PEDF, a pleiotropic WTC-LI biomarker: Machine learning biomarker identification and validation.

Biomarkers predict World Trade Center-Lung Injury (WTC-LI); however, there remains unaddressed multicollinearity in our serum cytokines, chemokines, and high-throughput platform datasets used to phenotype WTC-disease. To address this concern, we used automated, machine-learning, high-dimensional data pruning, and validated identified biomarkers. The parent cohort consisted of male, never-smoking firefighters with WTC-LI (FEV1, %Pred< lower limit of normal (LLN); n = 100) and controls (n = 127) and had their biomarkers assessed. Cases and controls (n = 15/group) underwent untargeted metabolomics, then feature selection performed on metabolites, cytokines, chemokines, and clinical data. Cytokines, chemokines, and clinical biomarkers were validated in the non-overlapping parent-cohort via binary logistic regression with 5-fold cross validation. Random forests of metabolites (n = 580), clinical biomarkers (n = 5), and previously assayed cytokines, chemokines (n = 106) identified that the top 5% of biomarkers important to class separation included pigment epithelium-derived factor (PEDF), macrophage derived chemokine (MDC), systolic blood pressure, macrophage inflammatory protein-4 (MIP-4), growth-regulated oncogene protein (GRO), monocyte chemoattractant protein-1 (MCP-1), apolipoprotein-AII (Apo-AII), cell membrane metabolites (sphingolipids, phospholipids), and branched-chain amino acids. Validated models via confounder-adjusted (age on 9/11, BMI, exposure, and pre-9/11 FEV1, %Pred) binary logistic regression had AUCROC [0.90(0.84-0.96)]. Decreased PEDF and MIP-4, and increased Apo-AII were associated with increased odds of WTC-LI. Increased GRO, MCP-1, and simultaneously decreased MDC were associated with decreased odds of WTC-LI. In conclusion, automated data pruning identified novel WTC-LI biomarkers; performance was validated in an independent cohort. One biomarker-PEDF, an antiangiogenic agent-is a novel, predictive biomarker of particulate-matter-related lung disease. Other biomarkers-GRO, MCP-1, MDC, MIP-4-reveal immune cell involvement in WTC-LI pathogenesis. Findings of our automated biomarker identification warrant further investigation into these potential pharmacotherapy targets.

Plasma angiogenesis and oxidative stress markers in patients with diabetic retinopathy.

Background: Neovascularization in the retina and hyperglycaemia-induced oxidative stress are implicated in the pathogenesis of diabetic retinopathy (DR). In this study, we hypothesized that the plasma angiogenic and oxidative stress markers associated with these derangements could aid in the screening of diabetic patients who are at an increased risk of developing retinopathy.Methods: This study included normal (n = 148), type2 diabetes without retinopathy (DNR; n = 148), proliferative DR (PDR; n = 74) and non-PDR (NPDR; n = 148) subjects. Plasma concentrations of vascular endothelial growth factor-A (VEGF-A), hypoxia-inducible factor-1α (HIF-1α), matrix metalloproteinase-9 (MMP-9), pigment epithelium-derived factor (PEDF), nitric oxide (NO), soluble receptors for advanced glycation end products (sRAGE), malondialdehyde (MDA) and protein thiols were estimated.Results: A statistically significant increase was observed in the plasma concentrations of pro-angiogenic factors and markers of oxidative stress in both retinopathy groups. By contrast, the concentrations of anti-angiogenic factors and antioxidants were decreased significantly in these groups. Receiver operating characteristic analysis indicated that the plasma thresholds of HIF-1α and PEDF can be suitable markers in case of NPDR. However, in PDR, HIF-1α, NO, MMP-9 and PEDF showed high sensitivity and specificity.Conclusions: The factors associated with hypoxia, matrix degradation and angiogenic inhibition play a crucial role in predicting DR.

Insulin resistance is associated with Sfrp5 in obstructive sleep apnea / Resistência à insulina está associada à Sfrp5 na apneia obstrutiva do sono

