Diabetes and Colorectal Cancer Risk: Clinical and Therapeutic Implications.

Several epidemiological studies have identified diabetes as a risk factor for colorectal cancer (CRC). The potential pathophysiological mechanisms of this association include hyperinsulinemia, insulin-like growth factor (IGF) axis, hyperglycemia, inflammation induced by adipose tissue dysfunction, gastrointestinal motility disorder, and impaired immunological surveillance. Several studies have shown that underlying diabetes adversely affects the prognosis of patients with CRC. This review explores the novel anticancer agents targeting IGF-1R and receptor for advanced glycation end products (RAGE), both of which play a vital role in diabetes-induced colorectal tumorigenesis. Inhibitors of IGF-1R and RAGE are expected to become promising therapeutic choices, particularly for CRC patients with diabetes. Furthermore, hypoglycemic therapy is associated with the incidence of CRC. Selection of appropriate hypoglycemic agents, which can reduce the risk of CRC in diabetic patients, is an unmet issue. Therefore, this review mainly summarizes the current studies concerning the connections among diabetes, hypoglycemic therapy, and CRC as well as provides a synthesis of the underlying pathophysiological mechanisms. Our synthesis provides a theoretical basis for rational use of hypoglycemic therapies and early diagnosis and treatment of diabetes-related CRC.

sRAGE downregulates the VEGF expression in OHSS ovarian granulosa cells.

OBJECTIVE: Ovarian hyperstimulation syndrome (OHSS) is mainly caused by human chorionic gonadotropin (hCG) through vasoactive mediators such as vascular endothelial growth factor (VEGF) and various inflammatory factors. Our previous study showed that soluble receptor for advanced glycation end products (sRAGE) played a protective role in PCOS by inhibiting VEGF, so wanted to explore the role of sRAGE in OHSS. METHODS: Two sets of experiments were performed in this study. In part one, sRAGE protein levels in follicular fluid (FF) samples from 60 patients with OHSS and 60 non-OHSS patients were measured by ELISA. In part two, ovarian granulosa cells were isolated from an additional 25 patients with OHSS and cultured. Then, ovarian granulosa cells were treated with different concentrations of sRAGE. Granulosa cells cultured without sRAGE stimulation were used as the control group. The levels of VEGF, amphiregulin (AREG), betacellulin (BTC), and epiregulin (EREG) mRNA were examined by quantitative RT-PCR. The protein levels of VEGF, AREG, BTC, and EREG were measured by ELISA. RESULTS: Compared with non-OHSS patients, patients with OHSS exhibited lower sRAGE levels in both serum and FF (p < .05). Treatment with sRAGE decreased the production of VEGF, and the effects were dependent on the concentration of sRAGE (p < .05). Simultaneously, the expression of the EGF-like growth factors AREG, BTC and EREG was decreased, and their expression was dependent on the concentration of sRAGE (p < .05). CONCLUSIONS: sRAGE downregulate VEGF expression in OHSS ovarian granulosa cells, in which EGF-like growth factor pathway may be involved, and sRAGE may play a potential protective role in OHSS.

AGE/RAGE/DIAPH1 axis is associated with immunometabolic markers and risk of insulin resistance in subcutaneous but not omental adipose tissue in human obesity.

BACKGROUND/OBJECTIVES: The incidence of obesity continues to increase worldwide and while the underlying pathogenesis remains largely unknown, nutrient excess, manifested by "Westernization" of the diet and reduced physical activity have been proposed as key contributing factors. Western-style diets, in addition to higher caloric load, are characterized by excess of advanced glycation end products (AGEs), which have been linked to the pathophysiology of obesity and related cardiometabolic disorders. AGEs can be "trapped" in adipose tissue, even in the absence of diabetes, in part due to higher expression of the receptor for AGEs (RAGE) and/or decreased detoxification by the endogenous glyoxalase (GLO) system, where they may promote insulin resistance. It is unknown whether the expression levels of genes linked to the RAGE axis, including AGER (the gene encoding RAGE), Diaphanous 1 (DIAPH1), the cytoplasmic domain binding partner of RAGE that contributes to RAGE signaling, and GLO1 are differentially regulated by the degree of obesity and/or how these relate to inflammatory and adipocyte markers and their metabolic consequences. SUBJECTS/METHODS: We sought to answer this question by analyzing gene expression patterns of markers of the AGE/RAGE/DIAPH1 signaling axis in abdominal subcutaneous (SAT) and omental (OAT) adipose tissue from obese and morbidly obese subjects. RESULTS: In SAT, but not OAT, expression of AGER was significantly correlated with that of DIAPH1 (n = 16; [Formula: see text], [0.260, 1.177]; q = 0.008) and GLO1 (n = 16; [Formula: see text], [0.364, 1.182]; q = 0.004). Furthermore, in SAT, but not OAT, regression analyses revealed that the expression pattern of genes in the AGE/RAGE/DIAPH1 axis is strongly and positively associated with that of inflammatory and adipogenic markers. Remarkably, particularly in SAT, not OAT, the expression of AGER positively and significantly correlated with HOMA-IR (n = 14; [Formula: see text], [0.338, 1.249]; q = 0.018). CONCLUSIONS: These observations suggest associations of the AGE/RAGE/DIAPH1 axis in the immunometabolic pathophysiology of obesity and insulin resistance, driven, at least in part, through expression and activity of this axis in SAT.

