Soluble urokinase plasminogen activator receptor (suPAR) in children with obesity or type 1 diabetes as a marker of endothelial dysfunction: a cross-sectional study

Pediatric obesity and type 1 diabetes mellitus (T1DM) represent two common chronic diseases associated with chronic inflammation, endothelial dysfunction and long-term complications. The aim of the present study was to assess the possible diagnostic and prognostic value of soluble urokinase plasminogen activator receptor (suPAR), a marker of inflammation and impaired endothelial function, in children with the diseases. In this cross-sectional study, children and adolescents with T1DM (N = 41) or obesity (N = 37), aged < 18 years old, and without proteinuria were included, together with children of similar age and without evident morbidity that served as controls (N = 42). Serum samples were obtained during standard outpatient follow up and the urokinase-type plasminogen activator receptor (suPAR) concentrations were measured using a commercially available sandwich ELISA kit (DUP00, R&D systems). Clinical and biochemical indices that were also assessed include body mass index (BMI) z-score, Tanner stages, glycosylated haemoglobin (HbA1c), fasting lipid profile and serum creatinine. Mean serum suPAR levels were significantly higher in patients with obesity compared to patients with T1DM and controls, while children with T1DM had similar suPAR levels to controls. Also, serum suPAR levels showed a negative correlation with age (Spearman rho -0.359, p < 0.001) and serum creatinine levels (Spearman rho -0.334, p = 0.005), and a positive correlation with BMI z-score (Spearman rho 0.354, p = 0.009) in the whole cohort.  Conclusion: Serum suPAR may be a useful predictive marker of inflammation or endothelial dysfunction for children with obesity and T1DM, as well as a promising therapeutic target. Further studies are needed in order to clarify whether the reported differences in suPAR levels could reflect a greater impairment of the inflammation status and endothelial function in children with obesity compared to children with T1DM. What is Known: • Paediatric obesity and type 1 diabetes are characterised by chronic inflammation and metabolic dysregulation. • Urokinase plasminogen activator receptor (uPAR) has been proposed as a useful biomarker for chronic inflammation and cardiovascular risk in adults. What is New: • Serum suPAR levels were increased in children and adolescents with obesity compared to those with T1DM and healthy controls; thus, obesity may affect the inflammatory status and endothelial function to a higher degree than T1DM during childhood. • Serum suPAR may serve as a diagnostic and predictive marker of inflammation and endothelial dysfunction for children and adolescents with obesity and T1DM.

Changes in the expression level of IL-17A and p53-fibrinolytic system in smokers with or without COPD

COPD is a chronic airway inflammatory disease characterized mainly by neutrophil airway infiltrations. The neutrophil airway inflammation is mainly mediated through a key player like the pro-inflammatory cytokine IL-17A which is involved in the modulation of p53-fibrinolytic system. This study was undertaken to examine the molecular changes for the expressions of IL-17A and p53-fibrinolytic system in smokers with or without COPD. Blood and serum samples were collected from ten patients of smokers having COPD and ten samples from smokers without COPD and ten healthy control subjects. Western blot analyses were performed to evaluate the expressions of IL-17A, p53 and PAI-1. Apoptosis was assessed by immunoblot for cleaved caspase-3. In addition, FEV% was also determined of these patients. qRT-PCR was done to detect the gene expression study from the blood samples on p53-fibrinolytic components. A significant difference was found in the expression levels of IL-17A in smokers with COPD patient when compared to smokers without COPD and the control subjects. Similarly the smokers with COPD showed significant increase in the fibrinolytic component PAI-1 as well as in expression levels of p53 when compared to smokers without COPD and normal subjects. Increased cleaved caspase-3 may also promote apoptosis.The expression pattern of the IL-17A in chronic obstructive pulmonary distress syndrome samples was increased as compared of those of normal samples, and their main role in the regulation of and p53-fibrinolytic system makes these components as a predictive prominent component in smokers with COPD.

Prognostic implications of the co-detection of the urokinase plasminogen activator system and osteopontin in patients with non-small-cell lung cancer undergoing radiotherapy and correlation with gross tumor volume

BACKGROUND

The urokinase plasminogen activator system (uPA, uPAR, PAI‑1) is upregulated in cancer and high plasma levels are associated with poor prognosis. Their interaction with hypoxia-related osteopontin (OPN) which is also overexpressed in malignant tumors suggests potential clinical relevance. However, the prognostic role of the uPA system in the radiotherapy (RT) of non-small-cell lung cancer (NSCLC), particularly in combination with OPN, has not been investigated so far.

METHODS

uPA, uPAR, PAI‑1 and OPN plasma levels of 81 patients with locally advanced or metastasized NSCLC were prospectively analyzed by ELISA before RT and were correlated to clinical patient/tumor data and prognosis after RT.

RESULTS

uPAR plasma levels were higher in M1; uPA and PAI‑1 levels were higher in M0 NSCLC patients. uPAR correlated with uPA (p < 0.001) which also correlated with PAI‑1 (p < 0.001). The prognostic impact of OPN plasma levels in the RT of NSCLC was previously reported by our group. PAI‑I plasma levels significantly impacted overall (OS) and progression-free survival (PFS). Low PAI‑1 levels were associated with a significantly reduced OS and PFS with a nearly 2‑fold increased risk of death (p = 0.029) and tumor progression (p = 0.029). In multivariate analysis, PAI‑1 levels remained an independent prognostic factor for OS and PFS with a 3‑fold increased risk of death (p = 0.001). If PAI‑1 plasma levels were combined with OPN or tumor volume, we found an additive prognostic impact on OS and PFS with a 2.5- to 3‑fold increased risk of death (p = 0.01).

