Altered Plasma Levels and Tissue Expression of Fibroblast Activation Protein Alpha in Giant Cell Arteritis.

OBJECTIVE: Giant cell arteritis (GCA) is characterized by granulomatous inflammation of the medium- and large-sized arteries accompanied by remodeling of the vessel wall. Fibroblast activation protein alpha (FAP) is a serine protease that promotes both inflammation and fibrosis. Here, we investigated the plasma levels and vascular expression of FAP in GCA. METHODS: Plasma FAP levels were measured with enzyme-linked immunosorbent assay in treatment-naive patients with GCA (n = 60) and polymyalgia rheumatica (PMR) (n = 63) compared with age- and sex-matched healthy controls (HCs) (n = 42) and during follow-up, including treatment-free remission (TFR). Inflamed temporal artery biopsies (TABs) of patients with GCA (n = 9), noninflamed TABs (n = 14), and aorta samples from GCA-related (n = 9) and atherosclerosis-related aneurysm (n = 11) were stained for FAP using immunohistochemistry. Immunofluorescence staining was performed for fibroblasts (CD90), macrophages (CD68/CD206/folate receptor beta), vascular smooth muscle cells (desmin), myofibroblasts (α-smooth muscle actin), interleukin-6 (IL-6), and matrix metalloproteinase-9 (MMP-9). RESULTS: Baseline plasma FAP levels were significantly lower in patients with GCA compared with patients with PMR and HCs and inversely correlated with systemic markers of inflammation and angiogenesis. FAP levels decreased even further at 3 months on remission in patients with GCA and gradually increased to the level of HCs in TFR. FAP expression was increased in inflamed TABs and aorta of patients with GCA compared with control tissues. FAP was abundantly expressed in fibroblasts and macrophages. Some of the FAP+ fibroblasts expressed IL-6 and MMP-9. CONCLUSION: FAP expression in GCA is clearly modulated both in plasma and in vessels. FAP may be involved in the inflammatory and remodeling processes in GCA and have utility as a target for imaging and therapeutic intervention.

Predictive value of cystatin C and neutrophil gelatinase-associated lipocalin in contrast-induced nephropathy: A meta-analysis.

BACKGROUND: There are still limited studies comprehensively examining the diagnostic performance of neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C in contrast-induced nephropathy (CIN). The study aimed to investigate and compare the predictive value of NGAL and cystatin C in the early diagnosis of CIN. METHODS AND MATERIALS: We searched the PubMed, EMBASE and Cochrane Library databases until November 10, 2019. The methodological quality of the included studies was assessed by the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Bivariate modeling and hierarchical summary receiver operating characteristic (HSROC) modeling were performed to summarize and compare the diagnostic performance of blood/urine NGAL and serum cystatin C in CIN. Subgroup and meta-regression analyses were performed according to the study and patient characteristics. RESULTS: Thirty-seven studies from thirty-one original studies were included (blood NGAL, 1840 patients in 9 studies; urine NGAL, 1701 patients in 10 studies; serum cystatin C, 5509 patients in 18 studies). Overall, serum cystatin C performed better than serum/urine NGAL (pooled DOR: 43 (95%CI: 12-152); AUROC: 0.93; λ: 3.79); serum and urine NGAL had a similar diagnostic performance (pooled DOR: 25 (95%CI: 6-108)/22(95%CI: 8-64); AUROC: 0.90/0.89; λ: 3.20/3.08). Meta-regression analysis indicated that the sources of heterogeneity might be CIN definition, assays, and nationalities. CONCLUSION: Both NGAL and cystatin C can serve as early diagnostic indicators of CIN, while cystatin C may perform better than NGAL.

Dysregulated activities of proline-specific enzymes in septic shock patients (sepsis-2).