Pathological Role of Receptor for Advanced Glycation End Products in Calcified Aortic Valve Stenosis.

Background Aortic stenosis (AS) is highly prevalent in patients with atherosclerotic cardiovascular disease. Advanced glycation end products (AGEs) and the receptor for AGEs (RAGE) play a pivotal role for vascular calcification in atherosclerosis. We hypothesize that the AGEs-RAGE axis could also be involved in the pathophysiological mechanism of calcified AS. Methods and Results A total of 54 patients with calcified AS who underwent aortic valve replacement were prospectively enrolled from 2014 to 2016 (mean age 75.3±7.7 years). Aortic valve specimens were obtained from 47 patients and 16 deceased control subjects without aortic valve disease (mean age 63.2±14.5 years). The valvular expression of RAGE was evaluated by immunohistochemistry. Serum levels of AGEs and soluble RAGE were measured in 50 patients with calcified AS and 70 age-matched and sex-matched control subjects without heart disease. The valvular RAGE expression in patients with calcified AS was higher than controls (P=0.004) and was significantly associated with a decreased ankle-brachial pressure index (P=0.007) and an increased intima-media thickness (P=0.026). RAGE and α-smooth muscle actin were coexpressed and were partially costained with osteocalcin and alkaline phosphatase. The serum levels of AGEs and soluble RAGE were significantly higher in the patients with calcified AS than in the controls (P=0.013 and P<0.001, respectively). Soluble RAGE (inversely) and use of aspirin were independently correlated with changes in left ventricular systolic function after aortic valve replacement (P=0.012 and P=0.002, respectively). Conclusions Our present study suggests that RAGE may play a role in the pathogenesis of calcified AS, which is a prognostic marker in patients with AS after aortic valve replacement.

Radiolabeling of [11C]FPS-ZM1, a receptor for advanced glycation end products-targeting positron emission tomography radiotracer, using a [11C]CO2-to-[11C]CO chemical conversion.

Aim: The receptor for advanced glycation end products (RAGE) is a viable target for early Alzheimer's disease (AD) diagnosis using positron emission tomography (PET) as RAGE overexpression precedes Aß plaque formation. The development of a carbon-11 analog of FPS-ZM1 (N-benzyl-4-chloro-N-cyclohexylbenzamide, [11C]FPS-ZM1), possessing nanomolar affinity for RAGE, may enable the imaging of RAGE for early AD detection. Methodology & results: Herein we report an optimized [11C]CO2-to-[11C]CO chemical conversion for the synthesis of [11C]FPS-ZM1 and in vitro brain autoradiography. The [11C]CO2-to-[11C]CO conversion via 11C-silanecarboxylate derivatives was achieved with a 57% yield within 30 s from end of [11C]CO2 delivery. [11C]FPS-ZM1 was obtained with a decay-corrected isolated radiochemical yield of 9.5%. Conclusion: [11C]FPS-ZM1 distribution in brain tissues of wild-type versus transgenic AD model mice showed no statistically significant difference and high nondisplaceable binding.

Necrosis Rather Than Apoptosis is the Dominant form of Alveolar Epithelial Cell Death in Lipopolysaccharide-Induced Experimental Acute Respiratory Distress Syndrome Model.

