Neutrophil Gelatinase-associated Lipocalin Complex Research Articles

Upregulation of Myocardial Neutrophil Gelatinase-Associated Lipocalin during Development of Heart Failure Caused by Volume-Overload and the Effect in Regulating Activity of Matrix Metalloproteinase-9.

In patients with heart failure (HF), circulating neutrophil gelatinase-associated lipocalin (NGAL) level is increased, which is considered to be a predictor of mortality or renal outcomes. The expression of NGAL in the heart and kidney and its role in HF remain unclear. Aortocaval fistula was created in rats as a model of volume overload (VO)-induced HF. During the development of HF, NGAL expression was upregulated in the heart but not in the kidney at both transcriptional and translational levels in the compensatory and HF phases, with a similar level in both phases. Cardiomyocytes were identified as the cell type responsible for NGAL expression. Consistent with the myocardial NGAL expression pattern, the plasma NGAL level was increased in both phases, and the level was not significantly different between both phases. We demonstrated the presence of a matrix metalloproteinase (MMP)-9/NGAL complex in cultured medium of cardiomyocytes isolated from volume-overloaded hearts by gelatin zymography. Formation of MMP-9/NGAL complex was shown to enhance the enzymatic activity of MMP-9. We found that early growth response (Egr)-1 was upregulated in the heart in both compensatory and HF phases. In neonatal cardiomyocytes, Egr-1 overexpression induced the gene expression of NGAL, which was dose-dependently suppressed by an interleukin-1 receptor antagonist. During the development of HF due to VO, NGAL was upregulated in the heart but not in the kidney in both compensatory and HF phases, with a similar expression level. Myocardial NGAL upregulation enhanced MMP-9 activity through formation of the MMP-9/NGAL complex. The expression of myocardial NGAL was regulated by Egr-1.

Up-regulation of matrix metalloproteinases-9 in the kidneys of diabetic rats and the association with neutrophil gelatinase-associated lipocalin

BackgroundMatrix metalloproteinases-9 (MMP-9) can regulate extracellular matrix deposition in diabetic glomerular injury. However, it remains unknown whether MMP-9 is involved in the renal tubular injury. Meanwhile, neutrophil gelatinase-associated lipocalin (NGAL), defined as a biomarker of proximal tubular injury, may influence MMP-9 by forming the MMP-9/NGAL complex. The aim of this study was to investigate MMP-9 expression in proximal renal tubules and the relationship of MMP-9 and NGAL in diabetic rat model treated with Valsartan.MethodsSprague Dawley rats were randomly divided into three groups: Diabetic group, Control group, and Treated group. The diabetic rat model was established by injection of streptozotocin. Related indexes were measured at the end of the 2nd, 4th, 8th and 12th week post-modeling.ResultsIn diabetic groups, the concentrations of MMP-9 markedly increased in the serum and urine of rats in the early stage, even before the appearance of pathological albuminuria. Markedly elevated MMP-9/NGAL complex concentrations were also tested in diabetic groups. Western blot and qPCR tests confirmed that MMP-9 expression levels in the proximal renal tubular epithelial cells of diabetic rats were significantly higher than in control groups (P < 0.05). Correlation analysis showed that MMP-9 was positively correlated with NGAL at both protein and gene expression levels. In addition, Valsartan observably reduced tubular injury as well as MMP-9 expression in diabetic rats.ConclusionsIn diabetic kidney injury, the expression of MMP-9 in the proximal renal tubular epithelial cells was significantly increased. Besides, a positive correlation was found between MMP-9 and NGAL expression, along with high levels of MMP-9/NGAL complex, which indicated that NGAL might participate in the regulation of MMP-9 expression. The administration of Valsartan may reduce this effect.

Urinary NGAL Measured after the First Year Post Kidney Transplantation Predicts Changes in Glomerular Filtration over One-Year Follow-Up.