The proline-specific enzymes dipeptidyl peptidase 4 (DPP4), prolylcarboxypeptidase (PRCP), fibroblast activation protein α (FAP) and prolyl oligopeptidase (PREP) are known for their involvement in the immune system and blood pressure regulation. Only very limited information is currently available on their enzymatic activity and possible involvement in patients with sepsis and septic-shock. The activity of the enzymes was measured in EDTA-plasma of patients admitted to the intensive care unit (ICU): 40 septic shock patients (sepsis-2) and 22 ICU control patients after major intracranial surgery. These data were used to generate receiver operating characteristic (ROC) curves. A survival analysis (at 90 days) and an association study with other parameters was performed. PRCP (day 1) and PREP (all days) enzymatic activities were higher in septic shock patients compared to controls. In contrast, FAP and DPP4 were lower in these patients on all studied time points. Since large differences were found, ROC curves were generated and these yielded area under the curve (AUC) values for PREP, FAP and DPP4 of 0.88 (CI: 0.80-0.96), 0.94 (CI: 0.89-0.99) and 0.86 (CI: 0.77-0.95), respectively. PRCP had a lower predicting value with an AUC of 0.71 (CI: 0.58-0.83). A nominally significant association was observed between survival and the DPP4 enzymatic activity at day 1 (p<0.05), with a higher DPP4 activity being associated with an increase in survival. All four enzymes were dysregulated in septic shock patients. DPP4, FAP and PREP are good in discriminating between septic shock patients and ICU controls and should be further explored to see whether they are already dysregulated in earlier stages, opening perspectives for their further investigation as biomarkers in sepsis. DPP4 also shows potential as a prognostic biomarker. Additionally, the associations found warrant further research.

Higher serum levels of fibroblast growth factor 21 in old patients with cachexia.

OBJECTIVE: Fibroblast growth factor (FGF)21 is promptly induced by short fasting in animal models to regulate glucose and fat metabolism. Data on FGF21 in humans are inconsistent and FGF21 has not yet been investigated in old patients with cachexia, a complex syndrome characterized by inflammation and weight loss. The aim of this study was to explore the association of FGF21 with cachexia in old patients compared with their healthy counterparts. METHODS: Serum FGF21 and its inactivating enzyme fibroblast activation protein (FAP)-α were measured with enzyme-linked immunoassays. Cachexia was defined as ≥5% weight loss in the previous 3 mo and concurrent anorexia (Council on Nutrition appetite questionnaire). RESULTS: We included 103 patients with and without cachexia (76.9 ± 5.2 y of age) and 56 healthy controls (72.9 ± 5.9 y of age). Cachexia was present in 16.5% of patients. These patients had significantly higher total FGF21 levels than controls (952.1 ± 821.3 versus 525.2 ± 560.3 pg/mL; P = 0.012) and the lowest FGF21 levels (293.3 ± 150.9 pg/mL) were found in the control group (global P < 0.001). Although FAP-α did not differ between the three groups (global P = 0.082), bioactive FGF21 was significantly higher in patients with cachexia (global P = 0.002). Risk factor-adjusted regression analyses revealed a significant association between cachexia and total (ß = 649.745 pg/mL; P < 0.001) and bioactive FGF21 (ß = 393.200 pg/mL; P <0.001), independent of sex, age, and body mass index. CONCLUSIONS: Patients with cachexia exhibited the highest FGF21 levels. Clarification is needed to determine whether this is an adaptive response to nutrient deprivation in disease-related cachexia or whether the increased FGF21 values contribute to the catabolic state.

The development and validation of a combined kinetic fluorometric activity assay for fibroblast activation protein alpha and prolyl oligopeptidase in plasma.

BACKGROUND: Fibroblast activiation protein alpha (FAP) is considered a diagnostic and prognostic biomarker for various types of cancer. FAP shares substrate specificity with prolyl oligopeptidase (PREP), studied in (neuro)inflammation and neurodegeneration as well as cancer. Current assays inadequately discriminate between FAP and PREP and there is need for an assay that reliably quantitates the FAP/PREP activity ratio in plasma. METHODS: FAP and PREP activities were measured in human EDTA-plasma in presence of well characterized PREP and FAP inhibitors. RESULTS: A combined kinetic assay was developed in conditions to optimally measure FAP as well as PREP activity with Z-Gly-Pro-AMC as substrate. Limit of detection was 0.009 U/L and limit of quantitation was 0.027 U/L for the combined FAP-PREP assay. Within-run coefficient of variation was 3% and 4% and between-run precision was 7% and 12% for PREP and FAP, respectively. Accuracy was demonstrated by comparison with established end-point assays. Hemolysis interferes with the assay with 1.5 g/L hemoglobin as cut-off value. PREP (but not FAP) activity can increase upon lysis of platelets and red blood cells during sample preparation. CONCLUSION: With this new assay, on average 67% of the Z-Gly-Pro-AMC converting activity in plasma can be attributed to FAP.