Alveolar epithelial cell (AEC) death, which is classified as apoptosis or necrosis, plays a critical role in the pathogenesis of acute respiratory distress syndrome (ARDS). In addition to apoptosis, some types of necrosis are known to be molecularly regulated, and both apoptosis and necrosis can be therapeutic targets for diseases. However, the relative contribution of apoptosis and necrosis to AEC death during ARDS has not been elucidated. Here, we evaluated which type of AEC death is dominant and whether regulated necrosis is involved in lipopolysaccharide (LPS)-induced lung injury, an experimental ARDS model. In the bronchoalveolar lavage fluid from the LPS-induced lung injury mice, both the levels of cytokeratin 18-M65 antigen (a marker of total epithelial cell death) and cytokeratin 18-M30 antigen (an epithelial apoptosis marker) were increased. The M30/M65 ratio, which is an indicator of the proportion of apoptosis to total epithelial cell death, was significantly lower than that in healthy controls. In addition, the number of propidium iodide-positive, membrane-disrupted cells was significantly higher than the number of TUNEL-positive apoptotic cells in the lung sections of lung injury mice. Activated neutrophils seemed to mediate AEC death. Finally, we demonstrated that necroptosis, a regulated necrosis pathway, is involved in AEC death during LPS-induced lung injury. These results indicate that necrosis including necroptosis, rather than apoptosis, is the dominant type of AEC death in LPS-induced lung injury. Although further studies investigating human ARDS subjects are necessary, targeting necrosis including its regulated forms might represent a more efficient approach to protecting the alveolar epithelial barrier during ARDS.

Unique patterns of lower respiratory tract microbiota are associated with inflammation and hospital mortality in acute respiratory distress syndrome.

BACKGROUND: The lung microbiome maintains the homeostasis of the immune system within the lungs. In acute respiratory distress syndrome (ARDS), the lung microbiome is enriched with gut-derived bacteria; however, the specific microbiome associated with morbidity and mortality in patients with ARDS remains unclear. This study investigated the specific patterns of the lung microbiome that are correlated with mortality in ARDS patients. METHODS: We analyzed the lung microbiome from the bronchoalveolar lavage fluid (BALF) of patients with ARDS and control subjects. We measured the copy numbers of 16S rRNA and the serum and BALF cytokines (interleukin [IL]-6, IL-8, receptor for advanced glycation end products, and angiopoietin-2). RESULTS: We analyzed 47 mechanically ventilated patients diagnosed with (n = 40) or without (n = 7; control) ARDS. The alpha diversity was significantly decreased in ARDS patients compared with that of the controls (6.24 vs. 8.07, P = 0.03). The 16S rRNA gene copy numbers tended to be increased in the ARDS group compared with the controls (3.83 × 106 vs. 1.01 × 105 copies/mL, P = 0.06). ARDS patients were subdivided into the hospital survivor (n = 24) and non-survivor groups (n = 16). Serum IL-6 levels were significantly higher in the non-survivors than in the survivors (567 vs. 214 pg/mL, P = 0.027). The 16S rRNA copy number was significantly correlated with serum IL-6 levels in non-survivors (r = 0.615, P < 0.05). The copy numbers and relative abundance of betaproteobacteria were significantly lower in the non-survivors than in the survivors (713 vs. 7812, P = 0.012; 1.22% vs. 0.08%, P = 0.02, respectively). Conversely, the copy numbers of Staphylococcus, Streptococcus and Enterobacteriaceae were significantly correlated with serum IL-6 levels in the non-survivors (r = 0.579, P < 0.05; r = 0.604, P < 0.05; r = 0.588, P < 0.05, respectively). CONCLUSIONS: The lung bacterial burden tended to be increased, and the alpha diversity was significantly decreased in ARDS patients. The decreased Betaproteobacteria and increased Staphylococcus, Streptococcus and Enterobacteriaceae might represent a unique microbial community structure correlated with increased serum IL-6 and hospital mortality. TRIAL REGISTRATION: The institutional review boards of Hiroshima University (Trial registration: E-447-4, registered 16 October 2019) and Kyoto Prefectural University of Medicine (Trial registration: ERB-C-973, registered 19 October 2017) approved an opt-out method of informed consent.

Ultra-Protective Ventilation Reduces Biotrauma in Patients on Venovenous Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome.