Abstract Introduction: Obstructive sleep apnea, a common disease, is usually complicated by insulin resistance and type 2 diabetes mellitus. Adipokine is considered to play an important role in the development of insulin resistance and type 2 diabetes mellitus in obstructive sleep apnea. Objective: To assess whether secreted frizzled-related protein 5, a new adipokine, is involved in untreated obstructive sleep apnea patients. Methods: Seventy-six subjects with obstructive sleep apnea and thirty-three control subjects without obstructive sleep apnea were recruited and matched in terms of body mass index and age. The fasting secreted frizzled-related protein 5 plasma concentration was tested using ELISA. In addition, the correlation between secreted frizzled-related protein 5 and the homeostasis model assessment of insulin resistance was obtained. Multiple linear regression analysis models with stepwise selection were performed to determine the independent associations between various factors and secreted frizzled-related protein 5. Results: Plasma secreted frizzled-related protein 5 levels were significantly lower in the obstructive sleep apnea group than in the control group (obstructive sleep apnea group: 28.44 ± 13.25 ng/L; control group: 34.16 ± 13.51 ng/L; p = 0.023). In addition, secreted frizzled-related protein 5 was negatively correlated with homeostasis model assessment of insulin resistance but positively correlated with the mean and lowest oxygen saturation with or without adjusting for age, gender, body mass index, neck circumference, waist circumference and waist-to-hip ratio. The multiple linear regression analysis showed there was an independent negative association between secreted frizzled-related protein 5 and homeostasis model assessment of insulin resistance. Conclusion: Secreted frizzled-related protein 5 was involved in obstructive sleep apnea and the decrease in secreted frizzled-related protein 5 was directly proportional to the severity of obstructive sleep apnea. There was an independent negative correlation between homeostasis model assessment of insulin resistance and secreted frizzled-related protein 5 in the obstructive sleep apnea group. Secreted frizzled-related protein 5 might be a therapeutic target for insulin resistance in obstructive sleep apnea.

Resumo Introdução: A apneia obstrutiva do sono, uma doença comum, é geralmente complicada com resistência à insulina e diabetes melito tipo 2. Acredita-se que a adipocina possa ter um papel importante no desenvolvimento de resistência à insulina e diabetes melito tipo 2 na apneia obstrutiva do sono. Objetivo: Avaliar se a proteína secretada relacionada ao receptor frizzled-5, uma nova adipocina, está envolvida em pacientes com apneia obstrutiva do sono não tratada. Método: Foram recrutados 76 indivíduos com apneia obstrutiva do sono e 33 indivíduos controle sem apneia obstrutiva do sono e pareados em relação a índice de massa corporal e idade. A concentração plasmática de proteína secretada relacionada ao receptor frizzled-5 foi testada em jejum com o teste Elisa. Além disso, obteve-se correlação entre a proteína secretada relacionada ao receptor frizzled-5 e o modelo de avaliação da homeostase de resistência à insulina. Modelos de análise de regressão linear múltipla com seleção stepwise foram feitos para determinar as associações independentes entre vários fatores e a proteína secretada relacionada ao receptor frizzled-5. Resultados: Os níveis plasmáticos de proteína secretada relacionada ao receptor frizzled-5 foram significativamente menores no grupo com apneia obstrutiva do sono do que no grupo controle (grupo com apneia obstrutiva do sono: 28,44 ± 13,25 ng/L; grupo controle: 34,16 ± 13,51 ng/L; p = 0,023). Além disso, a proteína secretada relacionada ao receptor frizzled-5 foi correlacionada negativamente com o modelo de avaliação da homeostase de resistência à insulina, mas se correlacionou positivamente com a média e a saturação mínima de oxigênio com ou sem ajuste para idade, gênero, índice de massa corporal, circunferência do pescoço, circunferência da cintura e relação cintura-quadril. A análise de regressão linear múltipla mostrou que houve uma associação negativa independente entre a proteína secretada relacionada ao receptor frizzled-5 e o modelo de avaliação da homeostase de resistência à insulina. Conclusões: A proteína secretada relacionada ao receptor frizzled-5 esteve envolvida na apneia obstrutiva do sono e sua diminuição foi diretamente proporcional à gravidade da apneia obstrutiva do sono. Houve uma correlação negativa independente entre o modelo de avaliação da homeostase de resistência à insulina e a proteína secretada relacionada ao receptor frizzled-5 no grupo da apneia obstrutiva do sono. A proteína secretada relacionada ao receptor frizzled-5 pode ser um alvo terapêutico para a resistência à insulina na apneia obstrutiva do sono.

Retinol binding protein 3 is increased in the retina of patients with diabetes resistant to diabetic retinopathy.