A novel strategy for identifying early acute kidney injury in pediatric hematopoietic stem cell transplantation.

Acute kidney injury (AKI) is a common complication in pediatric hematopoietic stem cell transplantation (HSCT). Serum creatinine is an imprecise biomarker of AKI. We hypothesized that combining creatinine with serum cystatin C (cysC) and urinary neutrophil gelatinase-associated lipocalin (NGAL) more effectively characterizes AKI during the first 28 days of HSCT and better identifies patients at risk of adverse outcomes than creatinine alone. We prospectively assessed the type and severity of AKI in 80 consecutive allogeneic HSCT patients using weekly creatinine, cysC, and NGAL. We combined the biomarkers to define 7 Composite Types of AKI, including All Positive AKI (simultaneously detected creatinine, cysC, and NGAL AKI). Outcomes included renal replacement therapy and transplant-related mortality. In all, 75% of patients had AKI by at least one measure; 33% developed >1 type of AKI. Mild AKI often preceded Severe AKI. Patients with creatinine or NGAL AKI that were Severe or Repeated tended to have worse outcomes. The five patients with All Positive AKI had the highest rates of morbidity and mortality. AKI evaluation with creatinine, cysC, and NGAL provides a comprehensive profile of early AKI and narrowly identifies patients at highest risk of adverse outcomes, providing opportunities for early, impactful intervention.

Afterglow Resonance Energy Transfer Inhibition for Fibroblast Activation Protein-α Assay.

Traditional photoluminescence resonance energy transfer (PRET)-based sensors are widely applied, but still suffer from the severe background interference from in situ excitation. The afterglow nature of the persistent luminescence nanoparticles (PLNPs) allows optosensing after the stoppage of in situ illumination, and thus subtly overcomes that interference. We proposed a simple strategy for functionalizing PLNPs for bioanalytical applications and the new afterglow resonance energy transfer (ARET)-based assay for quantitative determination and imaging of fibroblast activation protein-alpha (FAPα) in live cells using Au-decorated Cr3+0.004:ZnGa2O4 as donor and Cy5.5-KGPNQC-SH as acceptor. The ARET between the donor and acceptor quenches the afterglow of the donor, and the cleavage of peptide KGPNQC by FAPα inhibits the ARET and restores the afterglow of the donor. The ARET-based assay of FAPα, with the linear range of 0.1-2.0 mg·L-1 (1.2-22.9 nM), LOD of 11 µg·L-1 (115 pM), and RSD of 3.9% (for 0.5 mg·L-1 FAPα, n = 5), displays higher sensitivity, lower limit of detection (LOD), and better anti-interference capability than the corresponding PRET-based assay. Besides, the ARET-based sensors are lighted up by the FAPα-positive U87MG and MDA-MB-435 cells, but kept in the dark when incubated in the FAPα-negative AD293 cells. The proposed ARET-based sensor can detect FAPα of U87MG and MDA-MB-435 living cells in human serum with the spiked recoveries of 95.6-103%. Our data demonstrated a simple and effective strategy for bridging PLNPs to bioanalytical applications, and an attractive ARET assay of FAPα.

Eccentric exercise increases circulating fibroblast activation protein α but not bioactive fibroblast growth factor 21 in healthy humans.