INTRODUCTION: Ventilator settings for patients with severe acute respiratory distress syndrome supported by venovenous extracorporeal membrane oxygenation are currently set arbitrarily. The impact on serum and pulmonary biotrauma markers of the transition to ultra-protective ventilation settings following extracorporeal membrane oxygenation implantation, and different mechanical ventilation strategies while on extracorporeal membrane oxygenation were investigated. DESIGN: Randomized clinical trial. SETTINGS: Nine-month monocentric study. PATIENTS: Severe acute respiratory distress syndrome patients on venovenous extracorporeal membrane oxygenation. INTERVENTIONS: After starting extracorporeal membrane oxygenation, patients were switched to the bi-level positive airway pressure mode with 1 second of 24 cm H2O high pressure and 2 seconds of 12 cm H2O low pressure for 24 hours. A computer-generated allocation sequence randomized patients to receive each of the following three experimental steps: 1) high pressure 24 cm H2O and low pressure 20 cm H2O (very high positive end-expiratory pressure-very low driving pressure); 2) high pressure 24 cm H2O and low pressure 5 cm H2O (low positive end-expiratory pressure-high driving pressure); and 3) high pressure 17 cm H2O and low pressure 5 cm H2O (low positive end-expiratory pressure-low driving pressure). Plasma and bronchoalveolar lavage soluble receptor for advanced glycation end-products, plasma interleukin-6, and monocyte chemotactic protein-1 were sampled preextracorporeal membrane oxygenation and after 12 hours at each step. MEASUREMENTS AND MAIN RESULTS: Sixteen patients on ECMO after 7 days (1-11 d) of mechanical ventilation were included. "Ultra-protective" mechanical ventilation settings following ECMO initiation were associated with significantly lower plasma sRAGE, interleukin-6, and monocyte chemotactic protein-1 concentrations. Plasma sRAGE and cytokines were comparable within each on-ECMO experimental step, but the lowest bronchoalveolar lavage sRAGE levels were obtained at minimal driving pressure. CONCLUSIONS: ECMO allows ultra- protective ventilation, which combines significantly lower plateau pressure, tidalvolume, and driving pressure. This ventilation strategy significantly limited pulmonary biotrauma, which couldtherefore decrease ventilator-induced lung injury. However, the optimal ultra-protective ventilation strategy once ECMO is initiated remains undetermined and warrants further investigations. (Crit Care Med 2019; 47:1505-1512).

Experimental Hyperglycemia Alters Circulating Concentrations and Renal Clearance of Oxidative and Advanced Glycation End Products in Healthy Obese Humans.

The purpose of this investigation was to evaluate the effects of experimental hyperglycemia on oxidative damage (OX), advanced glycation end products (AGEs), and the receptor for AGEs (RAGE) through an in vivo approach. Obese subjects (n = 10; 31.2 ± 1.2 kg·m-2; 56 ± 3 years) underwent 24 h of hyperglycemic clamp (+5.4 mM above basal), where plasma at basal and after 2 h and 24 h of hyperglycemic challenge were assayed for OX (methionine sulfoxide, MetSO, and aminoadipic acid, AAA) and AGE-free adducts (Ne-carboxymethyllysine, CML; Ne-carboxyethyllysine, CEL; glyoxal hydroimidazolone-1, GH-1; methylglyoxal hydroimidazolone-1, MG-H1; and 3-deoxyglucosone hydroimidazolone, 3DG-H) via liquid chromatography⁻tandem mass spectrometry (LC⁻MS/MS). Urine was also analyzed at basal and after 24 h for OX and AGE-free adducts and plasma soluble RAGE (sRAGE) isoforms (endogenous secretory RAGE, esRAGE, and cleaved RAGE, cRAGE), and inflammatory markers were determined via enzyme-linked immunosorbent assay (ELISA). Skeletal muscle tissue collected via biopsy was probed at basal, 2 h, and 24 h for RAGE and OST48 protein expression. Plasma MetSO, AAA, CEL, MG-H1, and G-H1 decreased (-18% to -47%; p < 0.05), while CML increased (72% at 24 h; p < 0.05) and 3DG-H remained unchanged (p > 0.05) with the hyperglycemic challenge. Renal clearance of MetSO, AAA, and G-H1 increased (599% to 1077%; p < 0.05), CML decreased (-30%; p < 0.05), and 3DG-H, CEL, and MG-H1 remained unchanged (p > 0.05). Fractional excretion of MetSO, AAA, CEL, G-H1, and MG-H1 increased (5.8% to 532%; p < 0.05) and CML and 3DG-H remained unchanged (p > 0.05). Muscle RAGE and OST48 expression, plasma sRAGE, IL-1ß, IL-1Ra, and TNFα remained unchanged (p > 0.05), while IL-6 increased (159% vs. basal; p > 0.05). These findings suggest that individuals who are obese but otherwise healthy have the capacity to prevent accumulation of OX and AGEs during metabolic stress by increasing fractional excretion and renal clearance.