Currently, serum creatinine and estimated glomerular filtration rate (eGFR) together with albuminuria or proteinuria are laboratory markers used in long-term monitoring of kidney transplant recipients. There is a need for more sensitive markers that could serve as early warning signs of graft dysfunction. Our aim was to assess the urinary concentrations of neutrophil gelatinase-associated lipocalin (NGAL) as a predictor of changes in kidney transplant function after the first year post-transplantation. We prospectively recruited 109 patients with functioning graft at least one year after the transplantation, with no acute conditions over the past three months, during their control visits in kidney transplant ambulatory. Urinary NGAL measured on recruitment was twice higher in patients with at least 10% decrease in eGFR over 1-year follow-up compared to those with stable or improving transplant function. Baseline NGAL significantly predicted the relative and absolute changes in eGFR and the mean eGFR during the follow-up independently of baseline eGFR and albuminuria. Moreover, baseline NGAL significantly predicted urinary tract infections during the follow-up, although the infections were not associated with decreasing eGFR. Additionally, we assessed urinary concentrations of matrix metalloproteinase 9—NGAL complex in a subgroup of 77 patients and found higher levels in patients who developed urinary tract infections during the follow-up but not in those with decreasing eGFR. High urinary NGAL in clinically stable kidney transplant recipients beyond the first year after transplantation may be interpreted as a warning and trigger the search for transient or chronic causes of graft dysfunction, or urinary tract infection.

Determination of FABP4, RBP4 and the MMP-9/NGAL complex in the serum of women with breast cancer.

Breast cancer is the most common type of cancer in females and is the leading cause of cancer-associated death among women, worldwide. The present study aimed to measure the serum levels of fatty acid-binding protein 4 (FABP4), retinol binding protein 4 (RBP4) and the MMP-9/neutrophil gelatinase-associated lipocalin (NGAL) complex in women diagnosed with breast cancer. Serum levels of the examined proteins were determined in the peripheral blood of patients via ELISA. Furthermore, whether the concentration of each protein was associated with breast cancer growth, molecular subtype, BMI, postmenopausal status, diabetes and the social background of patients was assessed. Women with invasive breast cancer demonstrated significantly higher levels of FABP4 (P=0.008). Additionally, considerably elevated FABP4 levels were demonstrated specifically in Luminal breast cancer cases (P<0.01). No significant association was recorded between RBP4 and breast cancer development. In addition, significantly lower levels of the MMP-9/NGAL complex were recorded in triple negative/HER-2 cases (P<0.05). BMI values appeared to influence the aforementioned associations, while significantly high serum levels of FABP4 and the MMP-9/NGAL complex were found in postmenopausal patients with breast cancer and a BMI ≥25 kg/m2 (P<0.05). In addition, high levels of FABP4 were significantly associated with breast cancer patients with diabetes (P=0.05). However, no association was identified between RBP4, the MMP-9/NGAL complex and diabetes. In conclusion, FABP4 can be regarded as a biomarker of breast cancer growth, while both FABP4 and the MMP-9/NGAL complex may provide considerable information regarding the development of specific breast cancer subtypes. FABP4 and the MMP-9/NGAL complex may also be able to predict the development of breast cancer in postmenopausal patients with obesity.

Association of Longitudinal Changes in Symptoms and Urinary Biomarkers in Patients with Urological Chronic Pelvic Pain Syndrome: A MAPP Research Network Study.

We analyzed a series of novel noninvasive urinary biomarkers for their ability to objectively monitor the longitudinal clinical status of patients with urological chronic pelvic pain syndrome. Baseline, 6 and 12-month urine samples were collected (216) and used to quantify vascular endothelial growth factor, vascular endothelial growth factor (VEGF) receptor 1 (R1), neutrophil gelatinase associated lipocalin (NGAL), matrix metalloproteinase-2, matrix metalloproteinase (MMP)-9, and MMP-9/NGAL complex by enzyme-linked immunosorbent assays. Patient symptom changes were classified as improved, stable or worse using a functional clustering algorithm. Proportional odds models were used to evaluate the association between symptom change and urinary biomarkers. Across all sampled participants, longitudinal decreases in normalized VEGF concentration (pg/μg) were associated with pain severity improvement, and decreases in MMP-9, NGAL and VEGF-R1 concentration (pg/ml) as well as NGAL normalized concentration were associated with improved urinary symptoms. Longitudinal decreases in normalized VEGF-R1 were associated with pain improvement in patients with moderate widespreadness, no bladder symptoms and no painful filling. Lower baseline normalized VEGF-R1 concentration was associated with pain improvement in patients with pelvic pain only. Higher baseline MMP-9/NGAL levels were associated with pain and urinary improvement across all participants. Moreover, longitudinal increases in MMP-2 concentration was associated with improved pain in men and patients with painful filling. Our results suggest these urinary biomarkers may be useful in monitoring urological chronic pelvic pain syndrome symptom changes with respect to both urinary severity and pain severity. With further testing, they may represent objective biological measures of urological chronic pelvic pain syndrome progression and/or resolution while also providing insight into the pathophysiology of urological chronic pelvic pain syndrome.