NEW FINDINGS: What is the central question of this study? The role of FGF21 as an exercise-induced myokine remains controversial. The aim of this study was to determine whether eccentric exercise would augment the release of FGF21 and/or its regulatory enzyme, fibroblast activation protein α (FAP), from skeletal muscle tissue into the systemic circulation of healthy human volunteers. What is the main finding and its importance? Eccentric exercise does not release total or bioactive FGF21 from human skeletal muscle. However, exercise releases its regulatory enzyme, FAP, from tissue(s) other than muscle, which might play a role in the inactivation of FGF21. ABSTRACT: The primary aim of the investigation was to determine whether eccentric exercise would augment the release of the myokine fibroblast growth factor 21 (FGF21) and/or its regulatory enzyme, fibroblast activation protein α (FAP), from skeletal muscle tissue into the systemic circulation of healthy human volunteers. Physically active young healthy male volunteers (age 25.0 ± 10.7 years; body mass index 23.1 ± 7.9 kg m-2 ) completed three sets of 25 repetitions (with 5 min rest in between) of single-leg maximal eccentric contractions using their non-dominant leg, whilst the dominant leg served as a control. Arterialized blood samples from a hand vein and deep venous blood samples from the common femoral vein of the exercised leg, along with blood flow of the superficial femoral artery using Doppler ultrasound, were obtained before and after each exercise bout and every 20 min during the 3 h recovery period. Muscle biopsy samples were taken at baseline, immediately and 3 and 48 h postexercise. The main findings showed that there was no significant increase in total or bioactive FGF21 secreted from skeletal muscle into the systemic circulation in response to exercise. Furthermore, skeletal muscle FGF21 protein content was unchanged in response to exercise. However, there was a significant increase in arterialized and venous FAP concentrations, with no apparent contribution to its release from the exercised leg. These findings raise the possibility that the elevated levels of FAP might play a role in the inactivation of FGF21 during exercise.

Circulating gelatinases are not prognostic of treatment response and survival in locally advanced rectal cancer patients undergoing preoperative chemoradiotherapy.

PURPOSE: To investigate whether the serum levels of matrix metalloproteinases (MMPs) are predictive on treatment response and survival in locally advanced rectal cancer (LARC) patients undergoing preoperative chemoradiotherapy. PATIENTS AND METHODS: Serum MMP-2 and MMP-9 was analyzed by enzyme-linked immunosorbent assay and obtained before, midway, and 1-month after the end of preoperative radiotherapy treatment. The prognostic significance of serum MMP-2 and MMP-9 levels and their association with other pathological findings for LARC patients were evaluated. RESULTS: Serum levels of MMP-2 or MMP-9 were found to decrease with increasing clinical stage and negative correlation was statistically significant (P < 0.05). There was no statistically significant difference in tumor response and survival between the low and high MMP-2 and MMP-9 groups. MMP-2 and MMP-9 were not correlated with local-regional recurrence. CONCLUSIONS: We propose that serum levels of MMP-2 and MMP-9 are not predictive on treatment response and survival in LARC patients.

Circulating fibroblast activation protein and dipeptidyl peptidase 4 in rheumatoid arthritis and systemic sclerosis.

AIM: To quantify circulating fibroblast activation protein (cFAP) and dipeptidyl peptidase 4 (cDPP4) protease activities in patients with rheumatoid arthritis (RA), systemic sclerosis (SSc), and a control group with mechanical back pain and to correlate plasma levels with disease characteristics. METHODS: Plasma was collected from patients with RA (n = 73), SSc (n = 37) and control subjects (n = 26). DPP4 and FAP were quantified using specific enzyme activity assays. RESULTS: Median cDPP4 was significantly lower in the RA group (P = 0.02), and SSc group (P = 0.002) compared with controls. There were no significant differences in median cFAP between the three groups. DPP4 and FAP demonstrated a negative correlation with inflammatory markers and duration of disease. There were no associations with disease subtypes in RA, including seropositive and erosive disease. Decreased cDPP4 was found in SSc patients with myositis. Plasma FAP was lower in RA patients receiving prednisone (P = 0.001) or leflunomide (P = 0.04), but higher with biologic agents (P = 0.01). RA patients receiving leflunomide also had decreased cDPP4 (P = 0.014). SSc patients receiving prednisone (P = 0.02) had lower cDPP4 but there was no association with cFAP. CONCLUSIONS: No association was found between cFAP and RA or SSc. Plasma DPP4 was decreased in RA and SSc when compared with controls. cDPP4 and cFAP correlated negatively with inflammatory markers and there were no significant correlations with disease characteristics in this RA cohort.