Lung fluid biomarkers for acute respiratory distress syndrome: a systematic review and meta-analysis.

BACKGROUND: With the development of new techniques to easily obtain lower respiratory tract specimens, bronchoalveolar lavage fluid and other lung fluids are gaining importance in pulmonary disease diagnosis. We aimed to review and summarize lung fluid biomarkers associated with acute respiratory distress syndrome diagnosis and mortality. METHODS: After searching PubMed, Embase, Web of Science, and the Cochrane Library for articles published prior to January 11, 2018, we performed a meta-analysis on biomarkers for acute respiratory distress syndrome diagnosis in at-risk patients and those related to disease mortality. From the included studies, we then extracted the mean and standard deviation of the biomarker concentrations measured in the lung fluid, acute respiratory distress syndrome etiologies, sample size, demographic variables, diagnostic criteria, mortality, and protocol for obtaining the lung fluid. The effect size was measured by the ratio of means, which was then synthesized by the inverse-variance method using its natural logarithm form and transformed to obtain a pooled ratio and 95% confidence interval. RESULTS: In total, 1156 articles were identified, and 49 studies were included. Increases in total phospholipases A2 activity, total protein, albumin, plasminogen activator inhibitor-1, soluble receptor for advanced glycation end products, and platelet activating factor-acetyl choline were most strongly associated with acute respiratory distress syndrome diagnosis. As for biomarkers associated with acute respiratory distress syndrome mortality, interleukin-1ß, interleukin-6, interleukin-8, Kerbs von Lungren-6, and plasminogen activator inhibitor-1 were significantly increased in the lung fluid of patients who died. Decreased levels of Club cell protein and matrix metalloproteinases-9 were associated with increased odds for acute respiratory distress syndrome diagnosis, whereas decreased levels of Club cell protein and interleukin-2 were associated with increased odds for acute respiratory distress syndrome mortality. CONCLUSIONS: This meta-analysis provides a ranking system for lung fluid biomarkers, according to their association with diagnosis or mortality of acute respiratory distress syndrome. The performance of biomarkers among studies shown in this article may help to improve acute respiratory distress syndrome diagnosis and outcome prediction.

Microplate-based Assay for Screening of Advanced Glycation End Products Binding to Its Receptor.

Advanced Glycation End products (AGEs) are a group of amino-acid modifications produced with sugars or di-carbonyls. Some AGEs are known to affect health through binding to the receptor of AGEs (RAGE). Here, we propose a method for screening RAGE-binding AGEs by a competitive assay using purified RAGE and AGEs-specific antibody. This method has clarified that at least carboxyethyl lysine and pentosidine among methylglyoxal-derived AGEs are involved in RAGE binding, suggesting that this would be a promising method for classifying RAGE-binding AGEs.

Quantification of the soluble Receptor of Advanced Glycation End-Products (sRAGE) by LC-MS after enrichment by strong cation exchange (SCX) solid-phase extraction (SPE) at the protein level.

The study of low abundant proteins contributes to increasing our knowledge about (patho)physiological processes and may lead to the identification and clinical application of disease markers. However, studying these proteins is challenging as high-abundant proteins complicate their analysis. Antibodies are often used to enrich proteins from biological matrices prior to their analysis, though antibody-free approaches have been described for some proteins as well. Here we report an antibody-free workflow on the basis of strong cation exchange (SCX) enrichment and liquid chromatography-mass spectrometry (LC-MS) for quantification of the soluble Receptor of Advanced Glycation End-products (sRAGE), a promising biomarker in chronic obstructive pulmonary disease (COPD). sRAGE was quantified in serum at clinically relevant low to sub ng mL-1 levels. The method was validated according to U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines and was compared to an antibody-based LC-MS sRAGE method. The SCX-based method builds upon the bipolar charge distribution of sRAGE, which has a highly basic N-terminal part and an acidic C-terminal part resulting in an overall neutral isoelectric point (pI). The highly basic N-terminal part (pIcalculated = 10.3) allowed for sRAGE to be enriched by SCX at pH 10, a pH at which most serum proteins do not bind. This study shows that ion exchange-based enrichment is a viable approach for the LC-MS analysis of several low abundant proteins following a thorough analysis of their physical-chemical properties.