Postpartum human breast milk levels of neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinase-9 (MMP-9)/NGAL complex in normal and pregnancies complicated with insulin-dependent gestational diabetes mellitus. A prospective pilot case-control study

Neutrophil gelatinase-associated lipocalin (NGAL) and its complex with matrix metalloproteinase-9 (MMP-9) are present in a variety of human tissues and extracellular fluids. The aim of this pilot prospective case-control study was to detect NGAL and MMP-9/NGAL complex in human breast milk postpartum in women with normal and pregnancies that developed insulin-depended gestational diabetes mellitus (iGDM). We detected both biomarkers in human breast milk and concentrations were determined at the first day of colostrum secretion and two days after, in 22 normal pregnancies and 13 pregnancies with iGDM. Mean NGAL concentration decreased significantly from the first to the second sample, in both groups. Mean MMP-9/NGAL complex concentration decreased also significantly from the first to the second sample in normal pregnancies. Mean complex concentration was significantly higher in diabetic pregnancies compared to normal ones in the second sample.IMPACT STATEMENTWhat is already known on this subject? There is limited information on the presence of Neutrophil gelatinase-associated lipocalin (NGAL) in human milk and its physiological role.What the results of this study add? It is the first time that MMP-9/NGAL complex is detected in human milk in both normal and pregnancies complicated with insulin-depended gestational diabetes mellitus (iGDM). We confirm the presence of NGAL in colostrum of normal pregnancies and for the first time we detected NGAL in milk of pregnancies with iGDM. Concentrations of NGAL and MMP-9/NGAL complex tend to lessen postpartum in both groups. Pregnancies with iGDM compared to normal ones showed significantly higher concentration of MMP-9/NGAL complex two days after the beginning of lactation.What the implications are of these findings for clinical practice and/or further research? Further studies are necessary to determine the levels of NGAL and MMP-9/NGAL complex in human milk postpartum in normal and pathological pregnancies. Taking into consideration the well-established NGAL’s ability to act as a bacteriostatic agent and its mucosal healing activity in gastrointestinal track, early breastfeeding of neonates is a logical recommendation. Finally, new studies on the actual physiological role of milk NGAL in neonates are necessary.

The levels of matrix metalloproteinase-9 and neutrophil gelatinase-associated lipocalin in different stages of endometriosis

This study was designed to explore matrix metalloproteinase-9 (MMP-9), neutrophil gelatinase-associated lipocalin (NGAL) levels and MMP-9/NGAL ratio in women with and without endometriosis diagnosed surgically and/or histopathologically. The correlation between biomarkers and the severity of the disease is analysed. The revised American Fertility Society classification system was used to determine the severity of endometriosis. Serum MMP-9 and Ca125, urine NGAL levels were measured in all participants. Serum MMP-9 levels were significantly higher in the study group (n = 60) compared to controls (n = 31) (15.0 pg/mL (6.0–143.0) vs. 12.0 (4.0–18.0), respectively; p=.002). MMP-9 levels were significantly higher in severe endometriosis compared to mild endometriosis subgroups (p<.001). No significant difference was found between NGAL levels in study and control groups (p>.05). The diagnostic value of MMP-9 and NGAL is not superior than CA-125 for endometriosis. Nevertheless, MMP-9 might be a potential predictive marker for advanced stage of the disease.Impact StatementWhat is already known on this subject? The gold standard diagnostic test for diagnosis of endometriosis is laparoscopy combined with histopathological confirmation of eutopic endometrial glands and/or stroma. Both invasiveness and possible accompanying complications limit the preference regarding the surgical approach. Among non-invasive markers none has been accepted as gold standard neither for diagnosis nor for determining the severity of the disease. MMPs are extracellular endopeptidases, which have a significant role in degradation and remodelling of extracellular matrix for cellular migration and invasion. Among these, MMP-9 has been shown to be higher in eutopic/ectopic endometrial tissue in women with endometriosis and has been suggested to have a role in pathogenesis of endometriosis by promoting invasion of the endometriotic lesions. NGAL is an acute phase protein, which is involved in a variety of physiological and pathophysiological processes. The molecule has also been revealed to correlate with endometriosis pathophysiology through the epithelial–mesenchymal transition process which is the basis for the onset of endometriosis. But also, NGAL which composes a complex with MMP-9 (MMP-9 and NGAL complex), has been shown to protect MMP-9 from autodegradation in vitro which might be a contributing factor for endometriosis pathophysiology.What the results of this study add? MMP-9 cut-off level for prediction of severe endometriosis is a novel finding obtained from this study with acceptable sensitivity and specificity. On the other hand, NGAL seems to have no significant value either for diagnosis of for determining severity of the disease. After all, MMP-9 might be an easy use acceptable biomarker for endometriosis but further studies on larger populations are needed.What the implications are of these findings for clinical practice and/or further research? MMP might be a potential non-invasive predictive marker for advanced stage disease.