[Biomarkers of renal injury in contact ureteral lithotripsy].

AIM: To optimize the transurethral endoscopic management of patients with ureterolithiasis by measuring biomarkers of renal parenchymal damage. MATERIALS AND METHODS: One hundred fifty-one patients with solitary ureteral stones were tested for levels of cystatin C, neutrophil gelatinase-associated lipocalin, 2-microglobulin and interleukin 18. RESULTS: An increase in the levels of markers of renal injury was observed both in the preoperative period and after CULT. Differences in the values of these indices depended on the timing of the CULT, the size and location of the stone and the type of lithotripter. CONCLUSIONS: All patients were found to have damage to the renal tubular system. The established critical values of the markers of renal injury in ureterolithiasis may be used as diagnostic criteria for renal injury.

Evaluation of the circulating level of fibroblast activation protein α for diagnosis of esophageal squamous cell carcinoma.

To evaluate whether circulating fibroblast activation protein α (FAPα) could serve as a biomarker for the diagnosis of esophageal squamous cell carcinoma (ESCC), enzyme-linked immunosorbent assay (ELISA) was used to detect plasma FAPα in 556 participants including ESCC group, benign esophageal disease group, healthy controls and other cancer controls group. The levels of plasma FAPα were significantly decreased in ESCC patients (P < 0.001) and showed a positive correlation with HDL-C levels (R = 0.372, P < 0.001). The sensitivity and specificity of plasma FAPα were 56.1% and 85.6% based on the optimal cut-off (49.04 ng/ml, AUC = 0.714). The combination of FAPα and the traditional biomarkers (CEA, CYFR211 and SCCA) improved the sensitivity (41.5%) without compromising the specificity (95.0%). Contradictorily, the immunohistochemical staining revealed the overexpression of FAPα in stroma of ESCC tissues. So the source of soluble FAPα was further explored by qRT-PCR, Western blotting, ELISA and immunoprecipitation in fibroblast cell lines and mouse xenograft models. We found that the plasma FAPα was not correlated with the FAPα expressed in tumor, and the multi-organ might contribute to the circulating levels of FAPα including skeletal muscle, liver and bone marrow. These results indicated that the low plasma FAPα level might due to the systemic reaction to the presence of tumor and circulating FAPα level might be a potential indicator for diagnosing ESCC.

Acute Ischemic Stroke Severity, Progression, and Outcome Relate to Changes in Dipeptidyl Peptidase IV and Fibroblast Activation Protein Activity.

Dipeptidyl peptidase IV (DPPIV) inhibition may be a promising therapeutic strategy for acute stroke treatment, given its potential to prolong the biological half-life of neuroprotective substrates. A related protease, fibroblast activation protein (FAP), was recently shown to inactivate the same substrates. Therefore, it should also be investigated as a potential target in stroke. The study aimed to investigate whether stroke severity and outcome correlate with DPPIV and FAP activities and their kinetics shortly after acute ischemic stroke. DPPIV and FAP activities were analyzed in the serum of 50 hyperacute stroke patients at admission, 1 day, 3 days, and 7 days after stroke onset and in 50 age-matched healthy controls. This was done as part of the Middelheim's Interdisciplinary Stroke Study. DPPIV activity tended to increase shortly after stroke compared to the control population. DPPIV and FAP activities steadily decreased in the first week after stroke onset. Higher infarct volumes (≥5 ml) and a more severe stroke (NIHSS >7) at admission were correlated with a stronger decrease in the activities of both enzymes. Moreover, these patients more often developed a progressive stroke, were more often institutionalized. Patients with a stronger increase in DPPIV activity at admission and decrease in the activity of both DPPIV and FAP during the first week after stroke onset had a more severe stroke and worse short-term outcomes.

Differential Diagnosis of Autoimmune Pancreatitis From Pancreatic Cancer by Analysis of Serum Gelatinase Levels.

