.14]). A positive direct effect of dCML on pCML and of pCML and pTNF-α on WC was seen among Indonesian women. Dietary CML seems to have several paths that indirectly influence the increases in WC if compared to BMI. Thus, intake of CML-rich foods should be reduced, or the foods consumed in moderate amounts to avoid the risk of central obesity in this population.

Characteristics of amino acid profiles and incretin hormones in patients with gallstone disease: a pilot study.

INTRODUCTION: Gallstone disease is associated with insulin resistance, type 2 diabetes mellitus, and increased risk of incident ischemic heart disease. It is known that the profile of branched­chain amino acids (BCAAs) is altered in cardiac diseases as well as metabolic diseases, such as diabetes and obesity. The role of BCAAs in gallstone disease is still not known. OBJECTIVES: The aim of this study was to evaluate the concentration of essential amino acids and incretin hormones in patients with cholecystolithiasis. PATIENTS AND METHODS: The study included 31 patients with cholecystolithiasis and 25 gallstone­free controls. The levels of free exogenous and endogenous amino acids, bile acids, glucagon­like peptide 1, glucose­dependent insulinotropic polypeptide, ghrelin, C-peptide, and insulin were measured in the fasting state and 1 hour after consumption of a 300­kcal mixed meal. RESULTS: The mean fasting and postprandial levels of valine, isoleucine, leucine, and lysine were higher in the study group than in controls (all P.

Systemic translation of locally infiltrated epidermal growth factor in diabetic lower extremity wounds.

Diabetic foot ulcer is one of the most frightened diabetic complications leading to amputation disability and early mortality. Diabetic wounds exhibit a complex networking of inflammatory cytokines, local proteases, and reactive oxygen and nitrogen species as a pathogenic polymicrobial biofilm, overall contributing to wound chronification and host homeostasis imbalance. Intralesional infiltration of epidermal growth factor (EGF) has emerged as a therapeutic alternative to diabetic wound healing, reaching responsive cells while avoiding the deleterious effect of proteases and the biofilm on the wound's surface. The present study shows that intralesional therapy with EGF is associated with the systemic attenuation of pro-inflammatory markers along with redox balance recovery. A total of 11 diabetic patients with neuropathic foot ulcers were studied before and 3 weeks after starting EGF treatment. Evaluations comprised plasma levels of pro-inflammatory, redox balance, and glycation markers. Pro-inflammatory markers such as erythrosedimentation rate, C-reactive protein, interleukin-6, soluble FAS, and macrophage inflammatory protein 1-alpha were significantly reduced by EGF therapy. Oxidative capacity, nitrite/nitrate ratio, and pentosidine were also reduced, while soluble receptor for advanced glycation end-products significantly increased. Overall, our results indicate that the local intralesional infiltration of EGF translates in systemic anti-inflammatory and antioxidant effects, as in attenuation of the glycation products' negative effects.

Pro-oxidant and pro-inflammatory effects of glycated albumin on cardiomyocytes.

Human serum albumin (HSA) is the most abundant circulating protein in the body and presents an extensive range of biological functions. As such, it is prone to undergo post-translational modifications (PTMs). The non-enzymatic early glycation of HSA, one of the several PTMs undergone by HSA, arises from the addition of reducing sugars to amine group residues, thus modifying the structure of HSA. These changes may affect HSA functions impairing its biological activity, finally leading to cell damage. The aim of this study was to quantitate glycated-HSA (GA) levels in the plasma of heart failure (HF) patients and to evaluate the biological effects of GA on HL-1 cardiomyocytes. Plasma GA content from HF patients and healthy subjects was measured by direct infusion electrospray ionization mass spectrometry (ESI-MS). Results pointed out a significant increase of GA in HF patients with respect to the control group (p < 0.05). Additionally, after stimulation with GA, proteomic analysis of HL-1 secreted proteins showed the modulation of several proteins involved, among other processes, in the response to stress. Further, stimulated cells showed a rapid increase in ROS generation, higher mRNA levels of the inflammatory cytokine interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), and higher levels of the oxidative 4-HNE-protein adducts and carbonylated proteins. Our findings show that plasma GA is increased in HF patients. Further, GA exerts pro-inflammatory and pro-oxidant effects on cardiomyocytes, which suggest a causal role in the etiopathogenesis of HF.