Neutrophil Gelatinase Associated Lipocalin (NGAL) for Identification of Unstable Plaques in Patients with Asymptomatic Carotid Stenosis

Neutrophil gelatinase associated lipocalin (NGAL) and matrix metalloproteinase (MMP)-9/NGAL complex were investigated in asymptomatic patients with carotid artery stenosis including gender specific differences aiming at vulnerable plaques prone to embolisation. Serum NGAL and MMP-9/NGAL levels were analysed in 83 patients with asymptomatic carotid artery stenosis. Pre-operative ultrasound and post-endarterectomy histology of carotid atherosclerotic lesions were evaluated. Patients with vulnerable plaques, as determined by ultrasound (plaques with decreased echogenicity) and histological analysis (type VI according to the classification of the American Heart Association), displayed the highest levels of NGAL and MMP-9/NGAL complex (p=.0003 and p=.0078, respectively). Grade VI plaques were primarily detected in patients with "soft" plaques (12 type VI plaques in 25 patients), but also in patients with mixed (four of 19) and calcified (three of 39) plaques according to ultrasound. Higher grade carotid artery stenosis (≥90%) was not associated with elevated NGAL levels. The receiver operating characteristic curve analysis detecting grade VI lesions yields an area under the curve (AUC)=0.85, with respect to soft plaque on ultrasound the AUC=0.86. There were no gender specific differences in levels of NGAL 80.9 (37.7) ng/mL in women vs. 76.7 (36.3) ng/mL in men, p=.607) nor of MMP-9/NGAL 33.0 (18.2-55.5) ng/mL in women vs. 36.7 (20.2-54.0) ng/mL in men, p=.969. Likewise, there were no gender associated differences in vulnerable plaque characteristics: either for grade VI plaques (17.9% vs. 27.3%, p=.582) or for the presence of soft plaques as evaluated by ultrasound (35.9% vs. 25%, p=.503). Circulating NGAL and MMP-9/NGAL are significantly increased in asymptomatic patients with vulnerable carotid atherosclerotic plaques independent of gender. Accordingly, serum NGAL may be proposed as a valuable biomarker for the detection of unstable carotid plaques in asymptomatic patients, who can then be selected for early carotid endarterectomy or stenting.

Matrix metalloproteinase and heparin-stimulated serine proteinase activities in post-prostate massage urine of men with prostate cancer

Proteinases secreted by the prostate gland have a reproductive function in cleaving proteins in the ejaculate and in the female reproductive tract, but some may have a fundamental role in disease and pathological processes including cancer. The purpose of this study was to determine if there were differences in proteinase activities in urine samples collected following prostate massage of men positive (CaP) or negative (no evidence of malignancy, NEM) for biopsy determined prostate cancer. Matrix metalloproteinase (MMP) and serine proteinase activities were detected using protein substrate zymography. There were no differences in activities of MMP-2, proMMP-9, and MMP-9/NGAL (neutrophil gelatinase associated lipocalin) complex (gelatin substrate) in men with detected prostate cancer, although the latter two were somewhat diminished. A caseinolytic activity of about 75kDa inhibited by calcium did not differ between the NEM and CaP groups. Heparin stimulated calcium sensitive gelatinolytic activities of approximately 22, 42, and 60kDa, but did not affect activities of MMP-2, MMP-9, or the 75kDa caseinolytic activity. The 22, 42, and 60kDa activities appear to be serine proteinases since they were inhibited by benzamidine. There was a significant decrease in the 22kDa heparin-stimulated serine proteinase activity in urines of men with cancer. Proteinase expression and activities, perhaps in combination with other potential markers, may prove useful in urine for detection and evaluation of prostate cancer.

NGAL and MMP-9/NGAL as biomarkers of plaque vulnerability and targets of statins in patients with carotid atherosclerosis.