OBJECTIVES: The aim of this study was to analyze serum gelatinases as part of the clinical strategy for the preoperative differentiation between autoimmune pancreatitis (AIP) and pancreatic ductal adenocarcinoma (PDAC). The finding of differential markers will prevent unnecessary surgical resection and allow optimal treatment of these diseases. METHODS: Quantitative gelatin zymography was applied to analyze all individual gelatinase forms in serum and to define proteinase alterations associated with AIP and PDAC. For this purpose, sera of 130 patients, being 29 with AIP, 33 with chronic pancreatitis, 32 with PDAC, and 36 healthy controls, were first assayed for gelatinase levels by quantitative zymography before further validation by the analysis with commercial sandwich enzyme linked immunosorbent assays. RESULTS: Serum profiling data obtained by zymography analysis revealed that gelatinase B/matrix metalloproteinase 9 (MMP-9), the neutrophil gelatinase B-associated lipocalin/MMP-9 complex, and gelatinase A/MMP-2 levels were significantly increased in patients with AIP. These proteins are promising markers to discriminate between AIP and PDAC. The best composite parameter, being the ratio of total MMP-9 over MMP-2 levels, can predict 93% of the AIP and 75% of the PDAC correctly. With enzyme linked immunosorbent assay, we confirmed the zymography results. CONCLUSIONS: Differential gelatinase serum profiles as AIP markers, together with other clinical tests, help to assure the diagnosis of PDAC or AIP.

Lower serum fibroblast activation protein shows promise in the exclusion of clinically significant liver fibrosis due to non-alcoholic fatty liver disease in diabetes and obesity.

UNLABELLED: Non-alcoholic fatty liver disease (NAFLD) is common in diabetes and obesity but few have clinically significant liver fibrosis. Improved risk-assessment is needed as the commonly used clinical-risk algorithm, the NAFLD fibrosis score (NFS), is often inconclusive. AIMS: To determine whether circulating fibroblast activation protein (cFAP), which is elevated in cirrhosis, has value in excluding significant fibrosis, particularly combined with NFS. METHODS: cFAP was measured in 106 with type 2 diabetes who had transient elastography (Cohort 1) and 146 with morbid obesity who had liver biopsy (Cohort 2). RESULTS: In Cohort 1, cFAP (per SD) independently associated with median liver stiffness (LSM) ≥ 10.3 kPa with OR of 2.0 (95% CI 1.2-3.4), p=0.006. There was 0.12 OR (95% CI 0.03-0.61) of LSM ≥ 10.3 kPa for those in the lowest compared with the highest FAP tertile (p=0.010). FAP levels below 730 pmol AMC/min/mL had 95% NPV for LSM ≥ 10.3 kPa and reclassified 41% of 64 subjects from NFS 'indeterminate-risk' to 'low-risk'. In Cohort 2, cFAP (per SD), associated with 1.7 fold (95% CI 1.1-2.8) increased odds of significant fibrosis (F ≥ 2), p=0.021, and low cFAP reclassified 49% of 73 subjects from 'indeterminate-risk' to 'low-risk'. CONCLUSIONS: Lower cFAP, when combined with NFS, may have clinical utility in excluding significant fibrosis in diabetes and obesity.

Redox-regulation of gelatinases during growth of cisplatin-sensitive and resistant Guerin carcinoma.