The Joslin Medalist Study characterized people affected with type 1 diabetes for 50 years or longer. More than 35% of these individuals exhibit no to mild diabetic retinopathy (DR), independent of glycemic control, suggesting the presence of endogenous protective factors against DR in a subpopulation of patients. Proteomic analysis of retina and vitreous identified retinol binding protein 3 (RBP3), a retinol transport protein secreted mainly by the photoreceptors, as elevated in Medalist patients protected from advanced DR. Mass spectrometry and protein expression analysis identified an inverse association between vitreous RBP3 concentration and DR severity. Intravitreal injection and photoreceptor-specific overexpression of RBP3 in rodents inhibited the detrimental effects of vascular endothelial growth factor (VEGF). Mechanistically, our results showed that recombinant RBP3 exerted the therapeutic effects by binding and inhibiting VEGF receptor tyrosine phosphorylation. In addition, by binding to glucose transporter 1 (GLUT1) and decreasing glucose uptake, RBP3 blocked the detrimental effects of hyperglycemia in inducing inflammatory cytokines in retinal endothelial and Müller cells. Elevated expression of photoreceptor-secreted RBP3 may have a role in protection against the progression of DR due to hyperglycemia by inhibiting glucose uptake via GLUT1 and decreasing the expression of inflammatory cytokines and VEGF.

Clinical Significance of Serum Vascular Endothelial Growth Factor, Pigment Epithelium-Derived Factor, Tumor Necrosis Factor Alpha, and Progranulin Levels in Patients with Gastric Cancer and Gastric Precancerous Lesions.

BACKGROUND: The purpose of this study is to evaluate serum levels of vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), tumor necrosis factor alpha (TNF-α), and progranulin in patients with gastric cancer (GC) and precancerous lesions (PCL) and to determine the usefulness of these markers as diagnostic biomarkers in these diseases. METHOD: A total of 32 GC patients, 35 PCL patients, and 23 healthy controls participated in the study. The serum levels of VEGF, PEDF, TNF-α, and progranulin were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean serum VEGF levels were 30.6 ± 12.98 pg/mL in GC, 18.2 ± 5.72 pg/mL in PCL, and 17.5 ± 5.59 pg/mL in controls. GC VEGF levels were significantly higher than both PCL and control groups (p < 0.001). The mean serum PEDF levels were 1516.1 ± 993.8 pg/mL in GC, 1039.1 ± 1002.3 pg/mL in PCL, and 767.5 ± 661.5 pg/mL in controls. The serum PEDF level in the GC group was significantly higher than that in both PCL and control groups (p = 0.004 and p = 0.038, respectively). The mean serum TNF-α levels were 46.7 ± 14.82 pg/mL in GC, 38.4 ± 11.89 pg/mL in PCL, and 33.8 ± 12.77 pg/mL in controls. There was a significant difference between GC and controls (p = 0.022) in TNF-α levels. The mean serum progranulin levels in GC were 2496.6 ± 737.8 pg/mL, 2332.0 ± 482.1 pg/mL in PCL, and 1288.7 ± 830.9 pg/mL in controls. Progranulin levels in both GC and PCL groups were significantly higher than that in the control group (p < 0.001 for both). CONCLUSION: There were significant differences among patients with GC and PCL and healthy controls in terms of serum VEGF, PEDF, TNF-α, and progranulin levels.

Association of pigment epithelium derived factor with von Willebrand factor and plasminogen activator inhibitor 1 in patients with type 2 diabetes.

To compare circulating pigment epithelium derived factor (PEDF) levels in type 2 diabetes patients (T2D) with and without metabolic syndrome (MetS+/-) to healthy controls and assess PEDF association with plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor (vWF) as markers of endothelial dysfunction. Fifty T2D individuals and forty healthy controls were included. PEDF, PAI-1, vWF, anthropological parameters, lipids, and markers of insulin resistance were investigated in all subjects. Compared to controls only MetS+ diabetics had higher PEDF levels [14.2 (10.2-16.0) mg/l vs. 11.1 (8.6-14.4) mg/l; p<0.05]. PEDF significantly correlated: positively with body mass index (rho=0.25), smoking (rho=0.21), C-reactive protein (rho=0.22), triglycerides (rho=0.38), non-HDL-cholesterol (rho=0.39), apolipoprotein B (rho=0.38), fasting glucose (rho=0.22), glycated hemoglobin (rho=0.24), C-peptide (rho=0.28), insulin (rho=0.26); and negatively with HDL-cholesterol (rho=-0.42) and apolipoprotein A1 (rho=-0.27). Independent association of PEDF with vWF in T2DMetS- subjects was found. Significantly elevated PEDF in T2DMet+ patients and its association with adverse metabolic profile confirmed PEDF as a marker of insulin resistance. Negative independent association of PEDF with vWF in T2DMetS- patients may reveal its angio-protective role.

Pigment Epithelium-Derived Factor Affects Angiogenesis in Celiac Disease.