Neutrophil gelatinase associated lipocalin (NGAL) is expressed in atherosclerotic lesions and was recently implicated in the pathogenesis of cardiovascular pathologies. Statins are known to exert stabilizing effects on atherosclerotic plaque. The aims of our study were (1) to investigate the association of serum NGAL and metalloproteinase (MMP)-9/NGAL complex with the vulnerability of the atherosclerotic plaque, and (2) to reveal the effects of statin treatment on circulating NGAL and MMP-9/NGAL levels in patients with carotid artery stenosis. We examined the levels of NGAL and MMP-9/NGAL in blood samples from 136 patients with carotid artery stenosis by specific enzyme-linked immunosorbent assays. Patients with vulnerable plaques, as determined by ultrasound (plaques with decreased echogenicity) and histological analysis (type VI according to the classification of American Heart Association [AHA]), displayed the highest levels of NGAL (both p<0.0001) and MMP-9/NGAL complex (p=0.0004 and p=0.004, respectively). Moreover, patients with symptomatic carotid atherosclerosis had significantly higher NGAL levels compared to asymptomatic patients (p=0.0007). The statin-treated group (n=108) demonstrated lower NGAL (73.9 vs. 128.0 μg/L, p<0.0001) and MMP-9/NGAL (28.9 vs. 40.6 μg/L, p=0.046) as compared to the non-statin group (n=28). Furthermore, in multivariate regression analysis NGAL, but not MMP-9/NGAL levels, were independently associated with symptomatic carotid artery stenosis. In addition, statin treatment was independently associated with lower NGAL levels. Circulating NGAL and MMP-9/NGAL are associated with plaque vulnerability in patients with carotid artery stenosis. Statin treatment could contribute to plaque stabilization by reducing circulating NGAL and MMP-9/NGAL levels.

Identification of novel non-invasive biomarkers of urinary chronic pelvic pain syndrome: findings from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network.

To examine a series of candidate markers for urological chronic pelvic pain syndrome (UCPPS), selected based on their proposed involvement in underlying biological processes so as to provide new insights into pathophysiology and suggest targets for expanded clinical and mechanistic studies. Baseline urine samples from Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network study participants with UCPPS (n = 259), positive controls (PCs; chronic pain without pelvic pain, n = 107) and healthy controls (HCs, n = 125) were analysed for the presence of proteins that are suggested in the literature to be associated with UCPPS. Matrix metalloproteinase (MMP)-2, MMP-9, MMP-9/neutrophil gelatinase-associated lipocalin (NGAL) complex (also known as Lipocalin 2), vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGF-R1) and NGAL were assayed and quantitated using mono-specific enzyme-linked immunosorbent assays for each protein. Log-transformed concentration (pg/mL or ng/mL) and concentration normalized to total protein (pg/μg) values were compared among the UCPPS, PC and HC groups within sex using the Student's t-test, with P values adjusted for multiple comparisons. Multivariable logistic regression and receiver-operating characteristic curves assessed the utility of the biomarkers in distinguishing participants with UCPPS and control participants. Associations of protein with symptom severity were assessed by linear regression. Significantly higher normalized concentrations (pg/μg) of VEGF, VEGF-R1 and MMP-9 in men and VEGF concentration (pg/mL) in women were associated with UCPPS vs HC. These proteins provided only marginal discrimination between UCPPS participants and HCs. In men with UCCPS, pain severity was significantly positively associated with concentrations of MMP-9 and MMP-9/NGAL complex, and urinary severity was significantly positively associated with MMP-9, MMP-9/NGAL complex and VEGF-R1. In women with UCPPS, pain and urinary symptom severity were associated with increased normalized concentrations of MMP-9/NGAL complex, while pain severity alone was associated with increased normalized concentrations of VEGF, and urinary severity alone was associated with increased normalized concentrations of MMP-2. Pain severity in women with UCPPS was significantly positively associated with concentrations of all biomarkers except NGAL, and urinary severity with all concentrations except VEGF-R1. Altered levels of MMP-9, MMP-9/NGAL complex and VEGF-R1 in men, and all biomarkers in women, were associated with clinical symptoms of UCPPS. None of the evaluated candidate markers usefully discriminated UCPPS patients from controls. Elevated VEGF, MMP-9 and VEGF-R1 levels in men and VEGF levels in women may provide potential new insights into the pathophysiology of UCPPS.

Concomitant elevations of MMP-9, NGAL, proMMP-9/NGAL and neutrophil elastase in serum of smokers with chronic obstructive pulmonary disease.