CONCLUSION

Our results suggest that PAI-1 but not uPA and uPAR might add prognostic information in patients with advanced NSCLC undergoing RT. High pretreatment PAI-1 plasma levels were found predominantly in M0-stage patients and indicate a favorable prognosis as opposed to OPN where high plasma levels are associated with poor survival and metastasis. In combination, PAI-1 and OPN levels successfully predicted outcome and additively correlated with prognosis. These findings support the notion of an antidromic prognostic impact of OPN and PAI-1 plasma levels in the RT of advanced NSCLC.

Cleavage of the urokinase receptor (uPAR) on oral cancer cells: regulation by transforming growth factor - β1 (TGF-β1) and potential effects on migration and invasion

BACKGROUND

Urokinase plasminogen activator (uPA) receptor (uPAR) is up-regulated at the invasive tumour front of human oral squamous cell carcinoma (OSCC), indicating a role for uPAR in tumour progression. We previously observed elevated expression of uPAR at the tumour-stroma interface in a mouse model for OSCC, which was associated with increased proteolytic activity. The tumour microenvironment regulated uPAR expression, as well as its glycosylation and cleavage. Both full-length- and cleaved uPAR (uPAR (II-III)) are involved in highly regulated processes such as cell signalling, proliferation, migration, stem cell mobilization and invasion. The aim of the current study was to analyse tumour associated factors and their effect on uPAR cleavage, and the potential implications for cell proliferation, migration and invasion.

METHODS

Mouse uPAR was stably overexpressed in the mouse OSCC cell line AT84. The ratio of full-length versus cleaved uPAR as analysed by Western blotting and its regulation was assessed by addition of different protease inhibitors and transforming growth factor - β1 (TGF-β1). The role of uPAR cleavage in cell proliferation and migration was analysed using real-time cell analysis and invasion was assessed using the myoma invasion model.

RESULTS

We found that when uPAR was overexpressed a proportion of the receptor was cleaved, thus the cells presented both full-length uPAR and uPAR (II-III). Cleavage was mainly performed by serine proteases and urokinase plasminogen activator (uPA) in particular. When the OSCC cells were stimulated with TGF-β1, the production of the uPA inhibitor PAI-1 was increased, resulting in a reduction of uPAR cleavage. By inhibiting cleavage of uPAR, cell migration was reduced, and by inhibiting uPA activity, invasion was reduced. We could also show that medium containing soluble uPAR (suPAR), and cleaved soluble uPAR (suPAR (II-III)), induced migration in OSCC cells with low endogenous levels of uPAR.

CONCLUSIONS

These results show that soluble factors in the tumour microenvironment, such as TGF-β1, PAI-1 and uPA, can influence the ratio of full length and uPAR (II-III) and thereby potentially effect cell migration and invasion. Resolving how uPAR cleavage is controlled is therefore vital for understanding how OSCC progresses and potentially provides new targets for therapy.

Selecting Tumor-Specific Molecular Targets in Pancreatic Adenocarcinoma: Paving the Way for Image-Guided Pancreatic Surgery

PURPOSE

The purpose of this study was to identify suitable molecular targets for tumor-specific imaging of pancreatic adenocarcinoma.

PROCEDURES

The expression of eight potential imaging targets was assessed by the target selection criteria (TASC)-score and immunohistochemical analysis in normal pancreatic tissue (n = 9), pancreatic (n = 137), and periampullary (n = 28) adenocarcinoma.

RESULTS

Integrin αvβ6, carcinoembryonic antigen (CEA), epithelial growth factor receptor (EGFR), and urokinase plasminogen activator receptor (uPAR) showed a significantly higher (all p < 0.001) expression in pancreatic adenocarcinoma compared to normal pancreatic tissue and were confirmed by the TASC score as promising imaging targets. Furthermore, these biomarkers were expressed in respectively 88 %, 71 %, 69 %, and 67 % of the pancreatic adenocarcinoma patients.

CONCLUSIONS

The results of this study show that integrin αvβ6, CEA, EGFR, and uPAR are suitable targets for tumor-specific imaging of pancreatic adenocarcinoma.

Association between promoter region of the uPAR (rs344781) gene polymorphism in genetic susceptibility to migraine without aura in three Iranian hospitals

INTRODUCTION

Migraine is a chronic neurological disorder. Inflammation has a key role in migraine pathophysiology. Urokinase plasminogen activator receptor (uPAR) directly involves in inflammatory conditions by facilitating migration of inflammatory cells to different tissues. The aim of this study was to investigate whether uPAR rs344781, common genetic polymorphism in the uPAR promoter region, might be associated with migraine without aura susceptibility in an Iranian population.

METHODS

We enrolled 103 newly diagnosed patients with migraine and 100 healthy controls. Peripheral blood sample was used for DNA extraction and uPAR rs344781 gene polymorphism was determined. Patients filled HIT-6 as a tool to evaluate headache severity.

RESULTS

The genotype frequency of uPAR is significantly different between migraine patients and control subjects. Heterozygote genotype (AG) was statistically more frequent in the patients than the controls (P=0.001; OR=2.67, 95% CI=1.51-4.7). Also G allele was more frequent in the patients. Total HIT-6 score was not significantly different between heterozygote and homozygote patients (55.50±2.22 vs. 49.60±3.68 respectively, P=0.075).

CONCLUSION

In conclusion, our study showed a significant association between uPAR rs344781 gene promoter polymorphism and migraine without aura susceptibility but not with headache severity.