OBJECTIVE: Recent studies have demonstrated that angiogenesis is impaired in patients with celiac disease (CD). In this study, we evaluated the levels of the novel antiangiogenic factor pigment epithelium-derived factor (PEDF) in CD patients. METHODS: Eighty-four patients were included in the study; 71 patients with CD and 13 healthy controls. In the CD patient cohort, there were 21 newly diagnosed patients, 19 with adherence to a gluten-free diet and 31 practicing no adherence to this diet. The PEDF levels were measured using enzyme-linked immunosorbent assays. RESULTS: The data revealed that celiac patients had higher levels of PEDF than did healthy controls. PEDF levels were not significantly different among the three CD groups. Additionally, the PEDF levels were not correlated with tissue transglutaminase IgA or IgG. CONCLUSIONS: Our data indicate that PEDF levels are significantly higher in CD patients than those in the healthy controls. This result suggests that PEDF negatively affects angiogenesis in CD. Although we did not observe any differences of PEDF levels among celiac patients, additional studies including more patients could clarify this issue.

Pigment epithelium-derived factor/vascular endothelial growth factor ratio for early prediction of preeclampsia: A prospective multicenter study in China.

BACKGROUND: Imbalance of circulating factors related to angiogenesis plays a central role in the pathogenesis of preeclampsia (PE). OBJECTIVE: The aim of this study was to discover and validate a cutoff value of pigment epithelium-derived factor (PEDF)/vascular endothelial growth factor (VEGF) ratio for early prediction of PE before 20 weeks of gestation. STUDY DESIGN: This prospective multicenter study was performed in mainland China, and was divided into 3 phases to discover, develop, and validate a cutoff value of PEDF/VEGF ratio that could predict PE prior to diagnosis in pregnant women at high risk of PE (12 weeks 0 days to 19 weeks 6 days of gestation). We estimated PEDF/VEGF ratio at 5 visits: from visit 0 (baseline) to the postpartum visit. RESULTS: In the discovery phase (200 women), we found that antiangiogenic PEDF was higher and angiogenic VEGF was lower in the PE group than in the control group before 20 weeks of gestation. In the development phase (650 women), we found that a cutoff value of 800 for PEDF/VEGF ratio demonstrated a preferably predictive value. Subsequently, in the validation phase (additional 900 women), we found that the negative predictive value of PEDF/VEGF ratio ≤800 at the visit 1 was 98.6% (95% CI, 97.3-99.4), at the visit 2 was 96.9% (95% CI, 95.1-98.1) and at the visit 3 was 95.1% (95% CI, 93.0-96.7). ORs were 4.40, 6.27, and 5.73, respectively. CONCLUSIONS: PEDF/VEGF ratio ≤800 may have some predictive value for early diagnosis of PE. Further multicenter studies with larger sample sizes are necessary to confirm our findings.

Role of wnt5a in Metabolic Inflammation in Humans.

Context: Common nutrition-associated diseases like obesity and type 2 diabetes are linked to chronic low-grade inflammation. The secreted glycopeptide wingless-type mouse mammary tumor virus integration site family member 5a (wnt5a) has been implicated in metabolic inflammation in rodent models, suggesting a potential treatment target. Data on the role of wnt5a in human physiology have yielded conflicting results. Objective: Serum concentrations of wnt5a were measured in a cross-sectional cohort of 896 people to gain deeper insights into wnt5a physiology. Design: Serum concentrations of wnt5a were measured by ELISA and related to several phenotyping and genotyping data. In vitro experiments were performed in THP-1 macrophages to examine potential molecular mechanisms. Results: Wnt5a levels were significantly positively correlated to IL-6 and triglyceride levels. In subjects with diabetes, wnt5a levels were elevated and significantly correlated with fasting plasma glucose concentrations. Although wnt5a levels were not influenced by common single-nucleotide polymorphisms in the human wnt5a gene, environmental factors significantly altered wnt5a concentrations, as follows: (1) wnt5a levels were reduced in subjects with high nutritional load of the long-chain eicosatetraenoic acid independent of the total caloric intake and overall composition of the macronutrients, and (2) wnt5a levels were lower in humans with a high gut microbiome α diversity. In vitro experiments revealed that stimulation of the IL-6 receptor or the long-chain fatty acid receptor GPR40 directly affected wnt5a expression in human macrophages. Conclusion: Our data suggest that wnt5a is important in linking inflammation to metabolism. The nutrition and the microbiome might be interesting targets to prevent and/or treat wnt5a-mediated metabolic inflammation.

Circulating secreted frizzled-related protein 5 and chronic kidney disease in patients with acute ST-segment elevation myocardial infarction.