A growing body of evidence points towards smoking‐related phenotypic differences in chronic obstructive pulmonary disease (COPD). As COPD is associated with systemic inflammation, we determined whether smoking status is related to serum levels of matrix metalloproteinase‐9 (pro‐ and active MMP‐9), neutrophil gelatinase‐associated lipocalin (NGAL) and the proMMP‐9/NGAL complex in patients with COPD. Serum samples were collected in 100 stable‐phase COPD patients (82 smokers, 18 never‐smokers) and 28 healthy adults (21 smokers, 7 never‐smokers). Serum levels of studied factors were measured in ELISA. Our data provide the first evidence of simultaneously elevated serum levels of MMP‐9, NGAL and proMMP‐9/NGAL in COPD smokers. While the triad discriminated between smokers and non‐smokers in the COPD group, MMP‐9 and proMMP‐9/NGAL (but not NGAL) discriminated between smokers with and without COPD. Adjustment for age and smoking pack‐years did not alter the findings. Serum MMP‐9, NGAL and proMMP‐9/NGAL levels were not correlated with the GOLD stage or FEV1 decline. Furthermore, serum levels of neutrophil elastase (NE) and MMP‐3 (but not of IL‐6 and MMP‐12) were also higher in COPD smokers than in healthy smokers before and after adjustment for age and pack‐years. Among COPD smokers, levels of MMP‐9, NGAL and proMMP‐9/NGAL were positively correlated with NE (P < 0.0001) but not with the remaining factors. Gelatin zymography detected proMMP‐9 in serum samples of healthy and COPD smoking groups. Our results suggest that associated serum levels of proMMP‐9, NGAL, proMMP‐9/NGAL and NE may reflect the state of systemic inflammation in COPD related to cigarette smoking.

Prediction of pre-eclampsia combining NGAL and other biochemical markers with Doppler in the first and/or second trimester of pregnancy. A pilot study.

ObjectiveTo determine the performance of maternal characteristics, Doppler and a set of biochemical markers for pre-eclampsia (PE) screening at 11+0 to 13+6 and 20+1 to 25+6 weeks’ gestation. Study designProspectively enrolled women at 11+0 to 13+6 and 20+1 to 25+6 weeks. Maternal characteristics, uterine artery pulsatility index (UtA-PI), ductus venosus pulsatility index (DV-PI) and serum biomarkers including pregnancy associated plasma protein – A (PAPP-A), placental growth factor (PlGF), soluble fms-like tyrosine kinase 1 (sFlt-1), s-Flt-1/PLGF ratio, asymmetric dimethylarginine (ADMA), matrix metalloproteinase 9 (MMP-9), neutrophil gelatinase-associated lipocalin (NGAL) and MMP-9/NGAL complex were recorded. ResultsCombination of NGAL and BMI in a logistic regression model detected 70% of PE in the first trimester (p=0.001). Including UtA-PI and DV-PI in the model sensitivity reached 77.8% with 96.6% specificity (p=0.004). Combination of second trimester NGAL and s-Flt-1/PLGF ratio yield specificity 100% (p=0.001). Combination of second trimester UtA-PI with first trimester NGAL, BMI and age detected 80% of PE with specificity 91.9% (p=0.001). ConclusionCombination of NGAL, maternal characteristics and Doppler parameters in the first and/or second trimester can detect a consistent number of PE pregnancies. NGAL is a potent new biomarker for the prediction of preeclampsia.

Evaluation of MMP-2, MMP-9, TIMP-1, TIMP-2, NGAL and MMP-9/NGAL complex in urine and sera from patients with bladder cancer.

The identification of biomarkers in urine or serum samples from patients with bladder cancer is urgently required for the development of non-invasive methods for the diagnosis of bladder carcinoma and to facilitate follow-up surveillance, to combat the high progression and recurrence rates of this type of cancer. The current study measured the content of matrix metalloproteinase (MMP)-2 and -9, as well as tissue inhibitor of metalloproteinase (TIMP)-1 and -2 in the urine and sera of 41 patients with bladder cancer by ELISA. The association between levels of MMP-2 and -9 and TIMP-1 and -2, and tumor grade and stage were investigated to verify whether these molecules are involved in tumor differentiation. Statistical analysis of the data revealed that urinary TIMP-1 levels were significantly higher in the high grade group compared with those of the low grade samples (P=0.022). The results also revealed a significantly differing distribution of TIMP-1 expression between Ta and T1 stage specimens (P=0.040). The corresponding area under the curves (AUCs) were 0.72, with a sensitivity of 0.70 and specificity of 0.75. In addition, neutrophil gelatinase-associated lipocalin (NGAL) and MMP-9/NGAL complex levels in the sera were measured. All molecules evaluated were detected in the sera of the patients studied. In particular, tumors staged as non-muscle invasive (Ta and T1), demonstrated significantly higher NGAL levels compared with those of muscle invasive (>T1) bladder cancer (32.8 ng/ml vs. 16.2 ng/ml; P=0.029). The discriminatory ability of NGAL expression was confirmed by receiver operating characteristic curve analysis that revealed an AUC of 0.75, a sensitivity of 0.88 and a specificity of 0.67. These data indicated that urinary TIMP-1 and serum NGAL may be useful non-invasive biomarkers to provide clinical information for bladder cancer disease management. Multicenter, prospective studies are required to confirm these preliminary results.