Dynamic fluctuations of advanced glycation end products and its C-terminal truncated receptor level in patients with acute ST-segment elevation myocardial infarction and undergoing diabetes or not: A retrospective study.

The role of advanced glycation end products (AGEs) and its C-terminal truncated receptor (soluble receptor for advanced glycation end products, sRAGE) in ST-segment elevation myocardial infarction (STEMI) patients with or without diabetes is unknown. We compared their levels in patients with and without STEMI, as well as with and without diabetes. A prospective observational study was performed between December 2014 and December 2015. Study group included STEMI patients with coronary artery disease; control group included patients without coronary artery disease. Levels of AGEs and sRAGE were tested on Days 0, 2, and 5 after STEMI. Levels of creatine kinase-MB (CK-MB), cardiac troponin I, and N-terminal pro-brain natriuretic peptide (NT-proBNP) were tested on Days 0, 1, 2, and 3. Patient's diabetic status was determined by medical history or oral glucose tolerance test. Compared to patients in the control group, STEMI patients showed elevated levels of AGEs and sRAGE. In the STEMI group, diabetic patients had higher levels of AGEs and sRAGE compared to nondiabetic patients. The level of AGEs correlated with peak level of CK-MB in the overall population of patients with STEMI and with peak level of NT-proBNP in diabetic patients with STEMI. Levels of AGEs and sRAGE were elevated after STEMI, especially among patients with diabetes. These markers could serve to indicate the severity of myocardial injury and cardiac insufficiency, and play a potential role in predicting the prognosis of patients with STEMI.

Involvement of S100A4/Mts1 and associated proteins in the protective effect of fluoxetine against MCT - Induced pulmonary hypertension in rats.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a complex pulmonary vasculature disease characterized by remodeling of the pulmonary vessels and a persistent increase in the pulmonary vascular resistance (PVR) with a poor prognosis. Serotonin increases the expression of S100A4/Mts1, which in turn stimulates the proliferation and migration of human pulmonary artery smooth muscle cells through the interaction with RAGE (receptor for advanced glycation end products) and thus S100A4/Mts1 has been implicated in the development of PAH in vitro. Fluoxetine, a selective serotonin re-uptake inhibitor has been shown to protect against PAH. The current study was designed to test whether S100A4 and its associated proteins connected in the development of PAH in vivo as well as to investigate the involvement of those proteins in the protective effect of fluoxetine against PAH. METHODS: MCT-induced PAH models were established in Wistar rats by a single intraperitoneal injection of MCT (60 mg/kg). Fluoxetine (2 and 10 mg/kg/day) was intragastrically administered once a day for 3 weeks along with controls. The detection methods followed include Hematoxylin and Eosin (H&E) staining, immunohistochemistry, western blotting and real-time reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: MCT induced pulmonary hypertension, pulmonary vascular remodeling, and right ventricular hypertrophy significantly increased the expressions of S100A4 and RAGE in the pulmonary arteries, lungs and right ventricle (RV). Fluoxetine dose-dependently inhibited MCT-induced pulmonary arterial hypertension, pulmonary vascular remodeling, and right ventricular hypertrophy and reduced the S100A4 and RAGE. Further analysis revealed that fluoxetine alleviated both the increase of p53, MMP13, MMP2 and MMP9 and the decrease of pp53Ser15 and MDM2 in lungs and RV tissues of MCT-induced PAH rats. CONCLUSION: From the present investigation it could be concluded that S100A4/Mts1 and its associated proteins are involved in the evolution of MCT-induced PAH in rats and fluoxetine inhibits MCT-induced PAH in rats mainly through S100A4/RAGE signaling axis and involved factors.

RAGE-specific single chain Fv for PET imaging of pancreatic cancer.