Secreted frizzled-related protein-5 (Sfrp5) known as secreted antagonist binds to Wnt protein. It has been shown to be downregulated by histone acetylation and promoter methylation, and to function as a tumor suppressor gene by inducing apoptosis in renal cell cancer cells. However, its relationship with chronic kidney disease (CKD) has not been well studied. Our objective was to investigate the effect of plasma Sfrp5 levels in subjects with and without CKD. Plasma Sfrp5 levels were determined by enzyme-linked immunosorbent assays in 196 consecutive patients with acute ST-segment elevation myocardial infarction (STEMI). CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2. For the purpose of this study, stage 1 or 2 CKD patients (eGFR ≥ 60 ml/min per 1.73 m2) were classified as not having CKD. With increasing Sfrp5 tertiles, the patients had higher frequencies of hypertension, stage 4 or 5 CKD, and waist-to-hip ratio, incrementally lower eGFRs and serum hemoglobin levels, and higher levels of blood urine nitrogen (BUN), creatinine, and adiponectin. Multivariate logistic regression analysis showed that an increased plasma Sfrp5 level was independently associated with CKD for all subjects (adjusted odds ratio (OR), 1.08; 95% confidence interval (CI), 1.02-1.14; p = 0.011). Sfrp5 was also significantly positively related to BUN, creatinine, and adiponectin, and significantly negatively related to eGFR and hemoglobin. When the patients were stratified by age, plasma Sfrp5 level was independently related to CKD for patients >65 years old (adjusted OR, 1.10; 95% CI, 1.00-1.20; p = 0.045), however, the association was not significant for those <65 years old. In addition, Sfrp5 was significantly positively related to BUN, creatinine, and adiponectin, and significantly negatively related to eGFR and hemoglobin in patients >65 years old. Our results suggest that Sfrp5 may play a role in the pathogenesis of CKD in acute STEMI patients who are older than 65 years.

Effect of SFRP5 (Secreted Frizzled-Related Protein 5) on the WNT5A (Wingless-Type Family Member 5A)-Induced Endothelial Dysfunction and Its Relevance With Arterial Stiffness in Human Subjects.

OBJECTIVE: SFRP5 (secreted frizzled-related protein 5) is an endogenous inhibitor of WNT5A (wingless-type family member 5a), which has been implicated in atherosclerosis. However, contradictory results have been reported about the role of SFRP5 in atherosclerosis. We aimed to investigate whether SFRP5 could restore WNT5A-induced endothelial dysfunction in vitro and ex vivo. In addition, we sought to determine whether the serum concentration of SFRP5 is associated with atherosclerosis in humans. APPROACH AND RESULTS: We measured endothelium-dependent vasorelaxation in the isolated thoracic aorta of Sprague-Dawley rats. In addition, we measured intracellular nitric oxide (NO) in human endothelial cells. The protein abundance of total and phosphorylated JNK (c-Jun N-terminal kinase), AKT (protein kinase B), and endothelial NO synthase was analyzed in human endothelial cells. Circulating SFRP5 and WNT5A levels and brachial-ankle pulse wave velocity were measured in 282 human subjects with type 2 diabetes mellitus. SFRP5 dose dependently restored Wnt5-induced impaired vasorelaxation in rat thoracic aorta by an endothelial NO synthase-dependent mechanism. SFRP5 treatment restored the WNT5A-induced reduction of NO production via endothelial NO synthase in human endothelial cells. WNT5A-induced changes in the phosphorylation of JNK, AKT, and endothelial NO synthase were ameliorated with SFRP5 administration. In humans with type 2 diabetes mellitus, the serum SFRP5 concentration positively correlated with brachial-ankle pulse wave velocity (r=0.146; P=0.024). Multivariate linear regression analysis demonstrated that the serum SFRP5 concentration was independently associated with brachial-ankle pulse wave velocity after adjustment for potential confounders [B (SE)=7.40 (3.35); P=0.028]. CONCLUSIONS: Our data suggest the possible compensatory action of SFRP5 against atherosclerosis under conditions of metabolic dysfunction.

Plasma levels of hypoxia-regulated factors in patients with age-related macular degeneration.