Treatment of hypertension in patients with coronary artery disease: A scientific statement from the American Heart Association, American College of Cardiology, and American Society of Hypertension

Neutrophil gelatinase associated lipocalin (NGAL) and matrix metalloproteinase (MMP)-9/NGAL complex were investigated in asymptomatic patients with carotid artery stenosis including gender specific differences aiming at vulnerable plaques prone to embolisation.Serum NGAL and MMP-9/NGAL levels were analysed in 83 patients with asymptomatic carotid artery stenosis. Pre-operative ultrasound and post-endarterectomy histology of carotid atherosclerotic lesions were evaluated.Patients with vulnerable plaques, as determined by ultrasound (plaques with decreased echogenicity) and histological analysis (type VI according to the classification of the American Heart Association), displayed the highest levels of NGAL and MMP-9/NGAL complex (p = .0003 and p = .0078, respectively). Grade VI plaques were primarily detected in patients with “soft” plaques (12 type VI plaques in 25 patients), but also in patients with mixed (four of 19) and calcified (three of 39) plaques according to ultrasound. Higher grade carotid artery stenosis (≥90%) was not associated with elevated NGAL levels. The receiver operating characteristic curve analysis detecting grade VI lesions yields an area under the curve (AUC) = 0.85, with respect to soft plaque on ultrasound the AUC = 0.86. There were no gender specific differences in levels of NGAL 80.9 (37.7) ng/mL in women vs. 76.7 (36.3) ng/mL in men, p = .607) nor of MMP-9/NGAL 33.0 (18.2–55.5) ng/mL in women vs. 36.7 (20.2–54.0) ng/mL in men, p = .969. Likewise, there were no gender associated differences in vulnerable plaque characteristics: either for grade VI plaques (17.9% vs. 27.3%, p = .582) or for the presence of soft plaques as evaluated by ultrasound (35.9% vs. 25%, p = .503).Circulating NGAL and MMP-9/NGAL are significantly increased in asymptomatic patients with vulnerable carotid atherosclerotic plaques independent of gender. Accordingly, serum NGAL may be proposed as a valuable biomarker for the detection of unstable carotid plaques in asymptomatic patients, who can then be selected for early carotid endarterectomy or stenting.

Neutrophil Gelatinase-Associated Lipocalin (NGAL), Pro-Matrix Metalloproteinase-9 (pro-MMP-9) and Their Complex Pro-MMP-9/NGAL in Leukaemias

Matrix metalloproteinase (MMP)-9 and neutrophil gelatinase-associated lipocalin (NGAL) have gained attention as cancer biomarkers. The inactive zymogen form of MMP-9 (pro-MMP-9) also exists as a disulphide-linked heterodimer bound to NGAL in humans. Leukaemias represent a heterogeneous group of neoplasms, which vary in their clinical behavior and pathophysiology. In this review, we summarize the current literature on the expression profiles of pro-MMP-9 and NGAL as prognostic factors in leukaemias. We also report the expression of the pro-MMP-9/NGAL complex in these diseases. We discuss the roles of (pro)-MMP-9 (active and latent forms) and NGAL in tumour development, and evaluate the mechanisms by which pro-MMP-9/NGAL may influence the actions of (pro)-MMP-9 and NGAL in cancer. Emerging knowledge about the coexpression and the biology of (pro)-MMP-9, NGAL and their complex in cancer including leukaemia may improve treatment outcomes.