Noninvasive detection of both early pancreatic neoplasia and metastases could enhance strategies to improve patient survival in this disease that is notorious for an extremely poor prognosis. There are almost no identifiable targets for non-invasive diagnosis by positron emission tomography (PET) for patients with pancreatic ductal adenocarcinoma (PDAC). Over-expression of the receptor for advanced glycation end products (RAGE) is found on the cell surface of both pre-neoplastic lesions and invasive PDAC. Here, a RAGE-specific single chain (scFv) was developed, specific for PET imaging in syngeneic mouse models of PDAC. An anti-RAGE scFv conjugated with a sulfo-Cy5 fluorescence molecule showed high affinity and selectivity for RAGE expressing pancreatic tumor cells and genetically engineered KRASG12D mouse models of PDAC. An in vivo biodistribution study was performed with the 64Cu-radiolabled scFv in a syngeneic murine pancreatic cancer model, demonstrating both the feasibility and potential of an anti-RAGE scFv for detection of PDAC. These studies hold great promise for translation into the clinic.

Biomarkers for patients with trauma associated acute respiratory distress syndrome.

Trauma is a major factor that contributes to the risk for acute respiratory distress syndrome (ARDS). Biomarkers that predict the risk, diagnosis, treatment response and prognosis of ARDS after trauma have been widely investigated. In addition to their applications in clinical diagnosis and treatment, these biomarkers provide important insights into our understanding of the pathogenesis of ARDS. This review begins with a brief introduction regarding the incidence and pathogenesis of trauma-associated ARDS. Then, we focus on reviewing the clinical trials that have been designed to investigate the value of biomarkers in ARDS after trauma. Biomarkers with a confirmed value in ARDS have been organized on the basis of key pathogenic processes that are central to ARDS and are described in detail. Among these, angiopoietin 2 (Ang-2), L-selectin, Clara cell protein 16 (CC16), soluable receptor for advanced glycation end products (sRAGE), Surfactant protein D (SP-D), histones, mtDNAs and some biomarker panels had a certain association with the diagnosis and prognosis of trauma-related ARDS. Further investigations are needed regarding the design of trials, the best sampling approaches and the optimal combinations of the biomarker panels.

sRAGE Is Elevated in the Lungs of Premature Infants Receiving Mechanical Ventilation.

Background Soluble receptor for advanced glycation end-products (sRAGE), a soluble isoform of the RAGE receptor, is elevated in lungs from patients with acute conditions such as acute respiratory distress syndrome and bronchiolitis. This study investigated whether sRAGE is present in ventilated infants. Methods Tracheal aspirates from the first week or the fifth week of life were obtained from intubated very low birth weight subjects and analyzed by Western blot. Immunohistochemistry analysis for sRAGE was performed on paraffin-embedded lung autopsy slides from 19 other infants. Results The sRAGE band densities were similar among the seven infants who fully recovered, eight who developed bronchopulmonary dysplasia (BPD), and 5 who died (analysis of variance p = 0.797) but was higher at 4 weeks, p = 0.0324. There was minimal sRAGE staining in the autopsied lungs from previable infants (20-21 weeks) or from those who were not ventilated or had mild lung disease. In contrast, substantial staining was present in two of three with BPD, and those who received high ventilatory support. Conclusion sRAGE is present in ventilated infants. Levels are generally higher in those who receive prolonged or vigorous mechanical ventilation. Since sRAGE may have roles in inflammation and cell adherence, its role in the development of BPD may warrant study.

Inhibition of Methylglyoxal-Induced AGEs/RAGE Expression Contributes to Dermal Protection by N-Acetyl-L-Cysteine.