PURPOSE: Various hypoxia-related proteins are differentially expressed in the retina and secreted to the vitreous and/or aqueous humor of patients affected by dry or neovascular age-related macular degeneration (nAMD). To determine whether these conditions alter concentrations of cytokines also in the systemic circulation, we measured plasma levels of six hypoxia-related proteins. METHODS: Plasma was prepared from EDTA blood that was collected from patients affected by dry AMD (n = 5), nAMD (n = 11), proliferative diabetic retinopathy (PDR; n = 9), and patients with an epiretinal membrane (ERM; n = 11). ERM samples served as negative controls, PDR samples as positive controls. Protein concentrations of vascular endothelial growth factor (VEGF), erythropoietin (EPO), angiopoietin-like 4 (ANGPTL4), placental growth factor (PlGF), tumor necrosis factor alpha (TNF-α), and pigment epithelium-derived factor (PEDF) were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The concentration of PlGF was significantly increased in plasma of patients affected by nAMD. Although no statistically significant differences were found for EPO, ANGPTL4, PlGF, TNF-α, and PEDF, the mean concentration of VEGF was lowest in the nAMD group. Plasma concentrations of the six factors did not correlate with gender or age of patients. CONCLUSIONS: nAMD may increase plasma concentrations of PlGF, making it a candidate as a biomarker for the neovascular form of AMD. Other factors, however, were not differentially regulated, suggesting that their systemic concentrations are not generally increased in hypoxia-related retinal diseases.

Long-Term Effects of Weight Loss and Exercise on Biomarkers Associated with Angiogenesis.

Background: We tested the effect of weight loss on circulating levels of the angiogenic factors VEGF and pigment epithelium-derived factor (PEDF) in postmenopausal overweight/obese women, 18 months after completing a year-long 4-arm randomized controlled trial of behavioral weight loss and/or exercise versus control (i.e., 30 months postrandomization).Methods: The 439 overweight/obese, postmenopausal women, ages 50 to 75 years, were randomized to: diet (goal: 10% weight loss, N = 118), exercise (225 min/wk moderate-to-vigorous activity, N = 117), diet + exercise (N = 117), or control (N = 87). At 12 months, 399 women gave a blood sample; 156 returned at 30 months. Biomarkers were measured by immunoassay. Changes were compared using generalized estimating equations, adjusting for baseline BMI, age, and race/ethnicity.Results: Participants randomized to diet, exercise, and diet + exercise arms had greater reductions in VEGF at 30 months (-14.1% P = 0.02; -19.7% P = 0.003; -14.5% P = 0.002, respectively) versus controls (-4.5%). There were no statistically significant changes in PEDF in any intervention arm. Participants maintaining ≥10% of baseline weight loss at 30 months had greater reductions in VEGF versus those who gained weight/had no weight change (-22.3% vs. -10.2% respectively, P = 0.002). Participants maintaining any weight loss had significantly lower levels of PEDF at 30 months versus those who gained weight/no weight change.Conclusions: Sustained weight loss via diet and/or exercise results in reductions in angiogenic factors, and can be maintained up to 30-month follow-up. Limitations include relatively small numbers, and possible bias toward more successful weight loss among women who returned at 30 months.Impact: Maintaining weight loss can achieve long-term reductions in biomarkers of angiogenesis that can persist up to 18 months after completion of a weight loss intervention. Cancer Epidemiol Biomarkers Prev; 26(12); 1788-94. ©2017 AACR.

Peptides of the variable IgG domain as potential biomarker candidates in primary open-angle glaucoma (POAG).

Autoantibody profiling has gained increasing interest in the research field of glaucoma promising the detection of highly specific and sensitive marker candidates for future diagnostic purposes. Recent studies demonstrated that immune responses are characterized by the expression of congruent or similar complementarity determining regions (CDR) in different individuals and could be used as molecular targets in biomarker discovery. Main objective of this study was to characterize glaucoma-specific peptides from the variable region of sera-derived immunoglobulins using liquid chromatography--mass spectrometry (LC-MS)-based quantitative proteomics. IgG was purified from sera of 13 primary open-angle glaucoma patients (POAG) and 15 controls (CTRL) and subsequently digested into Fab and Fc by papain. Fab was further purified, tryptic digested and measured by LC-MS/MS. Discovery proteomics revealed in total 75 peptides of the variable IgG domain showing significant glaucoma-related level changes (P < 0.05; log2 fold change ≥ 0.5): 6 peptides were high abundant in POAG sera, whereas 69 peptides were low abundant in comparison to CTRL group. Via accurate inclusion mass screening strategy 28 IgG V domain peptides were further validated showing significantly decreased expression levels in POAG sera. Amongst others 5 CDR1, 2 CDR2 and 1 CDR3 sequences. In addition, we observed significant shifts in the variable heavy chain family distribution and disturbed κ/λ ratios in POAG patients in contrast to CTRL. These findings strongly indicate that glaucoma is accompanied by systemic effects on antibody production and B cell maturation possibly offering new prospects for future diagnostic or therapy purposes.