UNLABELLED: Study was aimed to analyze the dynamics of changes and study interrelations between content of ferritin, transferrin, active gelatinases (MMP-2 and -9) in blood serum and tumor tissue, free iron, rate of superoxide radicals generation in tumor, activity of NADPH-oxidase and iNOS in neutrophils rats with sensitive and resistant strains of Guerin carcinoma (GC). MATERIALS AND METHODS: In order to obtain resistant tumor, 12 courses of cisplatin chemotherapy have been carried out on rats bearing GC. Levels of transferrin and free iron were determined by analysis of EPR spectra from computerized radiospectrometer EPR -RE-1307 at temperature of liquid nitrogen. Rate of superoxide radicals and nitric oxide generation in tumor and neutrophils of blood was determined by EPR using spin traps at room temperature. Content of ferritin in tumor homogenate and blood serum of rats with GC was determined by ELISA method using corresponding kits. Concentration of active forms of MMP-2 and -9 in obtained samples was determined using method of zymography. RESULTS: Unregulated generation of superoxide radicals and NO by mitochondria of tumor cells and NADPH-oxidase and iNOS neutrophils via oxidation of iron-containing proteins causes the accumulation of "free iron" complexes in blood and tumor tissue of rats able to evoke oxide-induced damages of macromolecules. It has been shown that for resistant strain of carcinoma, as compared with sensitive one, significantly higher concentrations of active forms of MMP-2 and -9 in blood serum of rats are typical. Dynamics of gelatinases activity changes in tumor tissue corresponds in general with dynamics of changes in serum. In tumor tissue of rats the indices of gelatinases activity positively correlate with rate of superoxide radicals generation, content of "free iron" complexes, ferritin and activity of transferrin. Cytostatic agent increased levels of reactive oxygen species (ROS) and self-amplify rate of superoxide radicals generation. In turn, activation of MMPs via superoxide-depending regulation allows tumor cells to facilitate migration, invasion and finally - formation of metastatic centers. Mentioned above tumor "oxide phenotype" determines high level of its aggressiveness and forms corresponding level of drug resistance. CONCLUSIONS: Thus, high levels of superoxide radicals oxidize transport proteins and form free iron pool. Iron ions, via Haber - Weiss mechanism, initiate generation of the hydroxyl radicals, which also enhance oxidation processes.

Serum and tissue expression of gelatinase and Twist in breast cancer.

OBJECTIVE: This study aimed to investigate the levels of matrix metalloproteinases (MMP)-2, MMP-9 and Twist in tumor tissue and serum from 46 cases of breast cancer patients and 31 cases of benign breast diseases patients by immunohistochemical staining and enzyme-linked immunosorbent assay, respectively. The association of gelatinase and Twist expression with clinicopathological factors was also analyzed in the present study. PATIENTS AND METHODS: The studied population consisted of 46 breast cancer patients and 31 benign breast disease patients. Serum concentrations of MMP-2, MMP-9 and Twist were measured by using human enzyme-linked immunosorbent assay. The protein expression of Twist, MMP-2 and MMP-9 were determined by immunohistochemical. RESULTS: The results show that the levels of MMP-2, MMP-9 and Twist expression were significantly increased in tissue and serum from breast cancer group, compared to the group of benign breast lesions diseases (p < 0.05). The pre-operative serum levels of MMP-2, MMP-9 and Twist were positively correlated with their expression in breast cancer tissues, respectively (p < 0.05). We, then, correlated serum and tissue levels of MMP-2, MMP-9 and Twist in breast cancer samples with patients' clinicopathologic characteristics. Compared to low expression, high serum and tissue levels of MMP-2 and Twist were associated with lymph node metastasis and higher TNM stage, high tissue MMP-9 levels were associated with lymph node metastasis and higher TNM stage, and high serum MMP-9 levels were associated with c-erbB-2 expression. CONCLUSIONS: These data suggest that serum levels of MMP-2, MMP-9 and Twist could be as potential biomarkers for diagnosis and predicting metastasis of breast cancer.

Circulating concentrations of fibroblast activation protein α in apparently healthy individuals and patients with acute coronary syndrome as assessed by sandwich ELISA.

BACKGROUND: Fibroblast activation protein α (FAP) is a membrane glycoprotein with dipeptidyl-peptidase and collagenase activity and is expressed in cancer, arthritis, and atherosclerotic plaques. We hypothesized that FAP can be measured quantitatively in the circulation and provide prognostic information in acute coronary syndrome (ACS). METHODS: We assessed the performance of a commercially available FAP ELISA and the pre-analytic characteristics of the marker. We determined FAP concentrations in EDTA plasma samples from 101 apparently healthy blood donors and 407 patients with ACS. Patients were followed for 12 months regarding all-cause mortality and non-fatal myocardial infarction (MI). RESULTS: FAP was stable at room temperature (for 1 day) and 4°C (3 days) and resistant to 3 freeze/thaw cycles. Recovery of recombinant human FAP ranged from 78 to 103% and serial dilutions of spiked samples resulted in measurements within 91 to 120% of expected values. Patients with ACS had lower plasma FAP concentrations compared with blood donors [median (25th-75th percentiles): 84 (69-101) ng/mL vs. 108 (87-124) ng/mL, P < 0.001]. Patients presenting with FAP concentrations in the first quartile had a 3.0-fold higher risk of death (95% confidence interval 1.4-6.2) compared with patients in the second to fourth quartiles (P = 0.004). FAP concentration was not related to the risk of MI. CONCLUSIONS: Our study is the first to associate FAP with prognosis in ACS. The favorable pre-analytic characteristics of FAP will facilitate future studies of the marker in other disease settings associated with altered FAP expression.