Maternal serum levels of neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase-9 (MMP-9) and their complex MMP-9/NGAL in pregnancies with preeclampsia and those with a small for gestational age neonate: a longitudinal study

The aim of this study was to determine maternal serum concentrations of neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase-9 (MMP-9), and MMP-9/NGAL complex longitudinally in pregnancy, in normal pregnancies, in pregnancies that developed preeclampsia and in pregnancies that delivered a small for gestational age infant (SGA). Neutrophil gelatinase-associated lipocalin, MMP-9, and MMP-9/NGAL were determined in the first, second, and third trimesters in 33 normal pregnancies, 12 pregnancies complicated by preeclampsia, and 14 pregnancies that delivered a SGA neonate. Median NGAL concentration (ng/mL) in normal pregnancies increased significantly from 12.8 in the first trimester to 25.9 in the second trimester (p = 0,002) and 48.0 (p < 0.0001) in the third trimester. In preeclamptic pregnancies, NGAL was significantly higher, compared with normal pregnancies, in the first (30.9; p = 0.006) and second (44.6; p = 0.015) trimesters. MMP-9 and MMP-9/NGAL complex concentrations in preeclamptic pregnancies did not differ significantly from normal pregnancies in either trimester. Pregnancies with an SGA infant did not have different marker concentrations in either trimester, compared with normal pregnancies. Maternal serum NGAL, MMP-9, and MMP-9/NGAL complex concentrations tend to increase during pregnancy in normal and preeclamptic pregnancies. NGAL was significantly elevated in the first and second trimesters, in pregnancies that later developed preeclampsia.

Evaluation of neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase-9 (MMP-9) and their complex MMP-9/NGAL in sera and urine of patients with kidney tumors

Recent evidence suggests that neutrophil gelatinase-associated lipocalin (NGAL) is required for the development and/or progression of benign and malignant disease, and is overexpressed in several types of tumor. Matrix metalloproteinase-9 (MMP-9), by degrading components of the extracellular matrix and thus promoting the release of growth factors, is important in tumor growth and tumorigenicity. NGAL protects MMP-9 from proteolytic degradation and enhances its enzymatic activities by binding and forming the MMP-9/NGAL complex. Therefore, NGAL, MMP-9 and their complex MMP-9/NGAL have been proposed as soluble biomarkers for numerous malignancies. In the present study, we measured the concentration of these molecules in sera and urine of patients with kidney disease using ELISA. Of these patients, 16 had clear cell renal cell carcinoma (ccRCC) and 4 had oncocytoma. Sera and urine samples of 53 healthy patients were used as controls. In sera, MMP-9 was enhanced in ccRCC patients compared with oncocytoma patients. In urine, the most abundant molecule was NGAL and its mean value was higher in cancer patients. However, there was a broad overlap of the data and we did not identify any correlation with disease type, stage or grade. Therefore, these molecules may not be useful as biomarkers for predicting kidney carcinoma.

Urinary MMP-9/NGAL complex in children with acute cystitis

The matrix metalloproteinase-9 (MMP-9) and neutrophil gelatinase associated lipocalin (NGAL) are shown to increase in an inflammatory situation. Based on our previous reports that NGAL can be detected in the urine of children with urinary tract infection (UTI), we also asked whether MMP-9/NGAL complex could be detected in the urine of children with UTI. This multicenter, prospective study was conducted between October 2009 and October 2010. Seventy-one patients with symptomatic culture proven UTI, 37 asymptomatic children with contaminated urine and 37 healthy children were recruited. Mean uMMP-9/NGAL/Cr levels were significantly higher in the UTI group than in the control group (p < 0.0001). According to ROC analysis, the optimal cut-off level was 0.08 ng/mg to predict UTI. Using a cut-off value, sensitivity and specificity were 98.6 and 97.3%, respectively. The mean levels of uMMP-9/NGAL/cr in the UTI group were also significantly higher than those in the contamination group (p < 0.0001). There was no statistically significant difference between contamination group and the control group (p = 0.21). The mean uMMP-9/NGAL/Cr in the UTI group were significantly higher before treatment than after treatment (p < 0.0001). The area under the curve was 0.997 (SE: 0.002, 95% CI: 0.993 to 1.001) for uMMP-9/NGAL/Cr. Urinary MMP-9/NGAL/Cr level was also correlated with positive urine nitrite test, positive urine leukocyte esterase reaction and renal scarring (p = 0.0001, p = 0.0001, p = 0.04, respectively) whereas was not correlated to leukocytosis and positive CRP level in serum. Urine MMP-9/NGAL/cr can be used as a diagnostic biomarker for UTI in children. Identification of NGAL-MMP-9/cr levels in the urine of suspected UTI patients may also be useful to differentiate between contamination and infection and for monitoring of treatment response in children.

Matrix metalloproteinases are elevated in the urine of patients with endometriosis

In a prospective, blinded, longitudinal study MMP-2, MMP-9, and MMP-9/neutrophil gelatinase-associated lipocalin were significantly more likely to be detected in the urine of patients with endometriosis than in controls.