BACKGROUND/AIM: Accumulation of advanced glycation end products (AGEs) is a major cause of diabetes mellitus (DM) skin complications. Methylglyoxal (MGO), a reactive dicarbonyl compound, is a crucial intermediate of AGEs generation. N-acetyl-L-cysteine (NAC), an active ingredient of some medicines, can induce endogenous GSH and hydrogen sulfide generation, and set off a condensation reaction with MGO. However, there is rare evidence to show NAC can alleviate DM-induced skin injury through inhibition of AGEs generation or toxicity. The present study aimed to observe the effects of NAC on MGO-induced inflammatory injury and investigate the roles of AGEs and its receptor (RAGE) in NAC's dermal protection in human HaCaT keratinocytes. METHODS: The cells were exposed to MGO to simulate a high MGO status in diabetic blood or tissues. The content of AGEs in serum or cell medium was measured with ELISA. The protective effects of NAC against MGO-induce injury were evaluated by administration before MGO one hour, in virtue of cell viability, mitochondrial membrane potential, inflammation reaction, nuclear factor (NF)-κB activation, matrix metalloproteinase (MMP)-9 expression, as well as cellular behavioral function. RESULTS: We found the AGEs levels of patients with DM were elevated comparing with healthy volunteers. The in vitro AGEs generation was also able to be enhanced by the exposure of HaCaT cells to MGO, which reduced dose-dependently cellular viability, damaged mitochondrial function, triggered secretion of interleukin (IL)-6 and IL-8, activated NF-κB and upregulated MMP-9 expression. Furthermore, the exposure caused cellular adhesion and migration dysfunction, as well as collagen type I inhibition. Importantly, before the exposure to MGO, the preconditioning with NAC significantly attenuated MGO-induced AGEs generation, improved cellular viability and mitochondrial function, partially reversed the overexpression of proinflammatory factors and MMP-9, as well as the activation of NF-κB. Lastly, NAC blocked MGO-induced RAGE upregulation, and inhibition of RAGE with its neutralizing antibody significantly alleviated MGO-induced NF-κB activation, MMP-9 upregulation and inflammatory injury in HaCaT cells. CONCLUSION: The present work indicates the administration of NAC can prevent MGO-induced dermal inflammatory injury through inhibition of AGEs/RAGE signal, which may provide a basal support for the treatment of diabetic skin complications with NAC-containing medicines in the future.

Fraction of exhaled nitric oxide and soluble receptors for advanced glycation end products are negatively correlated in children with recurrent wheezing.

BACKGROUND: The fraction of exhaled nitric oxide (FeNO) and serum levels of the soluble receptor for advanced glycation end products (sRAGE) have been suggested as biomarkers for asthma. OBJECTIVE: This study aimed to assess the correlation between FeNO and sRAGE serum levels in children <5 years old with recurrent wheezing. METHOD: In total, 88 children with recurrent wheezing were divided into the high-risk group or low-risk group according to their clinical features. The high-risk group included 60 children, 42 male and 18 female, average age 36.7 months (range 32-48.7 months); the low-risk group included 28 children, 20 male and 8 female, average age 38.1 months (range 33-46.2 months).Asthma in high-risk children was treated with aerosol inhalation of Pulmicort respules 1 mg/d for four continuous weeks, while asthma in low-risk children was treated with symptomatic treatment. FeNO, serum sRAGE and eosinophils (EOS) were examined by ELISA and a regular blood cell analyzer. RESULTS: The serum sRAGE level was 738±191 and 992.4±210 pg/ml and the mean FeNO level was 27.3 and 17.6 ppm, respectively, in the asthma high-risk and low-risk group, showing significant differences between the two groups. In addition, FeNO and sRAGE serum levels were negatively correlated.After the inhalation of Pulmicort respules, FeNO decreased and sRAGE increased, while EOS showed no significant change. CONCLUSIONS: FeNO and sRAGE serum levels are negatively correlated in children with recurrent wheezing. Further larger scale studies are needed to test the use of FeNO and sRAGE as biomarkers for the prediction of asthma in children.

Cytoplasmic translocation of high-mobility group box-1 protein is induced by diabetes and high glucose in retinal pericytes.

The aim of the present study was to assess the involvement of the high-mobility group box-1 (HMGB1) protein, receptor for advanced glycation end products (RAGE) and nuclear factor (NF)-κB signaling pathway in the development of diabetic retinopathy. Rat primary retinal pericytes were exposed to 25 mmol/l D­glucose for 48 h. Diabetic retinal vessels were prepared from streptozotocin-induced diabetic rats 12 weeks following the induction of diabetes. The expression of HMGB1 was detected using immunofluorescence staining. The expression of RAGE and the activity of NF­κB were analyzed using western blot and electrophoretic mobility shift assays, respectively. The results showed that HMGB1 was translocated to the cytoplasm of the high glucose­treated pericytes and diabetic retinal pericytes, whereas, in the control cells and the normal retinas, HMGB1 was expressed in the cell nuclei only. The expression of RAGE, a potential receptor for HMGB1, and the activity of NF­κB were also increased in the high glucose­treated pericytes, compared with the normal control cells. In addition, high glucose increased the binding of NF­κB to the RAGE promoter. These findings suggested that the cytoplasmic translocation of HMGB1 may be caused by diabetes and high glucose in retinal pericytes, and that the pathogenic role of HMGB1 may be dependent on the expression of RAGE and activation of NF­κB.