Gender dimorphic increase in RBP-4 and NGAL in children born after IVF: an epigenetic phenomenon?

BACKGROUND: In vitro fertilisation (IVF) has been widely used during the last decades. Recent studies demonstrated some alterations in IVF children's metabolic profile compared with controls. The recently reported lipocalins retinol-binding protein 4 (RBP-4) and neutrophil gelatinase-associated lipocalin (NGAL), as well as visfatin, which are associated with glucose intolerance and could help in the early detection of metabolic abnormalities, have not been studied in IVF children as yet. We studied the lipocalins RBP-4 and NGAL as well as visfatin in children born after IVF. SUBJECTS AND METHODS: A total of 100 children born after IVF (47 boys) and 60 controls born after normal conception (30 boys), aged 4-14 year, were studied cross-sectionally. All children had a physical examination, their fasting glucose, insulin, lipid profile, RBP-4, NGAL, and visfatin were determined and their homoeostasis model assessment (HOMA) index was calculated. RESULTS: Children born after IVF had significantly higher RBP-4 (P = 0·009) and NGAL (P = 0·028) levels than controls. When divided by gender, RBP-4 remained higher in IVF girls (P = 0·002), whereas NGAL was higher in IVF boys (P = 0·021). Linear regression analysis had revealed that the differences are attributed to the IVF procedure per se. CONCLUSIONS: In our study, IVF children had significantly higher RBP-4 and NGAL levels than controls, suggesting early metabolic derangements that could be attributed to an epigenetic phenomenon. These results are in accordance with our earlier findings of higher blood pressure and triglycerides in IVF children than controls. Further prospective studies in IVF children will determine the natural course of their metabolic profile.

Can neutrophil gelatinase-associated lipocalin help depict early contrast material-induced nephropathy?

PURPOSE: To evaluate the utility of serum and urinary neutrophil gelatinase-associated lipocalin (NGAL) in depicting an event of contrast material-induced nephropathy (CIN) in patients who received iodinated contrast media, gadoterate meglumine, or radiopharmaceutical technetium-99m ((99m)Tc) and to evaluate the protective effect exerted by isotonic saline infusion, sodium bicarbonate administration, or N-acetylcysteine administration. MATERIALS AND METHODS: Institutional ethics committee approval was given, and informed consent was obtained. One hundred twenty patients were enrolled in a prospective study and divided into three groups: iomeprol group, magnetic resonance (MR) imaging group (gadoterate meglumine), and renal scintigraphy group ((99m)Tc). They randomly received N-acetylcysteine, physiologic saline, or sodium bicarbonate. Receiver operating characteristic (ROC) analysis, Kaplan-Meier curves, and Cox proportional hazard regression analysis were used. RESULTS: In the MR imaging and renal scintigraphy groups, there were significant changes in serum creatinine and NGAL levels, and there were no cases of CIN. In the iomeprol group, an early rise in NGAL was found, while serum creatinine level changes occurred 24 hours after contrast material administration. At ROC analysis, NGAL showed high sensitivity and specificity (serum NGAL: area under the curve, 0.995; 95% confidence interval [CI]: 0.868, 0.992; urinary NGAL: area under the curve, 0.992; 95% CI: 0.925, 1.000) in identifying CIN 8 hours after iomeprol administration. Regression analysis showed that NGAL independently predicted CIN. Administration of N-acetylcysteine, sodium bicarbonate, or physiologic saline did not influence NGAL level. CONCLUSION: NGAL depicted CIN in patients who received iodinated contrast material within 8 hours of contrast material administration. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120578/-/DC1.