Early matrix metalloproteinase-9 concentration in the first 48 h after aneurysmal subarachnoid haemorrhage predicts delayed cerebral ischaemia: An observational study.

BACKGROUND: Delayed cerebral ischaemia from vasospasm is an important cause of complications and death after aneurysmal subarachnoid haemorrhage. There is currently no established biomarker for identifying patients at high risk of delayed cerebral ischaemia. OBJECTIVE: Considering the important role of inflammation in the pathogenesis of delayed cerebral ischaemia, we investigated whether matrix metalloproteinase-9 (MMP-9) may be an efficient biomarker for predicting elayed cerebral ischaemia after subarachnoid haemorrhage. DESIGN: Single-centre prospective observational study. SETTING: Neuroscience Critical Care Unit of a teaching hospital. PARTICIPANTS: Thirty consecutive patients with severe subarachnoid haemorrhage requiring external ventricular drainage were enrolled during 2013 and 2014. INTERVENTIONS: Blood and cerebrospinal fluid (CSF) were sampled within the first 24 h and between 48 and 72 h after admission. We evaluated the activity and concentrations of MMP-9 and endothelin-1 with zymography and ELISA. Patients were allocated to groups with delayed cerebral ischaemia (n = 16) or without delayed cerebral ischaemia (n = 14). RESULTS: Within 24 h, median [interquartile range] MMP-9 concentrations in CSF were significantly higher in patients with delayed cerebral ischaemia (47 [21 to 102] ng ml) than in those without delayed cerebral ischaemia (4 [2 to 13] ng ml, P = 0.001). CSF MMP-9 activity and endothelin-1 concentrations were correlated (r = 0.6, P = 0.02). The areas under the receiver operating characteristic curves were 0.73 (95% confidence interval [0.53 to 0.87]) and 0.91 (95% confidence interval [0.75 to 0.98]) for MMP-9 concentrations in plasma and CSF, respectively, at 24 h to predict delayed cerebral ischaemia CSF MMP-9 concentrations more than 14.3 ng ml at 24 h predicted the occurrence of delayed cerebral ischaemia with a sensitivity and specificity of 88 and 86%, respectively. After multivariate logistic analysis, only CSF MMP-9 concentrations at 24 h predicted the occurrence of delayed cerebral ischaemia (P = 0.01). CONCLUSION: MMP-9 concentrations in both plasma and CSF, measured within 48 h after subarachnoid haemorrhage, were highly predictive of the occurrence of delayed cerebral ischaemia within the first 2 weeks. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02397759.

Immediate Postnatal Overfeeding in Rats Programs Aortic Wall Structure Alterations and Metalloproteinases Dysregulation in Adulthood.

BACKGROUND: Alterations in the nutritional perinatal environment, such as intrauterine growth retardation with subsequent postnatal catch-up growth, program cardiovascular disease in adulthood, possibly through alterations in matrix metalloproteinase (MMP)-2 and -9. However, experimental evidences demonstrating that changes in the nutritional perinatal environment can program MMP-2 and -9 with subsequent alterations of vessel wall are lacking. AIM: The current study evaluated whether immediate postnatal overfeeding is able to alter vascular morphological indexes and circulating and/or vascular MMP2-2 and -9 status. METHODS: Aortic morphology (wall thickness and percentage of incomplete elastin lamellae) and circulating and aortic MMP-2 and -9 activity (measured by gelatin zymography) and aortic MMP-2 and -9 mRNA (measured by reverse transcription polymerase chain reaction (RT-PCR)) were studied in adult male rats overfed (OF) or normofed (NF) during the immediate postnatal period. RESULTS: Postnatal overfeeding induced early onset obesity. Adult OF rats presented with increased blood pressure and circulating MMP-2 and -9 activity. In the thoracic aorta, postnatal overfeeding increased wall thickness and decreased elastin integrity (as demonstrated by an increased percentage of incomplete elastin lamellae). OF rats showed enhanced aortic MMP-2 activity and MMP-9 mRNA levels. Circulating and aortic MMP-2 activity correlated positively with the percentage of incomplete elastin lamellae and aortic wall thickness, respectively. CONCLUSION: Our data demonstrate for the first time that immediate postnatal nutritional programming induces increases in circulating and aortic MMP-2 activity with parallel aortic wall alterations, such as decreased elastin integrity and enhanced thickening, showing that this experimental model is suitable for the study of perinatal nutritional programming of vascular functions.

The plasminogen activation system modulates differently adipogenesis and myogenesis of embryonic stem cells.