Diabetic nephropathy: serum miR-9 confers a poor prognosis in and is associated with level changes of vascular endothelial growth factor and pigment epithelium-derived factor.

OBJECTIVE: To investigate the relationship between the serum level of miR-9 and the progression of diabetic nephropathy (DN) and related molecular mechanisms. RESULTS: Thirty-five healthy subjects and 140 DN patients were divided into five groups: control, DN I-II, DN III, DN IV and DN V. Serum level of miR-9 was measured by real-time qPCR. Serum levels of vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF) lipids, fasting glucose, insulin, hemoglobin A1c (HBA1c), creatinine, fibrinogen and insulin resistance (HOMA-IR) were also measured. The results show that the levels of miR-9, PEDF and VEGF are increased with DN progression (P < 0.05). miR-9, VEGF and PEDF are independent risk factors of DN (R2 = 0.430). Spearman rank correlation analysis showed that miR-9 level is positively related to the levels of VEGF, PEDF, cholesterol, triglyceride, fasting glucose, fasting insulin, HBA1c, creatinine, fibrinogen and HOMA-IR (P < 0.05). CONCLUSIONS: Serum miR-9 is a potential marker for conferring a poor prognosis in DN and associated with the levels of VEGF, PEDF and biochemical indices.

High serum soluble tumor necrosis factor receptor 1 predicts poor treatment response in acute-stage schizophrenia.

Inflammation may be involved in the pathophysiology of schizophrenia. However, few cross-sectional or longitudinal studies have examined changes in biomarker expression to evaluate diagnostic and prognostic efficacy in acute-stage schizophrenia. We compared serum inflammatory biomarker concentrations in 87 patients with acute-stage schizophrenia on admission to 105 age-, sex-, and body mass index (BMI)-matched healthy controls. The measured biomarkers were soluble tumor necrosis factor receptor 1 (sTNFR1) and adiponectin, which are associated with inflammatory responses, and pigment epithelium-derived factor (PEDF), which has anti-inflammatory properties. We then investigated biomarker concentrations and associations with clinical factors in 213 patients (including 42 medication-free patients) and 110 unmatched healthy controls to model conditions typical of clinical practice. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale and Global Assessment of Function. In 121 patients, biomarker levels and clinical status were evaluated at both admission and discharge. Serum sTNFR1 was significantly higher in patients with acute-stage schizophrenia compared to matched controls while no significant group differences were observed for the other markers. Serum sTNFR1 was also significantly higher in the 213 patients compared to unmatched controls. The 42 unmedicated patients had significantly lower PEDF levels compared to controls. Between admission and discharge, sTNFR1 levels decreased significantly; however, biomarker changes did not correlate with clinical symptoms. The discriminant accuracy of sTNFR1 was 93.2% between controls and patients, showing no symptom improvement during care. Inflammation and a low-level anti-inflammatory state may be involved in both schizophrenia pathogenesis and acute-stage onset. High serum sTNFR1 in the acute stage could be a useful prognostic biomarker for treatment response in clinical practice.

Alzheimer's disease: Elevated pigment epithelium-derived factor in the cerebrospinal fluid is mostly of systemic origin.

Pigment-epithelium derived factor (PEDF) is a neurotrophic factor with neuroprotective, anti-tumorigenic, and anti-angiogenic effects. Elevated levels of PEDF have previously been proposed as a cerebrospinal fluid (CSF) biomarker for Alzheimer's disease. However, the origin of PEDF in CSF, i.e. whether it is derived from the brain or from the systemic circulation, and the specificity of this finding hitherto remained unclear. Here, we analyzed levels of PEDF in paired CSF and serum samples by ELISA in patients with Alzheimer's disease (AD, n=12), frontotemporal dementia (FTD, n=6), vascular dementia (n=4), bacterial meningitis (n=8), multiple sclerosis (n=32), pseudotumor cerebri (n=36), and diverse non-inflammatory neurological diseases (n=19). We established CSF/serum quotient diagrams to determine the fraction of intrathecally synthesized PEDF in CSF. We found that PEDF is significantly increased in CSF of patients with AD, FTD, and bacterial meningitis. Remarkably, PEDF concentrations were also significantly elevated in serum of patients with AD. CSF/serum quotient diagrams demonstrated that elevated PEDF concentrations in CSF of patients with AD are mostly due to elevated PEDF concentrations in serum. These findings underscore the importance of relating concentrations of proteins in CSF to their respective concentrations in serum to avoid erroneous interpretations of increased protein concentrations in lumbar CSF.