Study of aflatoxicosis reduction: effect of Alchornea cordifolia on biomarkers in an aflatoxin B1 exposed rats.

The toxicity of aflatoxins results in cancer and liver disease. Several natural substances such as plants exhibited their ability to inhibit the initiation of aflatoxin carcinogenesis. The aim of this study was to evaluate the effect of Alchornea cordifolia on biomarkers in an aflatoxin B1 (AFB1) exposed rats. The contents of polyphenols, flavonoids and the antioxidant activity of A. cordifolia ethanolic leaf extract (EELac) were assessed. Groups of rats were treated orally with a daily dose of a mixture of AFB1 at a dose of 150 µg/kg body weight and EELac (50, 100 and 300 mg/kg body weight) for 21 days. Biomarkers of AFB1, such as the AFB1-lysine adduct and aflatoxin M1 were assayed in blood and urine, respectively, using an HPLC system with a fluorescence detector. The contents of polyphenols and flavonoids were 6783.23 ± 272.76 µg EAG/g and 10.54 ± 3.15% of dry matter, respectively. EELac showed a good antioxidant activity (IC50 = 12.65 ± 0.13 µg/mL). The administration of the mixture (AFB1 + EELac) at different doses significantly reduced the level of AFB1-lysine adduct from 14.04 ± 2.1 to 4.13 ± 0.9 ng/mg albumin and that of Aflatoxin M1 (AFM1) from 456 ± 16 to 220 ± 24 ng/mL (p <0.05). The rate of reduction was 70.58% for AFB1-lysine adduct and 51.75% for AFM1. A. cordifolia could be used in the prevention of toxicity induced by AFB1 on account of its high content in phenolic compounds.

Investigation of hallmarks of carbonyl stress and formation of end products in feline chronic kidney disease as markers of uraemic toxins.

OBJECTIVES: Cats are commonly affected by chronic kidney disease (CKD). Many reactive carbonyl intermediates and end products originating from the oxidative stress pathways are recognised as uraemic toxins and may play a role in CKD progression. The aim of the present study is to confirm whether carbonyl end-product formation is higher in cats affected by CKD and to assess whether an angiotensin-converting enzyme inhibitor (ACEi) might affect these hallmarks. METHODS: Twenty-two cats were divided into three groups: a control group (CG), cats with CKD and cats with CKD treated with an ACEi. Serum levels of pentosidine, carboxymethyllysine, advanced oxidation protein products, malondialdehyde, methylglyoxal and hexanoyl-lysine were measured. In addition, biochemical parameters and systolic blood pressure were evaluated. After checking for normality, comparisons between groups were performed followed by multiple comparison tests. P values ⩽0.05 were considered significant. Correlations between concentrations of the considered biomarkers and of the other metabolic parameters were investigated. RESULTS: Advanced oxidation protein products, malondialdehyde and hexanoyl-lysine concentrations were significantly higher in CKD and ACEi-treated groups compared with the CG ( P <0.05). Carboxymethyllysine increased in the ACEi-treated group when compared with the CG, whereas intermediate values of these biomarkers were found in the CKD group ( P <0.05). The ACEi-treated group showed the highest values of carboxymethyllysine, advanced oxidation protein products and hexanoyl-lysine. By contrast, the CKD group had the highest concentration of malondialdehyde. No statistically significant difference was found in the levels of pentosidine or methylglyoxal. End products correlated with creatinine and urea and with each other. CONCLUSIONS AND RELEVANCE: Significantly high concentrations of both intermediate and end products of carbonyl/oxidative stress were detected in CKD cats. This is the first study to have concurrently taken into account several uraemic toxins and biochemical parameters in cats affected by CKD.