Regulation of the extracellular matrix (ECM) plays an important functional role either in physiological or pathological conditions. The plasminogen activation (PA) system, comprising the uPA and tPA proteases and their inhibitor PAI-1, is one of the main suppliers of extracellular proteolytic activity contributing to tissue remodeling. Although its function in development is well documented, its precise role in mouse embryonic stem cell (ESC) differentiation in vitro is unknown. We found that the PA system components are expressed at very low levels in undifferentiated ESCs and that upon differentiation uPA activity is detected mainly transiently, whereas tPA activity and PAI-1 protein are maximum in well differentiated cells. Adipocyte formation by ESCs is inhibited by amiloride treatment, a specific uPA inhibitor. Likewise, ESCs expressing ectopic PAI-1 under the control of an inducible expression system display reduced adipogenic capacities after induction of the gene. Furthermore, the adipogenic differentiation capacities of PAI-1(-/-) induced pluripotent stem cells (iPSCs) are augmented as compared to wt iPSCs. Our results demonstrate that the control of ESC adipogenesis by the PA system correspond to different successive steps from undifferentiated to well differentiated ESCs. Similarly, skeletal myogenesis is decreased by uPA inhibition or PAI-1 overexpression during the terminal step of differentiation. However, interfering with uPA during days 0 to 3 of the differentiation process augments ESC myotube formation. Neither neurogenesis, cardiomyogenesis, endothelial cell nor smooth muscle formation are affected by amiloride or PAI-1 induction. Our results show that the PA system is capable to specifically modulate adipogenesis and skeletal myogenesis of ESCs by successive different molecular mechanisms.

Circulating matrix metalloproteinases in infective endocarditis: a possible marker of the embolic risk.

BACKGROUND: Embolic events (EE) in infective endocarditis (IE) are caused by fragmentation of vegetations or valvular tissue. Vegetation length is considered to be the most potent predictor of EE, but does not take into account the degree of friability of the vegetation and of the surrounded infected tissue. Matrix metalloproteinases (MMPs) are enzymes involved in degradation of matrix extracellular components and play a role in the pathophysiology of IE. We aimed to determine whether, in addition to the vegetation size, circulating MMPs could provide accurate predictive value of embolism in IE. METHODS: Among 145 patients referred for a native valve IE, we prospectively included 16 patients who experienced EE during antibiotic therapy (new-EE) and 30 patients without new-EE and treated without valvular surgery. A control group of 38 patients with a degenerative valvular heart disease was also included. In addition to clinical, microbiological and echocardiographic assessment, blood MMPs and their inhibitors were assayed in all patients at admission. RESULTS: MMP-9 serum level was significantly higher in patients with new-EE compared to controls (median [interquartile range]; 250 ng/mL [175-455] vs. 111 ng/mL [70-144], respectively; p<0.0001) and patients with no new-EE (250 ng/mL [175-455] vs. 138 ng/mL [95-232]; p<0.01). A higher MMP-9 activity in patients who experienced new-EE was further confirmed by gelatin zymography analysis. Circulating MMP-9 remains a predictor of new-EE after adjustment for vegetation length and other potential confounders. This parameter provided incremental predictive value over vegetation measurements. CONCLUSIONS: MMP-9 serum level is associated with the risk of embolism during IE. This marker might help physicians in the management of the disease, but further prospective studies are need to confirm these preliminary results.

Polymorphism A36G of the tumor necrosis factor receptor 1 gene is associated with PAI-1 levels in obese women.

The tumor necrosis factor (TNF) pathway may be implicated in etiopathogenesis of PAI-1 overexpression during obesity. The aim of this study was to investigate the influence of polymorphism A36G of the TNF receptor 1 (TNFRSF1A +36A/G) on plasma concentrations of PAI-1 in 163 obese (31 with the metabolic syndrome, MetS) and 150 lean, healthy women. Genotypic and allele frequencies did not significantly differ between obese and lean subjects. TNFRSF1A genotypes were significantly associated with sTNFR1 plasma levels in obese women only (p < 0.01); TNFRSF1A +36G/G obese carriers exhibited higher sTNFR1 and PAI-1 levels than A carriers (p < 0.01 and p < 0.05, respectively). In obese women, the presence of the MetS significantly potentiated the elevation of sTNFR1 and PAI-1 levels observed in the TNFRSF1A + 36G/G carriers. Our results suggest that association between TNFRSF1A +36G/G genotype and the MetS renders obese women more prone to activation of the TNF pathway reflected by high circulating sTNFR1 and PAI-1 levels.