SFRP Tumour Suppressor Genes Are Potential Plasma-Based Epigenetic Biomarkers for Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is associated with asbestos exposure. Asbestos can induce chronic inflammation which in turn can lead to silencing of tumour suppressor genes. Wnt signaling pathway can be affected by chronic inflammation and is aberrantly activated in many cancers including colon and MPM. SFRP genes are antagonists of Wnt pathway, and SFRPs are potential tumour suppressors in colon, gastric, breast, ovarian, and lung cancers and mesothelioma. This study investigated the expression and DNA methylation of SFRP genes in MPM cells lines with and without demethylation treatment. Sixty-six patient FFPE samples were analysed and have showed methylation of SFRP2 (56%) and SFRP5 (70%) in MPM. SFRP2 and SFRP5 tumour-suppressive activity in eleven MPM lines was confirmed, and long-term asbestos exposure led to reduced expression of the SFRP1 and SFRP2 genes in the mesothelium (MeT-5A) via epigenetic alterations. Finally, DNA methylation of SFRPs is detectable in MPM patient plasma samples, with methylated SFRP2 and SFRP5 showing a tendency towards greater abundance in patients. These data suggested that SFRP genes have tumour-suppresive activity in MPM and that methylated DNA from SFRP gene promoters has the potential to serve as a biomarker for MPM patient plasma.

Association of Circulating Markers With Outcome Parameters in the Bevacizumab and Ranibizumab in Diabetic Macular Edema Trial.

Purpose: The purpose of this study was to evaluate selected candidate biomarkers as potential markers for patients with diabetic macular edema (DME) who receive antivascular endothelial growth factor (VEGF) therapy. Methods: Selected biomarkers included blood levels of messenger RNA (mRNA) of retinoschisin, RPE65, rhodopsin, and endothelial progenitor cell markers CD34 and CD133. Blood samples were obtained from 89 patients with DME according to the study protocol of the Bevacizumab and Ranibizumab in Diabetic Macular Edema (BRDME) study. During each monthly visit, patients underwent optical coherence tomography scanning and visual acuity was measured. Anti-VEGF injections were administered at fixed monthly intervals over 6 months. Analyses of covariance using simplified and linear mixed models were used to examine the correlations between candidate markers and changes in visual acuity and central subfield thickness. Results: Plasma mRNA levels of retinoschisin were negatively associated with visual acuity, and plasma mRNA levels of rhodopsin were positively associated with visual acuity in patients with DME (P < 0.01 and P < 0.05, respectively). In addition, changes in central subfield thickness between baseline and months 1, 2, and 3 during anti-VEGF treatment were associated with mRNA levels of retinoschisin, rhodopsin, and the ratio of retinoschisin-to-rhodopsin (P < 0.01, all). Conclusions: This prospective, multicenter study found that circulating mRNA levels of retinoschisin and rhodopsin are associated with visual acuity and changes in central subfield thickness during anti-VEGF therapy in patients with DME. (ClinicalTrials.gov number: NCT01635790.).

Pigment epithelium-derived factor and matrix metalloproteinase-9 in liver cirrhosis.

BACKGROUND/AIM: The aim of this study was to assess the role of serum pigment epithelium-derived factor (PEDF) and matrix metalloproteinase-9 (MMP-9) in progression of liver cirrhosis and development of hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Serum levels of PEDF and MMP-9 were tested in 212 patients with liver cirrhosis and in a control group of 30 healthy volunteers. HCC was diagnosed in 45 of the 212 patients studied (21%). RESULTS: Serum PEDF and MMP-9 were higher in the study group than that in the control group (P < 0.001). In patients with alcoholic or mixed (alcoholic and viral hepatitis-related) cirrhosis, serum PEDF was higher than that in other patients (13970.2 ± 13406.9 ng/ml vs. 8563.5 ± 9602.7 ng/ml, P = 0.008). In patients with viral hepatitis-related cirrhosis, significantly higher PEDF levels were recorded in those with HCC (13429.1 ± 12045.8) than that in patients without HCC (6660.1 ± 7927.1; P = 0.04). There was a trend for higher serum MMP-9 in patients with HCC (5778.7 ± 12426.6 vs. 1389.8 ± 1944.7 in those without HCC; P = 0.07). Significant negative correlation between serum MMP-9 and serum alpha-fetoprotein in patients with HCC was observed (r = -0.54; P = 0.04). CONCLUSION: Serum PEDF and MMP-9 could be auxiliary markers in diagnosis of HCC, especially in patients with low alpha-fetoprotein level. Alcohol consumption can affect serum PEDF.